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
*, 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
*, char *data
);
469 static void ssh_pkt_addstring_data(struct Packet
*, char *data
, int len
);
470 static void ssh_pkt_addstring(struct Packet
*, 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_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
;
670 struct ssh_x11_channel
{
673 struct ssh_pfd_channel
{
680 * 2-3-4 tree storing remote->local port forwardings. SSH-1 and SSH-2
681 * use this structure in different ways, reflecting SSH-2's
682 * altogether saner approach to port forwarding.
684 * In SSH-1, you arrange a remote forwarding by sending the server
685 * the remote port number, and the local destination host:port.
686 * When a connection comes in, the server sends you back that
687 * host:port pair, and you connect to it. This is a ready-made
688 * security hole if you're not on the ball: a malicious server
689 * could send you back _any_ host:port pair, so if you trustingly
690 * connect to the address it gives you then you've just opened the
691 * entire inside of your corporate network just by connecting
692 * through it to a dodgy SSH server. Hence, we must store a list of
693 * host:port pairs we _are_ trying to forward to, and reject a
694 * connection request from the server if it's not in the list.
696 * In SSH-2, each side of the connection minds its own business and
697 * doesn't send unnecessary information to the other. You arrange a
698 * remote forwarding by sending the server just the remote port
699 * number. When a connection comes in, the server tells you which
700 * of its ports was connected to; and _you_ have to remember what
701 * local host:port pair went with that port number.
703 * Hence, in SSH-1 this structure is indexed by destination
704 * host:port pair, whereas in SSH-2 it is indexed by source port.
706 struct ssh_portfwd
; /* forward declaration */
708 struct ssh_rportfwd
{
709 unsigned sport
, dport
;
712 struct ssh_portfwd
*pfrec
;
714 #define free_rportfwd(pf) ( \
715 ((pf) ? (sfree((pf)->sportdesc)) : (void)0 ), sfree(pf) )
718 * Separately to the rportfwd tree (which is for looking up port
719 * open requests from the server), a tree of _these_ structures is
720 * used to keep track of all the currently open port forwardings,
721 * so that we can reconfigure in mid-session if the user requests
725 enum { DESTROY
, KEEP
, CREATE
} status
;
727 unsigned sport
, dport
;
730 struct ssh_rportfwd
*remote
;
734 #define free_portfwd(pf) ( \
735 ((pf) ? (sfree((pf)->saddr), sfree((pf)->daddr), \
736 sfree((pf)->sserv), sfree((pf)->dserv)) : (void)0 ), sfree(pf) )
739 long length
; /* length of `data' actually used */
740 long forcepad
; /* SSH-2: force padding to at least this length */
741 int type
; /* only used for incoming packets */
742 unsigned long sequence
; /* SSH-2 incoming sequence number */
743 unsigned char *data
; /* allocated storage */
744 unsigned char *body
; /* offset of payload within `data' */
745 long savedpos
; /* temporary index into `data' (for strings) */
746 long maxlen
; /* amount of storage allocated for `data' */
747 long encrypted_len
; /* for SSH-2 total-size counting */
750 * State associated with packet logging
754 struct logblank_t
*blanks
;
757 static void ssh1_protocol(Ssh ssh
, void *vin
, int inlen
,
758 struct Packet
*pktin
);
759 static void ssh2_protocol(Ssh ssh
, void *vin
, int inlen
,
760 struct Packet
*pktin
);
761 static void ssh1_protocol_setup(Ssh ssh
);
762 static void ssh2_protocol_setup(Ssh ssh
);
763 static void ssh_size(void *handle
, int width
, int height
);
764 static void ssh_special(void *handle
, Telnet_Special
);
765 static int ssh2_try_send(struct ssh_channel
*c
);
766 static void ssh2_add_channel_data(struct ssh_channel
*c
, char *buf
, int len
);
767 static void ssh_throttle_all(Ssh ssh
, int enable
, int bufsize
);
768 static void ssh2_set_window(struct ssh_channel
*c
, int newwin
);
769 static int ssh_sendbuffer(void *handle
);
770 static int ssh_do_close(Ssh ssh
, int notify_exit
);
771 static unsigned long ssh_pkt_getuint32(struct Packet
*pkt
);
772 static int ssh2_pkt_getbool(struct Packet
*pkt
);
773 static void ssh_pkt_getstring(struct Packet
*pkt
, char **p
, int *length
);
774 static void ssh2_timer(void *ctx
, long now
);
775 static void do_ssh2_transport(Ssh ssh
, void *vin
, int inlen
,
776 struct Packet
*pktin
);
777 static void ssh2_msg_unexpected(Ssh ssh
, struct Packet
*pktin
);
779 struct rdpkt1_state_tag
{
780 long len
, pad
, biglen
, to_read
;
781 unsigned long realcrc
, gotcrc
;
785 struct Packet
*pktin
;
788 struct rdpkt2_state_tag
{
789 long len
, pad
, payload
, packetlen
, maclen
;
792 unsigned long incoming_sequence
;
793 struct Packet
*pktin
;
796 struct queued_handler
;
797 struct queued_handler
{
799 chandler_fn_t handler
;
801 struct queued_handler
*next
;
805 const struct plug_function_table
*fn
;
806 /* the above field _must_ be first in the structure */
816 unsigned char session_key
[32];
818 int v1_remote_protoflags
;
819 int v1_local_protoflags
;
820 int agentfwd_enabled
;
823 const struct ssh_cipher
*cipher
;
826 const struct ssh2_cipher
*cscipher
, *sccipher
;
827 void *cs_cipher_ctx
, *sc_cipher_ctx
;
828 const struct ssh_mac
*csmac
, *scmac
;
829 void *cs_mac_ctx
, *sc_mac_ctx
;
830 const struct ssh_compress
*cscomp
, *sccomp
;
831 void *cs_comp_ctx
, *sc_comp_ctx
;
832 const struct ssh_kex
*kex
;
833 const struct ssh_signkey
*hostkey
;
834 unsigned char v2_session_id
[SSH2_KEX_MAX_HASH_LEN
];
835 int v2_session_id_len
;
841 int echoing
, editing
;
845 int ospeed
, ispeed
; /* temporaries */
846 int term_width
, term_height
;
848 tree234
*channels
; /* indexed by local id */
849 struct ssh_channel
*mainchan
; /* primary session channel */
850 int ncmode
; /* is primary channel direct-tcpip? */
855 tree234
*rportfwds
, *portfwds
;
859 SSH_STATE_BEFORE_SIZE
,
865 int size_needed
, eof_needed
;
866 int sent_console_eof
;
867 int got_pty
; /* affects EOF behaviour on main channel */
869 struct Packet
**queue
;
870 int queuelen
, queuesize
;
872 unsigned char *deferred_send_data
;
873 int deferred_len
, deferred_size
;
876 * Gross hack: pscp will try to start SFTP but fall back to
877 * scp1 if that fails. This variable is the means by which
878 * scp.c can reach into the SSH code and find out which one it
883 bufchain banner
; /* accumulates banners during do_ssh2_authconn */
888 struct X11Display
*x11disp
;
891 int conn_throttle_count
;
894 int v1_stdout_throttling
;
895 unsigned long v2_outgoing_sequence
;
897 int ssh1_rdpkt_crstate
;
898 int ssh2_rdpkt_crstate
;
899 int ssh_gotdata_crstate
;
900 int do_ssh1_connection_crstate
;
902 void *do_ssh_init_state
;
903 void *do_ssh1_login_state
;
904 void *do_ssh2_transport_state
;
905 void *do_ssh2_authconn_state
;
907 struct rdpkt1_state_tag rdpkt1_state
;
908 struct rdpkt2_state_tag rdpkt2_state
;
910 /* SSH-1 and SSH-2 use this for different things, but both use it */
911 int protocol_initial_phase_done
;
913 void (*protocol
) (Ssh ssh
, void *vin
, int inlen
,
915 struct Packet
*(*s_rdpkt
) (Ssh ssh
, unsigned char **data
, int *datalen
);
918 * We maintain our own copy of a Conf structure here. That way,
919 * when we're passed a new one for reconfiguration, we can check
920 * the differences and potentially reconfigure port forwardings
921 * etc in mid-session.
926 * Values cached out of conf so as to avoid the tree234 lookup
927 * cost every time they're used.
932 * Dynamically allocated username string created during SSH
933 * login. Stored in here rather than in the coroutine state so
934 * that it'll be reliably freed if we shut down the SSH session
935 * at some unexpected moment.
940 * Used to transfer data back from async callbacks.
942 void *agent_response
;
943 int agent_response_len
;
947 * The SSH connection can be set as `frozen', meaning we are
948 * not currently accepting incoming data from the network. This
949 * is slightly more serious than setting the _socket_ as
950 * frozen, because we may already have had data passed to us
951 * from the network which we need to delay processing until
952 * after the freeze is lifted, so we also need a bufchain to
956 bufchain queued_incoming_data
;
959 * Dispatch table for packet types that we may have to deal
962 handler_fn_t packet_dispatch
[256];
965 * Queues of one-off handler functions for success/failure
966 * indications from a request.
968 struct queued_handler
*qhead
, *qtail
;
969 handler_fn_t q_saved_handler1
, q_saved_handler2
;
972 * This module deals with sending keepalives.
977 * Track incoming and outgoing data sizes and time, for
980 unsigned long incoming_data_size
, outgoing_data_size
, deferred_data_size
;
981 unsigned long max_data_size
;
983 long next_rekey
, last_rekey
;
984 char *deferred_rekey_reason
; /* points to STATIC string; don't free */
987 * Fully qualified host name, which we need if doing GSSAPI.
993 * GSSAPI libraries for this session.
995 struct ssh_gss_liblist
*gsslibs
;
999 #define logevent(s) logevent(ssh->frontend, s)
1001 /* logevent, only printf-formatted. */
1002 static void logeventf(Ssh ssh
, const char *fmt
, ...)
1008 buf
= dupvprintf(fmt
, ap
);
1014 static void bomb_out(Ssh ssh
, char *text
)
1016 ssh_do_close(ssh
, FALSE
);
1018 connection_fatal(ssh
->frontend
, "%s", text
);
1022 #define bombout(msg) bomb_out(ssh, dupprintf msg)
1024 /* Functions to leave bits out of the SSH packet log file. */
1026 static void dont_log_password(Ssh ssh
, struct Packet
*pkt
, int blanktype
)
1028 if (conf_get_int(ssh
->conf
, CONF_logomitpass
))
1029 pkt
->logmode
= blanktype
;
1032 static void dont_log_data(Ssh ssh
, struct Packet
*pkt
, int blanktype
)
1034 if (ssh
->logomitdata
)
1035 pkt
->logmode
= blanktype
;
1038 static void end_log_omission(Ssh ssh
, struct Packet
*pkt
)
1040 pkt
->logmode
= PKTLOG_EMIT
;
1043 /* Helper function for common bits of parsing ttymodes. */
1044 static void parse_ttymodes(Ssh ssh
,
1045 void (*do_mode
)(void *data
, char *mode
, char *val
),
1050 for (val
= conf_get_str_strs(ssh
->conf
, CONF_ttymodes
, NULL
, &key
);
1052 val
= conf_get_str_strs(ssh
->conf
, CONF_ttymodes
, key
, &key
)) {
1054 * val[0] is either 'V', indicating that an explicit value
1055 * follows it, or 'A' indicating that we should pass the
1056 * value through from the local environment via get_ttymode.
1058 if (val
[0] == 'A') {
1059 val
= get_ttymode(ssh
->frontend
, key
);
1061 do_mode(data
, key
, val
);
1065 do_mode(data
, key
, val
+ 1); /* skip the 'V' */
1069 static int ssh_channelcmp(void *av
, void *bv
)
1071 struct ssh_channel
*a
= (struct ssh_channel
*) av
;
1072 struct ssh_channel
*b
= (struct ssh_channel
*) bv
;
1073 if (a
->localid
< b
->localid
)
1075 if (a
->localid
> b
->localid
)
1079 static int ssh_channelfind(void *av
, void *bv
)
1081 unsigned *a
= (unsigned *) av
;
1082 struct ssh_channel
*b
= (struct ssh_channel
*) bv
;
1083 if (*a
< b
->localid
)
1085 if (*a
> b
->localid
)
1090 static int ssh_rportcmp_ssh1(void *av
, void *bv
)
1092 struct ssh_rportfwd
*a
= (struct ssh_rportfwd
*) av
;
1093 struct ssh_rportfwd
*b
= (struct ssh_rportfwd
*) bv
;
1095 if ( (i
= strcmp(a
->dhost
, b
->dhost
)) != 0)
1096 return i
< 0 ?
-1 : +1;
1097 if (a
->dport
> b
->dport
)
1099 if (a
->dport
< b
->dport
)
1104 static int ssh_rportcmp_ssh2(void *av
, void *bv
)
1106 struct ssh_rportfwd
*a
= (struct ssh_rportfwd
*) av
;
1107 struct ssh_rportfwd
*b
= (struct ssh_rportfwd
*) bv
;
1109 if (a
->sport
> b
->sport
)
1111 if (a
->sport
< b
->sport
)
1117 * Special form of strcmp which can cope with NULL inputs. NULL is
1118 * defined to sort before even the empty string.
1120 static int nullstrcmp(const char *a
, const char *b
)
1122 if (a
== NULL
&& b
== NULL
)
1128 return strcmp(a
, b
);
1131 static int ssh_portcmp(void *av
, void *bv
)
1133 struct ssh_portfwd
*a
= (struct ssh_portfwd
*) av
;
1134 struct ssh_portfwd
*b
= (struct ssh_portfwd
*) bv
;
1136 if (a
->type
> b
->type
)
1138 if (a
->type
< b
->type
)
1140 if (a
->addressfamily
> b
->addressfamily
)
1142 if (a
->addressfamily
< b
->addressfamily
)
1144 if ( (i
= nullstrcmp(a
->saddr
, b
->saddr
)) != 0)
1145 return i
< 0 ?
-1 : +1;
1146 if (a
->sport
> b
->sport
)
1148 if (a
->sport
< b
->sport
)
1150 if (a
->type
!= 'D') {
1151 if ( (i
= nullstrcmp(a
->daddr
, b
->daddr
)) != 0)
1152 return i
< 0 ?
-1 : +1;
1153 if (a
->dport
> b
->dport
)
1155 if (a
->dport
< b
->dport
)
1161 static int alloc_channel_id(Ssh ssh
)
1163 const unsigned CHANNEL_NUMBER_OFFSET
= 256;
1164 unsigned low
, high
, mid
;
1166 struct ssh_channel
*c
;
1169 * First-fit allocation of channel numbers: always pick the
1170 * lowest unused one. To do this, binary-search using the
1171 * counted B-tree to find the largest channel ID which is in a
1172 * contiguous sequence from the beginning. (Precisely
1173 * everything in that sequence must have ID equal to its tree
1174 * index plus CHANNEL_NUMBER_OFFSET.)
1176 tsize
= count234(ssh
->channels
);
1180 while (high
- low
> 1) {
1181 mid
= (high
+ low
) / 2;
1182 c
= index234(ssh
->channels
, mid
);
1183 if (c
->localid
== mid
+ CHANNEL_NUMBER_OFFSET
)
1184 low
= mid
; /* this one is fine */
1186 high
= mid
; /* this one is past it */
1189 * Now low points to either -1, or the tree index of the
1190 * largest ID in the initial sequence.
1193 unsigned i
= low
+ 1 + CHANNEL_NUMBER_OFFSET
;
1194 assert(NULL
== find234(ssh
->channels
, &i
, ssh_channelfind
));
1196 return low
+ 1 + CHANNEL_NUMBER_OFFSET
;
1199 static void c_write_stderr(int trusted
, const char *buf
, int len
)
1202 for (i
= 0; i
< len
; i
++)
1203 if (buf
[i
] != '\r' && (trusted
|| buf
[i
] == '\n' || (buf
[i
] & 0x60)))
1204 fputc(buf
[i
], stderr
);
1207 static void c_write(Ssh ssh
, const char *buf
, int len
)
1209 if (flags
& FLAG_STDERR
)
1210 c_write_stderr(1, buf
, len
);
1212 from_backend(ssh
->frontend
, 1, buf
, len
);
1215 static void c_write_untrusted(Ssh ssh
, const char *buf
, int len
)
1217 if (flags
& FLAG_STDERR
)
1218 c_write_stderr(0, buf
, len
);
1220 from_backend_untrusted(ssh
->frontend
, buf
, len
);
1223 static void c_write_str(Ssh ssh
, const char *buf
)
1225 c_write(ssh
, buf
, strlen(buf
));
1228 static void ssh_free_packet(struct Packet
*pkt
)
1233 static struct Packet
*ssh_new_packet(void)
1235 struct Packet
*pkt
= snew(struct Packet
);
1237 pkt
->body
= pkt
->data
= NULL
;
1239 pkt
->logmode
= PKTLOG_EMIT
;
1247 * Collect incoming data in the incoming packet buffer.
1248 * Decipher and verify the packet when it is completely read.
1249 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
1250 * Update the *data and *datalen variables.
1251 * Return a Packet structure when a packet is completed.
1253 static struct Packet
*ssh1_rdpkt(Ssh ssh
, unsigned char **data
, int *datalen
)
1255 struct rdpkt1_state_tag
*st
= &ssh
->rdpkt1_state
;
1257 crBegin(ssh
->ssh1_rdpkt_crstate
);
1259 st
->pktin
= ssh_new_packet();
1261 st
->pktin
->type
= 0;
1262 st
->pktin
->length
= 0;
1264 for (st
->i
= st
->len
= 0; st
->i
< 4; st
->i
++) {
1265 while ((*datalen
) == 0)
1267 st
->len
= (st
->len
<< 8) + **data
;
1268 (*data
)++, (*datalen
)--;
1271 st
->pad
= 8 - (st
->len
% 8);
1272 st
->biglen
= st
->len
+ st
->pad
;
1273 st
->pktin
->length
= st
->len
- 5;
1275 if (st
->biglen
< 0) {
1276 bombout(("Extremely large packet length from server suggests"
1277 " data stream corruption"));
1278 ssh_free_packet(st
->pktin
);
1282 st
->pktin
->maxlen
= st
->biglen
;
1283 st
->pktin
->data
= snewn(st
->biglen
+ APIEXTRA
, unsigned char);
1285 st
->to_read
= st
->biglen
;
1286 st
->p
= st
->pktin
->data
;
1287 while (st
->to_read
> 0) {
1288 st
->chunk
= st
->to_read
;
1289 while ((*datalen
) == 0)
1291 if (st
->chunk
> (*datalen
))
1292 st
->chunk
= (*datalen
);
1293 memcpy(st
->p
, *data
, st
->chunk
);
1295 *datalen
-= st
->chunk
;
1297 st
->to_read
-= st
->chunk
;
1300 if (ssh
->cipher
&& detect_attack(ssh
->crcda_ctx
, st
->pktin
->data
,
1301 st
->biglen
, NULL
)) {
1302 bombout(("Network attack (CRC compensation) detected!"));
1303 ssh_free_packet(st
->pktin
);
1308 ssh
->cipher
->decrypt(ssh
->v1_cipher_ctx
, st
->pktin
->data
, st
->biglen
);
1310 st
->realcrc
= crc32_compute(st
->pktin
->data
, st
->biglen
- 4);
1311 st
->gotcrc
= GET_32BIT(st
->pktin
->data
+ st
->biglen
- 4);
1312 if (st
->gotcrc
!= st
->realcrc
) {
1313 bombout(("Incorrect CRC received on packet"));
1314 ssh_free_packet(st
->pktin
);
1318 st
->pktin
->body
= st
->pktin
->data
+ st
->pad
+ 1;
1319 st
->pktin
->savedpos
= 0;
1321 if (ssh
->v1_compressing
) {
1322 unsigned char *decompblk
;
1324 if (!zlib_decompress_block(ssh
->sc_comp_ctx
,
1325 st
->pktin
->body
- 1, st
->pktin
->length
+ 1,
1326 &decompblk
, &decomplen
)) {
1327 bombout(("Zlib decompression encountered invalid data"));
1328 ssh_free_packet(st
->pktin
);
1332 if (st
->pktin
->maxlen
< st
->pad
+ decomplen
) {
1333 st
->pktin
->maxlen
= st
->pad
+ decomplen
;
1334 st
->pktin
->data
= sresize(st
->pktin
->data
,
1335 st
->pktin
->maxlen
+ APIEXTRA
,
1337 st
->pktin
->body
= st
->pktin
->data
+ st
->pad
+ 1;
1340 memcpy(st
->pktin
->body
- 1, decompblk
, decomplen
);
1342 st
->pktin
->length
= decomplen
- 1;
1345 st
->pktin
->type
= st
->pktin
->body
[-1];
1348 * Log incoming packet, possibly omitting sensitive fields.
1352 struct logblank_t blank
;
1353 if (ssh
->logomitdata
) {
1354 int do_blank
= FALSE
, blank_prefix
= 0;
1355 /* "Session data" packets - omit the data field */
1356 if ((st
->pktin
->type
== SSH1_SMSG_STDOUT_DATA
) ||
1357 (st
->pktin
->type
== SSH1_SMSG_STDERR_DATA
)) {
1358 do_blank
= TRUE
; blank_prefix
= 4;
1359 } else if (st
->pktin
->type
== SSH1_MSG_CHANNEL_DATA
) {
1360 do_blank
= TRUE
; blank_prefix
= 8;
1363 blank
.offset
= blank_prefix
;
1364 blank
.len
= st
->pktin
->length
;
1365 blank
.type
= PKTLOG_OMIT
;
1369 log_packet(ssh
->logctx
,
1370 PKT_INCOMING
, st
->pktin
->type
,
1371 ssh1_pkt_type(st
->pktin
->type
),
1372 st
->pktin
->body
, st
->pktin
->length
,
1373 nblanks
, &blank
, NULL
);
1376 crFinish(st
->pktin
);
1379 static struct Packet
*ssh2_rdpkt(Ssh ssh
, unsigned char **data
, int *datalen
)
1381 struct rdpkt2_state_tag
*st
= &ssh
->rdpkt2_state
;
1383 crBegin(ssh
->ssh2_rdpkt_crstate
);
1385 st
->pktin
= ssh_new_packet();
1387 st
->pktin
->type
= 0;
1388 st
->pktin
->length
= 0;
1390 st
->cipherblk
= ssh
->sccipher
->blksize
;
1393 if (st
->cipherblk
< 8)
1395 st
->maclen
= ssh
->scmac ? ssh
->scmac
->len
: 0;
1397 if (ssh
->sccipher
&& (ssh
->sccipher
->flags
& SSH_CIPHER_IS_CBC
) &&
1400 * When dealing with a CBC-mode cipher, we want to avoid the
1401 * possibility of an attacker's tweaking the ciphertext stream
1402 * so as to cause us to feed the same block to the block
1403 * cipher more than once and thus leak information
1404 * (VU#958563). The way we do this is not to take any
1405 * decisions on the basis of anything we've decrypted until
1406 * we've verified it with a MAC. That includes the packet
1407 * length, so we just read data and check the MAC repeatedly,
1408 * and when the MAC passes, see if the length we've got is
1412 /* May as well allocate the whole lot now. */
1413 st
->pktin
->data
= snewn(OUR_V2_PACKETLIMIT
+ st
->maclen
+ APIEXTRA
,
1416 /* Read an amount corresponding to the MAC. */
1417 for (st
->i
= 0; st
->i
< st
->maclen
; st
->i
++) {
1418 while ((*datalen
) == 0)
1420 st
->pktin
->data
[st
->i
] = *(*data
)++;
1426 unsigned char seq
[4];
1427 ssh
->scmac
->start(ssh
->sc_mac_ctx
);
1428 PUT_32BIT(seq
, st
->incoming_sequence
);
1429 ssh
->scmac
->bytes(ssh
->sc_mac_ctx
, seq
, 4);
1432 for (;;) { /* Once around this loop per cipher block. */
1433 /* Read another cipher-block's worth, and tack it onto the end. */
1434 for (st
->i
= 0; st
->i
< st
->cipherblk
; st
->i
++) {
1435 while ((*datalen
) == 0)
1437 st
->pktin
->data
[st
->packetlen
+st
->maclen
+st
->i
] = *(*data
)++;
1440 /* Decrypt one more block (a little further back in the stream). */
1441 ssh
->sccipher
->decrypt(ssh
->sc_cipher_ctx
,
1442 st
->pktin
->data
+ st
->packetlen
,
1444 /* Feed that block to the MAC. */
1445 ssh
->scmac
->bytes(ssh
->sc_mac_ctx
,
1446 st
->pktin
->data
+ st
->packetlen
, st
->cipherblk
);
1447 st
->packetlen
+= st
->cipherblk
;
1448 /* See if that gives us a valid packet. */
1449 if (ssh
->scmac
->verresult(ssh
->sc_mac_ctx
,
1450 st
->pktin
->data
+ st
->packetlen
) &&
1451 (st
->len
= GET_32BIT(st
->pktin
->data
)) + 4 == st
->packetlen
)
1453 if (st
->packetlen
>= OUR_V2_PACKETLIMIT
) {
1454 bombout(("No valid incoming packet found"));
1455 ssh_free_packet(st
->pktin
);
1459 st
->pktin
->maxlen
= st
->packetlen
+ st
->maclen
;
1460 st
->pktin
->data
= sresize(st
->pktin
->data
,
1461 st
->pktin
->maxlen
+ APIEXTRA
,
1464 st
->pktin
->data
= snewn(st
->cipherblk
+ APIEXTRA
, unsigned char);
1467 * Acquire and decrypt the first block of the packet. This will
1468 * contain the length and padding details.
1470 for (st
->i
= st
->len
= 0; st
->i
< st
->cipherblk
; st
->i
++) {
1471 while ((*datalen
) == 0)
1473 st
->pktin
->data
[st
->i
] = *(*data
)++;
1478 ssh
->sccipher
->decrypt(ssh
->sc_cipher_ctx
,
1479 st
->pktin
->data
, st
->cipherblk
);
1482 * Now get the length figure.
1484 st
->len
= GET_32BIT(st
->pktin
->data
);
1487 * _Completely_ silly lengths should be stomped on before they
1488 * do us any more damage.
1490 if (st
->len
< 0 || st
->len
> OUR_V2_PACKETLIMIT
||
1491 (st
->len
+ 4) % st
->cipherblk
!= 0) {
1492 bombout(("Incoming packet was garbled on decryption"));
1493 ssh_free_packet(st
->pktin
);
1498 * So now we can work out the total packet length.
1500 st
->packetlen
= st
->len
+ 4;
1503 * Allocate memory for the rest of the packet.
1505 st
->pktin
->maxlen
= st
->packetlen
+ st
->maclen
;
1506 st
->pktin
->data
= sresize(st
->pktin
->data
,
1507 st
->pktin
->maxlen
+ APIEXTRA
,
1511 * Read and decrypt the remainder of the packet.
1513 for (st
->i
= st
->cipherblk
; st
->i
< st
->packetlen
+ st
->maclen
;
1515 while ((*datalen
) == 0)
1517 st
->pktin
->data
[st
->i
] = *(*data
)++;
1520 /* Decrypt everything _except_ the MAC. */
1522 ssh
->sccipher
->decrypt(ssh
->sc_cipher_ctx
,
1523 st
->pktin
->data
+ st
->cipherblk
,
1524 st
->packetlen
- st
->cipherblk
);
1530 && !ssh
->scmac
->verify(ssh
->sc_mac_ctx
, st
->pktin
->data
,
1531 st
->len
+ 4, st
->incoming_sequence
)) {
1532 bombout(("Incorrect MAC received on packet"));
1533 ssh_free_packet(st
->pktin
);
1537 /* Get and sanity-check the amount of random padding. */
1538 st
->pad
= st
->pktin
->data
[4];
1539 if (st
->pad
< 4 || st
->len
- st
->pad
< 1) {
1540 bombout(("Invalid padding length on received packet"));
1541 ssh_free_packet(st
->pktin
);
1545 * This enables us to deduce the payload length.
1547 st
->payload
= st
->len
- st
->pad
- 1;
1549 st
->pktin
->length
= st
->payload
+ 5;
1550 st
->pktin
->encrypted_len
= st
->packetlen
;
1552 st
->pktin
->sequence
= st
->incoming_sequence
++;
1555 * Decompress packet payload.
1558 unsigned char *newpayload
;
1561 ssh
->sccomp
->decompress(ssh
->sc_comp_ctx
,
1562 st
->pktin
->data
+ 5, st
->pktin
->length
- 5,
1563 &newpayload
, &newlen
)) {
1564 if (st
->pktin
->maxlen
< newlen
+ 5) {
1565 st
->pktin
->maxlen
= newlen
+ 5;
1566 st
->pktin
->data
= sresize(st
->pktin
->data
,
1567 st
->pktin
->maxlen
+ APIEXTRA
,
1570 st
->pktin
->length
= 5 + newlen
;
1571 memcpy(st
->pktin
->data
+ 5, newpayload
, newlen
);
1576 st
->pktin
->savedpos
= 6;
1577 st
->pktin
->body
= st
->pktin
->data
;
1578 st
->pktin
->type
= st
->pktin
->data
[5];
1581 * Log incoming packet, possibly omitting sensitive fields.
1585 struct logblank_t blank
;
1586 if (ssh
->logomitdata
) {
1587 int do_blank
= FALSE
, blank_prefix
= 0;
1588 /* "Session data" packets - omit the data field */
1589 if (st
->pktin
->type
== SSH2_MSG_CHANNEL_DATA
) {
1590 do_blank
= TRUE
; blank_prefix
= 8;
1591 } else if (st
->pktin
->type
== SSH2_MSG_CHANNEL_EXTENDED_DATA
) {
1592 do_blank
= TRUE
; blank_prefix
= 12;
1595 blank
.offset
= blank_prefix
;
1596 blank
.len
= (st
->pktin
->length
-6) - blank_prefix
;
1597 blank
.type
= PKTLOG_OMIT
;
1601 log_packet(ssh
->logctx
, PKT_INCOMING
, st
->pktin
->type
,
1602 ssh2_pkt_type(ssh
->pkt_kctx
, ssh
->pkt_actx
,
1604 st
->pktin
->data
+6, st
->pktin
->length
-6,
1605 nblanks
, &blank
, &st
->pktin
->sequence
);
1608 crFinish(st
->pktin
);
1611 static int s_wrpkt_prepare(Ssh ssh
, struct Packet
*pkt
, int *offset_p
)
1613 int pad
, biglen
, i
, pktoffs
;
1617 * XXX various versions of SC (including 8.8.4) screw up the
1618 * register allocation in this function and use the same register
1619 * (D6) for len and as a temporary, with predictable results. The
1620 * following sledgehammer prevents this.
1627 log_packet(ssh
->logctx
, PKT_OUTGOING
, pkt
->data
[12],
1628 ssh1_pkt_type(pkt
->data
[12]),
1629 pkt
->body
, pkt
->length
- (pkt
->body
- pkt
->data
),
1630 pkt
->nblanks
, pkt
->blanks
, NULL
);
1631 sfree(pkt
->blanks
); pkt
->blanks
= NULL
;
1634 if (ssh
->v1_compressing
) {
1635 unsigned char *compblk
;
1637 zlib_compress_block(ssh
->cs_comp_ctx
,
1638 pkt
->data
+ 12, pkt
->length
- 12,
1639 &compblk
, &complen
);
1640 ssh_pkt_ensure(pkt
, complen
+ 2); /* just in case it's got bigger */
1641 memcpy(pkt
->data
+ 12, compblk
, complen
);
1643 pkt
->length
= complen
+ 12;
1646 ssh_pkt_ensure(pkt
, pkt
->length
+ 4); /* space for CRC */
1648 len
= pkt
->length
- 4 - 8; /* len(type+data+CRC) */
1649 pad
= 8 - (len
% 8);
1651 biglen
= len
+ pad
; /* len(padding+type+data+CRC) */
1653 for (i
= pktoffs
; i
< 4+8; i
++)
1654 pkt
->data
[i
] = random_byte();
1655 crc
= crc32_compute(pkt
->data
+ pktoffs
+ 4, biglen
- 4); /* all ex len */
1656 PUT_32BIT(pkt
->data
+ pktoffs
+ 4 + biglen
- 4, crc
);
1657 PUT_32BIT(pkt
->data
+ pktoffs
, len
);
1660 ssh
->cipher
->encrypt(ssh
->v1_cipher_ctx
,
1661 pkt
->data
+ pktoffs
+ 4, biglen
);
1663 if (offset_p
) *offset_p
= pktoffs
;
1664 return biglen
+ 4; /* len(length+padding+type+data+CRC) */
1667 static int s_write(Ssh ssh
, void *data
, int len
)
1670 log_packet(ssh
->logctx
, PKT_OUTGOING
, -1, NULL
, data
, len
,
1672 return sk_write(ssh
->s
, (char *)data
, len
);
1675 static void s_wrpkt(Ssh ssh
, struct Packet
*pkt
)
1677 int len
, backlog
, offset
;
1678 len
= s_wrpkt_prepare(ssh
, pkt
, &offset
);
1679 backlog
= s_write(ssh
, pkt
->data
+ offset
, len
);
1680 if (backlog
> SSH_MAX_BACKLOG
)
1681 ssh_throttle_all(ssh
, 1, backlog
);
1682 ssh_free_packet(pkt
);
1685 static void s_wrpkt_defer(Ssh ssh
, struct Packet
*pkt
)
1688 len
= s_wrpkt_prepare(ssh
, pkt
, &offset
);
1689 if (ssh
->deferred_len
+ len
> ssh
->deferred_size
) {
1690 ssh
->deferred_size
= ssh
->deferred_len
+ len
+ 128;
1691 ssh
->deferred_send_data
= sresize(ssh
->deferred_send_data
,
1695 memcpy(ssh
->deferred_send_data
+ ssh
->deferred_len
,
1696 pkt
->data
+ offset
, len
);
1697 ssh
->deferred_len
+= len
;
1698 ssh_free_packet(pkt
);
1702 * Construct a SSH-1 packet with the specified contents.
1703 * (This all-at-once interface used to be the only one, but now SSH-1
1704 * packets can also be constructed incrementally.)
1706 static struct Packet
*construct_packet(Ssh ssh
, int pkttype
, va_list ap
)
1712 pkt
= ssh1_pkt_init(pkttype
);
1714 while ((argtype
= va_arg(ap
, int)) != PKT_END
) {
1715 unsigned char *argp
, argchar
;
1717 unsigned long argint
;
1720 /* Actual fields in the packet */
1722 argint
= va_arg(ap
, int);
1723 ssh_pkt_adduint32(pkt
, argint
);
1726 argchar
= (unsigned char) va_arg(ap
, int);
1727 ssh_pkt_addbyte(pkt
, argchar
);
1730 argp
= va_arg(ap
, unsigned char *);
1731 arglen
= va_arg(ap
, int);
1732 ssh_pkt_adddata(pkt
, argp
, arglen
);
1735 sargp
= va_arg(ap
, char *);
1736 ssh_pkt_addstring(pkt
, sargp
);
1739 bn
= va_arg(ap
, Bignum
);
1740 ssh1_pkt_addmp(pkt
, bn
);
1742 /* Tokens for modifications to packet logging */
1744 dont_log_password(ssh
, pkt
, PKTLOG_BLANK
);
1747 dont_log_data(ssh
, pkt
, PKTLOG_OMIT
);
1750 end_log_omission(ssh
, pkt
);
1758 static void send_packet(Ssh ssh
, int pkttype
, ...)
1762 va_start(ap
, pkttype
);
1763 pkt
= construct_packet(ssh
, pkttype
, ap
);
1768 static void defer_packet(Ssh ssh
, int pkttype
, ...)
1772 va_start(ap
, pkttype
);
1773 pkt
= construct_packet(ssh
, pkttype
, ap
);
1775 s_wrpkt_defer(ssh
, pkt
);
1778 static int ssh_versioncmp(char *a
, char *b
)
1781 unsigned long av
, bv
;
1783 av
= strtoul(a
, &ae
, 10);
1784 bv
= strtoul(b
, &be
, 10);
1786 return (av
< bv ?
-1 : +1);
1791 av
= strtoul(ae
, &ae
, 10);
1792 bv
= strtoul(be
, &be
, 10);
1794 return (av
< bv ?
-1 : +1);
1799 * Utility routines for putting an SSH-protocol `string' and
1800 * `uint32' into a hash state.
1802 static void hash_string(const struct ssh_hash
*h
, void *s
, void *str
, int len
)
1804 unsigned char lenblk
[4];
1805 PUT_32BIT(lenblk
, len
);
1806 h
->bytes(s
, lenblk
, 4);
1807 h
->bytes(s
, str
, len
);
1810 static void hash_uint32(const struct ssh_hash
*h
, void *s
, unsigned i
)
1812 unsigned char intblk
[4];
1813 PUT_32BIT(intblk
, i
);
1814 h
->bytes(s
, intblk
, 4);
1818 * Packet construction functions. Mostly shared between SSH-1 and SSH-2.
1820 static void ssh_pkt_ensure(struct Packet
*pkt
, int length
)
1822 if (pkt
->maxlen
< length
) {
1823 unsigned char *body
= pkt
->body
;
1824 int offset
= body ? body
- pkt
->data
: 0;
1825 pkt
->maxlen
= length
+ 256;
1826 pkt
->data
= sresize(pkt
->data
, pkt
->maxlen
+ APIEXTRA
, unsigned char);
1827 if (body
) pkt
->body
= pkt
->data
+ offset
;
1830 static void ssh_pkt_adddata(struct Packet
*pkt
, void *data
, int len
)
1832 if (pkt
->logmode
!= PKTLOG_EMIT
) {
1834 pkt
->blanks
= sresize(pkt
->blanks
, pkt
->nblanks
, struct logblank_t
);
1836 pkt
->blanks
[pkt
->nblanks
-1].offset
= pkt
->length
-
1837 (pkt
->body
- pkt
->data
);
1838 pkt
->blanks
[pkt
->nblanks
-1].len
= len
;
1839 pkt
->blanks
[pkt
->nblanks
-1].type
= pkt
->logmode
;
1842 ssh_pkt_ensure(pkt
, pkt
->length
);
1843 memcpy(pkt
->data
+ pkt
->length
- len
, data
, len
);
1845 static void ssh_pkt_addbyte(struct Packet
*pkt
, unsigned char byte
)
1847 ssh_pkt_adddata(pkt
, &byte
, 1);
1849 static void ssh2_pkt_addbool(struct Packet
*pkt
, unsigned char value
)
1851 ssh_pkt_adddata(pkt
, &value
, 1);
1853 static void ssh_pkt_adduint32(struct Packet
*pkt
, unsigned long value
)
1856 PUT_32BIT(x
, value
);
1857 ssh_pkt_adddata(pkt
, x
, 4);
1859 static void ssh_pkt_addstring_start(struct Packet
*pkt
)
1861 ssh_pkt_adduint32(pkt
, 0);
1862 pkt
->savedpos
= pkt
->length
;
1864 static void ssh_pkt_addstring_str(struct Packet
*pkt
, char *data
)
1866 ssh_pkt_adddata(pkt
, data
, strlen(data
));
1867 PUT_32BIT(pkt
->data
+ pkt
->savedpos
- 4, pkt
->length
- pkt
->savedpos
);
1869 static void ssh_pkt_addstring_data(struct Packet
*pkt
, char *data
, int len
)
1871 ssh_pkt_adddata(pkt
, data
, len
);
1872 PUT_32BIT(pkt
->data
+ pkt
->savedpos
- 4, pkt
->length
- pkt
->savedpos
);
1874 static void ssh_pkt_addstring(struct Packet
*pkt
, char *data
)
1876 ssh_pkt_addstring_start(pkt
);
1877 ssh_pkt_addstring_str(pkt
, data
);
1879 static void ssh1_pkt_addmp(struct Packet
*pkt
, Bignum b
)
1881 int len
= ssh1_bignum_length(b
);
1882 unsigned char *data
= snewn(len
, unsigned char);
1883 (void) ssh1_write_bignum(data
, b
);
1884 ssh_pkt_adddata(pkt
, data
, len
);
1887 static unsigned char *ssh2_mpint_fmt(Bignum b
, int *len
)
1890 int i
, n
= (bignum_bitcount(b
) + 7) / 8;
1891 p
= snewn(n
+ 1, unsigned char);
1893 for (i
= 1; i
<= n
; i
++)
1894 p
[i
] = bignum_byte(b
, n
- i
);
1896 while (i
<= n
&& p
[i
] == 0 && (p
[i
+ 1] & 0x80) == 0)
1898 memmove(p
, p
+ i
, n
+ 1 - i
);
1902 static void ssh2_pkt_addmp(struct Packet
*pkt
, Bignum b
)
1906 p
= ssh2_mpint_fmt(b
, &len
);
1907 ssh_pkt_addstring_start(pkt
);
1908 ssh_pkt_addstring_data(pkt
, (char *)p
, len
);
1912 static struct Packet
*ssh1_pkt_init(int pkt_type
)
1914 struct Packet
*pkt
= ssh_new_packet();
1915 pkt
->length
= 4 + 8; /* space for length + max padding */
1916 ssh_pkt_addbyte(pkt
, pkt_type
);
1917 pkt
->body
= pkt
->data
+ pkt
->length
;
1921 /* For legacy code (SSH-1 and -2 packet construction used to be separate) */
1922 #define ssh2_pkt_ensure(pkt, length) ssh_pkt_ensure(pkt, length)
1923 #define ssh2_pkt_adddata(pkt, data, len) ssh_pkt_adddata(pkt, data, len)
1924 #define ssh2_pkt_addbyte(pkt, byte) ssh_pkt_addbyte(pkt, byte)
1925 #define ssh2_pkt_adduint32(pkt, value) ssh_pkt_adduint32(pkt, value)
1926 #define ssh2_pkt_addstring_start(pkt) ssh_pkt_addstring_start(pkt)
1927 #define ssh2_pkt_addstring_str(pkt, data) ssh_pkt_addstring_str(pkt, data)
1928 #define ssh2_pkt_addstring_data(pkt, data, len) ssh_pkt_addstring_data(pkt, data, len)
1929 #define ssh2_pkt_addstring(pkt, data) ssh_pkt_addstring(pkt, data)
1931 static struct Packet
*ssh2_pkt_init(int pkt_type
)
1933 struct Packet
*pkt
= ssh_new_packet();
1934 pkt
->length
= 5; /* space for packet length + padding length */
1936 ssh_pkt_addbyte(pkt
, (unsigned char) pkt_type
);
1937 pkt
->body
= pkt
->data
+ pkt
->length
; /* after packet type */
1942 * Construct an SSH-2 final-form packet: compress it, encrypt it,
1943 * put the MAC on it. Final packet, ready to be sent, is stored in
1944 * pkt->data. Total length is returned.
1946 static int ssh2_pkt_construct(Ssh ssh
, struct Packet
*pkt
)
1948 int cipherblk
, maclen
, padding
, i
;
1951 log_packet(ssh
->logctx
, PKT_OUTGOING
, pkt
->data
[5],
1952 ssh2_pkt_type(ssh
->pkt_kctx
, ssh
->pkt_actx
, pkt
->data
[5]),
1953 pkt
->body
, pkt
->length
- (pkt
->body
- pkt
->data
),
1954 pkt
->nblanks
, pkt
->blanks
, &ssh
->v2_outgoing_sequence
);
1955 sfree(pkt
->blanks
); pkt
->blanks
= NULL
;
1959 * Compress packet payload.
1962 unsigned char *newpayload
;
1965 ssh
->cscomp
->compress(ssh
->cs_comp_ctx
, pkt
->data
+ 5,
1967 &newpayload
, &newlen
)) {
1969 ssh2_pkt_adddata(pkt
, newpayload
, newlen
);
1975 * Add padding. At least four bytes, and must also bring total
1976 * length (minus MAC) up to a multiple of the block size.
1977 * If pkt->forcepad is set, make sure the packet is at least that size
1980 cipherblk
= ssh
->cscipher ? ssh
->cscipher
->blksize
: 8; /* block size */
1981 cipherblk
= cipherblk
< 8 ?
8 : cipherblk
; /* or 8 if blksize < 8 */
1983 if (pkt
->length
+ padding
< pkt
->forcepad
)
1984 padding
= pkt
->forcepad
- pkt
->length
;
1986 (cipherblk
- (pkt
->length
+ padding
) % cipherblk
) % cipherblk
;
1987 assert(padding
<= 255);
1988 maclen
= ssh
->csmac ? ssh
->csmac
->len
: 0;
1989 ssh2_pkt_ensure(pkt
, pkt
->length
+ padding
+ maclen
);
1990 pkt
->data
[4] = padding
;
1991 for (i
= 0; i
< padding
; i
++)
1992 pkt
->data
[pkt
->length
+ i
] = random_byte();
1993 PUT_32BIT(pkt
->data
, pkt
->length
+ padding
- 4);
1995 ssh
->csmac
->generate(ssh
->cs_mac_ctx
, pkt
->data
,
1996 pkt
->length
+ padding
,
1997 ssh
->v2_outgoing_sequence
);
1998 ssh
->v2_outgoing_sequence
++; /* whether or not we MACed */
2001 ssh
->cscipher
->encrypt(ssh
->cs_cipher_ctx
,
2002 pkt
->data
, pkt
->length
+ padding
);
2004 pkt
->encrypted_len
= pkt
->length
+ padding
;
2006 /* Ready-to-send packet starts at pkt->data. We return length. */
2007 return pkt
->length
+ padding
+ maclen
;
2011 * Routines called from the main SSH code to send packets. There
2012 * are quite a few of these, because we have two separate
2013 * mechanisms for delaying the sending of packets:
2015 * - In order to send an IGNORE message and a password message in
2016 * a single fixed-length blob, we require the ability to
2017 * concatenate the encrypted forms of those two packets _into_ a
2018 * single blob and then pass it to our <network.h> transport
2019 * layer in one go. Hence, there's a deferment mechanism which
2020 * works after packet encryption.
2022 * - In order to avoid sending any connection-layer messages
2023 * during repeat key exchange, we have to queue up any such
2024 * outgoing messages _before_ they are encrypted (and in
2025 * particular before they're allocated sequence numbers), and
2026 * then send them once we've finished.
2028 * I call these mechanisms `defer' and `queue' respectively, so as
2029 * to distinguish them reasonably easily.
2031 * The functions send_noqueue() and defer_noqueue() free the packet
2032 * structure they are passed. Every outgoing packet goes through
2033 * precisely one of these functions in its life; packets passed to
2034 * ssh2_pkt_send() or ssh2_pkt_defer() either go straight to one of
2035 * these or get queued, and then when the queue is later emptied
2036 * the packets are all passed to defer_noqueue().
2038 * When using a CBC-mode cipher, it's necessary to ensure that an
2039 * attacker can't provide data to be encrypted using an IV that they
2040 * know. We ensure this by prefixing each packet that might contain
2041 * user data with an SSH_MSG_IGNORE. This is done using the deferral
2042 * mechanism, so in this case send_noqueue() ends up redirecting to
2043 * defer_noqueue(). If you don't like this inefficiency, don't use
2047 static void ssh2_pkt_defer_noqueue(Ssh
, struct Packet
*, int);
2048 static void ssh_pkt_defersend(Ssh
);
2051 * Send an SSH-2 packet immediately, without queuing or deferring.
2053 static void ssh2_pkt_send_noqueue(Ssh ssh
, struct Packet
*pkt
)
2057 if (ssh
->cscipher
!= NULL
&& (ssh
->cscipher
->flags
& SSH_CIPHER_IS_CBC
)) {
2058 /* We need to send two packets, so use the deferral mechanism. */
2059 ssh2_pkt_defer_noqueue(ssh
, pkt
, FALSE
);
2060 ssh_pkt_defersend(ssh
);
2063 len
= ssh2_pkt_construct(ssh
, pkt
);
2064 backlog
= s_write(ssh
, pkt
->data
, len
);
2065 if (backlog
> SSH_MAX_BACKLOG
)
2066 ssh_throttle_all(ssh
, 1, backlog
);
2068 ssh
->outgoing_data_size
+= pkt
->encrypted_len
;
2069 if (!ssh
->kex_in_progress
&&
2070 ssh
->max_data_size
!= 0 &&
2071 ssh
->outgoing_data_size
> ssh
->max_data_size
)
2072 do_ssh2_transport(ssh
, "too much data sent", -1, NULL
);
2074 ssh_free_packet(pkt
);
2078 * Defer an SSH-2 packet.
2080 static void ssh2_pkt_defer_noqueue(Ssh ssh
, struct Packet
*pkt
, int noignore
)
2083 if (ssh
->cscipher
!= NULL
&& (ssh
->cscipher
->flags
& SSH_CIPHER_IS_CBC
) &&
2084 ssh
->deferred_len
== 0 && !noignore
&&
2085 !(ssh
->remote_bugs
& BUG_CHOKES_ON_SSH2_IGNORE
)) {
2087 * Interpose an SSH_MSG_IGNORE to ensure that user data don't
2088 * get encrypted with a known IV.
2090 struct Packet
*ipkt
= ssh2_pkt_init(SSH2_MSG_IGNORE
);
2091 ssh2_pkt_addstring_start(ipkt
);
2092 ssh2_pkt_defer_noqueue(ssh
, ipkt
, TRUE
);
2094 len
= ssh2_pkt_construct(ssh
, pkt
);
2095 if (ssh
->deferred_len
+ len
> ssh
->deferred_size
) {
2096 ssh
->deferred_size
= ssh
->deferred_len
+ len
+ 128;
2097 ssh
->deferred_send_data
= sresize(ssh
->deferred_send_data
,
2101 memcpy(ssh
->deferred_send_data
+ ssh
->deferred_len
, pkt
->data
, len
);
2102 ssh
->deferred_len
+= len
;
2103 ssh
->deferred_data_size
+= pkt
->encrypted_len
;
2104 ssh_free_packet(pkt
);
2108 * Queue an SSH-2 packet.
2110 static void ssh2_pkt_queue(Ssh ssh
, struct Packet
*pkt
)
2112 assert(ssh
->queueing
);
2114 if (ssh
->queuelen
>= ssh
->queuesize
) {
2115 ssh
->queuesize
= ssh
->queuelen
+ 32;
2116 ssh
->queue
= sresize(ssh
->queue
, ssh
->queuesize
, struct Packet
*);
2119 ssh
->queue
[ssh
->queuelen
++] = pkt
;
2123 * Either queue or send a packet, depending on whether queueing is
2126 static void ssh2_pkt_send(Ssh ssh
, struct Packet
*pkt
)
2129 ssh2_pkt_queue(ssh
, pkt
);
2131 ssh2_pkt_send_noqueue(ssh
, pkt
);
2135 * Either queue or defer a packet, depending on whether queueing is
2138 static void ssh2_pkt_defer(Ssh ssh
, struct Packet
*pkt
)
2141 ssh2_pkt_queue(ssh
, pkt
);
2143 ssh2_pkt_defer_noqueue(ssh
, pkt
, FALSE
);
2147 * Send the whole deferred data block constructed by
2148 * ssh2_pkt_defer() or SSH-1's defer_packet().
2150 * The expected use of the defer mechanism is that you call
2151 * ssh2_pkt_defer() a few times, then call ssh_pkt_defersend(). If
2152 * not currently queueing, this simply sets up deferred_send_data
2153 * and then sends it. If we _are_ currently queueing, the calls to
2154 * ssh2_pkt_defer() put the deferred packets on to the queue
2155 * instead, and therefore ssh_pkt_defersend() has no deferred data
2156 * to send. Hence, there's no need to make it conditional on
2159 static void ssh_pkt_defersend(Ssh ssh
)
2162 backlog
= s_write(ssh
, ssh
->deferred_send_data
, ssh
->deferred_len
);
2163 ssh
->deferred_len
= ssh
->deferred_size
= 0;
2164 sfree(ssh
->deferred_send_data
);
2165 ssh
->deferred_send_data
= NULL
;
2166 if (backlog
> SSH_MAX_BACKLOG
)
2167 ssh_throttle_all(ssh
, 1, backlog
);
2169 ssh
->outgoing_data_size
+= ssh
->deferred_data_size
;
2170 if (!ssh
->kex_in_progress
&&
2171 ssh
->max_data_size
!= 0 &&
2172 ssh
->outgoing_data_size
> ssh
->max_data_size
)
2173 do_ssh2_transport(ssh
, "too much data sent", -1, NULL
);
2174 ssh
->deferred_data_size
= 0;
2178 * Send a packet whose length needs to be disguised (typically
2179 * passwords or keyboard-interactive responses).
2181 static void ssh2_pkt_send_with_padding(Ssh ssh
, struct Packet
*pkt
,
2187 * The simplest way to do this is to adjust the
2188 * variable-length padding field in the outgoing packet.
2190 * Currently compiled out, because some Cisco SSH servers
2191 * don't like excessively padded packets (bah, why's it
2194 pkt
->forcepad
= padsize
;
2195 ssh2_pkt_send(ssh
, pkt
);
2200 * If we can't do that, however, an alternative approach is
2201 * to use the pkt_defer mechanism to bundle the packet
2202 * tightly together with an SSH_MSG_IGNORE such that their
2203 * combined length is a constant. So first we construct the
2204 * final form of this packet and defer its sending.
2206 ssh2_pkt_defer(ssh
, pkt
);
2209 * Now construct an SSH_MSG_IGNORE which includes a string
2210 * that's an exact multiple of the cipher block size. (If
2211 * the cipher is NULL so that the block size is
2212 * unavailable, we don't do this trick at all, because we
2213 * gain nothing by it.)
2215 if (ssh
->cscipher
&&
2216 !(ssh
->remote_bugs
& BUG_CHOKES_ON_SSH2_IGNORE
)) {
2219 stringlen
= (256 - ssh
->deferred_len
);
2220 stringlen
+= ssh
->cscipher
->blksize
- 1;
2221 stringlen
-= (stringlen
% ssh
->cscipher
->blksize
);
2224 * Temporarily disable actual compression, so we
2225 * can guarantee to get this string exactly the
2226 * length we want it. The compression-disabling
2227 * routine should return an integer indicating how
2228 * many bytes we should adjust our string length
2232 ssh
->cscomp
->disable_compression(ssh
->cs_comp_ctx
);
2234 pkt
= ssh2_pkt_init(SSH2_MSG_IGNORE
);
2235 ssh2_pkt_addstring_start(pkt
);
2236 for (i
= 0; i
< stringlen
; i
++) {
2237 char c
= (char) random_byte();
2238 ssh2_pkt_addstring_data(pkt
, &c
, 1);
2240 ssh2_pkt_defer(ssh
, pkt
);
2242 ssh_pkt_defersend(ssh
);
2247 * Send all queued SSH-2 packets. We send them by means of
2248 * ssh2_pkt_defer_noqueue(), in case they included a pair of
2249 * packets that needed to be lumped together.
2251 static void ssh2_pkt_queuesend(Ssh ssh
)
2255 assert(!ssh
->queueing
);
2257 for (i
= 0; i
< ssh
->queuelen
; i
++)
2258 ssh2_pkt_defer_noqueue(ssh
, ssh
->queue
[i
], FALSE
);
2261 ssh_pkt_defersend(ssh
);
2265 void bndebug(char *string
, Bignum b
)
2269 p
= ssh2_mpint_fmt(b
, &len
);
2270 debug(("%s", string
));
2271 for (i
= 0; i
< len
; i
++)
2272 debug((" %02x", p
[i
]));
2278 static void hash_mpint(const struct ssh_hash
*h
, void *s
, Bignum b
)
2282 p
= ssh2_mpint_fmt(b
, &len
);
2283 hash_string(h
, s
, p
, len
);
2288 * Packet decode functions for both SSH-1 and SSH-2.
2290 static unsigned long ssh_pkt_getuint32(struct Packet
*pkt
)
2292 unsigned long value
;
2293 if (pkt
->length
- pkt
->savedpos
< 4)
2294 return 0; /* arrgh, no way to decline (FIXME?) */
2295 value
= GET_32BIT(pkt
->body
+ pkt
->savedpos
);
2299 static int ssh2_pkt_getbool(struct Packet
*pkt
)
2301 unsigned long value
;
2302 if (pkt
->length
- pkt
->savedpos
< 1)
2303 return 0; /* arrgh, no way to decline (FIXME?) */
2304 value
= pkt
->body
[pkt
->savedpos
] != 0;
2308 static void ssh_pkt_getstring(struct Packet
*pkt
, char **p
, int *length
)
2313 if (pkt
->length
- pkt
->savedpos
< 4)
2315 len
= GET_32BIT(pkt
->body
+ pkt
->savedpos
);
2320 if (pkt
->length
- pkt
->savedpos
< *length
)
2322 *p
= (char *)(pkt
->body
+ pkt
->savedpos
);
2323 pkt
->savedpos
+= *length
;
2325 static void *ssh_pkt_getdata(struct Packet
*pkt
, int length
)
2327 if (pkt
->length
- pkt
->savedpos
< length
)
2329 pkt
->savedpos
+= length
;
2330 return pkt
->body
+ (pkt
->savedpos
- length
);
2332 static int ssh1_pkt_getrsakey(struct Packet
*pkt
, struct RSAKey
*key
,
2333 unsigned char **keystr
)
2337 j
= makekey(pkt
->body
+ pkt
->savedpos
,
2338 pkt
->length
- pkt
->savedpos
,
2345 assert(pkt
->savedpos
< pkt
->length
);
2349 static Bignum
ssh1_pkt_getmp(struct Packet
*pkt
)
2354 j
= ssh1_read_bignum(pkt
->body
+ pkt
->savedpos
,
2355 pkt
->length
- pkt
->savedpos
, &b
);
2363 static Bignum
ssh2_pkt_getmp(struct Packet
*pkt
)
2369 ssh_pkt_getstring(pkt
, &p
, &length
);
2374 b
= bignum_from_bytes((unsigned char *)p
, length
);
2379 * Helper function to add an SSH-2 signature blob to a packet.
2380 * Expects to be shown the public key blob as well as the signature
2381 * blob. Normally works just like ssh2_pkt_addstring, but will
2382 * fiddle with the signature packet if necessary for
2383 * BUG_SSH2_RSA_PADDING.
2385 static void ssh2_add_sigblob(Ssh ssh
, struct Packet
*pkt
,
2386 void *pkblob_v
, int pkblob_len
,
2387 void *sigblob_v
, int sigblob_len
)
2389 unsigned char *pkblob
= (unsigned char *)pkblob_v
;
2390 unsigned char *sigblob
= (unsigned char *)sigblob_v
;
2392 /* dmemdump(pkblob, pkblob_len); */
2393 /* dmemdump(sigblob, sigblob_len); */
2396 * See if this is in fact an ssh-rsa signature and a buggy
2397 * server; otherwise we can just do this the easy way.
2399 if ((ssh
->remote_bugs
& BUG_SSH2_RSA_PADDING
) &&
2400 (GET_32BIT(pkblob
) == 7 && !memcmp(pkblob
+4, "ssh-rsa", 7))) {
2401 int pos
, len
, siglen
;
2404 * Find the byte length of the modulus.
2407 pos
= 4+7; /* skip over "ssh-rsa" */
2408 pos
+= 4 + GET_32BIT(pkblob
+pos
); /* skip over exponent */
2409 len
= GET_32BIT(pkblob
+pos
); /* find length of modulus */
2410 pos
+= 4; /* find modulus itself */
2411 while (len
> 0 && pkblob
[pos
] == 0)
2413 /* debug(("modulus length is %d\n", len)); */
2416 * Now find the signature integer.
2418 pos
= 4+7; /* skip over "ssh-rsa" */
2419 siglen
= GET_32BIT(sigblob
+pos
);
2420 /* debug(("signature length is %d\n", siglen)); */
2422 if (len
!= siglen
) {
2423 unsigned char newlen
[4];
2424 ssh2_pkt_addstring_start(pkt
);
2425 ssh2_pkt_addstring_data(pkt
, (char *)sigblob
, pos
);
2426 /* dmemdump(sigblob, pos); */
2427 pos
+= 4; /* point to start of actual sig */
2428 PUT_32BIT(newlen
, len
);
2429 ssh2_pkt_addstring_data(pkt
, (char *)newlen
, 4);
2430 /* dmemdump(newlen, 4); */
2432 while (len
-- > siglen
) {
2433 ssh2_pkt_addstring_data(pkt
, (char *)newlen
, 1);
2434 /* dmemdump(newlen, 1); */
2436 ssh2_pkt_addstring_data(pkt
, (char *)(sigblob
+pos
), siglen
);
2437 /* dmemdump(sigblob+pos, siglen); */
2441 /* Otherwise fall through and do it the easy way. */
2444 ssh2_pkt_addstring_start(pkt
);
2445 ssh2_pkt_addstring_data(pkt
, (char *)sigblob
, sigblob_len
);
2449 * Examine the remote side's version string and compare it against
2450 * a list of known buggy implementations.
2452 static void ssh_detect_bugs(Ssh ssh
, char *vstring
)
2454 char *imp
; /* pointer to implementation part */
2456 imp
+= strcspn(imp
, "-");
2458 imp
+= strcspn(imp
, "-");
2461 ssh
->remote_bugs
= 0;
2464 * General notes on server version strings:
2465 * - Not all servers reporting "Cisco-1.25" have all the bugs listed
2466 * here -- in particular, we've heard of one that's perfectly happy
2467 * with SSH1_MSG_IGNOREs -- but this string never seems to change,
2468 * so we can't distinguish them.
2470 if (conf_get_int(ssh
->conf
, CONF_sshbug_ignore1
) == FORCE_ON
||
2471 (conf_get_int(ssh
->conf
, CONF_sshbug_ignore1
) == AUTO
&&
2472 (!strcmp(imp
, "1.2.18") || !strcmp(imp
, "1.2.19") ||
2473 !strcmp(imp
, "1.2.20") || !strcmp(imp
, "1.2.21") ||
2474 !strcmp(imp
, "1.2.22") || !strcmp(imp
, "Cisco-1.25") ||
2475 !strcmp(imp
, "OSU_1.4alpha3") || !strcmp(imp
, "OSU_1.5alpha4")))) {
2477 * These versions don't support SSH1_MSG_IGNORE, so we have
2478 * to use a different defence against password length
2481 ssh
->remote_bugs
|= BUG_CHOKES_ON_SSH1_IGNORE
;
2482 logevent("We believe remote version has SSH-1 ignore bug");
2485 if (conf_get_int(ssh
->conf
, CONF_sshbug_plainpw1
) == FORCE_ON
||
2486 (conf_get_int(ssh
->conf
, CONF_sshbug_plainpw1
) == AUTO
&&
2487 (!strcmp(imp
, "Cisco-1.25") || !strcmp(imp
, "OSU_1.4alpha3")))) {
2489 * These versions need a plain password sent; they can't
2490 * handle having a null and a random length of data after
2493 ssh
->remote_bugs
|= BUG_NEEDS_SSH1_PLAIN_PASSWORD
;
2494 logevent("We believe remote version needs a plain SSH-1 password");
2497 if (conf_get_int(ssh
->conf
, CONF_sshbug_rsa1
) == FORCE_ON
||
2498 (conf_get_int(ssh
->conf
, CONF_sshbug_rsa1
) == AUTO
&&
2499 (!strcmp(imp
, "Cisco-1.25")))) {
2501 * These versions apparently have no clue whatever about
2502 * RSA authentication and will panic and die if they see
2503 * an AUTH_RSA message.
2505 ssh
->remote_bugs
|= BUG_CHOKES_ON_RSA
;
2506 logevent("We believe remote version can't handle SSH-1 RSA authentication");
2509 if (conf_get_int(ssh
->conf
, CONF_sshbug_hmac2
) == FORCE_ON
||
2510 (conf_get_int(ssh
->conf
, CONF_sshbug_hmac2
) == AUTO
&&
2511 !wc_match("* VShell", imp
) &&
2512 (wc_match("2.1.0*", imp
) || wc_match("2.0.*", imp
) ||
2513 wc_match("2.2.0*", imp
) || wc_match("2.3.0*", imp
) ||
2514 wc_match("2.1 *", imp
)))) {
2516 * These versions have the HMAC bug.
2518 ssh
->remote_bugs
|= BUG_SSH2_HMAC
;
2519 logevent("We believe remote version has SSH-2 HMAC bug");
2522 if (conf_get_int(ssh
->conf
, CONF_sshbug_derivekey2
) == FORCE_ON
||
2523 (conf_get_int(ssh
->conf
, CONF_sshbug_derivekey2
) == AUTO
&&
2524 !wc_match("* VShell", imp
) &&
2525 (wc_match("2.0.0*", imp
) || wc_match("2.0.10*", imp
) ))) {
2527 * These versions have the key-derivation bug (failing to
2528 * include the literal shared secret in the hashes that
2529 * generate the keys).
2531 ssh
->remote_bugs
|= BUG_SSH2_DERIVEKEY
;
2532 logevent("We believe remote version has SSH-2 key-derivation bug");
2535 if (conf_get_int(ssh
->conf
, CONF_sshbug_rsapad2
) == FORCE_ON
||
2536 (conf_get_int(ssh
->conf
, CONF_sshbug_rsapad2
) == AUTO
&&
2537 (wc_match("OpenSSH_2.[5-9]*", imp
) ||
2538 wc_match("OpenSSH_3.[0-2]*", imp
)))) {
2540 * These versions have the SSH-2 RSA padding bug.
2542 ssh
->remote_bugs
|= BUG_SSH2_RSA_PADDING
;
2543 logevent("We believe remote version has SSH-2 RSA padding bug");
2546 if (conf_get_int(ssh
->conf
, CONF_sshbug_pksessid2
) == FORCE_ON
||
2547 (conf_get_int(ssh
->conf
, CONF_sshbug_pksessid2
) == AUTO
&&
2548 wc_match("OpenSSH_2.[0-2]*", imp
))) {
2550 * These versions have the SSH-2 session-ID bug in
2551 * public-key authentication.
2553 ssh
->remote_bugs
|= BUG_SSH2_PK_SESSIONID
;
2554 logevent("We believe remote version has SSH-2 public-key-session-ID bug");
2557 if (conf_get_int(ssh
->conf
, CONF_sshbug_rekey2
) == FORCE_ON
||
2558 (conf_get_int(ssh
->conf
, CONF_sshbug_rekey2
) == AUTO
&&
2559 (wc_match("DigiSSH_2.0", imp
) ||
2560 wc_match("OpenSSH_2.[0-4]*", imp
) ||
2561 wc_match("OpenSSH_2.5.[0-3]*", imp
) ||
2562 wc_match("Sun_SSH_1.0", imp
) ||
2563 wc_match("Sun_SSH_1.0.1", imp
) ||
2564 /* All versions <= 1.2.6 (they changed their format in 1.2.7) */
2565 wc_match("WeOnlyDo-*", imp
)))) {
2567 * These versions have the SSH-2 rekey bug.
2569 ssh
->remote_bugs
|= BUG_SSH2_REKEY
;
2570 logevent("We believe remote version has SSH-2 rekey bug");
2573 if (conf_get_int(ssh
->conf
, CONF_sshbug_maxpkt2
) == FORCE_ON
||
2574 (conf_get_int(ssh
->conf
, CONF_sshbug_maxpkt2
) == AUTO
&&
2575 (wc_match("1.36_sshlib GlobalSCAPE", imp
) ||
2576 wc_match("1.36 sshlib: GlobalScape", imp
)))) {
2578 * This version ignores our makpkt and needs to be throttled.
2580 ssh
->remote_bugs
|= BUG_SSH2_MAXPKT
;
2581 logevent("We believe remote version ignores SSH-2 maximum packet size");
2584 if (conf_get_int(ssh
->conf
, CONF_sshbug_ignore2
) == FORCE_ON
) {
2586 * Servers that don't support SSH2_MSG_IGNORE. Currently,
2587 * none detected automatically.
2589 ssh
->remote_bugs
|= BUG_CHOKES_ON_SSH2_IGNORE
;
2590 logevent("We believe remote version has SSH-2 ignore bug");
2593 if (conf_get_int(ssh
->conf
, CONF_sshbug_winadj
) == FORCE_ON
) {
2595 * Servers that don't support our winadj request for one
2596 * reason or another. Currently, none detected automatically.
2598 ssh
->remote_bugs
|= BUG_CHOKES_ON_WINADJ
;
2599 logevent("We believe remote version has winadj bug");
2604 * The `software version' part of an SSH version string is required
2605 * to contain no spaces or minus signs.
2607 static void ssh_fix_verstring(char *str
)
2609 /* Eat "SSH-<protoversion>-". */
2610 assert(*str
== 'S'); str
++;
2611 assert(*str
== 'S'); str
++;
2612 assert(*str
== 'H'); str
++;
2613 assert(*str
== '-'); str
++;
2614 while (*str
&& *str
!= '-') str
++;
2615 assert(*str
== '-'); str
++;
2617 /* Convert minus signs and spaces in the remaining string into
2620 if (*str
== '-' || *str
== ' ')
2627 * Send an appropriate SSH version string.
2629 static void ssh_send_verstring(Ssh ssh
, char *svers
)
2633 if (ssh
->version
== 2) {
2635 * Construct a v2 version string.
2637 verstring
= dupprintf("SSH-2.0-%s\015\012", sshver
);
2640 * Construct a v1 version string.
2642 verstring
= dupprintf("SSH-%s-%s\012",
2643 (ssh_versioncmp(svers
, "1.5") <= 0 ?
2648 ssh_fix_verstring(verstring
);
2650 if (ssh
->version
== 2) {
2653 * Record our version string.
2655 len
= strcspn(verstring
, "\015\012");
2656 ssh
->v_c
= snewn(len
+ 1, char);
2657 memcpy(ssh
->v_c
, verstring
, len
);
2661 logeventf(ssh
, "We claim version: %.*s",
2662 strcspn(verstring
, "\015\012"), verstring
);
2663 s_write(ssh
, verstring
, strlen(verstring
));
2667 static int do_ssh_init(Ssh ssh
, unsigned char c
)
2669 struct do_ssh_init_state
{
2678 crState(do_ssh_init_state
);
2682 /* Search for a line beginning with the string "SSH-" in the input. */
2684 if (c
!= 'S') goto no
;
2686 if (c
!= 'S') goto no
;
2688 if (c
!= 'H') goto no
;
2690 if (c
!= '-') goto no
;
2699 s
->vstring
= snewn(s
->vstrsize
, char);
2700 strcpy(s
->vstring
, "SSH-");
2704 crReturn(1); /* get another char */
2705 if (s
->vslen
>= s
->vstrsize
- 1) {
2707 s
->vstring
= sresize(s
->vstring
, s
->vstrsize
, char);
2709 s
->vstring
[s
->vslen
++] = c
;
2712 s
->version
[s
->i
] = '\0';
2714 } else if (s
->i
< sizeof(s
->version
) - 1)
2715 s
->version
[s
->i
++] = c
;
2716 } else if (c
== '\012')
2720 ssh
->agentfwd_enabled
= FALSE
;
2721 ssh
->rdpkt2_state
.incoming_sequence
= 0;
2723 s
->vstring
[s
->vslen
] = 0;
2724 s
->vstring
[strcspn(s
->vstring
, "\015\012")] = '\0';/* remove EOL chars */
2725 logeventf(ssh
, "Server version: %s", s
->vstring
);
2726 ssh_detect_bugs(ssh
, s
->vstring
);
2729 * Decide which SSH protocol version to support.
2732 /* Anything strictly below "2.0" means protocol 1 is supported. */
2733 s
->proto1
= ssh_versioncmp(s
->version
, "2.0") < 0;
2734 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
2735 s
->proto2
= ssh_versioncmp(s
->version
, "1.99") >= 0;
2737 if (conf_get_int(ssh
->conf
, CONF_sshprot
) == 0 && !s
->proto1
) {
2738 bombout(("SSH protocol version 1 required by user but not provided by server"));
2741 if (conf_get_int(ssh
->conf
, CONF_sshprot
) == 3 && !s
->proto2
) {
2742 bombout(("SSH protocol version 2 required by user but not provided by server"));
2746 if (s
->proto2
&& (conf_get_int(ssh
->conf
, CONF_sshprot
) >= 2 || !s
->proto1
))
2751 logeventf(ssh
, "Using SSH protocol version %d", ssh
->version
);
2753 /* Send the version string, if we haven't already */
2754 if (conf_get_int(ssh
->conf
, CONF_sshprot
) != 3)
2755 ssh_send_verstring(ssh
, s
->version
);
2757 if (ssh
->version
== 2) {
2760 * Record their version string.
2762 len
= strcspn(s
->vstring
, "\015\012");
2763 ssh
->v_s
= snewn(len
+ 1, char);
2764 memcpy(ssh
->v_s
, s
->vstring
, len
);
2768 * Initialise SSH-2 protocol.
2770 ssh
->protocol
= ssh2_protocol
;
2771 ssh2_protocol_setup(ssh
);
2772 ssh
->s_rdpkt
= ssh2_rdpkt
;
2775 * Initialise SSH-1 protocol.
2777 ssh
->protocol
= ssh1_protocol
;
2778 ssh1_protocol_setup(ssh
);
2779 ssh
->s_rdpkt
= ssh1_rdpkt
;
2781 if (ssh
->version
== 2)
2782 do_ssh2_transport(ssh
, NULL
, -1, NULL
);
2784 update_specials_menu(ssh
->frontend
);
2785 ssh
->state
= SSH_STATE_BEFORE_SIZE
;
2786 ssh
->pinger
= pinger_new(ssh
->conf
, &ssh_backend
, ssh
);
2793 static void ssh_process_incoming_data(Ssh ssh
,
2794 unsigned char **data
, int *datalen
)
2796 struct Packet
*pktin
;
2798 pktin
= ssh
->s_rdpkt(ssh
, data
, datalen
);
2800 ssh
->protocol(ssh
, NULL
, 0, pktin
);
2801 ssh_free_packet(pktin
);
2805 static void ssh_queue_incoming_data(Ssh ssh
,
2806 unsigned char **data
, int *datalen
)
2808 bufchain_add(&ssh
->queued_incoming_data
, *data
, *datalen
);
2813 static void ssh_process_queued_incoming_data(Ssh ssh
)
2816 unsigned char *data
;
2819 while (!ssh
->frozen
&& bufchain_size(&ssh
->queued_incoming_data
)) {
2820 bufchain_prefix(&ssh
->queued_incoming_data
, &vdata
, &len
);
2824 while (!ssh
->frozen
&& len
> 0)
2825 ssh_process_incoming_data(ssh
, &data
, &len
);
2828 bufchain_consume(&ssh
->queued_incoming_data
, origlen
- len
);
2832 static void ssh_set_frozen(Ssh ssh
, int frozen
)
2835 sk_set_frozen(ssh
->s
, frozen
);
2836 ssh
->frozen
= frozen
;
2839 static void ssh_gotdata(Ssh ssh
, unsigned char *data
, int datalen
)
2841 /* Log raw data, if we're in that mode. */
2843 log_packet(ssh
->logctx
, PKT_INCOMING
, -1, NULL
, data
, datalen
,
2846 crBegin(ssh
->ssh_gotdata_crstate
);
2849 * To begin with, feed the characters one by one to the
2850 * protocol initialisation / selection function do_ssh_init().
2851 * When that returns 0, we're done with the initial greeting
2852 * exchange and can move on to packet discipline.
2855 int ret
; /* need not be kept across crReturn */
2857 crReturnV
; /* more data please */
2858 ret
= do_ssh_init(ssh
, *data
);
2866 * We emerge from that loop when the initial negotiation is
2867 * over and we have selected an s_rdpkt function. Now pass
2868 * everything to s_rdpkt, and then pass the resulting packets
2869 * to the proper protocol handler.
2873 while (bufchain_size(&ssh
->queued_incoming_data
) > 0 || datalen
> 0) {
2875 ssh_queue_incoming_data(ssh
, &data
, &datalen
);
2876 /* This uses up all data and cannot cause anything interesting
2877 * to happen; indeed, for anything to happen at all, we must
2878 * return, so break out. */
2880 } else if (bufchain_size(&ssh
->queued_incoming_data
) > 0) {
2881 /* This uses up some or all data, and may freeze the
2883 ssh_process_queued_incoming_data(ssh
);
2885 /* This uses up some or all data, and may freeze the
2887 ssh_process_incoming_data(ssh
, &data
, &datalen
);
2889 /* FIXME this is probably EBW. */
2890 if (ssh
->state
== SSH_STATE_CLOSED
)
2893 /* We're out of data. Go and get some more. */
2899 static int ssh_do_close(Ssh ssh
, int notify_exit
)
2902 struct ssh_channel
*c
;
2904 ssh
->state
= SSH_STATE_CLOSED
;
2905 expire_timer_context(ssh
);
2910 notify_remote_exit(ssh
->frontend
);
2915 * Now we must shut down any port- and X-forwarded channels going
2916 * through this connection.
2918 if (ssh
->channels
) {
2919 while (NULL
!= (c
= index234(ssh
->channels
, 0))) {
2922 x11_close(c
->u
.x11
.s
);
2925 case CHAN_SOCKDATA_DORMANT
:
2926 pfd_close(c
->u
.pfd
.s
);
2929 del234(ssh
->channels
, c
); /* moving next one to index 0 */
2930 if (ssh
->version
== 2)
2931 bufchain_clear(&c
->v
.v2
.outbuffer
);
2936 * Go through port-forwardings, and close any associated
2937 * listening sockets.
2939 if (ssh
->portfwds
) {
2940 struct ssh_portfwd
*pf
;
2941 while (NULL
!= (pf
= index234(ssh
->portfwds
, 0))) {
2942 /* Dispose of any listening socket. */
2944 pfd_terminate(pf
->local
);
2945 del234(ssh
->portfwds
, pf
); /* moving next one to index 0 */
2948 freetree234(ssh
->portfwds
);
2949 ssh
->portfwds
= NULL
;
2955 static void ssh_log(Plug plug
, int type
, SockAddr addr
, int port
,
2956 const char *error_msg
, int error_code
)
2958 Ssh ssh
= (Ssh
) plug
;
2959 char addrbuf
[256], *msg
;
2961 sk_getaddr(addr
, addrbuf
, lenof(addrbuf
));
2964 msg
= dupprintf("Connecting to %s port %d", addrbuf
, port
);
2966 msg
= dupprintf("Failed to connect to %s: %s", addrbuf
, error_msg
);
2972 static int ssh_closing(Plug plug
, const char *error_msg
, int error_code
,
2975 Ssh ssh
= (Ssh
) plug
;
2976 int need_notify
= ssh_do_close(ssh
, FALSE
);
2979 if (!ssh
->close_expected
)
2980 error_msg
= "Server unexpectedly closed network connection";
2982 error_msg
= "Server closed network connection";
2985 if (ssh
->close_expected
&& ssh
->clean_exit
&& ssh
->exitcode
< 0)
2989 notify_remote_exit(ssh
->frontend
);
2992 logevent(error_msg
);
2993 if (!ssh
->close_expected
|| !ssh
->clean_exit
)
2994 connection_fatal(ssh
->frontend
, "%s", error_msg
);
2998 static int ssh_receive(Plug plug
, int urgent
, char *data
, int len
)
3000 Ssh ssh
= (Ssh
) plug
;
3001 ssh_gotdata(ssh
, (unsigned char *)data
, len
);
3002 if (ssh
->state
== SSH_STATE_CLOSED
) {
3003 ssh_do_close(ssh
, TRUE
);
3009 static void ssh_sent(Plug plug
, int bufsize
)
3011 Ssh ssh
= (Ssh
) plug
;
3013 * If the send backlog on the SSH socket itself clears, we
3014 * should unthrottle the whole world if it was throttled.
3016 if (bufsize
< SSH_MAX_BACKLOG
)
3017 ssh_throttle_all(ssh
, 0, bufsize
);
3021 * Connect to specified host and port.
3022 * Returns an error message, or NULL on success.
3023 * Also places the canonical host name into `realhost'. It must be
3024 * freed by the caller.
3026 static const char *connect_to_host(Ssh ssh
, char *host
, int port
,
3027 char **realhost
, int nodelay
, int keepalive
)
3029 static const struct plug_function_table fn_table
= {
3040 int addressfamily
, sshprot
;
3042 loghost
= conf_get_str(ssh
->conf
, CONF_loghost
);
3046 ssh
->savedhost
= dupstr(loghost
);
3047 ssh
->savedport
= 22; /* default ssh port */
3050 * A colon suffix on savedhost also lets us affect
3053 * (FIXME: do something about IPv6 address literals here.)
3055 colon
= strrchr(ssh
->savedhost
, ':');
3059 ssh
->savedport
= atoi(colon
);
3062 ssh
->savedhost
= dupstr(host
);
3064 port
= 22; /* default ssh port */
3065 ssh
->savedport
= port
;
3071 addressfamily
= conf_get_int(ssh
->conf
, CONF_addressfamily
);
3072 logeventf(ssh
, "Looking up host \"%s\"%s", host
,
3073 (addressfamily
== ADDRTYPE_IPV4 ?
" (IPv4)" :
3074 (addressfamily
== ADDRTYPE_IPV6 ?
" (IPv6)" : "")));
3075 addr
= name_lookup(host
, port
, realhost
, ssh
->conf
, addressfamily
);
3076 if ((err
= sk_addr_error(addr
)) != NULL
) {
3080 ssh
->fullhostname
= dupstr(*realhost
); /* save in case of GSSAPI */
3085 ssh
->fn
= &fn_table
;
3086 ssh
->s
= new_connection(addr
, *realhost
, port
,
3087 0, 1, nodelay
, keepalive
, (Plug
) ssh
, ssh
->conf
);
3088 if ((err
= sk_socket_error(ssh
->s
)) != NULL
) {
3090 notify_remote_exit(ssh
->frontend
);
3095 * If the SSH version number's fixed, set it now, and if it's SSH-2,
3096 * send the version string too.
3098 sshprot
= conf_get_int(ssh
->conf
, CONF_sshprot
);
3103 ssh_send_verstring(ssh
, NULL
);
3107 * loghost, if configured, overrides realhost.
3111 *realhost
= dupstr(loghost
);
3118 * Throttle or unthrottle the SSH connection.
3120 static void ssh_throttle_conn(Ssh ssh
, int adjust
)
3122 int old_count
= ssh
->conn_throttle_count
;
3123 ssh
->conn_throttle_count
+= adjust
;
3124 assert(ssh
->conn_throttle_count
>= 0);
3125 if (ssh
->conn_throttle_count
&& !old_count
) {
3126 ssh_set_frozen(ssh
, 1);
3127 } else if (!ssh
->conn_throttle_count
&& old_count
) {
3128 ssh_set_frozen(ssh
, 0);
3133 * Throttle or unthrottle _all_ local data streams (for when sends
3134 * on the SSH connection itself back up).
3136 static void ssh_throttle_all(Ssh ssh
, int enable
, int bufsize
)
3139 struct ssh_channel
*c
;
3141 if (enable
== ssh
->throttled_all
)
3143 ssh
->throttled_all
= enable
;
3144 ssh
->overall_bufsize
= bufsize
;
3147 for (i
= 0; NULL
!= (c
= index234(ssh
->channels
, i
)); i
++) {
3149 case CHAN_MAINSESSION
:
3151 * This is treated separately, outside the switch.
3155 x11_override_throttle(c
->u
.x11
.s
, enable
);
3158 /* Agent channels require no buffer management. */
3161 pfd_override_throttle(c
->u
.pfd
.s
, enable
);
3167 static void ssh_agent_callback(void *sshv
, void *reply
, int replylen
)
3169 Ssh ssh
= (Ssh
) sshv
;
3171 ssh
->agent_response
= reply
;
3172 ssh
->agent_response_len
= replylen
;
3174 if (ssh
->version
== 1)
3175 do_ssh1_login(ssh
, NULL
, -1, NULL
);
3177 do_ssh2_authconn(ssh
, NULL
, -1, NULL
);
3180 static void ssh_dialog_callback(void *sshv
, int ret
)
3182 Ssh ssh
= (Ssh
) sshv
;
3184 ssh
->user_response
= ret
;
3186 if (ssh
->version
== 1)
3187 do_ssh1_login(ssh
, NULL
, -1, NULL
);
3189 do_ssh2_transport(ssh
, NULL
, -1, NULL
);
3192 * This may have unfrozen the SSH connection, so do a
3195 ssh_process_queued_incoming_data(ssh
);
3198 static void ssh_agentf_callback(void *cv
, void *reply
, int replylen
)
3200 struct ssh_channel
*c
= (struct ssh_channel
*)cv
;
3202 void *sentreply
= reply
;
3205 /* Fake SSH_AGENT_FAILURE. */
3206 sentreply
= "\0\0\0\1\5";
3209 if (ssh
->version
== 2) {
3210 ssh2_add_channel_data(c
, sentreply
, replylen
);
3213 send_packet(ssh
, SSH1_MSG_CHANNEL_DATA
,
3214 PKT_INT
, c
->remoteid
,
3217 PKT_DATA
, sentreply
, replylen
,
3226 * Client-initiated disconnection. Send a DISCONNECT if `wire_reason'
3227 * non-NULL, otherwise just close the connection. `client_reason' == NULL
3228 * => log `wire_reason'.
3230 static void ssh_disconnect(Ssh ssh
, char *client_reason
, char *wire_reason
,
3231 int code
, int clean_exit
)
3235 client_reason
= wire_reason
;
3237 error
= dupprintf("Disconnected: %s", client_reason
);
3239 error
= dupstr("Disconnected");
3241 if (ssh
->version
== 1) {
3242 send_packet(ssh
, SSH1_MSG_DISCONNECT
, PKT_STR
, wire_reason
,
3244 } else if (ssh
->version
== 2) {
3245 struct Packet
*pktout
= ssh2_pkt_init(SSH2_MSG_DISCONNECT
);
3246 ssh2_pkt_adduint32(pktout
, code
);
3247 ssh2_pkt_addstring(pktout
, wire_reason
);
3248 ssh2_pkt_addstring(pktout
, "en"); /* language tag */
3249 ssh2_pkt_send_noqueue(ssh
, pktout
);
3252 ssh
->close_expected
= TRUE
;
3253 ssh
->clean_exit
= clean_exit
;
3254 ssh_closing((Plug
)ssh
, error
, 0, 0);
3259 * Handle the key exchange and user authentication phases.
3261 static int do_ssh1_login(Ssh ssh
, unsigned char *in
, int inlen
,
3262 struct Packet
*pktin
)
3265 unsigned char cookie
[8], *ptr
;
3266 struct RSAKey servkey
, hostkey
;
3267 struct MD5Context md5c
;
3268 struct do_ssh1_login_state
{
3271 unsigned char *rsabuf
, *keystr1
, *keystr2
;
3272 unsigned long supported_ciphers_mask
, supported_auths_mask
;
3273 int tried_publickey
, tried_agent
;
3274 int tis_auth_refused
, ccard_auth_refused
;
3275 unsigned char session_id
[16];
3277 void *publickey_blob
;
3278 int publickey_bloblen
;
3279 char *publickey_comment
;
3280 int publickey_encrypted
;
3281 prompts_t
*cur_prompt
;
3284 unsigned char request
[5], *response
, *p
;
3295 crState(do_ssh1_login_state
);
3302 if (pktin
->type
!= SSH1_SMSG_PUBLIC_KEY
) {
3303 bombout(("Public key packet not received"));
3307 logevent("Received public keys");
3309 ptr
= ssh_pkt_getdata(pktin
, 8);
3311 bombout(("SSH-1 public key packet stopped before random cookie"));
3314 memcpy(cookie
, ptr
, 8);
3316 if (!ssh1_pkt_getrsakey(pktin
, &servkey
, &s
->keystr1
) ||
3317 !ssh1_pkt_getrsakey(pktin
, &hostkey
, &s
->keystr2
)) {
3318 bombout(("Failed to read SSH-1 public keys from public key packet"));
3323 * Log the host key fingerprint.
3327 logevent("Host key fingerprint is:");
3328 strcpy(logmsg
, " ");
3329 hostkey
.comment
= NULL
;
3330 rsa_fingerprint(logmsg
+ strlen(logmsg
),
3331 sizeof(logmsg
) - strlen(logmsg
), &hostkey
);
3335 ssh
->v1_remote_protoflags
= ssh_pkt_getuint32(pktin
);
3336 s
->supported_ciphers_mask
= ssh_pkt_getuint32(pktin
);
3337 s
->supported_auths_mask
= ssh_pkt_getuint32(pktin
);
3338 if ((ssh
->remote_bugs
& BUG_CHOKES_ON_RSA
))
3339 s
->supported_auths_mask
&= ~(1 << SSH1_AUTH_RSA
);
3341 ssh
->v1_local_protoflags
=
3342 ssh
->v1_remote_protoflags
& SSH1_PROTOFLAGS_SUPPORTED
;
3343 ssh
->v1_local_protoflags
|= SSH1_PROTOFLAG_SCREEN_NUMBER
;
3346 MD5Update(&md5c
, s
->keystr2
, hostkey
.bytes
);
3347 MD5Update(&md5c
, s
->keystr1
, servkey
.bytes
);
3348 MD5Update(&md5c
, cookie
, 8);
3349 MD5Final(s
->session_id
, &md5c
);
3351 for (i
= 0; i
< 32; i
++)
3352 ssh
->session_key
[i
] = random_byte();
3355 * Verify that the `bits' and `bytes' parameters match.
3357 if (hostkey
.bits
> hostkey
.bytes
* 8 ||
3358 servkey
.bits
> servkey
.bytes
* 8) {
3359 bombout(("SSH-1 public keys were badly formatted"));
3363 s
->len
= (hostkey
.bytes
> servkey
.bytes ? hostkey
.bytes
: servkey
.bytes
);
3365 s
->rsabuf
= snewn(s
->len
, unsigned char);
3368 * Verify the host key.
3372 * First format the key into a string.
3374 int len
= rsastr_len(&hostkey
);
3375 char fingerprint
[100];
3376 char *keystr
= snewn(len
, char);
3377 rsastr_fmt(keystr
, &hostkey
);
3378 rsa_fingerprint(fingerprint
, sizeof(fingerprint
), &hostkey
);
3380 ssh_set_frozen(ssh
, 1);
3381 s
->dlgret
= verify_ssh_host_key(ssh
->frontend
,
3382 ssh
->savedhost
, ssh
->savedport
,
3383 "rsa", keystr
, fingerprint
,
3384 ssh_dialog_callback
, ssh
);
3386 if (s
->dlgret
< 0) {
3390 bombout(("Unexpected data from server while waiting"
3391 " for user host key response"));
3394 } while (pktin
|| inlen
> 0);
3395 s
->dlgret
= ssh
->user_response
;
3397 ssh_set_frozen(ssh
, 0);
3399 if (s
->dlgret
== 0) {
3400 ssh_disconnect(ssh
, "User aborted at host key verification",
3406 for (i
= 0; i
< 32; i
++) {
3407 s
->rsabuf
[i
] = ssh
->session_key
[i
];
3409 s
->rsabuf
[i
] ^= s
->session_id
[i
];
3412 if (hostkey
.bytes
> servkey
.bytes
) {
3413 ret
= rsaencrypt(s
->rsabuf
, 32, &servkey
);
3415 ret
= rsaencrypt(s
->rsabuf
, servkey
.bytes
, &hostkey
);
3417 ret
= rsaencrypt(s
->rsabuf
, 32, &hostkey
);
3419 ret
= rsaencrypt(s
->rsabuf
, hostkey
.bytes
, &servkey
);
3422 bombout(("SSH-1 public key encryptions failed due to bad formatting"));
3426 logevent("Encrypted session key");
3429 int cipher_chosen
= 0, warn
= 0;
3430 char *cipher_string
= NULL
;
3432 for (i
= 0; !cipher_chosen
&& i
< CIPHER_MAX
; i
++) {
3433 int next_cipher
= conf_get_int_int(ssh
->conf
,
3434 CONF_ssh_cipherlist
, i
);
3435 if (next_cipher
== CIPHER_WARN
) {
3436 /* If/when we choose a cipher, warn about it */
3438 } else if (next_cipher
== CIPHER_AES
) {
3439 /* XXX Probably don't need to mention this. */
3440 logevent("AES not supported in SSH-1, skipping");
3442 switch (next_cipher
) {
3443 case CIPHER_3DES
: s
->cipher_type
= SSH_CIPHER_3DES
;
3444 cipher_string
= "3DES"; break;
3445 case CIPHER_BLOWFISH
: s
->cipher_type
= SSH_CIPHER_BLOWFISH
;
3446 cipher_string
= "Blowfish"; break;
3447 case CIPHER_DES
: s
->cipher_type
= SSH_CIPHER_DES
;
3448 cipher_string
= "single-DES"; break;
3450 if (s
->supported_ciphers_mask
& (1 << s
->cipher_type
))
3454 if (!cipher_chosen
) {
3455 if ((s
->supported_ciphers_mask
& (1 << SSH_CIPHER_3DES
)) == 0)
3456 bombout(("Server violates SSH-1 protocol by not "
3457 "supporting 3DES encryption"));
3459 /* shouldn't happen */
3460 bombout(("No supported ciphers found"));
3464 /* Warn about chosen cipher if necessary. */
3466 ssh_set_frozen(ssh
, 1);
3467 s
->dlgret
= askalg(ssh
->frontend
, "cipher", cipher_string
,
3468 ssh_dialog_callback
, ssh
);
3469 if (s
->dlgret
< 0) {
3473 bombout(("Unexpected data from server while waiting"
3474 " for user response"));
3477 } while (pktin
|| inlen
> 0);
3478 s
->dlgret
= ssh
->user_response
;
3480 ssh_set_frozen(ssh
, 0);
3481 if (s
->dlgret
== 0) {
3482 ssh_disconnect(ssh
, "User aborted at cipher warning", NULL
,
3489 switch (s
->cipher_type
) {
3490 case SSH_CIPHER_3DES
:
3491 logevent("Using 3DES encryption");
3493 case SSH_CIPHER_DES
:
3494 logevent("Using single-DES encryption");
3496 case SSH_CIPHER_BLOWFISH
:
3497 logevent("Using Blowfish encryption");
3501 send_packet(ssh
, SSH1_CMSG_SESSION_KEY
,
3502 PKT_CHAR
, s
->cipher_type
,
3503 PKT_DATA
, cookie
, 8,
3504 PKT_CHAR
, (s
->len
* 8) >> 8, PKT_CHAR
, (s
->len
* 8) & 0xFF,
3505 PKT_DATA
, s
->rsabuf
, s
->len
,
3506 PKT_INT
, ssh
->v1_local_protoflags
, PKT_END
);
3508 logevent("Trying to enable encryption...");
3512 ssh
->cipher
= (s
->cipher_type
== SSH_CIPHER_BLOWFISH ?
&ssh_blowfish_ssh1
:
3513 s
->cipher_type
== SSH_CIPHER_DES ?
&ssh_des
:
3515 ssh
->v1_cipher_ctx
= ssh
->cipher
->make_context();
3516 ssh
->cipher
->sesskey(ssh
->v1_cipher_ctx
, ssh
->session_key
);
3517 logeventf(ssh
, "Initialised %s encryption", ssh
->cipher
->text_name
);
3519 ssh
->crcda_ctx
= crcda_make_context();
3520 logevent("Installing CRC compensation attack detector");
3522 if (servkey
.modulus
) {
3523 sfree(servkey
.modulus
);
3524 servkey
.modulus
= NULL
;
3526 if (servkey
.exponent
) {
3527 sfree(servkey
.exponent
);
3528 servkey
.exponent
= NULL
;
3530 if (hostkey
.modulus
) {
3531 sfree(hostkey
.modulus
);
3532 hostkey
.modulus
= NULL
;
3534 if (hostkey
.exponent
) {
3535 sfree(hostkey
.exponent
);
3536 hostkey
.exponent
= NULL
;
3540 if (pktin
->type
!= SSH1_SMSG_SUCCESS
) {
3541 bombout(("Encryption not successfully enabled"));
3545 logevent("Successfully started encryption");
3547 fflush(stdout
); /* FIXME eh? */
3549 if ((ssh
->username
= get_remote_username(ssh
->conf
)) == NULL
) {
3550 int ret
; /* need not be kept over crReturn */
3551 s
->cur_prompt
= new_prompts(ssh
->frontend
);
3552 s
->cur_prompt
->to_server
= TRUE
;
3553 s
->cur_prompt
->name
= dupstr("SSH login name");
3554 add_prompt(s
->cur_prompt
, dupstr("login as: "), TRUE
);
3555 ret
= get_userpass_input(s
->cur_prompt
, NULL
, 0);
3558 crWaitUntil(!pktin
);
3559 ret
= get_userpass_input(s
->cur_prompt
, in
, inlen
);
3564 * Failed to get a username. Terminate.
3566 free_prompts(s
->cur_prompt
);
3567 ssh_disconnect(ssh
, "No username provided", NULL
, 0, TRUE
);
3570 ssh
->username
= dupstr(s
->cur_prompt
->prompts
[0]->result
);
3571 free_prompts(s
->cur_prompt
);
3574 send_packet(ssh
, SSH1_CMSG_USER
, PKT_STR
, ssh
->username
, PKT_END
);
3576 char *userlog
= dupprintf("Sent username \"%s\"", ssh
->username
);
3578 if (flags
& FLAG_INTERACTIVE
&&
3579 (!((flags
& FLAG_STDERR
) && (flags
& FLAG_VERBOSE
)))) {
3580 c_write_str(ssh
, userlog
);
3581 c_write_str(ssh
, "\r\n");
3589 if ((s
->supported_auths_mask
& (1 << SSH1_AUTH_RSA
)) == 0) {
3590 /* We must not attempt PK auth. Pretend we've already tried it. */
3591 s
->tried_publickey
= s
->tried_agent
= 1;
3593 s
->tried_publickey
= s
->tried_agent
= 0;
3595 s
->tis_auth_refused
= s
->ccard_auth_refused
= 0;
3597 * Load the public half of any configured keyfile for later use.
3599 s
->keyfile
= conf_get_filename(ssh
->conf
, CONF_keyfile
);
3600 if (!filename_is_null(s
->keyfile
)) {
3602 logeventf(ssh
, "Reading private key file \"%.150s\"",
3603 filename_to_str(s
->keyfile
));
3604 keytype
= key_type(s
->keyfile
);
3605 if (keytype
== SSH_KEYTYPE_SSH1
) {
3607 if (rsakey_pubblob(s
->keyfile
,
3608 &s
->publickey_blob
, &s
->publickey_bloblen
,
3609 &s
->publickey_comment
, &error
)) {
3610 s
->publickey_encrypted
= rsakey_encrypted(s
->keyfile
,
3614 logeventf(ssh
, "Unable to load private key (%s)", error
);
3615 msgbuf
= dupprintf("Unable to load private key file "
3616 "\"%.150s\" (%s)\r\n",
3617 filename_to_str(s
->keyfile
),
3619 c_write_str(ssh
, msgbuf
);
3621 s
->publickey_blob
= NULL
;
3625 logeventf(ssh
, "Unable to use this key file (%s)",
3626 key_type_to_str(keytype
));
3627 msgbuf
= dupprintf("Unable to use key file \"%.150s\""
3629 filename_to_str(s
->keyfile
),
3630 key_type_to_str(keytype
));
3631 c_write_str(ssh
, msgbuf
);
3633 s
->publickey_blob
= NULL
;
3636 s
->publickey_blob
= NULL
;
3638 while (pktin
->type
== SSH1_SMSG_FAILURE
) {
3639 s
->pwpkt_type
= SSH1_CMSG_AUTH_PASSWORD
;
3641 if (conf_get_int(ssh
->conf
, CONF_tryagent
) && agent_exists() && !s
->tried_agent
) {
3643 * Attempt RSA authentication using Pageant.
3649 logevent("Pageant is running. Requesting keys.");
3651 /* Request the keys held by the agent. */
3652 PUT_32BIT(s
->request
, 1);
3653 s
->request
[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES
;
3654 if (!agent_query(s
->request
, 5, &r
, &s
->responselen
,
3655 ssh_agent_callback
, ssh
)) {
3659 bombout(("Unexpected data from server while waiting"
3660 " for agent response"));
3663 } while (pktin
|| inlen
> 0);
3664 r
= ssh
->agent_response
;
3665 s
->responselen
= ssh
->agent_response_len
;
3667 s
->response
= (unsigned char *) r
;
3668 if (s
->response
&& s
->responselen
>= 5 &&
3669 s
->response
[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER
) {
3670 s
->p
= s
->response
+ 5;
3671 s
->nkeys
= GET_32BIT(s
->p
);
3673 logeventf(ssh
, "Pageant has %d SSH-1 keys", s
->nkeys
);
3674 for (s
->keyi
= 0; s
->keyi
< s
->nkeys
; s
->keyi
++) {
3675 unsigned char *pkblob
= s
->p
;
3679 do { /* do while (0) to make breaking easy */
3680 n
= ssh1_read_bignum
3681 (s
->p
, s
->responselen
-(s
->p
-s
->response
),
3686 n
= ssh1_read_bignum
3687 (s
->p
, s
->responselen
-(s
->p
-s
->response
),
3692 if (s
->responselen
- (s
->p
-s
->response
) < 4)
3694 s
->commentlen
= GET_32BIT(s
->p
);
3696 if (s
->responselen
- (s
->p
-s
->response
) <
3699 s
->commentp
= (char *)s
->p
;
3700 s
->p
+= s
->commentlen
;
3704 logevent("Pageant key list packet was truncated");
3708 if (s
->publickey_blob
) {
3709 if (!memcmp(pkblob
, s
->publickey_blob
,
3710 s
->publickey_bloblen
)) {
3711 logeventf(ssh
, "Pageant key #%d matches "
3712 "configured key file", s
->keyi
);
3713 s
->tried_publickey
= 1;
3715 /* Skip non-configured key */
3718 logeventf(ssh
, "Trying Pageant key #%d", s
->keyi
);
3719 send_packet(ssh
, SSH1_CMSG_AUTH_RSA
,
3720 PKT_BIGNUM
, s
->key
.modulus
, PKT_END
);
3722 if (pktin
->type
!= SSH1_SMSG_AUTH_RSA_CHALLENGE
) {
3723 logevent("Key refused");
3726 logevent("Received RSA challenge");
3727 if ((s
->challenge
= ssh1_pkt_getmp(pktin
)) == NULL
) {
3728 bombout(("Server's RSA challenge was badly formatted"));
3733 char *agentreq
, *q
, *ret
;
3736 len
= 1 + 4; /* message type, bit count */
3737 len
+= ssh1_bignum_length(s
->key
.exponent
);
3738 len
+= ssh1_bignum_length(s
->key
.modulus
);
3739 len
+= ssh1_bignum_length(s
->challenge
);
3740 len
+= 16; /* session id */
3741 len
+= 4; /* response format */
3742 agentreq
= snewn(4 + len
, char);
3743 PUT_32BIT(agentreq
, len
);
3745 *q
++ = SSH1_AGENTC_RSA_CHALLENGE
;
3746 PUT_32BIT(q
, bignum_bitcount(s
->key
.modulus
));
3748 q
+= ssh1_write_bignum(q
, s
->key
.exponent
);
3749 q
+= ssh1_write_bignum(q
, s
->key
.modulus
);
3750 q
+= ssh1_write_bignum(q
, s
->challenge
);
3751 memcpy(q
, s
->session_id
, 16);
3753 PUT_32BIT(q
, 1); /* response format */
3754 if (!agent_query(agentreq
, len
+ 4, &vret
, &retlen
,
3755 ssh_agent_callback
, ssh
)) {
3760 bombout(("Unexpected data from server"
3761 " while waiting for agent"
3765 } while (pktin
|| inlen
> 0);
3766 vret
= ssh
->agent_response
;
3767 retlen
= ssh
->agent_response_len
;
3772 if (ret
[4] == SSH1_AGENT_RSA_RESPONSE
) {
3773 logevent("Sending Pageant's response");
3774 send_packet(ssh
, SSH1_CMSG_AUTH_RSA_RESPONSE
,
3775 PKT_DATA
, ret
+ 5, 16,
3779 if (pktin
->type
== SSH1_SMSG_SUCCESS
) {
3781 ("Pageant's response accepted");
3782 if (flags
& FLAG_VERBOSE
) {
3783 c_write_str(ssh
, "Authenticated using"
3785 c_write(ssh
, s
->commentp
,
3787 c_write_str(ssh
, "\" from agent\r\n");
3792 ("Pageant's response not accepted");
3795 ("Pageant failed to answer challenge");
3799 logevent("No reply received from Pageant");
3802 freebn(s
->key
.exponent
);
3803 freebn(s
->key
.modulus
);
3804 freebn(s
->challenge
);
3809 if (s
->publickey_blob
&& !s
->tried_publickey
)
3810 logevent("Configured key file not in Pageant");
3812 logevent("Failed to get reply from Pageant");
3817 if (s
->publickey_blob
&& !s
->tried_publickey
) {
3819 * Try public key authentication with the specified
3822 int got_passphrase
; /* need not be kept over crReturn */
3823 if (flags
& FLAG_VERBOSE
)
3824 c_write_str(ssh
, "Trying public key authentication.\r\n");
3825 s
->keyfile
= conf_get_filename(ssh
->conf
, CONF_keyfile
);
3826 logeventf(ssh
, "Trying public key \"%s\"",
3827 filename_to_str(s
->keyfile
));
3828 s
->tried_publickey
= 1;
3829 got_passphrase
= FALSE
;
3830 while (!got_passphrase
) {
3832 * Get a passphrase, if necessary.
3834 char *passphrase
= NULL
; /* only written after crReturn */
3836 if (!s
->publickey_encrypted
) {
3837 if (flags
& FLAG_VERBOSE
)
3838 c_write_str(ssh
, "No passphrase required.\r\n");
3841 int ret
; /* need not be kept over crReturn */
3842 s
->cur_prompt
= new_prompts(ssh
->frontend
);
3843 s
->cur_prompt
->to_server
= FALSE
;
3844 s
->cur_prompt
->name
= dupstr("SSH key passphrase");
3845 add_prompt(s
->cur_prompt
,
3846 dupprintf("Passphrase for key \"%.100s\": ",
3847 s
->publickey_comment
), FALSE
);
3848 ret
= get_userpass_input(s
->cur_prompt
, NULL
, 0);
3851 crWaitUntil(!pktin
);
3852 ret
= get_userpass_input(s
->cur_prompt
, in
, inlen
);
3856 /* Failed to get a passphrase. Terminate. */
3857 free_prompts(s
->cur_prompt
);
3858 ssh_disconnect(ssh
, NULL
, "Unable to authenticate",
3862 passphrase
= dupstr(s
->cur_prompt
->prompts
[0]->result
);
3863 free_prompts(s
->cur_prompt
);
3866 * Try decrypting key with passphrase.
3868 s
->keyfile
= conf_get_filename(ssh
->conf
, CONF_keyfile
);
3869 ret
= loadrsakey(s
->keyfile
, &s
->key
, passphrase
,
3872 smemclr(passphrase
, strlen(passphrase
));
3876 /* Correct passphrase. */
3877 got_passphrase
= TRUE
;
3878 } else if (ret
== 0) {
3879 c_write_str(ssh
, "Couldn't load private key from ");
3880 c_write_str(ssh
, filename_to_str(s
->keyfile
));
3881 c_write_str(ssh
, " (");
3882 c_write_str(ssh
, error
);
3883 c_write_str(ssh
, ").\r\n");
3884 got_passphrase
= FALSE
;
3885 break; /* go and try something else */
3886 } else if (ret
== -1) {
3887 c_write_str(ssh
, "Wrong passphrase.\r\n"); /* FIXME */
3888 got_passphrase
= FALSE
;
3891 assert(0 && "unexpected return from loadrsakey()");
3892 got_passphrase
= FALSE
; /* placate optimisers */
3896 if (got_passphrase
) {
3899 * Send a public key attempt.
3901 send_packet(ssh
, SSH1_CMSG_AUTH_RSA
,
3902 PKT_BIGNUM
, s
->key
.modulus
, PKT_END
);
3905 if (pktin
->type
== SSH1_SMSG_FAILURE
) {
3906 c_write_str(ssh
, "Server refused our public key.\r\n");
3907 continue; /* go and try something else */
3909 if (pktin
->type
!= SSH1_SMSG_AUTH_RSA_CHALLENGE
) {
3910 bombout(("Bizarre response to offer of public key"));
3916 unsigned char buffer
[32];
3917 Bignum challenge
, response
;
3919 if ((challenge
= ssh1_pkt_getmp(pktin
)) == NULL
) {
3920 bombout(("Server's RSA challenge was badly formatted"));
3923 response
= rsadecrypt(challenge
, &s
->key
);
3924 freebn(s
->key
.private_exponent
);/* burn the evidence */
3926 for (i
= 0; i
< 32; i
++) {
3927 buffer
[i
] = bignum_byte(response
, 31 - i
);
3931 MD5Update(&md5c
, buffer
, 32);
3932 MD5Update(&md5c
, s
->session_id
, 16);
3933 MD5Final(buffer
, &md5c
);
3935 send_packet(ssh
, SSH1_CMSG_AUTH_RSA_RESPONSE
,
3936 PKT_DATA
, buffer
, 16, PKT_END
);
3943 if (pktin
->type
== SSH1_SMSG_FAILURE
) {
3944 if (flags
& FLAG_VERBOSE
)
3945 c_write_str(ssh
, "Failed to authenticate with"
3946 " our public key.\r\n");
3947 continue; /* go and try something else */
3948 } else if (pktin
->type
!= SSH1_SMSG_SUCCESS
) {
3949 bombout(("Bizarre response to RSA authentication response"));
3953 break; /* we're through! */
3959 * Otherwise, try various forms of password-like authentication.
3961 s
->cur_prompt
= new_prompts(ssh
->frontend
);
3963 if (conf_get_int(ssh
->conf
, CONF_try_tis_auth
) &&
3964 (s
->supported_auths_mask
& (1 << SSH1_AUTH_TIS
)) &&
3965 !s
->tis_auth_refused
) {
3966 s
->pwpkt_type
= SSH1_CMSG_AUTH_TIS_RESPONSE
;
3967 logevent("Requested TIS authentication");
3968 send_packet(ssh
, SSH1_CMSG_AUTH_TIS
, PKT_END
);
3970 if (pktin
->type
!= SSH1_SMSG_AUTH_TIS_CHALLENGE
) {
3971 logevent("TIS authentication declined");
3972 if (flags
& FLAG_INTERACTIVE
)
3973 c_write_str(ssh
, "TIS authentication refused.\r\n");
3974 s
->tis_auth_refused
= 1;
3979 char *instr_suf
, *prompt
;
3981 ssh_pkt_getstring(pktin
, &challenge
, &challengelen
);
3983 bombout(("TIS challenge packet was badly formed"));
3986 logevent("Received TIS challenge");
3987 s
->cur_prompt
->to_server
= TRUE
;
3988 s
->cur_prompt
->name
= dupstr("SSH TIS authentication");
3989 /* Prompt heuristic comes from OpenSSH */
3990 if (memchr(challenge
, '\n', challengelen
)) {
3991 instr_suf
= dupstr("");
3992 prompt
= dupprintf("%.*s", challengelen
, challenge
);
3994 instr_suf
= dupprintf("%.*s", challengelen
, challenge
);
3995 prompt
= dupstr("Response: ");
3997 s
->cur_prompt
->instruction
=
3998 dupprintf("Using TIS authentication.%s%s",
3999 (*instr_suf
) ?
"\n" : "",
4001 s
->cur_prompt
->instr_reqd
= TRUE
;
4002 add_prompt(s
->cur_prompt
, prompt
, FALSE
);
4006 if (conf_get_int(ssh
->conf
, CONF_try_tis_auth
) &&
4007 (s
->supported_auths_mask
& (1 << SSH1_AUTH_CCARD
)) &&
4008 !s
->ccard_auth_refused
) {
4009 s
->pwpkt_type
= SSH1_CMSG_AUTH_CCARD_RESPONSE
;
4010 logevent("Requested CryptoCard authentication");
4011 send_packet(ssh
, SSH1_CMSG_AUTH_CCARD
, PKT_END
);
4013 if (pktin
->type
!= SSH1_SMSG_AUTH_CCARD_CHALLENGE
) {
4014 logevent("CryptoCard authentication declined");
4015 c_write_str(ssh
, "CryptoCard authentication refused.\r\n");
4016 s
->ccard_auth_refused
= 1;
4021 char *instr_suf
, *prompt
;
4023 ssh_pkt_getstring(pktin
, &challenge
, &challengelen
);
4025 bombout(("CryptoCard challenge packet was badly formed"));
4028 logevent("Received CryptoCard challenge");
4029 s
->cur_prompt
->to_server
= TRUE
;
4030 s
->cur_prompt
->name
= dupstr("SSH CryptoCard authentication");
4031 s
->cur_prompt
->name_reqd
= FALSE
;
4032 /* Prompt heuristic comes from OpenSSH */
4033 if (memchr(challenge
, '\n', challengelen
)) {
4034 instr_suf
= dupstr("");
4035 prompt
= dupprintf("%.*s", challengelen
, challenge
);
4037 instr_suf
= dupprintf("%.*s", challengelen
, challenge
);
4038 prompt
= dupstr("Response: ");
4040 s
->cur_prompt
->instruction
=
4041 dupprintf("Using CryptoCard authentication.%s%s",
4042 (*instr_suf
) ?
"\n" : "",
4044 s
->cur_prompt
->instr_reqd
= TRUE
;
4045 add_prompt(s
->cur_prompt
, prompt
, FALSE
);
4049 if (s
->pwpkt_type
== SSH1_CMSG_AUTH_PASSWORD
) {
4050 if ((s
->supported_auths_mask
& (1 << SSH1_AUTH_PASSWORD
)) == 0) {
4051 bombout(("No supported authentication methods available"));
4054 s
->cur_prompt
->to_server
= TRUE
;
4055 s
->cur_prompt
->name
= dupstr("SSH password");
4056 add_prompt(s
->cur_prompt
, dupprintf("%s@%s's password: ",
4057 ssh
->username
, ssh
->savedhost
),
4062 * Show password prompt, having first obtained it via a TIS
4063 * or CryptoCard exchange if we're doing TIS or CryptoCard
4067 int ret
; /* need not be kept over crReturn */
4068 ret
= get_userpass_input(s
->cur_prompt
, NULL
, 0);
4071 crWaitUntil(!pktin
);
4072 ret
= get_userpass_input(s
->cur_prompt
, in
, inlen
);
4077 * Failed to get a password (for example
4078 * because one was supplied on the command line
4079 * which has already failed to work). Terminate.
4081 free_prompts(s
->cur_prompt
);
4082 ssh_disconnect(ssh
, NULL
, "Unable to authenticate", 0, TRUE
);
4087 if (s
->pwpkt_type
== SSH1_CMSG_AUTH_PASSWORD
) {
4089 * Defence against traffic analysis: we send a
4090 * whole bunch of packets containing strings of
4091 * different lengths. One of these strings is the
4092 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
4093 * The others are all random data in
4094 * SSH1_MSG_IGNORE packets. This way a passive
4095 * listener can't tell which is the password, and
4096 * hence can't deduce the password length.
4098 * Anybody with a password length greater than 16
4099 * bytes is going to have enough entropy in their
4100 * password that a listener won't find it _that_
4101 * much help to know how long it is. So what we'll
4104 * - if password length < 16, we send 15 packets
4105 * containing string lengths 1 through 15
4107 * - otherwise, we let N be the nearest multiple
4108 * of 8 below the password length, and send 8
4109 * packets containing string lengths N through
4110 * N+7. This won't obscure the order of
4111 * magnitude of the password length, but it will
4112 * introduce a bit of extra uncertainty.
4114 * A few servers can't deal with SSH1_MSG_IGNORE, at
4115 * least in this context. For these servers, we need
4116 * an alternative defence. We make use of the fact
4117 * that the password is interpreted as a C string:
4118 * so we can append a NUL, then some random data.
4120 * A few servers can deal with neither SSH1_MSG_IGNORE
4121 * here _nor_ a padded password string.
4122 * For these servers we are left with no defences
4123 * against password length sniffing.
4125 if (!(ssh
->remote_bugs
& BUG_CHOKES_ON_SSH1_IGNORE
) &&
4126 !(ssh
->remote_bugs
& BUG_NEEDS_SSH1_PLAIN_PASSWORD
)) {
4128 * The server can deal with SSH1_MSG_IGNORE, so
4129 * we can use the primary defence.
4131 int bottom
, top
, pwlen
, i
;
4134 pwlen
= strlen(s
->cur_prompt
->prompts
[0]->result
);
4136 bottom
= 0; /* zero length passwords are OK! :-) */
4139 bottom
= pwlen
& ~7;
4143 assert(pwlen
>= bottom
&& pwlen
<= top
);
4145 randomstr
= snewn(top
+ 1, char);
4147 for (i
= bottom
; i
<= top
; i
++) {
4149 defer_packet(ssh
, s
->pwpkt_type
,
4150 PKTT_PASSWORD
, PKT_STR
,
4151 s
->cur_prompt
->prompts
[0]->result
,
4152 PKTT_OTHER
, PKT_END
);
4154 for (j
= 0; j
< i
; j
++) {
4156 randomstr
[j
] = random_byte();
4157 } while (randomstr
[j
] == '\0');
4159 randomstr
[i
] = '\0';
4160 defer_packet(ssh
, SSH1_MSG_IGNORE
,
4161 PKT_STR
, randomstr
, PKT_END
);
4164 logevent("Sending password with camouflage packets");
4165 ssh_pkt_defersend(ssh
);
4168 else if (!(ssh
->remote_bugs
& BUG_NEEDS_SSH1_PLAIN_PASSWORD
)) {
4170 * The server can't deal with SSH1_MSG_IGNORE
4171 * but can deal with padded passwords, so we
4172 * can use the secondary defence.
4178 len
= strlen(s
->cur_prompt
->prompts
[0]->result
);
4179 if (len
< sizeof(string
)) {
4181 strcpy(string
, s
->cur_prompt
->prompts
[0]->result
);
4182 len
++; /* cover the zero byte */
4183 while (len
< sizeof(string
)) {
4184 string
[len
++] = (char) random_byte();
4187 ss
= s
->cur_prompt
->prompts
[0]->result
;
4189 logevent("Sending length-padded password");
4190 send_packet(ssh
, s
->pwpkt_type
, PKTT_PASSWORD
,
4191 PKT_INT
, len
, PKT_DATA
, ss
, len
,
4192 PKTT_OTHER
, PKT_END
);
4195 * The server is believed unable to cope with
4196 * any of our password camouflage methods.
4199 len
= strlen(s
->cur_prompt
->prompts
[0]->result
);
4200 logevent("Sending unpadded password");
4201 send_packet(ssh
, s
->pwpkt_type
,
4202 PKTT_PASSWORD
, PKT_INT
, len
,
4203 PKT_DATA
, s
->cur_prompt
->prompts
[0]->result
, len
,
4204 PKTT_OTHER
, PKT_END
);
4207 send_packet(ssh
, s
->pwpkt_type
, PKTT_PASSWORD
,
4208 PKT_STR
, s
->cur_prompt
->prompts
[0]->result
,
4209 PKTT_OTHER
, PKT_END
);
4211 logevent("Sent password");
4212 free_prompts(s
->cur_prompt
);
4214 if (pktin
->type
== SSH1_SMSG_FAILURE
) {
4215 if (flags
& FLAG_VERBOSE
)
4216 c_write_str(ssh
, "Access denied\r\n");
4217 logevent("Authentication refused");
4218 } else if (pktin
->type
!= SSH1_SMSG_SUCCESS
) {
4219 bombout(("Strange packet received, type %d", pktin
->type
));
4225 if (s
->publickey_blob
) {
4226 sfree(s
->publickey_blob
);
4227 sfree(s
->publickey_comment
);
4230 logevent("Authentication successful");
4235 static void ssh_channel_try_eof(struct ssh_channel
*c
)
4238 assert(c
->pending_eof
); /* precondition for calling us */
4240 return; /* can't close: not even opened yet */
4241 if (ssh
->version
== 2 && bufchain_size(&c
->v
.v2
.outbuffer
) > 0)
4242 return; /* can't send EOF: pending outgoing data */
4244 c
->pending_eof
= FALSE
; /* we're about to send it */
4245 if (ssh
->version
== 1) {
4246 send_packet(ssh
, SSH1_MSG_CHANNEL_CLOSE
, PKT_INT
, c
->remoteid
,
4248 c
->closes
|= CLOSES_SENT_EOF
;
4250 struct Packet
*pktout
;
4251 pktout
= ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF
);
4252 ssh2_pkt_adduint32(pktout
, c
->remoteid
);
4253 ssh2_pkt_send(ssh
, pktout
);
4254 c
->closes
|= CLOSES_SENT_EOF
;
4255 ssh2_channel_check_close(c
);
4259 void sshfwd_write_eof(struct ssh_channel
*c
)
4263 if (ssh
->state
== SSH_STATE_CLOSED
)
4266 if (c
->closes
& CLOSES_SENT_EOF
)
4269 c
->pending_eof
= TRUE
;
4270 ssh_channel_try_eof(c
);
4273 void sshfwd_unclean_close(struct ssh_channel
*c
)
4277 if (ssh
->state
== SSH_STATE_CLOSED
)
4282 x11_close(c
->u
.x11
.s
);
4283 logevent("Forwarded X11 connection terminated due to local error");
4286 case CHAN_SOCKDATA_DORMANT
:
4287 pfd_close(c
->u
.pfd
.s
);
4288 logevent("Forwarded port closed due to local error");
4291 c
->type
= CHAN_ZOMBIE
;
4293 ssh2_channel_check_close(c
);
4296 int sshfwd_write(struct ssh_channel
*c
, char *buf
, int len
)
4300 if (ssh
->state
== SSH_STATE_CLOSED
)
4303 if (ssh
->version
== 1) {
4304 send_packet(ssh
, SSH1_MSG_CHANNEL_DATA
,
4305 PKT_INT
, c
->remoteid
,
4306 PKT_INT
, len
, PKTT_DATA
, PKT_DATA
, buf
, len
,
4307 PKTT_OTHER
, PKT_END
);
4309 * In SSH-1 we can return 0 here - implying that forwarded
4310 * connections are never individually throttled - because
4311 * the only circumstance that can cause throttling will be
4312 * the whole SSH connection backing up, in which case
4313 * _everything_ will be throttled as a whole.
4317 ssh2_add_channel_data(c
, buf
, len
);
4318 return ssh2_try_send(c
);
4322 void sshfwd_unthrottle(struct ssh_channel
*c
, int bufsize
)
4327 if (ssh
->state
== SSH_STATE_CLOSED
)
4330 if (ssh
->version
== 1) {
4331 buflimit
= SSH1_BUFFER_LIMIT
;
4333 buflimit
= c
->v
.v2
.locmaxwin
;
4334 ssh2_set_window(c
, bufsize
< buflimit ? buflimit
- bufsize
: 0);
4336 if (c
->throttling_conn
&& bufsize
<= buflimit
) {
4337 c
->throttling_conn
= 0;
4338 ssh_throttle_conn(ssh
, -1);
4342 static void ssh_queueing_handler(Ssh ssh
, struct Packet
*pktin
)
4344 struct queued_handler
*qh
= ssh
->qhead
;
4348 assert(pktin
->type
== qh
->msg1
|| pktin
->type
== qh
->msg2
);
4351 assert(ssh
->packet_dispatch
[qh
->msg1
] == ssh_queueing_handler
);
4352 ssh
->packet_dispatch
[qh
->msg1
] = ssh
->q_saved_handler1
;
4355 assert(ssh
->packet_dispatch
[qh
->msg2
] == ssh_queueing_handler
);
4356 ssh
->packet_dispatch
[qh
->msg2
] = ssh
->q_saved_handler2
;
4360 ssh
->qhead
= qh
->next
;
4362 if (ssh
->qhead
->msg1
> 0) {
4363 ssh
->q_saved_handler1
= ssh
->packet_dispatch
[ssh
->qhead
->msg1
];
4364 ssh
->packet_dispatch
[ssh
->qhead
->msg1
] = ssh_queueing_handler
;
4366 if (ssh
->qhead
->msg2
> 0) {
4367 ssh
->q_saved_handler2
= ssh
->packet_dispatch
[ssh
->qhead
->msg2
];
4368 ssh
->packet_dispatch
[ssh
->qhead
->msg2
] = ssh_queueing_handler
;
4371 ssh
->qhead
= ssh
->qtail
= NULL
;
4374 qh
->handler(ssh
, pktin
, qh
->ctx
);
4379 static void ssh_queue_handler(Ssh ssh
, int msg1
, int msg2
,
4380 chandler_fn_t handler
, void *ctx
)
4382 struct queued_handler
*qh
;
4384 qh
= snew(struct queued_handler
);
4387 qh
->handler
= handler
;
4391 if (ssh
->qtail
== NULL
) {
4395 ssh
->q_saved_handler1
= ssh
->packet_dispatch
[ssh
->qhead
->msg1
];
4396 ssh
->packet_dispatch
[qh
->msg1
] = ssh_queueing_handler
;
4399 ssh
->q_saved_handler2
= ssh
->packet_dispatch
[ssh
->qhead
->msg2
];
4400 ssh
->packet_dispatch
[qh
->msg2
] = ssh_queueing_handler
;
4403 ssh
->qtail
->next
= qh
;
4408 static void ssh_rportfwd_succfail(Ssh ssh
, struct Packet
*pktin
, void *ctx
)
4410 struct ssh_rportfwd
*rpf
, *pf
= (struct ssh_rportfwd
*)ctx
;
4412 if (pktin
->type
== (ssh
->version
== 1 ? SSH1_SMSG_SUCCESS
:
4413 SSH2_MSG_REQUEST_SUCCESS
)) {
4414 logeventf(ssh
, "Remote port forwarding from %s enabled",
4417 logeventf(ssh
, "Remote port forwarding from %s refused",
4420 rpf
= del234(ssh
->rportfwds
, pf
);
4422 pf
->pfrec
->remote
= NULL
;
4427 static void ssh_setup_portfwd(Ssh ssh
, Conf
*conf
)
4429 struct ssh_portfwd
*epf
;
4433 if (!ssh
->portfwds
) {
4434 ssh
->portfwds
= newtree234(ssh_portcmp
);
4437 * Go through the existing port forwardings and tag them
4438 * with status==DESTROY. Any that we want to keep will be
4439 * re-enabled (status==KEEP) as we go through the
4440 * configuration and find out which bits are the same as
4443 struct ssh_portfwd
*epf
;
4445 for (i
= 0; (epf
= index234(ssh
->portfwds
, i
)) != NULL
; i
++)
4446 epf
->status
= DESTROY
;
4449 for (val
= conf_get_str_strs(conf
, CONF_portfwd
, NULL
, &key
);
4451 val
= conf_get_str_strs(conf
, CONF_portfwd
, key
, &key
)) {
4452 char *kp
, *kp2
, *vp
, *vp2
;
4453 char address_family
, type
;
4454 int sport
,dport
,sserv
,dserv
;
4455 char *sports
, *dports
, *saddr
, *host
;
4459 address_family
= 'A';
4461 if (*kp
== 'A' || *kp
== '4' || *kp
== '6')
4462 address_family
= *kp
++;
4463 if (*kp
== 'L' || *kp
== 'R')
4466 if ((kp2
= strchr(kp
, ':')) != NULL
) {
4468 * There's a colon in the middle of the source port
4469 * string, which means that the part before it is
4470 * actually a source address.
4472 saddr
= dupprintf("%.*s", (int)(kp2
- kp
), kp
);
4478 sport
= atoi(sports
);
4482 sport
= net_service_lookup(sports
);
4484 logeventf(ssh
, "Service lookup failed for source"
4485 " port \"%s\"", sports
);
4489 if (type
== 'L' && !strcmp(val
, "D")) {
4490 /* dynamic forwarding */
4497 /* ordinary forwarding */
4499 vp2
= vp
+ strcspn(vp
, ":");
4500 host
= dupprintf("%.*s", (int)(vp2
- vp
), vp
);
4504 dport
= atoi(dports
);
4508 dport
= net_service_lookup(dports
);
4510 logeventf(ssh
, "Service lookup failed for destination"
4511 " port \"%s\"", dports
);
4516 if (sport
&& dport
) {
4517 /* Set up a description of the source port. */
4518 struct ssh_portfwd
*pfrec
, *epfrec
;
4520 pfrec
= snew(struct ssh_portfwd
);
4522 pfrec
->saddr
= saddr
;
4523 pfrec
->sserv
= sserv ?
dupstr(sports
) : NULL
;
4524 pfrec
->sport
= sport
;
4525 pfrec
->daddr
= host
;
4526 pfrec
->dserv
= dserv ?
dupstr(dports
) : NULL
;
4527 pfrec
->dport
= dport
;
4528 pfrec
->local
= NULL
;
4529 pfrec
->remote
= NULL
;
4530 pfrec
->addressfamily
= (address_family
== '4' ? ADDRTYPE_IPV4
:
4531 address_family
== '6' ? ADDRTYPE_IPV6
:
4534 epfrec
= add234(ssh
->portfwds
, pfrec
);
4535 if (epfrec
!= pfrec
) {
4536 if (epfrec
->status
== DESTROY
) {
4538 * We already have a port forwarding up and running
4539 * with precisely these parameters. Hence, no need
4540 * to do anything; simply re-tag the existing one
4543 epfrec
->status
= KEEP
;
4546 * Anything else indicates that there was a duplicate
4547 * in our input, which we'll silently ignore.
4549 free_portfwd(pfrec
);
4551 pfrec
->status
= CREATE
;
4560 * Now go through and destroy any port forwardings which were
4563 for (i
= 0; (epf
= index234(ssh
->portfwds
, i
)) != NULL
; i
++)
4564 if (epf
->status
== DESTROY
) {
4567 message
= dupprintf("%s port forwarding from %s%s%d",
4568 epf
->type
== 'L' ?
"local" :
4569 epf
->type
== 'R' ?
"remote" : "dynamic",
4570 epf
->saddr ? epf
->saddr
: "",
4571 epf
->saddr ?
":" : "",
4574 if (epf
->type
!= 'D') {
4575 char *msg2
= dupprintf("%s to %s:%d", message
,
4576 epf
->daddr
, epf
->dport
);
4581 logeventf(ssh
, "Cancelling %s", message
);
4584 /* epf->remote or epf->local may be NULL if setting up a
4585 * forwarding failed. */
4587 struct ssh_rportfwd
*rpf
= epf
->remote
;
4588 struct Packet
*pktout
;
4591 * Cancel the port forwarding at the server
4594 if (ssh
->version
== 1) {
4596 * We cannot cancel listening ports on the
4597 * server side in SSH-1! There's no message
4598 * to support it. Instead, we simply remove
4599 * the rportfwd record from the local end
4600 * so that any connections the server tries
4601 * to make on it are rejected.
4604 pktout
= ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST
);
4605 ssh2_pkt_addstring(pktout
, "cancel-tcpip-forward");
4606 ssh2_pkt_addbool(pktout
, 0);/* _don't_ want reply */
4608 ssh2_pkt_addstring(pktout
, epf
->saddr
);
4609 } else if (conf_get_int(conf
, CONF_rport_acceptall
)) {
4610 /* XXX: rport_acceptall may not represent
4611 * what was used to open the original connection,
4612 * since it's reconfigurable. */
4613 ssh2_pkt_addstring(pktout
, "0.0.0.0");
4615 ssh2_pkt_addstring(pktout
, "127.0.0.1");
4617 ssh2_pkt_adduint32(pktout
, epf
->sport
);
4618 ssh2_pkt_send(ssh
, pktout
);
4621 del234(ssh
->rportfwds
, rpf
);
4623 } else if (epf
->local
) {
4624 pfd_terminate(epf
->local
);
4627 delpos234(ssh
->portfwds
, i
);
4629 i
--; /* so we don't skip one in the list */
4633 * And finally, set up any new port forwardings (status==CREATE).
4635 for (i
= 0; (epf
= index234(ssh
->portfwds
, i
)) != NULL
; i
++)
4636 if (epf
->status
== CREATE
) {
4637 char *sportdesc
, *dportdesc
;
4638 sportdesc
= dupprintf("%s%s%s%s%d%s",
4639 epf
->saddr ? epf
->saddr
: "",
4640 epf
->saddr ?
":" : "",
4641 epf
->sserv ? epf
->sserv
: "",
4642 epf
->sserv ?
"(" : "",
4644 epf
->sserv ?
")" : "");
4645 if (epf
->type
== 'D') {
4648 dportdesc
= dupprintf("%s:%s%s%d%s",
4650 epf
->dserv ? epf
->dserv
: "",
4651 epf
->dserv ?
"(" : "",
4653 epf
->dserv ?
")" : "");
4656 if (epf
->type
== 'L') {
4657 const char *err
= pfd_addforward(epf
->daddr
, epf
->dport
,
4658 epf
->saddr
, epf
->sport
,
4661 epf
->addressfamily
);
4663 logeventf(ssh
, "Local %sport %s forwarding to %s%s%s",
4664 epf
->addressfamily
== ADDRTYPE_IPV4 ?
"IPv4 " :
4665 epf
->addressfamily
== ADDRTYPE_IPV6 ?
"IPv6 " : "",
4666 sportdesc
, dportdesc
,
4667 err ?
" failed: " : "", err ? err
: "");
4668 } else if (epf
->type
== 'D') {
4669 const char *err
= pfd_addforward(NULL
, -1,
4670 epf
->saddr
, epf
->sport
,
4673 epf
->addressfamily
);
4675 logeventf(ssh
, "Local %sport %s SOCKS dynamic forwarding%s%s",
4676 epf
->addressfamily
== ADDRTYPE_IPV4 ?
"IPv4 " :
4677 epf
->addressfamily
== ADDRTYPE_IPV6 ?
"IPv6 " : "",
4679 err ?
" failed: " : "", err ? err
: "");
4681 struct ssh_rportfwd
*pf
;
4684 * Ensure the remote port forwardings tree exists.
4686 if (!ssh
->rportfwds
) {
4687 if (ssh
->version
== 1)
4688 ssh
->rportfwds
= newtree234(ssh_rportcmp_ssh1
);
4690 ssh
->rportfwds
= newtree234(ssh_rportcmp_ssh2
);
4693 pf
= snew(struct ssh_rportfwd
);
4694 strncpy(pf
->dhost
, epf
->daddr
, lenof(pf
->dhost
)-1);
4695 pf
->dhost
[lenof(pf
->dhost
)-1] = '\0';
4696 pf
->dport
= epf
->dport
;
4697 pf
->sport
= epf
->sport
;
4698 if (add234(ssh
->rportfwds
, pf
) != pf
) {
4699 logeventf(ssh
, "Duplicate remote port forwarding to %s:%d",
4700 epf
->daddr
, epf
->dport
);
4703 logeventf(ssh
, "Requesting remote port %s"
4704 " forward to %s", sportdesc
, dportdesc
);
4706 pf
->sportdesc
= sportdesc
;
4711 if (ssh
->version
== 1) {
4712 send_packet(ssh
, SSH1_CMSG_PORT_FORWARD_REQUEST
,
4713 PKT_INT
, epf
->sport
,
4714 PKT_STR
, epf
->daddr
,
4715 PKT_INT
, epf
->dport
,
4717 ssh_queue_handler(ssh
, SSH1_SMSG_SUCCESS
,
4719 ssh_rportfwd_succfail
, pf
);
4721 struct Packet
*pktout
;
4722 pktout
= ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST
);
4723 ssh2_pkt_addstring(pktout
, "tcpip-forward");
4724 ssh2_pkt_addbool(pktout
, 1);/* want reply */
4726 ssh2_pkt_addstring(pktout
, epf
->saddr
);
4727 } else if (conf_get_int(conf
, CONF_rport_acceptall
)) {
4728 ssh2_pkt_addstring(pktout
, "0.0.0.0");
4730 ssh2_pkt_addstring(pktout
, "127.0.0.1");
4732 ssh2_pkt_adduint32(pktout
, epf
->sport
);
4733 ssh2_pkt_send(ssh
, pktout
);
4735 ssh_queue_handler(ssh
, SSH2_MSG_REQUEST_SUCCESS
,
4736 SSH2_MSG_REQUEST_FAILURE
,
4737 ssh_rportfwd_succfail
, pf
);
4746 static void ssh1_smsg_stdout_stderr_data(Ssh ssh
, struct Packet
*pktin
)
4749 int stringlen
, bufsize
;
4751 ssh_pkt_getstring(pktin
, &string
, &stringlen
);
4752 if (string
== NULL
) {
4753 bombout(("Incoming terminal data packet was badly formed"));
4757 bufsize
= from_backend(ssh
->frontend
, pktin
->type
== SSH1_SMSG_STDERR_DATA
,
4759 if (!ssh
->v1_stdout_throttling
&& bufsize
> SSH1_BUFFER_LIMIT
) {
4760 ssh
->v1_stdout_throttling
= 1;
4761 ssh_throttle_conn(ssh
, +1);
4765 static void ssh1_smsg_x11_open(Ssh ssh
, struct Packet
*pktin
)
4767 /* Remote side is trying to open a channel to talk to our
4768 * X-Server. Give them back a local channel number. */
4769 struct ssh_channel
*c
;
4770 int remoteid
= ssh_pkt_getuint32(pktin
);
4772 logevent("Received X11 connect request");
4773 /* Refuse if X11 forwarding is disabled. */
4774 if (!ssh
->X11_fwd_enabled
) {
4775 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_FAILURE
,
4776 PKT_INT
, remoteid
, PKT_END
);
4777 logevent("Rejected X11 connect request");
4779 c
= snew(struct ssh_channel
);
4782 if (x11_init(&c
->u
.x11
.s
, ssh
->x11disp
, c
,
4783 NULL
, -1, ssh
->conf
) != NULL
) {
4784 logevent("Opening X11 forward connection failed");
4786 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_FAILURE
,
4787 PKT_INT
, remoteid
, PKT_END
);
4790 ("Opening X11 forward connection succeeded");
4791 c
->remoteid
= remoteid
;
4792 c
->halfopen
= FALSE
;
4793 c
->localid
= alloc_channel_id(ssh
);
4795 c
->pending_eof
= FALSE
;
4796 c
->throttling_conn
= 0;
4797 c
->type
= CHAN_X11
; /* identify channel type */
4798 add234(ssh
->channels
, c
);
4799 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
,
4800 PKT_INT
, c
->remoteid
, PKT_INT
,
4801 c
->localid
, PKT_END
);
4802 logevent("Opened X11 forward channel");
4807 static void ssh1_smsg_agent_open(Ssh ssh
, struct Packet
*pktin
)
4809 /* Remote side is trying to open a channel to talk to our
4810 * agent. Give them back a local channel number. */
4811 struct ssh_channel
*c
;
4812 int remoteid
= ssh_pkt_getuint32(pktin
);
4814 /* Refuse if agent forwarding is disabled. */
4815 if (!ssh
->agentfwd_enabled
) {
4816 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_FAILURE
,
4817 PKT_INT
, remoteid
, PKT_END
);
4819 c
= snew(struct ssh_channel
);
4821 c
->remoteid
= remoteid
;
4822 c
->halfopen
= FALSE
;
4823 c
->localid
= alloc_channel_id(ssh
);
4825 c
->pending_eof
= FALSE
;
4826 c
->throttling_conn
= 0;
4827 c
->type
= CHAN_AGENT
; /* identify channel type */
4828 c
->u
.a
.lensofar
= 0;
4829 c
->u
.a
.message
= NULL
;
4830 add234(ssh
->channels
, c
);
4831 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
,
4832 PKT_INT
, c
->remoteid
, PKT_INT
, c
->localid
,
4837 static void ssh1_msg_port_open(Ssh ssh
, struct Packet
*pktin
)
4839 /* Remote side is trying to open a channel to talk to a
4840 * forwarded port. Give them back a local channel number. */
4841 struct ssh_channel
*c
;
4842 struct ssh_rportfwd pf
, *pfp
;
4847 c
= snew(struct ssh_channel
);
4850 remoteid
= ssh_pkt_getuint32(pktin
);
4851 ssh_pkt_getstring(pktin
, &host
, &hostsize
);
4852 port
= ssh_pkt_getuint32(pktin
);
4854 if (hostsize
>= lenof(pf
.dhost
))
4855 hostsize
= lenof(pf
.dhost
)-1;
4856 memcpy(pf
.dhost
, host
, hostsize
);
4857 pf
.dhost
[hostsize
] = '\0';
4859 pfp
= find234(ssh
->rportfwds
, &pf
, NULL
);
4862 logeventf(ssh
, "Rejected remote port open request for %s:%d",
4864 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_FAILURE
,
4865 PKT_INT
, remoteid
, PKT_END
);
4867 logeventf(ssh
, "Received remote port open request for %s:%d",
4869 e
= pfd_newconnect(&c
->u
.pfd
.s
, pf
.dhost
, port
,
4870 c
, ssh
->conf
, pfp
->pfrec
->addressfamily
);
4872 logeventf(ssh
, "Port open failed: %s", e
);
4874 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_FAILURE
,
4875 PKT_INT
, remoteid
, PKT_END
);
4877 c
->remoteid
= remoteid
;
4878 c
->halfopen
= FALSE
;
4879 c
->localid
= alloc_channel_id(ssh
);
4881 c
->pending_eof
= FALSE
;
4882 c
->throttling_conn
= 0;
4883 c
->type
= CHAN_SOCKDATA
; /* identify channel type */
4884 add234(ssh
->channels
, c
);
4885 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
,
4886 PKT_INT
, c
->remoteid
, PKT_INT
,
4887 c
->localid
, PKT_END
);
4888 logevent("Forwarded port opened successfully");
4893 static void ssh1_msg_channel_open_confirmation(Ssh ssh
, struct Packet
*pktin
)
4895 unsigned int remoteid
= ssh_pkt_getuint32(pktin
);
4896 unsigned int localid
= ssh_pkt_getuint32(pktin
);
4897 struct ssh_channel
*c
;
4899 c
= find234(ssh
->channels
, &remoteid
, ssh_channelfind
);
4900 if (c
&& c
->type
== CHAN_SOCKDATA_DORMANT
) {
4901 c
->remoteid
= localid
;
4902 c
->halfopen
= FALSE
;
4903 c
->type
= CHAN_SOCKDATA
;
4904 c
->throttling_conn
= 0;
4905 pfd_confirm(c
->u
.pfd
.s
);
4908 if (c
&& c
->pending_eof
) {
4910 * We have a pending close on this channel,
4911 * which we decided on before the server acked
4912 * the channel open. So now we know the
4913 * remoteid, we can close it again.
4915 ssh_channel_try_eof(c
);
4919 static void ssh1_msg_channel_open_failure(Ssh ssh
, struct Packet
*pktin
)
4921 unsigned int remoteid
= ssh_pkt_getuint32(pktin
);
4922 struct ssh_channel
*c
;
4924 c
= find234(ssh
->channels
, &remoteid
, ssh_channelfind
);
4925 if (c
&& c
->type
== CHAN_SOCKDATA_DORMANT
) {
4926 logevent("Forwarded connection refused by server");
4927 pfd_close(c
->u
.pfd
.s
);
4928 del234(ssh
->channels
, c
);
4933 static void ssh1_msg_channel_close(Ssh ssh
, struct Packet
*pktin
)
4935 /* Remote side closes a channel. */
4936 unsigned i
= ssh_pkt_getuint32(pktin
);
4937 struct ssh_channel
*c
;
4938 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
4939 if (c
&& !c
->halfopen
) {
4941 if (pktin
->type
== SSH1_MSG_CHANNEL_CLOSE
&&
4942 !(c
->closes
& CLOSES_RCVD_EOF
)) {
4944 * Received CHANNEL_CLOSE, which we translate into
4947 int send_close
= FALSE
;
4949 c
->closes
|= CLOSES_RCVD_EOF
;
4954 x11_send_eof(c
->u
.x11
.s
);
4960 pfd_send_eof(c
->u
.pfd
.s
);
4969 if (send_close
&& !(c
->closes
& CLOSES_SENT_EOF
)) {
4970 send_packet(ssh
, SSH1_MSG_CHANNEL_CLOSE
, PKT_INT
, c
->remoteid
,
4972 c
->closes
|= CLOSES_SENT_EOF
;
4976 if (pktin
->type
== SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION
&&
4977 !(c
->closes
& CLOSES_RCVD_CLOSE
)) {
4979 if (!(c
->closes
& CLOSES_SENT_EOF
)) {
4980 bombout(("Received CHANNEL_CLOSE_CONFIRMATION for channel %d"
4981 " for which we never sent CHANNEL_CLOSE\n", i
));
4984 c
->closes
|= CLOSES_RCVD_CLOSE
;
4987 if (!((CLOSES_SENT_EOF
| CLOSES_RCVD_EOF
) & ~c
->closes
) &&
4988 !(c
->closes
& CLOSES_SENT_CLOSE
)) {
4989 send_packet(ssh
, SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION
,
4990 PKT_INT
, c
->remoteid
, PKT_END
);
4991 c
->closes
|= CLOSES_SENT_CLOSE
;
4994 if (!((CLOSES_SENT_CLOSE
| CLOSES_RCVD_CLOSE
) & ~c
->closes
))
4995 ssh_channel_destroy(c
);
4997 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
4998 pktin
->type
== SSH1_MSG_CHANNEL_CLOSE ?
"" :
4999 "_CONFIRMATION", c ?
"half-open" : "nonexistent",
5004 static void ssh1_msg_channel_data(Ssh ssh
, struct Packet
*pktin
)
5006 /* Data sent down one of our channels. */
5007 int i
= ssh_pkt_getuint32(pktin
);
5010 struct ssh_channel
*c
;
5012 ssh_pkt_getstring(pktin
, &p
, &len
);
5014 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5019 bufsize
= x11_send(c
->u
.x11
.s
, p
, len
);
5022 bufsize
= pfd_send(c
->u
.pfd
.s
, p
, len
);
5025 /* Data for an agent message. Buffer it. */
5027 if (c
->u
.a
.lensofar
< 4) {
5028 unsigned int l
= min(4 - c
->u
.a
.lensofar
, (unsigned)len
);
5029 memcpy(c
->u
.a
.msglen
+ c
->u
.a
.lensofar
, p
,
5033 c
->u
.a
.lensofar
+= l
;
5035 if (c
->u
.a
.lensofar
== 4) {
5037 4 + GET_32BIT(c
->u
.a
.msglen
);
5038 c
->u
.a
.message
= snewn(c
->u
.a
.totallen
,
5040 memcpy(c
->u
.a
.message
, c
->u
.a
.msglen
, 4);
5042 if (c
->u
.a
.lensofar
>= 4 && len
> 0) {
5044 min(c
->u
.a
.totallen
- c
->u
.a
.lensofar
,
5046 memcpy(c
->u
.a
.message
+ c
->u
.a
.lensofar
, p
,
5050 c
->u
.a
.lensofar
+= l
;
5052 if (c
->u
.a
.lensofar
== c
->u
.a
.totallen
) {
5055 if (agent_query(c
->u
.a
.message
,
5058 ssh_agentf_callback
, c
))
5059 ssh_agentf_callback(c
, reply
, replylen
);
5060 sfree(c
->u
.a
.message
);
5061 c
->u
.a
.lensofar
= 0;
5064 bufsize
= 0; /* agent channels never back up */
5067 if (!c
->throttling_conn
&& bufsize
> SSH1_BUFFER_LIMIT
) {
5068 c
->throttling_conn
= 1;
5069 ssh_throttle_conn(ssh
, +1);
5074 static void ssh1_smsg_exit_status(Ssh ssh
, struct Packet
*pktin
)
5076 ssh
->exitcode
= ssh_pkt_getuint32(pktin
);
5077 logeventf(ssh
, "Server sent command exit status %d", ssh
->exitcode
);
5078 send_packet(ssh
, SSH1_CMSG_EXIT_CONFIRMATION
, PKT_END
);
5080 * In case `helpful' firewalls or proxies tack
5081 * extra human-readable text on the end of the
5082 * session which we might mistake for another
5083 * encrypted packet, we close the session once
5084 * we've sent EXIT_CONFIRMATION.
5086 ssh_disconnect(ssh
, NULL
, NULL
, 0, TRUE
);
5089 /* Helper function to deal with sending tty modes for REQUEST_PTY */
5090 static void ssh1_send_ttymode(void *data
, char *mode
, char *val
)
5092 struct Packet
*pktout
= (struct Packet
*)data
;
5094 unsigned int arg
= 0;
5095 while (strcmp(mode
, ssh_ttymodes
[i
].mode
) != 0) i
++;
5096 if (i
== lenof(ssh_ttymodes
)) return;
5097 switch (ssh_ttymodes
[i
].type
) {
5099 arg
= ssh_tty_parse_specchar(val
);
5102 arg
= ssh_tty_parse_boolean(val
);
5105 ssh2_pkt_addbyte(pktout
, ssh_ttymodes
[i
].opcode
);
5106 ssh2_pkt_addbyte(pktout
, arg
);
5110 static void do_ssh1_connection(Ssh ssh
, unsigned char *in
, int inlen
,
5111 struct Packet
*pktin
)
5113 crBegin(ssh
->do_ssh1_connection_crstate
);
5115 ssh
->packet_dispatch
[SSH1_SMSG_STDOUT_DATA
] =
5116 ssh
->packet_dispatch
[SSH1_SMSG_STDERR_DATA
] =
5117 ssh1_smsg_stdout_stderr_data
;
5119 ssh
->packet_dispatch
[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
] =
5120 ssh1_msg_channel_open_confirmation
;
5121 ssh
->packet_dispatch
[SSH1_MSG_CHANNEL_OPEN_FAILURE
] =
5122 ssh1_msg_channel_open_failure
;
5123 ssh
->packet_dispatch
[SSH1_MSG_CHANNEL_CLOSE
] =
5124 ssh
->packet_dispatch
[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION
] =
5125 ssh1_msg_channel_close
;
5126 ssh
->packet_dispatch
[SSH1_MSG_CHANNEL_DATA
] = ssh1_msg_channel_data
;
5127 ssh
->packet_dispatch
[SSH1_SMSG_EXIT_STATUS
] = ssh1_smsg_exit_status
;
5129 if (conf_get_int(ssh
->conf
, CONF_agentfwd
) && agent_exists()) {
5130 logevent("Requesting agent forwarding");
5131 send_packet(ssh
, SSH1_CMSG_AGENT_REQUEST_FORWARDING
, PKT_END
);
5135 if (pktin
->type
!= SSH1_SMSG_SUCCESS
5136 && pktin
->type
!= SSH1_SMSG_FAILURE
) {
5137 bombout(("Protocol confusion"));
5139 } else if (pktin
->type
== SSH1_SMSG_FAILURE
) {
5140 logevent("Agent forwarding refused");
5142 logevent("Agent forwarding enabled");
5143 ssh
->agentfwd_enabled
= TRUE
;
5144 ssh
->packet_dispatch
[SSH1_SMSG_AGENT_OPEN
] = ssh1_smsg_agent_open
;
5148 if (conf_get_int(ssh
->conf
, CONF_x11_forward
) &&
5149 (ssh
->x11disp
= x11_setup_display(conf_get_str(ssh
->conf
, CONF_x11_display
),
5150 conf_get_int(ssh
->conf
, CONF_x11_auth
), ssh
->conf
))) {
5151 logevent("Requesting X11 forwarding");
5153 * Note that while we blank the X authentication data here, we don't
5154 * take any special action to blank the start of an X11 channel,
5155 * so using MIT-MAGIC-COOKIE-1 and actually opening an X connection
5156 * without having session blanking enabled is likely to leak your
5157 * cookie into the log.
5159 if (ssh
->v1_local_protoflags
& SSH1_PROTOFLAG_SCREEN_NUMBER
) {
5160 send_packet(ssh
, SSH1_CMSG_X11_REQUEST_FORWARDING
,
5161 PKT_STR
, ssh
->x11disp
->remoteauthprotoname
,
5163 PKT_STR
, ssh
->x11disp
->remoteauthdatastring
,
5165 PKT_INT
, ssh
->x11disp
->screennum
,
5168 send_packet(ssh
, SSH1_CMSG_X11_REQUEST_FORWARDING
,
5169 PKT_STR
, ssh
->x11disp
->remoteauthprotoname
,
5171 PKT_STR
, ssh
->x11disp
->remoteauthdatastring
,
5178 if (pktin
->type
!= SSH1_SMSG_SUCCESS
5179 && pktin
->type
!= SSH1_SMSG_FAILURE
) {
5180 bombout(("Protocol confusion"));
5182 } else if (pktin
->type
== SSH1_SMSG_FAILURE
) {
5183 logevent("X11 forwarding refused");
5185 logevent("X11 forwarding enabled");
5186 ssh
->X11_fwd_enabled
= TRUE
;
5187 ssh
->packet_dispatch
[SSH1_SMSG_X11_OPEN
] = ssh1_smsg_x11_open
;
5191 ssh_setup_portfwd(ssh
, ssh
->conf
);
5192 ssh
->packet_dispatch
[SSH1_MSG_PORT_OPEN
] = ssh1_msg_port_open
;
5194 if (!conf_get_int(ssh
->conf
, CONF_nopty
)) {
5196 /* Unpick the terminal-speed string. */
5197 /* XXX perhaps we should allow no speeds to be sent. */
5198 ssh
->ospeed
= 38400; ssh
->ispeed
= 38400; /* last-resort defaults */
5199 sscanf(conf_get_str(ssh
->conf
, CONF_termspeed
), "%d,%d", &ssh
->ospeed
, &ssh
->ispeed
);
5200 /* Send the pty request. */
5201 pkt
= ssh1_pkt_init(SSH1_CMSG_REQUEST_PTY
);
5202 ssh_pkt_addstring(pkt
, conf_get_str(ssh
->conf
, CONF_termtype
));
5203 ssh_pkt_adduint32(pkt
, ssh
->term_height
);
5204 ssh_pkt_adduint32(pkt
, ssh
->term_width
);
5205 ssh_pkt_adduint32(pkt
, 0); /* width in pixels */
5206 ssh_pkt_adduint32(pkt
, 0); /* height in pixels */
5207 parse_ttymodes(ssh
, ssh1_send_ttymode
, (void *)pkt
);
5208 ssh_pkt_addbyte(pkt
, SSH1_TTY_OP_ISPEED
);
5209 ssh_pkt_adduint32(pkt
, ssh
->ispeed
);
5210 ssh_pkt_addbyte(pkt
, SSH1_TTY_OP_OSPEED
);
5211 ssh_pkt_adduint32(pkt
, ssh
->ospeed
);
5212 ssh_pkt_addbyte(pkt
, SSH_TTY_OP_END
);
5214 ssh
->state
= SSH_STATE_INTERMED
;
5218 if (pktin
->type
!= SSH1_SMSG_SUCCESS
5219 && pktin
->type
!= SSH1_SMSG_FAILURE
) {
5220 bombout(("Protocol confusion"));
5222 } else if (pktin
->type
== SSH1_SMSG_FAILURE
) {
5223 c_write_str(ssh
, "Server refused to allocate pty\r\n");
5224 ssh
->editing
= ssh
->echoing
= 1;
5226 logeventf(ssh
, "Allocated pty (ospeed %dbps, ispeed %dbps)",
5227 ssh
->ospeed
, ssh
->ispeed
);
5228 ssh
->got_pty
= TRUE
;
5231 ssh
->editing
= ssh
->echoing
= 1;
5234 if (conf_get_int(ssh
->conf
, CONF_compression
)) {
5235 send_packet(ssh
, SSH1_CMSG_REQUEST_COMPRESSION
, PKT_INT
, 6, PKT_END
);
5239 if (pktin
->type
!= SSH1_SMSG_SUCCESS
5240 && pktin
->type
!= SSH1_SMSG_FAILURE
) {
5241 bombout(("Protocol confusion"));
5243 } else if (pktin
->type
== SSH1_SMSG_FAILURE
) {
5244 c_write_str(ssh
, "Server refused to compress\r\n");
5246 logevent("Started compression");
5247 ssh
->v1_compressing
= TRUE
;
5248 ssh
->cs_comp_ctx
= zlib_compress_init();
5249 logevent("Initialised zlib (RFC1950) compression");
5250 ssh
->sc_comp_ctx
= zlib_decompress_init();
5251 logevent("Initialised zlib (RFC1950) decompression");
5255 * Start the shell or command.
5257 * Special case: if the first-choice command is an SSH-2
5258 * subsystem (hence not usable here) and the second choice
5259 * exists, we fall straight back to that.
5262 char *cmd
= conf_get_str(ssh
->conf
, CONF_remote_cmd
);
5264 if (conf_get_int(ssh
->conf
, CONF_ssh_subsys
) &&
5265 conf_get_str(ssh
->conf
, CONF_remote_cmd2
)) {
5266 cmd
= conf_get_str(ssh
->conf
, CONF_remote_cmd2
);
5267 ssh
->fallback_cmd
= TRUE
;
5270 send_packet(ssh
, SSH1_CMSG_EXEC_CMD
, PKT_STR
, cmd
, PKT_END
);
5272 send_packet(ssh
, SSH1_CMSG_EXEC_SHELL
, PKT_END
);
5273 logevent("Started session");
5276 ssh
->state
= SSH_STATE_SESSION
;
5277 if (ssh
->size_needed
)
5278 ssh_size(ssh
, ssh
->term_width
, ssh
->term_height
);
5279 if (ssh
->eof_needed
)
5280 ssh_special(ssh
, TS_EOF
);
5283 ldisc_send(ssh
->ldisc
, NULL
, 0, 0);/* cause ldisc to notice changes */
5285 ssh
->channels
= newtree234(ssh_channelcmp
);
5289 * By this point, most incoming packets are already being
5290 * handled by the dispatch table, and we need only pay
5291 * attention to the unusual ones.
5296 if (pktin
->type
== SSH1_SMSG_SUCCESS
) {
5297 /* may be from EXEC_SHELL on some servers */
5298 } else if (pktin
->type
== SSH1_SMSG_FAILURE
) {
5299 /* may be from EXEC_SHELL on some servers
5300 * if no pty is available or in other odd cases. Ignore */
5302 bombout(("Strange packet received: type %d", pktin
->type
));
5307 int len
= min(inlen
, 512);
5308 send_packet(ssh
, SSH1_CMSG_STDIN_DATA
,
5309 PKT_INT
, len
, PKTT_DATA
, PKT_DATA
, in
, len
,
5310 PKTT_OTHER
, PKT_END
);
5321 * Handle the top-level SSH-2 protocol.
5323 static void ssh1_msg_debug(Ssh ssh
, struct Packet
*pktin
)
5328 ssh_pkt_getstring(pktin
, &msg
, &msglen
);
5329 logeventf(ssh
, "Remote debug message: %.*s", msglen
, msg
);
5332 static void ssh1_msg_disconnect(Ssh ssh
, struct Packet
*pktin
)
5334 /* log reason code in disconnect message */
5338 ssh_pkt_getstring(pktin
, &msg
, &msglen
);
5339 bombout(("Server sent disconnect message:\n\"%.*s\"", msglen
, msg
));
5342 static void ssh_msg_ignore(Ssh ssh
, struct Packet
*pktin
)
5344 /* Do nothing, because we're ignoring it! Duhh. */
5347 static void ssh1_protocol_setup(Ssh ssh
)
5352 * Most messages are handled by the coroutines.
5354 for (i
= 0; i
< 256; i
++)
5355 ssh
->packet_dispatch
[i
] = NULL
;
5358 * These special message types we install handlers for.
5360 ssh
->packet_dispatch
[SSH1_MSG_DISCONNECT
] = ssh1_msg_disconnect
;
5361 ssh
->packet_dispatch
[SSH1_MSG_IGNORE
] = ssh_msg_ignore
;
5362 ssh
->packet_dispatch
[SSH1_MSG_DEBUG
] = ssh1_msg_debug
;
5365 static void ssh1_protocol(Ssh ssh
, void *vin
, int inlen
,
5366 struct Packet
*pktin
)
5368 unsigned char *in
=(unsigned char*)vin
;
5369 if (ssh
->state
== SSH_STATE_CLOSED
)
5372 if (pktin
&& ssh
->packet_dispatch
[pktin
->type
]) {
5373 ssh
->packet_dispatch
[pktin
->type
](ssh
, pktin
);
5377 if (!ssh
->protocol_initial_phase_done
) {
5378 if (do_ssh1_login(ssh
, in
, inlen
, pktin
))
5379 ssh
->protocol_initial_phase_done
= TRUE
;
5384 do_ssh1_connection(ssh
, in
, inlen
, pktin
);
5388 * Utility routine for decoding comma-separated strings in KEXINIT.
5390 static int in_commasep_string(char *needle
, char *haystack
, int haylen
)
5393 if (!needle
|| !haystack
) /* protect against null pointers */
5395 needlen
= strlen(needle
);
5398 * Is it at the start of the string?
5400 if (haylen
>= needlen
&& /* haystack is long enough */
5401 !memcmp(needle
, haystack
, needlen
) && /* initial match */
5402 (haylen
== needlen
|| haystack
[needlen
] == ',')
5403 /* either , or EOS follows */
5407 * If not, search for the next comma and resume after that.
5408 * If no comma found, terminate.
5410 while (haylen
> 0 && *haystack
!= ',')
5411 haylen
--, haystack
++;
5414 haylen
--, haystack
++; /* skip over comma itself */
5419 * Similar routine for checking whether we have the first string in a list.
5421 static int first_in_commasep_string(char *needle
, char *haystack
, int haylen
)
5424 if (!needle
|| !haystack
) /* protect against null pointers */
5426 needlen
= strlen(needle
);
5428 * Is it at the start of the string?
5430 if (haylen
>= needlen
&& /* haystack is long enough */
5431 !memcmp(needle
, haystack
, needlen
) && /* initial match */
5432 (haylen
== needlen
|| haystack
[needlen
] == ',')
5433 /* either , or EOS follows */
5441 * SSH-2 key creation method.
5442 * (Currently assumes 2 lots of any hash are sufficient to generate
5443 * keys/IVs for any cipher/MAC. SSH2_MKKEY_ITERS documents this assumption.)
5445 #define SSH2_MKKEY_ITERS (2)
5446 static void ssh2_mkkey(Ssh ssh
, Bignum K
, unsigned char *H
, char chr
,
5447 unsigned char *keyspace
)
5449 const struct ssh_hash
*h
= ssh
->kex
->hash
;
5451 /* First hlen bytes. */
5453 if (!(ssh
->remote_bugs
& BUG_SSH2_DERIVEKEY
))
5454 hash_mpint(h
, s
, K
);
5455 h
->bytes(s
, H
, h
->hlen
);
5456 h
->bytes(s
, &chr
, 1);
5457 h
->bytes(s
, ssh
->v2_session_id
, ssh
->v2_session_id_len
);
5458 h
->final(s
, keyspace
);
5459 /* Next hlen bytes. */
5461 if (!(ssh
->remote_bugs
& BUG_SSH2_DERIVEKEY
))
5462 hash_mpint(h
, s
, K
);
5463 h
->bytes(s
, H
, h
->hlen
);
5464 h
->bytes(s
, keyspace
, h
->hlen
);
5465 h
->final(s
, keyspace
+ h
->hlen
);
5469 * Handle the SSH-2 transport layer.
5471 static void do_ssh2_transport(Ssh ssh
, void *vin
, int inlen
,
5472 struct Packet
*pktin
)
5474 unsigned char *in
= (unsigned char *)vin
;
5475 struct do_ssh2_transport_state
{
5477 int nbits
, pbits
, warn_kex
, warn_cscipher
, warn_sccipher
;
5478 Bignum p
, g
, e
, f
, K
;
5481 int kex_init_value
, kex_reply_value
;
5482 const struct ssh_mac
**maclist
;
5484 const struct ssh2_cipher
*cscipher_tobe
;
5485 const struct ssh2_cipher
*sccipher_tobe
;
5486 const struct ssh_mac
*csmac_tobe
;
5487 const struct ssh_mac
*scmac_tobe
;
5488 const struct ssh_compress
*cscomp_tobe
;
5489 const struct ssh_compress
*sccomp_tobe
;
5490 char *hostkeydata
, *sigdata
, *rsakeydata
, *keystr
, *fingerprint
;
5491 int hostkeylen
, siglen
, rsakeylen
;
5492 void *hkey
; /* actual host key */
5493 void *rsakey
; /* for RSA kex */
5494 unsigned char exchange_hash
[SSH2_KEX_MAX_HASH_LEN
];
5495 int n_preferred_kex
;
5496 const struct ssh_kexes
*preferred_kex
[KEX_MAX
];
5497 int n_preferred_ciphers
;
5498 const struct ssh2_ciphers
*preferred_ciphers
[CIPHER_MAX
];
5499 const struct ssh_compress
*preferred_comp
;
5500 int userauth_succeeded
; /* for delayed compression */
5501 int pending_compression
;
5502 int got_session_id
, activated_authconn
;
5503 struct Packet
*pktout
;
5508 crState(do_ssh2_transport_state
);
5512 s
->cscipher_tobe
= s
->sccipher_tobe
= NULL
;
5513 s
->csmac_tobe
= s
->scmac_tobe
= NULL
;
5514 s
->cscomp_tobe
= s
->sccomp_tobe
= NULL
;
5516 s
->got_session_id
= s
->activated_authconn
= FALSE
;
5517 s
->userauth_succeeded
= FALSE
;
5518 s
->pending_compression
= FALSE
;
5521 * Be prepared to work around the buggy MAC problem.
5523 if (ssh
->remote_bugs
& BUG_SSH2_HMAC
)
5524 s
->maclist
= buggymacs
, s
->nmacs
= lenof(buggymacs
);
5526 s
->maclist
= macs
, s
->nmacs
= lenof(macs
);
5529 ssh
->pkt_kctx
= SSH2_PKTCTX_NOKEX
;
5531 int i
, j
, k
, commalist_started
;
5534 * Set up the preferred key exchange. (NULL => warn below here)
5536 s
->n_preferred_kex
= 0;
5537 for (i
= 0; i
< KEX_MAX
; i
++) {
5538 switch (conf_get_int_int(ssh
->conf
, CONF_ssh_kexlist
, i
)) {
5540 s
->preferred_kex
[s
->n_preferred_kex
++] =
5541 &ssh_diffiehellman_gex
;
5544 s
->preferred_kex
[s
->n_preferred_kex
++] =
5545 &ssh_diffiehellman_group14
;
5548 s
->preferred_kex
[s
->n_preferred_kex
++] =
5549 &ssh_diffiehellman_group1
;
5552 s
->preferred_kex
[s
->n_preferred_kex
++] =
5556 /* Flag for later. Don't bother if it's the last in
5558 if (i
< KEX_MAX
- 1) {
5559 s
->preferred_kex
[s
->n_preferred_kex
++] = NULL
;
5566 * Set up the preferred ciphers. (NULL => warn below here)
5568 s
->n_preferred_ciphers
= 0;
5569 for (i
= 0; i
< CIPHER_MAX
; i
++) {
5570 switch (conf_get_int_int(ssh
->conf
, CONF_ssh_cipherlist
, i
)) {
5571 case CIPHER_BLOWFISH
:
5572 s
->preferred_ciphers
[s
->n_preferred_ciphers
++] = &ssh2_blowfish
;
5575 if (conf_get_int(ssh
->conf
, CONF_ssh2_des_cbc
)) {
5576 s
->preferred_ciphers
[s
->n_preferred_ciphers
++] = &ssh2_des
;
5580 s
->preferred_ciphers
[s
->n_preferred_ciphers
++] = &ssh2_3des
;
5583 s
->preferred_ciphers
[s
->n_preferred_ciphers
++] = &ssh2_aes
;
5585 case CIPHER_ARCFOUR
:
5586 s
->preferred_ciphers
[s
->n_preferred_ciphers
++] = &ssh2_arcfour
;
5589 /* Flag for later. Don't bother if it's the last in
5591 if (i
< CIPHER_MAX
- 1) {
5592 s
->preferred_ciphers
[s
->n_preferred_ciphers
++] = NULL
;
5599 * Set up preferred compression.
5601 if (conf_get_int(ssh
->conf
, CONF_compression
))
5602 s
->preferred_comp
= &ssh_zlib
;
5604 s
->preferred_comp
= &ssh_comp_none
;
5607 * Enable queueing of outgoing auth- or connection-layer
5608 * packets while we are in the middle of a key exchange.
5610 ssh
->queueing
= TRUE
;
5613 * Flag that KEX is in progress.
5615 ssh
->kex_in_progress
= TRUE
;
5618 * Construct and send our key exchange packet.
5620 s
->pktout
= ssh2_pkt_init(SSH2_MSG_KEXINIT
);
5621 for (i
= 0; i
< 16; i
++)
5622 ssh2_pkt_addbyte(s
->pktout
, (unsigned char) random_byte());
5623 /* List key exchange algorithms. */
5624 ssh2_pkt_addstring_start(s
->pktout
);
5625 commalist_started
= 0;
5626 for (i
= 0; i
< s
->n_preferred_kex
; i
++) {
5627 const struct ssh_kexes
*k
= s
->preferred_kex
[i
];
5628 if (!k
) continue; /* warning flag */
5629 for (j
= 0; j
< k
->nkexes
; j
++) {
5630 if (commalist_started
)
5631 ssh2_pkt_addstring_str(s
->pktout
, ",");
5632 ssh2_pkt_addstring_str(s
->pktout
, k
->list
[j
]->name
);
5633 commalist_started
= 1;
5636 /* List server host key algorithms. */
5637 ssh2_pkt_addstring_start(s
->pktout
);
5638 for (i
= 0; i
< lenof(hostkey_algs
); i
++) {
5639 ssh2_pkt_addstring_str(s
->pktout
, hostkey_algs
[i
]->name
);
5640 if (i
< lenof(hostkey_algs
) - 1)
5641 ssh2_pkt_addstring_str(s
->pktout
, ",");
5643 /* List encryption algorithms (client->server then server->client). */
5644 for (k
= 0; k
< 2; k
++) {
5645 ssh2_pkt_addstring_start(s
->pktout
);
5646 commalist_started
= 0;
5647 for (i
= 0; i
< s
->n_preferred_ciphers
; i
++) {
5648 const struct ssh2_ciphers
*c
= s
->preferred_ciphers
[i
];
5649 if (!c
) continue; /* warning flag */
5650 for (j
= 0; j
< c
->nciphers
; j
++) {
5651 if (commalist_started
)
5652 ssh2_pkt_addstring_str(s
->pktout
, ",");
5653 ssh2_pkt_addstring_str(s
->pktout
, c
->list
[j
]->name
);
5654 commalist_started
= 1;
5658 /* List MAC algorithms (client->server then server->client). */
5659 for (j
= 0; j
< 2; j
++) {
5660 ssh2_pkt_addstring_start(s
->pktout
);
5661 for (i
= 0; i
< s
->nmacs
; i
++) {
5662 ssh2_pkt_addstring_str(s
->pktout
, s
->maclist
[i
]->name
);
5663 if (i
< s
->nmacs
- 1)
5664 ssh2_pkt_addstring_str(s
->pktout
, ",");
5667 /* List client->server compression algorithms,
5668 * then server->client compression algorithms. (We use the
5669 * same set twice.) */
5670 for (j
= 0; j
< 2; j
++) {
5671 ssh2_pkt_addstring_start(s
->pktout
);
5672 assert(lenof(compressions
) > 1);
5673 /* Prefer non-delayed versions */
5674 ssh2_pkt_addstring_str(s
->pktout
, s
->preferred_comp
->name
);
5675 /* We don't even list delayed versions of algorithms until
5676 * they're allowed to be used, to avoid a race. See the end of
5678 if (s
->userauth_succeeded
&& s
->preferred_comp
->delayed_name
) {
5679 ssh2_pkt_addstring_str(s
->pktout
, ",");
5680 ssh2_pkt_addstring_str(s
->pktout
,
5681 s
->preferred_comp
->delayed_name
);
5683 for (i
= 0; i
< lenof(compressions
); i
++) {
5684 const struct ssh_compress
*c
= compressions
[i
];
5685 if (c
!= s
->preferred_comp
) {
5686 ssh2_pkt_addstring_str(s
->pktout
, ",");
5687 ssh2_pkt_addstring_str(s
->pktout
, c
->name
);
5688 if (s
->userauth_succeeded
&& c
->delayed_name
) {
5689 ssh2_pkt_addstring_str(s
->pktout
, ",");
5690 ssh2_pkt_addstring_str(s
->pktout
, c
->delayed_name
);
5695 /* List client->server languages. Empty list. */
5696 ssh2_pkt_addstring_start(s
->pktout
);
5697 /* List server->client languages. Empty list. */
5698 ssh2_pkt_addstring_start(s
->pktout
);
5699 /* First KEX packet does _not_ follow, because we're not that brave. */
5700 ssh2_pkt_addbool(s
->pktout
, FALSE
);
5702 ssh2_pkt_adduint32(s
->pktout
, 0);
5705 s
->our_kexinitlen
= s
->pktout
->length
- 5;
5706 s
->our_kexinit
= snewn(s
->our_kexinitlen
, unsigned char);
5707 memcpy(s
->our_kexinit
, s
->pktout
->data
+ 5, s
->our_kexinitlen
);
5709 ssh2_pkt_send_noqueue(ssh
, s
->pktout
);
5712 crWaitUntilV(pktin
);
5715 * Now examine the other side's KEXINIT to see what we're up
5719 char *str
, *preferred
;
5722 if (pktin
->type
!= SSH2_MSG_KEXINIT
) {
5723 bombout(("expected key exchange packet from server"));
5727 ssh
->hostkey
= NULL
;
5728 s
->cscipher_tobe
= NULL
;
5729 s
->sccipher_tobe
= NULL
;
5730 s
->csmac_tobe
= NULL
;
5731 s
->scmac_tobe
= NULL
;
5732 s
->cscomp_tobe
= NULL
;
5733 s
->sccomp_tobe
= NULL
;
5734 s
->warn_kex
= s
->warn_cscipher
= s
->warn_sccipher
= FALSE
;
5736 pktin
->savedpos
+= 16; /* skip garbage cookie */
5737 ssh_pkt_getstring(pktin
, &str
, &len
); /* key exchange algorithms */
5740 for (i
= 0; i
< s
->n_preferred_kex
; i
++) {
5741 const struct ssh_kexes
*k
= s
->preferred_kex
[i
];
5745 for (j
= 0; j
< k
->nkexes
; j
++) {
5746 if (!preferred
) preferred
= k
->list
[j
]->name
;
5747 if (in_commasep_string(k
->list
[j
]->name
, str
, len
)) {
5748 ssh
->kex
= k
->list
[j
];
5757 bombout(("Couldn't agree a key exchange algorithm (available: %s)",
5758 str ? str
: "(null)"));
5762 * Note that the server's guess is considered wrong if it doesn't match
5763 * the first algorithm in our list, even if it's still the algorithm
5766 s
->guessok
= first_in_commasep_string(preferred
, str
, len
);
5767 ssh_pkt_getstring(pktin
, &str
, &len
); /* host key algorithms */
5768 for (i
= 0; i
< lenof(hostkey_algs
); i
++) {
5769 if (in_commasep_string(hostkey_algs
[i
]->name
, str
, len
)) {
5770 ssh
->hostkey
= hostkey_algs
[i
];
5774 if (!ssh
->hostkey
) {
5775 bombout(("Couldn't agree a host key algorithm (available: %s)",
5776 str ? str
: "(null)"));
5780 s
->guessok
= s
->guessok
&&
5781 first_in_commasep_string(hostkey_algs
[0]->name
, str
, len
);
5782 ssh_pkt_getstring(pktin
, &str
, &len
); /* client->server cipher */
5783 for (i
= 0; i
< s
->n_preferred_ciphers
; i
++) {
5784 const struct ssh2_ciphers
*c
= s
->preferred_ciphers
[i
];
5786 s
->warn_cscipher
= TRUE
;
5788 for (j
= 0; j
< c
->nciphers
; j
++) {
5789 if (in_commasep_string(c
->list
[j
]->name
, str
, len
)) {
5790 s
->cscipher_tobe
= c
->list
[j
];
5795 if (s
->cscipher_tobe
)
5798 if (!s
->cscipher_tobe
) {
5799 bombout(("Couldn't agree a client-to-server cipher (available: %s)",
5800 str ? str
: "(null)"));
5804 ssh_pkt_getstring(pktin
, &str
, &len
); /* server->client cipher */
5805 for (i
= 0; i
< s
->n_preferred_ciphers
; i
++) {
5806 const struct ssh2_ciphers
*c
= s
->preferred_ciphers
[i
];
5808 s
->warn_sccipher
= TRUE
;
5810 for (j
= 0; j
< c
->nciphers
; j
++) {
5811 if (in_commasep_string(c
->list
[j
]->name
, str
, len
)) {
5812 s
->sccipher_tobe
= c
->list
[j
];
5817 if (s
->sccipher_tobe
)
5820 if (!s
->sccipher_tobe
) {
5821 bombout(("Couldn't agree a server-to-client cipher (available: %s)",
5822 str ? str
: "(null)"));
5826 ssh_pkt_getstring(pktin
, &str
, &len
); /* client->server mac */
5827 for (i
= 0; i
< s
->nmacs
; i
++) {
5828 if (in_commasep_string(s
->maclist
[i
]->name
, str
, len
)) {
5829 s
->csmac_tobe
= s
->maclist
[i
];
5833 ssh_pkt_getstring(pktin
, &str
, &len
); /* server->client mac */
5834 for (i
= 0; i
< s
->nmacs
; i
++) {
5835 if (in_commasep_string(s
->maclist
[i
]->name
, str
, len
)) {
5836 s
->scmac_tobe
= s
->maclist
[i
];
5840 ssh_pkt_getstring(pktin
, &str
, &len
); /* client->server compression */
5841 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
5842 const struct ssh_compress
*c
=
5843 i
== 0 ? s
->preferred_comp
: compressions
[i
- 1];
5844 if (in_commasep_string(c
->name
, str
, len
)) {
5847 } else if (in_commasep_string(c
->delayed_name
, str
, len
)) {
5848 if (s
->userauth_succeeded
) {
5852 s
->pending_compression
= TRUE
; /* try this later */
5856 ssh_pkt_getstring(pktin
, &str
, &len
); /* server->client compression */
5857 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
5858 const struct ssh_compress
*c
=
5859 i
== 0 ? s
->preferred_comp
: compressions
[i
- 1];
5860 if (in_commasep_string(c
->name
, str
, len
)) {
5863 } else if (in_commasep_string(c
->delayed_name
, str
, len
)) {
5864 if (s
->userauth_succeeded
) {
5868 s
->pending_compression
= TRUE
; /* try this later */
5872 if (s
->pending_compression
) {
5873 logevent("Server supports delayed compression; "
5874 "will try this later");
5876 ssh_pkt_getstring(pktin
, &str
, &len
); /* client->server language */
5877 ssh_pkt_getstring(pktin
, &str
, &len
); /* server->client language */
5878 s
->ignorepkt
= ssh2_pkt_getbool(pktin
) && !s
->guessok
;
5881 ssh_set_frozen(ssh
, 1);
5882 s
->dlgret
= askalg(ssh
->frontend
, "key-exchange algorithm",
5884 ssh_dialog_callback
, ssh
);
5885 if (s
->dlgret
< 0) {
5889 bombout(("Unexpected data from server while"
5890 " waiting for user response"));
5893 } while (pktin
|| inlen
> 0);
5894 s
->dlgret
= ssh
->user_response
;
5896 ssh_set_frozen(ssh
, 0);
5897 if (s
->dlgret
== 0) {
5898 ssh_disconnect(ssh
, "User aborted at kex warning", NULL
,
5904 if (s
->warn_cscipher
) {
5905 ssh_set_frozen(ssh
, 1);
5906 s
->dlgret
= askalg(ssh
->frontend
,
5907 "client-to-server cipher",
5908 s
->cscipher_tobe
->name
,
5909 ssh_dialog_callback
, ssh
);
5910 if (s
->dlgret
< 0) {
5914 bombout(("Unexpected data from server while"
5915 " waiting for user response"));
5918 } while (pktin
|| inlen
> 0);
5919 s
->dlgret
= ssh
->user_response
;
5921 ssh_set_frozen(ssh
, 0);
5922 if (s
->dlgret
== 0) {
5923 ssh_disconnect(ssh
, "User aborted at cipher warning", NULL
,
5929 if (s
->warn_sccipher
) {
5930 ssh_set_frozen(ssh
, 1);
5931 s
->dlgret
= askalg(ssh
->frontend
,
5932 "server-to-client cipher",
5933 s
->sccipher_tobe
->name
,
5934 ssh_dialog_callback
, ssh
);
5935 if (s
->dlgret
< 0) {
5939 bombout(("Unexpected data from server while"
5940 " waiting for user response"));
5943 } while (pktin
|| inlen
> 0);
5944 s
->dlgret
= ssh
->user_response
;
5946 ssh_set_frozen(ssh
, 0);
5947 if (s
->dlgret
== 0) {
5948 ssh_disconnect(ssh
, "User aborted at cipher warning", NULL
,
5954 ssh
->exhash
= ssh
->kex
->hash
->init();
5955 hash_string(ssh
->kex
->hash
, ssh
->exhash
, ssh
->v_c
, strlen(ssh
->v_c
));
5956 hash_string(ssh
->kex
->hash
, ssh
->exhash
, ssh
->v_s
, strlen(ssh
->v_s
));
5957 hash_string(ssh
->kex
->hash
, ssh
->exhash
,
5958 s
->our_kexinit
, s
->our_kexinitlen
);
5959 sfree(s
->our_kexinit
);
5960 if (pktin
->length
> 5)
5961 hash_string(ssh
->kex
->hash
, ssh
->exhash
,
5962 pktin
->data
+ 5, pktin
->length
- 5);
5964 if (s
->ignorepkt
) /* first_kex_packet_follows */
5965 crWaitUntilV(pktin
); /* Ignore packet */
5968 if (ssh
->kex
->main_type
== KEXTYPE_DH
) {
5970 * Work out the number of bits of key we will need from the
5971 * key exchange. We start with the maximum key length of
5977 csbits
= s
->cscipher_tobe
->keylen
;
5978 scbits
= s
->sccipher_tobe
->keylen
;
5979 s
->nbits
= (csbits
> scbits ? csbits
: scbits
);
5981 /* The keys only have hlen-bit entropy, since they're based on
5982 * a hash. So cap the key size at hlen bits. */
5983 if (s
->nbits
> ssh
->kex
->hash
->hlen
* 8)
5984 s
->nbits
= ssh
->kex
->hash
->hlen
* 8;
5987 * If we're doing Diffie-Hellman group exchange, start by
5988 * requesting a group.
5990 if (!ssh
->kex
->pdata
) {
5991 logevent("Doing Diffie-Hellman group exchange");
5992 ssh
->pkt_kctx
= SSH2_PKTCTX_DHGEX
;
5994 * Work out how big a DH group we will need to allow that
5997 s
->pbits
= 512 << ((s
->nbits
- 1) / 64);
5998 s
->pktout
= ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST
);
5999 ssh2_pkt_adduint32(s
->pktout
, s
->pbits
);
6000 ssh2_pkt_send_noqueue(ssh
, s
->pktout
);
6002 crWaitUntilV(pktin
);
6003 if (pktin
->type
!= SSH2_MSG_KEX_DH_GEX_GROUP
) {
6004 bombout(("expected key exchange group packet from server"));
6007 s
->p
= ssh2_pkt_getmp(pktin
);
6008 s
->g
= ssh2_pkt_getmp(pktin
);
6009 if (!s
->p
|| !s
->g
) {
6010 bombout(("unable to read mp-ints from incoming group packet"));
6013 ssh
->kex_ctx
= dh_setup_gex(s
->p
, s
->g
);
6014 s
->kex_init_value
= SSH2_MSG_KEX_DH_GEX_INIT
;
6015 s
->kex_reply_value
= SSH2_MSG_KEX_DH_GEX_REPLY
;
6017 ssh
->pkt_kctx
= SSH2_PKTCTX_DHGROUP
;
6018 ssh
->kex_ctx
= dh_setup_group(ssh
->kex
);
6019 s
->kex_init_value
= SSH2_MSG_KEXDH_INIT
;
6020 s
->kex_reply_value
= SSH2_MSG_KEXDH_REPLY
;
6021 logeventf(ssh
, "Using Diffie-Hellman with standard group \"%s\"",
6022 ssh
->kex
->groupname
);
6025 logeventf(ssh
, "Doing Diffie-Hellman key exchange with hash %s",
6026 ssh
->kex
->hash
->text_name
);
6028 * Now generate and send e for Diffie-Hellman.
6030 set_busy_status(ssh
->frontend
, BUSY_CPU
); /* this can take a while */
6031 s
->e
= dh_create_e(ssh
->kex_ctx
, s
->nbits
* 2);
6032 s
->pktout
= ssh2_pkt_init(s
->kex_init_value
);
6033 ssh2_pkt_addmp(s
->pktout
, s
->e
);
6034 ssh2_pkt_send_noqueue(ssh
, s
->pktout
);
6036 set_busy_status(ssh
->frontend
, BUSY_WAITING
); /* wait for server */
6037 crWaitUntilV(pktin
);
6038 if (pktin
->type
!= s
->kex_reply_value
) {
6039 bombout(("expected key exchange reply packet from server"));
6042 set_busy_status(ssh
->frontend
, BUSY_CPU
); /* cogitate */
6043 ssh_pkt_getstring(pktin
, &s
->hostkeydata
, &s
->hostkeylen
);
6044 s
->hkey
= ssh
->hostkey
->newkey(s
->hostkeydata
, s
->hostkeylen
);
6045 s
->f
= ssh2_pkt_getmp(pktin
);
6047 bombout(("unable to parse key exchange reply packet"));
6050 ssh_pkt_getstring(pktin
, &s
->sigdata
, &s
->siglen
);
6052 s
->K
= dh_find_K(ssh
->kex_ctx
, s
->f
);
6054 /* We assume everything from now on will be quick, and it might
6055 * involve user interaction. */
6056 set_busy_status(ssh
->frontend
, BUSY_NOT
);
6058 hash_string(ssh
->kex
->hash
, ssh
->exhash
, s
->hostkeydata
, s
->hostkeylen
);
6059 if (!ssh
->kex
->pdata
) {
6060 hash_uint32(ssh
->kex
->hash
, ssh
->exhash
, s
->pbits
);
6061 hash_mpint(ssh
->kex
->hash
, ssh
->exhash
, s
->p
);
6062 hash_mpint(ssh
->kex
->hash
, ssh
->exhash
, s
->g
);
6064 hash_mpint(ssh
->kex
->hash
, ssh
->exhash
, s
->e
);
6065 hash_mpint(ssh
->kex
->hash
, ssh
->exhash
, s
->f
);
6067 dh_cleanup(ssh
->kex_ctx
);
6069 if (!ssh
->kex
->pdata
) {
6074 logeventf(ssh
, "Doing RSA key exchange with hash %s",
6075 ssh
->kex
->hash
->text_name
);
6076 ssh
->pkt_kctx
= SSH2_PKTCTX_RSAKEX
;
6078 * RSA key exchange. First expect a KEXRSA_PUBKEY packet
6081 crWaitUntilV(pktin
);
6082 if (pktin
->type
!= SSH2_MSG_KEXRSA_PUBKEY
) {
6083 bombout(("expected RSA public key packet from server"));
6087 ssh_pkt_getstring(pktin
, &s
->hostkeydata
, &s
->hostkeylen
);
6088 hash_string(ssh
->kex
->hash
, ssh
->exhash
,
6089 s
->hostkeydata
, s
->hostkeylen
);
6090 s
->hkey
= ssh
->hostkey
->newkey(s
->hostkeydata
, s
->hostkeylen
);
6094 ssh_pkt_getstring(pktin
, &keydata
, &s
->rsakeylen
);
6095 s
->rsakeydata
= snewn(s
->rsakeylen
, char);
6096 memcpy(s
->rsakeydata
, keydata
, s
->rsakeylen
);
6099 s
->rsakey
= ssh_rsakex_newkey(s
->rsakeydata
, s
->rsakeylen
);
6101 sfree(s
->rsakeydata
);
6102 bombout(("unable to parse RSA public key from server"));
6106 hash_string(ssh
->kex
->hash
, ssh
->exhash
, s
->rsakeydata
, s
->rsakeylen
);
6109 * Next, set up a shared secret K, of precisely KLEN -
6110 * 2*HLEN - 49 bits, where KLEN is the bit length of the
6111 * RSA key modulus and HLEN is the bit length of the hash
6115 int klen
= ssh_rsakex_klen(s
->rsakey
);
6116 int nbits
= klen
- (2*ssh
->kex
->hash
->hlen
*8 + 49);
6118 unsigned char *kstr1
, *kstr2
, *outstr
;
6119 int kstr1len
, kstr2len
, outstrlen
;
6121 s
->K
= bn_power_2(nbits
- 1);
6123 for (i
= 0; i
< nbits
; i
++) {
6125 byte
= random_byte();
6127 bignum_set_bit(s
->K
, i
, (byte
>> (i
& 7)) & 1);
6131 * Encode this as an mpint.
6133 kstr1
= ssh2_mpint_fmt(s
->K
, &kstr1len
);
6134 kstr2
= snewn(kstr2len
= 4 + kstr1len
, unsigned char);
6135 PUT_32BIT(kstr2
, kstr1len
);
6136 memcpy(kstr2
+ 4, kstr1
, kstr1len
);
6139 * Encrypt it with the given RSA key.
6141 outstrlen
= (klen
+ 7) / 8;
6142 outstr
= snewn(outstrlen
, unsigned char);
6143 ssh_rsakex_encrypt(ssh
->kex
->hash
, kstr2
, kstr2len
,
6144 outstr
, outstrlen
, s
->rsakey
);
6147 * And send it off in a return packet.
6149 s
->pktout
= ssh2_pkt_init(SSH2_MSG_KEXRSA_SECRET
);
6150 ssh2_pkt_addstring_start(s
->pktout
);
6151 ssh2_pkt_addstring_data(s
->pktout
, (char *)outstr
, outstrlen
);
6152 ssh2_pkt_send_noqueue(ssh
, s
->pktout
);
6154 hash_string(ssh
->kex
->hash
, ssh
->exhash
, outstr
, outstrlen
);
6161 ssh_rsakex_freekey(s
->rsakey
);
6163 crWaitUntilV(pktin
);
6164 if (pktin
->type
!= SSH2_MSG_KEXRSA_DONE
) {
6165 sfree(s
->rsakeydata
);
6166 bombout(("expected signature packet from server"));
6170 ssh_pkt_getstring(pktin
, &s
->sigdata
, &s
->siglen
);
6172 sfree(s
->rsakeydata
);
6175 hash_mpint(ssh
->kex
->hash
, ssh
->exhash
, s
->K
);
6176 assert(ssh
->kex
->hash
->hlen
<= sizeof(s
->exchange_hash
));
6177 ssh
->kex
->hash
->final(ssh
->exhash
, s
->exchange_hash
);
6179 ssh
->kex_ctx
= NULL
;
6182 debug(("Exchange hash is:\n"));
6183 dmemdump(s
->exchange_hash
, ssh
->kex
->hash
->hlen
);
6187 !ssh
->hostkey
->verifysig(s
->hkey
, s
->sigdata
, s
->siglen
,
6188 (char *)s
->exchange_hash
,
6189 ssh
->kex
->hash
->hlen
)) {
6190 bombout(("Server's host key did not match the signature supplied"));
6195 * Authenticate remote host: verify host key. (We've already
6196 * checked the signature of the exchange hash.)
6198 s
->keystr
= ssh
->hostkey
->fmtkey(s
->hkey
);
6199 s
->fingerprint
= ssh
->hostkey
->fingerprint(s
->hkey
);
6200 ssh_set_frozen(ssh
, 1);
6201 s
->dlgret
= verify_ssh_host_key(ssh
->frontend
,
6202 ssh
->savedhost
, ssh
->savedport
,
6203 ssh
->hostkey
->keytype
, s
->keystr
,
6205 ssh_dialog_callback
, ssh
);
6206 if (s
->dlgret
< 0) {
6210 bombout(("Unexpected data from server while waiting"
6211 " for user host key response"));
6214 } while (pktin
|| inlen
> 0);
6215 s
->dlgret
= ssh
->user_response
;
6217 ssh_set_frozen(ssh
, 0);
6218 if (s
->dlgret
== 0) {
6219 ssh_disconnect(ssh
, "User aborted at host key verification", NULL
,
6223 if (!s
->got_session_id
) { /* don't bother logging this in rekeys */
6224 logevent("Host key fingerprint is:");
6225 logevent(s
->fingerprint
);
6227 sfree(s
->fingerprint
);
6229 ssh
->hostkey
->freekey(s
->hkey
);
6232 * The exchange hash from the very first key exchange is also
6233 * the session id, used in session key construction and
6236 if (!s
->got_session_id
) {
6237 assert(sizeof(s
->exchange_hash
) <= sizeof(ssh
->v2_session_id
));
6238 memcpy(ssh
->v2_session_id
, s
->exchange_hash
,
6239 sizeof(s
->exchange_hash
));
6240 ssh
->v2_session_id_len
= ssh
->kex
->hash
->hlen
;
6241 assert(ssh
->v2_session_id_len
<= sizeof(ssh
->v2_session_id
));
6242 s
->got_session_id
= TRUE
;
6246 * Send SSH2_MSG_NEWKEYS.
6248 s
->pktout
= ssh2_pkt_init(SSH2_MSG_NEWKEYS
);
6249 ssh2_pkt_send_noqueue(ssh
, s
->pktout
);
6250 ssh
->outgoing_data_size
= 0; /* start counting from here */
6253 * We've sent client NEWKEYS, so create and initialise
6254 * client-to-server session keys.
6256 if (ssh
->cs_cipher_ctx
)
6257 ssh
->cscipher
->free_context(ssh
->cs_cipher_ctx
);
6258 ssh
->cscipher
= s
->cscipher_tobe
;
6259 ssh
->cs_cipher_ctx
= ssh
->cscipher
->make_context();
6261 if (ssh
->cs_mac_ctx
)
6262 ssh
->csmac
->free_context(ssh
->cs_mac_ctx
);
6263 ssh
->csmac
= s
->csmac_tobe
;
6264 ssh
->cs_mac_ctx
= ssh
->csmac
->make_context();
6266 if (ssh
->cs_comp_ctx
)
6267 ssh
->cscomp
->compress_cleanup(ssh
->cs_comp_ctx
);
6268 ssh
->cscomp
= s
->cscomp_tobe
;
6269 ssh
->cs_comp_ctx
= ssh
->cscomp
->compress_init();
6272 * Set IVs on client-to-server keys. Here we use the exchange
6273 * hash from the _first_ key exchange.
6276 unsigned char keyspace
[SSH2_KEX_MAX_HASH_LEN
* SSH2_MKKEY_ITERS
];
6277 assert(sizeof(keyspace
) >= ssh
->kex
->hash
->hlen
* SSH2_MKKEY_ITERS
);
6278 ssh2_mkkey(ssh
,s
->K
,s
->exchange_hash
,'C',keyspace
);
6279 assert((ssh
->cscipher
->keylen
+7) / 8 <=
6280 ssh
->kex
->hash
->hlen
* SSH2_MKKEY_ITERS
);
6281 ssh
->cscipher
->setkey(ssh
->cs_cipher_ctx
, keyspace
);
6282 ssh2_mkkey(ssh
,s
->K
,s
->exchange_hash
,'A',keyspace
);
6283 assert(ssh
->cscipher
->blksize
<=
6284 ssh
->kex
->hash
->hlen
* SSH2_MKKEY_ITERS
);
6285 ssh
->cscipher
->setiv(ssh
->cs_cipher_ctx
, keyspace
);
6286 ssh2_mkkey(ssh
,s
->K
,s
->exchange_hash
,'E',keyspace
);
6287 assert(ssh
->csmac
->len
<=
6288 ssh
->kex
->hash
->hlen
* SSH2_MKKEY_ITERS
);
6289 ssh
->csmac
->setkey(ssh
->cs_mac_ctx
, keyspace
);
6290 smemclr(keyspace
, sizeof(keyspace
));
6293 logeventf(ssh
, "Initialised %.200s client->server encryption",
6294 ssh
->cscipher
->text_name
);
6295 logeventf(ssh
, "Initialised %.200s client->server MAC algorithm",
6296 ssh
->csmac
->text_name
);
6297 if (ssh
->cscomp
->text_name
)
6298 logeventf(ssh
, "Initialised %s compression",
6299 ssh
->cscomp
->text_name
);
6302 * Now our end of the key exchange is complete, we can send all
6303 * our queued higher-layer packets.
6305 ssh
->queueing
= FALSE
;
6306 ssh2_pkt_queuesend(ssh
);
6309 * Expect SSH2_MSG_NEWKEYS from server.
6311 crWaitUntilV(pktin
);
6312 if (pktin
->type
!= SSH2_MSG_NEWKEYS
) {
6313 bombout(("expected new-keys packet from server"));
6316 ssh
->incoming_data_size
= 0; /* start counting from here */
6319 * We've seen server NEWKEYS, so create and initialise
6320 * server-to-client session keys.
6322 if (ssh
->sc_cipher_ctx
)
6323 ssh
->sccipher
->free_context(ssh
->sc_cipher_ctx
);
6324 ssh
->sccipher
= s
->sccipher_tobe
;
6325 ssh
->sc_cipher_ctx
= ssh
->sccipher
->make_context();
6327 if (ssh
->sc_mac_ctx
)
6328 ssh
->scmac
->free_context(ssh
->sc_mac_ctx
);
6329 ssh
->scmac
= s
->scmac_tobe
;
6330 ssh
->sc_mac_ctx
= ssh
->scmac
->make_context();
6332 if (ssh
->sc_comp_ctx
)
6333 ssh
->sccomp
->decompress_cleanup(ssh
->sc_comp_ctx
);
6334 ssh
->sccomp
= s
->sccomp_tobe
;
6335 ssh
->sc_comp_ctx
= ssh
->sccomp
->decompress_init();
6338 * Set IVs on server-to-client keys. Here we use the exchange
6339 * hash from the _first_ key exchange.
6342 unsigned char keyspace
[SSH2_KEX_MAX_HASH_LEN
* SSH2_MKKEY_ITERS
];
6343 assert(sizeof(keyspace
) >= ssh
->kex
->hash
->hlen
* SSH2_MKKEY_ITERS
);
6344 ssh2_mkkey(ssh
,s
->K
,s
->exchange_hash
,'D',keyspace
);
6345 assert((ssh
->sccipher
->keylen
+7) / 8 <=
6346 ssh
->kex
->hash
->hlen
* SSH2_MKKEY_ITERS
);
6347 ssh
->sccipher
->setkey(ssh
->sc_cipher_ctx
, keyspace
);
6348 ssh2_mkkey(ssh
,s
->K
,s
->exchange_hash
,'B',keyspace
);
6349 assert(ssh
->sccipher
->blksize
<=
6350 ssh
->kex
->hash
->hlen
* SSH2_MKKEY_ITERS
);
6351 ssh
->sccipher
->setiv(ssh
->sc_cipher_ctx
, keyspace
);
6352 ssh2_mkkey(ssh
,s
->K
,s
->exchange_hash
,'F',keyspace
);
6353 assert(ssh
->scmac
->len
<=
6354 ssh
->kex
->hash
->hlen
* SSH2_MKKEY_ITERS
);
6355 ssh
->scmac
->setkey(ssh
->sc_mac_ctx
, keyspace
);
6356 smemclr(keyspace
, sizeof(keyspace
));
6358 logeventf(ssh
, "Initialised %.200s server->client encryption",
6359 ssh
->sccipher
->text_name
);
6360 logeventf(ssh
, "Initialised %.200s server->client MAC algorithm",
6361 ssh
->scmac
->text_name
);
6362 if (ssh
->sccomp
->text_name
)
6363 logeventf(ssh
, "Initialised %s decompression",
6364 ssh
->sccomp
->text_name
);
6367 * Free shared secret.
6372 * Key exchange is over. Loop straight back round if we have a
6373 * deferred rekey reason.
6375 if (ssh
->deferred_rekey_reason
) {
6376 logevent(ssh
->deferred_rekey_reason
);
6378 ssh
->deferred_rekey_reason
= NULL
;
6379 goto begin_key_exchange
;
6383 * Otherwise, schedule a timer for our next rekey.
6385 ssh
->kex_in_progress
= FALSE
;
6386 ssh
->last_rekey
= GETTICKCOUNT();
6387 if (conf_get_int(ssh
->conf
, CONF_ssh_rekey_time
) != 0)
6388 ssh
->next_rekey
= schedule_timer(conf_get_int(ssh
->conf
, CONF_ssh_rekey_time
)*60*TICKSPERSEC
,
6392 * Now we're encrypting. Begin returning 1 to the protocol main
6393 * function so that other things can run on top of the
6394 * transport. If we ever see a KEXINIT, we must go back to the
6397 * We _also_ go back to the start if we see pktin==NULL and
6398 * inlen negative, because this is a special signal meaning
6399 * `initiate client-driven rekey', and `in' contains a message
6400 * giving the reason for the rekey.
6402 * inlen==-1 means always initiate a rekey;
6403 * inlen==-2 means that userauth has completed successfully and
6404 * we should consider rekeying (for delayed compression).
6406 while (!((pktin
&& pktin
->type
== SSH2_MSG_KEXINIT
) ||
6407 (!pktin
&& inlen
< 0))) {
6409 if (!ssh
->protocol_initial_phase_done
) {
6410 ssh
->protocol_initial_phase_done
= TRUE
;
6412 * Allow authconn to initialise itself.
6414 do_ssh2_authconn(ssh
, NULL
, 0, NULL
);
6419 logevent("Server initiated key re-exchange");
6423 * authconn has seen a USERAUTH_SUCCEEDED. Time to enable
6424 * delayed compression, if it's available.
6426 * draft-miller-secsh-compression-delayed-00 says that you
6427 * negotiate delayed compression in the first key exchange, and
6428 * both sides start compressing when the server has sent
6429 * USERAUTH_SUCCESS. This has a race condition -- the server
6430 * can't know when the client has seen it, and thus which incoming
6431 * packets it should treat as compressed.
6433 * Instead, we do the initial key exchange without offering the
6434 * delayed methods, but note if the server offers them; when we
6435 * get here, if a delayed method was available that was higher
6436 * on our list than what we got, we initiate a rekey in which we
6437 * _do_ list the delayed methods (and hopefully get it as a
6438 * result). Subsequent rekeys will do the same.
6440 assert(!s
->userauth_succeeded
); /* should only happen once */
6441 s
->userauth_succeeded
= TRUE
;
6442 if (!s
->pending_compression
)
6443 /* Can't see any point rekeying. */
6444 goto wait_for_rekey
; /* this is utterly horrid */
6445 /* else fall through to rekey... */
6446 s
->pending_compression
= FALSE
;
6449 * Now we've decided to rekey.
6451 * Special case: if the server bug is set that doesn't
6452 * allow rekeying, we give a different log message and
6453 * continue waiting. (If such a server _initiates_ a rekey,
6454 * we process it anyway!)
6456 if ((ssh
->remote_bugs
& BUG_SSH2_REKEY
)) {
6457 logeventf(ssh
, "Server bug prevents key re-exchange (%s)",
6459 /* Reset the counters, so that at least this message doesn't
6460 * hit the event log _too_ often. */
6461 ssh
->outgoing_data_size
= 0;
6462 ssh
->incoming_data_size
= 0;
6463 if (conf_get_int(ssh
->conf
, CONF_ssh_rekey_time
) != 0) {
6465 schedule_timer(conf_get_int(ssh
->conf
, CONF_ssh_rekey_time
)*60*TICKSPERSEC
,
6468 goto wait_for_rekey
; /* this is still utterly horrid */
6470 logeventf(ssh
, "Initiating key re-exchange (%s)", (char *)in
);
6473 goto begin_key_exchange
;
6479 * Add data to an SSH-2 channel output buffer.
6481 static void ssh2_add_channel_data(struct ssh_channel
*c
, char *buf
,
6484 bufchain_add(&c
->v
.v2
.outbuffer
, buf
, len
);
6488 * Attempt to send data on an SSH-2 channel.
6490 static int ssh2_try_send(struct ssh_channel
*c
)
6493 struct Packet
*pktout
;
6496 while (c
->v
.v2
.remwindow
> 0 && bufchain_size(&c
->v
.v2
.outbuffer
) > 0) {
6499 bufchain_prefix(&c
->v
.v2
.outbuffer
, &data
, &len
);
6500 if ((unsigned)len
> c
->v
.v2
.remwindow
)
6501 len
= c
->v
.v2
.remwindow
;
6502 if ((unsigned)len
> c
->v
.v2
.remmaxpkt
)
6503 len
= c
->v
.v2
.remmaxpkt
;
6504 pktout
= ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA
);
6505 ssh2_pkt_adduint32(pktout
, c
->remoteid
);
6506 ssh2_pkt_addstring_start(pktout
);
6507 dont_log_data(ssh
, pktout
, PKTLOG_OMIT
);
6508 ssh2_pkt_addstring_data(pktout
, data
, len
);
6509 end_log_omission(ssh
, pktout
);
6510 ssh2_pkt_send(ssh
, pktout
);
6511 bufchain_consume(&c
->v
.v2
.outbuffer
, len
);
6512 c
->v
.v2
.remwindow
-= len
;
6516 * After having sent as much data as we can, return the amount
6519 ret
= bufchain_size(&c
->v
.v2
.outbuffer
);
6522 * And if there's no data pending but we need to send an EOF, send
6525 if (!ret
&& c
->pending_eof
)
6526 ssh_channel_try_eof(c
);
6531 static void ssh2_try_send_and_unthrottle(Ssh ssh
, struct ssh_channel
*c
)
6534 if (c
->closes
& CLOSES_SENT_EOF
)
6535 return; /* don't send on channels we've EOFed */
6536 bufsize
= ssh2_try_send(c
);
6539 case CHAN_MAINSESSION
:
6540 /* stdin need not receive an unthrottle
6541 * notification since it will be polled */
6544 x11_unthrottle(c
->u
.x11
.s
);
6547 /* agent sockets are request/response and need no
6548 * buffer management */
6551 pfd_unthrottle(c
->u
.pfd
.s
);
6558 * Set up most of a new ssh_channel for SSH-2.
6560 static void ssh2_channel_init(struct ssh_channel
*c
)
6563 c
->localid
= alloc_channel_id(ssh
);
6565 c
->pending_eof
= FALSE
;
6566 c
->throttling_conn
= FALSE
;
6567 c
->v
.v2
.locwindow
= c
->v
.v2
.locmaxwin
= c
->v
.v2
.remlocwin
=
6568 conf_get_int(ssh
->conf
, CONF_ssh_simple
) ? OUR_V2_BIGWIN
: OUR_V2_WINSIZE
;
6569 c
->v
.v2
.chanreq_head
= NULL
;
6570 c
->v
.v2
.throttle_state
= UNTHROTTLED
;
6571 bufchain_init(&c
->v
.v2
.outbuffer
);
6575 * CHANNEL_FAILURE doesn't come with any indication of what message
6576 * caused it, so we have to keep track of the outstanding
6577 * CHANNEL_REQUESTs ourselves.
6579 static void ssh2_queue_chanreq_handler(struct ssh_channel
*c
,
6580 cchandler_fn_t handler
, void *ctx
)
6582 struct outstanding_channel_request
*ocr
=
6583 snew(struct outstanding_channel_request
);
6585 assert(!(c
->closes
& (CLOSES_SENT_CLOSE
| CLOSES_RCVD_CLOSE
)));
6586 ocr
->handler
= handler
;
6589 if (!c
->v
.v2
.chanreq_head
)
6590 c
->v
.v2
.chanreq_head
= ocr
;
6592 c
->v
.v2
.chanreq_tail
->next
= ocr
;
6593 c
->v
.v2
.chanreq_tail
= ocr
;
6597 * Construct the common parts of a CHANNEL_REQUEST. If handler is not
6598 * NULL then a reply will be requested and the handler will be called
6599 * when it arrives. The returned packet is ready to have any
6600 * request-specific data added and be sent. Note that if a handler is
6601 * provided, it's essential that the request actually be sent.
6603 * The handler will usually be passed the response packet in pktin.
6604 * If pktin is NULL, this means that no reply will ever be forthcoming
6605 * (e.g. because the entire connection is being destroyed) and the
6606 * handler should free any storage it's holding.
6608 static struct Packet
*ssh2_chanreq_init(struct ssh_channel
*c
, char *type
,
6609 cchandler_fn_t handler
, void *ctx
)
6611 struct Packet
*pktout
;
6613 assert(!(c
->closes
& (CLOSES_SENT_CLOSE
| CLOSES_RCVD_CLOSE
)));
6614 pktout
= ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
6615 ssh2_pkt_adduint32(pktout
, c
->remoteid
);
6616 ssh2_pkt_addstring(pktout
, type
);
6617 ssh2_pkt_addbool(pktout
, handler
!= NULL
);
6618 if (handler
!= NULL
)
6619 ssh2_queue_chanreq_handler(c
, handler
, ctx
);
6624 * Potentially enlarge the window on an SSH-2 channel.
6626 static void ssh2_handle_winadj_response(struct ssh_channel
*, struct Packet
*,
6628 static void ssh2_set_window(struct ssh_channel
*c
, int newwin
)
6633 * Never send WINDOW_ADJUST for a channel that the remote side has
6634 * already sent EOF on; there's no point, since it won't be
6635 * sending any more data anyway. Ditto if _we've_ already sent
6638 if (c
->closes
& (CLOSES_RCVD_EOF
| CLOSES_SENT_CLOSE
))
6642 * If the remote end has a habit of ignoring maxpkt, limit the
6643 * window so that it has no choice (assuming it doesn't ignore the
6646 if ((ssh
->remote_bugs
& BUG_SSH2_MAXPKT
) && newwin
> OUR_V2_MAXPKT
)
6647 newwin
= OUR_V2_MAXPKT
;
6650 * Only send a WINDOW_ADJUST if there's significantly more window
6651 * available than the other end thinks there is. This saves us
6652 * sending a WINDOW_ADJUST for every character in a shell session.
6654 * "Significant" is arbitrarily defined as half the window size.
6656 if (newwin
/ 2 >= c
->v
.v2
.locwindow
) {
6657 struct Packet
*pktout
;
6661 * In order to keep track of how much window the client
6662 * actually has available, we'd like it to acknowledge each
6663 * WINDOW_ADJUST. We can't do that directly, so we accompany
6664 * it with a CHANNEL_REQUEST that has to be acknowledged.
6666 * This is only necessary if we're opening the window wide.
6667 * If we're not, then throughput is being constrained by
6668 * something other than the maximum window size anyway.
6670 if (newwin
== c
->v
.v2
.locmaxwin
&&
6671 !(ssh
->remote_bugs
& BUG_CHOKES_ON_WINADJ
)) {
6672 up
= snew(unsigned);
6673 *up
= newwin
- c
->v
.v2
.locwindow
;
6674 pktout
= ssh2_chanreq_init(c
, "winadj@putty.projects.tartarus.org",
6675 ssh2_handle_winadj_response
, up
);
6676 ssh2_pkt_send(ssh
, pktout
);
6678 if (c
->v
.v2
.throttle_state
!= UNTHROTTLED
)
6679 c
->v
.v2
.throttle_state
= UNTHROTTLING
;
6681 /* Pretend the WINDOW_ADJUST was acked immediately. */
6682 c
->v
.v2
.remlocwin
= newwin
;
6683 c
->v
.v2
.throttle_state
= THROTTLED
;
6685 pktout
= ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
6686 ssh2_pkt_adduint32(pktout
, c
->remoteid
);
6687 ssh2_pkt_adduint32(pktout
, newwin
- c
->v
.v2
.locwindow
);
6688 ssh2_pkt_send(ssh
, pktout
);
6689 c
->v
.v2
.locwindow
= newwin
;
6694 * Find the channel associated with a message. If there's no channel,
6695 * or it's not properly open, make a noise about it and return NULL.
6697 static struct ssh_channel
*ssh2_channel_msg(Ssh ssh
, struct Packet
*pktin
)
6699 unsigned localid
= ssh_pkt_getuint32(pktin
);
6700 struct ssh_channel
*c
;
6702 c
= find234(ssh
->channels
, &localid
, ssh_channelfind
);
6704 (c
->halfopen
&& pktin
->type
!= SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
&&
6705 pktin
->type
!= SSH2_MSG_CHANNEL_OPEN_FAILURE
)) {
6706 char *buf
= dupprintf("Received %s for %s channel %u",
6707 ssh2_pkt_type(ssh
->pkt_kctx
, ssh
->pkt_actx
,
6709 c ?
"half-open" : "nonexistent", localid
);
6710 ssh_disconnect(ssh
, NULL
, buf
, SSH2_DISCONNECT_PROTOCOL_ERROR
, FALSE
);
6717 static void ssh2_handle_winadj_response(struct ssh_channel
*c
,
6718 struct Packet
*pktin
, void *ctx
)
6720 unsigned *sizep
= ctx
;
6723 * Winadj responses should always be failures. However, at least
6724 * one server ("boks_sshd") is known to return SUCCESS for channel
6725 * requests it's never heard of, such as "winadj@putty". Raised
6726 * with foxt.com as bug 090916-090424, but for the sake of a quiet
6727 * life, we don't worry about what kind of response we got.
6730 c
->v
.v2
.remlocwin
+= *sizep
;
6733 * winadj messages are only sent when the window is fully open, so
6734 * if we get an ack of one, we know any pending unthrottle is
6737 if (c
->v
.v2
.throttle_state
== UNTHROTTLING
)
6738 c
->v
.v2
.throttle_state
= UNTHROTTLED
;
6741 static void ssh2_msg_channel_response(Ssh ssh
, struct Packet
*pktin
)
6743 struct ssh_channel
*c
= ssh2_channel_msg(ssh
, pktin
);
6744 struct outstanding_channel_request
*ocr
;
6747 ocr
= c
->v
.v2
.chanreq_head
;
6749 ssh2_msg_unexpected(ssh
, pktin
);
6752 ocr
->handler(c
, pktin
, ocr
->ctx
);
6753 c
->v
.v2
.chanreq_head
= ocr
->next
;
6756 * We may now initiate channel-closing procedures, if that
6757 * CHANNEL_REQUEST was the last thing outstanding before we send
6760 ssh2_channel_check_close(c
);
6763 static void ssh2_msg_channel_window_adjust(Ssh ssh
, struct Packet
*pktin
)
6765 struct ssh_channel
*c
;
6766 c
= ssh2_channel_msg(ssh
, pktin
);
6769 if (!(c
->closes
& CLOSES_SENT_EOF
)) {
6770 c
->v
.v2
.remwindow
+= ssh_pkt_getuint32(pktin
);
6771 ssh2_try_send_and_unthrottle(ssh
, c
);
6775 static void ssh2_msg_channel_data(Ssh ssh
, struct Packet
*pktin
)
6779 struct ssh_channel
*c
;
6780 c
= ssh2_channel_msg(ssh
, pktin
);
6783 if (pktin
->type
== SSH2_MSG_CHANNEL_EXTENDED_DATA
&&
6784 ssh_pkt_getuint32(pktin
) != SSH2_EXTENDED_DATA_STDERR
)
6785 return; /* extended but not stderr */
6786 ssh_pkt_getstring(pktin
, &data
, &length
);
6789 c
->v
.v2
.locwindow
-= length
;
6790 c
->v
.v2
.remlocwin
-= length
;
6792 case CHAN_MAINSESSION
:
6794 from_backend(ssh
->frontend
, pktin
->type
==
6795 SSH2_MSG_CHANNEL_EXTENDED_DATA
,
6799 bufsize
= x11_send(c
->u
.x11
.s
, data
, length
);
6802 bufsize
= pfd_send(c
->u
.pfd
.s
, data
, length
);
6805 while (length
> 0) {
6806 if (c
->u
.a
.lensofar
< 4) {
6807 unsigned int l
= min(4 - c
->u
.a
.lensofar
,
6809 memcpy(c
->u
.a
.msglen
+ c
->u
.a
.lensofar
,
6813 c
->u
.a
.lensofar
+= l
;
6815 if (c
->u
.a
.lensofar
== 4) {
6817 4 + GET_32BIT(c
->u
.a
.msglen
);
6818 c
->u
.a
.message
= snewn(c
->u
.a
.totallen
,
6820 memcpy(c
->u
.a
.message
, c
->u
.a
.msglen
, 4);
6822 if (c
->u
.a
.lensofar
>= 4 && length
> 0) {
6824 min(c
->u
.a
.totallen
- c
->u
.a
.lensofar
,
6826 memcpy(c
->u
.a
.message
+ c
->u
.a
.lensofar
,
6830 c
->u
.a
.lensofar
+= l
;
6832 if (c
->u
.a
.lensofar
== c
->u
.a
.totallen
) {
6835 if (agent_query(c
->u
.a
.message
,
6838 ssh_agentf_callback
, c
))
6839 ssh_agentf_callback(c
, reply
, replylen
);
6840 sfree(c
->u
.a
.message
);
6841 c
->u
.a
.message
= NULL
;
6842 c
->u
.a
.lensofar
= 0;
6849 * If it looks like the remote end hit the end of its window,
6850 * and we didn't want it to do that, think about using a
6853 if (c
->v
.v2
.remlocwin
<= 0 && c
->v
.v2
.throttle_state
== UNTHROTTLED
&&
6854 c
->v
.v2
.locmaxwin
< 0x40000000)
6855 c
->v
.v2
.locmaxwin
+= OUR_V2_WINSIZE
;
6857 * If we are not buffering too much data,
6858 * enlarge the window again at the remote side.
6859 * If we are buffering too much, we may still
6860 * need to adjust the window if the server's
6863 ssh2_set_window(c
, bufsize
< c
->v
.v2
.locmaxwin ?
6864 c
->v
.v2
.locmaxwin
- bufsize
: 0);
6866 * If we're either buffering way too much data, or if we're
6867 * buffering anything at all and we're in "simple" mode,
6868 * throttle the whole channel.
6870 if ((bufsize
> c
->v
.v2
.locmaxwin
||
6871 (conf_get_int(ssh
->conf
, CONF_ssh_simple
) && bufsize
> 0)) &&
6872 !c
->throttling_conn
) {
6873 c
->throttling_conn
= 1;
6874 ssh_throttle_conn(ssh
, +1);
6879 static void ssh_channel_destroy(struct ssh_channel
*c
)
6884 case CHAN_MAINSESSION
:
6885 ssh
->mainchan
= NULL
;
6886 update_specials_menu(ssh
->frontend
);
6889 if (c
->u
.x11
.s
!= NULL
)
6890 x11_close(c
->u
.x11
.s
);
6891 logevent("Forwarded X11 connection terminated");
6894 sfree(c
->u
.a
.message
);
6897 if (c
->u
.pfd
.s
!= NULL
)
6898 pfd_close(c
->u
.pfd
.s
);
6899 logevent("Forwarded port closed");
6903 del234(ssh
->channels
, c
);
6904 if (ssh
->version
== 2) {
6905 bufchain_clear(&c
->v
.v2
.outbuffer
);
6906 assert(c
->v
.v2
.chanreq_head
== NULL
);
6911 * See if that was the last channel left open.
6912 * (This is only our termination condition if we're
6913 * not running in -N mode.)
6915 if (ssh
->version
== 2 &&
6916 !conf_get_int(ssh
->conf
, CONF_ssh_no_shell
) &&
6917 count234(ssh
->channels
) == 0) {
6919 * We used to send SSH_MSG_DISCONNECT here,
6920 * because I'd believed that _every_ conforming
6921 * SSH-2 connection had to end with a disconnect
6922 * being sent by at least one side; apparently
6923 * I was wrong and it's perfectly OK to
6924 * unceremoniously slam the connection shut
6925 * when you're done, and indeed OpenSSH feels
6926 * this is more polite than sending a
6927 * DISCONNECT. So now we don't.
6929 ssh_disconnect(ssh
, "All channels closed", NULL
, 0, TRUE
);
6933 static void ssh2_channel_check_close(struct ssh_channel
*c
)
6936 struct Packet
*pktout
;
6938 if ((!((CLOSES_SENT_EOF
| CLOSES_RCVD_EOF
) & ~c
->closes
) ||
6939 c
->type
== CHAN_ZOMBIE
) &&
6940 !c
->v
.v2
.chanreq_head
&&
6941 !(c
->closes
& CLOSES_SENT_CLOSE
)) {
6943 * We have both sent and received EOF (or the channel is a
6944 * zombie), and we have no outstanding channel requests, which
6945 * means the channel is in final wind-up. But we haven't sent
6946 * CLOSE, so let's do so now.
6948 pktout
= ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE
);
6949 ssh2_pkt_adduint32(pktout
, c
->remoteid
);
6950 ssh2_pkt_send(ssh
, pktout
);
6951 c
->closes
|= CLOSES_SENT_EOF
| CLOSES_SENT_CLOSE
;
6954 if (!((CLOSES_SENT_CLOSE
| CLOSES_RCVD_CLOSE
) & ~c
->closes
)) {
6955 assert(c
->v
.v2
.chanreq_head
== NULL
);
6957 * We have both sent and received CLOSE, which means we're
6958 * completely done with the channel.
6960 ssh_channel_destroy(c
);
6964 static void ssh2_channel_got_eof(struct ssh_channel
*c
)
6966 if (c
->closes
& CLOSES_RCVD_EOF
)
6967 return; /* already seen EOF */
6968 c
->closes
|= CLOSES_RCVD_EOF
;
6970 if (c
->type
== CHAN_X11
) {
6971 x11_send_eof(c
->u
.x11
.s
);
6972 } else if (c
->type
== CHAN_AGENT
) {
6973 /* Manufacture an outgoing EOF in response to the incoming one. */
6974 sshfwd_write_eof(c
);
6975 } else if (c
->type
== CHAN_SOCKDATA
) {
6976 pfd_send_eof(c
->u
.pfd
.s
);
6977 } else if (c
->type
== CHAN_MAINSESSION
) {
6980 if (!ssh
->sent_console_eof
&&
6981 (from_backend_eof(ssh
->frontend
) || ssh
->got_pty
)) {
6983 * Either from_backend_eof told us that the front end
6984 * wants us to close the outgoing side of the connection
6985 * as soon as we see EOF from the far end, or else we've
6986 * unilaterally decided to do that because we've allocated
6987 * a remote pty and hence EOF isn't a particularly
6988 * meaningful concept.
6990 sshfwd_write_eof(c
);
6992 ssh
->sent_console_eof
= TRUE
;
6995 ssh2_channel_check_close(c
);
6998 static void ssh2_msg_channel_eof(Ssh ssh
, struct Packet
*pktin
)
7000 struct ssh_channel
*c
;
7002 c
= ssh2_channel_msg(ssh
, pktin
);
7005 ssh2_channel_got_eof(c
);
7008 static void ssh2_msg_channel_close(Ssh ssh
, struct Packet
*pktin
)
7010 struct ssh_channel
*c
;
7012 c
= ssh2_channel_msg(ssh
, pktin
);
7017 * When we receive CLOSE on a channel, we assume it comes with an
7018 * implied EOF if we haven't seen EOF yet.
7020 ssh2_channel_got_eof(c
);
7023 * And we also send an outgoing EOF, if we haven't already, on the
7024 * assumption that CLOSE is a pretty forceful announcement that
7025 * the remote side is doing away with the entire channel. (If it
7026 * had wanted to send us EOF and continue receiving data from us,
7027 * it would have just sent CHANNEL_EOF.)
7029 if (!(c
->closes
& CLOSES_SENT_EOF
)) {
7031 * Make sure we don't read any more from whatever our local
7032 * data source is for this channel.
7035 case CHAN_MAINSESSION
:
7036 ssh
->send_ok
= 0; /* stop trying to read from stdin */
7039 x11_override_throttle(c
->u
.x11
.s
, 1);
7042 pfd_override_throttle(c
->u
.pfd
.s
, 1);
7047 * Send outgoing EOF.
7049 sshfwd_write_eof(c
);
7053 * Now process the actual close.
7055 if (!(c
->closes
& CLOSES_RCVD_CLOSE
)) {
7056 c
->closes
|= CLOSES_RCVD_CLOSE
;
7057 ssh2_channel_check_close(c
);
7061 static void ssh2_msg_channel_open_confirmation(Ssh ssh
, struct Packet
*pktin
)
7063 struct ssh_channel
*c
;
7065 c
= ssh2_channel_msg(ssh
, pktin
);
7068 if (c
->type
!= CHAN_SOCKDATA_DORMANT
)
7069 return; /* dunno why they're confirming this */
7070 c
->remoteid
= ssh_pkt_getuint32(pktin
);
7071 c
->halfopen
= FALSE
;
7072 c
->type
= CHAN_SOCKDATA
;
7073 c
->v
.v2
.remwindow
= ssh_pkt_getuint32(pktin
);
7074 c
->v
.v2
.remmaxpkt
= ssh_pkt_getuint32(pktin
);
7076 pfd_confirm(c
->u
.pfd
.s
);
7078 ssh_channel_try_eof(c
);
7081 static void ssh2_msg_channel_open_failure(Ssh ssh
, struct Packet
*pktin
)
7083 static const char *const reasons
[] = {
7084 "<unknown reason code>",
7085 "Administratively prohibited",
7087 "Unknown channel type",
7088 "Resource shortage",
7090 unsigned reason_code
;
7091 char *reason_string
;
7093 struct ssh_channel
*c
;
7094 c
= ssh2_channel_msg(ssh
, pktin
);
7097 if (c
->type
!= CHAN_SOCKDATA_DORMANT
)
7098 return; /* dunno why they're failing this */
7100 reason_code
= ssh_pkt_getuint32(pktin
);
7101 if (reason_code
>= lenof(reasons
))
7102 reason_code
= 0; /* ensure reasons[reason_code] in range */
7103 ssh_pkt_getstring(pktin
, &reason_string
, &reason_length
);
7104 logeventf(ssh
, "Forwarded connection refused by server: %s [%.*s]",
7105 reasons
[reason_code
], reason_length
, reason_string
);
7107 pfd_close(c
->u
.pfd
.s
);
7109 del234(ssh
->channels
, c
);
7113 static void ssh2_msg_channel_request(Ssh ssh
, struct Packet
*pktin
)
7116 int typelen
, want_reply
;
7117 int reply
= SSH2_MSG_CHANNEL_FAILURE
; /* default */
7118 struct ssh_channel
*c
;
7119 struct Packet
*pktout
;
7121 c
= ssh2_channel_msg(ssh
, pktin
);
7124 ssh_pkt_getstring(pktin
, &type
, &typelen
);
7125 want_reply
= ssh2_pkt_getbool(pktin
);
7128 * Having got the channel number, we now look at
7129 * the request type string to see if it's something
7132 if (c
== ssh
->mainchan
) {
7134 * We recognise "exit-status" and "exit-signal" on
7135 * the primary channel.
7137 if (typelen
== 11 &&
7138 !memcmp(type
, "exit-status", 11)) {
7140 ssh
->exitcode
= ssh_pkt_getuint32(pktin
);
7141 logeventf(ssh
, "Server sent command exit status %d",
7143 reply
= SSH2_MSG_CHANNEL_SUCCESS
;
7145 } else if (typelen
== 11 &&
7146 !memcmp(type
, "exit-signal", 11)) {
7148 int is_plausible
= TRUE
, is_int
= FALSE
;
7149 char *fmt_sig
= "", *fmt_msg
= "";
7151 int msglen
= 0, core
= FALSE
;
7152 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
7153 * provide an `int' for the signal, despite its
7154 * having been a `string' in the drafts of RFC 4254 since at
7155 * least 2001. (Fixed in session.c 1.147.) Try to
7156 * infer which we can safely parse it as. */
7158 unsigned char *p
= pktin
->body
+
7160 long len
= pktin
->length
- pktin
->savedpos
;
7161 unsigned long num
= GET_32BIT(p
); /* what is it? */
7162 /* If it's 0, it hardly matters; assume string */
7166 int maybe_int
= FALSE
, maybe_str
= FALSE
;
7167 #define CHECK_HYPOTHESIS(offset, result) \
7170 if (q >= 0 && q+4 <= len) { \
7171 q = q + 4 + GET_32BIT(p+q); \
7172 if (q >= 0 && q+4 <= len && \
7173 ((q = q + 4 + GET_32BIT(p+q))!= 0) && q == len) \
7177 CHECK_HYPOTHESIS(4+1, maybe_int
);
7178 CHECK_HYPOTHESIS(4+num
+1, maybe_str
);
7179 #undef CHECK_HYPOTHESIS
7180 if (maybe_int
&& !maybe_str
)
7182 else if (!maybe_int
&& maybe_str
)
7185 /* Crikey. Either or neither. Panic. */
7186 is_plausible
= FALSE
;
7189 ssh
->exitcode
= 128; /* means `unknown signal' */
7192 /* Old non-standard OpenSSH. */
7193 int signum
= ssh_pkt_getuint32(pktin
);
7194 fmt_sig
= dupprintf(" %d", signum
);
7195 ssh
->exitcode
= 128 + signum
;
7197 /* As per RFC 4254. */
7200 ssh_pkt_getstring(pktin
, &sig
, &siglen
);
7201 /* Signal name isn't supposed to be blank, but
7202 * let's cope gracefully if it is. */
7204 fmt_sig
= dupprintf(" \"%.*s\"",
7209 * Really hideous method of translating the
7210 * signal description back into a locally
7211 * meaningful number.
7216 #define TRANSLATE_SIGNAL(s) \
7217 else if (siglen == lenof(#s)-1 && !memcmp(sig, #s, siglen)) \
7218 ssh->exitcode = 128 + SIG ## s
7220 TRANSLATE_SIGNAL(ABRT
);
7223 TRANSLATE_SIGNAL(ALRM
);
7226 TRANSLATE_SIGNAL(FPE
);
7229 TRANSLATE_SIGNAL(HUP
);
7232 TRANSLATE_SIGNAL(ILL
);
7235 TRANSLATE_SIGNAL(INT
);
7238 TRANSLATE_SIGNAL(KILL
);
7241 TRANSLATE_SIGNAL(PIPE
);
7244 TRANSLATE_SIGNAL(QUIT
);
7247 TRANSLATE_SIGNAL(SEGV
);
7250 TRANSLATE_SIGNAL(TERM
);
7253 TRANSLATE_SIGNAL(USR1
);
7256 TRANSLATE_SIGNAL(USR2
);
7258 #undef TRANSLATE_SIGNAL
7260 ssh
->exitcode
= 128;
7262 core
= ssh2_pkt_getbool(pktin
);
7263 ssh_pkt_getstring(pktin
, &msg
, &msglen
);
7265 fmt_msg
= dupprintf(" (\"%.*s\")", msglen
, msg
);
7267 /* ignore lang tag */
7268 } /* else don't attempt to parse */
7269 logeventf(ssh
, "Server exited on signal%s%s%s",
7270 fmt_sig
, core ?
" (core dumped)" : "",
7272 if (*fmt_sig
) sfree(fmt_sig
);
7273 if (*fmt_msg
) sfree(fmt_msg
);
7274 reply
= SSH2_MSG_CHANNEL_SUCCESS
;
7279 * This is a channel request we don't know
7280 * about, so we now either ignore the request
7281 * or respond with CHANNEL_FAILURE, depending
7284 reply
= SSH2_MSG_CHANNEL_FAILURE
;
7287 pktout
= ssh2_pkt_init(reply
);
7288 ssh2_pkt_adduint32(pktout
, c
->remoteid
);
7289 ssh2_pkt_send(ssh
, pktout
);
7293 static void ssh2_msg_global_request(Ssh ssh
, struct Packet
*pktin
)
7296 int typelen
, want_reply
;
7297 struct Packet
*pktout
;
7299 ssh_pkt_getstring(pktin
, &type
, &typelen
);
7300 want_reply
= ssh2_pkt_getbool(pktin
);
7303 * We currently don't support any global requests
7304 * at all, so we either ignore the request or
7305 * respond with REQUEST_FAILURE, depending on
7309 pktout
= ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE
);
7310 ssh2_pkt_send(ssh
, pktout
);
7314 static void ssh2_msg_channel_open(Ssh ssh
, struct Packet
*pktin
)
7322 struct ssh_channel
*c
;
7323 unsigned remid
, winsize
, pktsize
;
7324 struct Packet
*pktout
;
7326 ssh_pkt_getstring(pktin
, &type
, &typelen
);
7327 c
= snew(struct ssh_channel
);
7330 remid
= ssh_pkt_getuint32(pktin
);
7331 winsize
= ssh_pkt_getuint32(pktin
);
7332 pktsize
= ssh_pkt_getuint32(pktin
);
7334 if (typelen
== 3 && !memcmp(type
, "x11", 3)) {
7338 ssh_pkt_getstring(pktin
, &peeraddr
, &peeraddrlen
);
7339 addrstr
= snewn(peeraddrlen
+1, char);
7340 memcpy(addrstr
, peeraddr
, peeraddrlen
);
7341 addrstr
[peeraddrlen
] = '\0';
7342 peerport
= ssh_pkt_getuint32(pktin
);
7344 logeventf(ssh
, "Received X11 connect request from %s:%d",
7347 if (!ssh
->X11_fwd_enabled
)
7348 error
= "X11 forwarding is not enabled";
7349 else if ((x11err
= x11_init(&c
->u
.x11
.s
, ssh
->x11disp
, c
,
7350 addrstr
, peerport
, ssh
->conf
)) != NULL
) {
7351 logeventf(ssh
, "Local X11 connection failed: %s", x11err
);
7352 error
= "Unable to open an X11 connection";
7354 logevent("Opening X11 forward connection succeeded");
7359 } else if (typelen
== 15 &&
7360 !memcmp(type
, "forwarded-tcpip", 15)) {
7361 struct ssh_rportfwd pf
, *realpf
;
7364 ssh_pkt_getstring(pktin
, &dummy
, &dummylen
);/* skip address */
7365 pf
.sport
= ssh_pkt_getuint32(pktin
);
7366 ssh_pkt_getstring(pktin
, &peeraddr
, &peeraddrlen
);
7367 peerport
= ssh_pkt_getuint32(pktin
);
7368 realpf
= find234(ssh
->rportfwds
, &pf
, NULL
);
7369 logeventf(ssh
, "Received remote port %d open request "
7370 "from %s:%d", pf
.sport
, peeraddr
, peerport
);
7371 if (realpf
== NULL
) {
7372 error
= "Remote port is not recognised";
7374 const char *e
= pfd_newconnect(&c
->u
.pfd
.s
,
7378 realpf
->pfrec
->addressfamily
);
7379 logeventf(ssh
, "Attempting to forward remote port to "
7380 "%s:%d", realpf
->dhost
, realpf
->dport
);
7382 logeventf(ssh
, "Port open failed: %s", e
);
7383 error
= "Port open failed";
7385 logevent("Forwarded port opened successfully");
7386 c
->type
= CHAN_SOCKDATA
;
7389 } else if (typelen
== 22 &&
7390 !memcmp(type
, "auth-agent@openssh.com", 22)) {
7391 if (!ssh
->agentfwd_enabled
)
7392 error
= "Agent forwarding is not enabled";
7394 c
->type
= CHAN_AGENT
; /* identify channel type */
7395 c
->u
.a
.lensofar
= 0;
7398 error
= "Unsupported channel type requested";
7401 c
->remoteid
= remid
;
7402 c
->halfopen
= FALSE
;
7404 pktout
= ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE
);
7405 ssh2_pkt_adduint32(pktout
, c
->remoteid
);
7406 ssh2_pkt_adduint32(pktout
, SSH2_OPEN_CONNECT_FAILED
);
7407 ssh2_pkt_addstring(pktout
, error
);
7408 ssh2_pkt_addstring(pktout
, "en"); /* language tag */
7409 ssh2_pkt_send(ssh
, pktout
);
7410 logeventf(ssh
, "Rejected channel open: %s", error
);
7413 ssh2_channel_init(c
);
7414 c
->v
.v2
.remwindow
= winsize
;
7415 c
->v
.v2
.remmaxpkt
= pktsize
;
7416 add234(ssh
->channels
, c
);
7417 pktout
= ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
);
7418 ssh2_pkt_adduint32(pktout
, c
->remoteid
);
7419 ssh2_pkt_adduint32(pktout
, c
->localid
);
7420 ssh2_pkt_adduint32(pktout
, c
->v
.v2
.locwindow
);
7421 ssh2_pkt_adduint32(pktout
, OUR_V2_MAXPKT
); /* our max pkt size */
7422 ssh2_pkt_send(ssh
, pktout
);
7427 * Buffer banner messages for later display at some convenient point,
7428 * if we're going to display them.
7430 static void ssh2_msg_userauth_banner(Ssh ssh
, struct Packet
*pktin
)
7432 /* Arbitrary limit to prevent unbounded inflation of buffer */
7433 if (conf_get_int(ssh
->conf
, CONF_ssh_show_banner
) &&
7434 bufchain_size(&ssh
->banner
) <= 131072) {
7435 char *banner
= NULL
;
7437 ssh_pkt_getstring(pktin
, &banner
, &size
);
7439 bufchain_add(&ssh
->banner
, banner
, size
);
7443 /* Helper function to deal with sending tty modes for "pty-req" */
7444 static void ssh2_send_ttymode(void *data
, char *mode
, char *val
)
7446 struct Packet
*pktout
= (struct Packet
*)data
;
7448 unsigned int arg
= 0;
7449 while (strcmp(mode
, ssh_ttymodes
[i
].mode
) != 0) i
++;
7450 if (i
== lenof(ssh_ttymodes
)) return;
7451 switch (ssh_ttymodes
[i
].type
) {
7453 arg
= ssh_tty_parse_specchar(val
);
7456 arg
= ssh_tty_parse_boolean(val
);
7459 ssh2_pkt_addbyte(pktout
, ssh_ttymodes
[i
].opcode
);
7460 ssh2_pkt_adduint32(pktout
, arg
);
7463 static void ssh2_setup_x11(struct ssh_channel
*c
, struct Packet
*pktin
,
7466 struct ssh2_setup_x11_state
{
7470 struct Packet
*pktout
;
7471 crStateP(ssh2_setup_x11_state
, ctx
);
7475 logevent("Requesting X11 forwarding");
7476 pktout
= ssh2_chanreq_init(ssh
->mainchan
, "x11-req",
7478 ssh2_pkt_addbool(pktout
, 0); /* many connections */
7479 ssh2_pkt_addstring(pktout
, ssh
->x11disp
->remoteauthprotoname
);
7481 * Note that while we blank the X authentication data here, we don't
7482 * take any special action to blank the start of an X11 channel,
7483 * so using MIT-MAGIC-COOKIE-1 and actually opening an X connection
7484 * without having session blanking enabled is likely to leak your
7485 * cookie into the log.
7487 dont_log_password(ssh
, pktout
, PKTLOG_BLANK
);
7488 ssh2_pkt_addstring(pktout
, ssh
->x11disp
->remoteauthdatastring
);
7489 end_log_omission(ssh
, pktout
);
7490 ssh2_pkt_adduint32(pktout
, ssh
->x11disp
->screennum
);
7491 ssh2_pkt_send(ssh
, pktout
);
7493 crWaitUntilV(pktin
);
7496 if (pktin
->type
== SSH2_MSG_CHANNEL_SUCCESS
) {
7497 logevent("X11 forwarding enabled");
7498 ssh
->X11_fwd_enabled
= TRUE
;
7500 logevent("X11 forwarding refused");
7506 static void ssh2_setup_agent(struct ssh_channel
*c
, struct Packet
*pktin
,
7509 struct ssh2_setup_agent_state
{
7513 struct Packet
*pktout
;
7514 crStateP(ssh2_setup_agent_state
, ctx
);
7518 logevent("Requesting OpenSSH-style agent forwarding");
7519 pktout
= ssh2_chanreq_init(ssh
->mainchan
, "auth-agent-req@openssh.com",
7520 ssh2_setup_agent
, s
);
7521 ssh2_pkt_send(ssh
, pktout
);
7523 crWaitUntilV(pktin
);
7526 if (pktin
->type
== SSH2_MSG_CHANNEL_SUCCESS
) {
7527 logevent("Agent forwarding enabled");
7528 ssh
->agentfwd_enabled
= TRUE
;
7530 logevent("Agent forwarding refused");
7536 static void ssh2_setup_pty(struct ssh_channel
*c
, struct Packet
*pktin
,
7539 struct ssh2_setup_pty_state
{
7543 struct Packet
*pktout
;
7544 crStateP(ssh2_setup_pty_state
, ctx
);
7548 /* Unpick the terminal-speed string. */
7549 /* XXX perhaps we should allow no speeds to be sent. */
7550 ssh
->ospeed
= 38400; ssh
->ispeed
= 38400; /* last-resort defaults */
7551 sscanf(conf_get_str(ssh
->conf
, CONF_termspeed
), "%d,%d", &ssh
->ospeed
, &ssh
->ispeed
);
7552 /* Build the pty request. */
7553 pktout
= ssh2_chanreq_init(ssh
->mainchan
, "pty-req",
7555 ssh2_pkt_addstring(pktout
, conf_get_str(ssh
->conf
, CONF_termtype
));
7556 ssh2_pkt_adduint32(pktout
, ssh
->term_width
);
7557 ssh2_pkt_adduint32(pktout
, ssh
->term_height
);
7558 ssh2_pkt_adduint32(pktout
, 0); /* pixel width */
7559 ssh2_pkt_adduint32(pktout
, 0); /* pixel height */
7560 ssh2_pkt_addstring_start(pktout
);
7561 parse_ttymodes(ssh
, ssh2_send_ttymode
, (void *)pktout
);
7562 ssh2_pkt_addbyte(pktout
, SSH2_TTY_OP_ISPEED
);
7563 ssh2_pkt_adduint32(pktout
, ssh
->ispeed
);
7564 ssh2_pkt_addbyte(pktout
, SSH2_TTY_OP_OSPEED
);
7565 ssh2_pkt_adduint32(pktout
, ssh
->ospeed
);
7566 ssh2_pkt_addstring_data(pktout
, "\0", 1); /* TTY_OP_END */
7567 ssh2_pkt_send(ssh
, pktout
);
7568 ssh
->state
= SSH_STATE_INTERMED
;
7570 crWaitUntilV(pktin
);
7573 if (pktin
->type
== SSH2_MSG_CHANNEL_SUCCESS
) {
7574 logeventf(ssh
, "Allocated pty (ospeed %dbps, ispeed %dbps)",
7575 ssh
->ospeed
, ssh
->ispeed
);
7576 ssh
->got_pty
= TRUE
;
7578 c_write_str(ssh
, "Server refused to allocate pty\r\n");
7579 ssh
->editing
= ssh
->echoing
= 1;
7586 static void ssh2_setup_env(struct ssh_channel
*c
, struct Packet
*pktin
,
7589 struct ssh2_setup_env_state
{
7591 int num_env
, env_left
, env_ok
;
7594 struct Packet
*pktout
;
7595 crStateP(ssh2_setup_env_state
, ctx
);
7600 * Send environment variables.
7602 * Simplest thing here is to send all the requests at once, and
7603 * then wait for a whole bunch of successes or failures.
7609 for (val
= conf_get_str_strs(ssh
->conf
, CONF_environmt
, NULL
, &key
);
7611 val
= conf_get_str_strs(ssh
->conf
, CONF_environmt
, key
, &key
)) {
7612 pktout
= ssh2_chanreq_init(ssh
->mainchan
, "env", ssh2_setup_env
, s
);
7613 ssh2_pkt_addstring(pktout
, key
);
7614 ssh2_pkt_addstring(pktout
, val
);
7615 ssh2_pkt_send(ssh
, pktout
);
7620 logeventf(ssh
, "Sent %d environment variables", s
->num_env
);
7625 s
->env_left
= s
->num_env
;
7627 while (s
->env_left
> 0) {
7628 crWaitUntilV(pktin
);
7629 if (!pktin
) goto out
;
7630 if (pktin
->type
== SSH2_MSG_CHANNEL_SUCCESS
)
7635 if (s
->env_ok
== s
->num_env
) {
7636 logevent("All environment variables successfully set");
7637 } else if (s
->env_ok
== 0) {
7638 logevent("All environment variables refused");
7639 c_write_str(ssh
, "Server refused to set environment variables\r\n");
7641 logeventf(ssh
, "%d environment variables refused",
7642 s
->num_env
- s
->env_ok
);
7643 c_write_str(ssh
, "Server refused to set all environment variables\r\n");
7651 * Handle the SSH-2 userauth and connection layers.
7653 static void ssh2_msg_authconn(Ssh ssh
, struct Packet
*pktin
)
7655 do_ssh2_authconn(ssh
, NULL
, 0, pktin
);
7658 static void ssh2_response_authconn(struct ssh_channel
*c
, struct Packet
*pktin
,
7661 do_ssh2_authconn(c
->ssh
, NULL
, 0, pktin
);
7664 static void do_ssh2_authconn(Ssh ssh
, unsigned char *in
, int inlen
,
7665 struct Packet
*pktin
)
7667 struct do_ssh2_authconn_state
{
7671 AUTH_TYPE_PUBLICKEY
,
7672 AUTH_TYPE_PUBLICKEY_OFFER_LOUD
,
7673 AUTH_TYPE_PUBLICKEY_OFFER_QUIET
,
7675 AUTH_TYPE_GSSAPI
, /* always QUIET */
7676 AUTH_TYPE_KEYBOARD_INTERACTIVE
,
7677 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
7679 int done_service_req
;
7680 int gotit
, need_pw
, can_pubkey
, can_passwd
, can_keyb_inter
;
7681 int tried_pubkey_config
, done_agent
;
7686 int kbd_inter_refused
;
7687 int we_are_in
, userauth_success
;
7688 prompts_t
*cur_prompt
;
7693 void *publickey_blob
;
7694 int publickey_bloblen
;
7695 int publickey_encrypted
;
7696 char *publickey_algorithm
;
7697 char *publickey_comment
;
7698 unsigned char agent_request
[5], *agent_response
, *agentp
;
7699 int agent_responselen
;
7700 unsigned char *pkblob_in_agent
;
7702 char *pkblob
, *alg
, *commentp
;
7703 int pklen
, alglen
, commentlen
;
7704 int siglen
, retlen
, len
;
7705 char *q
, *agentreq
, *ret
;
7707 struct Packet
*pktout
;
7710 struct ssh_gss_library
*gsslib
;
7711 Ssh_gss_ctx gss_ctx
;
7712 Ssh_gss_buf gss_buf
;
7713 Ssh_gss_buf gss_rcvtok
, gss_sndtok
;
7714 Ssh_gss_name gss_srv_name
;
7715 Ssh_gss_stat gss_stat
;
7718 crState(do_ssh2_authconn_state
);
7722 /* Register as a handler for all the messages this coroutine handles. */
7723 ssh
->packet_dispatch
[SSH2_MSG_SERVICE_ACCEPT
] = ssh2_msg_authconn
;
7724 ssh
->packet_dispatch
[SSH2_MSG_USERAUTH_REQUEST
] = ssh2_msg_authconn
;
7725 ssh
->packet_dispatch
[SSH2_MSG_USERAUTH_FAILURE
] = ssh2_msg_authconn
;
7726 ssh
->packet_dispatch
[SSH2_MSG_USERAUTH_SUCCESS
] = ssh2_msg_authconn
;
7727 ssh
->packet_dispatch
[SSH2_MSG_USERAUTH_BANNER
] = ssh2_msg_authconn
;
7728 ssh
->packet_dispatch
[SSH2_MSG_USERAUTH_PK_OK
] = ssh2_msg_authconn
;
7729 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = ssh2_msg_authconn; duplicate case value */
7730 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = ssh2_msg_authconn; duplicate case value */
7731 ssh
->packet_dispatch
[SSH2_MSG_USERAUTH_INFO_RESPONSE
] = ssh2_msg_authconn
;
7732 ssh
->packet_dispatch
[SSH2_MSG_GLOBAL_REQUEST
] = ssh2_msg_authconn
;
7733 ssh
->packet_dispatch
[SSH2_MSG_REQUEST_SUCCESS
] = ssh2_msg_authconn
;
7734 ssh
->packet_dispatch
[SSH2_MSG_REQUEST_FAILURE
] = ssh2_msg_authconn
;
7735 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_OPEN
] = ssh2_msg_authconn
;
7736 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
] = ssh2_msg_authconn
;
7737 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_OPEN_FAILURE
] = ssh2_msg_authconn
;
7738 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_WINDOW_ADJUST
] = ssh2_msg_authconn
;
7739 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_DATA
] = ssh2_msg_authconn
;
7740 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_EXTENDED_DATA
] = ssh2_msg_authconn
;
7741 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_EOF
] = ssh2_msg_authconn
;
7742 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_CLOSE
] = ssh2_msg_authconn
;
7744 s
->done_service_req
= FALSE
;
7745 s
->we_are_in
= s
->userauth_success
= FALSE
;
7747 s
->tried_gssapi
= FALSE
;
7750 if (!conf_get_int(ssh
->conf
, CONF_ssh_no_userauth
)) {
7752 * Request userauth protocol, and await a response to it.
7754 s
->pktout
= ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST
);
7755 ssh2_pkt_addstring(s
->pktout
, "ssh-userauth");
7756 ssh2_pkt_send(ssh
, s
->pktout
);
7757 crWaitUntilV(pktin
);
7758 if (pktin
->type
== SSH2_MSG_SERVICE_ACCEPT
)
7759 s
->done_service_req
= TRUE
;
7761 if (!s
->done_service_req
) {
7763 * Request connection protocol directly, without authentication.
7765 s
->pktout
= ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST
);
7766 ssh2_pkt_addstring(s
->pktout
, "ssh-connection");
7767 ssh2_pkt_send(ssh
, s
->pktout
);
7768 crWaitUntilV(pktin
);
7769 if (pktin
->type
== SSH2_MSG_SERVICE_ACCEPT
) {
7770 s
->we_are_in
= TRUE
; /* no auth required */
7772 bombout(("Server refused service request"));
7777 /* Arrange to be able to deal with any BANNERs that come in.
7778 * (We do this now as packets may come in during the next bit.) */
7779 bufchain_init(&ssh
->banner
);
7780 ssh
->packet_dispatch
[SSH2_MSG_USERAUTH_BANNER
] =
7781 ssh2_msg_userauth_banner
;
7784 * Misc one-time setup for authentication.
7786 s
->publickey_blob
= NULL
;
7787 if (!s
->we_are_in
) {
7790 * Load the public half of any configured public key file
7793 s
->keyfile
= conf_get_filename(ssh
->conf
, CONF_keyfile
);
7794 if (!filename_is_null(s
->keyfile
)) {
7796 logeventf(ssh
, "Reading private key file \"%.150s\"",
7797 filename_to_str(s
->keyfile
));
7798 keytype
= key_type(s
->keyfile
);
7799 if (keytype
== SSH_KEYTYPE_SSH2
) {
7802 ssh2_userkey_loadpub(s
->keyfile
,
7803 &s
->publickey_algorithm
,
7804 &s
->publickey_bloblen
,
7805 &s
->publickey_comment
, &error
);
7806 if (s
->publickey_blob
) {
7807 s
->publickey_encrypted
=
7808 ssh2_userkey_encrypted(s
->keyfile
, NULL
);
7811 logeventf(ssh
, "Unable to load private key (%s)",
7813 msgbuf
= dupprintf("Unable to load private key file "
7814 "\"%.150s\" (%s)\r\n",
7815 filename_to_str(s
->keyfile
),
7817 c_write_str(ssh
, msgbuf
);
7822 logeventf(ssh
, "Unable to use this key file (%s)",
7823 key_type_to_str(keytype
));
7824 msgbuf
= dupprintf("Unable to use key file \"%.150s\""
7826 filename_to_str(s
->keyfile
),
7827 key_type_to_str(keytype
));
7828 c_write_str(ssh
, msgbuf
);
7830 s
->publickey_blob
= NULL
;
7835 * Find out about any keys Pageant has (but if there's a
7836 * public key configured, filter out all others).
7839 s
->agent_response
= NULL
;
7840 s
->pkblob_in_agent
= NULL
;
7841 if (conf_get_int(ssh
->conf
, CONF_tryagent
) && agent_exists()) {
7845 logevent("Pageant is running. Requesting keys.");
7847 /* Request the keys held by the agent. */
7848 PUT_32BIT(s
->agent_request
, 1);
7849 s
->agent_request
[4] = SSH2_AGENTC_REQUEST_IDENTITIES
;
7850 if (!agent_query(s
->agent_request
, 5, &r
, &s
->agent_responselen
,
7851 ssh_agent_callback
, ssh
)) {
7855 bombout(("Unexpected data from server while"
7856 " waiting for agent response"));
7859 } while (pktin
|| inlen
> 0);
7860 r
= ssh
->agent_response
;
7861 s
->agent_responselen
= ssh
->agent_response_len
;
7863 s
->agent_response
= (unsigned char *) r
;
7864 if (s
->agent_response
&& s
->agent_responselen
>= 5 &&
7865 s
->agent_response
[4] == SSH2_AGENT_IDENTITIES_ANSWER
) {
7868 p
= s
->agent_response
+ 5;
7869 s
->nkeys
= GET_32BIT(p
);
7871 logeventf(ssh
, "Pageant has %d SSH-2 keys", s
->nkeys
);
7872 if (s
->publickey_blob
) {
7873 /* See if configured key is in agent. */
7874 for (keyi
= 0; keyi
< s
->nkeys
; keyi
++) {
7875 s
->pklen
= GET_32BIT(p
);
7876 if (s
->pklen
== s
->publickey_bloblen
&&
7877 !memcmp(p
+4, s
->publickey_blob
,
7878 s
->publickey_bloblen
)) {
7879 logeventf(ssh
, "Pageant key #%d matches "
7880 "configured key file", keyi
);
7882 s
->pkblob_in_agent
= p
;
7886 p
+= GET_32BIT(p
) + 4; /* comment */
7888 if (!s
->pkblob_in_agent
) {
7889 logevent("Configured key file not in Pageant");
7894 logevent("Failed to get reply from Pageant");
7901 * We repeat this whole loop, including the username prompt,
7902 * until we manage a successful authentication. If the user
7903 * types the wrong _password_, they can be sent back to the
7904 * beginning to try another username, if this is configured on.
7905 * (If they specify a username in the config, they are never
7906 * asked, even if they do give a wrong password.)
7908 * I think this best serves the needs of
7910 * - the people who have no configuration, no keys, and just
7911 * want to try repeated (username,password) pairs until they
7912 * type both correctly
7914 * - people who have keys and configuration but occasionally
7915 * need to fall back to passwords
7917 * - people with a key held in Pageant, who might not have
7918 * logged in to a particular machine before; so they want to
7919 * type a username, and then _either_ their key will be
7920 * accepted, _or_ they will type a password. If they mistype
7921 * the username they will want to be able to get back and
7924 s
->got_username
= FALSE
;
7925 while (!s
->we_are_in
) {
7929 if (s
->got_username
&& !conf_get_int(ssh
->conf
, CONF_change_username
)) {
7931 * We got a username last time round this loop, and
7932 * with change_username turned off we don't try to get
7935 } else if ((ssh
->username
= get_remote_username(ssh
->conf
)) == NULL
) {
7936 int ret
; /* need not be kept over crReturn */
7937 s
->cur_prompt
= new_prompts(ssh
->frontend
);
7938 s
->cur_prompt
->to_server
= TRUE
;
7939 s
->cur_prompt
->name
= dupstr("SSH login name");
7940 add_prompt(s
->cur_prompt
, dupstr("login as: "), TRUE
);
7941 ret
= get_userpass_input(s
->cur_prompt
, NULL
, 0);
7944 crWaitUntilV(!pktin
);
7945 ret
= get_userpass_input(s
->cur_prompt
, in
, inlen
);
7950 * get_userpass_input() failed to get a username.
7953 free_prompts(s
->cur_prompt
);
7954 ssh_disconnect(ssh
, "No username provided", NULL
, 0, TRUE
);
7957 ssh
->username
= dupstr(s
->cur_prompt
->prompts
[0]->result
);
7958 free_prompts(s
->cur_prompt
);
7961 if ((flags
& FLAG_VERBOSE
) || (flags
& FLAG_INTERACTIVE
)) {
7962 stuff
= dupprintf("Using username \"%s\".\r\n", ssh
->username
);
7963 c_write_str(ssh
, stuff
);
7967 s
->got_username
= TRUE
;
7970 * Send an authentication request using method "none": (a)
7971 * just in case it succeeds, and (b) so that we know what
7972 * authentication methods we can usefully try next.
7974 ssh
->pkt_actx
= SSH2_PKTCTX_NOAUTH
;
7976 s
->pktout
= ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
7977 ssh2_pkt_addstring(s
->pktout
, ssh
->username
);
7978 ssh2_pkt_addstring(s
->pktout
, "ssh-connection");/* service requested */
7979 ssh2_pkt_addstring(s
->pktout
, "none"); /* method */
7980 ssh2_pkt_send(ssh
, s
->pktout
);
7981 s
->type
= AUTH_TYPE_NONE
;
7983 s
->we_are_in
= FALSE
;
7985 s
->tried_pubkey_config
= FALSE
;
7986 s
->kbd_inter_refused
= FALSE
;
7988 /* Reset agent request state. */
7989 s
->done_agent
= FALSE
;
7990 if (s
->agent_response
) {
7991 if (s
->pkblob_in_agent
) {
7992 s
->agentp
= s
->pkblob_in_agent
;
7994 s
->agentp
= s
->agent_response
+ 5 + 4;
8000 char *methods
= NULL
;
8004 * Wait for the result of the last authentication request.
8007 crWaitUntilV(pktin
);
8009 * Now is a convenient point to spew any banner material
8010 * that we've accumulated. (This should ensure that when
8011 * we exit the auth loop, we haven't any left to deal
8015 int size
= bufchain_size(&ssh
->banner
);
8017 * Don't show the banner if we're operating in
8018 * non-verbose non-interactive mode. (It's probably
8019 * a script, which means nobody will read the
8020 * banner _anyway_, and moreover the printing of
8021 * the banner will screw up processing on the
8022 * output of (say) plink.)
8024 if (size
&& (flags
& (FLAG_VERBOSE
| FLAG_INTERACTIVE
))) {
8025 char *banner
= snewn(size
, char);
8026 bufchain_fetch(&ssh
->banner
, banner
, size
);
8027 c_write_untrusted(ssh
, banner
, size
);
8030 bufchain_clear(&ssh
->banner
);
8032 if (pktin
->type
== SSH2_MSG_USERAUTH_SUCCESS
) {
8033 logevent("Access granted");
8034 s
->we_are_in
= s
->userauth_success
= TRUE
;
8038 if (pktin
->type
!= SSH2_MSG_USERAUTH_FAILURE
&& s
->type
!= AUTH_TYPE_GSSAPI
) {
8039 bombout(("Strange packet received during authentication: "
8040 "type %d", pktin
->type
));
8047 * OK, we're now sitting on a USERAUTH_FAILURE message, so
8048 * we can look at the string in it and know what we can
8049 * helpfully try next.
8051 if (pktin
->type
== SSH2_MSG_USERAUTH_FAILURE
) {
8052 ssh_pkt_getstring(pktin
, &methods
, &methlen
);
8053 if (!ssh2_pkt_getbool(pktin
)) {
8055 * We have received an unequivocal Access
8056 * Denied. This can translate to a variety of
8057 * messages, or no message at all.
8059 * For forms of authentication which are attempted
8060 * implicitly, by which I mean without printing
8061 * anything in the window indicating that we're
8062 * trying them, we should never print 'Access
8065 * If we do print a message saying that we're
8066 * attempting some kind of authentication, it's OK
8067 * to print a followup message saying it failed -
8068 * but the message may sometimes be more specific
8069 * than simply 'Access denied'.
8071 * Additionally, if we'd just tried password
8072 * authentication, we should break out of this
8073 * whole loop so as to go back to the username
8074 * prompt (iff we're configured to allow
8075 * username change attempts).
8077 if (s
->type
== AUTH_TYPE_NONE
) {
8079 } else if (s
->type
== AUTH_TYPE_PUBLICKEY_OFFER_LOUD
||
8080 s
->type
== AUTH_TYPE_PUBLICKEY_OFFER_QUIET
) {
8081 if (s
->type
== AUTH_TYPE_PUBLICKEY_OFFER_LOUD
)
8082 c_write_str(ssh
, "Server refused our key\r\n");
8083 logevent("Server refused our key");
8084 } else if (s
->type
== AUTH_TYPE_PUBLICKEY
) {
8085 /* This _shouldn't_ happen except by a
8086 * protocol bug causing client and server to
8087 * disagree on what is a correct signature. */
8088 c_write_str(ssh
, "Server refused public-key signature"
8089 " despite accepting key!\r\n");
8090 logevent("Server refused public-key signature"
8091 " despite accepting key!");
8092 } else if (s
->type
==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
) {
8093 /* quiet, so no c_write */
8094 logevent("Server refused keyboard-interactive authentication");
8095 } else if (s
->type
==AUTH_TYPE_GSSAPI
) {
8096 /* always quiet, so no c_write */
8097 /* also, the code down in the GSSAPI block has
8098 * already logged this in the Event Log */
8099 } else if (s
->type
== AUTH_TYPE_KEYBOARD_INTERACTIVE
) {
8100 logevent("Keyboard-interactive authentication failed");
8101 c_write_str(ssh
, "Access denied\r\n");
8103 assert(s
->type
== AUTH_TYPE_PASSWORD
);
8104 logevent("Password authentication failed");
8105 c_write_str(ssh
, "Access denied\r\n");
8107 if (conf_get_int(ssh
->conf
, CONF_change_username
)) {
8108 /* XXX perhaps we should allow
8109 * keyboard-interactive to do this too? */
8110 s
->we_are_in
= FALSE
;
8115 c_write_str(ssh
, "Further authentication required\r\n");
8116 logevent("Further authentication required");
8120 in_commasep_string("publickey", methods
, methlen
);
8122 in_commasep_string("password", methods
, methlen
);
8123 s
->can_keyb_inter
= conf_get_int(ssh
->conf
, CONF_try_ki_auth
) &&
8124 in_commasep_string("keyboard-interactive", methods
, methlen
);
8127 ssh
->gsslibs
= ssh_gss_setup(ssh
->conf
);
8128 s
->can_gssapi
= conf_get_int(ssh
->conf
, CONF_try_gssapi_auth
) &&
8129 in_commasep_string("gssapi-with-mic", methods
, methlen
) &&
8130 ssh
->gsslibs
->nlibraries
> 0;
8134 ssh
->pkt_actx
= SSH2_PKTCTX_NOAUTH
;
8136 if (s
->can_pubkey
&& !s
->done_agent
&& s
->nkeys
) {
8139 * Attempt public-key authentication using a key from Pageant.
8142 ssh
->pkt_actx
= SSH2_PKTCTX_PUBLICKEY
;
8144 logeventf(ssh
, "Trying Pageant key #%d", s
->keyi
);
8146 /* Unpack key from agent response */
8147 s
->pklen
= GET_32BIT(s
->agentp
);
8149 s
->pkblob
= (char *)s
->agentp
;
8150 s
->agentp
+= s
->pklen
;
8151 s
->alglen
= GET_32BIT(s
->pkblob
);
8152 s
->alg
= s
->pkblob
+ 4;
8153 s
->commentlen
= GET_32BIT(s
->agentp
);
8155 s
->commentp
= (char *)s
->agentp
;
8156 s
->agentp
+= s
->commentlen
;
8157 /* s->agentp now points at next key, if any */
8159 /* See if server will accept it */
8160 s
->pktout
= ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
8161 ssh2_pkt_addstring(s
->pktout
, ssh
->username
);
8162 ssh2_pkt_addstring(s
->pktout
, "ssh-connection");
8163 /* service requested */
8164 ssh2_pkt_addstring(s
->pktout
, "publickey");
8166 ssh2_pkt_addbool(s
->pktout
, FALSE
); /* no signature included */
8167 ssh2_pkt_addstring_start(s
->pktout
);
8168 ssh2_pkt_addstring_data(s
->pktout
, s
->alg
, s
->alglen
);
8169 ssh2_pkt_addstring_start(s
->pktout
);
8170 ssh2_pkt_addstring_data(s
->pktout
, s
->pkblob
, s
->pklen
);
8171 ssh2_pkt_send(ssh
, s
->pktout
);
8172 s
->type
= AUTH_TYPE_PUBLICKEY_OFFER_QUIET
;
8174 crWaitUntilV(pktin
);
8175 if (pktin
->type
!= SSH2_MSG_USERAUTH_PK_OK
) {
8177 /* Offer of key refused. */
8184 if (flags
& FLAG_VERBOSE
) {
8185 c_write_str(ssh
, "Authenticating with "
8187 c_write(ssh
, s
->commentp
, s
->commentlen
);
8188 c_write_str(ssh
, "\" from agent\r\n");
8192 * Server is willing to accept the key.
8193 * Construct a SIGN_REQUEST.
8195 s
->pktout
= ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
8196 ssh2_pkt_addstring(s
->pktout
, ssh
->username
);
8197 ssh2_pkt_addstring(s
->pktout
, "ssh-connection");
8198 /* service requested */
8199 ssh2_pkt_addstring(s
->pktout
, "publickey");
8201 ssh2_pkt_addbool(s
->pktout
, TRUE
); /* signature included */
8202 ssh2_pkt_addstring_start(s
->pktout
);
8203 ssh2_pkt_addstring_data(s
->pktout
, s
->alg
, s
->alglen
);
8204 ssh2_pkt_addstring_start(s
->pktout
);
8205 ssh2_pkt_addstring_data(s
->pktout
, s
->pkblob
, s
->pklen
);
8207 /* Ask agent for signature. */
8208 s
->siglen
= s
->pktout
->length
- 5 + 4 +
8209 ssh
->v2_session_id_len
;
8210 if (ssh
->remote_bugs
& BUG_SSH2_PK_SESSIONID
)
8212 s
->len
= 1; /* message type */
8213 s
->len
+= 4 + s
->pklen
; /* key blob */
8214 s
->len
+= 4 + s
->siglen
; /* data to sign */
8215 s
->len
+= 4; /* flags */
8216 s
->agentreq
= snewn(4 + s
->len
, char);
8217 PUT_32BIT(s
->agentreq
, s
->len
);
8218 s
->q
= s
->agentreq
+ 4;
8219 *s
->q
++ = SSH2_AGENTC_SIGN_REQUEST
;
8220 PUT_32BIT(s
->q
, s
->pklen
);
8222 memcpy(s
->q
, s
->pkblob
, s
->pklen
);
8224 PUT_32BIT(s
->q
, s
->siglen
);
8226 /* Now the data to be signed... */
8227 if (!(ssh
->remote_bugs
& BUG_SSH2_PK_SESSIONID
)) {
8228 PUT_32BIT(s
->q
, ssh
->v2_session_id_len
);
8231 memcpy(s
->q
, ssh
->v2_session_id
,
8232 ssh
->v2_session_id_len
);
8233 s
->q
+= ssh
->v2_session_id_len
;
8234 memcpy(s
->q
, s
->pktout
->data
+ 5,
8235 s
->pktout
->length
- 5);
8236 s
->q
+= s
->pktout
->length
- 5;
8237 /* And finally the (zero) flags word. */
8239 if (!agent_query(s
->agentreq
, s
->len
+ 4,
8241 ssh_agent_callback
, ssh
)) {
8245 bombout(("Unexpected data from server"
8246 " while waiting for agent"
8250 } while (pktin
|| inlen
> 0);
8251 vret
= ssh
->agent_response
;
8252 s
->retlen
= ssh
->agent_response_len
;
8257 if (s
->ret
[4] == SSH2_AGENT_SIGN_RESPONSE
) {
8258 logevent("Sending Pageant's response");
8259 ssh2_add_sigblob(ssh
, s
->pktout
,
8260 s
->pkblob
, s
->pklen
,
8262 GET_32BIT(s
->ret
+ 5));
8263 ssh2_pkt_send(ssh
, s
->pktout
);
8264 s
->type
= AUTH_TYPE_PUBLICKEY
;
8266 /* FIXME: less drastic response */
8267 bombout(("Pageant failed to answer challenge"));
8273 /* Do we have any keys left to try? */
8274 if (s
->pkblob_in_agent
) {
8275 s
->done_agent
= TRUE
;
8276 s
->tried_pubkey_config
= TRUE
;
8279 if (s
->keyi
>= s
->nkeys
)
8280 s
->done_agent
= TRUE
;
8283 } else if (s
->can_pubkey
&& s
->publickey_blob
&&
8284 !s
->tried_pubkey_config
) {
8286 struct ssh2_userkey
*key
; /* not live over crReturn */
8287 char *passphrase
; /* not live over crReturn */
8289 ssh
->pkt_actx
= SSH2_PKTCTX_PUBLICKEY
;
8291 s
->tried_pubkey_config
= TRUE
;
8294 * Try the public key supplied in the configuration.
8296 * First, offer the public blob to see if the server is
8297 * willing to accept it.
8299 s
->pktout
= ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
8300 ssh2_pkt_addstring(s
->pktout
, ssh
->username
);
8301 ssh2_pkt_addstring(s
->pktout
, "ssh-connection");
8302 /* service requested */
8303 ssh2_pkt_addstring(s
->pktout
, "publickey"); /* method */
8304 ssh2_pkt_addbool(s
->pktout
, FALSE
);
8305 /* no signature included */
8306 ssh2_pkt_addstring(s
->pktout
, s
->publickey_algorithm
);
8307 ssh2_pkt_addstring_start(s
->pktout
);
8308 ssh2_pkt_addstring_data(s
->pktout
,
8309 (char *)s
->publickey_blob
,
8310 s
->publickey_bloblen
);
8311 ssh2_pkt_send(ssh
, s
->pktout
);
8312 logevent("Offered public key");
8314 crWaitUntilV(pktin
);
8315 if (pktin
->type
!= SSH2_MSG_USERAUTH_PK_OK
) {
8316 /* Key refused. Give up. */
8317 s
->gotit
= TRUE
; /* reconsider message next loop */
8318 s
->type
= AUTH_TYPE_PUBLICKEY_OFFER_LOUD
;
8319 continue; /* process this new message */
8321 logevent("Offer of public key accepted");
8324 * Actually attempt a serious authentication using
8327 if (flags
& FLAG_VERBOSE
) {
8328 c_write_str(ssh
, "Authenticating with public key \"");
8329 c_write_str(ssh
, s
->publickey_comment
);
8330 c_write_str(ssh
, "\"\r\n");
8334 const char *error
; /* not live over crReturn */
8335 if (s
->publickey_encrypted
) {
8337 * Get a passphrase from the user.
8339 int ret
; /* need not be kept over crReturn */
8340 s
->cur_prompt
= new_prompts(ssh
->frontend
);
8341 s
->cur_prompt
->to_server
= FALSE
;
8342 s
->cur_prompt
->name
= dupstr("SSH key passphrase");
8343 add_prompt(s
->cur_prompt
,
8344 dupprintf("Passphrase for key \"%.100s\": ",
8345 s
->publickey_comment
),
8347 ret
= get_userpass_input(s
->cur_prompt
, NULL
, 0);
8350 crWaitUntilV(!pktin
);
8351 ret
= get_userpass_input(s
->cur_prompt
,
8356 /* Failed to get a passphrase. Terminate. */
8357 free_prompts(s
->cur_prompt
);
8358 ssh_disconnect(ssh
, NULL
,
8359 "Unable to authenticate",
8360 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER
,
8365 dupstr(s
->cur_prompt
->prompts
[0]->result
);
8366 free_prompts(s
->cur_prompt
);
8368 passphrase
= NULL
; /* no passphrase needed */
8372 * Try decrypting the key.
8374 s
->keyfile
= conf_get_filename(ssh
->conf
, CONF_keyfile
);
8375 key
= ssh2_load_userkey(s
->keyfile
, passphrase
, &error
);
8377 /* burn the evidence */
8378 smemclr(passphrase
, strlen(passphrase
));
8381 if (key
== SSH2_WRONG_PASSPHRASE
|| key
== NULL
) {
8383 (key
== SSH2_WRONG_PASSPHRASE
)) {
8384 c_write_str(ssh
, "Wrong passphrase\r\n");
8386 /* and loop again */
8388 c_write_str(ssh
, "Unable to load private key (");
8389 c_write_str(ssh
, error
);
8390 c_write_str(ssh
, ")\r\n");
8392 break; /* try something else */
8398 unsigned char *pkblob
, *sigblob
, *sigdata
;
8399 int pkblob_len
, sigblob_len
, sigdata_len
;
8403 * We have loaded the private key and the server
8404 * has announced that it's willing to accept it.
8405 * Hallelujah. Generate a signature and send it.
8407 s
->pktout
= ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
8408 ssh2_pkt_addstring(s
->pktout
, ssh
->username
);
8409 ssh2_pkt_addstring(s
->pktout
, "ssh-connection");
8410 /* service requested */
8411 ssh2_pkt_addstring(s
->pktout
, "publickey");
8413 ssh2_pkt_addbool(s
->pktout
, TRUE
);
8414 /* signature follows */
8415 ssh2_pkt_addstring(s
->pktout
, key
->alg
->name
);
8416 pkblob
= key
->alg
->public_blob(key
->data
,
8418 ssh2_pkt_addstring_start(s
->pktout
);
8419 ssh2_pkt_addstring_data(s
->pktout
, (char *)pkblob
,
8423 * The data to be signed is:
8427 * followed by everything so far placed in the
8430 sigdata_len
= s
->pktout
->length
- 5 + 4 +
8431 ssh
->v2_session_id_len
;
8432 if (ssh
->remote_bugs
& BUG_SSH2_PK_SESSIONID
)
8434 sigdata
= snewn(sigdata_len
, unsigned char);
8436 if (!(ssh
->remote_bugs
& BUG_SSH2_PK_SESSIONID
)) {
8437 PUT_32BIT(sigdata
+p
, ssh
->v2_session_id_len
);
8440 memcpy(sigdata
+p
, ssh
->v2_session_id
,
8441 ssh
->v2_session_id_len
);
8442 p
+= ssh
->v2_session_id_len
;
8443 memcpy(sigdata
+p
, s
->pktout
->data
+ 5,
8444 s
->pktout
->length
- 5);
8445 p
+= s
->pktout
->length
- 5;
8446 assert(p
== sigdata_len
);
8447 sigblob
= key
->alg
->sign(key
->data
, (char *)sigdata
,
8448 sigdata_len
, &sigblob_len
);
8449 ssh2_add_sigblob(ssh
, s
->pktout
, pkblob
, pkblob_len
,
8450 sigblob
, sigblob_len
);
8455 ssh2_pkt_send(ssh
, s
->pktout
);
8456 logevent("Sent public key signature");
8457 s
->type
= AUTH_TYPE_PUBLICKEY
;
8458 key
->alg
->freekey(key
->data
);
8462 } else if (s
->can_gssapi
&& !s
->tried_gssapi
) {
8464 /* GSSAPI Authentication */
8469 s
->type
= AUTH_TYPE_GSSAPI
;
8470 s
->tried_gssapi
= TRUE
;
8472 ssh
->pkt_actx
= SSH2_PKTCTX_GSSAPI
;
8475 * Pick the highest GSS library on the preference
8481 for (i
= 0; i
< ngsslibs
; i
++) {
8482 int want_id
= conf_get_int_int(ssh
->conf
,
8483 CONF_ssh_gsslist
, i
);
8484 for (j
= 0; j
< ssh
->gsslibs
->nlibraries
; j
++)
8485 if (ssh
->gsslibs
->libraries
[j
].id
== want_id
) {
8486 s
->gsslib
= &ssh
->gsslibs
->libraries
[j
];
8487 goto got_gsslib
; /* double break */
8492 * We always expect to have found something in
8493 * the above loop: we only came here if there
8494 * was at least one viable GSS library, and the
8495 * preference list should always mention
8496 * everything and only change the order.
8501 if (s
->gsslib
->gsslogmsg
)
8502 logevent(s
->gsslib
->gsslogmsg
);
8504 /* Sending USERAUTH_REQUEST with "gssapi-with-mic" method */
8505 s
->pktout
= ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
8506 ssh2_pkt_addstring(s
->pktout
, ssh
->username
);
8507 ssh2_pkt_addstring(s
->pktout
, "ssh-connection");
8508 ssh2_pkt_addstring(s
->pktout
, "gssapi-with-mic");
8509 logevent("Attempting GSSAPI authentication");
8511 /* add mechanism info */
8512 s
->gsslib
->indicate_mech(s
->gsslib
, &s
->gss_buf
);
8514 /* number of GSSAPI mechanisms */
8515 ssh2_pkt_adduint32(s
->pktout
,1);
8517 /* length of OID + 2 */
8518 ssh2_pkt_adduint32(s
->pktout
, s
->gss_buf
.length
+ 2);
8519 ssh2_pkt_addbyte(s
->pktout
, SSH2_GSS_OIDTYPE
);
8522 ssh2_pkt_addbyte(s
->pktout
, (unsigned char) s
->gss_buf
.length
);
8524 ssh_pkt_adddata(s
->pktout
, s
->gss_buf
.value
,
8526 ssh2_pkt_send(ssh
, s
->pktout
);
8527 crWaitUntilV(pktin
);
8528 if (pktin
->type
!= SSH2_MSG_USERAUTH_GSSAPI_RESPONSE
) {
8529 logevent("GSSAPI authentication request refused");
8533 /* check returned packet ... */
8535 ssh_pkt_getstring(pktin
, &data
, &len
);
8536 s
->gss_rcvtok
.value
= data
;
8537 s
->gss_rcvtok
.length
= len
;
8538 if (s
->gss_rcvtok
.length
!= s
->gss_buf
.length
+ 2 ||
8539 ((char *)s
->gss_rcvtok
.value
)[0] != SSH2_GSS_OIDTYPE
||
8540 ((char *)s
->gss_rcvtok
.value
)[1] != s
->gss_buf
.length
||
8541 memcmp((char *)s
->gss_rcvtok
.value
+ 2,
8542 s
->gss_buf
.value
,s
->gss_buf
.length
) ) {
8543 logevent("GSSAPI authentication - wrong response from server");
8547 /* now start running */
8548 s
->gss_stat
= s
->gsslib
->import_name(s
->gsslib
,
8551 if (s
->gss_stat
!= SSH_GSS_OK
) {
8552 if (s
->gss_stat
== SSH_GSS_BAD_HOST_NAME
)
8553 logevent("GSSAPI import name failed - Bad service name");
8555 logevent("GSSAPI import name failed");
8559 /* fetch TGT into GSS engine */
8560 s
->gss_stat
= s
->gsslib
->acquire_cred(s
->gsslib
, &s
->gss_ctx
);
8562 if (s
->gss_stat
!= SSH_GSS_OK
) {
8563 logevent("GSSAPI authentication failed to get credentials");
8564 s
->gsslib
->release_name(s
->gsslib
, &s
->gss_srv_name
);
8568 /* initial tokens are empty */
8569 SSH_GSS_CLEAR_BUF(&s
->gss_rcvtok
);
8570 SSH_GSS_CLEAR_BUF(&s
->gss_sndtok
);
8572 /* now enter the loop */
8574 s
->gss_stat
= s
->gsslib
->init_sec_context
8578 conf_get_int(ssh
->conf
, CONF_gssapifwd
),
8582 if (s
->gss_stat
!=SSH_GSS_S_COMPLETE
&&
8583 s
->gss_stat
!=SSH_GSS_S_CONTINUE_NEEDED
) {
8584 logevent("GSSAPI authentication initialisation failed");
8586 if (s
->gsslib
->display_status(s
->gsslib
, s
->gss_ctx
,
8587 &s
->gss_buf
) == SSH_GSS_OK
) {
8588 logevent(s
->gss_buf
.value
);
8589 sfree(s
->gss_buf
.value
);
8594 logevent("GSSAPI authentication initialised");
8596 /* Client and server now exchange tokens until GSSAPI
8597 * no longer says CONTINUE_NEEDED */
8599 if (s
->gss_sndtok
.length
!= 0) {
8600 s
->pktout
= ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_TOKEN
);
8601 ssh_pkt_addstring_start(s
->pktout
);
8602 ssh_pkt_addstring_data(s
->pktout
,s
->gss_sndtok
.value
,s
->gss_sndtok
.length
);
8603 ssh2_pkt_send(ssh
, s
->pktout
);
8604 s
->gsslib
->free_tok(s
->gsslib
, &s
->gss_sndtok
);
8607 if (s
->gss_stat
== SSH_GSS_S_CONTINUE_NEEDED
) {
8608 crWaitUntilV(pktin
);
8609 if (pktin
->type
!= SSH2_MSG_USERAUTH_GSSAPI_TOKEN
) {
8610 logevent("GSSAPI authentication - bad server response");
8611 s
->gss_stat
= SSH_GSS_FAILURE
;
8614 ssh_pkt_getstring(pktin
, &data
, &len
);
8615 s
->gss_rcvtok
.value
= data
;
8616 s
->gss_rcvtok
.length
= len
;
8618 } while (s
-> gss_stat
== SSH_GSS_S_CONTINUE_NEEDED
);
8620 if (s
->gss_stat
!= SSH_GSS_OK
) {
8621 s
->gsslib
->release_name(s
->gsslib
, &s
->gss_srv_name
);
8622 s
->gsslib
->release_cred(s
->gsslib
, &s
->gss_ctx
);
8625 logevent("GSSAPI authentication loop finished OK");
8627 /* Now send the MIC */
8629 s
->pktout
= ssh2_pkt_init(0);
8630 micoffset
= s
->pktout
->length
;
8631 ssh_pkt_addstring_start(s
->pktout
);
8632 ssh_pkt_addstring_data(s
->pktout
, (char *)ssh
->v2_session_id
, ssh
->v2_session_id_len
);
8633 ssh_pkt_addbyte(s
->pktout
, SSH2_MSG_USERAUTH_REQUEST
);
8634 ssh_pkt_addstring(s
->pktout
, ssh
->username
);
8635 ssh_pkt_addstring(s
->pktout
, "ssh-connection");
8636 ssh_pkt_addstring(s
->pktout
, "gssapi-with-mic");
8638 s
->gss_buf
.value
= (char *)s
->pktout
->data
+ micoffset
;
8639 s
->gss_buf
.length
= s
->pktout
->length
- micoffset
;
8641 s
->gsslib
->get_mic(s
->gsslib
, s
->gss_ctx
, &s
->gss_buf
, &mic
);
8642 s
->pktout
= ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_MIC
);
8643 ssh_pkt_addstring_start(s
->pktout
);
8644 ssh_pkt_addstring_data(s
->pktout
, mic
.value
, mic
.length
);
8645 ssh2_pkt_send(ssh
, s
->pktout
);
8646 s
->gsslib
->free_mic(s
->gsslib
, &mic
);
8650 s
->gsslib
->release_name(s
->gsslib
, &s
->gss_srv_name
);
8651 s
->gsslib
->release_cred(s
->gsslib
, &s
->gss_ctx
);
8654 } else if (s
->can_keyb_inter
&& !s
->kbd_inter_refused
) {
8657 * Keyboard-interactive authentication.
8660 s
->type
= AUTH_TYPE_KEYBOARD_INTERACTIVE
;
8662 ssh
->pkt_actx
= SSH2_PKTCTX_KBDINTER
;
8664 s
->pktout
= ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
8665 ssh2_pkt_addstring(s
->pktout
, ssh
->username
);
8666 ssh2_pkt_addstring(s
->pktout
, "ssh-connection");
8667 /* service requested */
8668 ssh2_pkt_addstring(s
->pktout
, "keyboard-interactive");
8670 ssh2_pkt_addstring(s
->pktout
, ""); /* lang */
8671 ssh2_pkt_addstring(s
->pktout
, ""); /* submethods */
8672 ssh2_pkt_send(ssh
, s
->pktout
);
8674 logevent("Attempting keyboard-interactive authentication");
8676 crWaitUntilV(pktin
);
8677 if (pktin
->type
!= SSH2_MSG_USERAUTH_INFO_REQUEST
) {
8678 /* Server is not willing to do keyboard-interactive
8679 * at all (or, bizarrely but legally, accepts the
8680 * user without actually issuing any prompts).
8681 * Give up on it entirely. */
8683 s
->type
= AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
;
8684 s
->kbd_inter_refused
= TRUE
; /* don't try it again */
8689 * Loop while the server continues to send INFO_REQUESTs.
8691 while (pktin
->type
== SSH2_MSG_USERAUTH_INFO_REQUEST
) {
8693 char *name
, *inst
, *lang
;
8694 int name_len
, inst_len
, lang_len
;
8698 * We've got a fresh USERAUTH_INFO_REQUEST.
8699 * Get the preamble and start building a prompt.
8701 ssh_pkt_getstring(pktin
, &name
, &name_len
);
8702 ssh_pkt_getstring(pktin
, &inst
, &inst_len
);
8703 ssh_pkt_getstring(pktin
, &lang
, &lang_len
);
8704 s
->cur_prompt
= new_prompts(ssh
->frontend
);
8705 s
->cur_prompt
->to_server
= TRUE
;
8708 * Get any prompt(s) from the packet.
8710 s
->num_prompts
= ssh_pkt_getuint32(pktin
);
8711 for (i
= 0; i
< s
->num_prompts
; i
++) {
8715 static char noprompt
[] =
8716 "<server failed to send prompt>: ";
8718 ssh_pkt_getstring(pktin
, &prompt
, &prompt_len
);
8719 echo
= ssh2_pkt_getbool(pktin
);
8722 prompt_len
= lenof(noprompt
)-1;
8724 add_prompt(s
->cur_prompt
,
8725 dupprintf("%.*s", prompt_len
, prompt
),
8730 /* FIXME: better prefix to distinguish from
8732 s
->cur_prompt
->name
=
8733 dupprintf("SSH server: %.*s", name_len
, name
);
8734 s
->cur_prompt
->name_reqd
= TRUE
;
8736 s
->cur_prompt
->name
=
8737 dupstr("SSH server authentication");
8738 s
->cur_prompt
->name_reqd
= FALSE
;
8740 /* We add a prefix to try to make it clear that a prompt
8741 * has come from the server.
8742 * FIXME: ugly to print "Using..." in prompt _every_
8743 * time round. Can this be done more subtly? */
8744 /* Special case: for reasons best known to themselves,
8745 * some servers send k-i requests with no prompts and
8746 * nothing to display. Keep quiet in this case. */
8747 if (s
->num_prompts
|| name_len
|| inst_len
) {
8748 s
->cur_prompt
->instruction
=
8749 dupprintf("Using keyboard-interactive authentication.%s%.*s",
8750 inst_len ?
"\n" : "", inst_len
, inst
);
8751 s
->cur_prompt
->instr_reqd
= TRUE
;
8753 s
->cur_prompt
->instr_reqd
= FALSE
;
8757 * Display any instructions, and get the user's
8761 int ret
; /* not live over crReturn */
8762 ret
= get_userpass_input(s
->cur_prompt
, NULL
, 0);
8765 crWaitUntilV(!pktin
);
8766 ret
= get_userpass_input(s
->cur_prompt
, in
, inlen
);
8771 * Failed to get responses. Terminate.
8773 free_prompts(s
->cur_prompt
);
8774 ssh_disconnect(ssh
, NULL
, "Unable to authenticate",
8775 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER
,
8782 * Send the response(s) to the server.
8784 s
->pktout
= ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE
);
8785 ssh2_pkt_adduint32(s
->pktout
, s
->num_prompts
);
8786 for (i
=0; i
< s
->num_prompts
; i
++) {
8787 dont_log_password(ssh
, s
->pktout
, PKTLOG_BLANK
);
8788 ssh2_pkt_addstring(s
->pktout
,
8789 s
->cur_prompt
->prompts
[i
]->result
);
8790 end_log_omission(ssh
, s
->pktout
);
8792 ssh2_pkt_send_with_padding(ssh
, s
->pktout
, 256);
8795 * Free the prompts structure from this iteration.
8796 * If there's another, a new one will be allocated
8797 * when we return to the top of this while loop.
8799 free_prompts(s
->cur_prompt
);
8802 * Get the next packet in case it's another
8805 crWaitUntilV(pktin
);
8810 * We should have SUCCESS or FAILURE now.
8814 } else if (s
->can_passwd
) {
8817 * Plain old password authentication.
8819 int ret
; /* not live over crReturn */
8820 int changereq_first_time
; /* not live over crReturn */
8822 ssh
->pkt_actx
= SSH2_PKTCTX_PASSWORD
;
8824 s
->cur_prompt
= new_prompts(ssh
->frontend
);
8825 s
->cur_prompt
->to_server
= TRUE
;
8826 s
->cur_prompt
->name
= dupstr("SSH password");
8827 add_prompt(s
->cur_prompt
, dupprintf("%s@%s's password: ",
8832 ret
= get_userpass_input(s
->cur_prompt
, NULL
, 0);
8835 crWaitUntilV(!pktin
);
8836 ret
= get_userpass_input(s
->cur_prompt
, in
, inlen
);
8841 * Failed to get responses. Terminate.
8843 free_prompts(s
->cur_prompt
);
8844 ssh_disconnect(ssh
, NULL
, "Unable to authenticate",
8845 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER
,
8850 * Squirrel away the password. (We may need it later if
8851 * asked to change it.)
8853 s
->password
= dupstr(s
->cur_prompt
->prompts
[0]->result
);
8854 free_prompts(s
->cur_prompt
);
8857 * Send the password packet.
8859 * We pad out the password packet to 256 bytes to make
8860 * it harder for an attacker to find the length of the
8863 * Anyone using a password longer than 256 bytes
8864 * probably doesn't have much to worry about from
8865 * people who find out how long their password is!
8867 s
->pktout
= ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
8868 ssh2_pkt_addstring(s
->pktout
, ssh
->username
);
8869 ssh2_pkt_addstring(s
->pktout
, "ssh-connection");
8870 /* service requested */
8871 ssh2_pkt_addstring(s
->pktout
, "password");
8872 ssh2_pkt_addbool(s
->pktout
, FALSE
);
8873 dont_log_password(ssh
, s
->pktout
, PKTLOG_BLANK
);
8874 ssh2_pkt_addstring(s
->pktout
, s
->password
);
8875 end_log_omission(ssh
, s
->pktout
);
8876 ssh2_pkt_send_with_padding(ssh
, s
->pktout
, 256);
8877 logevent("Sent password");
8878 s
->type
= AUTH_TYPE_PASSWORD
;
8881 * Wait for next packet, in case it's a password change
8884 crWaitUntilV(pktin
);
8885 changereq_first_time
= TRUE
;
8887 while (pktin
->type
== SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ
) {
8890 * We're being asked for a new password
8891 * (perhaps not for the first time).
8892 * Loop until the server accepts it.
8895 int got_new
= FALSE
; /* not live over crReturn */
8896 char *prompt
; /* not live over crReturn */
8897 int prompt_len
; /* not live over crReturn */
8901 if (changereq_first_time
)
8902 msg
= "Server requested password change";
8904 msg
= "Server rejected new password";
8906 c_write_str(ssh
, msg
);
8907 c_write_str(ssh
, "\r\n");
8910 ssh_pkt_getstring(pktin
, &prompt
, &prompt_len
);
8912 s
->cur_prompt
= new_prompts(ssh
->frontend
);
8913 s
->cur_prompt
->to_server
= TRUE
;
8914 s
->cur_prompt
->name
= dupstr("New SSH password");
8915 s
->cur_prompt
->instruction
=
8916 dupprintf("%.*s", prompt_len
, prompt
);
8917 s
->cur_prompt
->instr_reqd
= TRUE
;
8919 * There's no explicit requirement in the protocol
8920 * for the "old" passwords in the original and
8921 * password-change messages to be the same, and
8922 * apparently some Cisco kit supports password change
8923 * by the user entering a blank password originally
8924 * and the real password subsequently, so,
8925 * reluctantly, we prompt for the old password again.
8927 * (On the other hand, some servers don't even bother
8928 * to check this field.)
8930 add_prompt(s
->cur_prompt
,
8931 dupstr("Current password (blank for previously entered password): "),
8933 add_prompt(s
->cur_prompt
, dupstr("Enter new password: "),
8935 add_prompt(s
->cur_prompt
, dupstr("Confirm new password: "),
8939 * Loop until the user manages to enter the same
8944 ret
= get_userpass_input(s
->cur_prompt
, NULL
, 0);
8947 crWaitUntilV(!pktin
);
8948 ret
= get_userpass_input(s
->cur_prompt
, in
, inlen
);
8953 * Failed to get responses. Terminate.
8955 /* burn the evidence */
8956 free_prompts(s
->cur_prompt
);
8957 smemclr(s
->password
, strlen(s
->password
));
8959 ssh_disconnect(ssh
, NULL
, "Unable to authenticate",
8960 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER
,
8966 * If the user specified a new original password
8967 * (IYSWIM), overwrite any previously specified
8969 * (A side effect is that the user doesn't have to
8970 * re-enter it if they louse up the new password.)
8972 if (s
->cur_prompt
->prompts
[0]->result
[0]) {
8973 smemclr(s
->password
, strlen(s
->password
));
8974 /* burn the evidence */
8977 dupstr(s
->cur_prompt
->prompts
[0]->result
);
8981 * Check the two new passwords match.
8983 got_new
= (strcmp(s
->cur_prompt
->prompts
[1]->result
,
8984 s
->cur_prompt
->prompts
[2]->result
)
8987 /* They don't. Silly user. */
8988 c_write_str(ssh
, "Passwords do not match\r\n");
8993 * Send the new password (along with the old one).
8994 * (see above for padding rationale)
8996 s
->pktout
= ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
8997 ssh2_pkt_addstring(s
->pktout
, ssh
->username
);
8998 ssh2_pkt_addstring(s
->pktout
, "ssh-connection");
8999 /* service requested */
9000 ssh2_pkt_addstring(s
->pktout
, "password");
9001 ssh2_pkt_addbool(s
->pktout
, TRUE
);
9002 dont_log_password(ssh
, s
->pktout
, PKTLOG_BLANK
);
9003 ssh2_pkt_addstring(s
->pktout
, s
->password
);
9004 ssh2_pkt_addstring(s
->pktout
,
9005 s
->cur_prompt
->prompts
[1]->result
);
9006 free_prompts(s
->cur_prompt
);
9007 end_log_omission(ssh
, s
->pktout
);
9008 ssh2_pkt_send_with_padding(ssh
, s
->pktout
, 256);
9009 logevent("Sent new password");
9012 * Now see what the server has to say about it.
9013 * (If it's CHANGEREQ again, it's not happy with the
9016 crWaitUntilV(pktin
);
9017 changereq_first_time
= FALSE
;
9022 * We need to reexamine the current pktin at the top
9023 * of the loop. Either:
9024 * - we weren't asked to change password at all, in
9025 * which case it's a SUCCESS or FAILURE with the
9027 * - we sent a new password, and the server was
9028 * either OK with it (SUCCESS or FAILURE w/partial
9029 * success) or unhappy with the _old_ password
9030 * (FAILURE w/o partial success)
9031 * In any of these cases, we go back to the top of
9032 * the loop and start again.
9037 * We don't need the old password any more, in any
9038 * case. Burn the evidence.
9040 smemclr(s
->password
, strlen(s
->password
));
9044 char *str
= dupprintf("No supported authentication methods available"
9045 " (server sent: %.*s)",
9048 ssh_disconnect(ssh
, str
,
9049 "No supported authentication methods available",
9050 SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE
,
9060 ssh
->packet_dispatch
[SSH2_MSG_USERAUTH_BANNER
] = NULL
;
9062 /* Clear up various bits and pieces from authentication. */
9063 if (s
->publickey_blob
) {
9064 sfree(s
->publickey_blob
);
9065 sfree(s
->publickey_comment
);
9067 if (s
->agent_response
)
9068 sfree(s
->agent_response
);
9070 if (s
->userauth_success
) {
9072 * We've just received USERAUTH_SUCCESS, and we haven't sent any
9073 * packets since. Signal the transport layer to consider enacting
9074 * delayed compression.
9076 * (Relying on we_are_in is not sufficient, as
9077 * draft-miller-secsh-compression-delayed is quite clear that it
9078 * triggers on USERAUTH_SUCCESS specifically, and we_are_in can
9079 * become set for other reasons.)
9081 do_ssh2_transport(ssh
, "enabling delayed compression", -2, NULL
);
9085 * Now the connection protocol has started, one way or another.
9088 ssh
->channels
= newtree234(ssh_channelcmp
);
9091 * Set up handlers for some connection protocol messages, so we
9092 * don't have to handle them repeatedly in this coroutine.
9094 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_WINDOW_ADJUST
] =
9095 ssh2_msg_channel_window_adjust
;
9096 ssh
->packet_dispatch
[SSH2_MSG_GLOBAL_REQUEST
] =
9097 ssh2_msg_global_request
;
9100 * Create the main session channel.
9102 if (conf_get_int(ssh
->conf
, CONF_ssh_no_shell
)) {
9103 ssh
->mainchan
= NULL
;
9104 } else if (*conf_get_str(ssh
->conf
, CONF_ssh_nc_host
)) {
9106 * Just start a direct-tcpip channel and use it as the main
9109 ssh
->mainchan
= snew(struct ssh_channel
);
9110 ssh
->mainchan
->ssh
= ssh
;
9111 ssh2_channel_init(ssh
->mainchan
);
9113 "Opening direct-tcpip channel to %s:%d in place of session",
9114 conf_get_str(ssh
->conf
, CONF_ssh_nc_host
),
9115 conf_get_int(ssh
->conf
, CONF_ssh_nc_port
));
9116 s
->pktout
= ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN
);
9117 ssh2_pkt_addstring(s
->pktout
, "direct-tcpip");
9118 ssh2_pkt_adduint32(s
->pktout
, ssh
->mainchan
->localid
);
9119 ssh2_pkt_adduint32(s
->pktout
, ssh
->mainchan
->v
.v2
.locwindow
);/* our window size */
9120 ssh2_pkt_adduint32(s
->pktout
, OUR_V2_MAXPKT
); /* our max pkt size */
9121 ssh2_pkt_addstring(s
->pktout
, conf_get_str(ssh
->conf
, CONF_ssh_nc_host
));
9122 ssh2_pkt_adduint32(s
->pktout
, conf_get_int(ssh
->conf
, CONF_ssh_nc_port
));
9124 * There's nothing meaningful to put in the originator
9125 * fields, but some servers insist on syntactically correct
9128 ssh2_pkt_addstring(s
->pktout
, "0.0.0.0");
9129 ssh2_pkt_adduint32(s
->pktout
, 0);
9130 ssh2_pkt_send(ssh
, s
->pktout
);
9132 crWaitUntilV(pktin
);
9133 if (pktin
->type
!= SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
) {
9134 bombout(("Server refused to open a direct-tcpip channel"));
9136 /* FIXME: error data comes back in FAILURE packet */
9138 if (ssh_pkt_getuint32(pktin
) != ssh
->mainchan
->localid
) {
9139 bombout(("Server's channel confirmation cited wrong channel"));
9142 ssh
->mainchan
->remoteid
= ssh_pkt_getuint32(pktin
);
9143 ssh
->mainchan
->halfopen
= FALSE
;
9144 ssh
->mainchan
->type
= CHAN_MAINSESSION
;
9145 ssh
->mainchan
->v
.v2
.remwindow
= ssh_pkt_getuint32(pktin
);
9146 ssh
->mainchan
->v
.v2
.remmaxpkt
= ssh_pkt_getuint32(pktin
);
9147 add234(ssh
->channels
, ssh
->mainchan
);
9148 update_specials_menu(ssh
->frontend
);
9149 logevent("Opened direct-tcpip channel");
9152 ssh
->mainchan
= snew(struct ssh_channel
);
9153 ssh
->mainchan
->ssh
= ssh
;
9154 ssh2_channel_init(ssh
->mainchan
);
9155 s
->pktout
= ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN
);
9156 ssh2_pkt_addstring(s
->pktout
, "session");
9157 ssh2_pkt_adduint32(s
->pktout
, ssh
->mainchan
->localid
);
9158 ssh2_pkt_adduint32(s
->pktout
, ssh
->mainchan
->v
.v2
.locwindow
);/* our window size */
9159 ssh2_pkt_adduint32(s
->pktout
, OUR_V2_MAXPKT
); /* our max pkt size */
9160 ssh2_pkt_send(ssh
, s
->pktout
);
9161 crWaitUntilV(pktin
);
9162 if (pktin
->type
!= SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
) {
9163 bombout(("Server refused to open a session"));
9165 /* FIXME: error data comes back in FAILURE packet */
9167 if (ssh_pkt_getuint32(pktin
) != ssh
->mainchan
->localid
) {
9168 bombout(("Server's channel confirmation cited wrong channel"));
9171 ssh
->mainchan
->remoteid
= ssh_pkt_getuint32(pktin
);
9172 ssh
->mainchan
->halfopen
= FALSE
;
9173 ssh
->mainchan
->type
= CHAN_MAINSESSION
;
9174 ssh
->mainchan
->v
.v2
.remwindow
= ssh_pkt_getuint32(pktin
);
9175 ssh
->mainchan
->v
.v2
.remmaxpkt
= ssh_pkt_getuint32(pktin
);
9176 add234(ssh
->channels
, ssh
->mainchan
);
9177 update_specials_menu(ssh
->frontend
);
9178 logevent("Opened channel for session");
9179 ssh
->ncmode
= FALSE
;
9183 * Now we have a channel, make dispatch table entries for
9184 * general channel-based messages.
9186 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_DATA
] =
9187 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_EXTENDED_DATA
] =
9188 ssh2_msg_channel_data
;
9189 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_EOF
] = ssh2_msg_channel_eof
;
9190 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_CLOSE
] = ssh2_msg_channel_close
;
9191 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
] =
9192 ssh2_msg_channel_open_confirmation
;
9193 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_OPEN_FAILURE
] =
9194 ssh2_msg_channel_open_failure
;
9195 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_REQUEST
] =
9196 ssh2_msg_channel_request
;
9197 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_OPEN
] =
9198 ssh2_msg_channel_open
;
9199 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_SUCCESS
] = ssh2_msg_channel_response
;
9200 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_FAILURE
] = ssh2_msg_channel_response
;
9203 if (ssh
->mainchan
&& conf_get_int(ssh
->conf
, CONF_ssh_simple
)) {
9205 * This message indicates to the server that we promise
9206 * not to try to run any other channel in parallel with
9207 * this one, so it's safe for it to advertise a very large
9208 * window and leave the flow control to TCP.
9210 s
->pktout
= ssh2_chanreq_init(ssh
->mainchan
,
9211 "simple@putty.projects.tartarus.org",
9213 ssh2_pkt_send(ssh
, s
->pktout
);
9217 * Enable port forwardings.
9219 ssh_setup_portfwd(ssh
, ssh
->conf
);
9221 if (ssh
->mainchan
&& !ssh
->ncmode
) {
9223 * Send the CHANNEL_REQUESTS for the main session channel.
9224 * Each one is handled by its own little asynchronous
9228 /* Potentially enable X11 forwarding. */
9229 if (conf_get_int(ssh
->conf
, CONF_x11_forward
) &&
9231 x11_setup_display(conf_get_str(ssh
->conf
, CONF_x11_display
),
9232 conf_get_int(ssh
->conf
, CONF_x11_auth
),
9234 ssh2_setup_x11(ssh
->mainchan
, NULL
, NULL
);
9236 /* Potentially enable agent forwarding. */
9237 if (conf_get_int(ssh
->conf
, CONF_agentfwd
) && agent_exists())
9238 ssh2_setup_agent(ssh
->mainchan
, NULL
, NULL
);
9240 /* Now allocate a pty for the session. */
9241 if (!conf_get_int(ssh
->conf
, CONF_nopty
))
9242 ssh2_setup_pty(ssh
->mainchan
, NULL
, NULL
);
9244 /* Send environment variables. */
9245 ssh2_setup_env(ssh
->mainchan
, NULL
, NULL
);
9248 * Start a shell or a remote command. We may have to attempt
9249 * this twice if the config data has provided a second choice
9256 if (ssh
->fallback_cmd
) {
9257 subsys
= conf_get_int(ssh
->conf
, CONF_ssh_subsys2
);
9258 cmd
= conf_get_str(ssh
->conf
, CONF_remote_cmd2
);
9260 subsys
= conf_get_int(ssh
->conf
, CONF_ssh_subsys
);
9261 cmd
= conf_get_str(ssh
->conf
, CONF_remote_cmd
);
9265 s
->pktout
= ssh2_chanreq_init(ssh
->mainchan
, "subsystem",
9266 ssh2_response_authconn
, NULL
);
9267 ssh2_pkt_addstring(s
->pktout
, cmd
);
9269 s
->pktout
= ssh2_chanreq_init(ssh
->mainchan
, "exec",
9270 ssh2_response_authconn
, NULL
);
9271 ssh2_pkt_addstring(s
->pktout
, cmd
);
9273 s
->pktout
= ssh2_chanreq_init(ssh
->mainchan
, "shell",
9274 ssh2_response_authconn
, NULL
);
9276 ssh2_pkt_send(ssh
, s
->pktout
);
9278 crWaitUntilV(pktin
);
9280 if (pktin
->type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
9281 if (pktin
->type
!= SSH2_MSG_CHANNEL_FAILURE
) {
9282 bombout(("Unexpected response to shell/command request:"
9283 " packet type %d", pktin
->type
));
9287 * We failed to start the command. If this is the
9288 * fallback command, we really are finished; if it's
9289 * not, and if the fallback command exists, try falling
9290 * back to it before complaining.
9292 if (!ssh
->fallback_cmd
&&
9293 *conf_get_str(ssh
->conf
, CONF_remote_cmd2
)) {
9294 logevent("Primary command failed; attempting fallback");
9295 ssh
->fallback_cmd
= TRUE
;
9298 bombout(("Server refused to start a shell/command"));
9301 logevent("Started a shell/command");
9306 ssh
->editing
= ssh
->echoing
= TRUE
;
9309 ssh
->state
= SSH_STATE_SESSION
;
9310 if (ssh
->size_needed
)
9311 ssh_size(ssh
, ssh
->term_width
, ssh
->term_height
);
9312 if (ssh
->eof_needed
)
9313 ssh_special(ssh
, TS_EOF
);
9319 ldisc_send(ssh
->ldisc
, NULL
, 0, 0);/* cause ldisc to notice changes */
9324 s
->try_send
= FALSE
;
9328 * _All_ the connection-layer packets we expect to
9329 * receive are now handled by the dispatch table.
9330 * Anything that reaches here must be bogus.
9333 bombout(("Strange packet received: type %d", pktin
->type
));
9335 } else if (ssh
->mainchan
) {
9337 * We have spare data. Add it to the channel buffer.
9339 ssh2_add_channel_data(ssh
->mainchan
, (char *)in
, inlen
);
9344 struct ssh_channel
*c
;
9346 * Try to send data on all channels if we can.
9348 for (i
= 0; NULL
!= (c
= index234(ssh
->channels
, i
)); i
++)
9349 ssh2_try_send_and_unthrottle(ssh
, c
);
9357 * Handlers for SSH-2 messages that might arrive at any moment.
9359 static void ssh2_msg_disconnect(Ssh ssh
, struct Packet
*pktin
)
9361 /* log reason code in disconnect message */
9365 reason
= ssh_pkt_getuint32(pktin
);
9366 ssh_pkt_getstring(pktin
, &msg
, &msglen
);
9368 if (reason
> 0 && reason
< lenof(ssh2_disconnect_reasons
)) {
9369 buf
= dupprintf("Received disconnect message (%s)",
9370 ssh2_disconnect_reasons
[reason
]);
9372 buf
= dupprintf("Received disconnect message (unknown"
9373 " type %d)", reason
);
9377 buf
= dupprintf("Disconnection message text: %.*s",
9380 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%.*s\"",
9382 (reason
> 0 && reason
< lenof(ssh2_disconnect_reasons
)) ?
9383 ssh2_disconnect_reasons
[reason
] : "unknown",
9388 static void ssh2_msg_debug(Ssh ssh
, struct Packet
*pktin
)
9390 /* log the debug message */
9394 /* XXX maybe we should actually take notice of the return value */
9395 ssh2_pkt_getbool(pktin
);
9396 ssh_pkt_getstring(pktin
, &msg
, &msglen
);
9398 logeventf(ssh
, "Remote debug message: %.*s", msglen
, msg
);
9401 static void ssh2_msg_transport(Ssh ssh
, struct Packet
*pktin
)
9403 do_ssh2_transport(ssh
, NULL
, 0, pktin
);
9407 * Called if we receive a packet that isn't allowed by the protocol.
9408 * This only applies to packets whose meaning PuTTY understands.
9409 * Entirely unknown packets are handled below.
9411 static void ssh2_msg_unexpected(Ssh ssh
, struct Packet
*pktin
)
9413 char *buf
= dupprintf("Server protocol violation: unexpected %s packet",
9414 ssh2_pkt_type(ssh
->pkt_kctx
, ssh
->pkt_actx
,
9416 ssh_disconnect(ssh
, NULL
, buf
, SSH2_DISCONNECT_PROTOCOL_ERROR
, FALSE
);
9420 static void ssh2_msg_something_unimplemented(Ssh ssh
, struct Packet
*pktin
)
9422 struct Packet
*pktout
;
9423 pktout
= ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED
);
9424 ssh2_pkt_adduint32(pktout
, pktin
->sequence
);
9426 * UNIMPLEMENTED messages MUST appear in the same order as the
9427 * messages they respond to. Hence, never queue them.
9429 ssh2_pkt_send_noqueue(ssh
, pktout
);
9433 * Handle the top-level SSH-2 protocol.
9435 static void ssh2_protocol_setup(Ssh ssh
)
9440 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
9442 for (i
= 0; i
< 256; i
++)
9443 ssh
->packet_dispatch
[i
] = ssh2_msg_something_unimplemented
;
9446 * Initially, we only accept transport messages (and a few generic
9447 * ones). do_ssh2_authconn will add more when it starts.
9448 * Messages that are understood but not currently acceptable go to
9449 * ssh2_msg_unexpected.
9451 ssh
->packet_dispatch
[SSH2_MSG_UNIMPLEMENTED
] = ssh2_msg_unexpected
;
9452 ssh
->packet_dispatch
[SSH2_MSG_SERVICE_REQUEST
] = ssh2_msg_unexpected
;
9453 ssh
->packet_dispatch
[SSH2_MSG_SERVICE_ACCEPT
] = ssh2_msg_unexpected
;
9454 ssh
->packet_dispatch
[SSH2_MSG_KEXINIT
] = ssh2_msg_transport
;
9455 ssh
->packet_dispatch
[SSH2_MSG_NEWKEYS
] = ssh2_msg_transport
;
9456 ssh
->packet_dispatch
[SSH2_MSG_KEXDH_INIT
] = ssh2_msg_transport
;
9457 ssh
->packet_dispatch
[SSH2_MSG_KEXDH_REPLY
] = ssh2_msg_transport
;
9458 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = ssh2_msg_transport; duplicate case value */
9459 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = ssh2_msg_transport; duplicate case value */
9460 ssh
->packet_dispatch
[SSH2_MSG_KEX_DH_GEX_INIT
] = ssh2_msg_transport
;
9461 ssh
->packet_dispatch
[SSH2_MSG_KEX_DH_GEX_REPLY
] = ssh2_msg_transport
;
9462 ssh
->packet_dispatch
[SSH2_MSG_USERAUTH_REQUEST
] = ssh2_msg_unexpected
;
9463 ssh
->packet_dispatch
[SSH2_MSG_USERAUTH_FAILURE
] = ssh2_msg_unexpected
;
9464 ssh
->packet_dispatch
[SSH2_MSG_USERAUTH_SUCCESS
] = ssh2_msg_unexpected
;
9465 ssh
->packet_dispatch
[SSH2_MSG_USERAUTH_BANNER
] = ssh2_msg_unexpected
;
9466 ssh
->packet_dispatch
[SSH2_MSG_USERAUTH_PK_OK
] = ssh2_msg_unexpected
;
9467 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = ssh2_msg_unexpected; duplicate case value */
9468 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = ssh2_msg_unexpected; duplicate case value */
9469 ssh
->packet_dispatch
[SSH2_MSG_USERAUTH_INFO_RESPONSE
] = ssh2_msg_unexpected
;
9470 ssh
->packet_dispatch
[SSH2_MSG_GLOBAL_REQUEST
] = ssh2_msg_unexpected
;
9471 ssh
->packet_dispatch
[SSH2_MSG_REQUEST_SUCCESS
] = ssh2_msg_unexpected
;
9472 ssh
->packet_dispatch
[SSH2_MSG_REQUEST_FAILURE
] = ssh2_msg_unexpected
;
9473 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_OPEN
] = ssh2_msg_unexpected
;
9474 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
] = ssh2_msg_unexpected
;
9475 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_OPEN_FAILURE
] = ssh2_msg_unexpected
;
9476 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_WINDOW_ADJUST
] = ssh2_msg_unexpected
;
9477 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_DATA
] = ssh2_msg_unexpected
;
9478 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_EXTENDED_DATA
] = ssh2_msg_unexpected
;
9479 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_EOF
] = ssh2_msg_unexpected
;
9480 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_CLOSE
] = ssh2_msg_unexpected
;
9481 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_REQUEST
] = ssh2_msg_unexpected
;
9482 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_SUCCESS
] = ssh2_msg_unexpected
;
9483 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_FAILURE
] = ssh2_msg_unexpected
;
9486 * These messages have a special handler from the start.
9488 ssh
->packet_dispatch
[SSH2_MSG_DISCONNECT
] = ssh2_msg_disconnect
;
9489 ssh
->packet_dispatch
[SSH2_MSG_IGNORE
] = ssh_msg_ignore
; /* shared with SSH-1 */
9490 ssh
->packet_dispatch
[SSH2_MSG_DEBUG
] = ssh2_msg_debug
;
9493 static void ssh2_timer(void *ctx
, long now
)
9497 if (ssh
->state
== SSH_STATE_CLOSED
)
9500 if (!ssh
->kex_in_progress
&& conf_get_int(ssh
->conf
, CONF_ssh_rekey_time
) != 0 &&
9501 now
- ssh
->next_rekey
>= 0) {
9502 do_ssh2_transport(ssh
, "timeout", -1, NULL
);
9506 static void ssh2_protocol(Ssh ssh
, void *vin
, int inlen
,
9507 struct Packet
*pktin
)
9509 unsigned char *in
= (unsigned char *)vin
;
9510 if (ssh
->state
== SSH_STATE_CLOSED
)
9514 ssh
->incoming_data_size
+= pktin
->encrypted_len
;
9515 if (!ssh
->kex_in_progress
&&
9516 ssh
->max_data_size
!= 0 &&
9517 ssh
->incoming_data_size
> ssh
->max_data_size
)
9518 do_ssh2_transport(ssh
, "too much data received", -1, NULL
);
9522 ssh
->packet_dispatch
[pktin
->type
](ssh
, pktin
);
9523 else if (!ssh
->protocol_initial_phase_done
)
9524 do_ssh2_transport(ssh
, in
, inlen
, pktin
);
9526 do_ssh2_authconn(ssh
, in
, inlen
, pktin
);
9529 static void ssh_cache_conf_values(Ssh ssh
)
9531 ssh
->logomitdata
= conf_get_int(ssh
->conf
, CONF_logomitdata
);
9535 * Called to set up the connection.
9537 * Returns an error message, or NULL on success.
9539 static const char *ssh_init(void *frontend_handle
, void **backend_handle
,
9540 Conf
*conf
, char *host
, int port
, char **realhost
,
9541 int nodelay
, int keepalive
)
9546 ssh
= snew(struct ssh_tag
);
9547 ssh
->conf
= conf_copy(conf
);
9548 ssh_cache_conf_values(ssh
);
9549 ssh
->version
= 0; /* when not ready yet */
9552 ssh
->v1_cipher_ctx
= NULL
;
9553 ssh
->crcda_ctx
= NULL
;
9554 ssh
->cscipher
= NULL
;
9555 ssh
->cs_cipher_ctx
= NULL
;
9556 ssh
->sccipher
= NULL
;
9557 ssh
->sc_cipher_ctx
= NULL
;
9559 ssh
->cs_mac_ctx
= NULL
;
9561 ssh
->sc_mac_ctx
= NULL
;
9563 ssh
->cs_comp_ctx
= NULL
;
9565 ssh
->sc_comp_ctx
= NULL
;
9567 ssh
->kex_ctx
= NULL
;
9568 ssh
->hostkey
= NULL
;
9570 ssh
->close_expected
= FALSE
;
9571 ssh
->clean_exit
= FALSE
;
9572 ssh
->state
= SSH_STATE_PREPACKET
;
9573 ssh
->size_needed
= FALSE
;
9574 ssh
->eof_needed
= FALSE
;
9577 ssh
->deferred_send_data
= NULL
;
9578 ssh
->deferred_len
= 0;
9579 ssh
->deferred_size
= 0;
9580 ssh
->fallback_cmd
= 0;
9581 ssh
->pkt_kctx
= SSH2_PKTCTX_NOKEX
;
9582 ssh
->pkt_actx
= SSH2_PKTCTX_NOAUTH
;
9583 ssh
->x11disp
= NULL
;
9584 ssh
->v1_compressing
= FALSE
;
9585 ssh
->v2_outgoing_sequence
= 0;
9586 ssh
->ssh1_rdpkt_crstate
= 0;
9587 ssh
->ssh2_rdpkt_crstate
= 0;
9588 ssh
->ssh_gotdata_crstate
= 0;
9589 ssh
->do_ssh1_connection_crstate
= 0;
9590 ssh
->do_ssh_init_state
= NULL
;
9591 ssh
->do_ssh1_login_state
= NULL
;
9592 ssh
->do_ssh2_transport_state
= NULL
;
9593 ssh
->do_ssh2_authconn_state
= NULL
;
9596 ssh
->mainchan
= NULL
;
9597 ssh
->throttled_all
= 0;
9598 ssh
->v1_stdout_throttling
= 0;
9600 ssh
->queuelen
= ssh
->queuesize
= 0;
9601 ssh
->queueing
= FALSE
;
9602 ssh
->qhead
= ssh
->qtail
= NULL
;
9603 ssh
->deferred_rekey_reason
= NULL
;
9604 bufchain_init(&ssh
->queued_incoming_data
);
9605 ssh
->frozen
= FALSE
;
9606 ssh
->username
= NULL
;
9607 ssh
->sent_console_eof
= FALSE
;
9608 ssh
->got_pty
= FALSE
;
9610 *backend_handle
= ssh
;
9613 if (crypto_startup() == 0)
9614 return "Microsoft high encryption pack not installed!";
9617 ssh
->frontend
= frontend_handle
;
9618 ssh
->term_width
= conf_get_int(ssh
->conf
, CONF_width
);
9619 ssh
->term_height
= conf_get_int(ssh
->conf
, CONF_height
);
9621 ssh
->channels
= NULL
;
9622 ssh
->rportfwds
= NULL
;
9623 ssh
->portfwds
= NULL
;
9628 ssh
->conn_throttle_count
= 0;
9629 ssh
->overall_bufsize
= 0;
9630 ssh
->fallback_cmd
= 0;
9632 ssh
->protocol
= NULL
;
9634 ssh
->protocol_initial_phase_done
= FALSE
;
9638 ssh
->incoming_data_size
= ssh
->outgoing_data_size
=
9639 ssh
->deferred_data_size
= 0L;
9640 ssh
->max_data_size
= parse_blocksize(conf_get_str(ssh
->conf
,
9641 CONF_ssh_rekey_data
));
9642 ssh
->kex_in_progress
= FALSE
;
9645 ssh
->gsslibs
= NULL
;
9648 p
= connect_to_host(ssh
, host
, port
, realhost
, nodelay
, keepalive
);
9657 static void ssh_free(void *handle
)
9659 Ssh ssh
= (Ssh
) handle
;
9660 struct ssh_channel
*c
;
9661 struct ssh_rportfwd
*pf
;
9663 if (ssh
->v1_cipher_ctx
)
9664 ssh
->cipher
->free_context(ssh
->v1_cipher_ctx
);
9665 if (ssh
->cs_cipher_ctx
)
9666 ssh
->cscipher
->free_context(ssh
->cs_cipher_ctx
);
9667 if (ssh
->sc_cipher_ctx
)
9668 ssh
->sccipher
->free_context(ssh
->sc_cipher_ctx
);
9669 if (ssh
->cs_mac_ctx
)
9670 ssh
->csmac
->free_context(ssh
->cs_mac_ctx
);
9671 if (ssh
->sc_mac_ctx
)
9672 ssh
->scmac
->free_context(ssh
->sc_mac_ctx
);
9673 if (ssh
->cs_comp_ctx
) {
9675 ssh
->cscomp
->compress_cleanup(ssh
->cs_comp_ctx
);
9677 zlib_compress_cleanup(ssh
->cs_comp_ctx
);
9679 if (ssh
->sc_comp_ctx
) {
9681 ssh
->sccomp
->decompress_cleanup(ssh
->sc_comp_ctx
);
9683 zlib_decompress_cleanup(ssh
->sc_comp_ctx
);
9686 dh_cleanup(ssh
->kex_ctx
);
9687 sfree(ssh
->savedhost
);
9689 while (ssh
->queuelen
-- > 0)
9690 ssh_free_packet(ssh
->queue
[ssh
->queuelen
]);
9693 while (ssh
->qhead
) {
9694 struct queued_handler
*qh
= ssh
->qhead
;
9695 ssh
->qhead
= qh
->next
;
9698 ssh
->qhead
= ssh
->qtail
= NULL
;
9700 if (ssh
->channels
) {
9701 while ((c
= delpos234(ssh
->channels
, 0)) != NULL
) {
9704 if (c
->u
.x11
.s
!= NULL
)
9705 x11_close(c
->u
.x11
.s
);
9708 case CHAN_SOCKDATA_DORMANT
:
9709 if (c
->u
.pfd
.s
!= NULL
)
9710 pfd_close(c
->u
.pfd
.s
);
9713 if (ssh
->version
== 2) {
9714 struct outstanding_channel_request
*ocr
, *nocr
;
9715 ocr
= c
->v
.v2
.chanreq_head
;
9717 ocr
->handler(c
, NULL
, ocr
->ctx
);
9722 bufchain_clear(&c
->v
.v2
.outbuffer
);
9726 freetree234(ssh
->channels
);
9727 ssh
->channels
= NULL
;
9730 if (ssh
->rportfwds
) {
9731 while ((pf
= delpos234(ssh
->rportfwds
, 0)) != NULL
)
9733 freetree234(ssh
->rportfwds
);
9734 ssh
->rportfwds
= NULL
;
9736 sfree(ssh
->deferred_send_data
);
9738 x11_free_display(ssh
->x11disp
);
9739 sfree(ssh
->do_ssh_init_state
);
9740 sfree(ssh
->do_ssh1_login_state
);
9741 sfree(ssh
->do_ssh2_transport_state
);
9742 sfree(ssh
->do_ssh2_authconn_state
);
9745 sfree(ssh
->fullhostname
);
9746 if (ssh
->crcda_ctx
) {
9747 crcda_free_context(ssh
->crcda_ctx
);
9748 ssh
->crcda_ctx
= NULL
;
9751 ssh_do_close(ssh
, TRUE
);
9752 expire_timer_context(ssh
);
9754 pinger_free(ssh
->pinger
);
9755 bufchain_clear(&ssh
->queued_incoming_data
);
9756 sfree(ssh
->username
);
9757 conf_free(ssh
->conf
);
9760 ssh_gss_cleanup(ssh
->gsslibs
);
9768 * Reconfigure the SSH backend.
9770 static void ssh_reconfig(void *handle
, Conf
*conf
)
9772 Ssh ssh
= (Ssh
) handle
;
9773 char *rekeying
= NULL
, rekey_mandatory
= FALSE
;
9774 unsigned long old_max_data_size
;
9777 pinger_reconfig(ssh
->pinger
, ssh
->conf
, conf
);
9779 ssh_setup_portfwd(ssh
, conf
);
9781 rekey_time
= conf_get_int(conf
, CONF_ssh_rekey_time
);
9782 if (conf_get_int(ssh
->conf
, CONF_ssh_rekey_time
) != rekey_time
&&
9784 long new_next
= ssh
->last_rekey
+ rekey_time
*60*TICKSPERSEC
;
9785 long now
= GETTICKCOUNT();
9787 if (new_next
- now
< 0) {
9788 rekeying
= "timeout shortened";
9790 ssh
->next_rekey
= schedule_timer(new_next
- now
, ssh2_timer
, ssh
);
9794 old_max_data_size
= ssh
->max_data_size
;
9795 ssh
->max_data_size
= parse_blocksize(conf_get_str(ssh
->conf
,
9796 CONF_ssh_rekey_data
));
9797 if (old_max_data_size
!= ssh
->max_data_size
&&
9798 ssh
->max_data_size
!= 0) {
9799 if (ssh
->outgoing_data_size
> ssh
->max_data_size
||
9800 ssh
->incoming_data_size
> ssh
->max_data_size
)
9801 rekeying
= "data limit lowered";
9804 if (conf_get_int(ssh
->conf
, CONF_compression
) !=
9805 conf_get_int(conf
, CONF_compression
)) {
9806 rekeying
= "compression setting changed";
9807 rekey_mandatory
= TRUE
;
9810 for (i
= 0; i
< CIPHER_MAX
; i
++)
9811 if (conf_get_int_int(ssh
->conf
, CONF_ssh_cipherlist
, i
) !=
9812 conf_get_int_int(conf
, CONF_ssh_cipherlist
, i
)) {
9813 rekeying
= "cipher settings changed";
9814 rekey_mandatory
= TRUE
;
9816 if (conf_get_int(ssh
->conf
, CONF_ssh2_des_cbc
) !=
9817 conf_get_int(conf
, CONF_ssh2_des_cbc
)) {
9818 rekeying
= "cipher settings changed";
9819 rekey_mandatory
= TRUE
;
9822 conf_free(ssh
->conf
);
9823 ssh
->conf
= conf_copy(conf
);
9824 ssh_cache_conf_values(ssh
);
9827 if (!ssh
->kex_in_progress
) {
9828 do_ssh2_transport(ssh
, rekeying
, -1, NULL
);
9829 } else if (rekey_mandatory
) {
9830 ssh
->deferred_rekey_reason
= rekeying
;
9836 * Called to send data down the SSH connection.
9838 static int ssh_send(void *handle
, char *buf
, int len
)
9840 Ssh ssh
= (Ssh
) handle
;
9842 if (ssh
== NULL
|| ssh
->s
== NULL
|| ssh
->protocol
== NULL
)
9845 ssh
->protocol(ssh
, (unsigned char *)buf
, len
, 0);
9847 return ssh_sendbuffer(ssh
);
9851 * Called to query the current amount of buffered stdin data.
9853 static int ssh_sendbuffer(void *handle
)
9855 Ssh ssh
= (Ssh
) handle
;
9858 if (ssh
== NULL
|| ssh
->s
== NULL
|| ssh
->protocol
== NULL
)
9862 * If the SSH socket itself has backed up, add the total backup
9863 * size on that to any individual buffer on the stdin channel.
9866 if (ssh
->throttled_all
)
9867 override_value
= ssh
->overall_bufsize
;
9869 if (ssh
->version
== 1) {
9870 return override_value
;
9871 } else if (ssh
->version
== 2) {
9873 return override_value
;
9875 return (override_value
+
9876 bufchain_size(&ssh
->mainchan
->v
.v2
.outbuffer
));
9883 * Called to set the size of the window from SSH's POV.
9885 static void ssh_size(void *handle
, int width
, int height
)
9887 Ssh ssh
= (Ssh
) handle
;
9888 struct Packet
*pktout
;
9890 ssh
->term_width
= width
;
9891 ssh
->term_height
= height
;
9893 switch (ssh
->state
) {
9894 case SSH_STATE_BEFORE_SIZE
:
9895 case SSH_STATE_PREPACKET
:
9896 case SSH_STATE_CLOSED
:
9897 break; /* do nothing */
9898 case SSH_STATE_INTERMED
:
9899 ssh
->size_needed
= TRUE
; /* buffer for later */
9901 case SSH_STATE_SESSION
:
9902 if (!conf_get_int(ssh
->conf
, CONF_nopty
)) {
9903 if (ssh
->version
== 1) {
9904 send_packet(ssh
, SSH1_CMSG_WINDOW_SIZE
,
9905 PKT_INT
, ssh
->term_height
,
9906 PKT_INT
, ssh
->term_width
,
9907 PKT_INT
, 0, PKT_INT
, 0, PKT_END
);
9908 } else if (ssh
->mainchan
) {
9909 pktout
= ssh2_chanreq_init(ssh
->mainchan
, "window-change",
9911 ssh2_pkt_adduint32(pktout
, ssh
->term_width
);
9912 ssh2_pkt_adduint32(pktout
, ssh
->term_height
);
9913 ssh2_pkt_adduint32(pktout
, 0);
9914 ssh2_pkt_adduint32(pktout
, 0);
9915 ssh2_pkt_send(ssh
, pktout
);
9923 * Return a list of the special codes that make sense in this
9926 static const struct telnet_special
*ssh_get_specials(void *handle
)
9928 static const struct telnet_special ssh1_ignore_special
[] = {
9929 {"IGNORE message", TS_NOP
}
9931 static const struct telnet_special ssh2_ignore_special
[] = {
9932 {"IGNORE message", TS_NOP
},
9934 static const struct telnet_special ssh2_rekey_special
[] = {
9935 {"Repeat key exchange", TS_REKEY
},
9937 static const struct telnet_special ssh2_session_specials
[] = {
9940 /* These are the signal names defined by RFC 4254.
9941 * They include all the ISO C signals, but are a subset of the POSIX
9942 * required signals. */
9943 {"SIGINT (Interrupt)", TS_SIGINT
},
9944 {"SIGTERM (Terminate)", TS_SIGTERM
},
9945 {"SIGKILL (Kill)", TS_SIGKILL
},
9946 {"SIGQUIT (Quit)", TS_SIGQUIT
},
9947 {"SIGHUP (Hangup)", TS_SIGHUP
},
9948 {"More signals", TS_SUBMENU
},
9949 {"SIGABRT", TS_SIGABRT
}, {"SIGALRM", TS_SIGALRM
},
9950 {"SIGFPE", TS_SIGFPE
}, {"SIGILL", TS_SIGILL
},
9951 {"SIGPIPE", TS_SIGPIPE
}, {"SIGSEGV", TS_SIGSEGV
},
9952 {"SIGUSR1", TS_SIGUSR1
}, {"SIGUSR2", TS_SIGUSR2
},
9955 static const struct telnet_special specials_end
[] = {
9958 /* XXX review this length for any changes: */
9959 static struct telnet_special ssh_specials
[lenof(ssh2_ignore_special
) +
9960 lenof(ssh2_rekey_special
) +
9961 lenof(ssh2_session_specials
) +
9962 lenof(specials_end
)];
9963 Ssh ssh
= (Ssh
) handle
;
9965 #define ADD_SPECIALS(name) \
9967 assert((i + lenof(name)) <= lenof(ssh_specials)); \
9968 memcpy(&ssh_specials[i], name, sizeof name); \
9972 if (ssh
->version
== 1) {
9973 /* Don't bother offering IGNORE if we've decided the remote
9974 * won't cope with it, since we wouldn't bother sending it if
9976 if (!(ssh
->remote_bugs
& BUG_CHOKES_ON_SSH1_IGNORE
))
9977 ADD_SPECIALS(ssh1_ignore_special
);
9978 } else if (ssh
->version
== 2) {
9979 if (!(ssh
->remote_bugs
& BUG_CHOKES_ON_SSH2_IGNORE
))
9980 ADD_SPECIALS(ssh2_ignore_special
);
9981 if (!(ssh
->remote_bugs
& BUG_SSH2_REKEY
))
9982 ADD_SPECIALS(ssh2_rekey_special
);
9984 ADD_SPECIALS(ssh2_session_specials
);
9985 } /* else we're not ready yet */
9988 ADD_SPECIALS(specials_end
);
9989 return ssh_specials
;
9997 * Send special codes. TS_EOF is useful for `plink', so you
9998 * can send an EOF and collect resulting output (e.g. `plink
10001 static void ssh_special(void *handle
, Telnet_Special code
)
10003 Ssh ssh
= (Ssh
) handle
;
10004 struct Packet
*pktout
;
10006 if (code
== TS_EOF
) {
10007 if (ssh
->state
!= SSH_STATE_SESSION
) {
10009 * Buffer the EOF in case we are pre-SESSION, so we can
10010 * send it as soon as we reach SESSION.
10012 if (code
== TS_EOF
)
10013 ssh
->eof_needed
= TRUE
;
10016 if (ssh
->version
== 1) {
10017 send_packet(ssh
, SSH1_CMSG_EOF
, PKT_END
);
10018 } else if (ssh
->mainchan
) {
10019 sshfwd_write_eof(ssh
->mainchan
);
10020 ssh
->send_ok
= 0; /* now stop trying to read from stdin */
10022 logevent("Sent EOF message");
10023 } else if (code
== TS_PING
|| code
== TS_NOP
) {
10024 if (ssh
->state
== SSH_STATE_CLOSED
10025 || ssh
->state
== SSH_STATE_PREPACKET
) return;
10026 if (ssh
->version
== 1) {
10027 if (!(ssh
->remote_bugs
& BUG_CHOKES_ON_SSH1_IGNORE
))
10028 send_packet(ssh
, SSH1_MSG_IGNORE
, PKT_STR
, "", PKT_END
);
10030 if (!(ssh
->remote_bugs
& BUG_CHOKES_ON_SSH2_IGNORE
)) {
10031 pktout
= ssh2_pkt_init(SSH2_MSG_IGNORE
);
10032 ssh2_pkt_addstring_start(pktout
);
10033 ssh2_pkt_send_noqueue(ssh
, pktout
);
10036 } else if (code
== TS_REKEY
) {
10037 if (!ssh
->kex_in_progress
&& ssh
->version
== 2) {
10038 do_ssh2_transport(ssh
, "at user request", -1, NULL
);
10040 } else if (code
== TS_BRK
) {
10041 if (ssh
->state
== SSH_STATE_CLOSED
10042 || ssh
->state
== SSH_STATE_PREPACKET
) return;
10043 if (ssh
->version
== 1) {
10044 logevent("Unable to send BREAK signal in SSH-1");
10045 } else if (ssh
->mainchan
) {
10046 pktout
= ssh2_chanreq_init(ssh
->mainchan
, "break", NULL
, NULL
);
10047 ssh2_pkt_adduint32(pktout
, 0); /* default break length */
10048 ssh2_pkt_send(ssh
, pktout
);
10051 /* Is is a POSIX signal? */
10052 char *signame
= NULL
;
10053 if (code
== TS_SIGABRT
) signame
= "ABRT";
10054 if (code
== TS_SIGALRM
) signame
= "ALRM";
10055 if (code
== TS_SIGFPE
) signame
= "FPE";
10056 if (code
== TS_SIGHUP
) signame
= "HUP";
10057 if (code
== TS_SIGILL
) signame
= "ILL";
10058 if (code
== TS_SIGINT
) signame
= "INT";
10059 if (code
== TS_SIGKILL
) signame
= "KILL";
10060 if (code
== TS_SIGPIPE
) signame
= "PIPE";
10061 if (code
== TS_SIGQUIT
) signame
= "QUIT";
10062 if (code
== TS_SIGSEGV
) signame
= "SEGV";
10063 if (code
== TS_SIGTERM
) signame
= "TERM";
10064 if (code
== TS_SIGUSR1
) signame
= "USR1";
10065 if (code
== TS_SIGUSR2
) signame
= "USR2";
10066 /* The SSH-2 protocol does in principle support arbitrary named
10067 * signals, including signame@domain, but we don't support those. */
10069 /* It's a signal. */
10070 if (ssh
->version
== 2 && ssh
->mainchan
) {
10071 pktout
= ssh2_chanreq_init(ssh
->mainchan
, "signal", NULL
, NULL
);
10072 ssh2_pkt_addstring(pktout
, signame
);
10073 ssh2_pkt_send(ssh
, pktout
);
10074 logeventf(ssh
, "Sent signal SIG%s", signame
);
10077 /* Never heard of it. Do nothing */
10082 void *new_sock_channel(void *handle
, Socket s
)
10084 Ssh ssh
= (Ssh
) handle
;
10085 struct ssh_channel
*c
;
10086 c
= snew(struct ssh_channel
);
10089 ssh2_channel_init(c
);
10090 c
->halfopen
= TRUE
;
10091 c
->type
= CHAN_SOCKDATA_DORMANT
;/* identify channel type */
10093 add234(ssh
->channels
, c
);
10098 * This is called when stdout/stderr (the entity to which
10099 * from_backend sends data) manages to clear some backlog.
10101 static void ssh_unthrottle(void *handle
, int bufsize
)
10103 Ssh ssh
= (Ssh
) handle
;
10106 if (ssh
->version
== 1) {
10107 if (ssh
->v1_stdout_throttling
&& bufsize
< SSH1_BUFFER_LIMIT
) {
10108 ssh
->v1_stdout_throttling
= 0;
10109 ssh_throttle_conn(ssh
, -1);
10112 if (ssh
->mainchan
) {
10113 ssh2_set_window(ssh
->mainchan
,
10114 bufsize
< ssh
->mainchan
->v
.v2
.locmaxwin ?
10115 ssh
->mainchan
->v
.v2
.locmaxwin
- bufsize
: 0);
10116 if (conf_get_int(ssh
->conf
, CONF_ssh_simple
))
10119 buflimit
= ssh
->mainchan
->v
.v2
.locmaxwin
;
10120 if (ssh
->mainchan
->throttling_conn
&& bufsize
<= buflimit
) {
10121 ssh
->mainchan
->throttling_conn
= 0;
10122 ssh_throttle_conn(ssh
, -1);
10128 * Now process any SSH connection data that was stashed in our
10129 * queue while we were frozen.
10131 ssh_process_queued_incoming_data(ssh
);
10134 void ssh_send_port_open(void *channel
, char *hostname
, int port
, char *org
)
10136 struct ssh_channel
*c
= (struct ssh_channel
*)channel
;
10138 struct Packet
*pktout
;
10140 logeventf(ssh
, "Opening forwarded connection to %s:%d", hostname
, port
);
10142 if (ssh
->version
== 1) {
10143 send_packet(ssh
, SSH1_MSG_PORT_OPEN
,
10144 PKT_INT
, c
->localid
,
10147 /* PKT_STR, <org:orgport>, */
10150 pktout
= ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN
);
10151 ssh2_pkt_addstring(pktout
, "direct-tcpip");
10152 ssh2_pkt_adduint32(pktout
, c
->localid
);
10153 ssh2_pkt_adduint32(pktout
, c
->v
.v2
.locwindow
);/* our window size */
10154 ssh2_pkt_adduint32(pktout
, OUR_V2_MAXPKT
); /* our max pkt size */
10155 ssh2_pkt_addstring(pktout
, hostname
);
10156 ssh2_pkt_adduint32(pktout
, port
);
10158 * We make up values for the originator data; partly it's
10159 * too much hassle to keep track, and partly I'm not
10160 * convinced the server should be told details like that
10161 * about my local network configuration.
10162 * The "originator IP address" is syntactically a numeric
10163 * IP address, and some servers (e.g., Tectia) get upset
10164 * if it doesn't match this syntax.
10166 ssh2_pkt_addstring(pktout
, "0.0.0.0");
10167 ssh2_pkt_adduint32(pktout
, 0);
10168 ssh2_pkt_send(ssh
, pktout
);
10172 static int ssh_connected(void *handle
)
10174 Ssh ssh
= (Ssh
) handle
;
10175 return ssh
->s
!= NULL
;
10178 static int ssh_sendok(void *handle
)
10180 Ssh ssh
= (Ssh
) handle
;
10181 return ssh
->send_ok
;
10184 static int ssh_ldisc(void *handle
, int option
)
10186 Ssh ssh
= (Ssh
) handle
;
10187 if (option
== LD_ECHO
)
10188 return ssh
->echoing
;
10189 if (option
== LD_EDIT
)
10190 return ssh
->editing
;
10194 static void ssh_provide_ldisc(void *handle
, void *ldisc
)
10196 Ssh ssh
= (Ssh
) handle
;
10197 ssh
->ldisc
= ldisc
;
10200 static void ssh_provide_logctx(void *handle
, void *logctx
)
10202 Ssh ssh
= (Ssh
) handle
;
10203 ssh
->logctx
= logctx
;
10206 static int ssh_return_exitcode(void *handle
)
10208 Ssh ssh
= (Ssh
) handle
;
10209 if (ssh
->s
!= NULL
)
10212 return (ssh
->exitcode
>= 0 ? ssh
->exitcode
: INT_MAX
);
10216 * cfg_info for SSH is the currently running version of the
10217 * protocol. (1 for 1; 2 for 2; 0 for not-decided-yet.)
10219 static int ssh_cfg_info(void *handle
)
10221 Ssh ssh
= (Ssh
) handle
;
10222 return ssh
->version
;
10226 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
10227 * that fails. This variable is the means by which scp.c can reach
10228 * into the SSH code and find out which one it got.
10230 extern int ssh_fallback_cmd(void *handle
)
10232 Ssh ssh
= (Ssh
) handle
;
10233 return ssh
->fallback_cmd
;
10236 Backend ssh_backend
= {
10246 ssh_return_exitcode
,
10250 ssh_provide_logctx
,