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, s) } *crLine = 0; sfree(s); return (z); }
443 #define crFinishFreeV(s) } *crLine = 0; 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 * little structure to keep track of outstanding WINDOW_ADJUSTs
600 * 2-3-4 tree storing channels.
603 Ssh ssh
; /* pointer back to main context */
604 unsigned remoteid
, localid
;
606 /* True if we opened this channel but server hasn't confirmed. */
609 * In SSH-1, this value contains four bits:
611 * 1 We have sent SSH1_MSG_CHANNEL_CLOSE.
612 * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
613 * 4 We have received SSH1_MSG_CHANNEL_CLOSE.
614 * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
616 * A channel is completely finished with when all four bits are set.
618 * In SSH-2, the four bits mean:
620 * 1 We have sent SSH2_MSG_CHANNEL_EOF.
621 * 2 We have sent SSH2_MSG_CHANNEL_CLOSE.
622 * 4 We have received SSH2_MSG_CHANNEL_EOF.
623 * 8 We have received SSH2_MSG_CHANNEL_CLOSE.
625 * A channel is completely finished with when we have both sent
626 * and received CLOSE.
628 * The symbolic constants below use the SSH-2 terminology, which
629 * is a bit confusing in SSH-1, but we have to use _something_.
631 #define CLOSES_SENT_EOF 1
632 #define CLOSES_SENT_CLOSE 2
633 #define CLOSES_RCVD_EOF 4
634 #define CLOSES_RCVD_CLOSE 8
638 * This flag indicates that an EOF is pending on the outgoing side
639 * of the channel: that is, wherever we're getting the data for
640 * this channel has sent us some data followed by EOF. We can't
641 * actually send the EOF until we've finished sending the data, so
642 * we set this flag instead to remind us to do so once our buffer
648 * True if this channel is causing the underlying connection to be
653 struct ssh2_data_channel
{
655 unsigned remwindow
, remmaxpkt
;
656 /* locwindow is signed so we can cope with excess data. */
657 int locwindow
, locmaxwin
;
659 * remlocwin is the amount of local window that we think
660 * the remote end had available to it after it sent the
661 * last data packet or window adjust ack.
665 * These store the list of channel requests that haven't
668 struct outstanding_channel_request
*chanreq_head
, *chanreq_tail
;
669 enum { THROTTLED
, UNTHROTTLING
, UNTHROTTLED
} throttle_state
;
673 struct ssh_agent_channel
{
674 unsigned char *message
;
675 unsigned char msglen
[4];
676 unsigned lensofar
, totallen
;
678 struct ssh_x11_channel
{
681 struct ssh_pfd_channel
{
688 * 2-3-4 tree storing remote->local port forwardings. SSH-1 and SSH-2
689 * use this structure in different ways, reflecting SSH-2's
690 * altogether saner approach to port forwarding.
692 * In SSH-1, you arrange a remote forwarding by sending the server
693 * the remote port number, and the local destination host:port.
694 * When a connection comes in, the server sends you back that
695 * host:port pair, and you connect to it. This is a ready-made
696 * security hole if you're not on the ball: a malicious server
697 * could send you back _any_ host:port pair, so if you trustingly
698 * connect to the address it gives you then you've just opened the
699 * entire inside of your corporate network just by connecting
700 * through it to a dodgy SSH server. Hence, we must store a list of
701 * host:port pairs we _are_ trying to forward to, and reject a
702 * connection request from the server if it's not in the list.
704 * In SSH-2, each side of the connection minds its own business and
705 * doesn't send unnecessary information to the other. You arrange a
706 * remote forwarding by sending the server just the remote port
707 * number. When a connection comes in, the server tells you which
708 * of its ports was connected to; and _you_ have to remember what
709 * local host:port pair went with that port number.
711 * Hence, in SSH-1 this structure is indexed by destination
712 * host:port pair, whereas in SSH-2 it is indexed by source port.
714 struct ssh_portfwd
; /* forward declaration */
716 struct ssh_rportfwd
{
717 unsigned sport
, dport
;
720 struct ssh_portfwd
*pfrec
;
722 #define free_rportfwd(pf) ( \
723 ((pf) ? (sfree((pf)->sportdesc)) : (void)0 ), sfree(pf) )
726 * Separately to the rportfwd tree (which is for looking up port
727 * open requests from the server), a tree of _these_ structures is
728 * used to keep track of all the currently open port forwardings,
729 * so that we can reconfigure in mid-session if the user requests
733 enum { DESTROY
, KEEP
, CREATE
} status
;
735 unsigned sport
, dport
;
738 struct ssh_rportfwd
*remote
;
742 #define free_portfwd(pf) ( \
743 ((pf) ? (sfree((pf)->saddr), sfree((pf)->daddr), \
744 sfree((pf)->sserv), sfree((pf)->dserv)) : (void)0 ), sfree(pf) )
747 long length
; /* length of `data' actually used */
748 long forcepad
; /* SSH-2: force padding to at least this length */
749 int type
; /* only used for incoming packets */
750 unsigned long sequence
; /* SSH-2 incoming sequence number */
751 unsigned char *data
; /* allocated storage */
752 unsigned char *body
; /* offset of payload within `data' */
753 long savedpos
; /* temporary index into `data' (for strings) */
754 long maxlen
; /* amount of storage allocated for `data' */
755 long encrypted_len
; /* for SSH-2 total-size counting */
758 * State associated with packet logging
762 struct logblank_t
*blanks
;
765 static void ssh1_protocol(Ssh ssh
, void *vin
, int inlen
,
766 struct Packet
*pktin
);
767 static void ssh2_protocol(Ssh ssh
, void *vin
, int inlen
,
768 struct Packet
*pktin
);
769 static void ssh1_protocol_setup(Ssh ssh
);
770 static void ssh2_protocol_setup(Ssh ssh
);
771 static void ssh_size(void *handle
, int width
, int height
);
772 static void ssh_special(void *handle
, Telnet_Special
);
773 static int ssh2_try_send(struct ssh_channel
*c
);
774 static void ssh2_add_channel_data(struct ssh_channel
*c
, char *buf
, int len
);
775 static void ssh_throttle_all(Ssh ssh
, int enable
, int bufsize
);
776 static void ssh2_set_window(struct ssh_channel
*c
, int newwin
);
777 static int ssh_sendbuffer(void *handle
);
778 static int ssh_do_close(Ssh ssh
, int notify_exit
);
779 static unsigned long ssh_pkt_getuint32(struct Packet
*pkt
);
780 static int ssh2_pkt_getbool(struct Packet
*pkt
);
781 static void ssh_pkt_getstring(struct Packet
*pkt
, char **p
, int *length
);
782 static void ssh2_timer(void *ctx
, long now
);
783 static int do_ssh2_transport(Ssh ssh
, void *vin
, int inlen
,
784 struct Packet
*pktin
);
785 static void ssh2_msg_unexpected(Ssh ssh
, struct Packet
*pktin
);
787 struct rdpkt1_state_tag
{
788 long len
, pad
, biglen
, to_read
;
789 unsigned long realcrc
, gotcrc
;
793 struct Packet
*pktin
;
796 struct rdpkt2_state_tag
{
797 long len
, pad
, payload
, packetlen
, maclen
;
800 unsigned long incoming_sequence
;
801 struct Packet
*pktin
;
804 struct queued_handler
;
805 struct queued_handler
{
807 chandler_fn_t handler
;
809 struct queued_handler
*next
;
813 const struct plug_function_table
*fn
;
814 /* the above field _must_ be first in the structure */
824 unsigned char session_key
[32];
826 int v1_remote_protoflags
;
827 int v1_local_protoflags
;
828 int agentfwd_enabled
;
831 const struct ssh_cipher
*cipher
;
834 const struct ssh2_cipher
*cscipher
, *sccipher
;
835 void *cs_cipher_ctx
, *sc_cipher_ctx
;
836 const struct ssh_mac
*csmac
, *scmac
;
837 void *cs_mac_ctx
, *sc_mac_ctx
;
838 const struct ssh_compress
*cscomp
, *sccomp
;
839 void *cs_comp_ctx
, *sc_comp_ctx
;
840 const struct ssh_kex
*kex
;
841 const struct ssh_signkey
*hostkey
;
842 unsigned char v2_session_id
[SSH2_KEX_MAX_HASH_LEN
];
843 int v2_session_id_len
;
849 int echoing
, editing
;
853 int ospeed
, ispeed
; /* temporaries */
854 int term_width
, term_height
;
856 tree234
*channels
; /* indexed by local id */
857 struct ssh_channel
*mainchan
; /* primary session channel */
858 int ncmode
; /* is primary channel direct-tcpip? */
863 tree234
*rportfwds
, *portfwds
;
867 SSH_STATE_BEFORE_SIZE
,
873 int size_needed
, eof_needed
;
874 int sent_console_eof
;
875 int got_pty
; /* affects EOF behaviour on main channel */
877 struct Packet
**queue
;
878 int queuelen
, queuesize
;
880 unsigned char *deferred_send_data
;
881 int deferred_len
, deferred_size
;
884 * Gross hack: pscp will try to start SFTP but fall back to
885 * scp1 if that fails. This variable is the means by which
886 * scp.c can reach into the SSH code and find out which one it
891 bufchain banner
; /* accumulates banners during do_ssh2_authconn */
896 struct X11Display
*x11disp
;
899 int conn_throttle_count
;
902 int v1_stdout_throttling
;
903 unsigned long v2_outgoing_sequence
;
905 int ssh1_rdpkt_crstate
;
906 int ssh2_rdpkt_crstate
;
907 int ssh_gotdata_crstate
;
908 int do_ssh1_connection_crstate
;
910 void *do_ssh_init_state
;
911 void *do_ssh1_login_state
;
912 void *do_ssh2_transport_state
;
913 void *do_ssh2_authconn_state
;
915 struct rdpkt1_state_tag rdpkt1_state
;
916 struct rdpkt2_state_tag rdpkt2_state
;
918 /* SSH-1 and SSH-2 use this for different things, but both use it */
919 int protocol_initial_phase_done
;
921 void (*protocol
) (Ssh ssh
, void *vin
, int inlen
,
923 struct Packet
*(*s_rdpkt
) (Ssh ssh
, unsigned char **data
, int *datalen
);
926 * We maintain our own copy of a Conf structure here. That way,
927 * when we're passed a new one for reconfiguration, we can check
928 * the differences and potentially reconfigure port forwardings
929 * etc in mid-session.
934 * Values cached out of conf so as to avoid the tree234 lookup
935 * cost every time they're used.
940 * Dynamically allocated username string created during SSH
941 * login. Stored in here rather than in the coroutine state so
942 * that it'll be reliably freed if we shut down the SSH session
943 * at some unexpected moment.
948 * Used to transfer data back from async callbacks.
950 void *agent_response
;
951 int agent_response_len
;
955 * The SSH connection can be set as `frozen', meaning we are
956 * not currently accepting incoming data from the network. This
957 * is slightly more serious than setting the _socket_ as
958 * frozen, because we may already have had data passed to us
959 * from the network which we need to delay processing until
960 * after the freeze is lifted, so we also need a bufchain to
964 bufchain queued_incoming_data
;
967 * Dispatch table for packet types that we may have to deal
970 handler_fn_t packet_dispatch
[256];
973 * Queues of one-off handler functions for success/failure
974 * indications from a request.
976 struct queued_handler
*qhead
, *qtail
;
977 handler_fn_t q_saved_handler1
, q_saved_handler2
;
980 * This module deals with sending keepalives.
985 * Track incoming and outgoing data sizes and time, for
988 unsigned long incoming_data_size
, outgoing_data_size
, deferred_data_size
;
989 unsigned long max_data_size
;
991 long next_rekey
, last_rekey
;
992 char *deferred_rekey_reason
; /* points to STATIC string; don't free */
995 * Fully qualified host name, which we need if doing GSSAPI.
1001 * GSSAPI libraries for this session.
1003 struct ssh_gss_liblist
*gsslibs
;
1007 #define logevent(s) logevent(ssh->frontend, s)
1009 /* logevent, only printf-formatted. */
1010 static void logeventf(Ssh ssh
, const char *fmt
, ...)
1016 buf
= dupvprintf(fmt
, ap
);
1022 #define bombout(msg) \
1024 char *text = dupprintf msg; \
1025 ssh_do_close(ssh, FALSE); \
1027 connection_fatal(ssh->frontend, "%s", text); \
1031 /* Functions to leave bits out of the SSH packet log file. */
1033 static void dont_log_password(Ssh ssh
, struct Packet
*pkt
, int blanktype
)
1035 if (conf_get_int(ssh
->conf
, CONF_logomitpass
))
1036 pkt
->logmode
= blanktype
;
1039 static void dont_log_data(Ssh ssh
, struct Packet
*pkt
, int blanktype
)
1041 if (ssh
->logomitdata
)
1042 pkt
->logmode
= blanktype
;
1045 static void end_log_omission(Ssh ssh
, struct Packet
*pkt
)
1047 pkt
->logmode
= PKTLOG_EMIT
;
1050 /* Helper function for common bits of parsing ttymodes. */
1051 static void parse_ttymodes(Ssh ssh
,
1052 void (*do_mode
)(void *data
, char *mode
, char *val
),
1057 for (val
= conf_get_str_strs(ssh
->conf
, CONF_ttymodes
, NULL
, &key
);
1059 val
= conf_get_str_strs(ssh
->conf
, CONF_ttymodes
, key
, &key
)) {
1061 * val[0] is either 'V', indicating that an explicit value
1062 * follows it, or 'A' indicating that we should pass the
1063 * value through from the local environment via get_ttymode.
1066 val
= get_ttymode(ssh
->frontend
, key
);
1068 val
++; /* skip the 'V' */
1070 do_mode(data
, key
, val
);
1074 static int ssh_channelcmp(void *av
, void *bv
)
1076 struct ssh_channel
*a
= (struct ssh_channel
*) av
;
1077 struct ssh_channel
*b
= (struct ssh_channel
*) bv
;
1078 if (a
->localid
< b
->localid
)
1080 if (a
->localid
> b
->localid
)
1084 static int ssh_channelfind(void *av
, void *bv
)
1086 unsigned *a
= (unsigned *) av
;
1087 struct ssh_channel
*b
= (struct ssh_channel
*) bv
;
1088 if (*a
< b
->localid
)
1090 if (*a
> b
->localid
)
1095 static int ssh_rportcmp_ssh1(void *av
, void *bv
)
1097 struct ssh_rportfwd
*a
= (struct ssh_rportfwd
*) av
;
1098 struct ssh_rportfwd
*b
= (struct ssh_rportfwd
*) bv
;
1100 if ( (i
= strcmp(a
->dhost
, b
->dhost
)) != 0)
1101 return i
< 0 ?
-1 : +1;
1102 if (a
->dport
> b
->dport
)
1104 if (a
->dport
< b
->dport
)
1109 static int ssh_rportcmp_ssh2(void *av
, void *bv
)
1111 struct ssh_rportfwd
*a
= (struct ssh_rportfwd
*) av
;
1112 struct ssh_rportfwd
*b
= (struct ssh_rportfwd
*) bv
;
1114 if (a
->sport
> b
->sport
)
1116 if (a
->sport
< b
->sport
)
1122 * Special form of strcmp which can cope with NULL inputs. NULL is
1123 * defined to sort before even the empty string.
1125 static int nullstrcmp(const char *a
, const char *b
)
1127 if (a
== NULL
&& b
== NULL
)
1133 return strcmp(a
, b
);
1136 static int ssh_portcmp(void *av
, void *bv
)
1138 struct ssh_portfwd
*a
= (struct ssh_portfwd
*) av
;
1139 struct ssh_portfwd
*b
= (struct ssh_portfwd
*) bv
;
1141 if (a
->type
> b
->type
)
1143 if (a
->type
< b
->type
)
1145 if (a
->addressfamily
> b
->addressfamily
)
1147 if (a
->addressfamily
< b
->addressfamily
)
1149 if ( (i
= nullstrcmp(a
->saddr
, b
->saddr
)) != 0)
1150 return i
< 0 ?
-1 : +1;
1151 if (a
->sport
> b
->sport
)
1153 if (a
->sport
< b
->sport
)
1155 if (a
->type
!= 'D') {
1156 if ( (i
= nullstrcmp(a
->daddr
, b
->daddr
)) != 0)
1157 return i
< 0 ?
-1 : +1;
1158 if (a
->dport
> b
->dport
)
1160 if (a
->dport
< b
->dport
)
1166 static int alloc_channel_id(Ssh ssh
)
1168 const unsigned CHANNEL_NUMBER_OFFSET
= 256;
1169 unsigned low
, high
, mid
;
1171 struct ssh_channel
*c
;
1174 * First-fit allocation of channel numbers: always pick the
1175 * lowest unused one. To do this, binary-search using the
1176 * counted B-tree to find the largest channel ID which is in a
1177 * contiguous sequence from the beginning. (Precisely
1178 * everything in that sequence must have ID equal to its tree
1179 * index plus CHANNEL_NUMBER_OFFSET.)
1181 tsize
= count234(ssh
->channels
);
1185 while (high
- low
> 1) {
1186 mid
= (high
+ low
) / 2;
1187 c
= index234(ssh
->channels
, mid
);
1188 if (c
->localid
== mid
+ CHANNEL_NUMBER_OFFSET
)
1189 low
= mid
; /* this one is fine */
1191 high
= mid
; /* this one is past it */
1194 * Now low points to either -1, or the tree index of the
1195 * largest ID in the initial sequence.
1198 unsigned i
= low
+ 1 + CHANNEL_NUMBER_OFFSET
;
1199 assert(NULL
== find234(ssh
->channels
, &i
, ssh_channelfind
));
1201 return low
+ 1 + CHANNEL_NUMBER_OFFSET
;
1204 static void c_write_stderr(int trusted
, const char *buf
, int len
)
1207 for (i
= 0; i
< len
; i
++)
1208 if (buf
[i
] != '\r' && (trusted
|| buf
[i
] == '\n' || (buf
[i
] & 0x60)))
1209 fputc(buf
[i
], stderr
);
1212 static void c_write(Ssh ssh
, const char *buf
, int len
)
1214 if (flags
& FLAG_STDERR
)
1215 c_write_stderr(1, buf
, len
);
1217 from_backend(ssh
->frontend
, 1, buf
, len
);
1220 static void c_write_untrusted(Ssh ssh
, const char *buf
, int len
)
1222 if (flags
& FLAG_STDERR
)
1223 c_write_stderr(0, buf
, len
);
1225 from_backend_untrusted(ssh
->frontend
, buf
, len
);
1228 static void c_write_str(Ssh ssh
, const char *buf
)
1230 c_write(ssh
, buf
, strlen(buf
));
1233 static void ssh_free_packet(struct Packet
*pkt
)
1238 static struct Packet
*ssh_new_packet(void)
1240 struct Packet
*pkt
= snew(struct Packet
);
1242 pkt
->body
= pkt
->data
= NULL
;
1244 pkt
->logmode
= PKTLOG_EMIT
;
1252 * Collect incoming data in the incoming packet buffer.
1253 * Decipher and verify the packet when it is completely read.
1254 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
1255 * Update the *data and *datalen variables.
1256 * Return a Packet structure when a packet is completed.
1258 static struct Packet
*ssh1_rdpkt(Ssh ssh
, unsigned char **data
, int *datalen
)
1260 struct rdpkt1_state_tag
*st
= &ssh
->rdpkt1_state
;
1262 crBegin(ssh
->ssh1_rdpkt_crstate
);
1264 st
->pktin
= ssh_new_packet();
1266 st
->pktin
->type
= 0;
1267 st
->pktin
->length
= 0;
1269 for (st
->i
= st
->len
= 0; st
->i
< 4; st
->i
++) {
1270 while ((*datalen
) == 0)
1272 st
->len
= (st
->len
<< 8) + **data
;
1273 (*data
)++, (*datalen
)--;
1276 st
->pad
= 8 - (st
->len
% 8);
1277 st
->biglen
= st
->len
+ st
->pad
;
1278 st
->pktin
->length
= st
->len
- 5;
1280 if (st
->biglen
< 0) {
1281 bombout(("Extremely large packet length from server suggests"
1282 " data stream corruption"));
1283 ssh_free_packet(st
->pktin
);
1287 st
->pktin
->maxlen
= st
->biglen
;
1288 st
->pktin
->data
= snewn(st
->biglen
+ APIEXTRA
, unsigned char);
1290 st
->to_read
= st
->biglen
;
1291 st
->p
= st
->pktin
->data
;
1292 while (st
->to_read
> 0) {
1293 st
->chunk
= st
->to_read
;
1294 while ((*datalen
) == 0)
1296 if (st
->chunk
> (*datalen
))
1297 st
->chunk
= (*datalen
);
1298 memcpy(st
->p
, *data
, st
->chunk
);
1300 *datalen
-= st
->chunk
;
1302 st
->to_read
-= st
->chunk
;
1305 if (ssh
->cipher
&& detect_attack(ssh
->crcda_ctx
, st
->pktin
->data
,
1306 st
->biglen
, NULL
)) {
1307 bombout(("Network attack (CRC compensation) detected!"));
1308 ssh_free_packet(st
->pktin
);
1313 ssh
->cipher
->decrypt(ssh
->v1_cipher_ctx
, st
->pktin
->data
, st
->biglen
);
1315 st
->realcrc
= crc32_compute(st
->pktin
->data
, st
->biglen
- 4);
1316 st
->gotcrc
= GET_32BIT(st
->pktin
->data
+ st
->biglen
- 4);
1317 if (st
->gotcrc
!= st
->realcrc
) {
1318 bombout(("Incorrect CRC received on packet"));
1319 ssh_free_packet(st
->pktin
);
1323 st
->pktin
->body
= st
->pktin
->data
+ st
->pad
+ 1;
1324 st
->pktin
->savedpos
= 0;
1326 if (ssh
->v1_compressing
) {
1327 unsigned char *decompblk
;
1329 if (!zlib_decompress_block(ssh
->sc_comp_ctx
,
1330 st
->pktin
->body
- 1, st
->pktin
->length
+ 1,
1331 &decompblk
, &decomplen
)) {
1332 bombout(("Zlib decompression encountered invalid data"));
1333 ssh_free_packet(st
->pktin
);
1337 if (st
->pktin
->maxlen
< st
->pad
+ decomplen
) {
1338 st
->pktin
->maxlen
= st
->pad
+ decomplen
;
1339 st
->pktin
->data
= sresize(st
->pktin
->data
,
1340 st
->pktin
->maxlen
+ APIEXTRA
,
1342 st
->pktin
->body
= st
->pktin
->data
+ st
->pad
+ 1;
1345 memcpy(st
->pktin
->body
- 1, decompblk
, decomplen
);
1347 st
->pktin
->length
= decomplen
- 1;
1350 st
->pktin
->type
= st
->pktin
->body
[-1];
1353 * Log incoming packet, possibly omitting sensitive fields.
1357 struct logblank_t blank
;
1358 if (ssh
->logomitdata
) {
1359 int do_blank
= FALSE
, blank_prefix
= 0;
1360 /* "Session data" packets - omit the data field */
1361 if ((st
->pktin
->type
== SSH1_SMSG_STDOUT_DATA
) ||
1362 (st
->pktin
->type
== SSH1_SMSG_STDERR_DATA
)) {
1363 do_blank
= TRUE
; blank_prefix
= 4;
1364 } else if (st
->pktin
->type
== SSH1_MSG_CHANNEL_DATA
) {
1365 do_blank
= TRUE
; blank_prefix
= 8;
1368 blank
.offset
= blank_prefix
;
1369 blank
.len
= st
->pktin
->length
;
1370 blank
.type
= PKTLOG_OMIT
;
1374 log_packet(ssh
->logctx
,
1375 PKT_INCOMING
, st
->pktin
->type
,
1376 ssh1_pkt_type(st
->pktin
->type
),
1377 st
->pktin
->body
, st
->pktin
->length
,
1378 nblanks
, &blank
, NULL
);
1381 crFinish(st
->pktin
);
1384 static struct Packet
*ssh2_rdpkt(Ssh ssh
, unsigned char **data
, int *datalen
)
1386 struct rdpkt2_state_tag
*st
= &ssh
->rdpkt2_state
;
1388 crBegin(ssh
->ssh2_rdpkt_crstate
);
1390 st
->pktin
= ssh_new_packet();
1392 st
->pktin
->type
= 0;
1393 st
->pktin
->length
= 0;
1395 st
->cipherblk
= ssh
->sccipher
->blksize
;
1398 if (st
->cipherblk
< 8)
1400 st
->maclen
= ssh
->scmac ? ssh
->scmac
->len
: 0;
1402 if (ssh
->sccipher
&& (ssh
->sccipher
->flags
& SSH_CIPHER_IS_CBC
) &&
1405 * When dealing with a CBC-mode cipher, we want to avoid the
1406 * possibility of an attacker's tweaking the ciphertext stream
1407 * so as to cause us to feed the same block to the block
1408 * cipher more than once and thus leak information
1409 * (VU#958563). The way we do this is not to take any
1410 * decisions on the basis of anything we've decrypted until
1411 * we've verified it with a MAC. That includes the packet
1412 * length, so we just read data and check the MAC repeatedly,
1413 * and when the MAC passes, see if the length we've got is
1417 /* May as well allocate the whole lot now. */
1418 st
->pktin
->data
= snewn(OUR_V2_PACKETLIMIT
+ st
->maclen
+ APIEXTRA
,
1421 /* Read an amount corresponding to the MAC. */
1422 for (st
->i
= 0; st
->i
< st
->maclen
; st
->i
++) {
1423 while ((*datalen
) == 0)
1425 st
->pktin
->data
[st
->i
] = *(*data
)++;
1431 unsigned char seq
[4];
1432 ssh
->scmac
->start(ssh
->sc_mac_ctx
);
1433 PUT_32BIT(seq
, st
->incoming_sequence
);
1434 ssh
->scmac
->bytes(ssh
->sc_mac_ctx
, seq
, 4);
1437 for (;;) { /* Once around this loop per cipher block. */
1438 /* Read another cipher-block's worth, and tack it onto the end. */
1439 for (st
->i
= 0; st
->i
< st
->cipherblk
; st
->i
++) {
1440 while ((*datalen
) == 0)
1442 st
->pktin
->data
[st
->packetlen
+st
->maclen
+st
->i
] = *(*data
)++;
1445 /* Decrypt one more block (a little further back in the stream). */
1446 ssh
->sccipher
->decrypt(ssh
->sc_cipher_ctx
,
1447 st
->pktin
->data
+ st
->packetlen
,
1449 /* Feed that block to the MAC. */
1450 ssh
->scmac
->bytes(ssh
->sc_mac_ctx
,
1451 st
->pktin
->data
+ st
->packetlen
, st
->cipherblk
);
1452 st
->packetlen
+= st
->cipherblk
;
1453 /* See if that gives us a valid packet. */
1454 if (ssh
->scmac
->verresult(ssh
->sc_mac_ctx
,
1455 st
->pktin
->data
+ st
->packetlen
) &&
1456 (st
->len
= GET_32BIT(st
->pktin
->data
)) + 4 == st
->packetlen
)
1458 if (st
->packetlen
>= OUR_V2_PACKETLIMIT
) {
1459 bombout(("No valid incoming packet found"));
1460 ssh_free_packet(st
->pktin
);
1464 st
->pktin
->maxlen
= st
->packetlen
+ st
->maclen
;
1465 st
->pktin
->data
= sresize(st
->pktin
->data
,
1466 st
->pktin
->maxlen
+ APIEXTRA
,
1469 st
->pktin
->data
= snewn(st
->cipherblk
+ APIEXTRA
, unsigned char);
1472 * Acquire and decrypt the first block of the packet. This will
1473 * contain the length and padding details.
1475 for (st
->i
= st
->len
= 0; st
->i
< st
->cipherblk
; st
->i
++) {
1476 while ((*datalen
) == 0)
1478 st
->pktin
->data
[st
->i
] = *(*data
)++;
1483 ssh
->sccipher
->decrypt(ssh
->sc_cipher_ctx
,
1484 st
->pktin
->data
, st
->cipherblk
);
1487 * Now get the length figure.
1489 st
->len
= GET_32BIT(st
->pktin
->data
);
1492 * _Completely_ silly lengths should be stomped on before they
1493 * do us any more damage.
1495 if (st
->len
< 0 || st
->len
> OUR_V2_PACKETLIMIT
||
1496 (st
->len
+ 4) % st
->cipherblk
!= 0) {
1497 bombout(("Incoming packet was garbled on decryption"));
1498 ssh_free_packet(st
->pktin
);
1503 * So now we can work out the total packet length.
1505 st
->packetlen
= st
->len
+ 4;
1508 * Allocate memory for the rest of the packet.
1510 st
->pktin
->maxlen
= st
->packetlen
+ st
->maclen
;
1511 st
->pktin
->data
= sresize(st
->pktin
->data
,
1512 st
->pktin
->maxlen
+ APIEXTRA
,
1516 * Read and decrypt the remainder of the packet.
1518 for (st
->i
= st
->cipherblk
; st
->i
< st
->packetlen
+ st
->maclen
;
1520 while ((*datalen
) == 0)
1522 st
->pktin
->data
[st
->i
] = *(*data
)++;
1525 /* Decrypt everything _except_ the MAC. */
1527 ssh
->sccipher
->decrypt(ssh
->sc_cipher_ctx
,
1528 st
->pktin
->data
+ st
->cipherblk
,
1529 st
->packetlen
- st
->cipherblk
);
1535 && !ssh
->scmac
->verify(ssh
->sc_mac_ctx
, st
->pktin
->data
,
1536 st
->len
+ 4, st
->incoming_sequence
)) {
1537 bombout(("Incorrect MAC received on packet"));
1538 ssh_free_packet(st
->pktin
);
1542 /* Get and sanity-check the amount of random padding. */
1543 st
->pad
= st
->pktin
->data
[4];
1544 if (st
->pad
< 4 || st
->len
- st
->pad
< 1) {
1545 bombout(("Invalid padding length on received packet"));
1546 ssh_free_packet(st
->pktin
);
1550 * This enables us to deduce the payload length.
1552 st
->payload
= st
->len
- st
->pad
- 1;
1554 st
->pktin
->length
= st
->payload
+ 5;
1555 st
->pktin
->encrypted_len
= st
->packetlen
;
1557 st
->pktin
->sequence
= st
->incoming_sequence
++;
1560 * Decompress packet payload.
1563 unsigned char *newpayload
;
1566 ssh
->sccomp
->decompress(ssh
->sc_comp_ctx
,
1567 st
->pktin
->data
+ 5, st
->pktin
->length
- 5,
1568 &newpayload
, &newlen
)) {
1569 if (st
->pktin
->maxlen
< newlen
+ 5) {
1570 st
->pktin
->maxlen
= newlen
+ 5;
1571 st
->pktin
->data
= sresize(st
->pktin
->data
,
1572 st
->pktin
->maxlen
+ APIEXTRA
,
1575 st
->pktin
->length
= 5 + newlen
;
1576 memcpy(st
->pktin
->data
+ 5, newpayload
, newlen
);
1581 st
->pktin
->savedpos
= 6;
1582 st
->pktin
->body
= st
->pktin
->data
;
1583 st
->pktin
->type
= st
->pktin
->data
[5];
1586 * Log incoming packet, possibly omitting sensitive fields.
1590 struct logblank_t blank
;
1591 if (ssh
->logomitdata
) {
1592 int do_blank
= FALSE
, blank_prefix
= 0;
1593 /* "Session data" packets - omit the data field */
1594 if (st
->pktin
->type
== SSH2_MSG_CHANNEL_DATA
) {
1595 do_blank
= TRUE
; blank_prefix
= 8;
1596 } else if (st
->pktin
->type
== SSH2_MSG_CHANNEL_EXTENDED_DATA
) {
1597 do_blank
= TRUE
; blank_prefix
= 12;
1600 blank
.offset
= blank_prefix
;
1601 blank
.len
= (st
->pktin
->length
-6) - blank_prefix
;
1602 blank
.type
= PKTLOG_OMIT
;
1606 log_packet(ssh
->logctx
, PKT_INCOMING
, st
->pktin
->type
,
1607 ssh2_pkt_type(ssh
->pkt_kctx
, ssh
->pkt_actx
,
1609 st
->pktin
->data
+6, st
->pktin
->length
-6,
1610 nblanks
, &blank
, &st
->pktin
->sequence
);
1613 crFinish(st
->pktin
);
1616 static int s_wrpkt_prepare(Ssh ssh
, struct Packet
*pkt
, int *offset_p
)
1618 int pad
, biglen
, i
, pktoffs
;
1622 * XXX various versions of SC (including 8.8.4) screw up the
1623 * register allocation in this function and use the same register
1624 * (D6) for len and as a temporary, with predictable results. The
1625 * following sledgehammer prevents this.
1632 log_packet(ssh
->logctx
, PKT_OUTGOING
, pkt
->data
[12],
1633 ssh1_pkt_type(pkt
->data
[12]),
1634 pkt
->body
, pkt
->length
- (pkt
->body
- pkt
->data
),
1635 pkt
->nblanks
, pkt
->blanks
, NULL
);
1636 sfree(pkt
->blanks
); pkt
->blanks
= NULL
;
1639 if (ssh
->v1_compressing
) {
1640 unsigned char *compblk
;
1642 zlib_compress_block(ssh
->cs_comp_ctx
,
1643 pkt
->data
+ 12, pkt
->length
- 12,
1644 &compblk
, &complen
);
1645 ssh_pkt_ensure(pkt
, complen
+ 2); /* just in case it's got bigger */
1646 memcpy(pkt
->data
+ 12, compblk
, complen
);
1648 pkt
->length
= complen
+ 12;
1651 ssh_pkt_ensure(pkt
, pkt
->length
+ 4); /* space for CRC */
1653 len
= pkt
->length
- 4 - 8; /* len(type+data+CRC) */
1654 pad
= 8 - (len
% 8);
1656 biglen
= len
+ pad
; /* len(padding+type+data+CRC) */
1658 for (i
= pktoffs
; i
< 4+8; i
++)
1659 pkt
->data
[i
] = random_byte();
1660 crc
= crc32_compute(pkt
->data
+ pktoffs
+ 4, biglen
- 4); /* all ex len */
1661 PUT_32BIT(pkt
->data
+ pktoffs
+ 4 + biglen
- 4, crc
);
1662 PUT_32BIT(pkt
->data
+ pktoffs
, len
);
1665 ssh
->cipher
->encrypt(ssh
->v1_cipher_ctx
,
1666 pkt
->data
+ pktoffs
+ 4, biglen
);
1668 if (offset_p
) *offset_p
= pktoffs
;
1669 return biglen
+ 4; /* len(length+padding+type+data+CRC) */
1672 static int s_write(Ssh ssh
, void *data
, int len
)
1675 log_packet(ssh
->logctx
, PKT_OUTGOING
, -1, NULL
, data
, len
,
1677 return sk_write(ssh
->s
, (char *)data
, len
);
1680 static void s_wrpkt(Ssh ssh
, struct Packet
*pkt
)
1682 int len
, backlog
, offset
;
1683 len
= s_wrpkt_prepare(ssh
, pkt
, &offset
);
1684 backlog
= s_write(ssh
, pkt
->data
+ offset
, len
);
1685 if (backlog
> SSH_MAX_BACKLOG
)
1686 ssh_throttle_all(ssh
, 1, backlog
);
1687 ssh_free_packet(pkt
);
1690 static void s_wrpkt_defer(Ssh ssh
, struct Packet
*pkt
)
1693 len
= s_wrpkt_prepare(ssh
, pkt
, &offset
);
1694 if (ssh
->deferred_len
+ len
> ssh
->deferred_size
) {
1695 ssh
->deferred_size
= ssh
->deferred_len
+ len
+ 128;
1696 ssh
->deferred_send_data
= sresize(ssh
->deferred_send_data
,
1700 memcpy(ssh
->deferred_send_data
+ ssh
->deferred_len
,
1701 pkt
->data
+ offset
, len
);
1702 ssh
->deferred_len
+= len
;
1703 ssh_free_packet(pkt
);
1707 * Construct a SSH-1 packet with the specified contents.
1708 * (This all-at-once interface used to be the only one, but now SSH-1
1709 * packets can also be constructed incrementally.)
1711 static struct Packet
*construct_packet(Ssh ssh
, int pkttype
, va_list ap
)
1717 pkt
= ssh1_pkt_init(pkttype
);
1719 while ((argtype
= va_arg(ap
, int)) != PKT_END
) {
1720 unsigned char *argp
, argchar
;
1722 unsigned long argint
;
1725 /* Actual fields in the packet */
1727 argint
= va_arg(ap
, int);
1728 ssh_pkt_adduint32(pkt
, argint
);
1731 argchar
= (unsigned char) va_arg(ap
, int);
1732 ssh_pkt_addbyte(pkt
, argchar
);
1735 argp
= va_arg(ap
, unsigned char *);
1736 arglen
= va_arg(ap
, int);
1737 ssh_pkt_adddata(pkt
, argp
, arglen
);
1740 sargp
= va_arg(ap
, char *);
1741 ssh_pkt_addstring(pkt
, sargp
);
1744 bn
= va_arg(ap
, Bignum
);
1745 ssh1_pkt_addmp(pkt
, bn
);
1747 /* Tokens for modifications to packet logging */
1749 dont_log_password(ssh
, pkt
, PKTLOG_BLANK
);
1752 dont_log_data(ssh
, pkt
, PKTLOG_OMIT
);
1755 end_log_omission(ssh
, pkt
);
1763 static void send_packet(Ssh ssh
, int pkttype
, ...)
1767 va_start(ap
, pkttype
);
1768 pkt
= construct_packet(ssh
, pkttype
, ap
);
1773 static void defer_packet(Ssh ssh
, int pkttype
, ...)
1777 va_start(ap
, pkttype
);
1778 pkt
= construct_packet(ssh
, pkttype
, ap
);
1780 s_wrpkt_defer(ssh
, pkt
);
1783 static int ssh_versioncmp(char *a
, char *b
)
1786 unsigned long av
, bv
;
1788 av
= strtoul(a
, &ae
, 10);
1789 bv
= strtoul(b
, &be
, 10);
1791 return (av
< bv ?
-1 : +1);
1796 av
= strtoul(ae
, &ae
, 10);
1797 bv
= strtoul(be
, &be
, 10);
1799 return (av
< bv ?
-1 : +1);
1804 * Utility routines for putting an SSH-protocol `string' and
1805 * `uint32' into a hash state.
1807 static void hash_string(const struct ssh_hash
*h
, void *s
, void *str
, int len
)
1809 unsigned char lenblk
[4];
1810 PUT_32BIT(lenblk
, len
);
1811 h
->bytes(s
, lenblk
, 4);
1812 h
->bytes(s
, str
, len
);
1815 static void hash_uint32(const struct ssh_hash
*h
, void *s
, unsigned i
)
1817 unsigned char intblk
[4];
1818 PUT_32BIT(intblk
, i
);
1819 h
->bytes(s
, intblk
, 4);
1823 * Packet construction functions. Mostly shared between SSH-1 and SSH-2.
1825 static void ssh_pkt_ensure(struct Packet
*pkt
, int length
)
1827 if (pkt
->maxlen
< length
) {
1828 unsigned char *body
= pkt
->body
;
1829 int offset
= body ? body
- pkt
->data
: 0;
1830 pkt
->maxlen
= length
+ 256;
1831 pkt
->data
= sresize(pkt
->data
, pkt
->maxlen
+ APIEXTRA
, unsigned char);
1832 if (body
) pkt
->body
= pkt
->data
+ offset
;
1835 static void ssh_pkt_adddata(struct Packet
*pkt
, void *data
, int len
)
1837 if (pkt
->logmode
!= PKTLOG_EMIT
) {
1839 pkt
->blanks
= sresize(pkt
->blanks
, pkt
->nblanks
, struct logblank_t
);
1841 pkt
->blanks
[pkt
->nblanks
-1].offset
= pkt
->length
-
1842 (pkt
->body
- pkt
->data
);
1843 pkt
->blanks
[pkt
->nblanks
-1].len
= len
;
1844 pkt
->blanks
[pkt
->nblanks
-1].type
= pkt
->logmode
;
1847 ssh_pkt_ensure(pkt
, pkt
->length
);
1848 memcpy(pkt
->data
+ pkt
->length
- len
, data
, len
);
1850 static void ssh_pkt_addbyte(struct Packet
*pkt
, unsigned char byte
)
1852 ssh_pkt_adddata(pkt
, &byte
, 1);
1854 static void ssh2_pkt_addbool(struct Packet
*pkt
, unsigned char value
)
1856 ssh_pkt_adddata(pkt
, &value
, 1);
1858 static void ssh_pkt_adduint32(struct Packet
*pkt
, unsigned long value
)
1861 PUT_32BIT(x
, value
);
1862 ssh_pkt_adddata(pkt
, x
, 4);
1864 static void ssh_pkt_addstring_start(struct Packet
*pkt
)
1866 ssh_pkt_adduint32(pkt
, 0);
1867 pkt
->savedpos
= pkt
->length
;
1869 static void ssh_pkt_addstring_str(struct Packet
*pkt
, char *data
)
1871 ssh_pkt_adddata(pkt
, data
, strlen(data
));
1872 PUT_32BIT(pkt
->data
+ pkt
->savedpos
- 4, pkt
->length
- pkt
->savedpos
);
1874 static void ssh_pkt_addstring_data(struct Packet
*pkt
, char *data
, int len
)
1876 ssh_pkt_adddata(pkt
, data
, len
);
1877 PUT_32BIT(pkt
->data
+ pkt
->savedpos
- 4, pkt
->length
- pkt
->savedpos
);
1879 static void ssh_pkt_addstring(struct Packet
*pkt
, char *data
)
1881 ssh_pkt_addstring_start(pkt
);
1882 ssh_pkt_addstring_str(pkt
, data
);
1884 static void ssh1_pkt_addmp(struct Packet
*pkt
, Bignum b
)
1886 int len
= ssh1_bignum_length(b
);
1887 unsigned char *data
= snewn(len
, unsigned char);
1888 (void) ssh1_write_bignum(data
, b
);
1889 ssh_pkt_adddata(pkt
, data
, len
);
1892 static unsigned char *ssh2_mpint_fmt(Bignum b
, int *len
)
1895 int i
, n
= (bignum_bitcount(b
) + 7) / 8;
1896 p
= snewn(n
+ 1, unsigned char);
1898 for (i
= 1; i
<= n
; i
++)
1899 p
[i
] = bignum_byte(b
, n
- i
);
1901 while (i
<= n
&& p
[i
] == 0 && (p
[i
+ 1] & 0x80) == 0)
1903 memmove(p
, p
+ i
, n
+ 1 - i
);
1907 static void ssh2_pkt_addmp(struct Packet
*pkt
, Bignum b
)
1911 p
= ssh2_mpint_fmt(b
, &len
);
1912 ssh_pkt_addstring_start(pkt
);
1913 ssh_pkt_addstring_data(pkt
, (char *)p
, len
);
1917 static struct Packet
*ssh1_pkt_init(int pkt_type
)
1919 struct Packet
*pkt
= ssh_new_packet();
1920 pkt
->length
= 4 + 8; /* space for length + max padding */
1921 ssh_pkt_addbyte(pkt
, pkt_type
);
1922 pkt
->body
= pkt
->data
+ pkt
->length
;
1926 /* For legacy code (SSH-1 and -2 packet construction used to be separate) */
1927 #define ssh2_pkt_ensure(pkt, length) ssh_pkt_ensure(pkt, length)
1928 #define ssh2_pkt_adddata(pkt, data, len) ssh_pkt_adddata(pkt, data, len)
1929 #define ssh2_pkt_addbyte(pkt, byte) ssh_pkt_addbyte(pkt, byte)
1930 #define ssh2_pkt_adduint32(pkt, value) ssh_pkt_adduint32(pkt, value)
1931 #define ssh2_pkt_addstring_start(pkt) ssh_pkt_addstring_start(pkt)
1932 #define ssh2_pkt_addstring_str(pkt, data) ssh_pkt_addstring_str(pkt, data)
1933 #define ssh2_pkt_addstring_data(pkt, data, len) ssh_pkt_addstring_data(pkt, data, len)
1934 #define ssh2_pkt_addstring(pkt, data) ssh_pkt_addstring(pkt, data)
1936 static struct Packet
*ssh2_pkt_init(int pkt_type
)
1938 struct Packet
*pkt
= ssh_new_packet();
1939 pkt
->length
= 5; /* space for packet length + padding length */
1941 ssh_pkt_addbyte(pkt
, (unsigned char) pkt_type
);
1942 pkt
->body
= pkt
->data
+ pkt
->length
; /* after packet type */
1947 * Construct an SSH-2 final-form packet: compress it, encrypt it,
1948 * put the MAC on it. Final packet, ready to be sent, is stored in
1949 * pkt->data. Total length is returned.
1951 static int ssh2_pkt_construct(Ssh ssh
, struct Packet
*pkt
)
1953 int cipherblk
, maclen
, padding
, i
;
1956 log_packet(ssh
->logctx
, PKT_OUTGOING
, pkt
->data
[5],
1957 ssh2_pkt_type(ssh
->pkt_kctx
, ssh
->pkt_actx
, pkt
->data
[5]),
1958 pkt
->body
, pkt
->length
- (pkt
->body
- pkt
->data
),
1959 pkt
->nblanks
, pkt
->blanks
, &ssh
->v2_outgoing_sequence
);
1960 sfree(pkt
->blanks
); pkt
->blanks
= NULL
;
1964 * Compress packet payload.
1967 unsigned char *newpayload
;
1970 ssh
->cscomp
->compress(ssh
->cs_comp_ctx
, pkt
->data
+ 5,
1972 &newpayload
, &newlen
)) {
1974 ssh2_pkt_adddata(pkt
, newpayload
, newlen
);
1980 * Add padding. At least four bytes, and must also bring total
1981 * length (minus MAC) up to a multiple of the block size.
1982 * If pkt->forcepad is set, make sure the packet is at least that size
1985 cipherblk
= ssh
->cscipher ? ssh
->cscipher
->blksize
: 8; /* block size */
1986 cipherblk
= cipherblk
< 8 ?
8 : cipherblk
; /* or 8 if blksize < 8 */
1988 if (pkt
->length
+ padding
< pkt
->forcepad
)
1989 padding
= pkt
->forcepad
- pkt
->length
;
1991 (cipherblk
- (pkt
->length
+ padding
) % cipherblk
) % cipherblk
;
1992 assert(padding
<= 255);
1993 maclen
= ssh
->csmac ? ssh
->csmac
->len
: 0;
1994 ssh2_pkt_ensure(pkt
, pkt
->length
+ padding
+ maclen
);
1995 pkt
->data
[4] = padding
;
1996 for (i
= 0; i
< padding
; i
++)
1997 pkt
->data
[pkt
->length
+ i
] = random_byte();
1998 PUT_32BIT(pkt
->data
, pkt
->length
+ padding
- 4);
2000 ssh
->csmac
->generate(ssh
->cs_mac_ctx
, pkt
->data
,
2001 pkt
->length
+ padding
,
2002 ssh
->v2_outgoing_sequence
);
2003 ssh
->v2_outgoing_sequence
++; /* whether or not we MACed */
2006 ssh
->cscipher
->encrypt(ssh
->cs_cipher_ctx
,
2007 pkt
->data
, pkt
->length
+ padding
);
2009 pkt
->encrypted_len
= pkt
->length
+ padding
;
2011 /* Ready-to-send packet starts at pkt->data. We return length. */
2012 return pkt
->length
+ padding
+ maclen
;
2016 * Routines called from the main SSH code to send packets. There
2017 * are quite a few of these, because we have two separate
2018 * mechanisms for delaying the sending of packets:
2020 * - In order to send an IGNORE message and a password message in
2021 * a single fixed-length blob, we require the ability to
2022 * concatenate the encrypted forms of those two packets _into_ a
2023 * single blob and then pass it to our <network.h> transport
2024 * layer in one go. Hence, there's a deferment mechanism which
2025 * works after packet encryption.
2027 * - In order to avoid sending any connection-layer messages
2028 * during repeat key exchange, we have to queue up any such
2029 * outgoing messages _before_ they are encrypted (and in
2030 * particular before they're allocated sequence numbers), and
2031 * then send them once we've finished.
2033 * I call these mechanisms `defer' and `queue' respectively, so as
2034 * to distinguish them reasonably easily.
2036 * The functions send_noqueue() and defer_noqueue() free the packet
2037 * structure they are passed. Every outgoing packet goes through
2038 * precisely one of these functions in its life; packets passed to
2039 * ssh2_pkt_send() or ssh2_pkt_defer() either go straight to one of
2040 * these or get queued, and then when the queue is later emptied
2041 * the packets are all passed to defer_noqueue().
2043 * When using a CBC-mode cipher, it's necessary to ensure that an
2044 * attacker can't provide data to be encrypted using an IV that they
2045 * know. We ensure this by prefixing each packet that might contain
2046 * user data with an SSH_MSG_IGNORE. This is done using the deferral
2047 * mechanism, so in this case send_noqueue() ends up redirecting to
2048 * defer_noqueue(). If you don't like this inefficiency, don't use
2052 static void ssh2_pkt_defer_noqueue(Ssh
, struct Packet
*, int);
2053 static void ssh_pkt_defersend(Ssh
);
2056 * Send an SSH-2 packet immediately, without queuing or deferring.
2058 static void ssh2_pkt_send_noqueue(Ssh ssh
, struct Packet
*pkt
)
2062 if (ssh
->cscipher
!= NULL
&& (ssh
->cscipher
->flags
& SSH_CIPHER_IS_CBC
)) {
2063 /* We need to send two packets, so use the deferral mechanism. */
2064 ssh2_pkt_defer_noqueue(ssh
, pkt
, FALSE
);
2065 ssh_pkt_defersend(ssh
);
2068 len
= ssh2_pkt_construct(ssh
, pkt
);
2069 backlog
= s_write(ssh
, pkt
->data
, len
);
2070 if (backlog
> SSH_MAX_BACKLOG
)
2071 ssh_throttle_all(ssh
, 1, backlog
);
2073 ssh
->outgoing_data_size
+= pkt
->encrypted_len
;
2074 if (!ssh
->kex_in_progress
&&
2075 ssh
->max_data_size
!= 0 &&
2076 ssh
->outgoing_data_size
> ssh
->max_data_size
)
2077 do_ssh2_transport(ssh
, "too much data sent", -1, NULL
);
2079 ssh_free_packet(pkt
);
2083 * Defer an SSH-2 packet.
2085 static void ssh2_pkt_defer_noqueue(Ssh ssh
, struct Packet
*pkt
, int noignore
)
2088 if (ssh
->cscipher
!= NULL
&& (ssh
->cscipher
->flags
& SSH_CIPHER_IS_CBC
) &&
2089 ssh
->deferred_len
== 0 && !noignore
&&
2090 !(ssh
->remote_bugs
& BUG_CHOKES_ON_SSH2_IGNORE
)) {
2092 * Interpose an SSH_MSG_IGNORE to ensure that user data don't
2093 * get encrypted with a known IV.
2095 struct Packet
*ipkt
= ssh2_pkt_init(SSH2_MSG_IGNORE
);
2096 ssh2_pkt_addstring_start(ipkt
);
2097 ssh2_pkt_defer_noqueue(ssh
, ipkt
, TRUE
);
2099 len
= ssh2_pkt_construct(ssh
, pkt
);
2100 if (ssh
->deferred_len
+ len
> ssh
->deferred_size
) {
2101 ssh
->deferred_size
= ssh
->deferred_len
+ len
+ 128;
2102 ssh
->deferred_send_data
= sresize(ssh
->deferred_send_data
,
2106 memcpy(ssh
->deferred_send_data
+ ssh
->deferred_len
, pkt
->data
, len
);
2107 ssh
->deferred_len
+= len
;
2108 ssh
->deferred_data_size
+= pkt
->encrypted_len
;
2109 ssh_free_packet(pkt
);
2113 * Queue an SSH-2 packet.
2115 static void ssh2_pkt_queue(Ssh ssh
, struct Packet
*pkt
)
2117 assert(ssh
->queueing
);
2119 if (ssh
->queuelen
>= ssh
->queuesize
) {
2120 ssh
->queuesize
= ssh
->queuelen
+ 32;
2121 ssh
->queue
= sresize(ssh
->queue
, ssh
->queuesize
, struct Packet
*);
2124 ssh
->queue
[ssh
->queuelen
++] = pkt
;
2128 * Either queue or send a packet, depending on whether queueing is
2131 static void ssh2_pkt_send(Ssh ssh
, struct Packet
*pkt
)
2134 ssh2_pkt_queue(ssh
, pkt
);
2136 ssh2_pkt_send_noqueue(ssh
, pkt
);
2140 * Either queue or defer a packet, depending on whether queueing is
2143 static void ssh2_pkt_defer(Ssh ssh
, struct Packet
*pkt
)
2146 ssh2_pkt_queue(ssh
, pkt
);
2148 ssh2_pkt_defer_noqueue(ssh
, pkt
, FALSE
);
2152 * Send the whole deferred data block constructed by
2153 * ssh2_pkt_defer() or SSH-1's defer_packet().
2155 * The expected use of the defer mechanism is that you call
2156 * ssh2_pkt_defer() a few times, then call ssh_pkt_defersend(). If
2157 * not currently queueing, this simply sets up deferred_send_data
2158 * and then sends it. If we _are_ currently queueing, the calls to
2159 * ssh2_pkt_defer() put the deferred packets on to the queue
2160 * instead, and therefore ssh_pkt_defersend() has no deferred data
2161 * to send. Hence, there's no need to make it conditional on
2164 static void ssh_pkt_defersend(Ssh ssh
)
2167 backlog
= s_write(ssh
, ssh
->deferred_send_data
, ssh
->deferred_len
);
2168 ssh
->deferred_len
= ssh
->deferred_size
= 0;
2169 sfree(ssh
->deferred_send_data
);
2170 ssh
->deferred_send_data
= NULL
;
2171 if (backlog
> SSH_MAX_BACKLOG
)
2172 ssh_throttle_all(ssh
, 1, backlog
);
2174 ssh
->outgoing_data_size
+= ssh
->deferred_data_size
;
2175 if (!ssh
->kex_in_progress
&&
2176 ssh
->max_data_size
!= 0 &&
2177 ssh
->outgoing_data_size
> ssh
->max_data_size
)
2178 do_ssh2_transport(ssh
, "too much data sent", -1, NULL
);
2179 ssh
->deferred_data_size
= 0;
2183 * Send a packet whose length needs to be disguised (typically
2184 * passwords or keyboard-interactive responses).
2186 static void ssh2_pkt_send_with_padding(Ssh ssh
, struct Packet
*pkt
,
2192 * The simplest way to do this is to adjust the
2193 * variable-length padding field in the outgoing packet.
2195 * Currently compiled out, because some Cisco SSH servers
2196 * don't like excessively padded packets (bah, why's it
2199 pkt
->forcepad
= padsize
;
2200 ssh2_pkt_send(ssh
, pkt
);
2205 * If we can't do that, however, an alternative approach is
2206 * to use the pkt_defer mechanism to bundle the packet
2207 * tightly together with an SSH_MSG_IGNORE such that their
2208 * combined length is a constant. So first we construct the
2209 * final form of this packet and defer its sending.
2211 ssh2_pkt_defer(ssh
, pkt
);
2214 * Now construct an SSH_MSG_IGNORE which includes a string
2215 * that's an exact multiple of the cipher block size. (If
2216 * the cipher is NULL so that the block size is
2217 * unavailable, we don't do this trick at all, because we
2218 * gain nothing by it.)
2220 if (ssh
->cscipher
&&
2221 !(ssh
->remote_bugs
& BUG_CHOKES_ON_SSH2_IGNORE
)) {
2224 stringlen
= (256 - ssh
->deferred_len
);
2225 stringlen
+= ssh
->cscipher
->blksize
- 1;
2226 stringlen
-= (stringlen
% ssh
->cscipher
->blksize
);
2229 * Temporarily disable actual compression, so we
2230 * can guarantee to get this string exactly the
2231 * length we want it. The compression-disabling
2232 * routine should return an integer indicating how
2233 * many bytes we should adjust our string length
2237 ssh
->cscomp
->disable_compression(ssh
->cs_comp_ctx
);
2239 pkt
= ssh2_pkt_init(SSH2_MSG_IGNORE
);
2240 ssh2_pkt_addstring_start(pkt
);
2241 for (i
= 0; i
< stringlen
; i
++) {
2242 char c
= (char) random_byte();
2243 ssh2_pkt_addstring_data(pkt
, &c
, 1);
2245 ssh2_pkt_defer(ssh
, pkt
);
2247 ssh_pkt_defersend(ssh
);
2252 * Send all queued SSH-2 packets. We send them by means of
2253 * ssh2_pkt_defer_noqueue(), in case they included a pair of
2254 * packets that needed to be lumped together.
2256 static void ssh2_pkt_queuesend(Ssh ssh
)
2260 assert(!ssh
->queueing
);
2262 for (i
= 0; i
< ssh
->queuelen
; i
++)
2263 ssh2_pkt_defer_noqueue(ssh
, ssh
->queue
[i
], FALSE
);
2266 ssh_pkt_defersend(ssh
);
2270 void bndebug(char *string
, Bignum b
)
2274 p
= ssh2_mpint_fmt(b
, &len
);
2275 debug(("%s", string
));
2276 for (i
= 0; i
< len
; i
++)
2277 debug((" %02x", p
[i
]));
2283 static void hash_mpint(const struct ssh_hash
*h
, void *s
, Bignum b
)
2287 p
= ssh2_mpint_fmt(b
, &len
);
2288 hash_string(h
, s
, p
, len
);
2293 * Packet decode functions for both SSH-1 and SSH-2.
2295 static unsigned long ssh_pkt_getuint32(struct Packet
*pkt
)
2297 unsigned long value
;
2298 if (pkt
->length
- pkt
->savedpos
< 4)
2299 return 0; /* arrgh, no way to decline (FIXME?) */
2300 value
= GET_32BIT(pkt
->body
+ pkt
->savedpos
);
2304 static int ssh2_pkt_getbool(struct Packet
*pkt
)
2306 unsigned long value
;
2307 if (pkt
->length
- pkt
->savedpos
< 1)
2308 return 0; /* arrgh, no way to decline (FIXME?) */
2309 value
= pkt
->body
[pkt
->savedpos
] != 0;
2313 static void ssh_pkt_getstring(struct Packet
*pkt
, char **p
, int *length
)
2318 if (pkt
->length
- pkt
->savedpos
< 4)
2320 len
= GET_32BIT(pkt
->body
+ pkt
->savedpos
);
2325 if (pkt
->length
- pkt
->savedpos
< *length
)
2327 *p
= (char *)(pkt
->body
+ pkt
->savedpos
);
2328 pkt
->savedpos
+= *length
;
2330 static void *ssh_pkt_getdata(struct Packet
*pkt
, int length
)
2332 if (pkt
->length
- pkt
->savedpos
< length
)
2334 pkt
->savedpos
+= length
;
2335 return pkt
->body
+ (pkt
->savedpos
- length
);
2337 static int ssh1_pkt_getrsakey(struct Packet
*pkt
, struct RSAKey
*key
,
2338 unsigned char **keystr
)
2342 j
= makekey(pkt
->body
+ pkt
->savedpos
,
2343 pkt
->length
- pkt
->savedpos
,
2350 assert(pkt
->savedpos
< pkt
->length
);
2354 static Bignum
ssh1_pkt_getmp(struct Packet
*pkt
)
2359 j
= ssh1_read_bignum(pkt
->body
+ pkt
->savedpos
,
2360 pkt
->length
- pkt
->savedpos
, &b
);
2368 static Bignum
ssh2_pkt_getmp(struct Packet
*pkt
)
2374 ssh_pkt_getstring(pkt
, &p
, &length
);
2379 b
= bignum_from_bytes((unsigned char *)p
, length
);
2384 * Helper function to add an SSH-2 signature blob to a packet.
2385 * Expects to be shown the public key blob as well as the signature
2386 * blob. Normally works just like ssh2_pkt_addstring, but will
2387 * fiddle with the signature packet if necessary for
2388 * BUG_SSH2_RSA_PADDING.
2390 static void ssh2_add_sigblob(Ssh ssh
, struct Packet
*pkt
,
2391 void *pkblob_v
, int pkblob_len
,
2392 void *sigblob_v
, int sigblob_len
)
2394 unsigned char *pkblob
= (unsigned char *)pkblob_v
;
2395 unsigned char *sigblob
= (unsigned char *)sigblob_v
;
2397 /* dmemdump(pkblob, pkblob_len); */
2398 /* dmemdump(sigblob, sigblob_len); */
2401 * See if this is in fact an ssh-rsa signature and a buggy
2402 * server; otherwise we can just do this the easy way.
2404 if ((ssh
->remote_bugs
& BUG_SSH2_RSA_PADDING
) &&
2405 (GET_32BIT(pkblob
) == 7 && !memcmp(pkblob
+4, "ssh-rsa", 7))) {
2406 int pos
, len
, siglen
;
2409 * Find the byte length of the modulus.
2412 pos
= 4+7; /* skip over "ssh-rsa" */
2413 pos
+= 4 + GET_32BIT(pkblob
+pos
); /* skip over exponent */
2414 len
= GET_32BIT(pkblob
+pos
); /* find length of modulus */
2415 pos
+= 4; /* find modulus itself */
2416 while (len
> 0 && pkblob
[pos
] == 0)
2418 /* debug(("modulus length is %d\n", len)); */
2421 * Now find the signature integer.
2423 pos
= 4+7; /* skip over "ssh-rsa" */
2424 siglen
= GET_32BIT(sigblob
+pos
);
2425 /* debug(("signature length is %d\n", siglen)); */
2427 if (len
!= siglen
) {
2428 unsigned char newlen
[4];
2429 ssh2_pkt_addstring_start(pkt
);
2430 ssh2_pkt_addstring_data(pkt
, (char *)sigblob
, pos
);
2431 /* dmemdump(sigblob, pos); */
2432 pos
+= 4; /* point to start of actual sig */
2433 PUT_32BIT(newlen
, len
);
2434 ssh2_pkt_addstring_data(pkt
, (char *)newlen
, 4);
2435 /* dmemdump(newlen, 4); */
2437 while (len
-- > siglen
) {
2438 ssh2_pkt_addstring_data(pkt
, (char *)newlen
, 1);
2439 /* dmemdump(newlen, 1); */
2441 ssh2_pkt_addstring_data(pkt
, (char *)(sigblob
+pos
), siglen
);
2442 /* dmemdump(sigblob+pos, siglen); */
2446 /* Otherwise fall through and do it the easy way. */
2449 ssh2_pkt_addstring_start(pkt
);
2450 ssh2_pkt_addstring_data(pkt
, (char *)sigblob
, sigblob_len
);
2454 * Examine the remote side's version string and compare it against
2455 * a list of known buggy implementations.
2457 static void ssh_detect_bugs(Ssh ssh
, char *vstring
)
2459 char *imp
; /* pointer to implementation part */
2461 imp
+= strcspn(imp
, "-");
2463 imp
+= strcspn(imp
, "-");
2466 ssh
->remote_bugs
= 0;
2469 * General notes on server version strings:
2470 * - Not all servers reporting "Cisco-1.25" have all the bugs listed
2471 * here -- in particular, we've heard of one that's perfectly happy
2472 * with SSH1_MSG_IGNOREs -- but this string never seems to change,
2473 * so we can't distinguish them.
2475 if (conf_get_int(ssh
->conf
, CONF_sshbug_ignore1
) == FORCE_ON
||
2476 (conf_get_int(ssh
->conf
, CONF_sshbug_ignore1
) == AUTO
&&
2477 (!strcmp(imp
, "1.2.18") || !strcmp(imp
, "1.2.19") ||
2478 !strcmp(imp
, "1.2.20") || !strcmp(imp
, "1.2.21") ||
2479 !strcmp(imp
, "1.2.22") || !strcmp(imp
, "Cisco-1.25") ||
2480 !strcmp(imp
, "OSU_1.4alpha3") || !strcmp(imp
, "OSU_1.5alpha4")))) {
2482 * These versions don't support SSH1_MSG_IGNORE, so we have
2483 * to use a different defence against password length
2486 ssh
->remote_bugs
|= BUG_CHOKES_ON_SSH1_IGNORE
;
2487 logevent("We believe remote version has SSH-1 ignore bug");
2490 if (conf_get_int(ssh
->conf
, CONF_sshbug_plainpw1
) == FORCE_ON
||
2491 (conf_get_int(ssh
->conf
, CONF_sshbug_plainpw1
) == AUTO
&&
2492 (!strcmp(imp
, "Cisco-1.25") || !strcmp(imp
, "OSU_1.4alpha3")))) {
2494 * These versions need a plain password sent; they can't
2495 * handle having a null and a random length of data after
2498 ssh
->remote_bugs
|= BUG_NEEDS_SSH1_PLAIN_PASSWORD
;
2499 logevent("We believe remote version needs a plain SSH-1 password");
2502 if (conf_get_int(ssh
->conf
, CONF_sshbug_rsa1
) == FORCE_ON
||
2503 (conf_get_int(ssh
->conf
, CONF_sshbug_rsa1
) == AUTO
&&
2504 (!strcmp(imp
, "Cisco-1.25")))) {
2506 * These versions apparently have no clue whatever about
2507 * RSA authentication and will panic and die if they see
2508 * an AUTH_RSA message.
2510 ssh
->remote_bugs
|= BUG_CHOKES_ON_RSA
;
2511 logevent("We believe remote version can't handle SSH-1 RSA authentication");
2514 if (conf_get_int(ssh
->conf
, CONF_sshbug_hmac2
) == FORCE_ON
||
2515 (conf_get_int(ssh
->conf
, CONF_sshbug_hmac2
) == AUTO
&&
2516 !wc_match("* VShell", imp
) &&
2517 (wc_match("2.1.0*", imp
) || wc_match("2.0.*", imp
) ||
2518 wc_match("2.2.0*", imp
) || wc_match("2.3.0*", imp
) ||
2519 wc_match("2.1 *", imp
)))) {
2521 * These versions have the HMAC bug.
2523 ssh
->remote_bugs
|= BUG_SSH2_HMAC
;
2524 logevent("We believe remote version has SSH-2 HMAC bug");
2527 if (conf_get_int(ssh
->conf
, CONF_sshbug_derivekey2
) == FORCE_ON
||
2528 (conf_get_int(ssh
->conf
, CONF_sshbug_derivekey2
) == AUTO
&&
2529 !wc_match("* VShell", imp
) &&
2530 (wc_match("2.0.0*", imp
) || wc_match("2.0.10*", imp
) ))) {
2532 * These versions have the key-derivation bug (failing to
2533 * include the literal shared secret in the hashes that
2534 * generate the keys).
2536 ssh
->remote_bugs
|= BUG_SSH2_DERIVEKEY
;
2537 logevent("We believe remote version has SSH-2 key-derivation bug");
2540 if (conf_get_int(ssh
->conf
, CONF_sshbug_rsapad2
) == FORCE_ON
||
2541 (conf_get_int(ssh
->conf
, CONF_sshbug_rsapad2
) == AUTO
&&
2542 (wc_match("OpenSSH_2.[5-9]*", imp
) ||
2543 wc_match("OpenSSH_3.[0-2]*", imp
)))) {
2545 * These versions have the SSH-2 RSA padding bug.
2547 ssh
->remote_bugs
|= BUG_SSH2_RSA_PADDING
;
2548 logevent("We believe remote version has SSH-2 RSA padding bug");
2551 if (conf_get_int(ssh
->conf
, CONF_sshbug_pksessid2
) == FORCE_ON
||
2552 (conf_get_int(ssh
->conf
, CONF_sshbug_pksessid2
) == AUTO
&&
2553 wc_match("OpenSSH_2.[0-2]*", imp
))) {
2555 * These versions have the SSH-2 session-ID bug in
2556 * public-key authentication.
2558 ssh
->remote_bugs
|= BUG_SSH2_PK_SESSIONID
;
2559 logevent("We believe remote version has SSH-2 public-key-session-ID bug");
2562 if (conf_get_int(ssh
->conf
, CONF_sshbug_rekey2
) == FORCE_ON
||
2563 (conf_get_int(ssh
->conf
, CONF_sshbug_rekey2
) == AUTO
&&
2564 (wc_match("DigiSSH_2.0", imp
) ||
2565 wc_match("OpenSSH_2.[0-4]*", imp
) ||
2566 wc_match("OpenSSH_2.5.[0-3]*", imp
) ||
2567 wc_match("Sun_SSH_1.0", imp
) ||
2568 wc_match("Sun_SSH_1.0.1", imp
) ||
2569 /* All versions <= 1.2.6 (they changed their format in 1.2.7) */
2570 wc_match("WeOnlyDo-*", imp
)))) {
2572 * These versions have the SSH-2 rekey bug.
2574 ssh
->remote_bugs
|= BUG_SSH2_REKEY
;
2575 logevent("We believe remote version has SSH-2 rekey bug");
2578 if (conf_get_int(ssh
->conf
, CONF_sshbug_maxpkt2
) == FORCE_ON
||
2579 (conf_get_int(ssh
->conf
, CONF_sshbug_maxpkt2
) == AUTO
&&
2580 (wc_match("1.36_sshlib GlobalSCAPE", imp
) ||
2581 wc_match("1.36 sshlib: GlobalScape", imp
)))) {
2583 * This version ignores our makpkt and needs to be throttled.
2585 ssh
->remote_bugs
|= BUG_SSH2_MAXPKT
;
2586 logevent("We believe remote version ignores SSH-2 maximum packet size");
2589 if (conf_get_int(ssh
->conf
, CONF_sshbug_ignore2
) == FORCE_ON
) {
2591 * Servers that don't support SSH2_MSG_IGNORE. Currently,
2592 * none detected automatically.
2594 ssh
->remote_bugs
|= BUG_CHOKES_ON_SSH2_IGNORE
;
2595 logevent("We believe remote version has SSH-2 ignore bug");
2598 if (conf_get_int(ssh
->conf
, CONF_sshbug_winadj
) == FORCE_ON
) {
2600 * Servers that don't support our winadj request for one
2601 * reason or another. Currently, none detected automatically.
2603 ssh
->remote_bugs
|= BUG_CHOKES_ON_WINADJ
;
2604 logevent("We believe remote version has winadj bug");
2609 * The `software version' part of an SSH version string is required
2610 * to contain no spaces or minus signs.
2612 static void ssh_fix_verstring(char *str
)
2614 /* Eat "SSH-<protoversion>-". */
2615 assert(*str
== 'S'); str
++;
2616 assert(*str
== 'S'); str
++;
2617 assert(*str
== 'H'); str
++;
2618 assert(*str
== '-'); str
++;
2619 while (*str
&& *str
!= '-') str
++;
2620 assert(*str
== '-'); str
++;
2622 /* Convert minus signs and spaces in the remaining string into
2625 if (*str
== '-' || *str
== ' ')
2632 * Send an appropriate SSH version string.
2634 static void ssh_send_verstring(Ssh ssh
, char *svers
)
2638 if (ssh
->version
== 2) {
2640 * Construct a v2 version string.
2642 verstring
= dupprintf("SSH-2.0-%s\015\012", sshver
);
2645 * Construct a v1 version string.
2647 verstring
= dupprintf("SSH-%s-%s\012",
2648 (ssh_versioncmp(svers
, "1.5") <= 0 ?
2653 ssh_fix_verstring(verstring
);
2655 if (ssh
->version
== 2) {
2658 * Record our version string.
2660 len
= strcspn(verstring
, "\015\012");
2661 ssh
->v_c
= snewn(len
+ 1, char);
2662 memcpy(ssh
->v_c
, verstring
, len
);
2666 logeventf(ssh
, "We claim version: %.*s",
2667 strcspn(verstring
, "\015\012"), verstring
);
2668 s_write(ssh
, verstring
, strlen(verstring
));
2672 static int do_ssh_init(Ssh ssh
, unsigned char c
)
2674 struct do_ssh_init_state
{
2683 crState(do_ssh_init_state
);
2687 /* Search for a line beginning with the string "SSH-" in the input. */
2689 if (c
!= 'S') goto no
;
2691 if (c
!= 'S') goto no
;
2693 if (c
!= 'H') goto no
;
2695 if (c
!= '-') goto no
;
2704 s
->vstring
= snewn(s
->vstrsize
, char);
2705 strcpy(s
->vstring
, "SSH-");
2709 crReturn(1); /* get another char */
2710 if (s
->vslen
>= s
->vstrsize
- 1) {
2712 s
->vstring
= sresize(s
->vstring
, s
->vstrsize
, char);
2714 s
->vstring
[s
->vslen
++] = c
;
2717 s
->version
[s
->i
] = '\0';
2719 } else if (s
->i
< sizeof(s
->version
) - 1)
2720 s
->version
[s
->i
++] = c
;
2721 } else if (c
== '\012')
2725 ssh
->agentfwd_enabled
= FALSE
;
2726 ssh
->rdpkt2_state
.incoming_sequence
= 0;
2728 s
->vstring
[s
->vslen
] = 0;
2729 s
->vstring
[strcspn(s
->vstring
, "\015\012")] = '\0';/* remove EOL chars */
2730 logeventf(ssh
, "Server version: %s", s
->vstring
);
2731 ssh_detect_bugs(ssh
, s
->vstring
);
2734 * Decide which SSH protocol version to support.
2737 /* Anything strictly below "2.0" means protocol 1 is supported. */
2738 s
->proto1
= ssh_versioncmp(s
->version
, "2.0") < 0;
2739 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
2740 s
->proto2
= ssh_versioncmp(s
->version
, "1.99") >= 0;
2742 if (conf_get_int(ssh
->conf
, CONF_sshprot
) == 0 && !s
->proto1
) {
2743 bombout(("SSH protocol version 1 required by user but not provided by server"));
2746 if (conf_get_int(ssh
->conf
, CONF_sshprot
) == 3 && !s
->proto2
) {
2747 bombout(("SSH protocol version 2 required by user but not provided by server"));
2751 if (s
->proto2
&& (conf_get_int(ssh
->conf
, CONF_sshprot
) >= 2 || !s
->proto1
))
2756 logeventf(ssh
, "Using SSH protocol version %d", ssh
->version
);
2758 /* Send the version string, if we haven't already */
2759 if (conf_get_int(ssh
->conf
, CONF_sshprot
) != 3)
2760 ssh_send_verstring(ssh
, s
->version
);
2762 if (ssh
->version
== 2) {
2765 * Record their version string.
2767 len
= strcspn(s
->vstring
, "\015\012");
2768 ssh
->v_s
= snewn(len
+ 1, char);
2769 memcpy(ssh
->v_s
, s
->vstring
, len
);
2773 * Initialise SSH-2 protocol.
2775 ssh
->protocol
= ssh2_protocol
;
2776 ssh2_protocol_setup(ssh
);
2777 ssh
->s_rdpkt
= ssh2_rdpkt
;
2780 * Initialise SSH-1 protocol.
2782 ssh
->protocol
= ssh1_protocol
;
2783 ssh1_protocol_setup(ssh
);
2784 ssh
->s_rdpkt
= ssh1_rdpkt
;
2786 if (ssh
->version
== 2)
2787 do_ssh2_transport(ssh
, NULL
, -1, NULL
);
2789 update_specials_menu(ssh
->frontend
);
2790 ssh
->state
= SSH_STATE_BEFORE_SIZE
;
2791 ssh
->pinger
= pinger_new(ssh
->conf
, &ssh_backend
, ssh
);
2798 static void ssh_process_incoming_data(Ssh ssh
,
2799 unsigned char **data
, int *datalen
)
2801 struct Packet
*pktin
;
2803 pktin
= ssh
->s_rdpkt(ssh
, data
, datalen
);
2805 ssh
->protocol(ssh
, NULL
, 0, pktin
);
2806 ssh_free_packet(pktin
);
2810 static void ssh_queue_incoming_data(Ssh ssh
,
2811 unsigned char **data
, int *datalen
)
2813 bufchain_add(&ssh
->queued_incoming_data
, *data
, *datalen
);
2818 static void ssh_process_queued_incoming_data(Ssh ssh
)
2821 unsigned char *data
;
2824 while (!ssh
->frozen
&& bufchain_size(&ssh
->queued_incoming_data
)) {
2825 bufchain_prefix(&ssh
->queued_incoming_data
, &vdata
, &len
);
2829 while (!ssh
->frozen
&& len
> 0)
2830 ssh_process_incoming_data(ssh
, &data
, &len
);
2833 bufchain_consume(&ssh
->queued_incoming_data
, origlen
- len
);
2837 static void ssh_set_frozen(Ssh ssh
, int frozen
)
2840 sk_set_frozen(ssh
->s
, frozen
);
2841 ssh
->frozen
= frozen
;
2844 static void ssh_gotdata(Ssh ssh
, unsigned char *data
, int datalen
)
2846 /* Log raw data, if we're in that mode. */
2848 log_packet(ssh
->logctx
, PKT_INCOMING
, -1, NULL
, data
, datalen
,
2851 crBegin(ssh
->ssh_gotdata_crstate
);
2854 * To begin with, feed the characters one by one to the
2855 * protocol initialisation / selection function do_ssh_init().
2856 * When that returns 0, we're done with the initial greeting
2857 * exchange and can move on to packet discipline.
2860 int ret
; /* need not be kept across crReturn */
2862 crReturnV
; /* more data please */
2863 ret
= do_ssh_init(ssh
, *data
);
2871 * We emerge from that loop when the initial negotiation is
2872 * over and we have selected an s_rdpkt function. Now pass
2873 * everything to s_rdpkt, and then pass the resulting packets
2874 * to the proper protocol handler.
2878 while (bufchain_size(&ssh
->queued_incoming_data
) > 0 || datalen
> 0) {
2880 ssh_queue_incoming_data(ssh
, &data
, &datalen
);
2881 /* This uses up all data and cannot cause anything interesting
2882 * to happen; indeed, for anything to happen at all, we must
2883 * return, so break out. */
2885 } else if (bufchain_size(&ssh
->queued_incoming_data
) > 0) {
2886 /* This uses up some or all data, and may freeze the
2888 ssh_process_queued_incoming_data(ssh
);
2890 /* This uses up some or all data, and may freeze the
2892 ssh_process_incoming_data(ssh
, &data
, &datalen
);
2894 /* FIXME this is probably EBW. */
2895 if (ssh
->state
== SSH_STATE_CLOSED
)
2898 /* We're out of data. Go and get some more. */
2904 static int ssh_do_close(Ssh ssh
, int notify_exit
)
2907 struct ssh_channel
*c
;
2909 ssh
->state
= SSH_STATE_CLOSED
;
2910 expire_timer_context(ssh
);
2915 notify_remote_exit(ssh
->frontend
);
2920 * Now we must shut down any port- and X-forwarded channels going
2921 * through this connection.
2923 if (ssh
->channels
) {
2924 while (NULL
!= (c
= index234(ssh
->channels
, 0))) {
2927 x11_close(c
->u
.x11
.s
);
2930 case CHAN_SOCKDATA_DORMANT
:
2931 pfd_close(c
->u
.pfd
.s
);
2934 del234(ssh
->channels
, c
); /* moving next one to index 0 */
2935 if (ssh
->version
== 2)
2936 bufchain_clear(&c
->v
.v2
.outbuffer
);
2941 * Go through port-forwardings, and close any associated
2942 * listening sockets.
2944 if (ssh
->portfwds
) {
2945 struct ssh_portfwd
*pf
;
2946 while (NULL
!= (pf
= index234(ssh
->portfwds
, 0))) {
2947 /* Dispose of any listening socket. */
2949 pfd_terminate(pf
->local
);
2950 del234(ssh
->portfwds
, pf
); /* moving next one to index 0 */
2953 freetree234(ssh
->portfwds
);
2954 ssh
->portfwds
= NULL
;
2960 static void ssh_log(Plug plug
, int type
, SockAddr addr
, int port
,
2961 const char *error_msg
, int error_code
)
2963 Ssh ssh
= (Ssh
) plug
;
2964 char addrbuf
[256], *msg
;
2966 sk_getaddr(addr
, addrbuf
, lenof(addrbuf
));
2969 msg
= dupprintf("Connecting to %s port %d", addrbuf
, port
);
2971 msg
= dupprintf("Failed to connect to %s: %s", addrbuf
, error_msg
);
2977 static int ssh_closing(Plug plug
, const char *error_msg
, int error_code
,
2980 Ssh ssh
= (Ssh
) plug
;
2981 int need_notify
= ssh_do_close(ssh
, FALSE
);
2984 if (!ssh
->close_expected
)
2985 error_msg
= "Server unexpectedly closed network connection";
2987 error_msg
= "Server closed network connection";
2990 if (ssh
->close_expected
&& ssh
->clean_exit
&& ssh
->exitcode
< 0)
2994 notify_remote_exit(ssh
->frontend
);
2997 logevent(error_msg
);
2998 if (!ssh
->close_expected
|| !ssh
->clean_exit
)
2999 connection_fatal(ssh
->frontend
, "%s", error_msg
);
3003 static int ssh_receive(Plug plug
, int urgent
, char *data
, int len
)
3005 Ssh ssh
= (Ssh
) plug
;
3006 ssh_gotdata(ssh
, (unsigned char *)data
, len
);
3007 if (ssh
->state
== SSH_STATE_CLOSED
) {
3008 ssh_do_close(ssh
, TRUE
);
3014 static void ssh_sent(Plug plug
, int bufsize
)
3016 Ssh ssh
= (Ssh
) plug
;
3018 * If the send backlog on the SSH socket itself clears, we
3019 * should unthrottle the whole world if it was throttled.
3021 if (bufsize
< SSH_MAX_BACKLOG
)
3022 ssh_throttle_all(ssh
, 0, bufsize
);
3026 * Connect to specified host and port.
3027 * Returns an error message, or NULL on success.
3028 * Also places the canonical host name into `realhost'. It must be
3029 * freed by the caller.
3031 static const char *connect_to_host(Ssh ssh
, char *host
, int port
,
3032 char **realhost
, int nodelay
, int keepalive
)
3034 static const struct plug_function_table fn_table
= {
3045 int addressfamily
, sshprot
;
3047 loghost
= conf_get_str(ssh
->conf
, CONF_loghost
);
3051 ssh
->savedhost
= dupstr(loghost
);
3052 ssh
->savedport
= 22; /* default ssh port */
3055 * A colon suffix on savedhost also lets us affect
3058 * (FIXME: do something about IPv6 address literals here.)
3060 colon
= strrchr(ssh
->savedhost
, ':');
3064 ssh
->savedport
= atoi(colon
);
3067 ssh
->savedhost
= dupstr(host
);
3069 port
= 22; /* default ssh port */
3070 ssh
->savedport
= port
;
3076 addressfamily
= conf_get_int(ssh
->conf
, CONF_addressfamily
);
3077 logeventf(ssh
, "Looking up host \"%s\"%s", host
,
3078 (addressfamily
== ADDRTYPE_IPV4 ?
" (IPv4)" :
3079 (addressfamily
== ADDRTYPE_IPV6 ?
" (IPv6)" : "")));
3080 addr
= name_lookup(host
, port
, realhost
, ssh
->conf
, addressfamily
);
3081 if ((err
= sk_addr_error(addr
)) != NULL
) {
3085 ssh
->fullhostname
= dupstr(*realhost
); /* save in case of GSSAPI */
3090 ssh
->fn
= &fn_table
;
3091 ssh
->s
= new_connection(addr
, *realhost
, port
,
3092 0, 1, nodelay
, keepalive
, (Plug
) ssh
, ssh
->conf
);
3093 if ((err
= sk_socket_error(ssh
->s
)) != NULL
) {
3095 notify_remote_exit(ssh
->frontend
);
3100 * If the SSH version number's fixed, set it now, and if it's SSH-2,
3101 * send the version string too.
3103 sshprot
= conf_get_int(ssh
->conf
, CONF_sshprot
);
3108 ssh_send_verstring(ssh
, NULL
);
3112 * loghost, if configured, overrides realhost.
3116 *realhost
= dupstr(loghost
);
3123 * Throttle or unthrottle the SSH connection.
3125 static void ssh_throttle_conn(Ssh ssh
, int adjust
)
3127 int old_count
= ssh
->conn_throttle_count
;
3128 ssh
->conn_throttle_count
+= adjust
;
3129 assert(ssh
->conn_throttle_count
>= 0);
3130 if (ssh
->conn_throttle_count
&& !old_count
) {
3131 ssh_set_frozen(ssh
, 1);
3132 } else if (!ssh
->conn_throttle_count
&& old_count
) {
3133 ssh_set_frozen(ssh
, 0);
3138 * Throttle or unthrottle _all_ local data streams (for when sends
3139 * on the SSH connection itself back up).
3141 static void ssh_throttle_all(Ssh ssh
, int enable
, int bufsize
)
3144 struct ssh_channel
*c
;
3146 if (enable
== ssh
->throttled_all
)
3148 ssh
->throttled_all
= enable
;
3149 ssh
->overall_bufsize
= bufsize
;
3152 for (i
= 0; NULL
!= (c
= index234(ssh
->channels
, i
)); i
++) {
3154 case CHAN_MAINSESSION
:
3156 * This is treated separately, outside the switch.
3160 x11_override_throttle(c
->u
.x11
.s
, enable
);
3163 /* Agent channels require no buffer management. */
3166 pfd_override_throttle(c
->u
.pfd
.s
, enable
);
3172 static void ssh_agent_callback(void *sshv
, void *reply
, int replylen
)
3174 Ssh ssh
= (Ssh
) sshv
;
3176 ssh
->agent_response
= reply
;
3177 ssh
->agent_response_len
= replylen
;
3179 if (ssh
->version
== 1)
3180 do_ssh1_login(ssh
, NULL
, -1, NULL
);
3182 do_ssh2_authconn(ssh
, NULL
, -1, NULL
);
3185 static void ssh_dialog_callback(void *sshv
, int ret
)
3187 Ssh ssh
= (Ssh
) sshv
;
3189 ssh
->user_response
= ret
;
3191 if (ssh
->version
== 1)
3192 do_ssh1_login(ssh
, NULL
, -1, NULL
);
3194 do_ssh2_transport(ssh
, NULL
, -1, NULL
);
3197 * This may have unfrozen the SSH connection, so do a
3200 ssh_process_queued_incoming_data(ssh
);
3203 static void ssh_agentf_callback(void *cv
, void *reply
, int replylen
)
3205 struct ssh_channel
*c
= (struct ssh_channel
*)cv
;
3207 void *sentreply
= reply
;
3210 /* Fake SSH_AGENT_FAILURE. */
3211 sentreply
= "\0\0\0\1\5";
3214 if (ssh
->version
== 2) {
3215 ssh2_add_channel_data(c
, sentreply
, replylen
);
3218 send_packet(ssh
, SSH1_MSG_CHANNEL_DATA
,
3219 PKT_INT
, c
->remoteid
,
3222 PKT_DATA
, sentreply
, replylen
,
3231 * Client-initiated disconnection. Send a DISCONNECT if `wire_reason'
3232 * non-NULL, otherwise just close the connection. `client_reason' == NULL
3233 * => log `wire_reason'.
3235 static void ssh_disconnect(Ssh ssh
, char *client_reason
, char *wire_reason
,
3236 int code
, int clean_exit
)
3240 client_reason
= wire_reason
;
3242 error
= dupprintf("Disconnected: %s", client_reason
);
3244 error
= dupstr("Disconnected");
3246 if (ssh
->version
== 1) {
3247 send_packet(ssh
, SSH1_MSG_DISCONNECT
, PKT_STR
, wire_reason
,
3249 } else if (ssh
->version
== 2) {
3250 struct Packet
*pktout
= ssh2_pkt_init(SSH2_MSG_DISCONNECT
);
3251 ssh2_pkt_adduint32(pktout
, code
);
3252 ssh2_pkt_addstring(pktout
, wire_reason
);
3253 ssh2_pkt_addstring(pktout
, "en"); /* language tag */
3254 ssh2_pkt_send_noqueue(ssh
, pktout
);
3257 ssh
->close_expected
= TRUE
;
3258 ssh
->clean_exit
= clean_exit
;
3259 ssh_closing((Plug
)ssh
, error
, 0, 0);
3264 * Handle the key exchange and user authentication phases.
3266 static int do_ssh1_login(Ssh ssh
, unsigned char *in
, int inlen
,
3267 struct Packet
*pktin
)
3270 unsigned char cookie
[8], *ptr
;
3271 struct RSAKey servkey
, hostkey
;
3272 struct MD5Context md5c
;
3273 struct do_ssh1_login_state
{
3276 unsigned char *rsabuf
, *keystr1
, *keystr2
;
3277 unsigned long supported_ciphers_mask
, supported_auths_mask
;
3278 int tried_publickey
, tried_agent
;
3279 int tis_auth_refused
, ccard_auth_refused
;
3280 unsigned char session_id
[16];
3282 void *publickey_blob
;
3283 int publickey_bloblen
;
3284 char *publickey_comment
;
3285 int publickey_encrypted
;
3286 prompts_t
*cur_prompt
;
3289 unsigned char request
[5], *response
, *p
;
3300 crState(do_ssh1_login_state
);
3307 if (pktin
->type
!= SSH1_SMSG_PUBLIC_KEY
) {
3308 bombout(("Public key packet not received"));
3312 logevent("Received public keys");
3314 ptr
= ssh_pkt_getdata(pktin
, 8);
3316 bombout(("SSH-1 public key packet stopped before random cookie"));
3319 memcpy(cookie
, ptr
, 8);
3321 if (!ssh1_pkt_getrsakey(pktin
, &servkey
, &s
->keystr1
) ||
3322 !ssh1_pkt_getrsakey(pktin
, &hostkey
, &s
->keystr2
)) {
3323 bombout(("Failed to read SSH-1 public keys from public key packet"));
3328 * Log the host key fingerprint.
3332 logevent("Host key fingerprint is:");
3333 strcpy(logmsg
, " ");
3334 hostkey
.comment
= NULL
;
3335 rsa_fingerprint(logmsg
+ strlen(logmsg
),
3336 sizeof(logmsg
) - strlen(logmsg
), &hostkey
);
3340 ssh
->v1_remote_protoflags
= ssh_pkt_getuint32(pktin
);
3341 s
->supported_ciphers_mask
= ssh_pkt_getuint32(pktin
);
3342 s
->supported_auths_mask
= ssh_pkt_getuint32(pktin
);
3343 if ((ssh
->remote_bugs
& BUG_CHOKES_ON_RSA
))
3344 s
->supported_auths_mask
&= ~(1 << SSH1_AUTH_RSA
);
3346 ssh
->v1_local_protoflags
=
3347 ssh
->v1_remote_protoflags
& SSH1_PROTOFLAGS_SUPPORTED
;
3348 ssh
->v1_local_protoflags
|= SSH1_PROTOFLAG_SCREEN_NUMBER
;
3351 MD5Update(&md5c
, s
->keystr2
, hostkey
.bytes
);
3352 MD5Update(&md5c
, s
->keystr1
, servkey
.bytes
);
3353 MD5Update(&md5c
, cookie
, 8);
3354 MD5Final(s
->session_id
, &md5c
);
3356 for (i
= 0; i
< 32; i
++)
3357 ssh
->session_key
[i
] = random_byte();
3360 * Verify that the `bits' and `bytes' parameters match.
3362 if (hostkey
.bits
> hostkey
.bytes
* 8 ||
3363 servkey
.bits
> servkey
.bytes
* 8) {
3364 bombout(("SSH-1 public keys were badly formatted"));
3368 s
->len
= (hostkey
.bytes
> servkey
.bytes ? hostkey
.bytes
: servkey
.bytes
);
3370 s
->rsabuf
= snewn(s
->len
, unsigned char);
3373 * Verify the host key.
3377 * First format the key into a string.
3379 int len
= rsastr_len(&hostkey
);
3380 char fingerprint
[100];
3381 char *keystr
= snewn(len
, char);
3382 rsastr_fmt(keystr
, &hostkey
);
3383 rsa_fingerprint(fingerprint
, sizeof(fingerprint
), &hostkey
);
3385 ssh_set_frozen(ssh
, 1);
3386 s
->dlgret
= verify_ssh_host_key(ssh
->frontend
,
3387 ssh
->savedhost
, ssh
->savedport
,
3388 "rsa", keystr
, fingerprint
,
3389 ssh_dialog_callback
, ssh
);
3391 if (s
->dlgret
< 0) {
3395 bombout(("Unexpected data from server while waiting"
3396 " for user host key response"));
3399 } while (pktin
|| inlen
> 0);
3400 s
->dlgret
= ssh
->user_response
;
3402 ssh_set_frozen(ssh
, 0);
3404 if (s
->dlgret
== 0) {
3405 ssh_disconnect(ssh
, "User aborted at host key verification",
3411 for (i
= 0; i
< 32; i
++) {
3412 s
->rsabuf
[i
] = ssh
->session_key
[i
];
3414 s
->rsabuf
[i
] ^= s
->session_id
[i
];
3417 if (hostkey
.bytes
> servkey
.bytes
) {
3418 ret
= rsaencrypt(s
->rsabuf
, 32, &servkey
);
3420 ret
= rsaencrypt(s
->rsabuf
, servkey
.bytes
, &hostkey
);
3422 ret
= rsaencrypt(s
->rsabuf
, 32, &hostkey
);
3424 ret
= rsaencrypt(s
->rsabuf
, hostkey
.bytes
, &servkey
);
3427 bombout(("SSH-1 public key encryptions failed due to bad formatting"));
3431 logevent("Encrypted session key");
3434 int cipher_chosen
= 0, warn
= 0;
3435 char *cipher_string
= NULL
;
3437 for (i
= 0; !cipher_chosen
&& i
< CIPHER_MAX
; i
++) {
3438 int next_cipher
= conf_get_int_int(ssh
->conf
,
3439 CONF_ssh_cipherlist
, i
);
3440 if (next_cipher
== CIPHER_WARN
) {
3441 /* If/when we choose a cipher, warn about it */
3443 } else if (next_cipher
== CIPHER_AES
) {
3444 /* XXX Probably don't need to mention this. */
3445 logevent("AES not supported in SSH-1, skipping");
3447 switch (next_cipher
) {
3448 case CIPHER_3DES
: s
->cipher_type
= SSH_CIPHER_3DES
;
3449 cipher_string
= "3DES"; break;
3450 case CIPHER_BLOWFISH
: s
->cipher_type
= SSH_CIPHER_BLOWFISH
;
3451 cipher_string
= "Blowfish"; break;
3452 case CIPHER_DES
: s
->cipher_type
= SSH_CIPHER_DES
;
3453 cipher_string
= "single-DES"; break;
3455 if (s
->supported_ciphers_mask
& (1 << s
->cipher_type
))
3459 if (!cipher_chosen
) {
3460 if ((s
->supported_ciphers_mask
& (1 << SSH_CIPHER_3DES
)) == 0)
3461 bombout(("Server violates SSH-1 protocol by not "
3462 "supporting 3DES encryption"));
3464 /* shouldn't happen */
3465 bombout(("No supported ciphers found"));
3469 /* Warn about chosen cipher if necessary. */
3471 ssh_set_frozen(ssh
, 1);
3472 s
->dlgret
= askalg(ssh
->frontend
, "cipher", cipher_string
,
3473 ssh_dialog_callback
, ssh
);
3474 if (s
->dlgret
< 0) {
3478 bombout(("Unexpected data from server while waiting"
3479 " for user response"));
3482 } while (pktin
|| inlen
> 0);
3483 s
->dlgret
= ssh
->user_response
;
3485 ssh_set_frozen(ssh
, 0);
3486 if (s
->dlgret
== 0) {
3487 ssh_disconnect(ssh
, "User aborted at cipher warning", NULL
,
3494 switch (s
->cipher_type
) {
3495 case SSH_CIPHER_3DES
:
3496 logevent("Using 3DES encryption");
3498 case SSH_CIPHER_DES
:
3499 logevent("Using single-DES encryption");
3501 case SSH_CIPHER_BLOWFISH
:
3502 logevent("Using Blowfish encryption");
3506 send_packet(ssh
, SSH1_CMSG_SESSION_KEY
,
3507 PKT_CHAR
, s
->cipher_type
,
3508 PKT_DATA
, cookie
, 8,
3509 PKT_CHAR
, (s
->len
* 8) >> 8, PKT_CHAR
, (s
->len
* 8) & 0xFF,
3510 PKT_DATA
, s
->rsabuf
, s
->len
,
3511 PKT_INT
, ssh
->v1_local_protoflags
, PKT_END
);
3513 logevent("Trying to enable encryption...");
3517 ssh
->cipher
= (s
->cipher_type
== SSH_CIPHER_BLOWFISH ?
&ssh_blowfish_ssh1
:
3518 s
->cipher_type
== SSH_CIPHER_DES ?
&ssh_des
:
3520 ssh
->v1_cipher_ctx
= ssh
->cipher
->make_context();
3521 ssh
->cipher
->sesskey(ssh
->v1_cipher_ctx
, ssh
->session_key
);
3522 logeventf(ssh
, "Initialised %s encryption", ssh
->cipher
->text_name
);
3524 ssh
->crcda_ctx
= crcda_make_context();
3525 logevent("Installing CRC compensation attack detector");
3527 if (servkey
.modulus
) {
3528 sfree(servkey
.modulus
);
3529 servkey
.modulus
= NULL
;
3531 if (servkey
.exponent
) {
3532 sfree(servkey
.exponent
);
3533 servkey
.exponent
= NULL
;
3535 if (hostkey
.modulus
) {
3536 sfree(hostkey
.modulus
);
3537 hostkey
.modulus
= NULL
;
3539 if (hostkey
.exponent
) {
3540 sfree(hostkey
.exponent
);
3541 hostkey
.exponent
= NULL
;
3545 if (pktin
->type
!= SSH1_SMSG_SUCCESS
) {
3546 bombout(("Encryption not successfully enabled"));
3550 logevent("Successfully started encryption");
3552 fflush(stdout
); /* FIXME eh? */
3554 if ((ssh
->username
= get_remote_username(ssh
->conf
)) == NULL
) {
3555 int ret
; /* need not be kept over crReturn */
3556 s
->cur_prompt
= new_prompts(ssh
->frontend
);
3557 s
->cur_prompt
->to_server
= TRUE
;
3558 s
->cur_prompt
->name
= dupstr("SSH login name");
3559 add_prompt(s
->cur_prompt
, dupstr("login as: "), TRUE
);
3560 ret
= get_userpass_input(s
->cur_prompt
, NULL
, 0);
3563 crWaitUntil(!pktin
);
3564 ret
= get_userpass_input(s
->cur_prompt
, in
, inlen
);
3569 * Failed to get a username. Terminate.
3571 free_prompts(s
->cur_prompt
);
3572 ssh_disconnect(ssh
, "No username provided", NULL
, 0, TRUE
);
3575 ssh
->username
= dupstr(s
->cur_prompt
->prompts
[0]->result
);
3576 free_prompts(s
->cur_prompt
);
3579 send_packet(ssh
, SSH1_CMSG_USER
, PKT_STR
, ssh
->username
, PKT_END
);
3581 char *userlog
= dupprintf("Sent username \"%s\"", ssh
->username
);
3583 if (flags
& FLAG_INTERACTIVE
&&
3584 (!((flags
& FLAG_STDERR
) && (flags
& FLAG_VERBOSE
)))) {
3585 c_write_str(ssh
, userlog
);
3586 c_write_str(ssh
, "\r\n");
3594 if ((s
->supported_auths_mask
& (1 << SSH1_AUTH_RSA
)) == 0) {
3595 /* We must not attempt PK auth. Pretend we've already tried it. */
3596 s
->tried_publickey
= s
->tried_agent
= 1;
3598 s
->tried_publickey
= s
->tried_agent
= 0;
3600 s
->tis_auth_refused
= s
->ccard_auth_refused
= 0;
3602 * Load the public half of any configured keyfile for later use.
3604 s
->keyfile
= conf_get_filename(ssh
->conf
, CONF_keyfile
);
3605 if (!filename_is_null(s
->keyfile
)) {
3607 logeventf(ssh
, "Reading private key file \"%.150s\"",
3608 filename_to_str(s
->keyfile
));
3609 keytype
= key_type(s
->keyfile
);
3610 if (keytype
== SSH_KEYTYPE_SSH1
) {
3612 if (rsakey_pubblob(s
->keyfile
,
3613 &s
->publickey_blob
, &s
->publickey_bloblen
,
3614 &s
->publickey_comment
, &error
)) {
3615 s
->publickey_encrypted
= rsakey_encrypted(s
->keyfile
,
3619 logeventf(ssh
, "Unable to load private key (%s)", error
);
3620 msgbuf
= dupprintf("Unable to load private key file "
3621 "\"%.150s\" (%s)\r\n",
3622 filename_to_str(s
->keyfile
),
3624 c_write_str(ssh
, msgbuf
);
3626 s
->publickey_blob
= NULL
;
3630 logeventf(ssh
, "Unable to use this key file (%s)",
3631 key_type_to_str(keytype
));
3632 msgbuf
= dupprintf("Unable to use key file \"%.150s\""
3634 filename_to_str(s
->keyfile
),
3635 key_type_to_str(keytype
));
3636 c_write_str(ssh
, msgbuf
);
3638 s
->publickey_blob
= NULL
;
3641 s
->publickey_blob
= NULL
;
3643 while (pktin
->type
== SSH1_SMSG_FAILURE
) {
3644 s
->pwpkt_type
= SSH1_CMSG_AUTH_PASSWORD
;
3646 if (conf_get_int(ssh
->conf
, CONF_tryagent
) && agent_exists() && !s
->tried_agent
) {
3648 * Attempt RSA authentication using Pageant.
3654 logevent("Pageant is running. Requesting keys.");
3656 /* Request the keys held by the agent. */
3657 PUT_32BIT(s
->request
, 1);
3658 s
->request
[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES
;
3659 if (!agent_query(s
->request
, 5, &r
, &s
->responselen
,
3660 ssh_agent_callback
, ssh
)) {
3664 bombout(("Unexpected data from server while waiting"
3665 " for agent response"));
3668 } while (pktin
|| inlen
> 0);
3669 r
= ssh
->agent_response
;
3670 s
->responselen
= ssh
->agent_response_len
;
3672 s
->response
= (unsigned char *) r
;
3673 if (s
->response
&& s
->responselen
>= 5 &&
3674 s
->response
[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER
) {
3675 s
->p
= s
->response
+ 5;
3676 s
->nkeys
= GET_32BIT(s
->p
);
3678 logeventf(ssh
, "Pageant has %d SSH-1 keys", s
->nkeys
);
3679 for (s
->keyi
= 0; s
->keyi
< s
->nkeys
; s
->keyi
++) {
3680 unsigned char *pkblob
= s
->p
;
3684 do { /* do while (0) to make breaking easy */
3685 n
= ssh1_read_bignum
3686 (s
->p
, s
->responselen
-(s
->p
-s
->response
),
3691 n
= ssh1_read_bignum
3692 (s
->p
, s
->responselen
-(s
->p
-s
->response
),
3697 if (s
->responselen
- (s
->p
-s
->response
) < 4)
3699 s
->commentlen
= GET_32BIT(s
->p
);
3701 if (s
->responselen
- (s
->p
-s
->response
) <
3704 s
->commentp
= (char *)s
->p
;
3705 s
->p
+= s
->commentlen
;
3709 logevent("Pageant key list packet was truncated");
3713 if (s
->publickey_blob
) {
3714 if (!memcmp(pkblob
, s
->publickey_blob
,
3715 s
->publickey_bloblen
)) {
3716 logeventf(ssh
, "Pageant key #%d matches "
3717 "configured key file", s
->keyi
);
3718 s
->tried_publickey
= 1;
3720 /* Skip non-configured key */
3723 logeventf(ssh
, "Trying Pageant key #%d", s
->keyi
);
3724 send_packet(ssh
, SSH1_CMSG_AUTH_RSA
,
3725 PKT_BIGNUM
, s
->key
.modulus
, PKT_END
);
3727 if (pktin
->type
!= SSH1_SMSG_AUTH_RSA_CHALLENGE
) {
3728 logevent("Key refused");
3731 logevent("Received RSA challenge");
3732 if ((s
->challenge
= ssh1_pkt_getmp(pktin
)) == NULL
) {
3733 bombout(("Server's RSA challenge was badly formatted"));
3738 char *agentreq
, *q
, *ret
;
3741 len
= 1 + 4; /* message type, bit count */
3742 len
+= ssh1_bignum_length(s
->key
.exponent
);
3743 len
+= ssh1_bignum_length(s
->key
.modulus
);
3744 len
+= ssh1_bignum_length(s
->challenge
);
3745 len
+= 16; /* session id */
3746 len
+= 4; /* response format */
3747 agentreq
= snewn(4 + len
, char);
3748 PUT_32BIT(agentreq
, len
);
3750 *q
++ = SSH1_AGENTC_RSA_CHALLENGE
;
3751 PUT_32BIT(q
, bignum_bitcount(s
->key
.modulus
));
3753 q
+= ssh1_write_bignum(q
, s
->key
.exponent
);
3754 q
+= ssh1_write_bignum(q
, s
->key
.modulus
);
3755 q
+= ssh1_write_bignum(q
, s
->challenge
);
3756 memcpy(q
, s
->session_id
, 16);
3758 PUT_32BIT(q
, 1); /* response format */
3759 if (!agent_query(agentreq
, len
+ 4, &vret
, &retlen
,
3760 ssh_agent_callback
, ssh
)) {
3765 bombout(("Unexpected data from server"
3766 " while waiting for agent"
3770 } while (pktin
|| inlen
> 0);
3771 vret
= ssh
->agent_response
;
3772 retlen
= ssh
->agent_response_len
;
3777 if (ret
[4] == SSH1_AGENT_RSA_RESPONSE
) {
3778 logevent("Sending Pageant's response");
3779 send_packet(ssh
, SSH1_CMSG_AUTH_RSA_RESPONSE
,
3780 PKT_DATA
, ret
+ 5, 16,
3784 if (pktin
->type
== SSH1_SMSG_SUCCESS
) {
3786 ("Pageant's response accepted");
3787 if (flags
& FLAG_VERBOSE
) {
3788 c_write_str(ssh
, "Authenticated using"
3790 c_write(ssh
, s
->commentp
,
3792 c_write_str(ssh
, "\" from agent\r\n");
3797 ("Pageant's response not accepted");
3800 ("Pageant failed to answer challenge");
3804 logevent("No reply received from Pageant");
3807 freebn(s
->key
.exponent
);
3808 freebn(s
->key
.modulus
);
3809 freebn(s
->challenge
);
3814 if (s
->publickey_blob
&& !s
->tried_publickey
)
3815 logevent("Configured key file not in Pageant");
3817 logevent("Failed to get reply from Pageant");
3822 if (s
->publickey_blob
&& !s
->tried_publickey
) {
3824 * Try public key authentication with the specified
3827 int got_passphrase
; /* need not be kept over crReturn */
3828 if (flags
& FLAG_VERBOSE
)
3829 c_write_str(ssh
, "Trying public key authentication.\r\n");
3830 s
->keyfile
= conf_get_filename(ssh
->conf
, CONF_keyfile
);
3831 logeventf(ssh
, "Trying public key \"%s\"",
3832 filename_to_str(s
->keyfile
));
3833 s
->tried_publickey
= 1;
3834 got_passphrase
= FALSE
;
3835 while (!got_passphrase
) {
3837 * Get a passphrase, if necessary.
3839 char *passphrase
= NULL
; /* only written after crReturn */
3841 if (!s
->publickey_encrypted
) {
3842 if (flags
& FLAG_VERBOSE
)
3843 c_write_str(ssh
, "No passphrase required.\r\n");
3846 int ret
; /* need not be kept over crReturn */
3847 s
->cur_prompt
= new_prompts(ssh
->frontend
);
3848 s
->cur_prompt
->to_server
= FALSE
;
3849 s
->cur_prompt
->name
= dupstr("SSH key passphrase");
3850 add_prompt(s
->cur_prompt
,
3851 dupprintf("Passphrase for key \"%.100s\": ",
3852 s
->publickey_comment
), FALSE
);
3853 ret
= get_userpass_input(s
->cur_prompt
, NULL
, 0);
3856 crWaitUntil(!pktin
);
3857 ret
= get_userpass_input(s
->cur_prompt
, in
, inlen
);
3861 /* Failed to get a passphrase. Terminate. */
3862 free_prompts(s
->cur_prompt
);
3863 ssh_disconnect(ssh
, NULL
, "Unable to authenticate",
3867 passphrase
= dupstr(s
->cur_prompt
->prompts
[0]->result
);
3868 free_prompts(s
->cur_prompt
);
3871 * Try decrypting key with passphrase.
3873 s
->keyfile
= conf_get_filename(ssh
->conf
, CONF_keyfile
);
3874 ret
= loadrsakey(s
->keyfile
, &s
->key
, passphrase
,
3877 smemclr(passphrase
, strlen(passphrase
));
3881 /* Correct passphrase. */
3882 got_passphrase
= TRUE
;
3883 } else if (ret
== 0) {
3884 c_write_str(ssh
, "Couldn't load private key from ");
3885 c_write_str(ssh
, filename_to_str(s
->keyfile
));
3886 c_write_str(ssh
, " (");
3887 c_write_str(ssh
, error
);
3888 c_write_str(ssh
, ").\r\n");
3889 got_passphrase
= FALSE
;
3890 break; /* go and try something else */
3891 } else if (ret
== -1) {
3892 c_write_str(ssh
, "Wrong passphrase.\r\n"); /* FIXME */
3893 got_passphrase
= FALSE
;
3896 assert(0 && "unexpected return from loadrsakey()");
3897 got_passphrase
= FALSE
; /* placate optimisers */
3901 if (got_passphrase
) {
3904 * Send a public key attempt.
3906 send_packet(ssh
, SSH1_CMSG_AUTH_RSA
,
3907 PKT_BIGNUM
, s
->key
.modulus
, PKT_END
);
3910 if (pktin
->type
== SSH1_SMSG_FAILURE
) {
3911 c_write_str(ssh
, "Server refused our public key.\r\n");
3912 continue; /* go and try something else */
3914 if (pktin
->type
!= SSH1_SMSG_AUTH_RSA_CHALLENGE
) {
3915 bombout(("Bizarre response to offer of public key"));
3921 unsigned char buffer
[32];
3922 Bignum challenge
, response
;
3924 if ((challenge
= ssh1_pkt_getmp(pktin
)) == NULL
) {
3925 bombout(("Server's RSA challenge was badly formatted"));
3928 response
= rsadecrypt(challenge
, &s
->key
);
3929 freebn(s
->key
.private_exponent
);/* burn the evidence */
3931 for (i
= 0; i
< 32; i
++) {
3932 buffer
[i
] = bignum_byte(response
, 31 - i
);
3936 MD5Update(&md5c
, buffer
, 32);
3937 MD5Update(&md5c
, s
->session_id
, 16);
3938 MD5Final(buffer
, &md5c
);
3940 send_packet(ssh
, SSH1_CMSG_AUTH_RSA_RESPONSE
,
3941 PKT_DATA
, buffer
, 16, PKT_END
);
3948 if (pktin
->type
== SSH1_SMSG_FAILURE
) {
3949 if (flags
& FLAG_VERBOSE
)
3950 c_write_str(ssh
, "Failed to authenticate with"
3951 " our public key.\r\n");
3952 continue; /* go and try something else */
3953 } else if (pktin
->type
!= SSH1_SMSG_SUCCESS
) {
3954 bombout(("Bizarre response to RSA authentication response"));
3958 break; /* we're through! */
3964 * Otherwise, try various forms of password-like authentication.
3966 s
->cur_prompt
= new_prompts(ssh
->frontend
);
3968 if (conf_get_int(ssh
->conf
, CONF_try_tis_auth
) &&
3969 (s
->supported_auths_mask
& (1 << SSH1_AUTH_TIS
)) &&
3970 !s
->tis_auth_refused
) {
3971 s
->pwpkt_type
= SSH1_CMSG_AUTH_TIS_RESPONSE
;
3972 logevent("Requested TIS authentication");
3973 send_packet(ssh
, SSH1_CMSG_AUTH_TIS
, PKT_END
);
3975 if (pktin
->type
!= SSH1_SMSG_AUTH_TIS_CHALLENGE
) {
3976 logevent("TIS authentication declined");
3977 if (flags
& FLAG_INTERACTIVE
)
3978 c_write_str(ssh
, "TIS authentication refused.\r\n");
3979 s
->tis_auth_refused
= 1;
3984 char *instr_suf
, *prompt
;
3986 ssh_pkt_getstring(pktin
, &challenge
, &challengelen
);
3988 bombout(("TIS challenge packet was badly formed"));
3991 logevent("Received TIS challenge");
3992 s
->cur_prompt
->to_server
= TRUE
;
3993 s
->cur_prompt
->name
= dupstr("SSH TIS authentication");
3994 /* Prompt heuristic comes from OpenSSH */
3995 if (memchr(challenge
, '\n', challengelen
)) {
3996 instr_suf
= dupstr("");
3997 prompt
= dupprintf("%.*s", challengelen
, challenge
);
3999 instr_suf
= dupprintf("%.*s", challengelen
, challenge
);
4000 prompt
= dupstr("Response: ");
4002 s
->cur_prompt
->instruction
=
4003 dupprintf("Using TIS authentication.%s%s",
4004 (*instr_suf
) ?
"\n" : "",
4006 s
->cur_prompt
->instr_reqd
= TRUE
;
4007 add_prompt(s
->cur_prompt
, prompt
, FALSE
);
4011 if (conf_get_int(ssh
->conf
, CONF_try_tis_auth
) &&
4012 (s
->supported_auths_mask
& (1 << SSH1_AUTH_CCARD
)) &&
4013 !s
->ccard_auth_refused
) {
4014 s
->pwpkt_type
= SSH1_CMSG_AUTH_CCARD_RESPONSE
;
4015 logevent("Requested CryptoCard authentication");
4016 send_packet(ssh
, SSH1_CMSG_AUTH_CCARD
, PKT_END
);
4018 if (pktin
->type
!= SSH1_SMSG_AUTH_CCARD_CHALLENGE
) {
4019 logevent("CryptoCard authentication declined");
4020 c_write_str(ssh
, "CryptoCard authentication refused.\r\n");
4021 s
->ccard_auth_refused
= 1;
4026 char *instr_suf
, *prompt
;
4028 ssh_pkt_getstring(pktin
, &challenge
, &challengelen
);
4030 bombout(("CryptoCard challenge packet was badly formed"));
4033 logevent("Received CryptoCard challenge");
4034 s
->cur_prompt
->to_server
= TRUE
;
4035 s
->cur_prompt
->name
= dupstr("SSH CryptoCard authentication");
4036 s
->cur_prompt
->name_reqd
= FALSE
;
4037 /* Prompt heuristic comes from OpenSSH */
4038 if (memchr(challenge
, '\n', challengelen
)) {
4039 instr_suf
= dupstr("");
4040 prompt
= dupprintf("%.*s", challengelen
, challenge
);
4042 instr_suf
= dupprintf("%.*s", challengelen
, challenge
);
4043 prompt
= dupstr("Response: ");
4045 s
->cur_prompt
->instruction
=
4046 dupprintf("Using CryptoCard authentication.%s%s",
4047 (*instr_suf
) ?
"\n" : "",
4049 s
->cur_prompt
->instr_reqd
= TRUE
;
4050 add_prompt(s
->cur_prompt
, prompt
, FALSE
);
4054 if (s
->pwpkt_type
== SSH1_CMSG_AUTH_PASSWORD
) {
4055 if ((s
->supported_auths_mask
& (1 << SSH1_AUTH_PASSWORD
)) == 0) {
4056 bombout(("No supported authentication methods available"));
4059 s
->cur_prompt
->to_server
= TRUE
;
4060 s
->cur_prompt
->name
= dupstr("SSH password");
4061 add_prompt(s
->cur_prompt
, dupprintf("%s@%s's password: ",
4062 ssh
->username
, ssh
->savedhost
),
4067 * Show password prompt, having first obtained it via a TIS
4068 * or CryptoCard exchange if we're doing TIS or CryptoCard
4072 int ret
; /* need not be kept over crReturn */
4073 ret
= get_userpass_input(s
->cur_prompt
, NULL
, 0);
4076 crWaitUntil(!pktin
);
4077 ret
= get_userpass_input(s
->cur_prompt
, in
, inlen
);
4082 * Failed to get a password (for example
4083 * because one was supplied on the command line
4084 * which has already failed to work). Terminate.
4086 free_prompts(s
->cur_prompt
);
4087 ssh_disconnect(ssh
, NULL
, "Unable to authenticate", 0, TRUE
);
4092 if (s
->pwpkt_type
== SSH1_CMSG_AUTH_PASSWORD
) {
4094 * Defence against traffic analysis: we send a
4095 * whole bunch of packets containing strings of
4096 * different lengths. One of these strings is the
4097 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
4098 * The others are all random data in
4099 * SSH1_MSG_IGNORE packets. This way a passive
4100 * listener can't tell which is the password, and
4101 * hence can't deduce the password length.
4103 * Anybody with a password length greater than 16
4104 * bytes is going to have enough entropy in their
4105 * password that a listener won't find it _that_
4106 * much help to know how long it is. So what we'll
4109 * - if password length < 16, we send 15 packets
4110 * containing string lengths 1 through 15
4112 * - otherwise, we let N be the nearest multiple
4113 * of 8 below the password length, and send 8
4114 * packets containing string lengths N through
4115 * N+7. This won't obscure the order of
4116 * magnitude of the password length, but it will
4117 * introduce a bit of extra uncertainty.
4119 * A few servers can't deal with SSH1_MSG_IGNORE, at
4120 * least in this context. For these servers, we need
4121 * an alternative defence. We make use of the fact
4122 * that the password is interpreted as a C string:
4123 * so we can append a NUL, then some random data.
4125 * A few servers can deal with neither SSH1_MSG_IGNORE
4126 * here _nor_ a padded password string.
4127 * For these servers we are left with no defences
4128 * against password length sniffing.
4130 if (!(ssh
->remote_bugs
& BUG_CHOKES_ON_SSH1_IGNORE
) &&
4131 !(ssh
->remote_bugs
& BUG_NEEDS_SSH1_PLAIN_PASSWORD
)) {
4133 * The server can deal with SSH1_MSG_IGNORE, so
4134 * we can use the primary defence.
4136 int bottom
, top
, pwlen
, i
;
4139 pwlen
= strlen(s
->cur_prompt
->prompts
[0]->result
);
4141 bottom
= 0; /* zero length passwords are OK! :-) */
4144 bottom
= pwlen
& ~7;
4148 assert(pwlen
>= bottom
&& pwlen
<= top
);
4150 randomstr
= snewn(top
+ 1, char);
4152 for (i
= bottom
; i
<= top
; i
++) {
4154 defer_packet(ssh
, s
->pwpkt_type
,
4155 PKTT_PASSWORD
, PKT_STR
,
4156 s
->cur_prompt
->prompts
[0]->result
,
4157 PKTT_OTHER
, PKT_END
);
4159 for (j
= 0; j
< i
; j
++) {
4161 randomstr
[j
] = random_byte();
4162 } while (randomstr
[j
] == '\0');
4164 randomstr
[i
] = '\0';
4165 defer_packet(ssh
, SSH1_MSG_IGNORE
,
4166 PKT_STR
, randomstr
, PKT_END
);
4169 logevent("Sending password with camouflage packets");
4170 ssh_pkt_defersend(ssh
);
4173 else if (!(ssh
->remote_bugs
& BUG_NEEDS_SSH1_PLAIN_PASSWORD
)) {
4175 * The server can't deal with SSH1_MSG_IGNORE
4176 * but can deal with padded passwords, so we
4177 * can use the secondary defence.
4183 len
= strlen(s
->cur_prompt
->prompts
[0]->result
);
4184 if (len
< sizeof(string
)) {
4186 strcpy(string
, s
->cur_prompt
->prompts
[0]->result
);
4187 len
++; /* cover the zero byte */
4188 while (len
< sizeof(string
)) {
4189 string
[len
++] = (char) random_byte();
4192 ss
= s
->cur_prompt
->prompts
[0]->result
;
4194 logevent("Sending length-padded password");
4195 send_packet(ssh
, s
->pwpkt_type
, PKTT_PASSWORD
,
4196 PKT_INT
, len
, PKT_DATA
, ss
, len
,
4197 PKTT_OTHER
, PKT_END
);
4200 * The server is believed unable to cope with
4201 * any of our password camouflage methods.
4204 len
= strlen(s
->cur_prompt
->prompts
[0]->result
);
4205 logevent("Sending unpadded password");
4206 send_packet(ssh
, s
->pwpkt_type
,
4207 PKTT_PASSWORD
, PKT_INT
, len
,
4208 PKT_DATA
, s
->cur_prompt
->prompts
[0]->result
, len
,
4209 PKTT_OTHER
, PKT_END
);
4212 send_packet(ssh
, s
->pwpkt_type
, PKTT_PASSWORD
,
4213 PKT_STR
, s
->cur_prompt
->prompts
[0]->result
,
4214 PKTT_OTHER
, PKT_END
);
4216 logevent("Sent password");
4217 free_prompts(s
->cur_prompt
);
4219 if (pktin
->type
== SSH1_SMSG_FAILURE
) {
4220 if (flags
& FLAG_VERBOSE
)
4221 c_write_str(ssh
, "Access denied\r\n");
4222 logevent("Authentication refused");
4223 } else if (pktin
->type
!= SSH1_SMSG_SUCCESS
) {
4224 bombout(("Strange packet received, type %d", pktin
->type
));
4230 if (s
->publickey_blob
) {
4231 sfree(s
->publickey_blob
);
4232 sfree(s
->publickey_comment
);
4235 logevent("Authentication successful");
4240 static void ssh_channel_try_eof(struct ssh_channel
*c
)
4243 assert(c
->pending_eof
); /* precondition for calling us */
4245 return; /* can't close: not even opened yet */
4246 if (ssh
->version
== 2 && bufchain_size(&c
->v
.v2
.outbuffer
) > 0)
4247 return; /* can't send EOF: pending outgoing data */
4249 c
->pending_eof
= FALSE
; /* we're about to send it */
4250 if (ssh
->version
== 1) {
4251 send_packet(ssh
, SSH1_MSG_CHANNEL_CLOSE
, PKT_INT
, c
->remoteid
,
4253 c
->closes
|= CLOSES_SENT_EOF
;
4255 struct Packet
*pktout
;
4256 pktout
= ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF
);
4257 ssh2_pkt_adduint32(pktout
, c
->remoteid
);
4258 ssh2_pkt_send(ssh
, pktout
);
4259 c
->closes
|= CLOSES_SENT_EOF
;
4260 ssh2_channel_check_close(c
);
4264 void sshfwd_write_eof(struct ssh_channel
*c
)
4268 if (ssh
->state
== SSH_STATE_CLOSED
)
4271 if (c
->closes
& CLOSES_SENT_EOF
)
4274 c
->pending_eof
= TRUE
;
4275 ssh_channel_try_eof(c
);
4278 void sshfwd_unclean_close(struct ssh_channel
*c
)
4281 struct Packet
*pktout
;
4283 if (ssh
->state
== SSH_STATE_CLOSED
)
4286 if (!(c
->closes
& CLOSES_SENT_CLOSE
)) {
4287 pktout
= ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE
);
4288 ssh2_pkt_adduint32(pktout
, c
->remoteid
);
4289 ssh2_pkt_send(ssh
, pktout
);
4290 c
->closes
|= CLOSES_SENT_EOF
| CLOSES_SENT_CLOSE
;
4295 x11_close(c
->u
.x11
.s
);
4298 case CHAN_SOCKDATA_DORMANT
:
4299 pfd_close(c
->u
.pfd
.s
);
4302 c
->type
= CHAN_ZOMBIE
;
4304 ssh2_channel_check_close(c
);
4307 int sshfwd_write(struct ssh_channel
*c
, char *buf
, int len
)
4311 if (ssh
->state
== SSH_STATE_CLOSED
)
4314 if (ssh
->version
== 1) {
4315 send_packet(ssh
, SSH1_MSG_CHANNEL_DATA
,
4316 PKT_INT
, c
->remoteid
,
4317 PKT_INT
, len
, PKTT_DATA
, PKT_DATA
, buf
, len
,
4318 PKTT_OTHER
, PKT_END
);
4320 * In SSH-1 we can return 0 here - implying that forwarded
4321 * connections are never individually throttled - because
4322 * the only circumstance that can cause throttling will be
4323 * the whole SSH connection backing up, in which case
4324 * _everything_ will be throttled as a whole.
4328 ssh2_add_channel_data(c
, buf
, len
);
4329 return ssh2_try_send(c
);
4333 void sshfwd_unthrottle(struct ssh_channel
*c
, int bufsize
)
4338 if (ssh
->state
== SSH_STATE_CLOSED
)
4341 if (ssh
->version
== 1) {
4342 buflimit
= SSH1_BUFFER_LIMIT
;
4344 buflimit
= c
->v
.v2
.locmaxwin
;
4345 ssh2_set_window(c
, bufsize
< buflimit ? buflimit
- bufsize
: 0);
4347 if (c
->throttling_conn
&& bufsize
<= buflimit
) {
4348 c
->throttling_conn
= 0;
4349 ssh_throttle_conn(ssh
, -1);
4353 static void ssh_queueing_handler(Ssh ssh
, struct Packet
*pktin
)
4355 struct queued_handler
*qh
= ssh
->qhead
;
4359 assert(pktin
->type
== qh
->msg1
|| pktin
->type
== qh
->msg2
);
4362 assert(ssh
->packet_dispatch
[qh
->msg1
] == ssh_queueing_handler
);
4363 ssh
->packet_dispatch
[qh
->msg1
] = ssh
->q_saved_handler1
;
4366 assert(ssh
->packet_dispatch
[qh
->msg2
] == ssh_queueing_handler
);
4367 ssh
->packet_dispatch
[qh
->msg2
] = ssh
->q_saved_handler2
;
4371 ssh
->qhead
= qh
->next
;
4373 if (ssh
->qhead
->msg1
> 0) {
4374 ssh
->q_saved_handler1
= ssh
->packet_dispatch
[ssh
->qhead
->msg1
];
4375 ssh
->packet_dispatch
[ssh
->qhead
->msg1
] = ssh_queueing_handler
;
4377 if (ssh
->qhead
->msg2
> 0) {
4378 ssh
->q_saved_handler2
= ssh
->packet_dispatch
[ssh
->qhead
->msg2
];
4379 ssh
->packet_dispatch
[ssh
->qhead
->msg2
] = ssh_queueing_handler
;
4382 ssh
->qhead
= ssh
->qtail
= NULL
;
4385 qh
->handler(ssh
, pktin
, qh
->ctx
);
4390 static void ssh_queue_handler(Ssh ssh
, int msg1
, int msg2
,
4391 chandler_fn_t handler
, void *ctx
)
4393 struct queued_handler
*qh
;
4395 qh
= snew(struct queued_handler
);
4398 qh
->handler
= handler
;
4402 if (ssh
->qtail
== NULL
) {
4406 ssh
->q_saved_handler1
= ssh
->packet_dispatch
[ssh
->qhead
->msg1
];
4407 ssh
->packet_dispatch
[qh
->msg1
] = ssh_queueing_handler
;
4410 ssh
->q_saved_handler2
= ssh
->packet_dispatch
[ssh
->qhead
->msg2
];
4411 ssh
->packet_dispatch
[qh
->msg2
] = ssh_queueing_handler
;
4414 ssh
->qtail
->next
= qh
;
4419 static void ssh_rportfwd_succfail(Ssh ssh
, struct Packet
*pktin
, void *ctx
)
4421 struct ssh_rportfwd
*rpf
, *pf
= (struct ssh_rportfwd
*)ctx
;
4423 if (pktin
->type
== (ssh
->version
== 1 ? SSH1_SMSG_SUCCESS
:
4424 SSH2_MSG_REQUEST_SUCCESS
)) {
4425 logeventf(ssh
, "Remote port forwarding from %s enabled",
4428 logeventf(ssh
, "Remote port forwarding from %s refused",
4431 rpf
= del234(ssh
->rportfwds
, pf
);
4433 pf
->pfrec
->remote
= NULL
;
4438 static void ssh_setup_portfwd(Ssh ssh
, Conf
*conf
)
4440 struct ssh_portfwd
*epf
;
4444 if (!ssh
->portfwds
) {
4445 ssh
->portfwds
= newtree234(ssh_portcmp
);
4448 * Go through the existing port forwardings and tag them
4449 * with status==DESTROY. Any that we want to keep will be
4450 * re-enabled (status==KEEP) as we go through the
4451 * configuration and find out which bits are the same as
4454 struct ssh_portfwd
*epf
;
4456 for (i
= 0; (epf
= index234(ssh
->portfwds
, i
)) != NULL
; i
++)
4457 epf
->status
= DESTROY
;
4460 for (val
= conf_get_str_strs(conf
, CONF_portfwd
, NULL
, &key
);
4462 val
= conf_get_str_strs(conf
, CONF_portfwd
, key
, &key
)) {
4463 char *kp
, *kp2
, *vp
, *vp2
;
4464 char address_family
, type
;
4465 int sport
,dport
,sserv
,dserv
;
4466 char *sports
, *dports
, *saddr
, *host
;
4470 address_family
= 'A';
4472 if (*kp
== 'A' || *kp
== '4' || *kp
== '6')
4473 address_family
= *kp
++;
4474 if (*kp
== 'L' || *kp
== 'R')
4477 if ((kp2
= strchr(kp
, ':')) != NULL
) {
4479 * There's a colon in the middle of the source port
4480 * string, which means that the part before it is
4481 * actually a source address.
4483 saddr
= dupprintf("%.*s", (int)(kp2
- kp
), kp
);
4489 sport
= atoi(sports
);
4493 sport
= net_service_lookup(sports
);
4495 logeventf(ssh
, "Service lookup failed for source"
4496 " port \"%s\"", sports
);
4500 if (type
== 'L' && !strcmp(val
, "D")) {
4501 /* dynamic forwarding */
4508 /* ordinary forwarding */
4510 vp2
= vp
+ strcspn(vp
, ":");
4511 host
= dupprintf("%.*s", (int)(vp2
- vp
), vp
);
4515 dport
= atoi(dports
);
4519 dport
= net_service_lookup(dports
);
4521 logeventf(ssh
, "Service lookup failed for destination"
4522 " port \"%s\"", dports
);
4527 if (sport
&& dport
) {
4528 /* Set up a description of the source port. */
4529 struct ssh_portfwd
*pfrec
, *epfrec
;
4531 pfrec
= snew(struct ssh_portfwd
);
4533 pfrec
->saddr
= saddr
;
4534 pfrec
->sserv
= sserv ?
dupstr(sports
) : NULL
;
4535 pfrec
->sport
= sport
;
4536 pfrec
->daddr
= host
;
4537 pfrec
->dserv
= dserv ?
dupstr(dports
) : NULL
;
4538 pfrec
->dport
= dport
;
4539 pfrec
->local
= NULL
;
4540 pfrec
->remote
= NULL
;
4541 pfrec
->addressfamily
= (address_family
== '4' ? ADDRTYPE_IPV4
:
4542 address_family
== '6' ? ADDRTYPE_IPV6
:
4545 epfrec
= add234(ssh
->portfwds
, pfrec
);
4546 if (epfrec
!= pfrec
) {
4547 if (epfrec
->status
== DESTROY
) {
4549 * We already have a port forwarding up and running
4550 * with precisely these parameters. Hence, no need
4551 * to do anything; simply re-tag the existing one
4554 epfrec
->status
= KEEP
;
4557 * Anything else indicates that there was a duplicate
4558 * in our input, which we'll silently ignore.
4560 free_portfwd(pfrec
);
4562 pfrec
->status
= CREATE
;
4571 * Now go through and destroy any port forwardings which were
4574 for (i
= 0; (epf
= index234(ssh
->portfwds
, i
)) != NULL
; i
++)
4575 if (epf
->status
== DESTROY
) {
4578 message
= dupprintf("%s port forwarding from %s%s%d",
4579 epf
->type
== 'L' ?
"local" :
4580 epf
->type
== 'R' ?
"remote" : "dynamic",
4581 epf
->saddr ? epf
->saddr
: "",
4582 epf
->saddr ?
":" : "",
4585 if (epf
->type
!= 'D') {
4586 char *msg2
= dupprintf("%s to %s:%d", message
,
4587 epf
->daddr
, epf
->dport
);
4592 logeventf(ssh
, "Cancelling %s", message
);
4595 /* epf->remote or epf->local may be NULL if setting up a
4596 * forwarding failed. */
4598 struct ssh_rportfwd
*rpf
= epf
->remote
;
4599 struct Packet
*pktout
;
4602 * Cancel the port forwarding at the server
4605 if (ssh
->version
== 1) {
4607 * We cannot cancel listening ports on the
4608 * server side in SSH-1! There's no message
4609 * to support it. Instead, we simply remove
4610 * the rportfwd record from the local end
4611 * so that any connections the server tries
4612 * to make on it are rejected.
4615 pktout
= ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST
);
4616 ssh2_pkt_addstring(pktout
, "cancel-tcpip-forward");
4617 ssh2_pkt_addbool(pktout
, 0);/* _don't_ want reply */
4619 ssh2_pkt_addstring(pktout
, epf
->saddr
);
4620 } else if (conf_get_int(conf
, CONF_rport_acceptall
)) {
4621 /* XXX: rport_acceptall may not represent
4622 * what was used to open the original connection,
4623 * since it's reconfigurable. */
4624 ssh2_pkt_addstring(pktout
, "0.0.0.0");
4626 ssh2_pkt_addstring(pktout
, "127.0.0.1");
4628 ssh2_pkt_adduint32(pktout
, epf
->sport
);
4629 ssh2_pkt_send(ssh
, pktout
);
4632 del234(ssh
->rportfwds
, rpf
);
4634 } else if (epf
->local
) {
4635 pfd_terminate(epf
->local
);
4638 delpos234(ssh
->portfwds
, i
);
4640 i
--; /* so we don't skip one in the list */
4644 * And finally, set up any new port forwardings (status==CREATE).
4646 for (i
= 0; (epf
= index234(ssh
->portfwds
, i
)) != NULL
; i
++)
4647 if (epf
->status
== CREATE
) {
4648 char *sportdesc
, *dportdesc
;
4649 sportdesc
= dupprintf("%s%s%s%s%d%s",
4650 epf
->saddr ? epf
->saddr
: "",
4651 epf
->saddr ?
":" : "",
4652 epf
->sserv ? epf
->sserv
: "",
4653 epf
->sserv ?
"(" : "",
4655 epf
->sserv ?
")" : "");
4656 if (epf
->type
== 'D') {
4659 dportdesc
= dupprintf("%s:%s%s%d%s",
4661 epf
->dserv ? epf
->dserv
: "",
4662 epf
->dserv ?
"(" : "",
4664 epf
->dserv ?
")" : "");
4667 if (epf
->type
== 'L') {
4668 const char *err
= pfd_addforward(epf
->daddr
, epf
->dport
,
4669 epf
->saddr
, epf
->sport
,
4672 epf
->addressfamily
);
4674 logeventf(ssh
, "Local %sport %s forwarding to %s%s%s",
4675 epf
->addressfamily
== ADDRTYPE_IPV4 ?
"IPv4 " :
4676 epf
->addressfamily
== ADDRTYPE_IPV6 ?
"IPv6 " : "",
4677 sportdesc
, dportdesc
,
4678 err ?
" failed: " : "", err ? err
: "");
4679 } else if (epf
->type
== 'D') {
4680 const char *err
= pfd_addforward(NULL
, -1,
4681 epf
->saddr
, epf
->sport
,
4684 epf
->addressfamily
);
4686 logeventf(ssh
, "Local %sport %s SOCKS dynamic forwarding%s%s",
4687 epf
->addressfamily
== ADDRTYPE_IPV4 ?
"IPv4 " :
4688 epf
->addressfamily
== ADDRTYPE_IPV6 ?
"IPv6 " : "",
4690 err ?
" failed: " : "", err ? err
: "");
4692 struct ssh_rportfwd
*pf
;
4695 * Ensure the remote port forwardings tree exists.
4697 if (!ssh
->rportfwds
) {
4698 if (ssh
->version
== 1)
4699 ssh
->rportfwds
= newtree234(ssh_rportcmp_ssh1
);
4701 ssh
->rportfwds
= newtree234(ssh_rportcmp_ssh2
);
4704 pf
= snew(struct ssh_rportfwd
);
4705 strncpy(pf
->dhost
, epf
->daddr
, lenof(pf
->dhost
)-1);
4706 pf
->dhost
[lenof(pf
->dhost
)-1] = '\0';
4707 pf
->dport
= epf
->dport
;
4708 pf
->sport
= epf
->sport
;
4709 if (add234(ssh
->rportfwds
, pf
) != pf
) {
4710 logeventf(ssh
, "Duplicate remote port forwarding to %s:%d",
4711 epf
->daddr
, epf
->dport
);
4714 logeventf(ssh
, "Requesting remote port %s"
4715 " forward to %s", sportdesc
, dportdesc
);
4717 pf
->sportdesc
= sportdesc
;
4722 if (ssh
->version
== 1) {
4723 send_packet(ssh
, SSH1_CMSG_PORT_FORWARD_REQUEST
,
4724 PKT_INT
, epf
->sport
,
4725 PKT_STR
, epf
->daddr
,
4726 PKT_INT
, epf
->dport
,
4728 ssh_queue_handler(ssh
, SSH1_SMSG_SUCCESS
,
4730 ssh_rportfwd_succfail
, pf
);
4732 struct Packet
*pktout
;
4733 pktout
= ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST
);
4734 ssh2_pkt_addstring(pktout
, "tcpip-forward");
4735 ssh2_pkt_addbool(pktout
, 1);/* want reply */
4737 ssh2_pkt_addstring(pktout
, epf
->saddr
);
4738 } else if (conf_get_int(conf
, CONF_rport_acceptall
)) {
4739 ssh2_pkt_addstring(pktout
, "0.0.0.0");
4741 ssh2_pkt_addstring(pktout
, "127.0.0.1");
4743 ssh2_pkt_adduint32(pktout
, epf
->sport
);
4744 ssh2_pkt_send(ssh
, pktout
);
4746 ssh_queue_handler(ssh
, SSH2_MSG_REQUEST_SUCCESS
,
4747 SSH2_MSG_REQUEST_FAILURE
,
4748 ssh_rportfwd_succfail
, pf
);
4757 static void ssh1_smsg_stdout_stderr_data(Ssh ssh
, struct Packet
*pktin
)
4760 int stringlen
, bufsize
;
4762 ssh_pkt_getstring(pktin
, &string
, &stringlen
);
4763 if (string
== NULL
) {
4764 bombout(("Incoming terminal data packet was badly formed"));
4768 bufsize
= from_backend(ssh
->frontend
, pktin
->type
== SSH1_SMSG_STDERR_DATA
,
4770 if (!ssh
->v1_stdout_throttling
&& bufsize
> SSH1_BUFFER_LIMIT
) {
4771 ssh
->v1_stdout_throttling
= 1;
4772 ssh_throttle_conn(ssh
, +1);
4776 static void ssh1_smsg_x11_open(Ssh ssh
, struct Packet
*pktin
)
4778 /* Remote side is trying to open a channel to talk to our
4779 * X-Server. Give them back a local channel number. */
4780 struct ssh_channel
*c
;
4781 int remoteid
= ssh_pkt_getuint32(pktin
);
4783 logevent("Received X11 connect request");
4784 /* Refuse if X11 forwarding is disabled. */
4785 if (!ssh
->X11_fwd_enabled
) {
4786 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_FAILURE
,
4787 PKT_INT
, remoteid
, PKT_END
);
4788 logevent("Rejected X11 connect request");
4790 c
= snew(struct ssh_channel
);
4793 if (x11_init(&c
->u
.x11
.s
, ssh
->x11disp
, c
,
4794 NULL
, -1, ssh
->conf
) != NULL
) {
4795 logevent("Opening X11 forward connection failed");
4797 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_FAILURE
,
4798 PKT_INT
, remoteid
, PKT_END
);
4801 ("Opening X11 forward connection succeeded");
4802 c
->remoteid
= remoteid
;
4803 c
->halfopen
= FALSE
;
4804 c
->localid
= alloc_channel_id(ssh
);
4806 c
->pending_eof
= FALSE
;
4807 c
->throttling_conn
= 0;
4808 c
->type
= CHAN_X11
; /* identify channel type */
4809 add234(ssh
->channels
, c
);
4810 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
,
4811 PKT_INT
, c
->remoteid
, PKT_INT
,
4812 c
->localid
, PKT_END
);
4813 logevent("Opened X11 forward channel");
4818 static void ssh1_smsg_agent_open(Ssh ssh
, struct Packet
*pktin
)
4820 /* Remote side is trying to open a channel to talk to our
4821 * agent. Give them back a local channel number. */
4822 struct ssh_channel
*c
;
4823 int remoteid
= ssh_pkt_getuint32(pktin
);
4825 /* Refuse if agent forwarding is disabled. */
4826 if (!ssh
->agentfwd_enabled
) {
4827 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_FAILURE
,
4828 PKT_INT
, remoteid
, PKT_END
);
4830 c
= snew(struct ssh_channel
);
4832 c
->remoteid
= remoteid
;
4833 c
->halfopen
= FALSE
;
4834 c
->localid
= alloc_channel_id(ssh
);
4836 c
->pending_eof
= FALSE
;
4837 c
->throttling_conn
= 0;
4838 c
->type
= CHAN_AGENT
; /* identify channel type */
4839 c
->u
.a
.lensofar
= 0;
4840 c
->u
.a
.message
= NULL
;
4841 add234(ssh
->channels
, c
);
4842 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
,
4843 PKT_INT
, c
->remoteid
, PKT_INT
, c
->localid
,
4848 static void ssh1_msg_port_open(Ssh ssh
, struct Packet
*pktin
)
4850 /* Remote side is trying to open a channel to talk to a
4851 * forwarded port. Give them back a local channel number. */
4852 struct ssh_channel
*c
;
4853 struct ssh_rportfwd pf
, *pfp
;
4858 c
= snew(struct ssh_channel
);
4861 remoteid
= ssh_pkt_getuint32(pktin
);
4862 ssh_pkt_getstring(pktin
, &host
, &hostsize
);
4863 port
= ssh_pkt_getuint32(pktin
);
4865 if (hostsize
>= lenof(pf
.dhost
))
4866 hostsize
= lenof(pf
.dhost
)-1;
4867 memcpy(pf
.dhost
, host
, hostsize
);
4868 pf
.dhost
[hostsize
] = '\0';
4870 pfp
= find234(ssh
->rportfwds
, &pf
, NULL
);
4873 logeventf(ssh
, "Rejected remote port open request for %s:%d",
4875 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_FAILURE
,
4876 PKT_INT
, remoteid
, PKT_END
);
4878 logeventf(ssh
, "Received remote port open request for %s:%d",
4880 e
= pfd_newconnect(&c
->u
.pfd
.s
, pf
.dhost
, port
,
4881 c
, ssh
->conf
, pfp
->pfrec
->addressfamily
);
4883 logeventf(ssh
, "Port open failed: %s", e
);
4885 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_FAILURE
,
4886 PKT_INT
, remoteid
, PKT_END
);
4888 c
->remoteid
= remoteid
;
4889 c
->halfopen
= FALSE
;
4890 c
->localid
= alloc_channel_id(ssh
);
4892 c
->pending_eof
= FALSE
;
4893 c
->throttling_conn
= 0;
4894 c
->type
= CHAN_SOCKDATA
; /* identify channel type */
4895 add234(ssh
->channels
, c
);
4896 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
,
4897 PKT_INT
, c
->remoteid
, PKT_INT
,
4898 c
->localid
, PKT_END
);
4899 logevent("Forwarded port opened successfully");
4904 static void ssh1_msg_channel_open_confirmation(Ssh ssh
, struct Packet
*pktin
)
4906 unsigned int remoteid
= ssh_pkt_getuint32(pktin
);
4907 unsigned int localid
= ssh_pkt_getuint32(pktin
);
4908 struct ssh_channel
*c
;
4910 c
= find234(ssh
->channels
, &remoteid
, ssh_channelfind
);
4911 if (c
&& c
->type
== CHAN_SOCKDATA_DORMANT
) {
4912 c
->remoteid
= localid
;
4913 c
->halfopen
= FALSE
;
4914 c
->type
= CHAN_SOCKDATA
;
4915 c
->throttling_conn
= 0;
4916 pfd_confirm(c
->u
.pfd
.s
);
4919 if (c
&& c
->pending_eof
) {
4921 * We have a pending close on this channel,
4922 * which we decided on before the server acked
4923 * the channel open. So now we know the
4924 * remoteid, we can close it again.
4926 ssh_channel_try_eof(c
);
4930 static void ssh1_msg_channel_open_failure(Ssh ssh
, struct Packet
*pktin
)
4932 unsigned int remoteid
= ssh_pkt_getuint32(pktin
);
4933 struct ssh_channel
*c
;
4935 c
= find234(ssh
->channels
, &remoteid
, ssh_channelfind
);
4936 if (c
&& c
->type
== CHAN_SOCKDATA_DORMANT
) {
4937 logevent("Forwarded connection refused by server");
4938 pfd_close(c
->u
.pfd
.s
);
4939 del234(ssh
->channels
, c
);
4944 static void ssh1_msg_channel_close(Ssh ssh
, struct Packet
*pktin
)
4946 /* Remote side closes a channel. */
4947 unsigned i
= ssh_pkt_getuint32(pktin
);
4948 struct ssh_channel
*c
;
4949 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
4950 if (c
&& !c
->halfopen
) {
4952 if (pktin
->type
== SSH1_MSG_CHANNEL_CLOSE
&&
4953 !(c
->closes
& CLOSES_RCVD_EOF
)) {
4955 * Received CHANNEL_CLOSE, which we translate into
4958 int send_close
= FALSE
;
4960 c
->closes
|= CLOSES_RCVD_EOF
;
4965 x11_send_eof(c
->u
.x11
.s
);
4971 pfd_send_eof(c
->u
.pfd
.s
);
4980 if (send_close
&& !(c
->closes
& CLOSES_SENT_EOF
)) {
4981 send_packet(ssh
, SSH1_MSG_CHANNEL_CLOSE
, PKT_INT
, c
->remoteid
,
4983 c
->closes
|= CLOSES_SENT_EOF
;
4987 if (pktin
->type
== SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION
&&
4988 !(c
->closes
& CLOSES_RCVD_CLOSE
)) {
4990 if (!(c
->closes
& CLOSES_SENT_EOF
)) {
4991 bombout(("Received CHANNEL_CLOSE_CONFIRMATION for channel %d"
4992 " for which we never sent CHANNEL_CLOSE\n", i
));
4995 c
->closes
|= CLOSES_RCVD_CLOSE
;
4998 if (!((CLOSES_SENT_EOF
| CLOSES_RCVD_EOF
) & ~c
->closes
) &&
4999 !(c
->closes
& CLOSES_SENT_CLOSE
)) {
5000 send_packet(ssh
, SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION
,
5001 PKT_INT
, c
->remoteid
, PKT_END
);
5002 c
->closes
|= CLOSES_SENT_CLOSE
;
5005 if (!((CLOSES_SENT_CLOSE
| CLOSES_RCVD_CLOSE
) & ~c
->closes
))
5006 ssh_channel_destroy(c
);
5008 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
5009 pktin
->type
== SSH1_MSG_CHANNEL_CLOSE ?
"" :
5010 "_CONFIRMATION", c ?
"half-open" : "nonexistent",
5015 static void ssh1_msg_channel_data(Ssh ssh
, struct Packet
*pktin
)
5017 /* Data sent down one of our channels. */
5018 int i
= ssh_pkt_getuint32(pktin
);
5021 struct ssh_channel
*c
;
5023 ssh_pkt_getstring(pktin
, &p
, &len
);
5025 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5030 bufsize
= x11_send(c
->u
.x11
.s
, p
, len
);
5033 bufsize
= pfd_send(c
->u
.pfd
.s
, p
, len
);
5036 /* Data for an agent message. Buffer it. */
5038 if (c
->u
.a
.lensofar
< 4) {
5039 unsigned int l
= min(4 - c
->u
.a
.lensofar
, (unsigned)len
);
5040 memcpy(c
->u
.a
.msglen
+ c
->u
.a
.lensofar
, p
,
5044 c
->u
.a
.lensofar
+= l
;
5046 if (c
->u
.a
.lensofar
== 4) {
5048 4 + GET_32BIT(c
->u
.a
.msglen
);
5049 c
->u
.a
.message
= snewn(c
->u
.a
.totallen
,
5051 memcpy(c
->u
.a
.message
, c
->u
.a
.msglen
, 4);
5053 if (c
->u
.a
.lensofar
>= 4 && len
> 0) {
5055 min(c
->u
.a
.totallen
- c
->u
.a
.lensofar
,
5057 memcpy(c
->u
.a
.message
+ c
->u
.a
.lensofar
, p
,
5061 c
->u
.a
.lensofar
+= l
;
5063 if (c
->u
.a
.lensofar
== c
->u
.a
.totallen
) {
5066 if (agent_query(c
->u
.a
.message
,
5069 ssh_agentf_callback
, c
))
5070 ssh_agentf_callback(c
, reply
, replylen
);
5071 sfree(c
->u
.a
.message
);
5072 c
->u
.a
.lensofar
= 0;
5075 bufsize
= 0; /* agent channels never back up */
5078 if (!c
->throttling_conn
&& bufsize
> SSH1_BUFFER_LIMIT
) {
5079 c
->throttling_conn
= 1;
5080 ssh_throttle_conn(ssh
, +1);
5085 static void ssh1_smsg_exit_status(Ssh ssh
, struct Packet
*pktin
)
5087 ssh
->exitcode
= ssh_pkt_getuint32(pktin
);
5088 logeventf(ssh
, "Server sent command exit status %d", ssh
->exitcode
);
5089 send_packet(ssh
, SSH1_CMSG_EXIT_CONFIRMATION
, PKT_END
);
5091 * In case `helpful' firewalls or proxies tack
5092 * extra human-readable text on the end of the
5093 * session which we might mistake for another
5094 * encrypted packet, we close the session once
5095 * we've sent EXIT_CONFIRMATION.
5097 ssh_disconnect(ssh
, NULL
, NULL
, 0, TRUE
);
5100 /* Helper function to deal with sending tty modes for REQUEST_PTY */
5101 static void ssh1_send_ttymode(void *data
, char *mode
, char *val
)
5103 struct Packet
*pktout
= (struct Packet
*)data
;
5105 unsigned int arg
= 0;
5106 while (strcmp(mode
, ssh_ttymodes
[i
].mode
) != 0) i
++;
5107 if (i
== lenof(ssh_ttymodes
)) return;
5108 switch (ssh_ttymodes
[i
].type
) {
5110 arg
= ssh_tty_parse_specchar(val
);
5113 arg
= ssh_tty_parse_boolean(val
);
5116 ssh2_pkt_addbyte(pktout
, ssh_ttymodes
[i
].opcode
);
5117 ssh2_pkt_addbyte(pktout
, arg
);
5121 static void do_ssh1_connection(Ssh ssh
, unsigned char *in
, int inlen
,
5122 struct Packet
*pktin
)
5124 crBegin(ssh
->do_ssh1_connection_crstate
);
5126 ssh
->packet_dispatch
[SSH1_SMSG_STDOUT_DATA
] =
5127 ssh
->packet_dispatch
[SSH1_SMSG_STDERR_DATA
] =
5128 ssh1_smsg_stdout_stderr_data
;
5130 ssh
->packet_dispatch
[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
] =
5131 ssh1_msg_channel_open_confirmation
;
5132 ssh
->packet_dispatch
[SSH1_MSG_CHANNEL_OPEN_FAILURE
] =
5133 ssh1_msg_channel_open_failure
;
5134 ssh
->packet_dispatch
[SSH1_MSG_CHANNEL_CLOSE
] =
5135 ssh
->packet_dispatch
[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION
] =
5136 ssh1_msg_channel_close
;
5137 ssh
->packet_dispatch
[SSH1_MSG_CHANNEL_DATA
] = ssh1_msg_channel_data
;
5138 ssh
->packet_dispatch
[SSH1_SMSG_EXIT_STATUS
] = ssh1_smsg_exit_status
;
5140 if (conf_get_int(ssh
->conf
, CONF_agentfwd
) && agent_exists()) {
5141 logevent("Requesting agent forwarding");
5142 send_packet(ssh
, SSH1_CMSG_AGENT_REQUEST_FORWARDING
, PKT_END
);
5146 if (pktin
->type
!= SSH1_SMSG_SUCCESS
5147 && pktin
->type
!= SSH1_SMSG_FAILURE
) {
5148 bombout(("Protocol confusion"));
5150 } else if (pktin
->type
== SSH1_SMSG_FAILURE
) {
5151 logevent("Agent forwarding refused");
5153 logevent("Agent forwarding enabled");
5154 ssh
->agentfwd_enabled
= TRUE
;
5155 ssh
->packet_dispatch
[SSH1_SMSG_AGENT_OPEN
] = ssh1_smsg_agent_open
;
5159 if (conf_get_int(ssh
->conf
, CONF_x11_forward
) &&
5160 (ssh
->x11disp
= x11_setup_display(conf_get_str(ssh
->conf
, CONF_x11_display
),
5161 conf_get_int(ssh
->conf
, CONF_x11_auth
), ssh
->conf
))) {
5162 logevent("Requesting X11 forwarding");
5164 * Note that while we blank the X authentication data here, we don't
5165 * take any special action to blank the start of an X11 channel,
5166 * so using MIT-MAGIC-COOKIE-1 and actually opening an X connection
5167 * without having session blanking enabled is likely to leak your
5168 * cookie into the log.
5170 if (ssh
->v1_local_protoflags
& SSH1_PROTOFLAG_SCREEN_NUMBER
) {
5171 send_packet(ssh
, SSH1_CMSG_X11_REQUEST_FORWARDING
,
5172 PKT_STR
, ssh
->x11disp
->remoteauthprotoname
,
5174 PKT_STR
, ssh
->x11disp
->remoteauthdatastring
,
5176 PKT_INT
, ssh
->x11disp
->screennum
,
5179 send_packet(ssh
, SSH1_CMSG_X11_REQUEST_FORWARDING
,
5180 PKT_STR
, ssh
->x11disp
->remoteauthprotoname
,
5182 PKT_STR
, ssh
->x11disp
->remoteauthdatastring
,
5189 if (pktin
->type
!= SSH1_SMSG_SUCCESS
5190 && pktin
->type
!= SSH1_SMSG_FAILURE
) {
5191 bombout(("Protocol confusion"));
5193 } else if (pktin
->type
== SSH1_SMSG_FAILURE
) {
5194 logevent("X11 forwarding refused");
5196 logevent("X11 forwarding enabled");
5197 ssh
->X11_fwd_enabled
= TRUE
;
5198 ssh
->packet_dispatch
[SSH1_SMSG_X11_OPEN
] = ssh1_smsg_x11_open
;
5202 ssh_setup_portfwd(ssh
, ssh
->conf
);
5203 ssh
->packet_dispatch
[SSH1_MSG_PORT_OPEN
] = ssh1_msg_port_open
;
5205 if (!conf_get_int(ssh
->conf
, CONF_nopty
)) {
5207 /* Unpick the terminal-speed string. */
5208 /* XXX perhaps we should allow no speeds to be sent. */
5209 ssh
->ospeed
= 38400; ssh
->ispeed
= 38400; /* last-resort defaults */
5210 sscanf(conf_get_str(ssh
->conf
, CONF_termspeed
), "%d,%d", &ssh
->ospeed
, &ssh
->ispeed
);
5211 /* Send the pty request. */
5212 pkt
= ssh1_pkt_init(SSH1_CMSG_REQUEST_PTY
);
5213 ssh_pkt_addstring(pkt
, conf_get_str(ssh
->conf
, CONF_termtype
));
5214 ssh_pkt_adduint32(pkt
, ssh
->term_height
);
5215 ssh_pkt_adduint32(pkt
, ssh
->term_width
);
5216 ssh_pkt_adduint32(pkt
, 0); /* width in pixels */
5217 ssh_pkt_adduint32(pkt
, 0); /* height in pixels */
5218 parse_ttymodes(ssh
, ssh1_send_ttymode
, (void *)pkt
);
5219 ssh_pkt_addbyte(pkt
, SSH1_TTY_OP_ISPEED
);
5220 ssh_pkt_adduint32(pkt
, ssh
->ispeed
);
5221 ssh_pkt_addbyte(pkt
, SSH1_TTY_OP_OSPEED
);
5222 ssh_pkt_adduint32(pkt
, ssh
->ospeed
);
5223 ssh_pkt_addbyte(pkt
, SSH_TTY_OP_END
);
5225 ssh
->state
= SSH_STATE_INTERMED
;
5229 if (pktin
->type
!= SSH1_SMSG_SUCCESS
5230 && pktin
->type
!= SSH1_SMSG_FAILURE
) {
5231 bombout(("Protocol confusion"));
5233 } else if (pktin
->type
== SSH1_SMSG_FAILURE
) {
5234 c_write_str(ssh
, "Server refused to allocate pty\r\n");
5235 ssh
->editing
= ssh
->echoing
= 1;
5237 logeventf(ssh
, "Allocated pty (ospeed %dbps, ispeed %dbps)",
5238 ssh
->ospeed
, ssh
->ispeed
);
5239 ssh
->got_pty
= TRUE
;
5242 ssh
->editing
= ssh
->echoing
= 1;
5245 if (conf_get_int(ssh
->conf
, CONF_compression
)) {
5246 send_packet(ssh
, SSH1_CMSG_REQUEST_COMPRESSION
, PKT_INT
, 6, PKT_END
);
5250 if (pktin
->type
!= SSH1_SMSG_SUCCESS
5251 && pktin
->type
!= SSH1_SMSG_FAILURE
) {
5252 bombout(("Protocol confusion"));
5254 } else if (pktin
->type
== SSH1_SMSG_FAILURE
) {
5255 c_write_str(ssh
, "Server refused to compress\r\n");
5257 logevent("Started compression");
5258 ssh
->v1_compressing
= TRUE
;
5259 ssh
->cs_comp_ctx
= zlib_compress_init();
5260 logevent("Initialised zlib (RFC1950) compression");
5261 ssh
->sc_comp_ctx
= zlib_decompress_init();
5262 logevent("Initialised zlib (RFC1950) decompression");
5266 * Start the shell or command.
5268 * Special case: if the first-choice command is an SSH-2
5269 * subsystem (hence not usable here) and the second choice
5270 * exists, we fall straight back to that.
5273 char *cmd
= conf_get_str(ssh
->conf
, CONF_remote_cmd
);
5275 if (conf_get_int(ssh
->conf
, CONF_ssh_subsys
) &&
5276 conf_get_str(ssh
->conf
, CONF_remote_cmd2
)) {
5277 cmd
= conf_get_str(ssh
->conf
, CONF_remote_cmd2
);
5278 ssh
->fallback_cmd
= TRUE
;
5281 send_packet(ssh
, SSH1_CMSG_EXEC_CMD
, PKT_STR
, cmd
, PKT_END
);
5283 send_packet(ssh
, SSH1_CMSG_EXEC_SHELL
, PKT_END
);
5284 logevent("Started session");
5287 ssh
->state
= SSH_STATE_SESSION
;
5288 if (ssh
->size_needed
)
5289 ssh_size(ssh
, ssh
->term_width
, ssh
->term_height
);
5290 if (ssh
->eof_needed
)
5291 ssh_special(ssh
, TS_EOF
);
5294 ldisc_send(ssh
->ldisc
, NULL
, 0, 0);/* cause ldisc to notice changes */
5296 ssh
->channels
= newtree234(ssh_channelcmp
);
5300 * By this point, most incoming packets are already being
5301 * handled by the dispatch table, and we need only pay
5302 * attention to the unusual ones.
5307 if (pktin
->type
== SSH1_SMSG_SUCCESS
) {
5308 /* may be from EXEC_SHELL on some servers */
5309 } else if (pktin
->type
== SSH1_SMSG_FAILURE
) {
5310 /* may be from EXEC_SHELL on some servers
5311 * if no pty is available or in other odd cases. Ignore */
5313 bombout(("Strange packet received: type %d", pktin
->type
));
5318 int len
= min(inlen
, 512);
5319 send_packet(ssh
, SSH1_CMSG_STDIN_DATA
,
5320 PKT_INT
, len
, PKTT_DATA
, PKT_DATA
, in
, len
,
5321 PKTT_OTHER
, PKT_END
);
5332 * Handle the top-level SSH-2 protocol.
5334 static void ssh1_msg_debug(Ssh ssh
, struct Packet
*pktin
)
5339 ssh_pkt_getstring(pktin
, &msg
, &msglen
);
5340 logeventf(ssh
, "Remote debug message: %.*s", msglen
, msg
);
5343 static void ssh1_msg_disconnect(Ssh ssh
, struct Packet
*pktin
)
5345 /* log reason code in disconnect message */
5349 ssh_pkt_getstring(pktin
, &msg
, &msglen
);
5350 bombout(("Server sent disconnect message:\n\"%.*s\"", msglen
, msg
));
5353 static void ssh_msg_ignore(Ssh ssh
, struct Packet
*pktin
)
5355 /* Do nothing, because we're ignoring it! Duhh. */
5358 static void ssh1_protocol_setup(Ssh ssh
)
5363 * Most messages are handled by the coroutines.
5365 for (i
= 0; i
< 256; i
++)
5366 ssh
->packet_dispatch
[i
] = NULL
;
5369 * These special message types we install handlers for.
5371 ssh
->packet_dispatch
[SSH1_MSG_DISCONNECT
] = ssh1_msg_disconnect
;
5372 ssh
->packet_dispatch
[SSH1_MSG_IGNORE
] = ssh_msg_ignore
;
5373 ssh
->packet_dispatch
[SSH1_MSG_DEBUG
] = ssh1_msg_debug
;
5376 static void ssh1_protocol(Ssh ssh
, void *vin
, int inlen
,
5377 struct Packet
*pktin
)
5379 unsigned char *in
=(unsigned char*)vin
;
5380 if (ssh
->state
== SSH_STATE_CLOSED
)
5383 if (pktin
&& ssh
->packet_dispatch
[pktin
->type
]) {
5384 ssh
->packet_dispatch
[pktin
->type
](ssh
, pktin
);
5388 if (!ssh
->protocol_initial_phase_done
) {
5389 if (do_ssh1_login(ssh
, in
, inlen
, pktin
))
5390 ssh
->protocol_initial_phase_done
= TRUE
;
5395 do_ssh1_connection(ssh
, in
, inlen
, pktin
);
5399 * Utility routine for decoding comma-separated strings in KEXINIT.
5401 static int in_commasep_string(char *needle
, char *haystack
, int haylen
)
5404 if (!needle
|| !haystack
) /* protect against null pointers */
5406 needlen
= strlen(needle
);
5409 * Is it at the start of the string?
5411 if (haylen
>= needlen
&& /* haystack is long enough */
5412 !memcmp(needle
, haystack
, needlen
) && /* initial match */
5413 (haylen
== needlen
|| haystack
[needlen
] == ',')
5414 /* either , or EOS follows */
5418 * If not, search for the next comma and resume after that.
5419 * If no comma found, terminate.
5421 while (haylen
> 0 && *haystack
!= ',')
5422 haylen
--, haystack
++;
5425 haylen
--, haystack
++; /* skip over comma itself */
5430 * Similar routine for checking whether we have the first string in a list.
5432 static int first_in_commasep_string(char *needle
, char *haystack
, int haylen
)
5435 if (!needle
|| !haystack
) /* protect against null pointers */
5437 needlen
= strlen(needle
);
5439 * Is it at the start of the string?
5441 if (haylen
>= needlen
&& /* haystack is long enough */
5442 !memcmp(needle
, haystack
, needlen
) && /* initial match */
5443 (haylen
== needlen
|| haystack
[needlen
] == ',')
5444 /* either , or EOS follows */
5452 * SSH-2 key creation method.
5453 * (Currently assumes 2 lots of any hash are sufficient to generate
5454 * keys/IVs for any cipher/MAC. SSH2_MKKEY_ITERS documents this assumption.)
5456 #define SSH2_MKKEY_ITERS (2)
5457 static void ssh2_mkkey(Ssh ssh
, Bignum K
, unsigned char *H
, char chr
,
5458 unsigned char *keyspace
)
5460 const struct ssh_hash
*h
= ssh
->kex
->hash
;
5462 /* First hlen bytes. */
5464 if (!(ssh
->remote_bugs
& BUG_SSH2_DERIVEKEY
))
5465 hash_mpint(h
, s
, K
);
5466 h
->bytes(s
, H
, h
->hlen
);
5467 h
->bytes(s
, &chr
, 1);
5468 h
->bytes(s
, ssh
->v2_session_id
, ssh
->v2_session_id_len
);
5469 h
->final(s
, keyspace
);
5470 /* Next hlen bytes. */
5472 if (!(ssh
->remote_bugs
& BUG_SSH2_DERIVEKEY
))
5473 hash_mpint(h
, s
, K
);
5474 h
->bytes(s
, H
, h
->hlen
);
5475 h
->bytes(s
, keyspace
, h
->hlen
);
5476 h
->final(s
, keyspace
+ h
->hlen
);
5480 * Handle the SSH-2 transport layer.
5482 static int do_ssh2_transport(Ssh ssh
, void *vin
, int inlen
,
5483 struct Packet
*pktin
)
5485 unsigned char *in
= (unsigned char *)vin
;
5486 struct do_ssh2_transport_state
{
5488 int nbits
, pbits
, warn_kex
, warn_cscipher
, warn_sccipher
;
5489 Bignum p
, g
, e
, f
, K
;
5492 int kex_init_value
, kex_reply_value
;
5493 const struct ssh_mac
**maclist
;
5495 const struct ssh2_cipher
*cscipher_tobe
;
5496 const struct ssh2_cipher
*sccipher_tobe
;
5497 const struct ssh_mac
*csmac_tobe
;
5498 const struct ssh_mac
*scmac_tobe
;
5499 const struct ssh_compress
*cscomp_tobe
;
5500 const struct ssh_compress
*sccomp_tobe
;
5501 char *hostkeydata
, *sigdata
, *rsakeydata
, *keystr
, *fingerprint
;
5502 int hostkeylen
, siglen
, rsakeylen
;
5503 void *hkey
; /* actual host key */
5504 void *rsakey
; /* for RSA kex */
5505 unsigned char exchange_hash
[SSH2_KEX_MAX_HASH_LEN
];
5506 int n_preferred_kex
;
5507 const struct ssh_kexes
*preferred_kex
[KEX_MAX
];
5508 int n_preferred_ciphers
;
5509 const struct ssh2_ciphers
*preferred_ciphers
[CIPHER_MAX
];
5510 const struct ssh_compress
*preferred_comp
;
5511 int userauth_succeeded
; /* for delayed compression */
5512 int pending_compression
;
5513 int got_session_id
, activated_authconn
;
5514 struct Packet
*pktout
;
5519 crState(do_ssh2_transport_state
);
5523 s
->cscipher_tobe
= s
->sccipher_tobe
= NULL
;
5524 s
->csmac_tobe
= s
->scmac_tobe
= NULL
;
5525 s
->cscomp_tobe
= s
->sccomp_tobe
= NULL
;
5527 s
->got_session_id
= s
->activated_authconn
= FALSE
;
5528 s
->userauth_succeeded
= FALSE
;
5529 s
->pending_compression
= FALSE
;
5532 * Be prepared to work around the buggy MAC problem.
5534 if (ssh
->remote_bugs
& BUG_SSH2_HMAC
)
5535 s
->maclist
= buggymacs
, s
->nmacs
= lenof(buggymacs
);
5537 s
->maclist
= macs
, s
->nmacs
= lenof(macs
);
5540 ssh
->pkt_kctx
= SSH2_PKTCTX_NOKEX
;
5542 int i
, j
, k
, commalist_started
;
5545 * Set up the preferred key exchange. (NULL => warn below here)
5547 s
->n_preferred_kex
= 0;
5548 for (i
= 0; i
< KEX_MAX
; i
++) {
5549 switch (conf_get_int_int(ssh
->conf
, CONF_ssh_kexlist
, i
)) {
5551 s
->preferred_kex
[s
->n_preferred_kex
++] =
5552 &ssh_diffiehellman_gex
;
5555 s
->preferred_kex
[s
->n_preferred_kex
++] =
5556 &ssh_diffiehellman_group14
;
5559 s
->preferred_kex
[s
->n_preferred_kex
++] =
5560 &ssh_diffiehellman_group1
;
5563 s
->preferred_kex
[s
->n_preferred_kex
++] =
5567 /* Flag for later. Don't bother if it's the last in
5569 if (i
< KEX_MAX
- 1) {
5570 s
->preferred_kex
[s
->n_preferred_kex
++] = NULL
;
5577 * Set up the preferred ciphers. (NULL => warn below here)
5579 s
->n_preferred_ciphers
= 0;
5580 for (i
= 0; i
< CIPHER_MAX
; i
++) {
5581 switch (conf_get_int_int(ssh
->conf
, CONF_ssh_cipherlist
, i
)) {
5582 case CIPHER_BLOWFISH
:
5583 s
->preferred_ciphers
[s
->n_preferred_ciphers
++] = &ssh2_blowfish
;
5586 if (conf_get_int(ssh
->conf
, CONF_ssh2_des_cbc
)) {
5587 s
->preferred_ciphers
[s
->n_preferred_ciphers
++] = &ssh2_des
;
5591 s
->preferred_ciphers
[s
->n_preferred_ciphers
++] = &ssh2_3des
;
5594 s
->preferred_ciphers
[s
->n_preferred_ciphers
++] = &ssh2_aes
;
5596 case CIPHER_ARCFOUR
:
5597 s
->preferred_ciphers
[s
->n_preferred_ciphers
++] = &ssh2_arcfour
;
5600 /* Flag for later. Don't bother if it's the last in
5602 if (i
< CIPHER_MAX
- 1) {
5603 s
->preferred_ciphers
[s
->n_preferred_ciphers
++] = NULL
;
5610 * Set up preferred compression.
5612 if (conf_get_int(ssh
->conf
, CONF_compression
))
5613 s
->preferred_comp
= &ssh_zlib
;
5615 s
->preferred_comp
= &ssh_comp_none
;
5618 * Enable queueing of outgoing auth- or connection-layer
5619 * packets while we are in the middle of a key exchange.
5621 ssh
->queueing
= TRUE
;
5624 * Flag that KEX is in progress.
5626 ssh
->kex_in_progress
= TRUE
;
5629 * Construct and send our key exchange packet.
5631 s
->pktout
= ssh2_pkt_init(SSH2_MSG_KEXINIT
);
5632 for (i
= 0; i
< 16; i
++)
5633 ssh2_pkt_addbyte(s
->pktout
, (unsigned char) random_byte());
5634 /* List key exchange algorithms. */
5635 ssh2_pkt_addstring_start(s
->pktout
);
5636 commalist_started
= 0;
5637 for (i
= 0; i
< s
->n_preferred_kex
; i
++) {
5638 const struct ssh_kexes
*k
= s
->preferred_kex
[i
];
5639 if (!k
) continue; /* warning flag */
5640 for (j
= 0; j
< k
->nkexes
; j
++) {
5641 if (commalist_started
)
5642 ssh2_pkt_addstring_str(s
->pktout
, ",");
5643 ssh2_pkt_addstring_str(s
->pktout
, k
->list
[j
]->name
);
5644 commalist_started
= 1;
5647 /* List server host key algorithms. */
5648 ssh2_pkt_addstring_start(s
->pktout
);
5649 for (i
= 0; i
< lenof(hostkey_algs
); i
++) {
5650 ssh2_pkt_addstring_str(s
->pktout
, hostkey_algs
[i
]->name
);
5651 if (i
< lenof(hostkey_algs
) - 1)
5652 ssh2_pkt_addstring_str(s
->pktout
, ",");
5654 /* List encryption algorithms (client->server then server->client). */
5655 for (k
= 0; k
< 2; k
++) {
5656 ssh2_pkt_addstring_start(s
->pktout
);
5657 commalist_started
= 0;
5658 for (i
= 0; i
< s
->n_preferred_ciphers
; i
++) {
5659 const struct ssh2_ciphers
*c
= s
->preferred_ciphers
[i
];
5660 if (!c
) continue; /* warning flag */
5661 for (j
= 0; j
< c
->nciphers
; j
++) {
5662 if (commalist_started
)
5663 ssh2_pkt_addstring_str(s
->pktout
, ",");
5664 ssh2_pkt_addstring_str(s
->pktout
, c
->list
[j
]->name
);
5665 commalist_started
= 1;
5669 /* List MAC algorithms (client->server then server->client). */
5670 for (j
= 0; j
< 2; j
++) {
5671 ssh2_pkt_addstring_start(s
->pktout
);
5672 for (i
= 0; i
< s
->nmacs
; i
++) {
5673 ssh2_pkt_addstring_str(s
->pktout
, s
->maclist
[i
]->name
);
5674 if (i
< s
->nmacs
- 1)
5675 ssh2_pkt_addstring_str(s
->pktout
, ",");
5678 /* List client->server compression algorithms,
5679 * then server->client compression algorithms. (We use the
5680 * same set twice.) */
5681 for (j
= 0; j
< 2; j
++) {
5682 ssh2_pkt_addstring_start(s
->pktout
);
5683 assert(lenof(compressions
) > 1);
5684 /* Prefer non-delayed versions */
5685 ssh2_pkt_addstring_str(s
->pktout
, s
->preferred_comp
->name
);
5686 /* We don't even list delayed versions of algorithms until
5687 * they're allowed to be used, to avoid a race. See the end of
5689 if (s
->userauth_succeeded
&& s
->preferred_comp
->delayed_name
) {
5690 ssh2_pkt_addstring_str(s
->pktout
, ",");
5691 ssh2_pkt_addstring_str(s
->pktout
,
5692 s
->preferred_comp
->delayed_name
);
5694 for (i
= 0; i
< lenof(compressions
); i
++) {
5695 const struct ssh_compress
*c
= compressions
[i
];
5696 if (c
!= s
->preferred_comp
) {
5697 ssh2_pkt_addstring_str(s
->pktout
, ",");
5698 ssh2_pkt_addstring_str(s
->pktout
, c
->name
);
5699 if (s
->userauth_succeeded
&& c
->delayed_name
) {
5700 ssh2_pkt_addstring_str(s
->pktout
, ",");
5701 ssh2_pkt_addstring_str(s
->pktout
, c
->delayed_name
);
5706 /* List client->server languages. Empty list. */
5707 ssh2_pkt_addstring_start(s
->pktout
);
5708 /* List server->client languages. Empty list. */
5709 ssh2_pkt_addstring_start(s
->pktout
);
5710 /* First KEX packet does _not_ follow, because we're not that brave. */
5711 ssh2_pkt_addbool(s
->pktout
, FALSE
);
5713 ssh2_pkt_adduint32(s
->pktout
, 0);
5716 s
->our_kexinitlen
= s
->pktout
->length
- 5;
5717 s
->our_kexinit
= snewn(s
->our_kexinitlen
, unsigned char);
5718 memcpy(s
->our_kexinit
, s
->pktout
->data
+ 5, s
->our_kexinitlen
);
5720 ssh2_pkt_send_noqueue(ssh
, s
->pktout
);
5726 * Now examine the other side's KEXINIT to see what we're up
5730 char *str
, *preferred
;
5733 if (pktin
->type
!= SSH2_MSG_KEXINIT
) {
5734 bombout(("expected key exchange packet from server"));
5738 ssh
->hostkey
= NULL
;
5739 s
->cscipher_tobe
= NULL
;
5740 s
->sccipher_tobe
= NULL
;
5741 s
->csmac_tobe
= NULL
;
5742 s
->scmac_tobe
= NULL
;
5743 s
->cscomp_tobe
= NULL
;
5744 s
->sccomp_tobe
= NULL
;
5745 s
->warn_kex
= s
->warn_cscipher
= s
->warn_sccipher
= FALSE
;
5747 pktin
->savedpos
+= 16; /* skip garbage cookie */
5748 ssh_pkt_getstring(pktin
, &str
, &len
); /* key exchange algorithms */
5751 for (i
= 0; i
< s
->n_preferred_kex
; i
++) {
5752 const struct ssh_kexes
*k
= s
->preferred_kex
[i
];
5756 for (j
= 0; j
< k
->nkexes
; j
++) {
5757 if (!preferred
) preferred
= k
->list
[j
]->name
;
5758 if (in_commasep_string(k
->list
[j
]->name
, str
, len
)) {
5759 ssh
->kex
= k
->list
[j
];
5768 bombout(("Couldn't agree a key exchange algorithm (available: %s)",
5769 str ? str
: "(null)"));
5773 * Note that the server's guess is considered wrong if it doesn't match
5774 * the first algorithm in our list, even if it's still the algorithm
5777 s
->guessok
= first_in_commasep_string(preferred
, str
, len
);
5778 ssh_pkt_getstring(pktin
, &str
, &len
); /* host key algorithms */
5779 for (i
= 0; i
< lenof(hostkey_algs
); i
++) {
5780 if (in_commasep_string(hostkey_algs
[i
]->name
, str
, len
)) {
5781 ssh
->hostkey
= hostkey_algs
[i
];
5785 if (!ssh
->hostkey
) {
5786 bombout(("Couldn't agree a host key algorithm (available: %s)",
5787 str ? str
: "(null)"));
5791 s
->guessok
= s
->guessok
&&
5792 first_in_commasep_string(hostkey_algs
[0]->name
, str
, len
);
5793 ssh_pkt_getstring(pktin
, &str
, &len
); /* client->server cipher */
5794 for (i
= 0; i
< s
->n_preferred_ciphers
; i
++) {
5795 const struct ssh2_ciphers
*c
= s
->preferred_ciphers
[i
];
5797 s
->warn_cscipher
= TRUE
;
5799 for (j
= 0; j
< c
->nciphers
; j
++) {
5800 if (in_commasep_string(c
->list
[j
]->name
, str
, len
)) {
5801 s
->cscipher_tobe
= c
->list
[j
];
5806 if (s
->cscipher_tobe
)
5809 if (!s
->cscipher_tobe
) {
5810 bombout(("Couldn't agree a client-to-server cipher (available: %s)",
5811 str ? str
: "(null)"));
5815 ssh_pkt_getstring(pktin
, &str
, &len
); /* server->client cipher */
5816 for (i
= 0; i
< s
->n_preferred_ciphers
; i
++) {
5817 const struct ssh2_ciphers
*c
= s
->preferred_ciphers
[i
];
5819 s
->warn_sccipher
= TRUE
;
5821 for (j
= 0; j
< c
->nciphers
; j
++) {
5822 if (in_commasep_string(c
->list
[j
]->name
, str
, len
)) {
5823 s
->sccipher_tobe
= c
->list
[j
];
5828 if (s
->sccipher_tobe
)
5831 if (!s
->sccipher_tobe
) {
5832 bombout(("Couldn't agree a server-to-client cipher (available: %s)",
5833 str ? str
: "(null)"));
5837 ssh_pkt_getstring(pktin
, &str
, &len
); /* client->server mac */
5838 for (i
= 0; i
< s
->nmacs
; i
++) {
5839 if (in_commasep_string(s
->maclist
[i
]->name
, str
, len
)) {
5840 s
->csmac_tobe
= s
->maclist
[i
];
5844 ssh_pkt_getstring(pktin
, &str
, &len
); /* server->client mac */
5845 for (i
= 0; i
< s
->nmacs
; i
++) {
5846 if (in_commasep_string(s
->maclist
[i
]->name
, str
, len
)) {
5847 s
->scmac_tobe
= s
->maclist
[i
];
5851 ssh_pkt_getstring(pktin
, &str
, &len
); /* client->server compression */
5852 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
5853 const struct ssh_compress
*c
=
5854 i
== 0 ? s
->preferred_comp
: compressions
[i
- 1];
5855 if (in_commasep_string(c
->name
, str
, len
)) {
5858 } else if (in_commasep_string(c
->delayed_name
, str
, len
)) {
5859 if (s
->userauth_succeeded
) {
5863 s
->pending_compression
= TRUE
; /* try this later */
5867 ssh_pkt_getstring(pktin
, &str
, &len
); /* server->client compression */
5868 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
5869 const struct ssh_compress
*c
=
5870 i
== 0 ? s
->preferred_comp
: compressions
[i
- 1];
5871 if (in_commasep_string(c
->name
, str
, len
)) {
5874 } else if (in_commasep_string(c
->delayed_name
, str
, len
)) {
5875 if (s
->userauth_succeeded
) {
5879 s
->pending_compression
= TRUE
; /* try this later */
5883 if (s
->pending_compression
) {
5884 logevent("Server supports delayed compression; "
5885 "will try this later");
5887 ssh_pkt_getstring(pktin
, &str
, &len
); /* client->server language */
5888 ssh_pkt_getstring(pktin
, &str
, &len
); /* server->client language */
5889 s
->ignorepkt
= ssh2_pkt_getbool(pktin
) && !s
->guessok
;
5892 ssh_set_frozen(ssh
, 1);
5893 s
->dlgret
= askalg(ssh
->frontend
, "key-exchange algorithm",
5895 ssh_dialog_callback
, ssh
);
5896 if (s
->dlgret
< 0) {
5900 bombout(("Unexpected data from server while"
5901 " waiting for user response"));
5904 } while (pktin
|| inlen
> 0);
5905 s
->dlgret
= ssh
->user_response
;
5907 ssh_set_frozen(ssh
, 0);
5908 if (s
->dlgret
== 0) {
5909 ssh_disconnect(ssh
, "User aborted at kex warning", NULL
,
5915 if (s
->warn_cscipher
) {
5916 ssh_set_frozen(ssh
, 1);
5917 s
->dlgret
= askalg(ssh
->frontend
,
5918 "client-to-server cipher",
5919 s
->cscipher_tobe
->name
,
5920 ssh_dialog_callback
, ssh
);
5921 if (s
->dlgret
< 0) {
5925 bombout(("Unexpected data from server while"
5926 " waiting for user response"));
5929 } while (pktin
|| inlen
> 0);
5930 s
->dlgret
= ssh
->user_response
;
5932 ssh_set_frozen(ssh
, 0);
5933 if (s
->dlgret
== 0) {
5934 ssh_disconnect(ssh
, "User aborted at cipher warning", NULL
,
5940 if (s
->warn_sccipher
) {
5941 ssh_set_frozen(ssh
, 1);
5942 s
->dlgret
= askalg(ssh
->frontend
,
5943 "server-to-client cipher",
5944 s
->sccipher_tobe
->name
,
5945 ssh_dialog_callback
, ssh
);
5946 if (s
->dlgret
< 0) {
5950 bombout(("Unexpected data from server while"
5951 " waiting for user response"));
5954 } while (pktin
|| inlen
> 0);
5955 s
->dlgret
= ssh
->user_response
;
5957 ssh_set_frozen(ssh
, 0);
5958 if (s
->dlgret
== 0) {
5959 ssh_disconnect(ssh
, "User aborted at cipher warning", NULL
,
5965 ssh
->exhash
= ssh
->kex
->hash
->init();
5966 hash_string(ssh
->kex
->hash
, ssh
->exhash
, ssh
->v_c
, strlen(ssh
->v_c
));
5967 hash_string(ssh
->kex
->hash
, ssh
->exhash
, ssh
->v_s
, strlen(ssh
->v_s
));
5968 hash_string(ssh
->kex
->hash
, ssh
->exhash
,
5969 s
->our_kexinit
, s
->our_kexinitlen
);
5970 sfree(s
->our_kexinit
);
5971 if (pktin
->length
> 5)
5972 hash_string(ssh
->kex
->hash
, ssh
->exhash
,
5973 pktin
->data
+ 5, pktin
->length
- 5);
5975 if (s
->ignorepkt
) /* first_kex_packet_follows */
5976 crWaitUntil(pktin
); /* Ignore packet */
5979 if (ssh
->kex
->main_type
== KEXTYPE_DH
) {
5981 * Work out the number of bits of key we will need from the
5982 * key exchange. We start with the maximum key length of
5988 csbits
= s
->cscipher_tobe
->keylen
;
5989 scbits
= s
->sccipher_tobe
->keylen
;
5990 s
->nbits
= (csbits
> scbits ? csbits
: scbits
);
5992 /* The keys only have hlen-bit entropy, since they're based on
5993 * a hash. So cap the key size at hlen bits. */
5994 if (s
->nbits
> ssh
->kex
->hash
->hlen
* 8)
5995 s
->nbits
= ssh
->kex
->hash
->hlen
* 8;
5998 * If we're doing Diffie-Hellman group exchange, start by
5999 * requesting a group.
6001 if (!ssh
->kex
->pdata
) {
6002 logevent("Doing Diffie-Hellman group exchange");
6003 ssh
->pkt_kctx
= SSH2_PKTCTX_DHGEX
;
6005 * Work out how big a DH group we will need to allow that
6008 s
->pbits
= 512 << ((s
->nbits
- 1) / 64);
6009 s
->pktout
= ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST
);
6010 ssh2_pkt_adduint32(s
->pktout
, s
->pbits
);
6011 ssh2_pkt_send_noqueue(ssh
, s
->pktout
);
6014 if (pktin
->type
!= SSH2_MSG_KEX_DH_GEX_GROUP
) {
6015 bombout(("expected key exchange group packet from server"));
6018 s
->p
= ssh2_pkt_getmp(pktin
);
6019 s
->g
= ssh2_pkt_getmp(pktin
);
6020 if (!s
->p
|| !s
->g
) {
6021 bombout(("unable to read mp-ints from incoming group packet"));
6024 ssh
->kex_ctx
= dh_setup_gex(s
->p
, s
->g
);
6025 s
->kex_init_value
= SSH2_MSG_KEX_DH_GEX_INIT
;
6026 s
->kex_reply_value
= SSH2_MSG_KEX_DH_GEX_REPLY
;
6028 ssh
->pkt_kctx
= SSH2_PKTCTX_DHGROUP
;
6029 ssh
->kex_ctx
= dh_setup_group(ssh
->kex
);
6030 s
->kex_init_value
= SSH2_MSG_KEXDH_INIT
;
6031 s
->kex_reply_value
= SSH2_MSG_KEXDH_REPLY
;
6032 logeventf(ssh
, "Using Diffie-Hellman with standard group \"%s\"",
6033 ssh
->kex
->groupname
);
6036 logeventf(ssh
, "Doing Diffie-Hellman key exchange with hash %s",
6037 ssh
->kex
->hash
->text_name
);
6039 * Now generate and send e for Diffie-Hellman.
6041 set_busy_status(ssh
->frontend
, BUSY_CPU
); /* this can take a while */
6042 s
->e
= dh_create_e(ssh
->kex_ctx
, s
->nbits
* 2);
6043 s
->pktout
= ssh2_pkt_init(s
->kex_init_value
);
6044 ssh2_pkt_addmp(s
->pktout
, s
->e
);
6045 ssh2_pkt_send_noqueue(ssh
, s
->pktout
);
6047 set_busy_status(ssh
->frontend
, BUSY_WAITING
); /* wait for server */
6049 if (pktin
->type
!= s
->kex_reply_value
) {
6050 bombout(("expected key exchange reply packet from server"));
6053 set_busy_status(ssh
->frontend
, BUSY_CPU
); /* cogitate */
6054 ssh_pkt_getstring(pktin
, &s
->hostkeydata
, &s
->hostkeylen
);
6055 s
->hkey
= ssh
->hostkey
->newkey(s
->hostkeydata
, s
->hostkeylen
);
6056 s
->f
= ssh2_pkt_getmp(pktin
);
6058 bombout(("unable to parse key exchange reply packet"));
6061 ssh_pkt_getstring(pktin
, &s
->sigdata
, &s
->siglen
);
6063 s
->K
= dh_find_K(ssh
->kex_ctx
, s
->f
);
6065 /* We assume everything from now on will be quick, and it might
6066 * involve user interaction. */
6067 set_busy_status(ssh
->frontend
, BUSY_NOT
);
6069 hash_string(ssh
->kex
->hash
, ssh
->exhash
, s
->hostkeydata
, s
->hostkeylen
);
6070 if (!ssh
->kex
->pdata
) {
6071 hash_uint32(ssh
->kex
->hash
, ssh
->exhash
, s
->pbits
);
6072 hash_mpint(ssh
->kex
->hash
, ssh
->exhash
, s
->p
);
6073 hash_mpint(ssh
->kex
->hash
, ssh
->exhash
, s
->g
);
6075 hash_mpint(ssh
->kex
->hash
, ssh
->exhash
, s
->e
);
6076 hash_mpint(ssh
->kex
->hash
, ssh
->exhash
, s
->f
);
6078 dh_cleanup(ssh
->kex_ctx
);
6080 if (!ssh
->kex
->pdata
) {
6085 logeventf(ssh
, "Doing RSA key exchange with hash %s",
6086 ssh
->kex
->hash
->text_name
);
6087 ssh
->pkt_kctx
= SSH2_PKTCTX_RSAKEX
;
6089 * RSA key exchange. First expect a KEXRSA_PUBKEY packet
6093 if (pktin
->type
!= SSH2_MSG_KEXRSA_PUBKEY
) {
6094 bombout(("expected RSA public key packet from server"));
6098 ssh_pkt_getstring(pktin
, &s
->hostkeydata
, &s
->hostkeylen
);
6099 hash_string(ssh
->kex
->hash
, ssh
->exhash
,
6100 s
->hostkeydata
, s
->hostkeylen
);
6101 s
->hkey
= ssh
->hostkey
->newkey(s
->hostkeydata
, s
->hostkeylen
);
6105 ssh_pkt_getstring(pktin
, &keydata
, &s
->rsakeylen
);
6106 s
->rsakeydata
= snewn(s
->rsakeylen
, char);
6107 memcpy(s
->rsakeydata
, keydata
, s
->rsakeylen
);
6110 s
->rsakey
= ssh_rsakex_newkey(s
->rsakeydata
, s
->rsakeylen
);
6112 sfree(s
->rsakeydata
);
6113 bombout(("unable to parse RSA public key from server"));
6117 hash_string(ssh
->kex
->hash
, ssh
->exhash
, s
->rsakeydata
, s
->rsakeylen
);
6120 * Next, set up a shared secret K, of precisely KLEN -
6121 * 2*HLEN - 49 bits, where KLEN is the bit length of the
6122 * RSA key modulus and HLEN is the bit length of the hash
6126 int klen
= ssh_rsakex_klen(s
->rsakey
);
6127 int nbits
= klen
- (2*ssh
->kex
->hash
->hlen
*8 + 49);
6129 unsigned char *kstr1
, *kstr2
, *outstr
;
6130 int kstr1len
, kstr2len
, outstrlen
;
6132 s
->K
= bn_power_2(nbits
- 1);
6134 for (i
= 0; i
< nbits
; i
++) {
6136 byte
= random_byte();
6138 bignum_set_bit(s
->K
, i
, (byte
>> (i
& 7)) & 1);
6142 * Encode this as an mpint.
6144 kstr1
= ssh2_mpint_fmt(s
->K
, &kstr1len
);
6145 kstr2
= snewn(kstr2len
= 4 + kstr1len
, unsigned char);
6146 PUT_32BIT(kstr2
, kstr1len
);
6147 memcpy(kstr2
+ 4, kstr1
, kstr1len
);
6150 * Encrypt it with the given RSA key.
6152 outstrlen
= (klen
+ 7) / 8;
6153 outstr
= snewn(outstrlen
, unsigned char);
6154 ssh_rsakex_encrypt(ssh
->kex
->hash
, kstr2
, kstr2len
,
6155 outstr
, outstrlen
, s
->rsakey
);
6158 * And send it off in a return packet.
6160 s
->pktout
= ssh2_pkt_init(SSH2_MSG_KEXRSA_SECRET
);
6161 ssh2_pkt_addstring_start(s
->pktout
);
6162 ssh2_pkt_addstring_data(s
->pktout
, (char *)outstr
, outstrlen
);
6163 ssh2_pkt_send_noqueue(ssh
, s
->pktout
);
6165 hash_string(ssh
->kex
->hash
, ssh
->exhash
, outstr
, outstrlen
);
6172 ssh_rsakex_freekey(s
->rsakey
);
6175 if (pktin
->type
!= SSH2_MSG_KEXRSA_DONE
) {
6176 sfree(s
->rsakeydata
);
6177 bombout(("expected signature packet from server"));
6181 ssh_pkt_getstring(pktin
, &s
->sigdata
, &s
->siglen
);
6183 sfree(s
->rsakeydata
);
6186 hash_mpint(ssh
->kex
->hash
, ssh
->exhash
, s
->K
);
6187 assert(ssh
->kex
->hash
->hlen
<= sizeof(s
->exchange_hash
));
6188 ssh
->kex
->hash
->final(ssh
->exhash
, s
->exchange_hash
);
6190 ssh
->kex_ctx
= NULL
;
6193 debug(("Exchange hash is:\n"));
6194 dmemdump(s
->exchange_hash
, ssh
->kex
->hash
->hlen
);
6198 !ssh
->hostkey
->verifysig(s
->hkey
, s
->sigdata
, s
->siglen
,
6199 (char *)s
->exchange_hash
,
6200 ssh
->kex
->hash
->hlen
)) {
6201 bombout(("Server's host key did not match the signature supplied"));
6206 * Authenticate remote host: verify host key. (We've already
6207 * checked the signature of the exchange hash.)
6209 s
->keystr
= ssh
->hostkey
->fmtkey(s
->hkey
);
6210 s
->fingerprint
= ssh
->hostkey
->fingerprint(s
->hkey
);
6211 ssh_set_frozen(ssh
, 1);
6212 s
->dlgret
= verify_ssh_host_key(ssh
->frontend
,
6213 ssh
->savedhost
, ssh
->savedport
,
6214 ssh
->hostkey
->keytype
, s
->keystr
,
6216 ssh_dialog_callback
, ssh
);
6217 if (s
->dlgret
< 0) {
6221 bombout(("Unexpected data from server while waiting"
6222 " for user host key response"));
6225 } while (pktin
|| inlen
> 0);
6226 s
->dlgret
= ssh
->user_response
;
6228 ssh_set_frozen(ssh
, 0);
6229 if (s
->dlgret
== 0) {
6230 ssh_disconnect(ssh
, "User aborted at host key verification", NULL
,
6234 if (!s
->got_session_id
) { /* don't bother logging this in rekeys */
6235 logevent("Host key fingerprint is:");
6236 logevent(s
->fingerprint
);
6238 sfree(s
->fingerprint
);
6240 ssh
->hostkey
->freekey(s
->hkey
);
6243 * The exchange hash from the very first key exchange is also
6244 * the session id, used in session key construction and
6247 if (!s
->got_session_id
) {
6248 assert(sizeof(s
->exchange_hash
) <= sizeof(ssh
->v2_session_id
));
6249 memcpy(ssh
->v2_session_id
, s
->exchange_hash
,
6250 sizeof(s
->exchange_hash
));
6251 ssh
->v2_session_id_len
= ssh
->kex
->hash
->hlen
;
6252 assert(ssh
->v2_session_id_len
<= sizeof(ssh
->v2_session_id
));
6253 s
->got_session_id
= TRUE
;
6257 * Send SSH2_MSG_NEWKEYS.
6259 s
->pktout
= ssh2_pkt_init(SSH2_MSG_NEWKEYS
);
6260 ssh2_pkt_send_noqueue(ssh
, s
->pktout
);
6261 ssh
->outgoing_data_size
= 0; /* start counting from here */
6264 * We've sent client NEWKEYS, so create and initialise
6265 * client-to-server session keys.
6267 if (ssh
->cs_cipher_ctx
)
6268 ssh
->cscipher
->free_context(ssh
->cs_cipher_ctx
);
6269 ssh
->cscipher
= s
->cscipher_tobe
;
6270 ssh
->cs_cipher_ctx
= ssh
->cscipher
->make_context();
6272 if (ssh
->cs_mac_ctx
)
6273 ssh
->csmac
->free_context(ssh
->cs_mac_ctx
);
6274 ssh
->csmac
= s
->csmac_tobe
;
6275 ssh
->cs_mac_ctx
= ssh
->csmac
->make_context();
6277 if (ssh
->cs_comp_ctx
)
6278 ssh
->cscomp
->compress_cleanup(ssh
->cs_comp_ctx
);
6279 ssh
->cscomp
= s
->cscomp_tobe
;
6280 ssh
->cs_comp_ctx
= ssh
->cscomp
->compress_init();
6283 * Set IVs on client-to-server keys. Here we use the exchange
6284 * hash from the _first_ key exchange.
6287 unsigned char keyspace
[SSH2_KEX_MAX_HASH_LEN
* SSH2_MKKEY_ITERS
];
6288 assert(sizeof(keyspace
) >= ssh
->kex
->hash
->hlen
* SSH2_MKKEY_ITERS
);
6289 ssh2_mkkey(ssh
,s
->K
,s
->exchange_hash
,'C',keyspace
);
6290 assert((ssh
->cscipher
->keylen
+7) / 8 <=
6291 ssh
->kex
->hash
->hlen
* SSH2_MKKEY_ITERS
);
6292 ssh
->cscipher
->setkey(ssh
->cs_cipher_ctx
, keyspace
);
6293 ssh2_mkkey(ssh
,s
->K
,s
->exchange_hash
,'A',keyspace
);
6294 assert(ssh
->cscipher
->blksize
<=
6295 ssh
->kex
->hash
->hlen
* SSH2_MKKEY_ITERS
);
6296 ssh
->cscipher
->setiv(ssh
->cs_cipher_ctx
, keyspace
);
6297 ssh2_mkkey(ssh
,s
->K
,s
->exchange_hash
,'E',keyspace
);
6298 assert(ssh
->csmac
->len
<=
6299 ssh
->kex
->hash
->hlen
* SSH2_MKKEY_ITERS
);
6300 ssh
->csmac
->setkey(ssh
->cs_mac_ctx
, keyspace
);
6301 smemclr(keyspace
, sizeof(keyspace
));
6304 logeventf(ssh
, "Initialised %.200s client->server encryption",
6305 ssh
->cscipher
->text_name
);
6306 logeventf(ssh
, "Initialised %.200s client->server MAC algorithm",
6307 ssh
->csmac
->text_name
);
6308 if (ssh
->cscomp
->text_name
)
6309 logeventf(ssh
, "Initialised %s compression",
6310 ssh
->cscomp
->text_name
);
6313 * Now our end of the key exchange is complete, we can send all
6314 * our queued higher-layer packets.
6316 ssh
->queueing
= FALSE
;
6317 ssh2_pkt_queuesend(ssh
);
6320 * Expect SSH2_MSG_NEWKEYS from server.
6323 if (pktin
->type
!= SSH2_MSG_NEWKEYS
) {
6324 bombout(("expected new-keys packet from server"));
6327 ssh
->incoming_data_size
= 0; /* start counting from here */
6330 * We've seen server NEWKEYS, so create and initialise
6331 * server-to-client session keys.
6333 if (ssh
->sc_cipher_ctx
)
6334 ssh
->sccipher
->free_context(ssh
->sc_cipher_ctx
);
6335 ssh
->sccipher
= s
->sccipher_tobe
;
6336 ssh
->sc_cipher_ctx
= ssh
->sccipher
->make_context();
6338 if (ssh
->sc_mac_ctx
)
6339 ssh
->scmac
->free_context(ssh
->sc_mac_ctx
);
6340 ssh
->scmac
= s
->scmac_tobe
;
6341 ssh
->sc_mac_ctx
= ssh
->scmac
->make_context();
6343 if (ssh
->sc_comp_ctx
)
6344 ssh
->sccomp
->decompress_cleanup(ssh
->sc_comp_ctx
);
6345 ssh
->sccomp
= s
->sccomp_tobe
;
6346 ssh
->sc_comp_ctx
= ssh
->sccomp
->decompress_init();
6349 * Set IVs on server-to-client keys. Here we use the exchange
6350 * hash from the _first_ key exchange.
6353 unsigned char keyspace
[SSH2_KEX_MAX_HASH_LEN
* SSH2_MKKEY_ITERS
];
6354 assert(sizeof(keyspace
) >= ssh
->kex
->hash
->hlen
* SSH2_MKKEY_ITERS
);
6355 ssh2_mkkey(ssh
,s
->K
,s
->exchange_hash
,'D',keyspace
);
6356 assert((ssh
->sccipher
->keylen
+7) / 8 <=
6357 ssh
->kex
->hash
->hlen
* SSH2_MKKEY_ITERS
);
6358 ssh
->sccipher
->setkey(ssh
->sc_cipher_ctx
, keyspace
);
6359 ssh2_mkkey(ssh
,s
->K
,s
->exchange_hash
,'B',keyspace
);
6360 assert(ssh
->sccipher
->blksize
<=
6361 ssh
->kex
->hash
->hlen
* SSH2_MKKEY_ITERS
);
6362 ssh
->sccipher
->setiv(ssh
->sc_cipher_ctx
, keyspace
);
6363 ssh2_mkkey(ssh
,s
->K
,s
->exchange_hash
,'F',keyspace
);
6364 assert(ssh
->scmac
->len
<=
6365 ssh
->kex
->hash
->hlen
* SSH2_MKKEY_ITERS
);
6366 ssh
->scmac
->setkey(ssh
->sc_mac_ctx
, keyspace
);
6367 smemclr(keyspace
, sizeof(keyspace
));
6369 logeventf(ssh
, "Initialised %.200s server->client encryption",
6370 ssh
->sccipher
->text_name
);
6371 logeventf(ssh
, "Initialised %.200s server->client MAC algorithm",
6372 ssh
->scmac
->text_name
);
6373 if (ssh
->sccomp
->text_name
)
6374 logeventf(ssh
, "Initialised %s decompression",
6375 ssh
->sccomp
->text_name
);
6378 * Free shared secret.
6383 * Key exchange is over. Loop straight back round if we have a
6384 * deferred rekey reason.
6386 if (ssh
->deferred_rekey_reason
) {
6387 logevent(ssh
->deferred_rekey_reason
);
6389 ssh
->deferred_rekey_reason
= NULL
;
6390 goto begin_key_exchange
;
6394 * Otherwise, schedule a timer for our next rekey.
6396 ssh
->kex_in_progress
= FALSE
;
6397 ssh
->last_rekey
= GETTICKCOUNT();
6398 if (conf_get_int(ssh
->conf
, CONF_ssh_rekey_time
) != 0)
6399 ssh
->next_rekey
= schedule_timer(conf_get_int(ssh
->conf
, CONF_ssh_rekey_time
)*60*TICKSPERSEC
,
6403 * Now we're encrypting. Begin returning 1 to the protocol main
6404 * function so that other things can run on top of the
6405 * transport. If we ever see a KEXINIT, we must go back to the
6408 * We _also_ go back to the start if we see pktin==NULL and
6409 * inlen negative, because this is a special signal meaning
6410 * `initiate client-driven rekey', and `in' contains a message
6411 * giving the reason for the rekey.
6413 * inlen==-1 means always initiate a rekey;
6414 * inlen==-2 means that userauth has completed successfully and
6415 * we should consider rekeying (for delayed compression).
6417 while (!((pktin
&& pktin
->type
== SSH2_MSG_KEXINIT
) ||
6418 (!pktin
&& inlen
< 0))) {
6420 if (!ssh
->protocol_initial_phase_done
) {
6421 ssh
->protocol_initial_phase_done
= TRUE
;
6423 * Allow authconn to initialise itself.
6425 do_ssh2_authconn(ssh
, NULL
, 0, NULL
);
6430 logevent("Server initiated key re-exchange");
6434 * authconn has seen a USERAUTH_SUCCEEDED. Time to enable
6435 * delayed compression, if it's available.
6437 * draft-miller-secsh-compression-delayed-00 says that you
6438 * negotiate delayed compression in the first key exchange, and
6439 * both sides start compressing when the server has sent
6440 * USERAUTH_SUCCESS. This has a race condition -- the server
6441 * can't know when the client has seen it, and thus which incoming
6442 * packets it should treat as compressed.
6444 * Instead, we do the initial key exchange without offering the
6445 * delayed methods, but note if the server offers them; when we
6446 * get here, if a delayed method was available that was higher
6447 * on our list than what we got, we initiate a rekey in which we
6448 * _do_ list the delayed methods (and hopefully get it as a
6449 * result). Subsequent rekeys will do the same.
6451 assert(!s
->userauth_succeeded
); /* should only happen once */
6452 s
->userauth_succeeded
= TRUE
;
6453 if (!s
->pending_compression
)
6454 /* Can't see any point rekeying. */
6455 goto wait_for_rekey
; /* this is utterly horrid */
6456 /* else fall through to rekey... */
6457 s
->pending_compression
= FALSE
;
6460 * Now we've decided to rekey.
6462 * Special case: if the server bug is set that doesn't
6463 * allow rekeying, we give a different log message and
6464 * continue waiting. (If such a server _initiates_ a rekey,
6465 * we process it anyway!)
6467 if ((ssh
->remote_bugs
& BUG_SSH2_REKEY
)) {
6468 logeventf(ssh
, "Server bug prevents key re-exchange (%s)",
6470 /* Reset the counters, so that at least this message doesn't
6471 * hit the event log _too_ often. */
6472 ssh
->outgoing_data_size
= 0;
6473 ssh
->incoming_data_size
= 0;
6474 if (conf_get_int(ssh
->conf
, CONF_ssh_rekey_time
) != 0) {
6476 schedule_timer(conf_get_int(ssh
->conf
, CONF_ssh_rekey_time
)*60*TICKSPERSEC
,
6479 goto wait_for_rekey
; /* this is still utterly horrid */
6481 logeventf(ssh
, "Initiating key re-exchange (%s)", (char *)in
);
6484 goto begin_key_exchange
;
6490 * Add data to an SSH-2 channel output buffer.
6492 static void ssh2_add_channel_data(struct ssh_channel
*c
, char *buf
,
6495 bufchain_add(&c
->v
.v2
.outbuffer
, buf
, len
);
6499 * Attempt to send data on an SSH-2 channel.
6501 static int ssh2_try_send(struct ssh_channel
*c
)
6504 struct Packet
*pktout
;
6507 while (c
->v
.v2
.remwindow
> 0 && bufchain_size(&c
->v
.v2
.outbuffer
) > 0) {
6510 bufchain_prefix(&c
->v
.v2
.outbuffer
, &data
, &len
);
6511 if ((unsigned)len
> c
->v
.v2
.remwindow
)
6512 len
= c
->v
.v2
.remwindow
;
6513 if ((unsigned)len
> c
->v
.v2
.remmaxpkt
)
6514 len
= c
->v
.v2
.remmaxpkt
;
6515 pktout
= ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA
);
6516 ssh2_pkt_adduint32(pktout
, c
->remoteid
);
6517 ssh2_pkt_addstring_start(pktout
);
6518 dont_log_data(ssh
, pktout
, PKTLOG_OMIT
);
6519 ssh2_pkt_addstring_data(pktout
, data
, len
);
6520 end_log_omission(ssh
, pktout
);
6521 ssh2_pkt_send(ssh
, pktout
);
6522 bufchain_consume(&c
->v
.v2
.outbuffer
, len
);
6523 c
->v
.v2
.remwindow
-= len
;
6527 * After having sent as much data as we can, return the amount
6530 ret
= bufchain_size(&c
->v
.v2
.outbuffer
);
6533 * And if there's no data pending but we need to send an EOF, send
6536 if (!ret
&& c
->pending_eof
)
6537 ssh_channel_try_eof(c
);
6542 static void ssh2_try_send_and_unthrottle(Ssh ssh
, struct ssh_channel
*c
)
6545 if (c
->closes
& CLOSES_SENT_EOF
)
6546 return; /* don't send on channels we've EOFed */
6547 bufsize
= ssh2_try_send(c
);
6550 case CHAN_MAINSESSION
:
6551 /* stdin need not receive an unthrottle
6552 * notification since it will be polled */
6555 x11_unthrottle(c
->u
.x11
.s
);
6558 /* agent sockets are request/response and need no
6559 * buffer management */
6562 pfd_unthrottle(c
->u
.pfd
.s
);
6569 * Set up most of a new ssh_channel for SSH-2.
6571 static void ssh2_channel_init(struct ssh_channel
*c
)
6574 c
->localid
= alloc_channel_id(ssh
);
6576 c
->pending_eof
= FALSE
;
6577 c
->throttling_conn
= FALSE
;
6578 c
->v
.v2
.locwindow
= c
->v
.v2
.locmaxwin
= c
->v
.v2
.remlocwin
=
6579 conf_get_int(ssh
->conf
, CONF_ssh_simple
) ? OUR_V2_BIGWIN
: OUR_V2_WINSIZE
;
6580 c
->v
.v2
.chanreq_head
= NULL
;
6581 c
->v
.v2
.throttle_state
= UNTHROTTLED
;
6582 bufchain_init(&c
->v
.v2
.outbuffer
);
6586 * CHANNEL_FAILURE doesn't come with any indication of what message
6587 * caused it, so we have to keep track of the outstanding
6588 * CHANNEL_REQUESTs ourselves.
6590 static void ssh2_queue_chanreq_handler(struct ssh_channel
*c
,
6591 cchandler_fn_t handler
, void *ctx
)
6593 struct outstanding_channel_request
*ocr
=
6594 snew(struct outstanding_channel_request
);
6596 assert(!(c
->closes
& (CLOSES_SENT_CLOSE
| CLOSES_RCVD_CLOSE
)));
6597 ocr
->handler
= handler
;
6600 if (!c
->v
.v2
.chanreq_head
)
6601 c
->v
.v2
.chanreq_head
= ocr
;
6603 c
->v
.v2
.chanreq_tail
->next
= ocr
;
6604 c
->v
.v2
.chanreq_tail
= ocr
;
6608 * Construct the common parts of a CHANNEL_REQUEST. If handler is not
6609 * NULL then a reply will be requested and the handler will be called
6610 * when it arrives. The returned packet is ready to have any
6611 * request-specific data added and be sent. Note that if a handler is
6612 * provided, it's essential that the request actually be sent.
6614 * The handler will usually be passed the response packet in pktin.
6615 * If pktin is NULL, this means that no reply will ever be forthcoming
6616 * (e.g. because the entire connection is being destroyed) and the
6617 * handler should free any storage it's holding.
6619 static struct Packet
*ssh2_chanreq_init(struct ssh_channel
*c
, char *type
,
6620 cchandler_fn_t handler
, void *ctx
)
6622 struct Packet
*pktout
;
6624 assert(!(c
->closes
& (CLOSES_SENT_CLOSE
| CLOSES_RCVD_CLOSE
)));
6625 pktout
= ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
6626 ssh2_pkt_adduint32(pktout
, c
->remoteid
);
6627 ssh2_pkt_addstring(pktout
, type
);
6628 ssh2_pkt_addbool(pktout
, handler
!= NULL
);
6629 if (handler
!= NULL
)
6630 ssh2_queue_chanreq_handler(c
, handler
, ctx
);
6635 * Potentially enlarge the window on an SSH-2 channel.
6637 static void ssh2_handle_winadj_response(struct ssh_channel
*, struct Packet
*,
6639 static void ssh2_set_window(struct ssh_channel
*c
, int newwin
)
6644 * Never send WINDOW_ADJUST for a channel that the remote side has
6645 * already sent EOF on; there's no point, since it won't be
6646 * sending any more data anyway. Ditto if _we've_ already sent
6649 if (c
->closes
& (CLOSES_RCVD_EOF
| CLOSES_SENT_CLOSE
))
6653 * If the remote end has a habit of ignoring maxpkt, limit the
6654 * window so that it has no choice (assuming it doesn't ignore the
6657 if ((ssh
->remote_bugs
& BUG_SSH2_MAXPKT
) && newwin
> OUR_V2_MAXPKT
)
6658 newwin
= OUR_V2_MAXPKT
;
6661 * Only send a WINDOW_ADJUST if there's significantly more window
6662 * available than the other end thinks there is. This saves us
6663 * sending a WINDOW_ADJUST for every character in a shell session.
6665 * "Significant" is arbitrarily defined as half the window size.
6667 if (newwin
/ 2 >= c
->v
.v2
.locwindow
) {
6668 struct Packet
*pktout
;
6672 * In order to keep track of how much window the client
6673 * actually has available, we'd like it to acknowledge each
6674 * WINDOW_ADJUST. We can't do that directly, so we accompany
6675 * it with a CHANNEL_REQUEST that has to be acknowledged.
6677 * This is only necessary if we're opening the window wide.
6678 * If we're not, then throughput is being constrained by
6679 * something other than the maximum window size anyway.
6681 if (newwin
== c
->v
.v2
.locmaxwin
&&
6682 !(ssh
->remote_bugs
& BUG_CHOKES_ON_WINADJ
)) {
6683 up
= snew(unsigned);
6684 *up
= newwin
- c
->v
.v2
.locwindow
;
6685 pktout
= ssh2_chanreq_init(c
, "winadj@putty.projects.tartarus.org",
6686 ssh2_handle_winadj_response
, up
);
6687 ssh2_pkt_send(ssh
, pktout
);
6689 if (c
->v
.v2
.throttle_state
!= UNTHROTTLED
)
6690 c
->v
.v2
.throttle_state
= UNTHROTTLING
;
6692 /* Pretend the WINDOW_ADJUST was acked immediately. */
6693 c
->v
.v2
.remlocwin
= newwin
;
6694 c
->v
.v2
.throttle_state
= THROTTLED
;
6696 pktout
= ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
6697 ssh2_pkt_adduint32(pktout
, c
->remoteid
);
6698 ssh2_pkt_adduint32(pktout
, newwin
- c
->v
.v2
.locwindow
);
6699 ssh2_pkt_send(ssh
, pktout
);
6700 c
->v
.v2
.locwindow
= newwin
;
6705 * Find the channel associated with a message. If there's no channel,
6706 * or it's not properly open, make a noise about it and return NULL.
6708 static struct ssh_channel
*ssh2_channel_msg(Ssh ssh
, struct Packet
*pktin
)
6710 unsigned localid
= ssh_pkt_getuint32(pktin
);
6711 struct ssh_channel
*c
;
6713 c
= find234(ssh
->channels
, &localid
, ssh_channelfind
);
6715 (c
->halfopen
&& pktin
->type
!= SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
&&
6716 pktin
->type
!= SSH2_MSG_CHANNEL_OPEN_FAILURE
)) {
6717 char *buf
= dupprintf("Received %s for %s channel %u",
6718 ssh2_pkt_type(ssh
->pkt_kctx
, ssh
->pkt_actx
,
6720 c ?
"half-open" : "nonexistent", localid
);
6721 ssh_disconnect(ssh
, NULL
, buf
, SSH2_DISCONNECT_PROTOCOL_ERROR
, FALSE
);
6728 static void ssh2_handle_winadj_response(struct ssh_channel
*c
,
6729 struct Packet
*pktin
, void *ctx
)
6731 unsigned *sizep
= ctx
;
6734 * Winadj responses should always be failures. However, at least
6735 * one server ("boks_sshd") is known to return SUCCESS for channel
6736 * requests it's never heard of, such as "winadj@putty". Raised
6737 * with foxt.com as bug 090916-090424, but for the sake of a quiet
6738 * life, we don't worry about what kind of response we got.
6741 c
->v
.v2
.remlocwin
+= *sizep
;
6744 * winadj messages are only sent when the window is fully open, so
6745 * if we get an ack of one, we know any pending unthrottle is
6748 if (c
->v
.v2
.throttle_state
== UNTHROTTLING
)
6749 c
->v
.v2
.throttle_state
= UNTHROTTLED
;
6752 static void ssh2_msg_channel_response(Ssh ssh
, struct Packet
*pktin
)
6754 struct ssh_channel
*c
= ssh2_channel_msg(ssh
, pktin
);
6755 struct outstanding_channel_request
*ocr
;
6758 ocr
= c
->v
.v2
.chanreq_head
;
6760 ssh2_msg_unexpected(ssh
, pktin
);
6763 ocr
->handler(c
, pktin
, ocr
->ctx
);
6764 c
->v
.v2
.chanreq_head
= ocr
->next
;
6767 * We may now initiate channel-closing procedures, if that
6768 * CHANNEL_REQUEST was the last thing outstanding before we send
6771 ssh2_channel_check_close(c
);
6774 static void ssh2_msg_channel_window_adjust(Ssh ssh
, struct Packet
*pktin
)
6776 struct ssh_channel
*c
;
6777 c
= ssh2_channel_msg(ssh
, pktin
);
6780 if (!(c
->closes
& CLOSES_SENT_EOF
)) {
6781 c
->v
.v2
.remwindow
+= ssh_pkt_getuint32(pktin
);
6782 ssh2_try_send_and_unthrottle(ssh
, c
);
6786 static void ssh2_msg_channel_data(Ssh ssh
, struct Packet
*pktin
)
6790 struct ssh_channel
*c
;
6791 c
= ssh2_channel_msg(ssh
, pktin
);
6794 if (pktin
->type
== SSH2_MSG_CHANNEL_EXTENDED_DATA
&&
6795 ssh_pkt_getuint32(pktin
) != SSH2_EXTENDED_DATA_STDERR
)
6796 return; /* extended but not stderr */
6797 ssh_pkt_getstring(pktin
, &data
, &length
);
6800 c
->v
.v2
.locwindow
-= length
;
6801 c
->v
.v2
.remlocwin
-= length
;
6803 case CHAN_MAINSESSION
:
6805 from_backend(ssh
->frontend
, pktin
->type
==
6806 SSH2_MSG_CHANNEL_EXTENDED_DATA
,
6810 bufsize
= x11_send(c
->u
.x11
.s
, data
, length
);
6813 bufsize
= pfd_send(c
->u
.pfd
.s
, data
, length
);
6816 while (length
> 0) {
6817 if (c
->u
.a
.lensofar
< 4) {
6818 unsigned int l
= min(4 - c
->u
.a
.lensofar
,
6820 memcpy(c
->u
.a
.msglen
+ c
->u
.a
.lensofar
,
6824 c
->u
.a
.lensofar
+= l
;
6826 if (c
->u
.a
.lensofar
== 4) {
6828 4 + GET_32BIT(c
->u
.a
.msglen
);
6829 c
->u
.a
.message
= snewn(c
->u
.a
.totallen
,
6831 memcpy(c
->u
.a
.message
, c
->u
.a
.msglen
, 4);
6833 if (c
->u
.a
.lensofar
>= 4 && length
> 0) {
6835 min(c
->u
.a
.totallen
- c
->u
.a
.lensofar
,
6837 memcpy(c
->u
.a
.message
+ c
->u
.a
.lensofar
,
6841 c
->u
.a
.lensofar
+= l
;
6843 if (c
->u
.a
.lensofar
== c
->u
.a
.totallen
) {
6846 if (agent_query(c
->u
.a
.message
,
6849 ssh_agentf_callback
, c
))
6850 ssh_agentf_callback(c
, reply
, replylen
);
6851 sfree(c
->u
.a
.message
);
6852 c
->u
.a
.message
= NULL
;
6853 c
->u
.a
.lensofar
= 0;
6860 * If it looks like the remote end hit the end of its window,
6861 * and we didn't want it to do that, think about using a
6864 if (c
->v
.v2
.remlocwin
<= 0 && c
->v
.v2
.throttle_state
== UNTHROTTLED
&&
6865 c
->v
.v2
.locmaxwin
< 0x40000000)
6866 c
->v
.v2
.locmaxwin
+= OUR_V2_WINSIZE
;
6868 * If we are not buffering too much data,
6869 * enlarge the window again at the remote side.
6870 * If we are buffering too much, we may still
6871 * need to adjust the window if the server's
6874 ssh2_set_window(c
, bufsize
< c
->v
.v2
.locmaxwin ?
6875 c
->v
.v2
.locmaxwin
- bufsize
: 0);
6877 * If we're either buffering way too much data, or if we're
6878 * buffering anything at all and we're in "simple" mode,
6879 * throttle the whole channel.
6881 if ((bufsize
> c
->v
.v2
.locmaxwin
||
6882 (conf_get_int(ssh
->conf
, CONF_ssh_simple
) && bufsize
> 0)) &&
6883 !c
->throttling_conn
) {
6884 c
->throttling_conn
= 1;
6885 ssh_throttle_conn(ssh
, +1);
6890 static void ssh_channel_destroy(struct ssh_channel
*c
)
6895 case CHAN_MAINSESSION
:
6896 ssh
->mainchan
= NULL
;
6897 update_specials_menu(ssh
->frontend
);
6900 if (c
->u
.x11
.s
!= NULL
)
6901 x11_close(c
->u
.x11
.s
);
6902 logevent("Forwarded X11 connection terminated");
6905 sfree(c
->u
.a
.message
);
6908 if (c
->u
.pfd
.s
!= NULL
)
6909 pfd_close(c
->u
.pfd
.s
);
6910 logevent("Forwarded port closed");
6914 del234(ssh
->channels
, c
);
6915 if (ssh
->version
== 2) {
6916 bufchain_clear(&c
->v
.v2
.outbuffer
);
6917 assert(c
->v
.v2
.chanreq_head
== NULL
);
6922 * See if that was the last channel left open.
6923 * (This is only our termination condition if we're
6924 * not running in -N mode.)
6926 if (ssh
->version
== 2 &&
6927 !conf_get_int(ssh
->conf
, CONF_ssh_no_shell
) &&
6928 count234(ssh
->channels
) == 0) {
6930 * We used to send SSH_MSG_DISCONNECT here,
6931 * because I'd believed that _every_ conforming
6932 * SSH-2 connection had to end with a disconnect
6933 * being sent by at least one side; apparently
6934 * I was wrong and it's perfectly OK to
6935 * unceremoniously slam the connection shut
6936 * when you're done, and indeed OpenSSH feels
6937 * this is more polite than sending a
6938 * DISCONNECT. So now we don't.
6940 ssh_disconnect(ssh
, "All channels closed", NULL
, 0, TRUE
);
6944 static void ssh2_channel_check_close(struct ssh_channel
*c
)
6947 struct Packet
*pktout
;
6949 if ((c
->closes
& (CLOSES_SENT_EOF
| CLOSES_RCVD_EOF
| CLOSES_SENT_CLOSE
))
6950 == (CLOSES_SENT_EOF
| CLOSES_RCVD_EOF
) && !c
->v
.v2
.chanreq_head
) {
6952 * We have both sent and received EOF, and we have no
6953 * outstanding channel requests, which means the
6954 * channel is in final wind-up. But we haven't sent CLOSE, so
6957 pktout
= ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE
);
6958 ssh2_pkt_adduint32(pktout
, c
->remoteid
);
6959 ssh2_pkt_send(ssh
, pktout
);
6960 c
->closes
|= CLOSES_SENT_CLOSE
;
6963 if (!((CLOSES_SENT_CLOSE
| CLOSES_RCVD_CLOSE
) & ~c
->closes
)) {
6964 assert(c
->v
.v2
.chanreq_head
== NULL
);
6966 * We have both sent and received CLOSE, which means we're
6967 * completely done with the channel.
6969 ssh_channel_destroy(c
);
6973 static void ssh2_channel_got_eof(struct ssh_channel
*c
)
6975 if (c
->closes
& CLOSES_RCVD_EOF
)
6976 return; /* already seen EOF */
6977 c
->closes
|= CLOSES_RCVD_EOF
;
6979 if (c
->type
== CHAN_X11
) {
6980 x11_send_eof(c
->u
.x11
.s
);
6981 } else if (c
->type
== CHAN_AGENT
) {
6982 /* Manufacture an outgoing EOF in response to the incoming one. */
6983 sshfwd_write_eof(c
);
6984 } else if (c
->type
== CHAN_SOCKDATA
) {
6985 pfd_send_eof(c
->u
.pfd
.s
);
6986 } else if (c
->type
== CHAN_MAINSESSION
) {
6989 if (!ssh
->sent_console_eof
&&
6990 (from_backend_eof(ssh
->frontend
) || ssh
->got_pty
)) {
6992 * Either from_backend_eof told us that the front end
6993 * wants us to close the outgoing side of the connection
6994 * as soon as we see EOF from the far end, or else we've
6995 * unilaterally decided to do that because we've allocated
6996 * a remote pty and hence EOF isn't a particularly
6997 * meaningful concept.
6999 sshfwd_write_eof(c
);
7001 ssh
->sent_console_eof
= TRUE
;
7004 ssh2_channel_check_close(c
);
7007 static void ssh2_msg_channel_eof(Ssh ssh
, struct Packet
*pktin
)
7009 struct ssh_channel
*c
;
7011 c
= ssh2_channel_msg(ssh
, pktin
);
7014 ssh2_channel_got_eof(c
);
7017 static void ssh2_msg_channel_close(Ssh ssh
, struct Packet
*pktin
)
7019 struct ssh_channel
*c
;
7021 c
= ssh2_channel_msg(ssh
, pktin
);
7026 * When we receive CLOSE on a channel, we assume it comes with an
7027 * implied EOF if we haven't seen EOF yet.
7029 ssh2_channel_got_eof(c
);
7032 * And we also send an outgoing EOF, if we haven't already, on the
7033 * assumption that CLOSE is a pretty forceful announcement that
7034 * the remote side is doing away with the entire channel. (If it
7035 * had wanted to send us EOF and continue receiving data from us,
7036 * it would have just sent CHANNEL_EOF.)
7038 if (!(c
->closes
& CLOSES_SENT_EOF
)) {
7040 * Make sure we don't read any more from whatever our local
7041 * data source is for this channel.
7044 case CHAN_MAINSESSION
:
7045 ssh
->send_ok
= 0; /* stop trying to read from stdin */
7048 x11_override_throttle(c
->u
.x11
.s
, 1);
7051 pfd_override_throttle(c
->u
.pfd
.s
, 1);
7056 * Send outgoing EOF.
7058 sshfwd_write_eof(c
);
7062 * Now process the actual close.
7064 if (!(c
->closes
& CLOSES_RCVD_CLOSE
)) {
7065 c
->closes
|= CLOSES_RCVD_CLOSE
;
7066 ssh2_channel_check_close(c
);
7070 static void ssh2_msg_channel_open_confirmation(Ssh ssh
, struct Packet
*pktin
)
7072 struct ssh_channel
*c
;
7074 c
= ssh2_channel_msg(ssh
, pktin
);
7077 if (c
->type
!= CHAN_SOCKDATA_DORMANT
)
7078 return; /* dunno why they're confirming this */
7079 c
->remoteid
= ssh_pkt_getuint32(pktin
);
7080 c
->halfopen
= FALSE
;
7081 c
->type
= CHAN_SOCKDATA
;
7082 c
->v
.v2
.remwindow
= ssh_pkt_getuint32(pktin
);
7083 c
->v
.v2
.remmaxpkt
= ssh_pkt_getuint32(pktin
);
7085 pfd_confirm(c
->u
.pfd
.s
);
7087 ssh_channel_try_eof(c
);
7090 static void ssh2_msg_channel_open_failure(Ssh ssh
, struct Packet
*pktin
)
7092 static const char *const reasons
[] = {
7093 "<unknown reason code>",
7094 "Administratively prohibited",
7096 "Unknown channel type",
7097 "Resource shortage",
7099 unsigned reason_code
;
7100 char *reason_string
;
7102 struct ssh_channel
*c
;
7103 c
= ssh2_channel_msg(ssh
, pktin
);
7106 if (c
->type
!= CHAN_SOCKDATA_DORMANT
)
7107 return; /* dunno why they're failing this */
7109 reason_code
= ssh_pkt_getuint32(pktin
);
7110 if (reason_code
>= lenof(reasons
))
7111 reason_code
= 0; /* ensure reasons[reason_code] in range */
7112 ssh_pkt_getstring(pktin
, &reason_string
, &reason_length
);
7113 logeventf(ssh
, "Forwarded connection refused by server: %s [%.*s]",
7114 reasons
[reason_code
], reason_length
, reason_string
);
7116 pfd_close(c
->u
.pfd
.s
);
7118 del234(ssh
->channels
, c
);
7122 static void ssh2_msg_channel_request(Ssh ssh
, struct Packet
*pktin
)
7125 int typelen
, want_reply
;
7126 int reply
= SSH2_MSG_CHANNEL_FAILURE
; /* default */
7127 struct ssh_channel
*c
;
7128 struct Packet
*pktout
;
7130 c
= ssh2_channel_msg(ssh
, pktin
);
7133 ssh_pkt_getstring(pktin
, &type
, &typelen
);
7134 want_reply
= ssh2_pkt_getbool(pktin
);
7137 * Having got the channel number, we now look at
7138 * the request type string to see if it's something
7141 if (c
== ssh
->mainchan
) {
7143 * We recognise "exit-status" and "exit-signal" on
7144 * the primary channel.
7146 if (typelen
== 11 &&
7147 !memcmp(type
, "exit-status", 11)) {
7149 ssh
->exitcode
= ssh_pkt_getuint32(pktin
);
7150 logeventf(ssh
, "Server sent command exit status %d",
7152 reply
= SSH2_MSG_CHANNEL_SUCCESS
;
7154 } else if (typelen
== 11 &&
7155 !memcmp(type
, "exit-signal", 11)) {
7157 int is_plausible
= TRUE
, is_int
= FALSE
;
7158 char *fmt_sig
= "", *fmt_msg
= "";
7160 int msglen
= 0, core
= FALSE
;
7161 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
7162 * provide an `int' for the signal, despite its
7163 * having been a `string' in the drafts of RFC 4254 since at
7164 * least 2001. (Fixed in session.c 1.147.) Try to
7165 * infer which we can safely parse it as. */
7167 unsigned char *p
= pktin
->body
+
7169 long len
= pktin
->length
- pktin
->savedpos
;
7170 unsigned long num
= GET_32BIT(p
); /* what is it? */
7171 /* If it's 0, it hardly matters; assume string */
7175 int maybe_int
= FALSE
, maybe_str
= FALSE
;
7176 #define CHECK_HYPOTHESIS(offset, result) \
7179 if (q >= 0 && q+4 <= len) { \
7180 q = q + 4 + GET_32BIT(p+q); \
7181 if (q >= 0 && q+4 <= len && \
7182 ((q = q + 4 + GET_32BIT(p+q))!= 0) && q == len) \
7186 CHECK_HYPOTHESIS(4+1, maybe_int
);
7187 CHECK_HYPOTHESIS(4+num
+1, maybe_str
);
7188 #undef CHECK_HYPOTHESIS
7189 if (maybe_int
&& !maybe_str
)
7191 else if (!maybe_int
&& maybe_str
)
7194 /* Crikey. Either or neither. Panic. */
7195 is_plausible
= FALSE
;
7198 ssh
->exitcode
= 128; /* means `unknown signal' */
7201 /* Old non-standard OpenSSH. */
7202 int signum
= ssh_pkt_getuint32(pktin
);
7203 fmt_sig
= dupprintf(" %d", signum
);
7204 ssh
->exitcode
= 128 + signum
;
7206 /* As per RFC 4254. */
7209 ssh_pkt_getstring(pktin
, &sig
, &siglen
);
7210 /* Signal name isn't supposed to be blank, but
7211 * let's cope gracefully if it is. */
7213 fmt_sig
= dupprintf(" \"%.*s\"",
7218 * Really hideous method of translating the
7219 * signal description back into a locally
7220 * meaningful number.
7225 #define TRANSLATE_SIGNAL(s) \
7226 else if (siglen == lenof(#s)-1 && !memcmp(sig, #s, siglen)) \
7227 ssh->exitcode = 128 + SIG ## s
7229 TRANSLATE_SIGNAL(ABRT
);
7232 TRANSLATE_SIGNAL(ALRM
);
7235 TRANSLATE_SIGNAL(FPE
);
7238 TRANSLATE_SIGNAL(HUP
);
7241 TRANSLATE_SIGNAL(ILL
);
7244 TRANSLATE_SIGNAL(INT
);
7247 TRANSLATE_SIGNAL(KILL
);
7250 TRANSLATE_SIGNAL(PIPE
);
7253 TRANSLATE_SIGNAL(QUIT
);
7256 TRANSLATE_SIGNAL(SEGV
);
7259 TRANSLATE_SIGNAL(TERM
);
7262 TRANSLATE_SIGNAL(USR1
);
7265 TRANSLATE_SIGNAL(USR2
);
7267 #undef TRANSLATE_SIGNAL
7269 ssh
->exitcode
= 128;
7271 core
= ssh2_pkt_getbool(pktin
);
7272 ssh_pkt_getstring(pktin
, &msg
, &msglen
);
7274 fmt_msg
= dupprintf(" (\"%.*s\")", msglen
, msg
);
7276 /* ignore lang tag */
7277 } /* else don't attempt to parse */
7278 logeventf(ssh
, "Server exited on signal%s%s%s",
7279 fmt_sig
, core ?
" (core dumped)" : "",
7281 if (*fmt_sig
) sfree(fmt_sig
);
7282 if (*fmt_msg
) sfree(fmt_msg
);
7283 reply
= SSH2_MSG_CHANNEL_SUCCESS
;
7288 * This is a channel request we don't know
7289 * about, so we now either ignore the request
7290 * or respond with CHANNEL_FAILURE, depending
7293 reply
= SSH2_MSG_CHANNEL_FAILURE
;
7296 pktout
= ssh2_pkt_init(reply
);
7297 ssh2_pkt_adduint32(pktout
, c
->remoteid
);
7298 ssh2_pkt_send(ssh
, pktout
);
7302 static void ssh2_msg_global_request(Ssh ssh
, struct Packet
*pktin
)
7305 int typelen
, want_reply
;
7306 struct Packet
*pktout
;
7308 ssh_pkt_getstring(pktin
, &type
, &typelen
);
7309 want_reply
= ssh2_pkt_getbool(pktin
);
7312 * We currently don't support any global requests
7313 * at all, so we either ignore the request or
7314 * respond with REQUEST_FAILURE, depending on
7318 pktout
= ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE
);
7319 ssh2_pkt_send(ssh
, pktout
);
7323 static void ssh2_msg_channel_open(Ssh ssh
, struct Packet
*pktin
)
7331 struct ssh_channel
*c
;
7332 unsigned remid
, winsize
, pktsize
;
7333 struct Packet
*pktout
;
7335 ssh_pkt_getstring(pktin
, &type
, &typelen
);
7336 c
= snew(struct ssh_channel
);
7339 remid
= ssh_pkt_getuint32(pktin
);
7340 winsize
= ssh_pkt_getuint32(pktin
);
7341 pktsize
= ssh_pkt_getuint32(pktin
);
7343 if (typelen
== 3 && !memcmp(type
, "x11", 3)) {
7347 ssh_pkt_getstring(pktin
, &peeraddr
, &peeraddrlen
);
7348 addrstr
= snewn(peeraddrlen
+1, char);
7349 memcpy(addrstr
, peeraddr
, peeraddrlen
);
7350 addrstr
[peeraddrlen
] = '\0';
7351 peerport
= ssh_pkt_getuint32(pktin
);
7353 logeventf(ssh
, "Received X11 connect request from %s:%d",
7356 if (!ssh
->X11_fwd_enabled
)
7357 error
= "X11 forwarding is not enabled";
7358 else if ((x11err
= x11_init(&c
->u
.x11
.s
, ssh
->x11disp
, c
,
7359 addrstr
, peerport
, ssh
->conf
)) != NULL
) {
7360 logeventf(ssh
, "Local X11 connection failed: %s", x11err
);
7361 error
= "Unable to open an X11 connection";
7363 logevent("Opening X11 forward connection succeeded");
7368 } else if (typelen
== 15 &&
7369 !memcmp(type
, "forwarded-tcpip", 15)) {
7370 struct ssh_rportfwd pf
, *realpf
;
7373 ssh_pkt_getstring(pktin
, &dummy
, &dummylen
);/* skip address */
7374 pf
.sport
= ssh_pkt_getuint32(pktin
);
7375 ssh_pkt_getstring(pktin
, &peeraddr
, &peeraddrlen
);
7376 peerport
= ssh_pkt_getuint32(pktin
);
7377 realpf
= find234(ssh
->rportfwds
, &pf
, NULL
);
7378 logeventf(ssh
, "Received remote port %d open request "
7379 "from %s:%d", pf
.sport
, peeraddr
, peerport
);
7380 if (realpf
== NULL
) {
7381 error
= "Remote port is not recognised";
7383 const char *e
= pfd_newconnect(&c
->u
.pfd
.s
,
7387 realpf
->pfrec
->addressfamily
);
7388 logeventf(ssh
, "Attempting to forward remote port to "
7389 "%s:%d", realpf
->dhost
, realpf
->dport
);
7391 logeventf(ssh
, "Port open failed: %s", e
);
7392 error
= "Port open failed";
7394 logevent("Forwarded port opened successfully");
7395 c
->type
= CHAN_SOCKDATA
;
7398 } else if (typelen
== 22 &&
7399 !memcmp(type
, "auth-agent@openssh.com", 22)) {
7400 if (!ssh
->agentfwd_enabled
)
7401 error
= "Agent forwarding is not enabled";
7403 c
->type
= CHAN_AGENT
; /* identify channel type */
7404 c
->u
.a
.lensofar
= 0;
7407 error
= "Unsupported channel type requested";
7410 c
->remoteid
= remid
;
7411 c
->halfopen
= FALSE
;
7413 pktout
= ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE
);
7414 ssh2_pkt_adduint32(pktout
, c
->remoteid
);
7415 ssh2_pkt_adduint32(pktout
, SSH2_OPEN_CONNECT_FAILED
);
7416 ssh2_pkt_addstring(pktout
, error
);
7417 ssh2_pkt_addstring(pktout
, "en"); /* language tag */
7418 ssh2_pkt_send(ssh
, pktout
);
7419 logeventf(ssh
, "Rejected channel open: %s", error
);
7422 ssh2_channel_init(c
);
7423 c
->v
.v2
.remwindow
= winsize
;
7424 c
->v
.v2
.remmaxpkt
= pktsize
;
7425 add234(ssh
->channels
, c
);
7426 pktout
= ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
);
7427 ssh2_pkt_adduint32(pktout
, c
->remoteid
);
7428 ssh2_pkt_adduint32(pktout
, c
->localid
);
7429 ssh2_pkt_adduint32(pktout
, c
->v
.v2
.locwindow
);
7430 ssh2_pkt_adduint32(pktout
, OUR_V2_MAXPKT
); /* our max pkt size */
7431 ssh2_pkt_send(ssh
, pktout
);
7436 * Buffer banner messages for later display at some convenient point,
7437 * if we're going to display them.
7439 static void ssh2_msg_userauth_banner(Ssh ssh
, struct Packet
*pktin
)
7441 /* Arbitrary limit to prevent unbounded inflation of buffer */
7442 if (conf_get_int(ssh
->conf
, CONF_ssh_show_banner
) &&
7443 bufchain_size(&ssh
->banner
) <= 131072) {
7444 char *banner
= NULL
;
7446 ssh_pkt_getstring(pktin
, &banner
, &size
);
7448 bufchain_add(&ssh
->banner
, banner
, size
);
7452 /* Helper function to deal with sending tty modes for "pty-req" */
7453 static void ssh2_send_ttymode(void *data
, char *mode
, char *val
)
7455 struct Packet
*pktout
= (struct Packet
*)data
;
7457 unsigned int arg
= 0;
7458 while (strcmp(mode
, ssh_ttymodes
[i
].mode
) != 0) i
++;
7459 if (i
== lenof(ssh_ttymodes
)) return;
7460 switch (ssh_ttymodes
[i
].type
) {
7462 arg
= ssh_tty_parse_specchar(val
);
7465 arg
= ssh_tty_parse_boolean(val
);
7468 ssh2_pkt_addbyte(pktout
, ssh_ttymodes
[i
].opcode
);
7469 ssh2_pkt_adduint32(pktout
, arg
);
7472 static void ssh2_maybe_setup_x11(struct ssh_channel
*c
, struct Packet
*pktin
,
7475 struct ssh2_maybe_setup_x11_state
{
7479 struct Packet
*pktout
;
7480 crStateP(ssh2_maybe_setup_x11_state
, ctx
);
7485 * Potentially enable X11 forwarding.
7487 if (ssh
->mainchan
&& !ssh
->ncmode
&& conf_get_int(ssh
->conf
, CONF_x11_forward
) &&
7488 (ssh
->x11disp
= x11_setup_display(conf_get_str(ssh
->conf
, CONF_x11_display
),
7489 conf_get_int(ssh
->conf
, CONF_x11_auth
), ssh
->conf
))) {
7490 logevent("Requesting X11 forwarding");
7491 pktout
= ssh2_chanreq_init(ssh
->mainchan
, "x11-req",
7492 ssh2_maybe_setup_x11
, s
);
7493 ssh2_pkt_addbool(pktout
, 0); /* many connections */
7494 ssh2_pkt_addstring(pktout
, ssh
->x11disp
->remoteauthprotoname
);
7496 * Note that while we blank the X authentication data here, we don't
7497 * take any special action to blank the start of an X11 channel,
7498 * so using MIT-MAGIC-COOKIE-1 and actually opening an X connection
7499 * without having session blanking enabled is likely to leak your
7500 * cookie into the log.
7502 dont_log_password(ssh
, pktout
, PKTLOG_BLANK
);
7503 ssh2_pkt_addstring(pktout
, ssh
->x11disp
->remoteauthdatastring
);
7504 end_log_omission(ssh
, pktout
);
7505 ssh2_pkt_adduint32(pktout
, ssh
->x11disp
->screennum
);
7506 ssh2_pkt_send(ssh
, pktout
);
7508 crWaitUntilV(pktin
);
7511 if (pktin
->type
== SSH2_MSG_CHANNEL_SUCCESS
) {
7512 logevent("X11 forwarding enabled");
7513 ssh
->X11_fwd_enabled
= TRUE
;
7515 logevent("X11 forwarding refused");
7521 static void ssh2_maybe_setup_agent(struct ssh_channel
*c
, struct Packet
*pktin
,
7524 struct ssh2_maybe_setup_agent_state
{
7528 struct Packet
*pktout
;
7529 crStateP(ssh2_maybe_setup_agent_state
, ctx
);
7533 if (ssh
->mainchan
&& !ssh
->ncmode
&& conf_get_int(ssh
->conf
, CONF_agentfwd
) && agent_exists()) {
7534 logevent("Requesting OpenSSH-style agent forwarding");
7535 pktout
= ssh2_chanreq_init(ssh
->mainchan
, "auth-agent-req@openssh.com",
7536 ssh2_maybe_setup_agent
, s
);
7537 ssh2_pkt_send(ssh
, pktout
);
7539 crWaitUntilV(pktin
);
7542 if (pktin
->type
== SSH2_MSG_CHANNEL_SUCCESS
) {
7543 logevent("Agent forwarding enabled");
7544 ssh
->agentfwd_enabled
= TRUE
;
7546 logevent("Agent forwarding refused");
7552 static void ssh2_maybe_setup_pty(struct ssh_channel
*c
, struct Packet
*pktin
,
7555 struct ssh2_maybe_setup_pty_state
{
7559 struct Packet
*pktout
;
7560 crStateP(ssh2_maybe_setup_pty_state
, ctx
);
7564 if (ssh
->mainchan
&& !ssh
->ncmode
&& !conf_get_int(ssh
->conf
, CONF_nopty
)) {
7565 /* Unpick the terminal-speed string. */
7566 /* XXX perhaps we should allow no speeds to be sent. */
7567 ssh
->ospeed
= 38400; ssh
->ispeed
= 38400; /* last-resort defaults */
7568 sscanf(conf_get_str(ssh
->conf
, CONF_termspeed
), "%d,%d", &ssh
->ospeed
, &ssh
->ispeed
);
7569 /* Build the pty request. */
7570 pktout
= ssh2_chanreq_init(ssh
->mainchan
, "pty-req",
7571 ssh2_maybe_setup_pty
, s
);
7572 ssh2_pkt_addstring(pktout
, conf_get_str(ssh
->conf
, CONF_termtype
));
7573 ssh2_pkt_adduint32(pktout
, ssh
->term_width
);
7574 ssh2_pkt_adduint32(pktout
, ssh
->term_height
);
7575 ssh2_pkt_adduint32(pktout
, 0); /* pixel width */
7576 ssh2_pkt_adduint32(pktout
, 0); /* pixel height */
7577 ssh2_pkt_addstring_start(pktout
);
7578 parse_ttymodes(ssh
, ssh2_send_ttymode
, (void *)pktout
);
7579 ssh2_pkt_addbyte(pktout
, SSH2_TTY_OP_ISPEED
);
7580 ssh2_pkt_adduint32(pktout
, ssh
->ispeed
);
7581 ssh2_pkt_addbyte(pktout
, SSH2_TTY_OP_OSPEED
);
7582 ssh2_pkt_adduint32(pktout
, ssh
->ospeed
);
7583 ssh2_pkt_addstring_data(pktout
, "\0", 1); /* TTY_OP_END */
7584 ssh2_pkt_send(ssh
, pktout
);
7585 ssh
->state
= SSH_STATE_INTERMED
;
7587 crWaitUntilV(pktin
);
7590 if (pktin
->type
== SSH2_MSG_CHANNEL_SUCCESS
) {
7591 logeventf(ssh
, "Allocated pty (ospeed %dbps, ispeed %dbps)",
7592 ssh
->ospeed
, ssh
->ispeed
);
7593 ssh
->got_pty
= TRUE
;
7595 c_write_str(ssh
, "Server refused to allocate pty\r\n");
7596 ssh
->editing
= ssh
->echoing
= 1;
7600 ssh
->editing
= ssh
->echoing
= 1;
7605 static void ssh2_setup_env(struct ssh_channel
*c
, struct Packet
*pktin
,
7608 struct ssh2_setup_env_state
{
7610 int num_env
, env_left
, env_ok
;
7613 struct Packet
*pktout
;
7614 crStateP(ssh2_setup_env_state
, ctx
);
7619 * Send environment variables.
7621 * Simplest thing here is to send all the requests at once, and
7622 * then wait for a whole bunch of successes or failures.
7625 if (ssh
->mainchan
&& !ssh
->ncmode
) {
7628 for (val
= conf_get_str_strs(ssh
->conf
, CONF_environmt
, NULL
, &key
);
7630 val
= conf_get_str_strs(ssh
->conf
, CONF_environmt
, key
, &key
)) {
7631 pktout
= ssh2_chanreq_init(ssh
->mainchan
, "env", ssh2_setup_env
, s
);
7632 ssh2_pkt_addstring(pktout
, key
);
7633 ssh2_pkt_addstring(pktout
, val
);
7634 ssh2_pkt_send(ssh
, pktout
);
7639 logeventf(ssh
, "Sent %d environment variables", s
->num_env
);
7644 s
->env_left
= s
->num_env
;
7646 while (s
->env_left
> 0) {
7647 crWaitUntilV(pktin
);
7648 if (!pktin
) goto out
;
7649 if (pktin
->type
== SSH2_MSG_CHANNEL_SUCCESS
)
7654 if (s
->env_ok
== s
->num_env
) {
7655 logevent("All environment variables successfully set");
7656 } else if (s
->env_ok
== 0) {
7657 logevent("All environment variables refused");
7658 c_write_str(ssh
, "Server refused to set environment variables\r\n");
7660 logeventf(ssh
, "%d environment variables refused",
7661 s
->num_env
- s
->env_ok
);
7662 c_write_str(ssh
, "Server refused to set all environment variables\r\n");
7670 * Handle the SSH-2 userauth and connection layers.
7672 static void ssh2_msg_authconn(Ssh ssh
, struct Packet
*pktin
)
7674 do_ssh2_authconn(ssh
, NULL
, 0, pktin
);
7677 static void ssh2_response_authconn(struct ssh_channel
*c
, struct Packet
*pktin
,
7680 do_ssh2_authconn(c
->ssh
, NULL
, 0, pktin
);
7683 static void do_ssh2_authconn(Ssh ssh
, unsigned char *in
, int inlen
,
7684 struct Packet
*pktin
)
7686 struct do_ssh2_authconn_state
{
7690 AUTH_TYPE_PUBLICKEY
,
7691 AUTH_TYPE_PUBLICKEY_OFFER_LOUD
,
7692 AUTH_TYPE_PUBLICKEY_OFFER_QUIET
,
7694 AUTH_TYPE_GSSAPI
, /* always QUIET */
7695 AUTH_TYPE_KEYBOARD_INTERACTIVE
,
7696 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
7698 int done_service_req
;
7699 int gotit
, need_pw
, can_pubkey
, can_passwd
, can_keyb_inter
;
7700 int tried_pubkey_config
, done_agent
;
7705 int kbd_inter_refused
;
7706 int we_are_in
, userauth_success
;
7707 prompts_t
*cur_prompt
;
7712 void *publickey_blob
;
7713 int publickey_bloblen
;
7714 int publickey_encrypted
;
7715 char *publickey_algorithm
;
7716 char *publickey_comment
;
7717 unsigned char agent_request
[5], *agent_response
, *agentp
;
7718 int agent_responselen
;
7719 unsigned char *pkblob_in_agent
;
7721 char *pkblob
, *alg
, *commentp
;
7722 int pklen
, alglen
, commentlen
;
7723 int siglen
, retlen
, len
;
7724 char *q
, *agentreq
, *ret
;
7726 struct Packet
*pktout
;
7729 struct ssh_gss_library
*gsslib
;
7730 Ssh_gss_ctx gss_ctx
;
7731 Ssh_gss_buf gss_buf
;
7732 Ssh_gss_buf gss_rcvtok
, gss_sndtok
;
7733 Ssh_gss_name gss_srv_name
;
7734 Ssh_gss_stat gss_stat
;
7737 crState(do_ssh2_authconn_state
);
7741 /* Register as a handler for all the messages this coroutine handles. */
7742 ssh
->packet_dispatch
[SSH2_MSG_SERVICE_ACCEPT
] = ssh2_msg_authconn
;
7743 ssh
->packet_dispatch
[SSH2_MSG_USERAUTH_REQUEST
] = ssh2_msg_authconn
;
7744 ssh
->packet_dispatch
[SSH2_MSG_USERAUTH_FAILURE
] = ssh2_msg_authconn
;
7745 ssh
->packet_dispatch
[SSH2_MSG_USERAUTH_SUCCESS
] = ssh2_msg_authconn
;
7746 ssh
->packet_dispatch
[SSH2_MSG_USERAUTH_BANNER
] = ssh2_msg_authconn
;
7747 ssh
->packet_dispatch
[SSH2_MSG_USERAUTH_PK_OK
] = ssh2_msg_authconn
;
7748 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = ssh2_msg_authconn; duplicate case value */
7749 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = ssh2_msg_authconn; duplicate case value */
7750 ssh
->packet_dispatch
[SSH2_MSG_USERAUTH_INFO_RESPONSE
] = ssh2_msg_authconn
;
7751 ssh
->packet_dispatch
[SSH2_MSG_GLOBAL_REQUEST
] = ssh2_msg_authconn
;
7752 ssh
->packet_dispatch
[SSH2_MSG_REQUEST_SUCCESS
] = ssh2_msg_authconn
;
7753 ssh
->packet_dispatch
[SSH2_MSG_REQUEST_FAILURE
] = ssh2_msg_authconn
;
7754 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_OPEN
] = ssh2_msg_authconn
;
7755 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
] = ssh2_msg_authconn
;
7756 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_OPEN_FAILURE
] = ssh2_msg_authconn
;
7757 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_WINDOW_ADJUST
] = ssh2_msg_authconn
;
7758 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_DATA
] = ssh2_msg_authconn
;
7759 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_EXTENDED_DATA
] = ssh2_msg_authconn
;
7760 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_EOF
] = ssh2_msg_authconn
;
7761 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_CLOSE
] = ssh2_msg_authconn
;
7763 s
->done_service_req
= FALSE
;
7764 s
->we_are_in
= s
->userauth_success
= FALSE
;
7766 s
->tried_gssapi
= FALSE
;
7769 if (!conf_get_int(ssh
->conf
, CONF_ssh_no_userauth
)) {
7771 * Request userauth protocol, and await a response to it.
7773 s
->pktout
= ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST
);
7774 ssh2_pkt_addstring(s
->pktout
, "ssh-userauth");
7775 ssh2_pkt_send(ssh
, s
->pktout
);
7776 crWaitUntilV(pktin
);
7777 if (pktin
->type
== SSH2_MSG_SERVICE_ACCEPT
)
7778 s
->done_service_req
= TRUE
;
7780 if (!s
->done_service_req
) {
7782 * Request connection protocol directly, without authentication.
7784 s
->pktout
= ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST
);
7785 ssh2_pkt_addstring(s
->pktout
, "ssh-connection");
7786 ssh2_pkt_send(ssh
, s
->pktout
);
7787 crWaitUntilV(pktin
);
7788 if (pktin
->type
== SSH2_MSG_SERVICE_ACCEPT
) {
7789 s
->we_are_in
= TRUE
; /* no auth required */
7791 bombout(("Server refused service request"));
7796 /* Arrange to be able to deal with any BANNERs that come in.
7797 * (We do this now as packets may come in during the next bit.) */
7798 bufchain_init(&ssh
->banner
);
7799 ssh
->packet_dispatch
[SSH2_MSG_USERAUTH_BANNER
] =
7800 ssh2_msg_userauth_banner
;
7803 * Misc one-time setup for authentication.
7805 s
->publickey_blob
= NULL
;
7806 if (!s
->we_are_in
) {
7809 * Load the public half of any configured public key file
7812 s
->keyfile
= conf_get_filename(ssh
->conf
, CONF_keyfile
);
7813 if (!filename_is_null(s
->keyfile
)) {
7815 logeventf(ssh
, "Reading private key file \"%.150s\"",
7816 filename_to_str(s
->keyfile
));
7817 keytype
= key_type(s
->keyfile
);
7818 if (keytype
== SSH_KEYTYPE_SSH2
) {
7821 ssh2_userkey_loadpub(s
->keyfile
,
7822 &s
->publickey_algorithm
,
7823 &s
->publickey_bloblen
,
7824 &s
->publickey_comment
, &error
);
7825 if (s
->publickey_blob
) {
7826 s
->publickey_encrypted
=
7827 ssh2_userkey_encrypted(s
->keyfile
, NULL
);
7830 logeventf(ssh
, "Unable to load private key (%s)",
7832 msgbuf
= dupprintf("Unable to load private key file "
7833 "\"%.150s\" (%s)\r\n",
7834 filename_to_str(s
->keyfile
),
7836 c_write_str(ssh
, msgbuf
);
7841 logeventf(ssh
, "Unable to use this key file (%s)",
7842 key_type_to_str(keytype
));
7843 msgbuf
= dupprintf("Unable to use key file \"%.150s\""
7845 filename_to_str(s
->keyfile
),
7846 key_type_to_str(keytype
));
7847 c_write_str(ssh
, msgbuf
);
7849 s
->publickey_blob
= NULL
;
7854 * Find out about any keys Pageant has (but if there's a
7855 * public key configured, filter out all others).
7858 s
->agent_response
= NULL
;
7859 s
->pkblob_in_agent
= NULL
;
7860 if (conf_get_int(ssh
->conf
, CONF_tryagent
) && agent_exists()) {
7864 logevent("Pageant is running. Requesting keys.");
7866 /* Request the keys held by the agent. */
7867 PUT_32BIT(s
->agent_request
, 1);
7868 s
->agent_request
[4] = SSH2_AGENTC_REQUEST_IDENTITIES
;
7869 if (!agent_query(s
->agent_request
, 5, &r
, &s
->agent_responselen
,
7870 ssh_agent_callback
, ssh
)) {
7874 bombout(("Unexpected data from server while"
7875 " waiting for agent response"));
7878 } while (pktin
|| inlen
> 0);
7879 r
= ssh
->agent_response
;
7880 s
->agent_responselen
= ssh
->agent_response_len
;
7882 s
->agent_response
= (unsigned char *) r
;
7883 if (s
->agent_response
&& s
->agent_responselen
>= 5 &&
7884 s
->agent_response
[4] == SSH2_AGENT_IDENTITIES_ANSWER
) {
7887 p
= s
->agent_response
+ 5;
7888 s
->nkeys
= GET_32BIT(p
);
7890 logeventf(ssh
, "Pageant has %d SSH-2 keys", s
->nkeys
);
7891 if (s
->publickey_blob
) {
7892 /* See if configured key is in agent. */
7893 for (keyi
= 0; keyi
< s
->nkeys
; keyi
++) {
7894 s
->pklen
= GET_32BIT(p
);
7895 if (s
->pklen
== s
->publickey_bloblen
&&
7896 !memcmp(p
+4, s
->publickey_blob
,
7897 s
->publickey_bloblen
)) {
7898 logeventf(ssh
, "Pageant key #%d matches "
7899 "configured key file", keyi
);
7901 s
->pkblob_in_agent
= p
;
7905 p
+= GET_32BIT(p
) + 4; /* comment */
7907 if (!s
->pkblob_in_agent
) {
7908 logevent("Configured key file not in Pageant");
7913 logevent("Failed to get reply from Pageant");
7920 * We repeat this whole loop, including the username prompt,
7921 * until we manage a successful authentication. If the user
7922 * types the wrong _password_, they can be sent back to the
7923 * beginning to try another username, if this is configured on.
7924 * (If they specify a username in the config, they are never
7925 * asked, even if they do give a wrong password.)
7927 * I think this best serves the needs of
7929 * - the people who have no configuration, no keys, and just
7930 * want to try repeated (username,password) pairs until they
7931 * type both correctly
7933 * - people who have keys and configuration but occasionally
7934 * need to fall back to passwords
7936 * - people with a key held in Pageant, who might not have
7937 * logged in to a particular machine before; so they want to
7938 * type a username, and then _either_ their key will be
7939 * accepted, _or_ they will type a password. If they mistype
7940 * the username they will want to be able to get back and
7943 s
->got_username
= FALSE
;
7944 while (!s
->we_are_in
) {
7948 if (s
->got_username
&& !conf_get_int(ssh
->conf
, CONF_change_username
)) {
7950 * We got a username last time round this loop, and
7951 * with change_username turned off we don't try to get
7954 } else if ((ssh
->username
= get_remote_username(ssh
->conf
)) == NULL
) {
7955 int ret
; /* need not be kept over crReturn */
7956 s
->cur_prompt
= new_prompts(ssh
->frontend
);
7957 s
->cur_prompt
->to_server
= TRUE
;
7958 s
->cur_prompt
->name
= dupstr("SSH login name");
7959 add_prompt(s
->cur_prompt
, dupstr("login as: "), TRUE
);
7960 ret
= get_userpass_input(s
->cur_prompt
, NULL
, 0);
7963 crWaitUntilV(!pktin
);
7964 ret
= get_userpass_input(s
->cur_prompt
, in
, inlen
);
7969 * get_userpass_input() failed to get a username.
7972 free_prompts(s
->cur_prompt
);
7973 ssh_disconnect(ssh
, "No username provided", NULL
, 0, TRUE
);
7976 ssh
->username
= dupstr(s
->cur_prompt
->prompts
[0]->result
);
7977 free_prompts(s
->cur_prompt
);
7980 if ((flags
& FLAG_VERBOSE
) || (flags
& FLAG_INTERACTIVE
)) {
7981 stuff
= dupprintf("Using username \"%s\".\r\n", ssh
->username
);
7982 c_write_str(ssh
, stuff
);
7986 s
->got_username
= TRUE
;
7989 * Send an authentication request using method "none": (a)
7990 * just in case it succeeds, and (b) so that we know what
7991 * authentication methods we can usefully try next.
7993 ssh
->pkt_actx
= SSH2_PKTCTX_NOAUTH
;
7995 s
->pktout
= ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
7996 ssh2_pkt_addstring(s
->pktout
, ssh
->username
);
7997 ssh2_pkt_addstring(s
->pktout
, "ssh-connection");/* service requested */
7998 ssh2_pkt_addstring(s
->pktout
, "none"); /* method */
7999 ssh2_pkt_send(ssh
, s
->pktout
);
8000 s
->type
= AUTH_TYPE_NONE
;
8002 s
->we_are_in
= FALSE
;
8004 s
->tried_pubkey_config
= FALSE
;
8005 s
->kbd_inter_refused
= FALSE
;
8007 /* Reset agent request state. */
8008 s
->done_agent
= FALSE
;
8009 if (s
->agent_response
) {
8010 if (s
->pkblob_in_agent
) {
8011 s
->agentp
= s
->pkblob_in_agent
;
8013 s
->agentp
= s
->agent_response
+ 5 + 4;
8019 char *methods
= NULL
;
8023 * Wait for the result of the last authentication request.
8026 crWaitUntilV(pktin
);
8028 * Now is a convenient point to spew any banner material
8029 * that we've accumulated. (This should ensure that when
8030 * we exit the auth loop, we haven't any left to deal
8034 int size
= bufchain_size(&ssh
->banner
);
8036 * Don't show the banner if we're operating in
8037 * non-verbose non-interactive mode. (It's probably
8038 * a script, which means nobody will read the
8039 * banner _anyway_, and moreover the printing of
8040 * the banner will screw up processing on the
8041 * output of (say) plink.)
8043 if (size
&& (flags
& (FLAG_VERBOSE
| FLAG_INTERACTIVE
))) {
8044 char *banner
= snewn(size
, char);
8045 bufchain_fetch(&ssh
->banner
, banner
, size
);
8046 c_write_untrusted(ssh
, banner
, size
);
8049 bufchain_clear(&ssh
->banner
);
8051 if (pktin
->type
== SSH2_MSG_USERAUTH_SUCCESS
) {
8052 logevent("Access granted");
8053 s
->we_are_in
= s
->userauth_success
= TRUE
;
8057 if (pktin
->type
!= SSH2_MSG_USERAUTH_FAILURE
&& s
->type
!= AUTH_TYPE_GSSAPI
) {
8058 bombout(("Strange packet received during authentication: "
8059 "type %d", pktin
->type
));
8066 * OK, we're now sitting on a USERAUTH_FAILURE message, so
8067 * we can look at the string in it and know what we can
8068 * helpfully try next.
8070 if (pktin
->type
== SSH2_MSG_USERAUTH_FAILURE
) {
8071 ssh_pkt_getstring(pktin
, &methods
, &methlen
);
8072 if (!ssh2_pkt_getbool(pktin
)) {
8074 * We have received an unequivocal Access
8075 * Denied. This can translate to a variety of
8076 * messages, or no message at all.
8078 * For forms of authentication which are attempted
8079 * implicitly, by which I mean without printing
8080 * anything in the window indicating that we're
8081 * trying them, we should never print 'Access
8084 * If we do print a message saying that we're
8085 * attempting some kind of authentication, it's OK
8086 * to print a followup message saying it failed -
8087 * but the message may sometimes be more specific
8088 * than simply 'Access denied'.
8090 * Additionally, if we'd just tried password
8091 * authentication, we should break out of this
8092 * whole loop so as to go back to the username
8093 * prompt (iff we're configured to allow
8094 * username change attempts).
8096 if (s
->type
== AUTH_TYPE_NONE
) {
8098 } else if (s
->type
== AUTH_TYPE_PUBLICKEY_OFFER_LOUD
||
8099 s
->type
== AUTH_TYPE_PUBLICKEY_OFFER_QUIET
) {
8100 if (s
->type
== AUTH_TYPE_PUBLICKEY_OFFER_LOUD
)
8101 c_write_str(ssh
, "Server refused our key\r\n");
8102 logevent("Server refused our key");
8103 } else if (s
->type
== AUTH_TYPE_PUBLICKEY
) {
8104 /* This _shouldn't_ happen except by a
8105 * protocol bug causing client and server to
8106 * disagree on what is a correct signature. */
8107 c_write_str(ssh
, "Server refused public-key signature"
8108 " despite accepting key!\r\n");
8109 logevent("Server refused public-key signature"
8110 " despite accepting key!");
8111 } else if (s
->type
==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
) {
8112 /* quiet, so no c_write */
8113 logevent("Server refused keyboard-interactive authentication");
8114 } else if (s
->type
==AUTH_TYPE_GSSAPI
) {
8115 /* always quiet, so no c_write */
8116 /* also, the code down in the GSSAPI block has
8117 * already logged this in the Event Log */
8118 } else if (s
->type
== AUTH_TYPE_KEYBOARD_INTERACTIVE
) {
8119 logevent("Keyboard-interactive authentication failed");
8120 c_write_str(ssh
, "Access denied\r\n");
8122 assert(s
->type
== AUTH_TYPE_PASSWORD
);
8123 logevent("Password authentication failed");
8124 c_write_str(ssh
, "Access denied\r\n");
8126 if (conf_get_int(ssh
->conf
, CONF_change_username
)) {
8127 /* XXX perhaps we should allow
8128 * keyboard-interactive to do this too? */
8129 s
->we_are_in
= FALSE
;
8134 c_write_str(ssh
, "Further authentication required\r\n");
8135 logevent("Further authentication required");
8139 in_commasep_string("publickey", methods
, methlen
);
8141 in_commasep_string("password", methods
, methlen
);
8142 s
->can_keyb_inter
= conf_get_int(ssh
->conf
, CONF_try_ki_auth
) &&
8143 in_commasep_string("keyboard-interactive", methods
, methlen
);
8146 ssh
->gsslibs
= ssh_gss_setup(ssh
->conf
);
8147 s
->can_gssapi
= conf_get_int(ssh
->conf
, CONF_try_gssapi_auth
) &&
8148 in_commasep_string("gssapi-with-mic", methods
, methlen
) &&
8149 ssh
->gsslibs
->nlibraries
> 0;
8153 ssh
->pkt_actx
= SSH2_PKTCTX_NOAUTH
;
8155 if (s
->can_pubkey
&& !s
->done_agent
&& s
->nkeys
) {
8158 * Attempt public-key authentication using a key from Pageant.
8161 ssh
->pkt_actx
= SSH2_PKTCTX_PUBLICKEY
;
8163 logeventf(ssh
, "Trying Pageant key #%d", s
->keyi
);
8165 /* Unpack key from agent response */
8166 s
->pklen
= GET_32BIT(s
->agentp
);
8168 s
->pkblob
= (char *)s
->agentp
;
8169 s
->agentp
+= s
->pklen
;
8170 s
->alglen
= GET_32BIT(s
->pkblob
);
8171 s
->alg
= s
->pkblob
+ 4;
8172 s
->commentlen
= GET_32BIT(s
->agentp
);
8174 s
->commentp
= (char *)s
->agentp
;
8175 s
->agentp
+= s
->commentlen
;
8176 /* s->agentp now points at next key, if any */
8178 /* See if server will accept it */
8179 s
->pktout
= ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
8180 ssh2_pkt_addstring(s
->pktout
, ssh
->username
);
8181 ssh2_pkt_addstring(s
->pktout
, "ssh-connection");
8182 /* service requested */
8183 ssh2_pkt_addstring(s
->pktout
, "publickey");
8185 ssh2_pkt_addbool(s
->pktout
, FALSE
); /* no signature included */
8186 ssh2_pkt_addstring_start(s
->pktout
);
8187 ssh2_pkt_addstring_data(s
->pktout
, s
->alg
, s
->alglen
);
8188 ssh2_pkt_addstring_start(s
->pktout
);
8189 ssh2_pkt_addstring_data(s
->pktout
, s
->pkblob
, s
->pklen
);
8190 ssh2_pkt_send(ssh
, s
->pktout
);
8191 s
->type
= AUTH_TYPE_PUBLICKEY_OFFER_QUIET
;
8193 crWaitUntilV(pktin
);
8194 if (pktin
->type
!= SSH2_MSG_USERAUTH_PK_OK
) {
8196 /* Offer of key refused. */
8203 if (flags
& FLAG_VERBOSE
) {
8204 c_write_str(ssh
, "Authenticating with "
8206 c_write(ssh
, s
->commentp
, s
->commentlen
);
8207 c_write_str(ssh
, "\" from agent\r\n");
8211 * Server is willing to accept the key.
8212 * Construct a SIGN_REQUEST.
8214 s
->pktout
= ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
8215 ssh2_pkt_addstring(s
->pktout
, ssh
->username
);
8216 ssh2_pkt_addstring(s
->pktout
, "ssh-connection");
8217 /* service requested */
8218 ssh2_pkt_addstring(s
->pktout
, "publickey");
8220 ssh2_pkt_addbool(s
->pktout
, TRUE
); /* signature included */
8221 ssh2_pkt_addstring_start(s
->pktout
);
8222 ssh2_pkt_addstring_data(s
->pktout
, s
->alg
, s
->alglen
);
8223 ssh2_pkt_addstring_start(s
->pktout
);
8224 ssh2_pkt_addstring_data(s
->pktout
, s
->pkblob
, s
->pklen
);
8226 /* Ask agent for signature. */
8227 s
->siglen
= s
->pktout
->length
- 5 + 4 +
8228 ssh
->v2_session_id_len
;
8229 if (ssh
->remote_bugs
& BUG_SSH2_PK_SESSIONID
)
8231 s
->len
= 1; /* message type */
8232 s
->len
+= 4 + s
->pklen
; /* key blob */
8233 s
->len
+= 4 + s
->siglen
; /* data to sign */
8234 s
->len
+= 4; /* flags */
8235 s
->agentreq
= snewn(4 + s
->len
, char);
8236 PUT_32BIT(s
->agentreq
, s
->len
);
8237 s
->q
= s
->agentreq
+ 4;
8238 *s
->q
++ = SSH2_AGENTC_SIGN_REQUEST
;
8239 PUT_32BIT(s
->q
, s
->pklen
);
8241 memcpy(s
->q
, s
->pkblob
, s
->pklen
);
8243 PUT_32BIT(s
->q
, s
->siglen
);
8245 /* Now the data to be signed... */
8246 if (!(ssh
->remote_bugs
& BUG_SSH2_PK_SESSIONID
)) {
8247 PUT_32BIT(s
->q
, ssh
->v2_session_id_len
);
8250 memcpy(s
->q
, ssh
->v2_session_id
,
8251 ssh
->v2_session_id_len
);
8252 s
->q
+= ssh
->v2_session_id_len
;
8253 memcpy(s
->q
, s
->pktout
->data
+ 5,
8254 s
->pktout
->length
- 5);
8255 s
->q
+= s
->pktout
->length
- 5;
8256 /* And finally the (zero) flags word. */
8258 if (!agent_query(s
->agentreq
, s
->len
+ 4,
8260 ssh_agent_callback
, ssh
)) {
8264 bombout(("Unexpected data from server"
8265 " while waiting for agent"
8269 } while (pktin
|| inlen
> 0);
8270 vret
= ssh
->agent_response
;
8271 s
->retlen
= ssh
->agent_response_len
;
8276 if (s
->ret
[4] == SSH2_AGENT_SIGN_RESPONSE
) {
8277 logevent("Sending Pageant's response");
8278 ssh2_add_sigblob(ssh
, s
->pktout
,
8279 s
->pkblob
, s
->pklen
,
8281 GET_32BIT(s
->ret
+ 5));
8282 ssh2_pkt_send(ssh
, s
->pktout
);
8283 s
->type
= AUTH_TYPE_PUBLICKEY
;
8285 /* FIXME: less drastic response */
8286 bombout(("Pageant failed to answer challenge"));
8292 /* Do we have any keys left to try? */
8293 if (s
->pkblob_in_agent
) {
8294 s
->done_agent
= TRUE
;
8295 s
->tried_pubkey_config
= TRUE
;
8298 if (s
->keyi
>= s
->nkeys
)
8299 s
->done_agent
= TRUE
;
8302 } else if (s
->can_pubkey
&& s
->publickey_blob
&&
8303 !s
->tried_pubkey_config
) {
8305 struct ssh2_userkey
*key
; /* not live over crReturn */
8306 char *passphrase
; /* not live over crReturn */
8308 ssh
->pkt_actx
= SSH2_PKTCTX_PUBLICKEY
;
8310 s
->tried_pubkey_config
= TRUE
;
8313 * Try the public key supplied in the configuration.
8315 * First, offer the public blob to see if the server is
8316 * willing to accept it.
8318 s
->pktout
= ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
8319 ssh2_pkt_addstring(s
->pktout
, ssh
->username
);
8320 ssh2_pkt_addstring(s
->pktout
, "ssh-connection");
8321 /* service requested */
8322 ssh2_pkt_addstring(s
->pktout
, "publickey"); /* method */
8323 ssh2_pkt_addbool(s
->pktout
, FALSE
);
8324 /* no signature included */
8325 ssh2_pkt_addstring(s
->pktout
, s
->publickey_algorithm
);
8326 ssh2_pkt_addstring_start(s
->pktout
);
8327 ssh2_pkt_addstring_data(s
->pktout
,
8328 (char *)s
->publickey_blob
,
8329 s
->publickey_bloblen
);
8330 ssh2_pkt_send(ssh
, s
->pktout
);
8331 logevent("Offered public key");
8333 crWaitUntilV(pktin
);
8334 if (pktin
->type
!= SSH2_MSG_USERAUTH_PK_OK
) {
8335 /* Key refused. Give up. */
8336 s
->gotit
= TRUE
; /* reconsider message next loop */
8337 s
->type
= AUTH_TYPE_PUBLICKEY_OFFER_LOUD
;
8338 continue; /* process this new message */
8340 logevent("Offer of public key accepted");
8343 * Actually attempt a serious authentication using
8346 if (flags
& FLAG_VERBOSE
) {
8347 c_write_str(ssh
, "Authenticating with public key \"");
8348 c_write_str(ssh
, s
->publickey_comment
);
8349 c_write_str(ssh
, "\"\r\n");
8353 const char *error
; /* not live over crReturn */
8354 if (s
->publickey_encrypted
) {
8356 * Get a passphrase from the user.
8358 int ret
; /* need not be kept over crReturn */
8359 s
->cur_prompt
= new_prompts(ssh
->frontend
);
8360 s
->cur_prompt
->to_server
= FALSE
;
8361 s
->cur_prompt
->name
= dupstr("SSH key passphrase");
8362 add_prompt(s
->cur_prompt
,
8363 dupprintf("Passphrase for key \"%.100s\": ",
8364 s
->publickey_comment
),
8366 ret
= get_userpass_input(s
->cur_prompt
, NULL
, 0);
8369 crWaitUntilV(!pktin
);
8370 ret
= get_userpass_input(s
->cur_prompt
,
8375 /* Failed to get a passphrase. Terminate. */
8376 free_prompts(s
->cur_prompt
);
8377 ssh_disconnect(ssh
, NULL
,
8378 "Unable to authenticate",
8379 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER
,
8384 dupstr(s
->cur_prompt
->prompts
[0]->result
);
8385 free_prompts(s
->cur_prompt
);
8387 passphrase
= NULL
; /* no passphrase needed */
8391 * Try decrypting the key.
8393 s
->keyfile
= conf_get_filename(ssh
->conf
, CONF_keyfile
);
8394 key
= ssh2_load_userkey(s
->keyfile
, passphrase
, &error
);
8396 /* burn the evidence */
8397 smemclr(passphrase
, strlen(passphrase
));
8400 if (key
== SSH2_WRONG_PASSPHRASE
|| key
== NULL
) {
8402 (key
== SSH2_WRONG_PASSPHRASE
)) {
8403 c_write_str(ssh
, "Wrong passphrase\r\n");
8405 /* and loop again */
8407 c_write_str(ssh
, "Unable to load private key (");
8408 c_write_str(ssh
, error
);
8409 c_write_str(ssh
, ")\r\n");
8411 break; /* try something else */
8417 unsigned char *pkblob
, *sigblob
, *sigdata
;
8418 int pkblob_len
, sigblob_len
, sigdata_len
;
8422 * We have loaded the private key and the server
8423 * has announced that it's willing to accept it.
8424 * Hallelujah. Generate a signature and send it.
8426 s
->pktout
= ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
8427 ssh2_pkt_addstring(s
->pktout
, ssh
->username
);
8428 ssh2_pkt_addstring(s
->pktout
, "ssh-connection");
8429 /* service requested */
8430 ssh2_pkt_addstring(s
->pktout
, "publickey");
8432 ssh2_pkt_addbool(s
->pktout
, TRUE
);
8433 /* signature follows */
8434 ssh2_pkt_addstring(s
->pktout
, key
->alg
->name
);
8435 pkblob
= key
->alg
->public_blob(key
->data
,
8437 ssh2_pkt_addstring_start(s
->pktout
);
8438 ssh2_pkt_addstring_data(s
->pktout
, (char *)pkblob
,
8442 * The data to be signed is:
8446 * followed by everything so far placed in the
8449 sigdata_len
= s
->pktout
->length
- 5 + 4 +
8450 ssh
->v2_session_id_len
;
8451 if (ssh
->remote_bugs
& BUG_SSH2_PK_SESSIONID
)
8453 sigdata
= snewn(sigdata_len
, unsigned char);
8455 if (!(ssh
->remote_bugs
& BUG_SSH2_PK_SESSIONID
)) {
8456 PUT_32BIT(sigdata
+p
, ssh
->v2_session_id_len
);
8459 memcpy(sigdata
+p
, ssh
->v2_session_id
,
8460 ssh
->v2_session_id_len
);
8461 p
+= ssh
->v2_session_id_len
;
8462 memcpy(sigdata
+p
, s
->pktout
->data
+ 5,
8463 s
->pktout
->length
- 5);
8464 p
+= s
->pktout
->length
- 5;
8465 assert(p
== sigdata_len
);
8466 sigblob
= key
->alg
->sign(key
->data
, (char *)sigdata
,
8467 sigdata_len
, &sigblob_len
);
8468 ssh2_add_sigblob(ssh
, s
->pktout
, pkblob
, pkblob_len
,
8469 sigblob
, sigblob_len
);
8474 ssh2_pkt_send(ssh
, s
->pktout
);
8475 logevent("Sent public key signature");
8476 s
->type
= AUTH_TYPE_PUBLICKEY
;
8477 key
->alg
->freekey(key
->data
);
8481 } else if (s
->can_gssapi
&& !s
->tried_gssapi
) {
8483 /* GSSAPI Authentication */
8488 s
->type
= AUTH_TYPE_GSSAPI
;
8489 s
->tried_gssapi
= TRUE
;
8491 ssh
->pkt_actx
= SSH2_PKTCTX_GSSAPI
;
8494 * Pick the highest GSS library on the preference
8500 for (i
= 0; i
< ngsslibs
; i
++) {
8501 int want_id
= conf_get_int_int(ssh
->conf
,
8502 CONF_ssh_gsslist
, i
);
8503 for (j
= 0; j
< ssh
->gsslibs
->nlibraries
; j
++)
8504 if (ssh
->gsslibs
->libraries
[j
].id
== want_id
) {
8505 s
->gsslib
= &ssh
->gsslibs
->libraries
[j
];
8506 goto got_gsslib
; /* double break */
8511 * We always expect to have found something in
8512 * the above loop: we only came here if there
8513 * was at least one viable GSS library, and the
8514 * preference list should always mention
8515 * everything and only change the order.
8520 if (s
->gsslib
->gsslogmsg
)
8521 logevent(s
->gsslib
->gsslogmsg
);
8523 /* Sending USERAUTH_REQUEST with "gssapi-with-mic" method */
8524 s
->pktout
= ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
8525 ssh2_pkt_addstring(s
->pktout
, ssh
->username
);
8526 ssh2_pkt_addstring(s
->pktout
, "ssh-connection");
8527 ssh2_pkt_addstring(s
->pktout
, "gssapi-with-mic");
8528 logevent("Attempting GSSAPI authentication");
8530 /* add mechanism info */
8531 s
->gsslib
->indicate_mech(s
->gsslib
, &s
->gss_buf
);
8533 /* number of GSSAPI mechanisms */
8534 ssh2_pkt_adduint32(s
->pktout
,1);
8536 /* length of OID + 2 */
8537 ssh2_pkt_adduint32(s
->pktout
, s
->gss_buf
.length
+ 2);
8538 ssh2_pkt_addbyte(s
->pktout
, SSH2_GSS_OIDTYPE
);
8541 ssh2_pkt_addbyte(s
->pktout
, (unsigned char) s
->gss_buf
.length
);
8543 ssh_pkt_adddata(s
->pktout
, s
->gss_buf
.value
,
8545 ssh2_pkt_send(ssh
, s
->pktout
);
8546 crWaitUntilV(pktin
);
8547 if (pktin
->type
!= SSH2_MSG_USERAUTH_GSSAPI_RESPONSE
) {
8548 logevent("GSSAPI authentication request refused");
8552 /* check returned packet ... */
8554 ssh_pkt_getstring(pktin
, &data
, &len
);
8555 s
->gss_rcvtok
.value
= data
;
8556 s
->gss_rcvtok
.length
= len
;
8557 if (s
->gss_rcvtok
.length
!= s
->gss_buf
.length
+ 2 ||
8558 ((char *)s
->gss_rcvtok
.value
)[0] != SSH2_GSS_OIDTYPE
||
8559 ((char *)s
->gss_rcvtok
.value
)[1] != s
->gss_buf
.length
||
8560 memcmp((char *)s
->gss_rcvtok
.value
+ 2,
8561 s
->gss_buf
.value
,s
->gss_buf
.length
) ) {
8562 logevent("GSSAPI authentication - wrong response from server");
8566 /* now start running */
8567 s
->gss_stat
= s
->gsslib
->import_name(s
->gsslib
,
8570 if (s
->gss_stat
!= SSH_GSS_OK
) {
8571 if (s
->gss_stat
== SSH_GSS_BAD_HOST_NAME
)
8572 logevent("GSSAPI import name failed - Bad service name");
8574 logevent("GSSAPI import name failed");
8578 /* fetch TGT into GSS engine */
8579 s
->gss_stat
= s
->gsslib
->acquire_cred(s
->gsslib
, &s
->gss_ctx
);
8581 if (s
->gss_stat
!= SSH_GSS_OK
) {
8582 logevent("GSSAPI authentication failed to get credentials");
8583 s
->gsslib
->release_name(s
->gsslib
, &s
->gss_srv_name
);
8587 /* initial tokens are empty */
8588 SSH_GSS_CLEAR_BUF(&s
->gss_rcvtok
);
8589 SSH_GSS_CLEAR_BUF(&s
->gss_sndtok
);
8591 /* now enter the loop */
8593 s
->gss_stat
= s
->gsslib
->init_sec_context
8597 conf_get_int(ssh
->conf
, CONF_gssapifwd
),
8601 if (s
->gss_stat
!=SSH_GSS_S_COMPLETE
&&
8602 s
->gss_stat
!=SSH_GSS_S_CONTINUE_NEEDED
) {
8603 logevent("GSSAPI authentication initialisation failed");
8605 if (s
->gsslib
->display_status(s
->gsslib
, s
->gss_ctx
,
8606 &s
->gss_buf
) == SSH_GSS_OK
) {
8607 logevent(s
->gss_buf
.value
);
8608 sfree(s
->gss_buf
.value
);
8613 logevent("GSSAPI authentication initialised");
8615 /* Client and server now exchange tokens until GSSAPI
8616 * no longer says CONTINUE_NEEDED */
8618 if (s
->gss_sndtok
.length
!= 0) {
8619 s
->pktout
= ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_TOKEN
);
8620 ssh_pkt_addstring_start(s
->pktout
);
8621 ssh_pkt_addstring_data(s
->pktout
,s
->gss_sndtok
.value
,s
->gss_sndtok
.length
);
8622 ssh2_pkt_send(ssh
, s
->pktout
);
8623 s
->gsslib
->free_tok(s
->gsslib
, &s
->gss_sndtok
);
8626 if (s
->gss_stat
== SSH_GSS_S_CONTINUE_NEEDED
) {
8627 crWaitUntilV(pktin
);
8628 if (pktin
->type
!= SSH2_MSG_USERAUTH_GSSAPI_TOKEN
) {
8629 logevent("GSSAPI authentication - bad server response");
8630 s
->gss_stat
= SSH_GSS_FAILURE
;
8633 ssh_pkt_getstring(pktin
, &data
, &len
);
8634 s
->gss_rcvtok
.value
= data
;
8635 s
->gss_rcvtok
.length
= len
;
8637 } while (s
-> gss_stat
== SSH_GSS_S_CONTINUE_NEEDED
);
8639 if (s
->gss_stat
!= SSH_GSS_OK
) {
8640 s
->gsslib
->release_name(s
->gsslib
, &s
->gss_srv_name
);
8641 s
->gsslib
->release_cred(s
->gsslib
, &s
->gss_ctx
);
8644 logevent("GSSAPI authentication loop finished OK");
8646 /* Now send the MIC */
8648 s
->pktout
= ssh2_pkt_init(0);
8649 micoffset
= s
->pktout
->length
;
8650 ssh_pkt_addstring_start(s
->pktout
);
8651 ssh_pkt_addstring_data(s
->pktout
, (char *)ssh
->v2_session_id
, ssh
->v2_session_id_len
);
8652 ssh_pkt_addbyte(s
->pktout
, SSH2_MSG_USERAUTH_REQUEST
);
8653 ssh_pkt_addstring(s
->pktout
, ssh
->username
);
8654 ssh_pkt_addstring(s
->pktout
, "ssh-connection");
8655 ssh_pkt_addstring(s
->pktout
, "gssapi-with-mic");
8657 s
->gss_buf
.value
= (char *)s
->pktout
->data
+ micoffset
;
8658 s
->gss_buf
.length
= s
->pktout
->length
- micoffset
;
8660 s
->gsslib
->get_mic(s
->gsslib
, s
->gss_ctx
, &s
->gss_buf
, &mic
);
8661 s
->pktout
= ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_MIC
);
8662 ssh_pkt_addstring_start(s
->pktout
);
8663 ssh_pkt_addstring_data(s
->pktout
, mic
.value
, mic
.length
);
8664 ssh2_pkt_send(ssh
, s
->pktout
);
8665 s
->gsslib
->free_mic(s
->gsslib
, &mic
);
8669 s
->gsslib
->release_name(s
->gsslib
, &s
->gss_srv_name
);
8670 s
->gsslib
->release_cred(s
->gsslib
, &s
->gss_ctx
);
8673 } else if (s
->can_keyb_inter
&& !s
->kbd_inter_refused
) {
8676 * Keyboard-interactive authentication.
8679 s
->type
= AUTH_TYPE_KEYBOARD_INTERACTIVE
;
8681 ssh
->pkt_actx
= SSH2_PKTCTX_KBDINTER
;
8683 s
->pktout
= ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
8684 ssh2_pkt_addstring(s
->pktout
, ssh
->username
);
8685 ssh2_pkt_addstring(s
->pktout
, "ssh-connection");
8686 /* service requested */
8687 ssh2_pkt_addstring(s
->pktout
, "keyboard-interactive");
8689 ssh2_pkt_addstring(s
->pktout
, ""); /* lang */
8690 ssh2_pkt_addstring(s
->pktout
, ""); /* submethods */
8691 ssh2_pkt_send(ssh
, s
->pktout
);
8693 logevent("Attempting keyboard-interactive authentication");
8695 crWaitUntilV(pktin
);
8696 if (pktin
->type
!= SSH2_MSG_USERAUTH_INFO_REQUEST
) {
8697 /* Server is not willing to do keyboard-interactive
8698 * at all (or, bizarrely but legally, accepts the
8699 * user without actually issuing any prompts).
8700 * Give up on it entirely. */
8702 s
->type
= AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
;
8703 s
->kbd_inter_refused
= TRUE
; /* don't try it again */
8708 * Loop while the server continues to send INFO_REQUESTs.
8710 while (pktin
->type
== SSH2_MSG_USERAUTH_INFO_REQUEST
) {
8712 char *name
, *inst
, *lang
;
8713 int name_len
, inst_len
, lang_len
;
8717 * We've got a fresh USERAUTH_INFO_REQUEST.
8718 * Get the preamble and start building a prompt.
8720 ssh_pkt_getstring(pktin
, &name
, &name_len
);
8721 ssh_pkt_getstring(pktin
, &inst
, &inst_len
);
8722 ssh_pkt_getstring(pktin
, &lang
, &lang_len
);
8723 s
->cur_prompt
= new_prompts(ssh
->frontend
);
8724 s
->cur_prompt
->to_server
= TRUE
;
8727 * Get any prompt(s) from the packet.
8729 s
->num_prompts
= ssh_pkt_getuint32(pktin
);
8730 for (i
= 0; i
< s
->num_prompts
; i
++) {
8734 static char noprompt
[] =
8735 "<server failed to send prompt>: ";
8737 ssh_pkt_getstring(pktin
, &prompt
, &prompt_len
);
8738 echo
= ssh2_pkt_getbool(pktin
);
8741 prompt_len
= lenof(noprompt
)-1;
8743 add_prompt(s
->cur_prompt
,
8744 dupprintf("%.*s", prompt_len
, prompt
),
8749 /* FIXME: better prefix to distinguish from
8751 s
->cur_prompt
->name
=
8752 dupprintf("SSH server: %.*s", name_len
, name
);
8753 s
->cur_prompt
->name_reqd
= TRUE
;
8755 s
->cur_prompt
->name
=
8756 dupstr("SSH server authentication");
8757 s
->cur_prompt
->name_reqd
= FALSE
;
8759 /* We add a prefix to try to make it clear that a prompt
8760 * has come from the server.
8761 * FIXME: ugly to print "Using..." in prompt _every_
8762 * time round. Can this be done more subtly? */
8763 /* Special case: for reasons best known to themselves,
8764 * some servers send k-i requests with no prompts and
8765 * nothing to display. Keep quiet in this case. */
8766 if (s
->num_prompts
|| name_len
|| inst_len
) {
8767 s
->cur_prompt
->instruction
=
8768 dupprintf("Using keyboard-interactive authentication.%s%.*s",
8769 inst_len ?
"\n" : "", inst_len
, inst
);
8770 s
->cur_prompt
->instr_reqd
= TRUE
;
8772 s
->cur_prompt
->instr_reqd
= FALSE
;
8776 * Display any instructions, and get the user's
8780 int ret
; /* not live over crReturn */
8781 ret
= get_userpass_input(s
->cur_prompt
, NULL
, 0);
8784 crWaitUntilV(!pktin
);
8785 ret
= get_userpass_input(s
->cur_prompt
, in
, inlen
);
8790 * Failed to get responses. Terminate.
8792 free_prompts(s
->cur_prompt
);
8793 ssh_disconnect(ssh
, NULL
, "Unable to authenticate",
8794 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER
,
8801 * Send the response(s) to the server.
8803 s
->pktout
= ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE
);
8804 ssh2_pkt_adduint32(s
->pktout
, s
->num_prompts
);
8805 for (i
=0; i
< s
->num_prompts
; i
++) {
8806 dont_log_password(ssh
, s
->pktout
, PKTLOG_BLANK
);
8807 ssh2_pkt_addstring(s
->pktout
,
8808 s
->cur_prompt
->prompts
[i
]->result
);
8809 end_log_omission(ssh
, s
->pktout
);
8811 ssh2_pkt_send_with_padding(ssh
, s
->pktout
, 256);
8814 * Free the prompts structure from this iteration.
8815 * If there's another, a new one will be allocated
8816 * when we return to the top of this while loop.
8818 free_prompts(s
->cur_prompt
);
8821 * Get the next packet in case it's another
8824 crWaitUntilV(pktin
);
8829 * We should have SUCCESS or FAILURE now.
8833 } else if (s
->can_passwd
) {
8836 * Plain old password authentication.
8838 int ret
; /* not live over crReturn */
8839 int changereq_first_time
; /* not live over crReturn */
8841 ssh
->pkt_actx
= SSH2_PKTCTX_PASSWORD
;
8843 s
->cur_prompt
= new_prompts(ssh
->frontend
);
8844 s
->cur_prompt
->to_server
= TRUE
;
8845 s
->cur_prompt
->name
= dupstr("SSH password");
8846 add_prompt(s
->cur_prompt
, dupprintf("%s@%s's password: ",
8851 ret
= get_userpass_input(s
->cur_prompt
, NULL
, 0);
8854 crWaitUntilV(!pktin
);
8855 ret
= get_userpass_input(s
->cur_prompt
, in
, inlen
);
8860 * Failed to get responses. Terminate.
8862 free_prompts(s
->cur_prompt
);
8863 ssh_disconnect(ssh
, NULL
, "Unable to authenticate",
8864 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER
,
8869 * Squirrel away the password. (We may need it later if
8870 * asked to change it.)
8872 s
->password
= dupstr(s
->cur_prompt
->prompts
[0]->result
);
8873 free_prompts(s
->cur_prompt
);
8876 * Send the password packet.
8878 * We pad out the password packet to 256 bytes to make
8879 * it harder for an attacker to find the length of the
8882 * Anyone using a password longer than 256 bytes
8883 * probably doesn't have much to worry about from
8884 * people who find out how long their password is!
8886 s
->pktout
= ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
8887 ssh2_pkt_addstring(s
->pktout
, ssh
->username
);
8888 ssh2_pkt_addstring(s
->pktout
, "ssh-connection");
8889 /* service requested */
8890 ssh2_pkt_addstring(s
->pktout
, "password");
8891 ssh2_pkt_addbool(s
->pktout
, FALSE
);
8892 dont_log_password(ssh
, s
->pktout
, PKTLOG_BLANK
);
8893 ssh2_pkt_addstring(s
->pktout
, s
->password
);
8894 end_log_omission(ssh
, s
->pktout
);
8895 ssh2_pkt_send_with_padding(ssh
, s
->pktout
, 256);
8896 logevent("Sent password");
8897 s
->type
= AUTH_TYPE_PASSWORD
;
8900 * Wait for next packet, in case it's a password change
8903 crWaitUntilV(pktin
);
8904 changereq_first_time
= TRUE
;
8906 while (pktin
->type
== SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ
) {
8909 * We're being asked for a new password
8910 * (perhaps not for the first time).
8911 * Loop until the server accepts it.
8914 int got_new
= FALSE
; /* not live over crReturn */
8915 char *prompt
; /* not live over crReturn */
8916 int prompt_len
; /* not live over crReturn */
8920 if (changereq_first_time
)
8921 msg
= "Server requested password change";
8923 msg
= "Server rejected new password";
8925 c_write_str(ssh
, msg
);
8926 c_write_str(ssh
, "\r\n");
8929 ssh_pkt_getstring(pktin
, &prompt
, &prompt_len
);
8931 s
->cur_prompt
= new_prompts(ssh
->frontend
);
8932 s
->cur_prompt
->to_server
= TRUE
;
8933 s
->cur_prompt
->name
= dupstr("New SSH password");
8934 s
->cur_prompt
->instruction
=
8935 dupprintf("%.*s", prompt_len
, prompt
);
8936 s
->cur_prompt
->instr_reqd
= TRUE
;
8938 * There's no explicit requirement in the protocol
8939 * for the "old" passwords in the original and
8940 * password-change messages to be the same, and
8941 * apparently some Cisco kit supports password change
8942 * by the user entering a blank password originally
8943 * and the real password subsequently, so,
8944 * reluctantly, we prompt for the old password again.
8946 * (On the other hand, some servers don't even bother
8947 * to check this field.)
8949 add_prompt(s
->cur_prompt
,
8950 dupstr("Current password (blank for previously entered password): "),
8952 add_prompt(s
->cur_prompt
, dupstr("Enter new password: "),
8954 add_prompt(s
->cur_prompt
, dupstr("Confirm new password: "),
8958 * Loop until the user manages to enter the same
8963 ret
= get_userpass_input(s
->cur_prompt
, NULL
, 0);
8966 crWaitUntilV(!pktin
);
8967 ret
= get_userpass_input(s
->cur_prompt
, in
, inlen
);
8972 * Failed to get responses. Terminate.
8974 /* burn the evidence */
8975 free_prompts(s
->cur_prompt
);
8976 smemclr(s
->password
, strlen(s
->password
));
8978 ssh_disconnect(ssh
, NULL
, "Unable to authenticate",
8979 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER
,
8985 * If the user specified a new original password
8986 * (IYSWIM), overwrite any previously specified
8988 * (A side effect is that the user doesn't have to
8989 * re-enter it if they louse up the new password.)
8991 if (s
->cur_prompt
->prompts
[0]->result
[0]) {
8992 smemclr(s
->password
, strlen(s
->password
));
8993 /* burn the evidence */
8996 dupstr(s
->cur_prompt
->prompts
[0]->result
);
9000 * Check the two new passwords match.
9002 got_new
= (strcmp(s
->cur_prompt
->prompts
[1]->result
,
9003 s
->cur_prompt
->prompts
[2]->result
)
9006 /* They don't. Silly user. */
9007 c_write_str(ssh
, "Passwords do not match\r\n");
9012 * Send the new password (along with the old one).
9013 * (see above for padding rationale)
9015 s
->pktout
= ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
9016 ssh2_pkt_addstring(s
->pktout
, ssh
->username
);
9017 ssh2_pkt_addstring(s
->pktout
, "ssh-connection");
9018 /* service requested */
9019 ssh2_pkt_addstring(s
->pktout
, "password");
9020 ssh2_pkt_addbool(s
->pktout
, TRUE
);
9021 dont_log_password(ssh
, s
->pktout
, PKTLOG_BLANK
);
9022 ssh2_pkt_addstring(s
->pktout
, s
->password
);
9023 ssh2_pkt_addstring(s
->pktout
,
9024 s
->cur_prompt
->prompts
[1]->result
);
9025 free_prompts(s
->cur_prompt
);
9026 end_log_omission(ssh
, s
->pktout
);
9027 ssh2_pkt_send_with_padding(ssh
, s
->pktout
, 256);
9028 logevent("Sent new password");
9031 * Now see what the server has to say about it.
9032 * (If it's CHANGEREQ again, it's not happy with the
9035 crWaitUntilV(pktin
);
9036 changereq_first_time
= FALSE
;
9041 * We need to reexamine the current pktin at the top
9042 * of the loop. Either:
9043 * - we weren't asked to change password at all, in
9044 * which case it's a SUCCESS or FAILURE with the
9046 * - we sent a new password, and the server was
9047 * either OK with it (SUCCESS or FAILURE w/partial
9048 * success) or unhappy with the _old_ password
9049 * (FAILURE w/o partial success)
9050 * In any of these cases, we go back to the top of
9051 * the loop and start again.
9056 * We don't need the old password any more, in any
9057 * case. Burn the evidence.
9059 smemclr(s
->password
, strlen(s
->password
));
9063 char *str
= dupprintf("No supported authentication methods available"
9064 " (server sent: %.*s)",
9067 ssh_disconnect(ssh
, str
,
9068 "No supported authentication methods available",
9069 SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE
,
9079 ssh
->packet_dispatch
[SSH2_MSG_USERAUTH_BANNER
] = NULL
;
9081 /* Clear up various bits and pieces from authentication. */
9082 if (s
->publickey_blob
) {
9083 sfree(s
->publickey_blob
);
9084 sfree(s
->publickey_comment
);
9086 if (s
->agent_response
)
9087 sfree(s
->agent_response
);
9089 if (s
->userauth_success
) {
9091 * We've just received USERAUTH_SUCCESS, and we haven't sent any
9092 * packets since. Signal the transport layer to consider enacting
9093 * delayed compression.
9095 * (Relying on we_are_in is not sufficient, as
9096 * draft-miller-secsh-compression-delayed is quite clear that it
9097 * triggers on USERAUTH_SUCCESS specifically, and we_are_in can
9098 * become set for other reasons.)
9100 do_ssh2_transport(ssh
, "enabling delayed compression", -2, NULL
);
9104 * Now the connection protocol has started, one way or another.
9107 ssh
->channels
= newtree234(ssh_channelcmp
);
9110 * Set up handlers for some connection protocol messages, so we
9111 * don't have to handle them repeatedly in this coroutine.
9113 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_WINDOW_ADJUST
] =
9114 ssh2_msg_channel_window_adjust
;
9115 ssh
->packet_dispatch
[SSH2_MSG_GLOBAL_REQUEST
] =
9116 ssh2_msg_global_request
;
9119 * Create the main session channel.
9121 if (conf_get_int(ssh
->conf
, CONF_ssh_no_shell
)) {
9122 ssh
->mainchan
= NULL
;
9123 } else if (*conf_get_str(ssh
->conf
, CONF_ssh_nc_host
)) {
9125 * Just start a direct-tcpip channel and use it as the main
9128 ssh
->mainchan
= snew(struct ssh_channel
);
9129 ssh
->mainchan
->ssh
= ssh
;
9130 ssh2_channel_init(ssh
->mainchan
);
9132 "Opening direct-tcpip channel to %s:%d in place of session",
9133 conf_get_str(ssh
->conf
, CONF_ssh_nc_host
),
9134 conf_get_int(ssh
->conf
, CONF_ssh_nc_port
));
9135 s
->pktout
= ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN
);
9136 ssh2_pkt_addstring(s
->pktout
, "direct-tcpip");
9137 ssh2_pkt_adduint32(s
->pktout
, ssh
->mainchan
->localid
);
9138 ssh2_pkt_adduint32(s
->pktout
, ssh
->mainchan
->v
.v2
.locwindow
);/* our window size */
9139 ssh2_pkt_adduint32(s
->pktout
, OUR_V2_MAXPKT
); /* our max pkt size */
9140 ssh2_pkt_addstring(s
->pktout
, conf_get_str(ssh
->conf
, CONF_ssh_nc_host
));
9141 ssh2_pkt_adduint32(s
->pktout
, conf_get_int(ssh
->conf
, CONF_ssh_nc_port
));
9143 * There's nothing meaningful to put in the originator
9144 * fields, but some servers insist on syntactically correct
9147 ssh2_pkt_addstring(s
->pktout
, "0.0.0.0");
9148 ssh2_pkt_adduint32(s
->pktout
, 0);
9149 ssh2_pkt_send(ssh
, s
->pktout
);
9151 crWaitUntilV(pktin
);
9152 if (pktin
->type
!= SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
) {
9153 bombout(("Server refused to open a direct-tcpip channel"));
9155 /* FIXME: error data comes back in FAILURE packet */
9157 if (ssh_pkt_getuint32(pktin
) != ssh
->mainchan
->localid
) {
9158 bombout(("Server's channel confirmation cited wrong channel"));
9161 ssh
->mainchan
->remoteid
= ssh_pkt_getuint32(pktin
);
9162 ssh
->mainchan
->halfopen
= FALSE
;
9163 ssh
->mainchan
->type
= CHAN_MAINSESSION
;
9164 ssh
->mainchan
->v
.v2
.remwindow
= ssh_pkt_getuint32(pktin
);
9165 ssh
->mainchan
->v
.v2
.remmaxpkt
= ssh_pkt_getuint32(pktin
);
9166 add234(ssh
->channels
, ssh
->mainchan
);
9167 update_specials_menu(ssh
->frontend
);
9168 logevent("Opened direct-tcpip channel");
9171 ssh
->mainchan
= snew(struct ssh_channel
);
9172 ssh
->mainchan
->ssh
= ssh
;
9173 ssh2_channel_init(ssh
->mainchan
);
9174 s
->pktout
= ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN
);
9175 ssh2_pkt_addstring(s
->pktout
, "session");
9176 ssh2_pkt_adduint32(s
->pktout
, ssh
->mainchan
->localid
);
9177 ssh2_pkt_adduint32(s
->pktout
, ssh
->mainchan
->v
.v2
.locwindow
);/* our window size */
9178 ssh2_pkt_adduint32(s
->pktout
, OUR_V2_MAXPKT
); /* our max pkt size */
9179 ssh2_pkt_send(ssh
, s
->pktout
);
9180 crWaitUntilV(pktin
);
9181 if (pktin
->type
!= SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
) {
9182 bombout(("Server refused to open a session"));
9184 /* FIXME: error data comes back in FAILURE packet */
9186 if (ssh_pkt_getuint32(pktin
) != ssh
->mainchan
->localid
) {
9187 bombout(("Server's channel confirmation cited wrong channel"));
9190 ssh
->mainchan
->remoteid
= ssh_pkt_getuint32(pktin
);
9191 ssh
->mainchan
->halfopen
= FALSE
;
9192 ssh
->mainchan
->type
= CHAN_MAINSESSION
;
9193 ssh
->mainchan
->v
.v2
.remwindow
= ssh_pkt_getuint32(pktin
);
9194 ssh
->mainchan
->v
.v2
.remmaxpkt
= ssh_pkt_getuint32(pktin
);
9195 add234(ssh
->channels
, ssh
->mainchan
);
9196 update_specials_menu(ssh
->frontend
);
9197 logevent("Opened channel for session");
9198 ssh
->ncmode
= FALSE
;
9202 * Now we have a channel, make dispatch table entries for
9203 * general channel-based messages.
9205 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_DATA
] =
9206 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_EXTENDED_DATA
] =
9207 ssh2_msg_channel_data
;
9208 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_EOF
] = ssh2_msg_channel_eof
;
9209 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_CLOSE
] = ssh2_msg_channel_close
;
9210 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
] =
9211 ssh2_msg_channel_open_confirmation
;
9212 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_OPEN_FAILURE
] =
9213 ssh2_msg_channel_open_failure
;
9214 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_REQUEST
] =
9215 ssh2_msg_channel_request
;
9216 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_OPEN
] =
9217 ssh2_msg_channel_open
;
9218 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_SUCCESS
] = ssh2_msg_channel_response
;
9219 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_FAILURE
] = ssh2_msg_channel_response
;
9222 if (ssh
->mainchan
&& conf_get_int(ssh
->conf
, CONF_ssh_simple
)) {
9224 * This message indicates to the server that we promise
9225 * not to try to run any other channel in parallel with
9226 * this one, so it's safe for it to advertise a very large
9227 * window and leave the flow control to TCP.
9229 s
->pktout
= ssh2_chanreq_init(ssh
->mainchan
,
9230 "simple@putty.projects.tartarus.org",
9232 ssh2_pkt_send(ssh
, s
->pktout
);
9236 * Enable port forwardings.
9238 ssh_setup_portfwd(ssh
, ssh
->conf
);
9241 * Send the CHANNEL_REQUESTS for the main channel. Each one is
9242 * handled by its own little asynchronous co-routine.
9246 * Potentially enable X11 forwarding.
9248 ssh2_maybe_setup_x11(ssh
->mainchan
, NULL
, NULL
);
9251 * Potentially enable agent forwarding.
9253 ssh2_maybe_setup_agent(ssh
->mainchan
, NULL
, NULL
);
9256 * Now allocate a pty for the session.
9258 ssh2_maybe_setup_pty(ssh
->mainchan
, NULL
, NULL
);
9261 * Send environment variables.
9263 ssh2_setup_env(ssh
->mainchan
, NULL
, NULL
);
9266 * Start a shell or a remote command. We may have to attempt
9267 * this twice if the config data has provided a second choice
9270 if (ssh
->mainchan
&& !ssh
->ncmode
) while (1) {
9274 if (ssh
->fallback_cmd
) {
9275 subsys
= conf_get_int(ssh
->conf
, CONF_ssh_subsys2
);
9276 cmd
= conf_get_str(ssh
->conf
, CONF_remote_cmd2
);
9278 subsys
= conf_get_int(ssh
->conf
, CONF_ssh_subsys
);
9279 cmd
= conf_get_str(ssh
->conf
, CONF_remote_cmd
);
9283 s
->pktout
= ssh2_chanreq_init(ssh
->mainchan
, "subsystem",
9284 ssh2_response_authconn
, NULL
);
9285 ssh2_pkt_addstring(s
->pktout
, cmd
);
9287 s
->pktout
= ssh2_chanreq_init(ssh
->mainchan
, "exec",
9288 ssh2_response_authconn
, NULL
);
9289 ssh2_pkt_addstring(s
->pktout
, cmd
);
9291 s
->pktout
= ssh2_chanreq_init(ssh
->mainchan
, "shell",
9292 ssh2_response_authconn
, NULL
);
9294 ssh2_pkt_send(ssh
, s
->pktout
);
9296 crWaitUntilV(pktin
);
9298 if (pktin
->type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
9299 if (pktin
->type
!= SSH2_MSG_CHANNEL_FAILURE
) {
9300 bombout(("Unexpected response to shell/command request:"
9301 " packet type %d", pktin
->type
));
9305 * We failed to start the command. If this is the
9306 * fallback command, we really are finished; if it's
9307 * not, and if the fallback command exists, try falling
9308 * back to it before complaining.
9310 if (!ssh
->fallback_cmd
&&
9311 *conf_get_str(ssh
->conf
, CONF_remote_cmd2
)) {
9312 logevent("Primary command failed; attempting fallback");
9313 ssh
->fallback_cmd
= TRUE
;
9316 bombout(("Server refused to start a shell/command"));
9319 logevent("Started a shell/command");
9324 ssh
->state
= SSH_STATE_SESSION
;
9325 if (ssh
->size_needed
)
9326 ssh_size(ssh
, ssh
->term_width
, ssh
->term_height
);
9327 if (ssh
->eof_needed
)
9328 ssh_special(ssh
, TS_EOF
);
9331 * All the initial channel requests are done, so install the default
9334 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_SUCCESS
] = ssh2_msg_channel_response
;
9335 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_FAILURE
] = ssh2_msg_channel_response
;
9341 ldisc_send(ssh
->ldisc
, NULL
, 0, 0);/* cause ldisc to notice changes */
9346 s
->try_send
= FALSE
;
9350 * _All_ the connection-layer packets we expect to
9351 * receive are now handled by the dispatch table.
9352 * Anything that reaches here must be bogus.
9355 bombout(("Strange packet received: type %d", pktin
->type
));
9357 } else if (ssh
->mainchan
) {
9359 * We have spare data. Add it to the channel buffer.
9361 ssh2_add_channel_data(ssh
->mainchan
, (char *)in
, inlen
);
9366 struct ssh_channel
*c
;
9368 * Try to send data on all channels if we can.
9370 for (i
= 0; NULL
!= (c
= index234(ssh
->channels
, i
)); i
++)
9371 ssh2_try_send_and_unthrottle(ssh
, c
);
9379 * Handlers for SSH-2 messages that might arrive at any moment.
9381 static void ssh2_msg_disconnect(Ssh ssh
, struct Packet
*pktin
)
9383 /* log reason code in disconnect message */
9387 reason
= ssh_pkt_getuint32(pktin
);
9388 ssh_pkt_getstring(pktin
, &msg
, &msglen
);
9390 if (reason
> 0 && reason
< lenof(ssh2_disconnect_reasons
)) {
9391 buf
= dupprintf("Received disconnect message (%s)",
9392 ssh2_disconnect_reasons
[reason
]);
9394 buf
= dupprintf("Received disconnect message (unknown"
9395 " type %d)", reason
);
9399 buf
= dupprintf("Disconnection message text: %.*s",
9402 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%.*s\"",
9404 (reason
> 0 && reason
< lenof(ssh2_disconnect_reasons
)) ?
9405 ssh2_disconnect_reasons
[reason
] : "unknown",
9410 static void ssh2_msg_debug(Ssh ssh
, struct Packet
*pktin
)
9412 /* log the debug message */
9416 /* XXX maybe we should actually take notice of the return value */
9417 ssh2_pkt_getbool(pktin
);
9418 ssh_pkt_getstring(pktin
, &msg
, &msglen
);
9420 logeventf(ssh
, "Remote debug message: %.*s", msglen
, msg
);
9423 static void ssh2_msg_transport(Ssh ssh
, struct Packet
*pktin
)
9425 do_ssh2_transport(ssh
, NULL
, 0, pktin
);
9429 * Called if we receive a packet that isn't allowed by the protocol.
9430 * This only applies to packets whose meaning PuTTY understands.
9431 * Entirely unknown packets are handled below.
9433 static void ssh2_msg_unexpected(Ssh ssh
, struct Packet
*pktin
)
9435 char *buf
= dupprintf("Server protocol violation: unexpected %s packet",
9436 ssh2_pkt_type(ssh
->pkt_kctx
, ssh
->pkt_actx
,
9438 ssh_disconnect(ssh
, NULL
, buf
, SSH2_DISCONNECT_PROTOCOL_ERROR
, FALSE
);
9442 static void ssh2_msg_something_unimplemented(Ssh ssh
, struct Packet
*pktin
)
9444 struct Packet
*pktout
;
9445 pktout
= ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED
);
9446 ssh2_pkt_adduint32(pktout
, pktin
->sequence
);
9448 * UNIMPLEMENTED messages MUST appear in the same order as the
9449 * messages they respond to. Hence, never queue them.
9451 ssh2_pkt_send_noqueue(ssh
, pktout
);
9455 * Handle the top-level SSH-2 protocol.
9457 static void ssh2_protocol_setup(Ssh ssh
)
9462 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
9464 for (i
= 0; i
< 256; i
++)
9465 ssh
->packet_dispatch
[i
] = ssh2_msg_something_unimplemented
;
9468 * Initially, we only accept transport messages (and a few generic
9469 * ones). do_ssh2_authconn will add more when it starts.
9470 * Messages that are understood but not currently acceptable go to
9471 * ssh2_msg_unexpected.
9473 ssh
->packet_dispatch
[SSH2_MSG_UNIMPLEMENTED
] = ssh2_msg_unexpected
;
9474 ssh
->packet_dispatch
[SSH2_MSG_SERVICE_REQUEST
] = ssh2_msg_unexpected
;
9475 ssh
->packet_dispatch
[SSH2_MSG_SERVICE_ACCEPT
] = ssh2_msg_unexpected
;
9476 ssh
->packet_dispatch
[SSH2_MSG_KEXINIT
] = ssh2_msg_transport
;
9477 ssh
->packet_dispatch
[SSH2_MSG_NEWKEYS
] = ssh2_msg_transport
;
9478 ssh
->packet_dispatch
[SSH2_MSG_KEXDH_INIT
] = ssh2_msg_transport
;
9479 ssh
->packet_dispatch
[SSH2_MSG_KEXDH_REPLY
] = ssh2_msg_transport
;
9480 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = ssh2_msg_transport; duplicate case value */
9481 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = ssh2_msg_transport; duplicate case value */
9482 ssh
->packet_dispatch
[SSH2_MSG_KEX_DH_GEX_INIT
] = ssh2_msg_transport
;
9483 ssh
->packet_dispatch
[SSH2_MSG_KEX_DH_GEX_REPLY
] = ssh2_msg_transport
;
9484 ssh
->packet_dispatch
[SSH2_MSG_USERAUTH_REQUEST
] = ssh2_msg_unexpected
;
9485 ssh
->packet_dispatch
[SSH2_MSG_USERAUTH_FAILURE
] = ssh2_msg_unexpected
;
9486 ssh
->packet_dispatch
[SSH2_MSG_USERAUTH_SUCCESS
] = ssh2_msg_unexpected
;
9487 ssh
->packet_dispatch
[SSH2_MSG_USERAUTH_BANNER
] = ssh2_msg_unexpected
;
9488 ssh
->packet_dispatch
[SSH2_MSG_USERAUTH_PK_OK
] = ssh2_msg_unexpected
;
9489 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = ssh2_msg_unexpected; duplicate case value */
9490 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = ssh2_msg_unexpected; duplicate case value */
9491 ssh
->packet_dispatch
[SSH2_MSG_USERAUTH_INFO_RESPONSE
] = ssh2_msg_unexpected
;
9492 ssh
->packet_dispatch
[SSH2_MSG_GLOBAL_REQUEST
] = ssh2_msg_unexpected
;
9493 ssh
->packet_dispatch
[SSH2_MSG_REQUEST_SUCCESS
] = ssh2_msg_unexpected
;
9494 ssh
->packet_dispatch
[SSH2_MSG_REQUEST_FAILURE
] = ssh2_msg_unexpected
;
9495 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_OPEN
] = ssh2_msg_unexpected
;
9496 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
] = ssh2_msg_unexpected
;
9497 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_OPEN_FAILURE
] = ssh2_msg_unexpected
;
9498 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_WINDOW_ADJUST
] = ssh2_msg_unexpected
;
9499 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_DATA
] = ssh2_msg_unexpected
;
9500 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_EXTENDED_DATA
] = ssh2_msg_unexpected
;
9501 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_EOF
] = ssh2_msg_unexpected
;
9502 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_CLOSE
] = ssh2_msg_unexpected
;
9503 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_REQUEST
] = ssh2_msg_unexpected
;
9504 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_SUCCESS
] = ssh2_msg_unexpected
;
9505 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_FAILURE
] = ssh2_msg_unexpected
;
9508 * These messages have a special handler from the start.
9510 ssh
->packet_dispatch
[SSH2_MSG_DISCONNECT
] = ssh2_msg_disconnect
;
9511 ssh
->packet_dispatch
[SSH2_MSG_IGNORE
] = ssh_msg_ignore
; /* shared with SSH-1 */
9512 ssh
->packet_dispatch
[SSH2_MSG_DEBUG
] = ssh2_msg_debug
;
9515 static void ssh2_timer(void *ctx
, long now
)
9519 if (ssh
->state
== SSH_STATE_CLOSED
)
9522 if (!ssh
->kex_in_progress
&& conf_get_int(ssh
->conf
, CONF_ssh_rekey_time
) != 0 &&
9523 now
- ssh
->next_rekey
>= 0) {
9524 do_ssh2_transport(ssh
, "timeout", -1, NULL
);
9528 static void ssh2_protocol(Ssh ssh
, void *vin
, int inlen
,
9529 struct Packet
*pktin
)
9531 unsigned char *in
= (unsigned char *)vin
;
9532 if (ssh
->state
== SSH_STATE_CLOSED
)
9536 ssh
->incoming_data_size
+= pktin
->encrypted_len
;
9537 if (!ssh
->kex_in_progress
&&
9538 ssh
->max_data_size
!= 0 &&
9539 ssh
->incoming_data_size
> ssh
->max_data_size
)
9540 do_ssh2_transport(ssh
, "too much data received", -1, NULL
);
9544 ssh
->packet_dispatch
[pktin
->type
](ssh
, pktin
);
9545 else if (!ssh
->protocol_initial_phase_done
)
9546 do_ssh2_transport(ssh
, in
, inlen
, pktin
);
9548 do_ssh2_authconn(ssh
, in
, inlen
, pktin
);
9551 static void ssh_cache_conf_values(Ssh ssh
)
9553 ssh
->logomitdata
= conf_get_int(ssh
->conf
, CONF_logomitdata
);
9557 * Called to set up the connection.
9559 * Returns an error message, or NULL on success.
9561 static const char *ssh_init(void *frontend_handle
, void **backend_handle
,
9562 Conf
*conf
, char *host
, int port
, char **realhost
,
9563 int nodelay
, int keepalive
)
9568 ssh
= snew(struct ssh_tag
);
9569 ssh
->conf
= conf_copy(conf
);
9570 ssh_cache_conf_values(ssh
);
9571 ssh
->version
= 0; /* when not ready yet */
9574 ssh
->v1_cipher_ctx
= NULL
;
9575 ssh
->crcda_ctx
= NULL
;
9576 ssh
->cscipher
= NULL
;
9577 ssh
->cs_cipher_ctx
= NULL
;
9578 ssh
->sccipher
= NULL
;
9579 ssh
->sc_cipher_ctx
= NULL
;
9581 ssh
->cs_mac_ctx
= NULL
;
9583 ssh
->sc_mac_ctx
= NULL
;
9585 ssh
->cs_comp_ctx
= NULL
;
9587 ssh
->sc_comp_ctx
= NULL
;
9589 ssh
->kex_ctx
= NULL
;
9590 ssh
->hostkey
= NULL
;
9592 ssh
->close_expected
= FALSE
;
9593 ssh
->clean_exit
= FALSE
;
9594 ssh
->state
= SSH_STATE_PREPACKET
;
9595 ssh
->size_needed
= FALSE
;
9596 ssh
->eof_needed
= FALSE
;
9599 ssh
->deferred_send_data
= NULL
;
9600 ssh
->deferred_len
= 0;
9601 ssh
->deferred_size
= 0;
9602 ssh
->fallback_cmd
= 0;
9603 ssh
->pkt_kctx
= SSH2_PKTCTX_NOKEX
;
9604 ssh
->pkt_actx
= SSH2_PKTCTX_NOAUTH
;
9605 ssh
->x11disp
= NULL
;
9606 ssh
->v1_compressing
= FALSE
;
9607 ssh
->v2_outgoing_sequence
= 0;
9608 ssh
->ssh1_rdpkt_crstate
= 0;
9609 ssh
->ssh2_rdpkt_crstate
= 0;
9610 ssh
->ssh_gotdata_crstate
= 0;
9611 ssh
->do_ssh1_connection_crstate
= 0;
9612 ssh
->do_ssh_init_state
= NULL
;
9613 ssh
->do_ssh1_login_state
= NULL
;
9614 ssh
->do_ssh2_transport_state
= NULL
;
9615 ssh
->do_ssh2_authconn_state
= NULL
;
9618 ssh
->mainchan
= NULL
;
9619 ssh
->throttled_all
= 0;
9620 ssh
->v1_stdout_throttling
= 0;
9622 ssh
->queuelen
= ssh
->queuesize
= 0;
9623 ssh
->queueing
= FALSE
;
9624 ssh
->qhead
= ssh
->qtail
= NULL
;
9625 ssh
->deferred_rekey_reason
= NULL
;
9626 bufchain_init(&ssh
->queued_incoming_data
);
9627 ssh
->frozen
= FALSE
;
9628 ssh
->username
= NULL
;
9629 ssh
->sent_console_eof
= FALSE
;
9630 ssh
->got_pty
= FALSE
;
9632 *backend_handle
= ssh
;
9635 if (crypto_startup() == 0)
9636 return "Microsoft high encryption pack not installed!";
9639 ssh
->frontend
= frontend_handle
;
9640 ssh
->term_width
= conf_get_int(ssh
->conf
, CONF_width
);
9641 ssh
->term_height
= conf_get_int(ssh
->conf
, CONF_height
);
9643 ssh
->channels
= NULL
;
9644 ssh
->rportfwds
= NULL
;
9645 ssh
->portfwds
= NULL
;
9650 ssh
->conn_throttle_count
= 0;
9651 ssh
->overall_bufsize
= 0;
9652 ssh
->fallback_cmd
= 0;
9654 ssh
->protocol
= NULL
;
9656 ssh
->protocol_initial_phase_done
= FALSE
;
9660 ssh
->incoming_data_size
= ssh
->outgoing_data_size
=
9661 ssh
->deferred_data_size
= 0L;
9662 ssh
->max_data_size
= parse_blocksize(conf_get_str(ssh
->conf
,
9663 CONF_ssh_rekey_data
));
9664 ssh
->kex_in_progress
= FALSE
;
9667 ssh
->gsslibs
= NULL
;
9670 p
= connect_to_host(ssh
, host
, port
, realhost
, nodelay
, keepalive
);
9679 static void ssh_free(void *handle
)
9681 Ssh ssh
= (Ssh
) handle
;
9682 struct ssh_channel
*c
;
9683 struct ssh_rportfwd
*pf
;
9685 if (ssh
->v1_cipher_ctx
)
9686 ssh
->cipher
->free_context(ssh
->v1_cipher_ctx
);
9687 if (ssh
->cs_cipher_ctx
)
9688 ssh
->cscipher
->free_context(ssh
->cs_cipher_ctx
);
9689 if (ssh
->sc_cipher_ctx
)
9690 ssh
->sccipher
->free_context(ssh
->sc_cipher_ctx
);
9691 if (ssh
->cs_mac_ctx
)
9692 ssh
->csmac
->free_context(ssh
->cs_mac_ctx
);
9693 if (ssh
->sc_mac_ctx
)
9694 ssh
->scmac
->free_context(ssh
->sc_mac_ctx
);
9695 if (ssh
->cs_comp_ctx
) {
9697 ssh
->cscomp
->compress_cleanup(ssh
->cs_comp_ctx
);
9699 zlib_compress_cleanup(ssh
->cs_comp_ctx
);
9701 if (ssh
->sc_comp_ctx
) {
9703 ssh
->sccomp
->decompress_cleanup(ssh
->sc_comp_ctx
);
9705 zlib_decompress_cleanup(ssh
->sc_comp_ctx
);
9708 dh_cleanup(ssh
->kex_ctx
);
9709 sfree(ssh
->savedhost
);
9711 while (ssh
->queuelen
-- > 0)
9712 ssh_free_packet(ssh
->queue
[ssh
->queuelen
]);
9715 while (ssh
->qhead
) {
9716 struct queued_handler
*qh
= ssh
->qhead
;
9717 ssh
->qhead
= qh
->next
;
9720 ssh
->qhead
= ssh
->qtail
= NULL
;
9722 if (ssh
->channels
) {
9723 while ((c
= delpos234(ssh
->channels
, 0)) != NULL
) {
9726 if (c
->u
.x11
.s
!= NULL
)
9727 x11_close(c
->u
.x11
.s
);
9730 case CHAN_SOCKDATA_DORMANT
:
9731 if (c
->u
.pfd
.s
!= NULL
)
9732 pfd_close(c
->u
.pfd
.s
);
9735 if (ssh
->version
== 2) {
9736 struct outstanding_channel_request
*ocr
, *nocr
;
9737 ocr
= c
->v
.v2
.chanreq_head
;
9739 ocr
->handler(c
, NULL
, ocr
->ctx
);
9744 bufchain_clear(&c
->v
.v2
.outbuffer
);
9748 freetree234(ssh
->channels
);
9749 ssh
->channels
= NULL
;
9752 if (ssh
->rportfwds
) {
9753 while ((pf
= delpos234(ssh
->rportfwds
, 0)) != NULL
)
9755 freetree234(ssh
->rportfwds
);
9756 ssh
->rportfwds
= NULL
;
9758 sfree(ssh
->deferred_send_data
);
9760 x11_free_display(ssh
->x11disp
);
9761 sfree(ssh
->do_ssh_init_state
);
9762 sfree(ssh
->do_ssh1_login_state
);
9763 sfree(ssh
->do_ssh2_transport_state
);
9764 sfree(ssh
->do_ssh2_authconn_state
);
9767 sfree(ssh
->fullhostname
);
9768 if (ssh
->crcda_ctx
) {
9769 crcda_free_context(ssh
->crcda_ctx
);
9770 ssh
->crcda_ctx
= NULL
;
9773 ssh_do_close(ssh
, TRUE
);
9774 expire_timer_context(ssh
);
9776 pinger_free(ssh
->pinger
);
9777 bufchain_clear(&ssh
->queued_incoming_data
);
9778 sfree(ssh
->username
);
9779 conf_free(ssh
->conf
);
9782 ssh_gss_cleanup(ssh
->gsslibs
);
9790 * Reconfigure the SSH backend.
9792 static void ssh_reconfig(void *handle
, Conf
*conf
)
9794 Ssh ssh
= (Ssh
) handle
;
9795 char *rekeying
= NULL
, rekey_mandatory
= FALSE
;
9796 unsigned long old_max_data_size
;
9799 pinger_reconfig(ssh
->pinger
, ssh
->conf
, conf
);
9801 ssh_setup_portfwd(ssh
, conf
);
9803 rekey_time
= conf_get_int(conf
, CONF_ssh_rekey_time
);
9804 if (conf_get_int(ssh
->conf
, CONF_ssh_rekey_time
) != rekey_time
&&
9806 long new_next
= ssh
->last_rekey
+ rekey_time
*60*TICKSPERSEC
;
9807 long now
= GETTICKCOUNT();
9809 if (new_next
- now
< 0) {
9810 rekeying
= "timeout shortened";
9812 ssh
->next_rekey
= schedule_timer(new_next
- now
, ssh2_timer
, ssh
);
9816 old_max_data_size
= ssh
->max_data_size
;
9817 ssh
->max_data_size
= parse_blocksize(conf_get_str(ssh
->conf
,
9818 CONF_ssh_rekey_data
));
9819 if (old_max_data_size
!= ssh
->max_data_size
&&
9820 ssh
->max_data_size
!= 0) {
9821 if (ssh
->outgoing_data_size
> ssh
->max_data_size
||
9822 ssh
->incoming_data_size
> ssh
->max_data_size
)
9823 rekeying
= "data limit lowered";
9826 if (conf_get_int(ssh
->conf
, CONF_compression
) !=
9827 conf_get_int(conf
, CONF_compression
)) {
9828 rekeying
= "compression setting changed";
9829 rekey_mandatory
= TRUE
;
9832 for (i
= 0; i
< CIPHER_MAX
; i
++)
9833 if (conf_get_int_int(ssh
->conf
, CONF_ssh_cipherlist
, i
) !=
9834 conf_get_int_int(conf
, CONF_ssh_cipherlist
, i
)) {
9835 rekeying
= "cipher settings changed";
9836 rekey_mandatory
= TRUE
;
9838 if (conf_get_int(ssh
->conf
, CONF_ssh2_des_cbc
) !=
9839 conf_get_int(conf
, CONF_ssh2_des_cbc
)) {
9840 rekeying
= "cipher settings changed";
9841 rekey_mandatory
= TRUE
;
9844 conf_free(ssh
->conf
);
9845 ssh
->conf
= conf_copy(conf
);
9846 ssh_cache_conf_values(ssh
);
9849 if (!ssh
->kex_in_progress
) {
9850 do_ssh2_transport(ssh
, rekeying
, -1, NULL
);
9851 } else if (rekey_mandatory
) {
9852 ssh
->deferred_rekey_reason
= rekeying
;
9858 * Called to send data down the SSH connection.
9860 static int ssh_send(void *handle
, char *buf
, int len
)
9862 Ssh ssh
= (Ssh
) handle
;
9864 if (ssh
== NULL
|| ssh
->s
== NULL
|| ssh
->protocol
== NULL
)
9867 ssh
->protocol(ssh
, (unsigned char *)buf
, len
, 0);
9869 return ssh_sendbuffer(ssh
);
9873 * Called to query the current amount of buffered stdin data.
9875 static int ssh_sendbuffer(void *handle
)
9877 Ssh ssh
= (Ssh
) handle
;
9880 if (ssh
== NULL
|| ssh
->s
== NULL
|| ssh
->protocol
== NULL
)
9884 * If the SSH socket itself has backed up, add the total backup
9885 * size on that to any individual buffer on the stdin channel.
9888 if (ssh
->throttled_all
)
9889 override_value
= ssh
->overall_bufsize
;
9891 if (ssh
->version
== 1) {
9892 return override_value
;
9893 } else if (ssh
->version
== 2) {
9895 return override_value
;
9897 return (override_value
+
9898 bufchain_size(&ssh
->mainchan
->v
.v2
.outbuffer
));
9905 * Called to set the size of the window from SSH's POV.
9907 static void ssh_size(void *handle
, int width
, int height
)
9909 Ssh ssh
= (Ssh
) handle
;
9910 struct Packet
*pktout
;
9912 ssh
->term_width
= width
;
9913 ssh
->term_height
= height
;
9915 switch (ssh
->state
) {
9916 case SSH_STATE_BEFORE_SIZE
:
9917 case SSH_STATE_PREPACKET
:
9918 case SSH_STATE_CLOSED
:
9919 break; /* do nothing */
9920 case SSH_STATE_INTERMED
:
9921 ssh
->size_needed
= TRUE
; /* buffer for later */
9923 case SSH_STATE_SESSION
:
9924 if (!conf_get_int(ssh
->conf
, CONF_nopty
)) {
9925 if (ssh
->version
== 1) {
9926 send_packet(ssh
, SSH1_CMSG_WINDOW_SIZE
,
9927 PKT_INT
, ssh
->term_height
,
9928 PKT_INT
, ssh
->term_width
,
9929 PKT_INT
, 0, PKT_INT
, 0, PKT_END
);
9930 } else if (ssh
->mainchan
) {
9931 pktout
= ssh2_chanreq_init(ssh
->mainchan
, "window-change",
9933 ssh2_pkt_adduint32(pktout
, ssh
->term_width
);
9934 ssh2_pkt_adduint32(pktout
, ssh
->term_height
);
9935 ssh2_pkt_adduint32(pktout
, 0);
9936 ssh2_pkt_adduint32(pktout
, 0);
9937 ssh2_pkt_send(ssh
, pktout
);
9945 * Return a list of the special codes that make sense in this
9948 static const struct telnet_special
*ssh_get_specials(void *handle
)
9950 static const struct telnet_special ssh1_ignore_special
[] = {
9951 {"IGNORE message", TS_NOP
}
9953 static const struct telnet_special ssh2_ignore_special
[] = {
9954 {"IGNORE message", TS_NOP
},
9956 static const struct telnet_special ssh2_rekey_special
[] = {
9957 {"Repeat key exchange", TS_REKEY
},
9959 static const struct telnet_special ssh2_session_specials
[] = {
9962 /* These are the signal names defined by RFC 4254.
9963 * They include all the ISO C signals, but are a subset of the POSIX
9964 * required signals. */
9965 {"SIGINT (Interrupt)", TS_SIGINT
},
9966 {"SIGTERM (Terminate)", TS_SIGTERM
},
9967 {"SIGKILL (Kill)", TS_SIGKILL
},
9968 {"SIGQUIT (Quit)", TS_SIGQUIT
},
9969 {"SIGHUP (Hangup)", TS_SIGHUP
},
9970 {"More signals", TS_SUBMENU
},
9971 {"SIGABRT", TS_SIGABRT
}, {"SIGALRM", TS_SIGALRM
},
9972 {"SIGFPE", TS_SIGFPE
}, {"SIGILL", TS_SIGILL
},
9973 {"SIGPIPE", TS_SIGPIPE
}, {"SIGSEGV", TS_SIGSEGV
},
9974 {"SIGUSR1", TS_SIGUSR1
}, {"SIGUSR2", TS_SIGUSR2
},
9977 static const struct telnet_special specials_end
[] = {
9980 /* XXX review this length for any changes: */
9981 static struct telnet_special ssh_specials
[lenof(ssh2_ignore_special
) +
9982 lenof(ssh2_rekey_special
) +
9983 lenof(ssh2_session_specials
) +
9984 lenof(specials_end
)];
9985 Ssh ssh
= (Ssh
) handle
;
9987 #define ADD_SPECIALS(name) \
9989 assert((i + lenof(name)) <= lenof(ssh_specials)); \
9990 memcpy(&ssh_specials[i], name, sizeof name); \
9994 if (ssh
->version
== 1) {
9995 /* Don't bother offering IGNORE if we've decided the remote
9996 * won't cope with it, since we wouldn't bother sending it if
9998 if (!(ssh
->remote_bugs
& BUG_CHOKES_ON_SSH1_IGNORE
))
9999 ADD_SPECIALS(ssh1_ignore_special
);
10000 } else if (ssh
->version
== 2) {
10001 if (!(ssh
->remote_bugs
& BUG_CHOKES_ON_SSH2_IGNORE
))
10002 ADD_SPECIALS(ssh2_ignore_special
);
10003 if (!(ssh
->remote_bugs
& BUG_SSH2_REKEY
))
10004 ADD_SPECIALS(ssh2_rekey_special
);
10006 ADD_SPECIALS(ssh2_session_specials
);
10007 } /* else we're not ready yet */
10010 ADD_SPECIALS(specials_end
);
10011 return ssh_specials
;
10015 #undef ADD_SPECIALS
10019 * Send special codes. TS_EOF is useful for `plink', so you
10020 * can send an EOF and collect resulting output (e.g. `plink
10023 static void ssh_special(void *handle
, Telnet_Special code
)
10025 Ssh ssh
= (Ssh
) handle
;
10026 struct Packet
*pktout
;
10028 if (code
== TS_EOF
) {
10029 if (ssh
->state
!= SSH_STATE_SESSION
) {
10031 * Buffer the EOF in case we are pre-SESSION, so we can
10032 * send it as soon as we reach SESSION.
10034 if (code
== TS_EOF
)
10035 ssh
->eof_needed
= TRUE
;
10038 if (ssh
->version
== 1) {
10039 send_packet(ssh
, SSH1_CMSG_EOF
, PKT_END
);
10040 } else if (ssh
->mainchan
) {
10041 sshfwd_write_eof(ssh
->mainchan
);
10042 ssh
->send_ok
= 0; /* now stop trying to read from stdin */
10044 logevent("Sent EOF message");
10045 } else if (code
== TS_PING
|| code
== TS_NOP
) {
10046 if (ssh
->state
== SSH_STATE_CLOSED
10047 || ssh
->state
== SSH_STATE_PREPACKET
) return;
10048 if (ssh
->version
== 1) {
10049 if (!(ssh
->remote_bugs
& BUG_CHOKES_ON_SSH1_IGNORE
))
10050 send_packet(ssh
, SSH1_MSG_IGNORE
, PKT_STR
, "", PKT_END
);
10052 if (!(ssh
->remote_bugs
& BUG_CHOKES_ON_SSH2_IGNORE
)) {
10053 pktout
= ssh2_pkt_init(SSH2_MSG_IGNORE
);
10054 ssh2_pkt_addstring_start(pktout
);
10055 ssh2_pkt_send_noqueue(ssh
, pktout
);
10058 } else if (code
== TS_REKEY
) {
10059 if (!ssh
->kex_in_progress
&& ssh
->version
== 2) {
10060 do_ssh2_transport(ssh
, "at user request", -1, NULL
);
10062 } else if (code
== TS_BRK
) {
10063 if (ssh
->state
== SSH_STATE_CLOSED
10064 || ssh
->state
== SSH_STATE_PREPACKET
) return;
10065 if (ssh
->version
== 1) {
10066 logevent("Unable to send BREAK signal in SSH-1");
10067 } else if (ssh
->mainchan
) {
10068 pktout
= ssh2_chanreq_init(ssh
->mainchan
, "break", NULL
, NULL
);
10069 ssh2_pkt_adduint32(pktout
, 0); /* default break length */
10070 ssh2_pkt_send(ssh
, pktout
);
10073 /* Is is a POSIX signal? */
10074 char *signame
= NULL
;
10075 if (code
== TS_SIGABRT
) signame
= "ABRT";
10076 if (code
== TS_SIGALRM
) signame
= "ALRM";
10077 if (code
== TS_SIGFPE
) signame
= "FPE";
10078 if (code
== TS_SIGHUP
) signame
= "HUP";
10079 if (code
== TS_SIGILL
) signame
= "ILL";
10080 if (code
== TS_SIGINT
) signame
= "INT";
10081 if (code
== TS_SIGKILL
) signame
= "KILL";
10082 if (code
== TS_SIGPIPE
) signame
= "PIPE";
10083 if (code
== TS_SIGQUIT
) signame
= "QUIT";
10084 if (code
== TS_SIGSEGV
) signame
= "SEGV";
10085 if (code
== TS_SIGTERM
) signame
= "TERM";
10086 if (code
== TS_SIGUSR1
) signame
= "USR1";
10087 if (code
== TS_SIGUSR2
) signame
= "USR2";
10088 /* The SSH-2 protocol does in principle support arbitrary named
10089 * signals, including signame@domain, but we don't support those. */
10091 /* It's a signal. */
10092 if (ssh
->version
== 2 && ssh
->mainchan
) {
10093 pktout
= ssh2_chanreq_init(ssh
->mainchan
, "signal", NULL
, NULL
);
10094 ssh2_pkt_addstring(pktout
, signame
);
10095 ssh2_pkt_send(ssh
, pktout
);
10096 logeventf(ssh
, "Sent signal SIG%s", signame
);
10099 /* Never heard of it. Do nothing */
10104 void *new_sock_channel(void *handle
, Socket s
)
10106 Ssh ssh
= (Ssh
) handle
;
10107 struct ssh_channel
*c
;
10108 c
= snew(struct ssh_channel
);
10111 ssh2_channel_init(c
);
10112 c
->halfopen
= TRUE
;
10113 c
->type
= CHAN_SOCKDATA_DORMANT
;/* identify channel type */
10115 add234(ssh
->channels
, c
);
10120 * This is called when stdout/stderr (the entity to which
10121 * from_backend sends data) manages to clear some backlog.
10123 static void ssh_unthrottle(void *handle
, int bufsize
)
10125 Ssh ssh
= (Ssh
) handle
;
10128 if (ssh
->version
== 1) {
10129 if (ssh
->v1_stdout_throttling
&& bufsize
< SSH1_BUFFER_LIMIT
) {
10130 ssh
->v1_stdout_throttling
= 0;
10131 ssh_throttle_conn(ssh
, -1);
10134 if (ssh
->mainchan
) {
10135 ssh2_set_window(ssh
->mainchan
,
10136 bufsize
< ssh
->mainchan
->v
.v2
.locmaxwin ?
10137 ssh
->mainchan
->v
.v2
.locmaxwin
- bufsize
: 0);
10138 if (conf_get_int(ssh
->conf
, CONF_ssh_simple
))
10141 buflimit
= ssh
->mainchan
->v
.v2
.locmaxwin
;
10142 if (ssh
->mainchan
->throttling_conn
&& bufsize
<= buflimit
) {
10143 ssh
->mainchan
->throttling_conn
= 0;
10144 ssh_throttle_conn(ssh
, -1);
10150 * Now process any SSH connection data that was stashed in our
10151 * queue while we were frozen.
10153 ssh_process_queued_incoming_data(ssh
);
10156 void ssh_send_port_open(void *channel
, char *hostname
, int port
, char *org
)
10158 struct ssh_channel
*c
= (struct ssh_channel
*)channel
;
10160 struct Packet
*pktout
;
10162 logeventf(ssh
, "Opening forwarded connection to %s:%d", hostname
, port
);
10164 if (ssh
->version
== 1) {
10165 send_packet(ssh
, SSH1_MSG_PORT_OPEN
,
10166 PKT_INT
, c
->localid
,
10169 /* PKT_STR, <org:orgport>, */
10172 pktout
= ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN
);
10173 ssh2_pkt_addstring(pktout
, "direct-tcpip");
10174 ssh2_pkt_adduint32(pktout
, c
->localid
);
10175 ssh2_pkt_adduint32(pktout
, c
->v
.v2
.locwindow
);/* our window size */
10176 ssh2_pkt_adduint32(pktout
, OUR_V2_MAXPKT
); /* our max pkt size */
10177 ssh2_pkt_addstring(pktout
, hostname
);
10178 ssh2_pkt_adduint32(pktout
, port
);
10180 * We make up values for the originator data; partly it's
10181 * too much hassle to keep track, and partly I'm not
10182 * convinced the server should be told details like that
10183 * about my local network configuration.
10184 * The "originator IP address" is syntactically a numeric
10185 * IP address, and some servers (e.g., Tectia) get upset
10186 * if it doesn't match this syntax.
10188 ssh2_pkt_addstring(pktout
, "0.0.0.0");
10189 ssh2_pkt_adduint32(pktout
, 0);
10190 ssh2_pkt_send(ssh
, pktout
);
10194 static int ssh_connected(void *handle
)
10196 Ssh ssh
= (Ssh
) handle
;
10197 return ssh
->s
!= NULL
;
10200 static int ssh_sendok(void *handle
)
10202 Ssh ssh
= (Ssh
) handle
;
10203 return ssh
->send_ok
;
10206 static int ssh_ldisc(void *handle
, int option
)
10208 Ssh ssh
= (Ssh
) handle
;
10209 if (option
== LD_ECHO
)
10210 return ssh
->echoing
;
10211 if (option
== LD_EDIT
)
10212 return ssh
->editing
;
10216 static void ssh_provide_ldisc(void *handle
, void *ldisc
)
10218 Ssh ssh
= (Ssh
) handle
;
10219 ssh
->ldisc
= ldisc
;
10222 static void ssh_provide_logctx(void *handle
, void *logctx
)
10224 Ssh ssh
= (Ssh
) handle
;
10225 ssh
->logctx
= logctx
;
10228 static int ssh_return_exitcode(void *handle
)
10230 Ssh ssh
= (Ssh
) handle
;
10231 if (ssh
->s
!= NULL
)
10234 return (ssh
->exitcode
>= 0 ? ssh
->exitcode
: INT_MAX
);
10238 * cfg_info for SSH is the currently running version of the
10239 * protocol. (1 for 1; 2 for 2; 0 for not-decided-yet.)
10241 static int ssh_cfg_info(void *handle
)
10243 Ssh ssh
= (Ssh
) handle
;
10244 return ssh
->version
;
10248 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
10249 * that fails. This variable is the means by which scp.c can reach
10250 * into the SSH code and find out which one it got.
10252 extern int ssh_fallback_cmd(void *handle
)
10254 Ssh ssh
= (Ssh
) handle
;
10255 return ssh
->fallback_cmd
;
10258 Backend ssh_backend
= {
10268 ssh_return_exitcode
,
10272 ssh_provide_logctx
,