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:;
436 if (!ssh->t) ssh->t = snew(struct t); \
438 #define crFinish(z) } *crLine = 0; return (z); }
439 #define crFinishV } *crLine = 0; return; }
440 #define crReturn(z) \
442 *crLine =__LINE__; return (z); case __LINE__:;\
446 *crLine=__LINE__; return; case __LINE__:;\
448 #define crStop(z) do{ *crLine = 0; return (z); }while(0)
449 #define crStopV do{ *crLine = 0; return; }while(0)
450 #define crWaitUntil(c) do { crReturn(0); } while (!(c))
451 #define crWaitUntilV(c) do { crReturnV; } while (!(c))
453 typedef struct ssh_tag
*Ssh
;
456 static struct Packet
*ssh1_pkt_init(int pkt_type
);
457 static struct Packet
*ssh2_pkt_init(int pkt_type
);
458 static void ssh_pkt_ensure(struct Packet
*, int length
);
459 static void ssh_pkt_adddata(struct Packet
*, void *data
, int len
);
460 static void ssh_pkt_addbyte(struct Packet
*, unsigned char value
);
461 static void ssh2_pkt_addbool(struct Packet
*, unsigned char value
);
462 static void ssh_pkt_adduint32(struct Packet
*, unsigned long value
);
463 static void ssh_pkt_addstring_start(struct Packet
*);
464 static void ssh_pkt_addstring_str(struct Packet
*, char *data
);
465 static void ssh_pkt_addstring_data(struct Packet
*, char *data
, int len
);
466 static void ssh_pkt_addstring(struct Packet
*, char *data
);
467 static unsigned char *ssh2_mpint_fmt(Bignum b
, int *len
);
468 static void ssh1_pkt_addmp(struct Packet
*, Bignum b
);
469 static void ssh2_pkt_addmp(struct Packet
*, Bignum b
);
470 static int ssh2_pkt_construct(Ssh
, struct Packet
*);
471 static void ssh2_pkt_send(Ssh
, struct Packet
*);
472 static void ssh2_pkt_send_noqueue(Ssh
, struct Packet
*);
473 static int do_ssh1_login(Ssh ssh
, unsigned char *in
, int inlen
,
474 struct Packet
*pktin
);
475 static void do_ssh2_authconn(Ssh ssh
, unsigned char *in
, int inlen
,
476 struct Packet
*pktin
);
477 static void ssh2_channel_check_close(struct ssh_channel
*c
);
478 static void ssh_channel_destroy(struct ssh_channel
*c
);
481 * Buffer management constants. There are several of these for
482 * various different purposes:
484 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
485 * on a local data stream before we throttle the whole SSH
486 * connection (in SSH-1 only). Throttling the whole connection is
487 * pretty drastic so we set this high in the hope it won't
490 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
491 * on the SSH connection itself before we defensively throttle
492 * _all_ local data streams. This is pretty drastic too (though
493 * thankfully unlikely in SSH-2 since the window mechanism should
494 * ensure that the server never has any need to throttle its end
495 * of the connection), so we set this high as well.
497 * - OUR_V2_WINSIZE is the maximum window size we present on SSH-2
500 * - OUR_V2_BIGWIN is the window size we advertise for the only
501 * channel in a simple connection. It must be <= INT_MAX.
503 * - OUR_V2_MAXPKT is the official "maximum packet size" we send
504 * to the remote side. This actually has nothing to do with the
505 * size of the _packet_, but is instead a limit on the amount
506 * of data we're willing to receive in a single SSH2 channel
509 * - OUR_V2_PACKETLIMIT is actually the maximum size of SSH
510 * _packet_ we're prepared to cope with. It must be a multiple
511 * of the cipher block size, and must be at least 35000.
514 #define SSH1_BUFFER_LIMIT 32768
515 #define SSH_MAX_BACKLOG 32768
516 #define OUR_V2_WINSIZE 16384
517 #define OUR_V2_BIGWIN 0x7fffffff
518 #define OUR_V2_MAXPKT 0x4000UL
519 #define OUR_V2_PACKETLIMIT 0x9000UL
521 const static struct ssh_signkey
*hostkey_algs
[] = { &ssh_rsa
, &ssh_dss
};
523 const static struct ssh_mac
*macs
[] = {
524 &ssh_hmac_sha1
, &ssh_hmac_sha1_96
, &ssh_hmac_md5
526 const static struct ssh_mac
*buggymacs
[] = {
527 &ssh_hmac_sha1_buggy
, &ssh_hmac_sha1_96_buggy
, &ssh_hmac_md5
530 static void *ssh_comp_none_init(void)
534 static void ssh_comp_none_cleanup(void *handle
)
537 static int ssh_comp_none_block(void *handle
, unsigned char *block
, int len
,
538 unsigned char **outblock
, int *outlen
)
542 static int ssh_comp_none_disable(void *handle
)
546 const static struct ssh_compress ssh_comp_none
= {
548 ssh_comp_none_init
, ssh_comp_none_cleanup
, ssh_comp_none_block
,
549 ssh_comp_none_init
, ssh_comp_none_cleanup
, ssh_comp_none_block
,
550 ssh_comp_none_disable
, NULL
552 extern const struct ssh_compress ssh_zlib
;
553 const static struct ssh_compress
*compressions
[] = {
554 &ssh_zlib
, &ssh_comp_none
557 enum { /* channel types */
562 CHAN_SOCKDATA_DORMANT
, /* one the remote hasn't confirmed */
564 * CHAN_ZOMBIE is used to indicate a channel for which we've
565 * already destroyed the local data source: for instance, if a
566 * forwarded port experiences a socket error on the local side, we
567 * immediately destroy its local socket and turn the SSH channel
574 * little structure to keep track of outstanding WINDOW_ADJUSTs
582 * 2-3-4 tree storing channels.
585 Ssh ssh
; /* pointer back to main context */
586 unsigned remoteid
, localid
;
588 /* True if we opened this channel but server hasn't confirmed. */
591 * In SSH-1, this value contains four bits:
593 * 1 We have sent SSH1_MSG_CHANNEL_CLOSE.
594 * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
595 * 4 We have received SSH1_MSG_CHANNEL_CLOSE.
596 * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
598 * A channel is completely finished with when all four bits are set.
600 * In SSH-2, the four bits mean:
602 * 1 We have sent SSH2_MSG_CHANNEL_EOF.
603 * 2 We have sent SSH2_MSG_CHANNEL_CLOSE.
604 * 4 We have received SSH2_MSG_CHANNEL_EOF.
605 * 8 We have received SSH2_MSG_CHANNEL_CLOSE.
607 * A channel is completely finished with when we have both sent
608 * and received CLOSE.
610 * The symbolic constants below use the SSH-2 terminology, which
611 * is a bit confusing in SSH-1, but we have to use _something_.
613 #define CLOSES_SENT_EOF 1
614 #define CLOSES_SENT_CLOSE 2
615 #define CLOSES_RCVD_EOF 4
616 #define CLOSES_RCVD_CLOSE 8
620 * This flag indicates that an EOF is pending on the outgoing side
621 * of the channel: that is, wherever we're getting the data for
622 * this channel has sent us some data followed by EOF. We can't
623 * actually send the EOF until we've finished sending the data, so
624 * we set this flag instead to remind us to do so once our buffer
630 * True if this channel is causing the underlying connection to be
635 struct ssh2_data_channel
{
637 unsigned remwindow
, remmaxpkt
;
638 /* locwindow is signed so we can cope with excess data. */
639 int locwindow
, locmaxwin
;
641 * remlocwin is the amount of local window that we think
642 * the remote end had available to it after it sent the
643 * last data packet or window adjust ack.
647 * These store the list of window adjusts that haven't
650 struct winadj
*winadj_head
, *winadj_tail
;
651 enum { THROTTLED
, UNTHROTTLING
, UNTHROTTLED
} throttle_state
;
655 struct ssh_agent_channel
{
656 unsigned char *message
;
657 unsigned char msglen
[4];
658 unsigned lensofar
, totallen
;
660 struct ssh_x11_channel
{
663 struct ssh_pfd_channel
{
670 * 2-3-4 tree storing remote->local port forwardings. SSH-1 and SSH-2
671 * use this structure in different ways, reflecting SSH-2's
672 * altogether saner approach to port forwarding.
674 * In SSH-1, you arrange a remote forwarding by sending the server
675 * the remote port number, and the local destination host:port.
676 * When a connection comes in, the server sends you back that
677 * host:port pair, and you connect to it. This is a ready-made
678 * security hole if you're not on the ball: a malicious server
679 * could send you back _any_ host:port pair, so if you trustingly
680 * connect to the address it gives you then you've just opened the
681 * entire inside of your corporate network just by connecting
682 * through it to a dodgy SSH server. Hence, we must store a list of
683 * host:port pairs we _are_ trying to forward to, and reject a
684 * connection request from the server if it's not in the list.
686 * In SSH-2, each side of the connection minds its own business and
687 * doesn't send unnecessary information to the other. You arrange a
688 * remote forwarding by sending the server just the remote port
689 * number. When a connection comes in, the server tells you which
690 * of its ports was connected to; and _you_ have to remember what
691 * local host:port pair went with that port number.
693 * Hence, in SSH-1 this structure is indexed by destination
694 * host:port pair, whereas in SSH-2 it is indexed by source port.
696 struct ssh_portfwd
; /* forward declaration */
698 struct ssh_rportfwd
{
699 unsigned sport
, dport
;
702 struct ssh_portfwd
*pfrec
;
704 #define free_rportfwd(pf) ( \
705 ((pf) ? (sfree((pf)->sportdesc)) : (void)0 ), sfree(pf) )
708 * Separately to the rportfwd tree (which is for looking up port
709 * open requests from the server), a tree of _these_ structures is
710 * used to keep track of all the currently open port forwardings,
711 * so that we can reconfigure in mid-session if the user requests
715 enum { DESTROY
, KEEP
, CREATE
} status
;
717 unsigned sport
, dport
;
720 struct ssh_rportfwd
*remote
;
724 #define free_portfwd(pf) ( \
725 ((pf) ? (sfree((pf)->saddr), sfree((pf)->daddr), \
726 sfree((pf)->sserv), sfree((pf)->dserv)) : (void)0 ), sfree(pf) )
729 long length
; /* length of `data' actually used */
730 long forcepad
; /* SSH-2: force padding to at least this length */
731 int type
; /* only used for incoming packets */
732 unsigned long sequence
; /* SSH-2 incoming sequence number */
733 unsigned char *data
; /* allocated storage */
734 unsigned char *body
; /* offset of payload within `data' */
735 long savedpos
; /* temporary index into `data' (for strings) */
736 long maxlen
; /* amount of storage allocated for `data' */
737 long encrypted_len
; /* for SSH-2 total-size counting */
740 * State associated with packet logging
744 struct logblank_t
*blanks
;
747 static void ssh1_protocol(Ssh ssh
, void *vin
, int inlen
,
748 struct Packet
*pktin
);
749 static void ssh2_protocol(Ssh ssh
, void *vin
, int inlen
,
750 struct Packet
*pktin
);
751 static void ssh1_protocol_setup(Ssh ssh
);
752 static void ssh2_protocol_setup(Ssh ssh
);
753 static void ssh_size(void *handle
, int width
, int height
);
754 static void ssh_special(void *handle
, Telnet_Special
);
755 static int ssh2_try_send(struct ssh_channel
*c
);
756 static void ssh2_add_channel_data(struct ssh_channel
*c
, char *buf
, int len
);
757 static void ssh_throttle_all(Ssh ssh
, int enable
, int bufsize
);
758 static void ssh2_set_window(struct ssh_channel
*c
, int newwin
);
759 static int ssh_sendbuffer(void *handle
);
760 static int ssh_do_close(Ssh ssh
, int notify_exit
);
761 static unsigned long ssh_pkt_getuint32(struct Packet
*pkt
);
762 static int ssh2_pkt_getbool(struct Packet
*pkt
);
763 static void ssh_pkt_getstring(struct Packet
*pkt
, char **p
, int *length
);
764 static void ssh2_timer(void *ctx
, long now
);
765 static int do_ssh2_transport(Ssh ssh
, void *vin
, int inlen
,
766 struct Packet
*pktin
);
768 struct rdpkt1_state_tag
{
769 long len
, pad
, biglen
, to_read
;
770 unsigned long realcrc
, gotcrc
;
774 struct Packet
*pktin
;
777 struct rdpkt2_state_tag
{
778 long len
, pad
, payload
, packetlen
, maclen
;
781 unsigned long incoming_sequence
;
782 struct Packet
*pktin
;
785 typedef void (*handler_fn_t
)(Ssh ssh
, struct Packet
*pktin
);
786 typedef void (*chandler_fn_t
)(Ssh ssh
, struct Packet
*pktin
, void *ctx
);
788 struct queued_handler
;
789 struct queued_handler
{
791 chandler_fn_t handler
;
793 struct queued_handler
*next
;
797 const struct plug_function_table
*fn
;
798 /* the above field _must_ be first in the structure */
808 unsigned char session_key
[32];
810 int v1_remote_protoflags
;
811 int v1_local_protoflags
;
812 int agentfwd_enabled
;
815 const struct ssh_cipher
*cipher
;
818 const struct ssh2_cipher
*cscipher
, *sccipher
;
819 void *cs_cipher_ctx
, *sc_cipher_ctx
;
820 const struct ssh_mac
*csmac
, *scmac
;
821 void *cs_mac_ctx
, *sc_mac_ctx
;
822 const struct ssh_compress
*cscomp
, *sccomp
;
823 void *cs_comp_ctx
, *sc_comp_ctx
;
824 const struct ssh_kex
*kex
;
825 const struct ssh_signkey
*hostkey
;
826 unsigned char v2_session_id
[SSH2_KEX_MAX_HASH_LEN
];
827 int v2_session_id_len
;
833 int echoing
, editing
;
837 int ospeed
, ispeed
; /* temporaries */
838 int term_width
, term_height
;
840 tree234
*channels
; /* indexed by local id */
841 struct ssh_channel
*mainchan
; /* primary session channel */
842 int ncmode
; /* is primary channel direct-tcpip? */
847 tree234
*rportfwds
, *portfwds
;
851 SSH_STATE_BEFORE_SIZE
,
857 int size_needed
, eof_needed
;
858 int sent_console_eof
;
859 int got_pty
; /* affects EOF behaviour on main channel */
861 struct Packet
**queue
;
862 int queuelen
, queuesize
;
864 unsigned char *deferred_send_data
;
865 int deferred_len
, deferred_size
;
868 * Gross hack: pscp will try to start SFTP but fall back to
869 * scp1 if that fails. This variable is the means by which
870 * scp.c can reach into the SSH code and find out which one it
875 bufchain banner
; /* accumulates banners during do_ssh2_authconn */
880 struct X11Display
*x11disp
;
883 int conn_throttle_count
;
886 int v1_stdout_throttling
;
887 unsigned long v2_outgoing_sequence
;
889 int ssh1_rdpkt_crstate
;
890 int ssh2_rdpkt_crstate
;
891 int do_ssh_init_crstate
;
892 int ssh_gotdata_crstate
;
893 int do_ssh1_login_crstate
;
894 int do_ssh1_connection_crstate
;
895 int do_ssh2_transport_crstate
;
896 int do_ssh2_authconn_crstate
;
898 void *do_ssh_init_state
;
899 void *do_ssh1_login_state
;
900 void *do_ssh2_transport_state
;
901 void *do_ssh2_authconn_state
;
903 struct rdpkt1_state_tag rdpkt1_state
;
904 struct rdpkt2_state_tag rdpkt2_state
;
906 /* SSH-1 and SSH-2 use this for different things, but both use it */
907 int protocol_initial_phase_done
;
909 void (*protocol
) (Ssh ssh
, void *vin
, int inlen
,
911 struct Packet
*(*s_rdpkt
) (Ssh ssh
, unsigned char **data
, int *datalen
);
914 * We maintain our own copy of a Conf structure here. That way,
915 * when we're passed a new one for reconfiguration, we can check
916 * the differences and potentially reconfigure port forwardings
917 * etc in mid-session.
922 * Values cached out of conf so as to avoid the tree234 lookup
923 * cost every time they're used.
928 * Dynamically allocated username string created during SSH
929 * login. Stored in here rather than in the coroutine state so
930 * that it'll be reliably freed if we shut down the SSH session
931 * at some unexpected moment.
936 * Used to transfer data back from async callbacks.
938 void *agent_response
;
939 int agent_response_len
;
943 * The SSH connection can be set as `frozen', meaning we are
944 * not currently accepting incoming data from the network. This
945 * is slightly more serious than setting the _socket_ as
946 * frozen, because we may already have had data passed to us
947 * from the network which we need to delay processing until
948 * after the freeze is lifted, so we also need a bufchain to
952 bufchain queued_incoming_data
;
955 * Dispatch table for packet types that we may have to deal
958 handler_fn_t packet_dispatch
[256];
961 * Queues of one-off handler functions for success/failure
962 * indications from a request.
964 struct queued_handler
*qhead
, *qtail
;
967 * This module deals with sending keepalives.
972 * Track incoming and outgoing data sizes and time, for
975 unsigned long incoming_data_size
, outgoing_data_size
, deferred_data_size
;
976 unsigned long max_data_size
;
978 long next_rekey
, last_rekey
;
979 char *deferred_rekey_reason
; /* points to STATIC string; don't free */
982 * Fully qualified host name, which we need if doing GSSAPI.
988 * GSSAPI libraries for this session.
990 struct ssh_gss_liblist
*gsslibs
;
994 #define logevent(s) logevent(ssh->frontend, s)
996 /* logevent, only printf-formatted. */
997 static void logeventf(Ssh ssh
, const char *fmt
, ...)
1003 buf
= dupvprintf(fmt
, ap
);
1009 #define bombout(msg) \
1011 char *text = dupprintf msg; \
1012 ssh_do_close(ssh, FALSE); \
1014 connection_fatal(ssh->frontend, "%s", text); \
1018 /* Functions to leave bits out of the SSH packet log file. */
1020 static void dont_log_password(Ssh ssh
, struct Packet
*pkt
, int blanktype
)
1022 if (conf_get_int(ssh
->conf
, CONF_logomitpass
))
1023 pkt
->logmode
= blanktype
;
1026 static void dont_log_data(Ssh ssh
, struct Packet
*pkt
, int blanktype
)
1028 if (ssh
->logomitdata
)
1029 pkt
->logmode
= blanktype
;
1032 static void end_log_omission(Ssh ssh
, struct Packet
*pkt
)
1034 pkt
->logmode
= PKTLOG_EMIT
;
1037 /* Helper function for common bits of parsing ttymodes. */
1038 static void parse_ttymodes(Ssh ssh
,
1039 void (*do_mode
)(void *data
, char *mode
, char *val
),
1044 for (val
= conf_get_str_strs(ssh
->conf
, CONF_ttymodes
, NULL
, &key
);
1046 val
= conf_get_str_strs(ssh
->conf
, CONF_ttymodes
, key
, &key
)) {
1048 * val[0] is either 'V', indicating that an explicit value
1049 * follows it, or 'A' indicating that we should pass the
1050 * value through from the local environment via get_ttymode.
1053 val
= get_ttymode(ssh
->frontend
, key
);
1055 val
++; /* skip the 'V' */
1057 do_mode(data
, key
, val
);
1061 static int ssh_channelcmp(void *av
, void *bv
)
1063 struct ssh_channel
*a
= (struct ssh_channel
*) av
;
1064 struct ssh_channel
*b
= (struct ssh_channel
*) bv
;
1065 if (a
->localid
< b
->localid
)
1067 if (a
->localid
> b
->localid
)
1071 static int ssh_channelfind(void *av
, void *bv
)
1073 unsigned *a
= (unsigned *) av
;
1074 struct ssh_channel
*b
= (struct ssh_channel
*) bv
;
1075 if (*a
< b
->localid
)
1077 if (*a
> b
->localid
)
1082 static int ssh_rportcmp_ssh1(void *av
, void *bv
)
1084 struct ssh_rportfwd
*a
= (struct ssh_rportfwd
*) av
;
1085 struct ssh_rportfwd
*b
= (struct ssh_rportfwd
*) bv
;
1087 if ( (i
= strcmp(a
->dhost
, b
->dhost
)) != 0)
1088 return i
< 0 ?
-1 : +1;
1089 if (a
->dport
> b
->dport
)
1091 if (a
->dport
< b
->dport
)
1096 static int ssh_rportcmp_ssh2(void *av
, void *bv
)
1098 struct ssh_rportfwd
*a
= (struct ssh_rportfwd
*) av
;
1099 struct ssh_rportfwd
*b
= (struct ssh_rportfwd
*) bv
;
1101 if (a
->sport
> b
->sport
)
1103 if (a
->sport
< b
->sport
)
1109 * Special form of strcmp which can cope with NULL inputs. NULL is
1110 * defined to sort before even the empty string.
1112 static int nullstrcmp(const char *a
, const char *b
)
1114 if (a
== NULL
&& b
== NULL
)
1120 return strcmp(a
, b
);
1123 static int ssh_portcmp(void *av
, void *bv
)
1125 struct ssh_portfwd
*a
= (struct ssh_portfwd
*) av
;
1126 struct ssh_portfwd
*b
= (struct ssh_portfwd
*) bv
;
1128 if (a
->type
> b
->type
)
1130 if (a
->type
< b
->type
)
1132 if (a
->addressfamily
> b
->addressfamily
)
1134 if (a
->addressfamily
< b
->addressfamily
)
1136 if ( (i
= nullstrcmp(a
->saddr
, b
->saddr
)) != 0)
1137 return i
< 0 ?
-1 : +1;
1138 if (a
->sport
> b
->sport
)
1140 if (a
->sport
< b
->sport
)
1142 if (a
->type
!= 'D') {
1143 if ( (i
= nullstrcmp(a
->daddr
, b
->daddr
)) != 0)
1144 return i
< 0 ?
-1 : +1;
1145 if (a
->dport
> b
->dport
)
1147 if (a
->dport
< b
->dport
)
1153 static int alloc_channel_id(Ssh ssh
)
1155 const unsigned CHANNEL_NUMBER_OFFSET
= 256;
1156 unsigned low
, high
, mid
;
1158 struct ssh_channel
*c
;
1161 * First-fit allocation of channel numbers: always pick the
1162 * lowest unused one. To do this, binary-search using the
1163 * counted B-tree to find the largest channel ID which is in a
1164 * contiguous sequence from the beginning. (Precisely
1165 * everything in that sequence must have ID equal to its tree
1166 * index plus CHANNEL_NUMBER_OFFSET.)
1168 tsize
= count234(ssh
->channels
);
1172 while (high
- low
> 1) {
1173 mid
= (high
+ low
) / 2;
1174 c
= index234(ssh
->channels
, mid
);
1175 if (c
->localid
== mid
+ CHANNEL_NUMBER_OFFSET
)
1176 low
= mid
; /* this one is fine */
1178 high
= mid
; /* this one is past it */
1181 * Now low points to either -1, or the tree index of the
1182 * largest ID in the initial sequence.
1185 unsigned i
= low
+ 1 + CHANNEL_NUMBER_OFFSET
;
1186 assert(NULL
== find234(ssh
->channels
, &i
, ssh_channelfind
));
1188 return low
+ 1 + CHANNEL_NUMBER_OFFSET
;
1191 static void c_write_stderr(int trusted
, const char *buf
, int len
)
1194 for (i
= 0; i
< len
; i
++)
1195 if (buf
[i
] != '\r' && (trusted
|| buf
[i
] == '\n' || (buf
[i
] & 0x60)))
1196 fputc(buf
[i
], stderr
);
1199 static void c_write(Ssh ssh
, const char *buf
, int len
)
1201 if (flags
& FLAG_STDERR
)
1202 c_write_stderr(1, buf
, len
);
1204 from_backend(ssh
->frontend
, 1, buf
, len
);
1207 static void c_write_untrusted(Ssh ssh
, const char *buf
, int len
)
1209 if (flags
& FLAG_STDERR
)
1210 c_write_stderr(0, buf
, len
);
1212 from_backend_untrusted(ssh
->frontend
, buf
, len
);
1215 static void c_write_str(Ssh ssh
, const char *buf
)
1217 c_write(ssh
, buf
, strlen(buf
));
1220 static void ssh_free_packet(struct Packet
*pkt
)
1225 static struct Packet
*ssh_new_packet(void)
1227 struct Packet
*pkt
= snew(struct Packet
);
1229 pkt
->body
= pkt
->data
= NULL
;
1231 pkt
->logmode
= PKTLOG_EMIT
;
1239 * Collect incoming data in the incoming packet buffer.
1240 * Decipher and verify the packet when it is completely read.
1241 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
1242 * Update the *data and *datalen variables.
1243 * Return a Packet structure when a packet is completed.
1245 static struct Packet
*ssh1_rdpkt(Ssh ssh
, unsigned char **data
, int *datalen
)
1247 struct rdpkt1_state_tag
*st
= &ssh
->rdpkt1_state
;
1249 crBegin(ssh
->ssh1_rdpkt_crstate
);
1251 st
->pktin
= ssh_new_packet();
1253 st
->pktin
->type
= 0;
1254 st
->pktin
->length
= 0;
1256 for (st
->i
= st
->len
= 0; st
->i
< 4; st
->i
++) {
1257 while ((*datalen
) == 0)
1259 st
->len
= (st
->len
<< 8) + **data
;
1260 (*data
)++, (*datalen
)--;
1263 st
->pad
= 8 - (st
->len
% 8);
1264 st
->biglen
= st
->len
+ st
->pad
;
1265 st
->pktin
->length
= st
->len
- 5;
1267 if (st
->biglen
< 0) {
1268 bombout(("Extremely large packet length from server suggests"
1269 " data stream corruption"));
1270 ssh_free_packet(st
->pktin
);
1274 st
->pktin
->maxlen
= st
->biglen
;
1275 st
->pktin
->data
= snewn(st
->biglen
+ APIEXTRA
, unsigned char);
1277 st
->to_read
= st
->biglen
;
1278 st
->p
= st
->pktin
->data
;
1279 while (st
->to_read
> 0) {
1280 st
->chunk
= st
->to_read
;
1281 while ((*datalen
) == 0)
1283 if (st
->chunk
> (*datalen
))
1284 st
->chunk
= (*datalen
);
1285 memcpy(st
->p
, *data
, st
->chunk
);
1287 *datalen
-= st
->chunk
;
1289 st
->to_read
-= st
->chunk
;
1292 if (ssh
->cipher
&& detect_attack(ssh
->crcda_ctx
, st
->pktin
->data
,
1293 st
->biglen
, NULL
)) {
1294 bombout(("Network attack (CRC compensation) detected!"));
1295 ssh_free_packet(st
->pktin
);
1300 ssh
->cipher
->decrypt(ssh
->v1_cipher_ctx
, st
->pktin
->data
, st
->biglen
);
1302 st
->realcrc
= crc32_compute(st
->pktin
->data
, st
->biglen
- 4);
1303 st
->gotcrc
= GET_32BIT(st
->pktin
->data
+ st
->biglen
- 4);
1304 if (st
->gotcrc
!= st
->realcrc
) {
1305 bombout(("Incorrect CRC received on packet"));
1306 ssh_free_packet(st
->pktin
);
1310 st
->pktin
->body
= st
->pktin
->data
+ st
->pad
+ 1;
1311 st
->pktin
->savedpos
= 0;
1313 if (ssh
->v1_compressing
) {
1314 unsigned char *decompblk
;
1316 if (!zlib_decompress_block(ssh
->sc_comp_ctx
,
1317 st
->pktin
->body
- 1, st
->pktin
->length
+ 1,
1318 &decompblk
, &decomplen
)) {
1319 bombout(("Zlib decompression encountered invalid data"));
1320 ssh_free_packet(st
->pktin
);
1324 if (st
->pktin
->maxlen
< st
->pad
+ decomplen
) {
1325 st
->pktin
->maxlen
= st
->pad
+ decomplen
;
1326 st
->pktin
->data
= sresize(st
->pktin
->data
,
1327 st
->pktin
->maxlen
+ APIEXTRA
,
1329 st
->pktin
->body
= st
->pktin
->data
+ st
->pad
+ 1;
1332 memcpy(st
->pktin
->body
- 1, decompblk
, decomplen
);
1334 st
->pktin
->length
= decomplen
- 1;
1337 st
->pktin
->type
= st
->pktin
->body
[-1];
1340 * Log incoming packet, possibly omitting sensitive fields.
1344 struct logblank_t blank
;
1345 if (ssh
->logomitdata
) {
1346 int do_blank
= FALSE
, blank_prefix
= 0;
1347 /* "Session data" packets - omit the data field */
1348 if ((st
->pktin
->type
== SSH1_SMSG_STDOUT_DATA
) ||
1349 (st
->pktin
->type
== SSH1_SMSG_STDERR_DATA
)) {
1350 do_blank
= TRUE
; blank_prefix
= 4;
1351 } else if (st
->pktin
->type
== SSH1_MSG_CHANNEL_DATA
) {
1352 do_blank
= TRUE
; blank_prefix
= 8;
1355 blank
.offset
= blank_prefix
;
1356 blank
.len
= st
->pktin
->length
;
1357 blank
.type
= PKTLOG_OMIT
;
1361 log_packet(ssh
->logctx
,
1362 PKT_INCOMING
, st
->pktin
->type
,
1363 ssh1_pkt_type(st
->pktin
->type
),
1364 st
->pktin
->body
, st
->pktin
->length
,
1365 nblanks
, &blank
, NULL
);
1368 crFinish(st
->pktin
);
1371 static struct Packet
*ssh2_rdpkt(Ssh ssh
, unsigned char **data
, int *datalen
)
1373 struct rdpkt2_state_tag
*st
= &ssh
->rdpkt2_state
;
1375 crBegin(ssh
->ssh2_rdpkt_crstate
);
1377 st
->pktin
= ssh_new_packet();
1379 st
->pktin
->type
= 0;
1380 st
->pktin
->length
= 0;
1382 st
->cipherblk
= ssh
->sccipher
->blksize
;
1385 if (st
->cipherblk
< 8)
1387 st
->maclen
= ssh
->scmac ? ssh
->scmac
->len
: 0;
1389 if (ssh
->sccipher
&& (ssh
->sccipher
->flags
& SSH_CIPHER_IS_CBC
) &&
1392 * When dealing with a CBC-mode cipher, we want to avoid the
1393 * possibility of an attacker's tweaking the ciphertext stream
1394 * so as to cause us to feed the same block to the block
1395 * cipher more than once and thus leak information
1396 * (VU#958563). The way we do this is not to take any
1397 * decisions on the basis of anything we've decrypted until
1398 * we've verified it with a MAC. That includes the packet
1399 * length, so we just read data and check the MAC repeatedly,
1400 * and when the MAC passes, see if the length we've got is
1404 /* May as well allocate the whole lot now. */
1405 st
->pktin
->data
= snewn(OUR_V2_PACKETLIMIT
+ st
->maclen
+ APIEXTRA
,
1408 /* Read an amount corresponding to the MAC. */
1409 for (st
->i
= 0; st
->i
< st
->maclen
; st
->i
++) {
1410 while ((*datalen
) == 0)
1412 st
->pktin
->data
[st
->i
] = *(*data
)++;
1418 unsigned char seq
[4];
1419 ssh
->scmac
->start(ssh
->sc_mac_ctx
);
1420 PUT_32BIT(seq
, st
->incoming_sequence
);
1421 ssh
->scmac
->bytes(ssh
->sc_mac_ctx
, seq
, 4);
1424 for (;;) { /* Once around this loop per cipher block. */
1425 /* Read another cipher-block's worth, and tack it onto the end. */
1426 for (st
->i
= 0; st
->i
< st
->cipherblk
; st
->i
++) {
1427 while ((*datalen
) == 0)
1429 st
->pktin
->data
[st
->packetlen
+st
->maclen
+st
->i
] = *(*data
)++;
1432 /* Decrypt one more block (a little further back in the stream). */
1433 ssh
->sccipher
->decrypt(ssh
->sc_cipher_ctx
,
1434 st
->pktin
->data
+ st
->packetlen
,
1436 /* Feed that block to the MAC. */
1437 ssh
->scmac
->bytes(ssh
->sc_mac_ctx
,
1438 st
->pktin
->data
+ st
->packetlen
, st
->cipherblk
);
1439 st
->packetlen
+= st
->cipherblk
;
1440 /* See if that gives us a valid packet. */
1441 if (ssh
->scmac
->verresult(ssh
->sc_mac_ctx
,
1442 st
->pktin
->data
+ st
->packetlen
) &&
1443 (st
->len
= GET_32BIT(st
->pktin
->data
)) + 4 == st
->packetlen
)
1445 if (st
->packetlen
>= OUR_V2_PACKETLIMIT
) {
1446 bombout(("No valid incoming packet found"));
1447 ssh_free_packet(st
->pktin
);
1451 st
->pktin
->maxlen
= st
->packetlen
+ st
->maclen
;
1452 st
->pktin
->data
= sresize(st
->pktin
->data
,
1453 st
->pktin
->maxlen
+ APIEXTRA
,
1456 st
->pktin
->data
= snewn(st
->cipherblk
+ APIEXTRA
, unsigned char);
1459 * Acquire and decrypt the first block of the packet. This will
1460 * contain the length and padding details.
1462 for (st
->i
= st
->len
= 0; st
->i
< st
->cipherblk
; st
->i
++) {
1463 while ((*datalen
) == 0)
1465 st
->pktin
->data
[st
->i
] = *(*data
)++;
1470 ssh
->sccipher
->decrypt(ssh
->sc_cipher_ctx
,
1471 st
->pktin
->data
, st
->cipherblk
);
1474 * Now get the length figure.
1476 st
->len
= GET_32BIT(st
->pktin
->data
);
1479 * _Completely_ silly lengths should be stomped on before they
1480 * do us any more damage.
1482 if (st
->len
< 0 || st
->len
> OUR_V2_PACKETLIMIT
||
1483 (st
->len
+ 4) % st
->cipherblk
!= 0) {
1484 bombout(("Incoming packet was garbled on decryption"));
1485 ssh_free_packet(st
->pktin
);
1490 * So now we can work out the total packet length.
1492 st
->packetlen
= st
->len
+ 4;
1495 * Allocate memory for the rest of the packet.
1497 st
->pktin
->maxlen
= st
->packetlen
+ st
->maclen
;
1498 st
->pktin
->data
= sresize(st
->pktin
->data
,
1499 st
->pktin
->maxlen
+ APIEXTRA
,
1503 * Read and decrypt the remainder of the packet.
1505 for (st
->i
= st
->cipherblk
; st
->i
< st
->packetlen
+ st
->maclen
;
1507 while ((*datalen
) == 0)
1509 st
->pktin
->data
[st
->i
] = *(*data
)++;
1512 /* Decrypt everything _except_ the MAC. */
1514 ssh
->sccipher
->decrypt(ssh
->sc_cipher_ctx
,
1515 st
->pktin
->data
+ st
->cipherblk
,
1516 st
->packetlen
- st
->cipherblk
);
1522 && !ssh
->scmac
->verify(ssh
->sc_mac_ctx
, st
->pktin
->data
,
1523 st
->len
+ 4, st
->incoming_sequence
)) {
1524 bombout(("Incorrect MAC received on packet"));
1525 ssh_free_packet(st
->pktin
);
1529 /* Get and sanity-check the amount of random padding. */
1530 st
->pad
= st
->pktin
->data
[4];
1531 if (st
->pad
< 4 || st
->len
- st
->pad
< 1) {
1532 bombout(("Invalid padding length on received packet"));
1533 ssh_free_packet(st
->pktin
);
1537 * This enables us to deduce the payload length.
1539 st
->payload
= st
->len
- st
->pad
- 1;
1541 st
->pktin
->length
= st
->payload
+ 5;
1542 st
->pktin
->encrypted_len
= st
->packetlen
;
1544 st
->pktin
->sequence
= st
->incoming_sequence
++;
1547 * Decompress packet payload.
1550 unsigned char *newpayload
;
1553 ssh
->sccomp
->decompress(ssh
->sc_comp_ctx
,
1554 st
->pktin
->data
+ 5, st
->pktin
->length
- 5,
1555 &newpayload
, &newlen
)) {
1556 if (st
->pktin
->maxlen
< newlen
+ 5) {
1557 st
->pktin
->maxlen
= newlen
+ 5;
1558 st
->pktin
->data
= sresize(st
->pktin
->data
,
1559 st
->pktin
->maxlen
+ APIEXTRA
,
1562 st
->pktin
->length
= 5 + newlen
;
1563 memcpy(st
->pktin
->data
+ 5, newpayload
, newlen
);
1568 st
->pktin
->savedpos
= 6;
1569 st
->pktin
->body
= st
->pktin
->data
;
1570 st
->pktin
->type
= st
->pktin
->data
[5];
1573 * Log incoming packet, possibly omitting sensitive fields.
1577 struct logblank_t blank
;
1578 if (ssh
->logomitdata
) {
1579 int do_blank
= FALSE
, blank_prefix
= 0;
1580 /* "Session data" packets - omit the data field */
1581 if (st
->pktin
->type
== SSH2_MSG_CHANNEL_DATA
) {
1582 do_blank
= TRUE
; blank_prefix
= 8;
1583 } else if (st
->pktin
->type
== SSH2_MSG_CHANNEL_EXTENDED_DATA
) {
1584 do_blank
= TRUE
; blank_prefix
= 12;
1587 blank
.offset
= blank_prefix
;
1588 blank
.len
= (st
->pktin
->length
-6) - blank_prefix
;
1589 blank
.type
= PKTLOG_OMIT
;
1593 log_packet(ssh
->logctx
, PKT_INCOMING
, st
->pktin
->type
,
1594 ssh2_pkt_type(ssh
->pkt_kctx
, ssh
->pkt_actx
,
1596 st
->pktin
->data
+6, st
->pktin
->length
-6,
1597 nblanks
, &blank
, &st
->pktin
->sequence
);
1600 crFinish(st
->pktin
);
1603 static int s_wrpkt_prepare(Ssh ssh
, struct Packet
*pkt
, int *offset_p
)
1605 int pad
, biglen
, i
, pktoffs
;
1609 * XXX various versions of SC (including 8.8.4) screw up the
1610 * register allocation in this function and use the same register
1611 * (D6) for len and as a temporary, with predictable results. The
1612 * following sledgehammer prevents this.
1619 log_packet(ssh
->logctx
, PKT_OUTGOING
, pkt
->data
[12],
1620 ssh1_pkt_type(pkt
->data
[12]),
1621 pkt
->body
, pkt
->length
- (pkt
->body
- pkt
->data
),
1622 pkt
->nblanks
, pkt
->blanks
, NULL
);
1623 sfree(pkt
->blanks
); pkt
->blanks
= NULL
;
1626 if (ssh
->v1_compressing
) {
1627 unsigned char *compblk
;
1629 zlib_compress_block(ssh
->cs_comp_ctx
,
1630 pkt
->data
+ 12, pkt
->length
- 12,
1631 &compblk
, &complen
);
1632 ssh_pkt_ensure(pkt
, complen
+ 2); /* just in case it's got bigger */
1633 memcpy(pkt
->data
+ 12, compblk
, complen
);
1635 pkt
->length
= complen
+ 12;
1638 ssh_pkt_ensure(pkt
, pkt
->length
+ 4); /* space for CRC */
1640 len
= pkt
->length
- 4 - 8; /* len(type+data+CRC) */
1641 pad
= 8 - (len
% 8);
1643 biglen
= len
+ pad
; /* len(padding+type+data+CRC) */
1645 for (i
= pktoffs
; i
< 4+8; i
++)
1646 pkt
->data
[i
] = random_byte();
1647 crc
= crc32_compute(pkt
->data
+ pktoffs
+ 4, biglen
- 4); /* all ex len */
1648 PUT_32BIT(pkt
->data
+ pktoffs
+ 4 + biglen
- 4, crc
);
1649 PUT_32BIT(pkt
->data
+ pktoffs
, len
);
1652 ssh
->cipher
->encrypt(ssh
->v1_cipher_ctx
,
1653 pkt
->data
+ pktoffs
+ 4, biglen
);
1655 if (offset_p
) *offset_p
= pktoffs
;
1656 return biglen
+ 4; /* len(length+padding+type+data+CRC) */
1659 static int s_write(Ssh ssh
, void *data
, int len
)
1662 log_packet(ssh
->logctx
, PKT_OUTGOING
, -1, NULL
, data
, len
,
1664 return sk_write(ssh
->s
, (char *)data
, len
);
1667 static void s_wrpkt(Ssh ssh
, struct Packet
*pkt
)
1669 int len
, backlog
, offset
;
1670 len
= s_wrpkt_prepare(ssh
, pkt
, &offset
);
1671 backlog
= s_write(ssh
, pkt
->data
+ offset
, len
);
1672 if (backlog
> SSH_MAX_BACKLOG
)
1673 ssh_throttle_all(ssh
, 1, backlog
);
1674 ssh_free_packet(pkt
);
1677 static void s_wrpkt_defer(Ssh ssh
, struct Packet
*pkt
)
1680 len
= s_wrpkt_prepare(ssh
, pkt
, &offset
);
1681 if (ssh
->deferred_len
+ len
> ssh
->deferred_size
) {
1682 ssh
->deferred_size
= ssh
->deferred_len
+ len
+ 128;
1683 ssh
->deferred_send_data
= sresize(ssh
->deferred_send_data
,
1687 memcpy(ssh
->deferred_send_data
+ ssh
->deferred_len
,
1688 pkt
->data
+ offset
, len
);
1689 ssh
->deferred_len
+= len
;
1690 ssh_free_packet(pkt
);
1694 * Construct a SSH-1 packet with the specified contents.
1695 * (This all-at-once interface used to be the only one, but now SSH-1
1696 * packets can also be constructed incrementally.)
1698 static struct Packet
*construct_packet(Ssh ssh
, int pkttype
, va_list ap
)
1704 pkt
= ssh1_pkt_init(pkttype
);
1706 while ((argtype
= va_arg(ap
, int)) != PKT_END
) {
1707 unsigned char *argp
, argchar
;
1709 unsigned long argint
;
1712 /* Actual fields in the packet */
1714 argint
= va_arg(ap
, int);
1715 ssh_pkt_adduint32(pkt
, argint
);
1718 argchar
= (unsigned char) va_arg(ap
, int);
1719 ssh_pkt_addbyte(pkt
, argchar
);
1722 argp
= va_arg(ap
, unsigned char *);
1723 arglen
= va_arg(ap
, int);
1724 ssh_pkt_adddata(pkt
, argp
, arglen
);
1727 sargp
= va_arg(ap
, char *);
1728 ssh_pkt_addstring(pkt
, sargp
);
1731 bn
= va_arg(ap
, Bignum
);
1732 ssh1_pkt_addmp(pkt
, bn
);
1734 /* Tokens for modifications to packet logging */
1736 dont_log_password(ssh
, pkt
, PKTLOG_BLANK
);
1739 dont_log_data(ssh
, pkt
, PKTLOG_OMIT
);
1742 end_log_omission(ssh
, pkt
);
1750 static void send_packet(Ssh ssh
, int pkttype
, ...)
1754 va_start(ap
, pkttype
);
1755 pkt
= construct_packet(ssh
, pkttype
, ap
);
1760 static void defer_packet(Ssh ssh
, int pkttype
, ...)
1764 va_start(ap
, pkttype
);
1765 pkt
= construct_packet(ssh
, pkttype
, ap
);
1767 s_wrpkt_defer(ssh
, pkt
);
1770 static int ssh_versioncmp(char *a
, char *b
)
1773 unsigned long av
, bv
;
1775 av
= strtoul(a
, &ae
, 10);
1776 bv
= strtoul(b
, &be
, 10);
1778 return (av
< bv ?
-1 : +1);
1783 av
= strtoul(ae
, &ae
, 10);
1784 bv
= strtoul(be
, &be
, 10);
1786 return (av
< bv ?
-1 : +1);
1791 * Utility routines for putting an SSH-protocol `string' and
1792 * `uint32' into a hash state.
1794 static void hash_string(const struct ssh_hash
*h
, void *s
, void *str
, int len
)
1796 unsigned char lenblk
[4];
1797 PUT_32BIT(lenblk
, len
);
1798 h
->bytes(s
, lenblk
, 4);
1799 h
->bytes(s
, str
, len
);
1802 static void hash_uint32(const struct ssh_hash
*h
, void *s
, unsigned i
)
1804 unsigned char intblk
[4];
1805 PUT_32BIT(intblk
, i
);
1806 h
->bytes(s
, intblk
, 4);
1810 * Packet construction functions. Mostly shared between SSH-1 and SSH-2.
1812 static void ssh_pkt_ensure(struct Packet
*pkt
, int length
)
1814 if (pkt
->maxlen
< length
) {
1815 unsigned char *body
= pkt
->body
;
1816 int offset
= body ? body
- pkt
->data
: 0;
1817 pkt
->maxlen
= length
+ 256;
1818 pkt
->data
= sresize(pkt
->data
, pkt
->maxlen
+ APIEXTRA
, unsigned char);
1819 if (body
) pkt
->body
= pkt
->data
+ offset
;
1822 static void ssh_pkt_adddata(struct Packet
*pkt
, void *data
, int len
)
1824 if (pkt
->logmode
!= PKTLOG_EMIT
) {
1826 pkt
->blanks
= sresize(pkt
->blanks
, pkt
->nblanks
, struct logblank_t
);
1828 pkt
->blanks
[pkt
->nblanks
-1].offset
= pkt
->length
-
1829 (pkt
->body
- pkt
->data
);
1830 pkt
->blanks
[pkt
->nblanks
-1].len
= len
;
1831 pkt
->blanks
[pkt
->nblanks
-1].type
= pkt
->logmode
;
1834 ssh_pkt_ensure(pkt
, pkt
->length
);
1835 memcpy(pkt
->data
+ pkt
->length
- len
, data
, len
);
1837 static void ssh_pkt_addbyte(struct Packet
*pkt
, unsigned char byte
)
1839 ssh_pkt_adddata(pkt
, &byte
, 1);
1841 static void ssh2_pkt_addbool(struct Packet
*pkt
, unsigned char value
)
1843 ssh_pkt_adddata(pkt
, &value
, 1);
1845 static void ssh_pkt_adduint32(struct Packet
*pkt
, unsigned long value
)
1848 PUT_32BIT(x
, value
);
1849 ssh_pkt_adddata(pkt
, x
, 4);
1851 static void ssh_pkt_addstring_start(struct Packet
*pkt
)
1853 ssh_pkt_adduint32(pkt
, 0);
1854 pkt
->savedpos
= pkt
->length
;
1856 static void ssh_pkt_addstring_str(struct Packet
*pkt
, char *data
)
1858 ssh_pkt_adddata(pkt
, data
, strlen(data
));
1859 PUT_32BIT(pkt
->data
+ pkt
->savedpos
- 4, pkt
->length
- pkt
->savedpos
);
1861 static void ssh_pkt_addstring_data(struct Packet
*pkt
, char *data
, int len
)
1863 ssh_pkt_adddata(pkt
, data
, len
);
1864 PUT_32BIT(pkt
->data
+ pkt
->savedpos
- 4, pkt
->length
- pkt
->savedpos
);
1866 static void ssh_pkt_addstring(struct Packet
*pkt
, char *data
)
1868 ssh_pkt_addstring_start(pkt
);
1869 ssh_pkt_addstring_str(pkt
, data
);
1871 static void ssh1_pkt_addmp(struct Packet
*pkt
, Bignum b
)
1873 int len
= ssh1_bignum_length(b
);
1874 unsigned char *data
= snewn(len
, unsigned char);
1875 (void) ssh1_write_bignum(data
, b
);
1876 ssh_pkt_adddata(pkt
, data
, len
);
1879 static unsigned char *ssh2_mpint_fmt(Bignum b
, int *len
)
1882 int i
, n
= (bignum_bitcount(b
) + 7) / 8;
1883 p
= snewn(n
+ 1, unsigned char);
1885 for (i
= 1; i
<= n
; i
++)
1886 p
[i
] = bignum_byte(b
, n
- i
);
1888 while (i
<= n
&& p
[i
] == 0 && (p
[i
+ 1] & 0x80) == 0)
1890 memmove(p
, p
+ i
, n
+ 1 - i
);
1894 static void ssh2_pkt_addmp(struct Packet
*pkt
, Bignum b
)
1898 p
= ssh2_mpint_fmt(b
, &len
);
1899 ssh_pkt_addstring_start(pkt
);
1900 ssh_pkt_addstring_data(pkt
, (char *)p
, len
);
1904 static struct Packet
*ssh1_pkt_init(int pkt_type
)
1906 struct Packet
*pkt
= ssh_new_packet();
1907 pkt
->length
= 4 + 8; /* space for length + max padding */
1908 ssh_pkt_addbyte(pkt
, pkt_type
);
1909 pkt
->body
= pkt
->data
+ pkt
->length
;
1913 /* For legacy code (SSH-1 and -2 packet construction used to be separate) */
1914 #define ssh2_pkt_ensure(pkt, length) ssh_pkt_ensure(pkt, length)
1915 #define ssh2_pkt_adddata(pkt, data, len) ssh_pkt_adddata(pkt, data, len)
1916 #define ssh2_pkt_addbyte(pkt, byte) ssh_pkt_addbyte(pkt, byte)
1917 #define ssh2_pkt_adduint32(pkt, value) ssh_pkt_adduint32(pkt, value)
1918 #define ssh2_pkt_addstring_start(pkt) ssh_pkt_addstring_start(pkt)
1919 #define ssh2_pkt_addstring_str(pkt, data) ssh_pkt_addstring_str(pkt, data)
1920 #define ssh2_pkt_addstring_data(pkt, data, len) ssh_pkt_addstring_data(pkt, data, len)
1921 #define ssh2_pkt_addstring(pkt, data) ssh_pkt_addstring(pkt, data)
1923 static struct Packet
*ssh2_pkt_init(int pkt_type
)
1925 struct Packet
*pkt
= ssh_new_packet();
1926 pkt
->length
= 5; /* space for packet length + padding length */
1928 ssh_pkt_addbyte(pkt
, (unsigned char) pkt_type
);
1929 pkt
->body
= pkt
->data
+ pkt
->length
; /* after packet type */
1934 * Construct an SSH-2 final-form packet: compress it, encrypt it,
1935 * put the MAC on it. Final packet, ready to be sent, is stored in
1936 * pkt->data. Total length is returned.
1938 static int ssh2_pkt_construct(Ssh ssh
, struct Packet
*pkt
)
1940 int cipherblk
, maclen
, padding
, i
;
1943 log_packet(ssh
->logctx
, PKT_OUTGOING
, pkt
->data
[5],
1944 ssh2_pkt_type(ssh
->pkt_kctx
, ssh
->pkt_actx
, pkt
->data
[5]),
1945 pkt
->body
, pkt
->length
- (pkt
->body
- pkt
->data
),
1946 pkt
->nblanks
, pkt
->blanks
, &ssh
->v2_outgoing_sequence
);
1947 sfree(pkt
->blanks
); pkt
->blanks
= NULL
;
1951 * Compress packet payload.
1954 unsigned char *newpayload
;
1957 ssh
->cscomp
->compress(ssh
->cs_comp_ctx
, pkt
->data
+ 5,
1959 &newpayload
, &newlen
)) {
1961 ssh2_pkt_adddata(pkt
, newpayload
, newlen
);
1967 * Add padding. At least four bytes, and must also bring total
1968 * length (minus MAC) up to a multiple of the block size.
1969 * If pkt->forcepad is set, make sure the packet is at least that size
1972 cipherblk
= ssh
->cscipher ? ssh
->cscipher
->blksize
: 8; /* block size */
1973 cipherblk
= cipherblk
< 8 ?
8 : cipherblk
; /* or 8 if blksize < 8 */
1975 if (pkt
->length
+ padding
< pkt
->forcepad
)
1976 padding
= pkt
->forcepad
- pkt
->length
;
1978 (cipherblk
- (pkt
->length
+ padding
) % cipherblk
) % cipherblk
;
1979 assert(padding
<= 255);
1980 maclen
= ssh
->csmac ? ssh
->csmac
->len
: 0;
1981 ssh2_pkt_ensure(pkt
, pkt
->length
+ padding
+ maclen
);
1982 pkt
->data
[4] = padding
;
1983 for (i
= 0; i
< padding
; i
++)
1984 pkt
->data
[pkt
->length
+ i
] = random_byte();
1985 PUT_32BIT(pkt
->data
, pkt
->length
+ padding
- 4);
1987 ssh
->csmac
->generate(ssh
->cs_mac_ctx
, pkt
->data
,
1988 pkt
->length
+ padding
,
1989 ssh
->v2_outgoing_sequence
);
1990 ssh
->v2_outgoing_sequence
++; /* whether or not we MACed */
1993 ssh
->cscipher
->encrypt(ssh
->cs_cipher_ctx
,
1994 pkt
->data
, pkt
->length
+ padding
);
1996 pkt
->encrypted_len
= pkt
->length
+ padding
;
1998 /* Ready-to-send packet starts at pkt->data. We return length. */
1999 return pkt
->length
+ padding
+ maclen
;
2003 * Routines called from the main SSH code to send packets. There
2004 * are quite a few of these, because we have two separate
2005 * mechanisms for delaying the sending of packets:
2007 * - In order to send an IGNORE message and a password message in
2008 * a single fixed-length blob, we require the ability to
2009 * concatenate the encrypted forms of those two packets _into_ a
2010 * single blob and then pass it to our <network.h> transport
2011 * layer in one go. Hence, there's a deferment mechanism which
2012 * works after packet encryption.
2014 * - In order to avoid sending any connection-layer messages
2015 * during repeat key exchange, we have to queue up any such
2016 * outgoing messages _before_ they are encrypted (and in
2017 * particular before they're allocated sequence numbers), and
2018 * then send them once we've finished.
2020 * I call these mechanisms `defer' and `queue' respectively, so as
2021 * to distinguish them reasonably easily.
2023 * The functions send_noqueue() and defer_noqueue() free the packet
2024 * structure they are passed. Every outgoing packet goes through
2025 * precisely one of these functions in its life; packets passed to
2026 * ssh2_pkt_send() or ssh2_pkt_defer() either go straight to one of
2027 * these or get queued, and then when the queue is later emptied
2028 * the packets are all passed to defer_noqueue().
2030 * When using a CBC-mode cipher, it's necessary to ensure that an
2031 * attacker can't provide data to be encrypted using an IV that they
2032 * know. We ensure this by prefixing each packet that might contain
2033 * user data with an SSH_MSG_IGNORE. This is done using the deferral
2034 * mechanism, so in this case send_noqueue() ends up redirecting to
2035 * defer_noqueue(). If you don't like this inefficiency, don't use
2039 static void ssh2_pkt_defer_noqueue(Ssh
, struct Packet
*, int);
2040 static void ssh_pkt_defersend(Ssh
);
2043 * Send an SSH-2 packet immediately, without queuing or deferring.
2045 static void ssh2_pkt_send_noqueue(Ssh ssh
, struct Packet
*pkt
)
2049 if (ssh
->cscipher
!= NULL
&& (ssh
->cscipher
->flags
& SSH_CIPHER_IS_CBC
)) {
2050 /* We need to send two packets, so use the deferral mechanism. */
2051 ssh2_pkt_defer_noqueue(ssh
, pkt
, FALSE
);
2052 ssh_pkt_defersend(ssh
);
2055 len
= ssh2_pkt_construct(ssh
, pkt
);
2056 backlog
= s_write(ssh
, pkt
->data
, len
);
2057 if (backlog
> SSH_MAX_BACKLOG
)
2058 ssh_throttle_all(ssh
, 1, backlog
);
2060 ssh
->outgoing_data_size
+= pkt
->encrypted_len
;
2061 if (!ssh
->kex_in_progress
&&
2062 ssh
->max_data_size
!= 0 &&
2063 ssh
->outgoing_data_size
> ssh
->max_data_size
)
2064 do_ssh2_transport(ssh
, "too much data sent", -1, NULL
);
2066 ssh_free_packet(pkt
);
2070 * Defer an SSH-2 packet.
2072 static void ssh2_pkt_defer_noqueue(Ssh ssh
, struct Packet
*pkt
, int noignore
)
2075 if (ssh
->cscipher
!= NULL
&& (ssh
->cscipher
->flags
& SSH_CIPHER_IS_CBC
) &&
2076 ssh
->deferred_len
== 0 && !noignore
&&
2077 !(ssh
->remote_bugs
& BUG_CHOKES_ON_SSH2_IGNORE
)) {
2079 * Interpose an SSH_MSG_IGNORE to ensure that user data don't
2080 * get encrypted with a known IV.
2082 struct Packet
*ipkt
= ssh2_pkt_init(SSH2_MSG_IGNORE
);
2083 ssh2_pkt_addstring_start(ipkt
);
2084 ssh2_pkt_defer_noqueue(ssh
, ipkt
, TRUE
);
2086 len
= ssh2_pkt_construct(ssh
, pkt
);
2087 if (ssh
->deferred_len
+ len
> ssh
->deferred_size
) {
2088 ssh
->deferred_size
= ssh
->deferred_len
+ len
+ 128;
2089 ssh
->deferred_send_data
= sresize(ssh
->deferred_send_data
,
2093 memcpy(ssh
->deferred_send_data
+ ssh
->deferred_len
, pkt
->data
, len
);
2094 ssh
->deferred_len
+= len
;
2095 ssh
->deferred_data_size
+= pkt
->encrypted_len
;
2096 ssh_free_packet(pkt
);
2100 * Queue an SSH-2 packet.
2102 static void ssh2_pkt_queue(Ssh ssh
, struct Packet
*pkt
)
2104 assert(ssh
->queueing
);
2106 if (ssh
->queuelen
>= ssh
->queuesize
) {
2107 ssh
->queuesize
= ssh
->queuelen
+ 32;
2108 ssh
->queue
= sresize(ssh
->queue
, ssh
->queuesize
, struct Packet
*);
2111 ssh
->queue
[ssh
->queuelen
++] = pkt
;
2115 * Either queue or send a packet, depending on whether queueing is
2118 static void ssh2_pkt_send(Ssh ssh
, struct Packet
*pkt
)
2121 ssh2_pkt_queue(ssh
, pkt
);
2123 ssh2_pkt_send_noqueue(ssh
, pkt
);
2127 * Either queue or defer a packet, depending on whether queueing is
2130 static void ssh2_pkt_defer(Ssh ssh
, struct Packet
*pkt
)
2133 ssh2_pkt_queue(ssh
, pkt
);
2135 ssh2_pkt_defer_noqueue(ssh
, pkt
, FALSE
);
2139 * Send the whole deferred data block constructed by
2140 * ssh2_pkt_defer() or SSH-1's defer_packet().
2142 * The expected use of the defer mechanism is that you call
2143 * ssh2_pkt_defer() a few times, then call ssh_pkt_defersend(). If
2144 * not currently queueing, this simply sets up deferred_send_data
2145 * and then sends it. If we _are_ currently queueing, the calls to
2146 * ssh2_pkt_defer() put the deferred packets on to the queue
2147 * instead, and therefore ssh_pkt_defersend() has no deferred data
2148 * to send. Hence, there's no need to make it conditional on
2151 static void ssh_pkt_defersend(Ssh ssh
)
2154 backlog
= s_write(ssh
, ssh
->deferred_send_data
, ssh
->deferred_len
);
2155 ssh
->deferred_len
= ssh
->deferred_size
= 0;
2156 sfree(ssh
->deferred_send_data
);
2157 ssh
->deferred_send_data
= NULL
;
2158 if (backlog
> SSH_MAX_BACKLOG
)
2159 ssh_throttle_all(ssh
, 1, backlog
);
2161 ssh
->outgoing_data_size
+= ssh
->deferred_data_size
;
2162 if (!ssh
->kex_in_progress
&&
2163 ssh
->max_data_size
!= 0 &&
2164 ssh
->outgoing_data_size
> ssh
->max_data_size
)
2165 do_ssh2_transport(ssh
, "too much data sent", -1, NULL
);
2166 ssh
->deferred_data_size
= 0;
2170 * Send a packet whose length needs to be disguised (typically
2171 * passwords or keyboard-interactive responses).
2173 static void ssh2_pkt_send_with_padding(Ssh ssh
, struct Packet
*pkt
,
2179 * The simplest way to do this is to adjust the
2180 * variable-length padding field in the outgoing packet.
2182 * Currently compiled out, because some Cisco SSH servers
2183 * don't like excessively padded packets (bah, why's it
2186 pkt
->forcepad
= padsize
;
2187 ssh2_pkt_send(ssh
, pkt
);
2192 * If we can't do that, however, an alternative approach is
2193 * to use the pkt_defer mechanism to bundle the packet
2194 * tightly together with an SSH_MSG_IGNORE such that their
2195 * combined length is a constant. So first we construct the
2196 * final form of this packet and defer its sending.
2198 ssh2_pkt_defer(ssh
, pkt
);
2201 * Now construct an SSH_MSG_IGNORE which includes a string
2202 * that's an exact multiple of the cipher block size. (If
2203 * the cipher is NULL so that the block size is
2204 * unavailable, we don't do this trick at all, because we
2205 * gain nothing by it.)
2207 if (ssh
->cscipher
&&
2208 !(ssh
->remote_bugs
& BUG_CHOKES_ON_SSH2_IGNORE
)) {
2211 stringlen
= (256 - ssh
->deferred_len
);
2212 stringlen
+= ssh
->cscipher
->blksize
- 1;
2213 stringlen
-= (stringlen
% ssh
->cscipher
->blksize
);
2216 * Temporarily disable actual compression, so we
2217 * can guarantee to get this string exactly the
2218 * length we want it. The compression-disabling
2219 * routine should return an integer indicating how
2220 * many bytes we should adjust our string length
2224 ssh
->cscomp
->disable_compression(ssh
->cs_comp_ctx
);
2226 pkt
= ssh2_pkt_init(SSH2_MSG_IGNORE
);
2227 ssh2_pkt_addstring_start(pkt
);
2228 for (i
= 0; i
< stringlen
; i
++) {
2229 char c
= (char) random_byte();
2230 ssh2_pkt_addstring_data(pkt
, &c
, 1);
2232 ssh2_pkt_defer(ssh
, pkt
);
2234 ssh_pkt_defersend(ssh
);
2239 * Send all queued SSH-2 packets. We send them by means of
2240 * ssh2_pkt_defer_noqueue(), in case they included a pair of
2241 * packets that needed to be lumped together.
2243 static void ssh2_pkt_queuesend(Ssh ssh
)
2247 assert(!ssh
->queueing
);
2249 for (i
= 0; i
< ssh
->queuelen
; i
++)
2250 ssh2_pkt_defer_noqueue(ssh
, ssh
->queue
[i
], FALSE
);
2253 ssh_pkt_defersend(ssh
);
2257 void bndebug(char *string
, Bignum b
)
2261 p
= ssh2_mpint_fmt(b
, &len
);
2262 debug(("%s", string
));
2263 for (i
= 0; i
< len
; i
++)
2264 debug((" %02x", p
[i
]));
2270 static void hash_mpint(const struct ssh_hash
*h
, void *s
, Bignum b
)
2274 p
= ssh2_mpint_fmt(b
, &len
);
2275 hash_string(h
, s
, p
, len
);
2280 * Packet decode functions for both SSH-1 and SSH-2.
2282 static unsigned long ssh_pkt_getuint32(struct Packet
*pkt
)
2284 unsigned long value
;
2285 if (pkt
->length
- pkt
->savedpos
< 4)
2286 return 0; /* arrgh, no way to decline (FIXME?) */
2287 value
= GET_32BIT(pkt
->body
+ pkt
->savedpos
);
2291 static int ssh2_pkt_getbool(struct Packet
*pkt
)
2293 unsigned long value
;
2294 if (pkt
->length
- pkt
->savedpos
< 1)
2295 return 0; /* arrgh, no way to decline (FIXME?) */
2296 value
= pkt
->body
[pkt
->savedpos
] != 0;
2300 static void ssh_pkt_getstring(struct Packet
*pkt
, char **p
, int *length
)
2305 if (pkt
->length
- pkt
->savedpos
< 4)
2307 len
= GET_32BIT(pkt
->body
+ pkt
->savedpos
);
2312 if (pkt
->length
- pkt
->savedpos
< *length
)
2314 *p
= (char *)(pkt
->body
+ pkt
->savedpos
);
2315 pkt
->savedpos
+= *length
;
2317 static void *ssh_pkt_getdata(struct Packet
*pkt
, int length
)
2319 if (pkt
->length
- pkt
->savedpos
< length
)
2321 pkt
->savedpos
+= length
;
2322 return pkt
->body
+ (pkt
->savedpos
- length
);
2324 static int ssh1_pkt_getrsakey(struct Packet
*pkt
, struct RSAKey
*key
,
2325 unsigned char **keystr
)
2329 j
= makekey(pkt
->body
+ pkt
->savedpos
,
2330 pkt
->length
- pkt
->savedpos
,
2337 assert(pkt
->savedpos
< pkt
->length
);
2341 static Bignum
ssh1_pkt_getmp(struct Packet
*pkt
)
2346 j
= ssh1_read_bignum(pkt
->body
+ pkt
->savedpos
,
2347 pkt
->length
- pkt
->savedpos
, &b
);
2355 static Bignum
ssh2_pkt_getmp(struct Packet
*pkt
)
2361 ssh_pkt_getstring(pkt
, &p
, &length
);
2366 b
= bignum_from_bytes((unsigned char *)p
, length
);
2371 * Helper function to add an SSH-2 signature blob to a packet.
2372 * Expects to be shown the public key blob as well as the signature
2373 * blob. Normally works just like ssh2_pkt_addstring, but will
2374 * fiddle with the signature packet if necessary for
2375 * BUG_SSH2_RSA_PADDING.
2377 static void ssh2_add_sigblob(Ssh ssh
, struct Packet
*pkt
,
2378 void *pkblob_v
, int pkblob_len
,
2379 void *sigblob_v
, int sigblob_len
)
2381 unsigned char *pkblob
= (unsigned char *)pkblob_v
;
2382 unsigned char *sigblob
= (unsigned char *)sigblob_v
;
2384 /* dmemdump(pkblob, pkblob_len); */
2385 /* dmemdump(sigblob, sigblob_len); */
2388 * See if this is in fact an ssh-rsa signature and a buggy
2389 * server; otherwise we can just do this the easy way.
2391 if ((ssh
->remote_bugs
& BUG_SSH2_RSA_PADDING
) &&
2392 (GET_32BIT(pkblob
) == 7 && !memcmp(pkblob
+4, "ssh-rsa", 7))) {
2393 int pos
, len
, siglen
;
2396 * Find the byte length of the modulus.
2399 pos
= 4+7; /* skip over "ssh-rsa" */
2400 pos
+= 4 + GET_32BIT(pkblob
+pos
); /* skip over exponent */
2401 len
= GET_32BIT(pkblob
+pos
); /* find length of modulus */
2402 pos
+= 4; /* find modulus itself */
2403 while (len
> 0 && pkblob
[pos
] == 0)
2405 /* debug(("modulus length is %d\n", len)); */
2408 * Now find the signature integer.
2410 pos
= 4+7; /* skip over "ssh-rsa" */
2411 siglen
= GET_32BIT(sigblob
+pos
);
2412 /* debug(("signature length is %d\n", siglen)); */
2414 if (len
!= siglen
) {
2415 unsigned char newlen
[4];
2416 ssh2_pkt_addstring_start(pkt
);
2417 ssh2_pkt_addstring_data(pkt
, (char *)sigblob
, pos
);
2418 /* dmemdump(sigblob, pos); */
2419 pos
+= 4; /* point to start of actual sig */
2420 PUT_32BIT(newlen
, len
);
2421 ssh2_pkt_addstring_data(pkt
, (char *)newlen
, 4);
2422 /* dmemdump(newlen, 4); */
2424 while (len
-- > siglen
) {
2425 ssh2_pkt_addstring_data(pkt
, (char *)newlen
, 1);
2426 /* dmemdump(newlen, 1); */
2428 ssh2_pkt_addstring_data(pkt
, (char *)(sigblob
+pos
), siglen
);
2429 /* dmemdump(sigblob+pos, siglen); */
2433 /* Otherwise fall through and do it the easy way. */
2436 ssh2_pkt_addstring_start(pkt
);
2437 ssh2_pkt_addstring_data(pkt
, (char *)sigblob
, sigblob_len
);
2441 * Examine the remote side's version string and compare it against
2442 * a list of known buggy implementations.
2444 static void ssh_detect_bugs(Ssh ssh
, char *vstring
)
2446 char *imp
; /* pointer to implementation part */
2448 imp
+= strcspn(imp
, "-");
2450 imp
+= strcspn(imp
, "-");
2453 ssh
->remote_bugs
= 0;
2456 * General notes on server version strings:
2457 * - Not all servers reporting "Cisco-1.25" have all the bugs listed
2458 * here -- in particular, we've heard of one that's perfectly happy
2459 * with SSH1_MSG_IGNOREs -- but this string never seems to change,
2460 * so we can't distinguish them.
2462 if (conf_get_int(ssh
->conf
, CONF_sshbug_ignore1
) == FORCE_ON
||
2463 (conf_get_int(ssh
->conf
, CONF_sshbug_ignore1
) == AUTO
&&
2464 (!strcmp(imp
, "1.2.18") || !strcmp(imp
, "1.2.19") ||
2465 !strcmp(imp
, "1.2.20") || !strcmp(imp
, "1.2.21") ||
2466 !strcmp(imp
, "1.2.22") || !strcmp(imp
, "Cisco-1.25") ||
2467 !strcmp(imp
, "OSU_1.4alpha3") || !strcmp(imp
, "OSU_1.5alpha4")))) {
2469 * These versions don't support SSH1_MSG_IGNORE, so we have
2470 * to use a different defence against password length
2473 ssh
->remote_bugs
|= BUG_CHOKES_ON_SSH1_IGNORE
;
2474 logevent("We believe remote version has SSH-1 ignore bug");
2477 if (conf_get_int(ssh
->conf
, CONF_sshbug_plainpw1
) == FORCE_ON
||
2478 (conf_get_int(ssh
->conf
, CONF_sshbug_plainpw1
) == AUTO
&&
2479 (!strcmp(imp
, "Cisco-1.25") || !strcmp(imp
, "OSU_1.4alpha3")))) {
2481 * These versions need a plain password sent; they can't
2482 * handle having a null and a random length of data after
2485 ssh
->remote_bugs
|= BUG_NEEDS_SSH1_PLAIN_PASSWORD
;
2486 logevent("We believe remote version needs a plain SSH-1 password");
2489 if (conf_get_int(ssh
->conf
, CONF_sshbug_rsa1
) == FORCE_ON
||
2490 (conf_get_int(ssh
->conf
, CONF_sshbug_rsa1
) == AUTO
&&
2491 (!strcmp(imp
, "Cisco-1.25")))) {
2493 * These versions apparently have no clue whatever about
2494 * RSA authentication and will panic and die if they see
2495 * an AUTH_RSA message.
2497 ssh
->remote_bugs
|= BUG_CHOKES_ON_RSA
;
2498 logevent("We believe remote version can't handle SSH-1 RSA authentication");
2501 if (conf_get_int(ssh
->conf
, CONF_sshbug_hmac2
) == FORCE_ON
||
2502 (conf_get_int(ssh
->conf
, CONF_sshbug_hmac2
) == AUTO
&&
2503 !wc_match("* VShell", imp
) &&
2504 (wc_match("2.1.0*", imp
) || wc_match("2.0.*", imp
) ||
2505 wc_match("2.2.0*", imp
) || wc_match("2.3.0*", imp
) ||
2506 wc_match("2.1 *", imp
)))) {
2508 * These versions have the HMAC bug.
2510 ssh
->remote_bugs
|= BUG_SSH2_HMAC
;
2511 logevent("We believe remote version has SSH-2 HMAC bug");
2514 if (conf_get_int(ssh
->conf
, CONF_sshbug_derivekey2
) == FORCE_ON
||
2515 (conf_get_int(ssh
->conf
, CONF_sshbug_derivekey2
) == AUTO
&&
2516 !wc_match("* VShell", imp
) &&
2517 (wc_match("2.0.0*", imp
) || wc_match("2.0.10*", imp
) ))) {
2519 * These versions have the key-derivation bug (failing to
2520 * include the literal shared secret in the hashes that
2521 * generate the keys).
2523 ssh
->remote_bugs
|= BUG_SSH2_DERIVEKEY
;
2524 logevent("We believe remote version has SSH-2 key-derivation bug");
2527 if (conf_get_int(ssh
->conf
, CONF_sshbug_rsapad2
) == FORCE_ON
||
2528 (conf_get_int(ssh
->conf
, CONF_sshbug_rsapad2
) == AUTO
&&
2529 (wc_match("OpenSSH_2.[5-9]*", imp
) ||
2530 wc_match("OpenSSH_3.[0-2]*", imp
)))) {
2532 * These versions have the SSH-2 RSA padding bug.
2534 ssh
->remote_bugs
|= BUG_SSH2_RSA_PADDING
;
2535 logevent("We believe remote version has SSH-2 RSA padding bug");
2538 if (conf_get_int(ssh
->conf
, CONF_sshbug_pksessid2
) == FORCE_ON
||
2539 (conf_get_int(ssh
->conf
, CONF_sshbug_pksessid2
) == AUTO
&&
2540 wc_match("OpenSSH_2.[0-2]*", imp
))) {
2542 * These versions have the SSH-2 session-ID bug in
2543 * public-key authentication.
2545 ssh
->remote_bugs
|= BUG_SSH2_PK_SESSIONID
;
2546 logevent("We believe remote version has SSH-2 public-key-session-ID bug");
2549 if (conf_get_int(ssh
->conf
, CONF_sshbug_rekey2
) == FORCE_ON
||
2550 (conf_get_int(ssh
->conf
, CONF_sshbug_rekey2
) == AUTO
&&
2551 (wc_match("DigiSSH_2.0", imp
) ||
2552 wc_match("OpenSSH_2.[0-4]*", imp
) ||
2553 wc_match("OpenSSH_2.5.[0-3]*", imp
) ||
2554 wc_match("Sun_SSH_1.0", imp
) ||
2555 wc_match("Sun_SSH_1.0.1", imp
) ||
2556 /* All versions <= 1.2.6 (they changed their format in 1.2.7) */
2557 wc_match("WeOnlyDo-*", imp
)))) {
2559 * These versions have the SSH-2 rekey bug.
2561 ssh
->remote_bugs
|= BUG_SSH2_REKEY
;
2562 logevent("We believe remote version has SSH-2 rekey bug");
2565 if (conf_get_int(ssh
->conf
, CONF_sshbug_maxpkt2
) == FORCE_ON
||
2566 (conf_get_int(ssh
->conf
, CONF_sshbug_maxpkt2
) == AUTO
&&
2567 (wc_match("1.36_sshlib GlobalSCAPE", imp
) ||
2568 wc_match("1.36 sshlib: GlobalScape", imp
)))) {
2570 * This version ignores our makpkt and needs to be throttled.
2572 ssh
->remote_bugs
|= BUG_SSH2_MAXPKT
;
2573 logevent("We believe remote version ignores SSH-2 maximum packet size");
2576 if (conf_get_int(ssh
->conf
, CONF_sshbug_ignore2
) == FORCE_ON
) {
2578 * Servers that don't support SSH2_MSG_IGNORE. Currently,
2579 * none detected automatically.
2581 ssh
->remote_bugs
|= BUG_CHOKES_ON_SSH2_IGNORE
;
2582 logevent("We believe remote version has SSH-2 ignore bug");
2585 if (conf_get_int(ssh
->conf
, CONF_sshbug_winadj
) == FORCE_ON
) {
2587 * Servers that don't support our winadj request for one
2588 * reason or another. Currently, none detected automatically.
2590 ssh
->remote_bugs
|= BUG_CHOKES_ON_WINADJ
;
2591 logevent("We believe remote version has winadj bug");
2596 * The `software version' part of an SSH version string is required
2597 * to contain no spaces or minus signs.
2599 static void ssh_fix_verstring(char *str
)
2601 /* Eat "SSH-<protoversion>-". */
2602 assert(*str
== 'S'); str
++;
2603 assert(*str
== 'S'); str
++;
2604 assert(*str
== 'H'); str
++;
2605 assert(*str
== '-'); str
++;
2606 while (*str
&& *str
!= '-') str
++;
2607 assert(*str
== '-'); str
++;
2609 /* Convert minus signs and spaces in the remaining string into
2612 if (*str
== '-' || *str
== ' ')
2619 * Send an appropriate SSH version string.
2621 static void ssh_send_verstring(Ssh ssh
, char *svers
)
2625 if (ssh
->version
== 2) {
2627 * Construct a v2 version string.
2629 verstring
= dupprintf("SSH-2.0-%s\015\012", sshver
);
2632 * Construct a v1 version string.
2634 verstring
= dupprintf("SSH-%s-%s\012",
2635 (ssh_versioncmp(svers
, "1.5") <= 0 ?
2640 ssh_fix_verstring(verstring
);
2642 if (ssh
->version
== 2) {
2645 * Record our version string.
2647 len
= strcspn(verstring
, "\015\012");
2648 ssh
->v_c
= snewn(len
+ 1, char);
2649 memcpy(ssh
->v_c
, verstring
, len
);
2653 logeventf(ssh
, "We claim version: %.*s",
2654 strcspn(verstring
, "\015\012"), verstring
);
2655 s_write(ssh
, verstring
, strlen(verstring
));
2659 static int do_ssh_init(Ssh ssh
, unsigned char c
)
2661 struct do_ssh_init_state
{
2669 crState(do_ssh_init_state
);
2671 crBegin(ssh
->do_ssh_init_crstate
);
2673 /* Search for a line beginning with the string "SSH-" in the input. */
2675 if (c
!= 'S') goto no
;
2677 if (c
!= 'S') goto no
;
2679 if (c
!= 'H') goto no
;
2681 if (c
!= '-') goto no
;
2690 s
->vstring
= snewn(s
->vstrsize
, char);
2691 strcpy(s
->vstring
, "SSH-");
2695 crReturn(1); /* get another char */
2696 if (s
->vslen
>= s
->vstrsize
- 1) {
2698 s
->vstring
= sresize(s
->vstring
, s
->vstrsize
, char);
2700 s
->vstring
[s
->vslen
++] = c
;
2703 s
->version
[s
->i
] = '\0';
2705 } else if (s
->i
< sizeof(s
->version
) - 1)
2706 s
->version
[s
->i
++] = c
;
2707 } else if (c
== '\012')
2711 ssh
->agentfwd_enabled
= FALSE
;
2712 ssh
->rdpkt2_state
.incoming_sequence
= 0;
2714 s
->vstring
[s
->vslen
] = 0;
2715 s
->vstring
[strcspn(s
->vstring
, "\015\012")] = '\0';/* remove EOL chars */
2716 logeventf(ssh
, "Server version: %s", s
->vstring
);
2717 ssh_detect_bugs(ssh
, s
->vstring
);
2720 * Decide which SSH protocol version to support.
2723 /* Anything strictly below "2.0" means protocol 1 is supported. */
2724 s
->proto1
= ssh_versioncmp(s
->version
, "2.0") < 0;
2725 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
2726 s
->proto2
= ssh_versioncmp(s
->version
, "1.99") >= 0;
2728 if (conf_get_int(ssh
->conf
, CONF_sshprot
) == 0 && !s
->proto1
) {
2729 bombout(("SSH protocol version 1 required by user but not provided by server"));
2732 if (conf_get_int(ssh
->conf
, CONF_sshprot
) == 3 && !s
->proto2
) {
2733 bombout(("SSH protocol version 2 required by user but not provided by server"));
2737 if (s
->proto2
&& (conf_get_int(ssh
->conf
, CONF_sshprot
) >= 2 || !s
->proto1
))
2742 logeventf(ssh
, "Using SSH protocol version %d", ssh
->version
);
2744 /* Send the version string, if we haven't already */
2745 if (conf_get_int(ssh
->conf
, CONF_sshprot
) != 3)
2746 ssh_send_verstring(ssh
, s
->version
);
2748 if (ssh
->version
== 2) {
2751 * Record their version string.
2753 len
= strcspn(s
->vstring
, "\015\012");
2754 ssh
->v_s
= snewn(len
+ 1, char);
2755 memcpy(ssh
->v_s
, s
->vstring
, len
);
2759 * Initialise SSH-2 protocol.
2761 ssh
->protocol
= ssh2_protocol
;
2762 ssh2_protocol_setup(ssh
);
2763 ssh
->s_rdpkt
= ssh2_rdpkt
;
2766 * Initialise SSH-1 protocol.
2768 ssh
->protocol
= ssh1_protocol
;
2769 ssh1_protocol_setup(ssh
);
2770 ssh
->s_rdpkt
= ssh1_rdpkt
;
2772 if (ssh
->version
== 2)
2773 do_ssh2_transport(ssh
, NULL
, -1, NULL
);
2775 update_specials_menu(ssh
->frontend
);
2776 ssh
->state
= SSH_STATE_BEFORE_SIZE
;
2777 ssh
->pinger
= pinger_new(ssh
->conf
, &ssh_backend
, ssh
);
2784 static void ssh_process_incoming_data(Ssh ssh
,
2785 unsigned char **data
, int *datalen
)
2787 struct Packet
*pktin
;
2789 pktin
= ssh
->s_rdpkt(ssh
, data
, datalen
);
2791 ssh
->protocol(ssh
, NULL
, 0, pktin
);
2792 ssh_free_packet(pktin
);
2796 static void ssh_queue_incoming_data(Ssh ssh
,
2797 unsigned char **data
, int *datalen
)
2799 bufchain_add(&ssh
->queued_incoming_data
, *data
, *datalen
);
2804 static void ssh_process_queued_incoming_data(Ssh ssh
)
2807 unsigned char *data
;
2810 while (!ssh
->frozen
&& bufchain_size(&ssh
->queued_incoming_data
)) {
2811 bufchain_prefix(&ssh
->queued_incoming_data
, &vdata
, &len
);
2815 while (!ssh
->frozen
&& len
> 0)
2816 ssh_process_incoming_data(ssh
, &data
, &len
);
2819 bufchain_consume(&ssh
->queued_incoming_data
, origlen
- len
);
2823 static void ssh_set_frozen(Ssh ssh
, int frozen
)
2826 sk_set_frozen(ssh
->s
, frozen
);
2827 ssh
->frozen
= frozen
;
2830 static void ssh_gotdata(Ssh ssh
, unsigned char *data
, int datalen
)
2832 /* Log raw data, if we're in that mode. */
2834 log_packet(ssh
->logctx
, PKT_INCOMING
, -1, NULL
, data
, datalen
,
2837 crBegin(ssh
->ssh_gotdata_crstate
);
2840 * To begin with, feed the characters one by one to the
2841 * protocol initialisation / selection function do_ssh_init().
2842 * When that returns 0, we're done with the initial greeting
2843 * exchange and can move on to packet discipline.
2846 int ret
; /* need not be kept across crReturn */
2848 crReturnV
; /* more data please */
2849 ret
= do_ssh_init(ssh
, *data
);
2857 * We emerge from that loop when the initial negotiation is
2858 * over and we have selected an s_rdpkt function. Now pass
2859 * everything to s_rdpkt, and then pass the resulting packets
2860 * to the proper protocol handler.
2864 while (bufchain_size(&ssh
->queued_incoming_data
) > 0 || datalen
> 0) {
2866 ssh_queue_incoming_data(ssh
, &data
, &datalen
);
2867 /* This uses up all data and cannot cause anything interesting
2868 * to happen; indeed, for anything to happen at all, we must
2869 * return, so break out. */
2871 } else if (bufchain_size(&ssh
->queued_incoming_data
) > 0) {
2872 /* This uses up some or all data, and may freeze the
2874 ssh_process_queued_incoming_data(ssh
);
2876 /* This uses up some or all data, and may freeze the
2878 ssh_process_incoming_data(ssh
, &data
, &datalen
);
2880 /* FIXME this is probably EBW. */
2881 if (ssh
->state
== SSH_STATE_CLOSED
)
2884 /* We're out of data. Go and get some more. */
2890 static int ssh_do_close(Ssh ssh
, int notify_exit
)
2893 struct ssh_channel
*c
;
2895 ssh
->state
= SSH_STATE_CLOSED
;
2896 expire_timer_context(ssh
);
2901 notify_remote_exit(ssh
->frontend
);
2906 * Now we must shut down any port- and X-forwarded channels going
2907 * through this connection.
2909 if (ssh
->channels
) {
2910 while (NULL
!= (c
= index234(ssh
->channels
, 0))) {
2913 x11_close(c
->u
.x11
.s
);
2916 case CHAN_SOCKDATA_DORMANT
:
2917 pfd_close(c
->u
.pfd
.s
);
2920 del234(ssh
->channels
, c
); /* moving next one to index 0 */
2921 if (ssh
->version
== 2)
2922 bufchain_clear(&c
->v
.v2
.outbuffer
);
2927 * Go through port-forwardings, and close any associated
2928 * listening sockets.
2930 if (ssh
->portfwds
) {
2931 struct ssh_portfwd
*pf
;
2932 while (NULL
!= (pf
= index234(ssh
->portfwds
, 0))) {
2933 /* Dispose of any listening socket. */
2935 pfd_terminate(pf
->local
);
2936 del234(ssh
->portfwds
, pf
); /* moving next one to index 0 */
2939 freetree234(ssh
->portfwds
);
2940 ssh
->portfwds
= NULL
;
2946 static void ssh_log(Plug plug
, int type
, SockAddr addr
, int port
,
2947 const char *error_msg
, int error_code
)
2949 Ssh ssh
= (Ssh
) plug
;
2950 char addrbuf
[256], *msg
;
2952 sk_getaddr(addr
, addrbuf
, lenof(addrbuf
));
2955 msg
= dupprintf("Connecting to %s port %d", addrbuf
, port
);
2957 msg
= dupprintf("Failed to connect to %s: %s", addrbuf
, error_msg
);
2963 static int ssh_closing(Plug plug
, const char *error_msg
, int error_code
,
2966 Ssh ssh
= (Ssh
) plug
;
2967 int need_notify
= ssh_do_close(ssh
, FALSE
);
2970 if (!ssh
->close_expected
)
2971 error_msg
= "Server unexpectedly closed network connection";
2973 error_msg
= "Server closed network connection";
2976 if (ssh
->close_expected
&& ssh
->clean_exit
&& ssh
->exitcode
< 0)
2980 notify_remote_exit(ssh
->frontend
);
2983 logevent(error_msg
);
2984 if (!ssh
->close_expected
|| !ssh
->clean_exit
)
2985 connection_fatal(ssh
->frontend
, "%s", error_msg
);
2989 static int ssh_receive(Plug plug
, int urgent
, char *data
, int len
)
2991 Ssh ssh
= (Ssh
) plug
;
2992 ssh_gotdata(ssh
, (unsigned char *)data
, len
);
2993 if (ssh
->state
== SSH_STATE_CLOSED
) {
2994 ssh_do_close(ssh
, TRUE
);
3000 static void ssh_sent(Plug plug
, int bufsize
)
3002 Ssh ssh
= (Ssh
) plug
;
3004 * If the send backlog on the SSH socket itself clears, we
3005 * should unthrottle the whole world if it was throttled.
3007 if (bufsize
< SSH_MAX_BACKLOG
)
3008 ssh_throttle_all(ssh
, 0, bufsize
);
3012 * Connect to specified host and port.
3013 * Returns an error message, or NULL on success.
3014 * Also places the canonical host name into `realhost'. It must be
3015 * freed by the caller.
3017 static const char *connect_to_host(Ssh ssh
, char *host
, int port
,
3018 char **realhost
, int nodelay
, int keepalive
)
3020 static const struct plug_function_table fn_table
= {
3031 int addressfamily
, sshprot
;
3033 loghost
= conf_get_str(ssh
->conf
, CONF_loghost
);
3037 ssh
->savedhost
= dupstr(loghost
);
3038 ssh
->savedport
= 22; /* default ssh port */
3041 * A colon suffix on savedhost also lets us affect
3044 * (FIXME: do something about IPv6 address literals here.)
3046 colon
= strrchr(ssh
->savedhost
, ':');
3050 ssh
->savedport
= atoi(colon
);
3053 ssh
->savedhost
= dupstr(host
);
3055 port
= 22; /* default ssh port */
3056 ssh
->savedport
= port
;
3062 addressfamily
= conf_get_int(ssh
->conf
, CONF_addressfamily
);
3063 logeventf(ssh
, "Looking up host \"%s\"%s", host
,
3064 (addressfamily
== ADDRTYPE_IPV4 ?
" (IPv4)" :
3065 (addressfamily
== ADDRTYPE_IPV6 ?
" (IPv6)" : "")));
3066 addr
= name_lookup(host
, port
, realhost
, ssh
->conf
, addressfamily
);
3067 if ((err
= sk_addr_error(addr
)) != NULL
) {
3071 ssh
->fullhostname
= dupstr(*realhost
); /* save in case of GSSAPI */
3076 ssh
->fn
= &fn_table
;
3077 ssh
->s
= new_connection(addr
, *realhost
, port
,
3078 0, 1, nodelay
, keepalive
, (Plug
) ssh
, ssh
->conf
);
3079 if ((err
= sk_socket_error(ssh
->s
)) != NULL
) {
3081 notify_remote_exit(ssh
->frontend
);
3086 * If the SSH version number's fixed, set it now, and if it's SSH-2,
3087 * send the version string too.
3089 sshprot
= conf_get_int(ssh
->conf
, CONF_sshprot
);
3094 ssh_send_verstring(ssh
, NULL
);
3098 * loghost, if configured, overrides realhost.
3102 *realhost
= dupstr(loghost
);
3109 * Throttle or unthrottle the SSH connection.
3111 static void ssh_throttle_conn(Ssh ssh
, int adjust
)
3113 int old_count
= ssh
->conn_throttle_count
;
3114 ssh
->conn_throttle_count
+= adjust
;
3115 assert(ssh
->conn_throttle_count
>= 0);
3116 if (ssh
->conn_throttle_count
&& !old_count
) {
3117 ssh_set_frozen(ssh
, 1);
3118 } else if (!ssh
->conn_throttle_count
&& old_count
) {
3119 ssh_set_frozen(ssh
, 0);
3124 * Throttle or unthrottle _all_ local data streams (for when sends
3125 * on the SSH connection itself back up).
3127 static void ssh_throttle_all(Ssh ssh
, int enable
, int bufsize
)
3130 struct ssh_channel
*c
;
3132 if (enable
== ssh
->throttled_all
)
3134 ssh
->throttled_all
= enable
;
3135 ssh
->overall_bufsize
= bufsize
;
3138 for (i
= 0; NULL
!= (c
= index234(ssh
->channels
, i
)); i
++) {
3140 case CHAN_MAINSESSION
:
3142 * This is treated separately, outside the switch.
3146 x11_override_throttle(c
->u
.x11
.s
, enable
);
3149 /* Agent channels require no buffer management. */
3152 pfd_override_throttle(c
->u
.pfd
.s
, enable
);
3158 static void ssh_agent_callback(void *sshv
, void *reply
, int replylen
)
3160 Ssh ssh
= (Ssh
) sshv
;
3162 ssh
->agent_response
= reply
;
3163 ssh
->agent_response_len
= replylen
;
3165 if (ssh
->version
== 1)
3166 do_ssh1_login(ssh
, NULL
, -1, NULL
);
3168 do_ssh2_authconn(ssh
, NULL
, -1, NULL
);
3171 static void ssh_dialog_callback(void *sshv
, int ret
)
3173 Ssh ssh
= (Ssh
) sshv
;
3175 ssh
->user_response
= ret
;
3177 if (ssh
->version
== 1)
3178 do_ssh1_login(ssh
, NULL
, -1, NULL
);
3180 do_ssh2_transport(ssh
, NULL
, -1, NULL
);
3183 * This may have unfrozen the SSH connection, so do a
3186 ssh_process_queued_incoming_data(ssh
);
3189 static void ssh_agentf_callback(void *cv
, void *reply
, int replylen
)
3191 struct ssh_channel
*c
= (struct ssh_channel
*)cv
;
3193 void *sentreply
= reply
;
3196 /* Fake SSH_AGENT_FAILURE. */
3197 sentreply
= "\0\0\0\1\5";
3200 if (ssh
->version
== 2) {
3201 ssh2_add_channel_data(c
, sentreply
, replylen
);
3204 send_packet(ssh
, SSH1_MSG_CHANNEL_DATA
,
3205 PKT_INT
, c
->remoteid
,
3208 PKT_DATA
, sentreply
, replylen
,
3217 * Client-initiated disconnection. Send a DISCONNECT if `wire_reason'
3218 * non-NULL, otherwise just close the connection. `client_reason' == NULL
3219 * => log `wire_reason'.
3221 static void ssh_disconnect(Ssh ssh
, char *client_reason
, char *wire_reason
,
3222 int code
, int clean_exit
)
3226 client_reason
= wire_reason
;
3228 error
= dupprintf("Disconnected: %s", client_reason
);
3230 error
= dupstr("Disconnected");
3232 if (ssh
->version
== 1) {
3233 send_packet(ssh
, SSH1_MSG_DISCONNECT
, PKT_STR
, wire_reason
,
3235 } else if (ssh
->version
== 2) {
3236 struct Packet
*pktout
= ssh2_pkt_init(SSH2_MSG_DISCONNECT
);
3237 ssh2_pkt_adduint32(pktout
, code
);
3238 ssh2_pkt_addstring(pktout
, wire_reason
);
3239 ssh2_pkt_addstring(pktout
, "en"); /* language tag */
3240 ssh2_pkt_send_noqueue(ssh
, pktout
);
3243 ssh
->close_expected
= TRUE
;
3244 ssh
->clean_exit
= clean_exit
;
3245 ssh_closing((Plug
)ssh
, error
, 0, 0);
3250 * Handle the key exchange and user authentication phases.
3252 static int do_ssh1_login(Ssh ssh
, unsigned char *in
, int inlen
,
3253 struct Packet
*pktin
)
3256 unsigned char cookie
[8], *ptr
;
3257 struct RSAKey servkey
, hostkey
;
3258 struct MD5Context md5c
;
3259 struct do_ssh1_login_state
{
3261 unsigned char *rsabuf
, *keystr1
, *keystr2
;
3262 unsigned long supported_ciphers_mask
, supported_auths_mask
;
3263 int tried_publickey
, tried_agent
;
3264 int tis_auth_refused
, ccard_auth_refused
;
3265 unsigned char session_id
[16];
3267 void *publickey_blob
;
3268 int publickey_bloblen
;
3269 char *publickey_comment
;
3270 int publickey_encrypted
;
3271 prompts_t
*cur_prompt
;
3274 unsigned char request
[5], *response
, *p
;
3285 crState(do_ssh1_login_state
);
3287 crBegin(ssh
->do_ssh1_login_crstate
);
3292 if (pktin
->type
!= SSH1_SMSG_PUBLIC_KEY
) {
3293 bombout(("Public key packet not received"));
3297 logevent("Received public keys");
3299 ptr
= ssh_pkt_getdata(pktin
, 8);
3301 bombout(("SSH-1 public key packet stopped before random cookie"));
3304 memcpy(cookie
, ptr
, 8);
3306 if (!ssh1_pkt_getrsakey(pktin
, &servkey
, &s
->keystr1
) ||
3307 !ssh1_pkt_getrsakey(pktin
, &hostkey
, &s
->keystr2
)) {
3308 bombout(("Failed to read SSH-1 public keys from public key packet"));
3313 * Log the host key fingerprint.
3317 logevent("Host key fingerprint is:");
3318 strcpy(logmsg
, " ");
3319 hostkey
.comment
= NULL
;
3320 rsa_fingerprint(logmsg
+ strlen(logmsg
),
3321 sizeof(logmsg
) - strlen(logmsg
), &hostkey
);
3325 ssh
->v1_remote_protoflags
= ssh_pkt_getuint32(pktin
);
3326 s
->supported_ciphers_mask
= ssh_pkt_getuint32(pktin
);
3327 s
->supported_auths_mask
= ssh_pkt_getuint32(pktin
);
3328 if ((ssh
->remote_bugs
& BUG_CHOKES_ON_RSA
))
3329 s
->supported_auths_mask
&= ~(1 << SSH1_AUTH_RSA
);
3331 ssh
->v1_local_protoflags
=
3332 ssh
->v1_remote_protoflags
& SSH1_PROTOFLAGS_SUPPORTED
;
3333 ssh
->v1_local_protoflags
|= SSH1_PROTOFLAG_SCREEN_NUMBER
;
3336 MD5Update(&md5c
, s
->keystr2
, hostkey
.bytes
);
3337 MD5Update(&md5c
, s
->keystr1
, servkey
.bytes
);
3338 MD5Update(&md5c
, cookie
, 8);
3339 MD5Final(s
->session_id
, &md5c
);
3341 for (i
= 0; i
< 32; i
++)
3342 ssh
->session_key
[i
] = random_byte();
3345 * Verify that the `bits' and `bytes' parameters match.
3347 if (hostkey
.bits
> hostkey
.bytes
* 8 ||
3348 servkey
.bits
> servkey
.bytes
* 8) {
3349 bombout(("SSH-1 public keys were badly formatted"));
3353 s
->len
= (hostkey
.bytes
> servkey
.bytes ? hostkey
.bytes
: servkey
.bytes
);
3355 s
->rsabuf
= snewn(s
->len
, unsigned char);
3358 * Verify the host key.
3362 * First format the key into a string.
3364 int len
= rsastr_len(&hostkey
);
3365 char fingerprint
[100];
3366 char *keystr
= snewn(len
, char);
3367 rsastr_fmt(keystr
, &hostkey
);
3368 rsa_fingerprint(fingerprint
, sizeof(fingerprint
), &hostkey
);
3370 ssh_set_frozen(ssh
, 1);
3371 s
->dlgret
= verify_ssh_host_key(ssh
->frontend
,
3372 ssh
->savedhost
, ssh
->savedport
,
3373 "rsa", keystr
, fingerprint
,
3374 ssh_dialog_callback
, ssh
);
3376 if (s
->dlgret
< 0) {
3380 bombout(("Unexpected data from server while waiting"
3381 " for user host key response"));
3384 } while (pktin
|| inlen
> 0);
3385 s
->dlgret
= ssh
->user_response
;
3387 ssh_set_frozen(ssh
, 0);
3389 if (s
->dlgret
== 0) {
3390 ssh_disconnect(ssh
, "User aborted at host key verification",
3396 for (i
= 0; i
< 32; i
++) {
3397 s
->rsabuf
[i
] = ssh
->session_key
[i
];
3399 s
->rsabuf
[i
] ^= s
->session_id
[i
];
3402 if (hostkey
.bytes
> servkey
.bytes
) {
3403 ret
= rsaencrypt(s
->rsabuf
, 32, &servkey
);
3405 ret
= rsaencrypt(s
->rsabuf
, servkey
.bytes
, &hostkey
);
3407 ret
= rsaencrypt(s
->rsabuf
, 32, &hostkey
);
3409 ret
= rsaencrypt(s
->rsabuf
, hostkey
.bytes
, &servkey
);
3412 bombout(("SSH-1 public key encryptions failed due to bad formatting"));
3416 logevent("Encrypted session key");
3419 int cipher_chosen
= 0, warn
= 0;
3420 char *cipher_string
= NULL
;
3422 for (i
= 0; !cipher_chosen
&& i
< CIPHER_MAX
; i
++) {
3423 int next_cipher
= conf_get_int_int(ssh
->conf
,
3424 CONF_ssh_cipherlist
, i
);
3425 if (next_cipher
== CIPHER_WARN
) {
3426 /* If/when we choose a cipher, warn about it */
3428 } else if (next_cipher
== CIPHER_AES
) {
3429 /* XXX Probably don't need to mention this. */
3430 logevent("AES not supported in SSH-1, skipping");
3432 switch (next_cipher
) {
3433 case CIPHER_3DES
: s
->cipher_type
= SSH_CIPHER_3DES
;
3434 cipher_string
= "3DES"; break;
3435 case CIPHER_BLOWFISH
: s
->cipher_type
= SSH_CIPHER_BLOWFISH
;
3436 cipher_string
= "Blowfish"; break;
3437 case CIPHER_DES
: s
->cipher_type
= SSH_CIPHER_DES
;
3438 cipher_string
= "single-DES"; break;
3440 if (s
->supported_ciphers_mask
& (1 << s
->cipher_type
))
3444 if (!cipher_chosen
) {
3445 if ((s
->supported_ciphers_mask
& (1 << SSH_CIPHER_3DES
)) == 0)
3446 bombout(("Server violates SSH-1 protocol by not "
3447 "supporting 3DES encryption"));
3449 /* shouldn't happen */
3450 bombout(("No supported ciphers found"));
3454 /* Warn about chosen cipher if necessary. */
3456 ssh_set_frozen(ssh
, 1);
3457 s
->dlgret
= askalg(ssh
->frontend
, "cipher", cipher_string
,
3458 ssh_dialog_callback
, ssh
);
3459 if (s
->dlgret
< 0) {
3463 bombout(("Unexpected data from server while waiting"
3464 " for user response"));
3467 } while (pktin
|| inlen
> 0);
3468 s
->dlgret
= ssh
->user_response
;
3470 ssh_set_frozen(ssh
, 0);
3471 if (s
->dlgret
== 0) {
3472 ssh_disconnect(ssh
, "User aborted at cipher warning", NULL
,
3479 switch (s
->cipher_type
) {
3480 case SSH_CIPHER_3DES
:
3481 logevent("Using 3DES encryption");
3483 case SSH_CIPHER_DES
:
3484 logevent("Using single-DES encryption");
3486 case SSH_CIPHER_BLOWFISH
:
3487 logevent("Using Blowfish encryption");
3491 send_packet(ssh
, SSH1_CMSG_SESSION_KEY
,
3492 PKT_CHAR
, s
->cipher_type
,
3493 PKT_DATA
, cookie
, 8,
3494 PKT_CHAR
, (s
->len
* 8) >> 8, PKT_CHAR
, (s
->len
* 8) & 0xFF,
3495 PKT_DATA
, s
->rsabuf
, s
->len
,
3496 PKT_INT
, ssh
->v1_local_protoflags
, PKT_END
);
3498 logevent("Trying to enable encryption...");
3502 ssh
->cipher
= (s
->cipher_type
== SSH_CIPHER_BLOWFISH ?
&ssh_blowfish_ssh1
:
3503 s
->cipher_type
== SSH_CIPHER_DES ?
&ssh_des
:
3505 ssh
->v1_cipher_ctx
= ssh
->cipher
->make_context();
3506 ssh
->cipher
->sesskey(ssh
->v1_cipher_ctx
, ssh
->session_key
);
3507 logeventf(ssh
, "Initialised %s encryption", ssh
->cipher
->text_name
);
3509 ssh
->crcda_ctx
= crcda_make_context();
3510 logevent("Installing CRC compensation attack detector");
3512 if (servkey
.modulus
) {
3513 sfree(servkey
.modulus
);
3514 servkey
.modulus
= NULL
;
3516 if (servkey
.exponent
) {
3517 sfree(servkey
.exponent
);
3518 servkey
.exponent
= NULL
;
3520 if (hostkey
.modulus
) {
3521 sfree(hostkey
.modulus
);
3522 hostkey
.modulus
= NULL
;
3524 if (hostkey
.exponent
) {
3525 sfree(hostkey
.exponent
);
3526 hostkey
.exponent
= NULL
;
3530 if (pktin
->type
!= SSH1_SMSG_SUCCESS
) {
3531 bombout(("Encryption not successfully enabled"));
3535 logevent("Successfully started encryption");
3537 fflush(stdout
); /* FIXME eh? */
3539 if ((ssh
->username
= get_remote_username(ssh
->conf
)) == NULL
) {
3540 int ret
; /* need not be kept over crReturn */
3541 s
->cur_prompt
= new_prompts(ssh
->frontend
);
3542 s
->cur_prompt
->to_server
= TRUE
;
3543 s
->cur_prompt
->name
= dupstr("SSH login name");
3544 add_prompt(s
->cur_prompt
, dupstr("login as: "), TRUE
);
3545 ret
= get_userpass_input(s
->cur_prompt
, NULL
, 0);
3548 crWaitUntil(!pktin
);
3549 ret
= get_userpass_input(s
->cur_prompt
, in
, inlen
);
3554 * Failed to get a username. Terminate.
3556 free_prompts(s
->cur_prompt
);
3557 ssh_disconnect(ssh
, "No username provided", NULL
, 0, TRUE
);
3560 ssh
->username
= dupstr(s
->cur_prompt
->prompts
[0]->result
);
3561 free_prompts(s
->cur_prompt
);
3564 send_packet(ssh
, SSH1_CMSG_USER
, PKT_STR
, ssh
->username
, PKT_END
);
3566 char *userlog
= dupprintf("Sent username \"%s\"", ssh
->username
);
3568 if (flags
& FLAG_INTERACTIVE
&&
3569 (!((flags
& FLAG_STDERR
) && (flags
& FLAG_VERBOSE
)))) {
3570 c_write_str(ssh
, userlog
);
3571 c_write_str(ssh
, "\r\n");
3579 if ((s
->supported_auths_mask
& (1 << SSH1_AUTH_RSA
)) == 0) {
3580 /* We must not attempt PK auth. Pretend we've already tried it. */
3581 s
->tried_publickey
= s
->tried_agent
= 1;
3583 s
->tried_publickey
= s
->tried_agent
= 0;
3585 s
->tis_auth_refused
= s
->ccard_auth_refused
= 0;
3587 * Load the public half of any configured keyfile for later use.
3589 s
->keyfile
= conf_get_filename(ssh
->conf
, CONF_keyfile
);
3590 if (!filename_is_null(s
->keyfile
)) {
3592 logeventf(ssh
, "Reading private key file \"%.150s\"",
3593 filename_to_str(s
->keyfile
));
3594 keytype
= key_type(s
->keyfile
);
3595 if (keytype
== SSH_KEYTYPE_SSH1
) {
3597 if (rsakey_pubblob(s
->keyfile
,
3598 &s
->publickey_blob
, &s
->publickey_bloblen
,
3599 &s
->publickey_comment
, &error
)) {
3600 s
->publickey_encrypted
= rsakey_encrypted(s
->keyfile
,
3604 logeventf(ssh
, "Unable to load private key (%s)", error
);
3605 msgbuf
= dupprintf("Unable to load private key file "
3606 "\"%.150s\" (%s)\r\n",
3607 filename_to_str(s
->keyfile
),
3609 c_write_str(ssh
, msgbuf
);
3611 s
->publickey_blob
= NULL
;
3615 logeventf(ssh
, "Unable to use this key file (%s)",
3616 key_type_to_str(keytype
));
3617 msgbuf
= dupprintf("Unable to use key file \"%.150s\""
3619 filename_to_str(s
->keyfile
),
3620 key_type_to_str(keytype
));
3621 c_write_str(ssh
, msgbuf
);
3623 s
->publickey_blob
= NULL
;
3626 s
->publickey_blob
= NULL
;
3628 while (pktin
->type
== SSH1_SMSG_FAILURE
) {
3629 s
->pwpkt_type
= SSH1_CMSG_AUTH_PASSWORD
;
3631 if (conf_get_int(ssh
->conf
, CONF_tryagent
) && agent_exists() && !s
->tried_agent
) {
3633 * Attempt RSA authentication using Pageant.
3639 logevent("Pageant is running. Requesting keys.");
3641 /* Request the keys held by the agent. */
3642 PUT_32BIT(s
->request
, 1);
3643 s
->request
[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES
;
3644 if (!agent_query(s
->request
, 5, &r
, &s
->responselen
,
3645 ssh_agent_callback
, ssh
)) {
3649 bombout(("Unexpected data from server while waiting"
3650 " for agent response"));
3653 } while (pktin
|| inlen
> 0);
3654 r
= ssh
->agent_response
;
3655 s
->responselen
= ssh
->agent_response_len
;
3657 s
->response
= (unsigned char *) r
;
3658 if (s
->response
&& s
->responselen
>= 5 &&
3659 s
->response
[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER
) {
3660 s
->p
= s
->response
+ 5;
3661 s
->nkeys
= GET_32BIT(s
->p
);
3663 logeventf(ssh
, "Pageant has %d SSH-1 keys", s
->nkeys
);
3664 for (s
->keyi
= 0; s
->keyi
< s
->nkeys
; s
->keyi
++) {
3665 unsigned char *pkblob
= s
->p
;
3669 do { /* do while (0) to make breaking easy */
3670 n
= ssh1_read_bignum
3671 (s
->p
, s
->responselen
-(s
->p
-s
->response
),
3676 n
= ssh1_read_bignum
3677 (s
->p
, s
->responselen
-(s
->p
-s
->response
),
3682 if (s
->responselen
- (s
->p
-s
->response
) < 4)
3684 s
->commentlen
= GET_32BIT(s
->p
);
3686 if (s
->responselen
- (s
->p
-s
->response
) <
3689 s
->commentp
= (char *)s
->p
;
3690 s
->p
+= s
->commentlen
;
3694 logevent("Pageant key list packet was truncated");
3698 if (s
->publickey_blob
) {
3699 if (!memcmp(pkblob
, s
->publickey_blob
,
3700 s
->publickey_bloblen
)) {
3701 logeventf(ssh
, "Pageant key #%d matches "
3702 "configured key file", s
->keyi
);
3703 s
->tried_publickey
= 1;
3705 /* Skip non-configured key */
3708 logeventf(ssh
, "Trying Pageant key #%d", s
->keyi
);
3709 send_packet(ssh
, SSH1_CMSG_AUTH_RSA
,
3710 PKT_BIGNUM
, s
->key
.modulus
, PKT_END
);
3712 if (pktin
->type
!= SSH1_SMSG_AUTH_RSA_CHALLENGE
) {
3713 logevent("Key refused");
3716 logevent("Received RSA challenge");
3717 if ((s
->challenge
= ssh1_pkt_getmp(pktin
)) == NULL
) {
3718 bombout(("Server's RSA challenge was badly formatted"));
3723 char *agentreq
, *q
, *ret
;
3726 len
= 1 + 4; /* message type, bit count */
3727 len
+= ssh1_bignum_length(s
->key
.exponent
);
3728 len
+= ssh1_bignum_length(s
->key
.modulus
);
3729 len
+= ssh1_bignum_length(s
->challenge
);
3730 len
+= 16; /* session id */
3731 len
+= 4; /* response format */
3732 agentreq
= snewn(4 + len
, char);
3733 PUT_32BIT(agentreq
, len
);
3735 *q
++ = SSH1_AGENTC_RSA_CHALLENGE
;
3736 PUT_32BIT(q
, bignum_bitcount(s
->key
.modulus
));
3738 q
+= ssh1_write_bignum(q
, s
->key
.exponent
);
3739 q
+= ssh1_write_bignum(q
, s
->key
.modulus
);
3740 q
+= ssh1_write_bignum(q
, s
->challenge
);
3741 memcpy(q
, s
->session_id
, 16);
3743 PUT_32BIT(q
, 1); /* response format */
3744 if (!agent_query(agentreq
, len
+ 4, &vret
, &retlen
,
3745 ssh_agent_callback
, ssh
)) {
3750 bombout(("Unexpected data from server"
3751 " while waiting for agent"
3755 } while (pktin
|| inlen
> 0);
3756 vret
= ssh
->agent_response
;
3757 retlen
= ssh
->agent_response_len
;
3762 if (ret
[4] == SSH1_AGENT_RSA_RESPONSE
) {
3763 logevent("Sending Pageant's response");
3764 send_packet(ssh
, SSH1_CMSG_AUTH_RSA_RESPONSE
,
3765 PKT_DATA
, ret
+ 5, 16,
3769 if (pktin
->type
== SSH1_SMSG_SUCCESS
) {
3771 ("Pageant's response accepted");
3772 if (flags
& FLAG_VERBOSE
) {
3773 c_write_str(ssh
, "Authenticated using"
3775 c_write(ssh
, s
->commentp
,
3777 c_write_str(ssh
, "\" from agent\r\n");
3782 ("Pageant's response not accepted");
3785 ("Pageant failed to answer challenge");
3789 logevent("No reply received from Pageant");
3792 freebn(s
->key
.exponent
);
3793 freebn(s
->key
.modulus
);
3794 freebn(s
->challenge
);
3799 if (s
->publickey_blob
&& !s
->tried_publickey
)
3800 logevent("Configured key file not in Pageant");
3802 logevent("Failed to get reply from Pageant");
3807 if (s
->publickey_blob
&& !s
->tried_publickey
) {
3809 * Try public key authentication with the specified
3812 int got_passphrase
; /* need not be kept over crReturn */
3813 if (flags
& FLAG_VERBOSE
)
3814 c_write_str(ssh
, "Trying public key authentication.\r\n");
3815 s
->keyfile
= conf_get_filename(ssh
->conf
, CONF_keyfile
);
3816 logeventf(ssh
, "Trying public key \"%s\"",
3817 filename_to_str(s
->keyfile
));
3818 s
->tried_publickey
= 1;
3819 got_passphrase
= FALSE
;
3820 while (!got_passphrase
) {
3822 * Get a passphrase, if necessary.
3824 char *passphrase
= NULL
; /* only written after crReturn */
3826 if (!s
->publickey_encrypted
) {
3827 if (flags
& FLAG_VERBOSE
)
3828 c_write_str(ssh
, "No passphrase required.\r\n");
3831 int ret
; /* need not be kept over crReturn */
3832 s
->cur_prompt
= new_prompts(ssh
->frontend
);
3833 s
->cur_prompt
->to_server
= FALSE
;
3834 s
->cur_prompt
->name
= dupstr("SSH key passphrase");
3835 add_prompt(s
->cur_prompt
,
3836 dupprintf("Passphrase for key \"%.100s\": ",
3837 s
->publickey_comment
), FALSE
);
3838 ret
= get_userpass_input(s
->cur_prompt
, NULL
, 0);
3841 crWaitUntil(!pktin
);
3842 ret
= get_userpass_input(s
->cur_prompt
, in
, inlen
);
3846 /* Failed to get a passphrase. Terminate. */
3847 free_prompts(s
->cur_prompt
);
3848 ssh_disconnect(ssh
, NULL
, "Unable to authenticate",
3852 passphrase
= dupstr(s
->cur_prompt
->prompts
[0]->result
);
3853 free_prompts(s
->cur_prompt
);
3856 * Try decrypting key with passphrase.
3858 s
->keyfile
= conf_get_filename(ssh
->conf
, CONF_keyfile
);
3859 ret
= loadrsakey(s
->keyfile
, &s
->key
, passphrase
,
3862 smemclr(passphrase
, strlen(passphrase
));
3866 /* Correct passphrase. */
3867 got_passphrase
= TRUE
;
3868 } else if (ret
== 0) {
3869 c_write_str(ssh
, "Couldn't load private key from ");
3870 c_write_str(ssh
, filename_to_str(s
->keyfile
));
3871 c_write_str(ssh
, " (");
3872 c_write_str(ssh
, error
);
3873 c_write_str(ssh
, ").\r\n");
3874 got_passphrase
= FALSE
;
3875 break; /* go and try something else */
3876 } else if (ret
== -1) {
3877 c_write_str(ssh
, "Wrong passphrase.\r\n"); /* FIXME */
3878 got_passphrase
= FALSE
;
3881 assert(0 && "unexpected return from loadrsakey()");
3882 got_passphrase
= FALSE
; /* placate optimisers */
3886 if (got_passphrase
) {
3889 * Send a public key attempt.
3891 send_packet(ssh
, SSH1_CMSG_AUTH_RSA
,
3892 PKT_BIGNUM
, s
->key
.modulus
, PKT_END
);
3895 if (pktin
->type
== SSH1_SMSG_FAILURE
) {
3896 c_write_str(ssh
, "Server refused our public key.\r\n");
3897 continue; /* go and try something else */
3899 if (pktin
->type
!= SSH1_SMSG_AUTH_RSA_CHALLENGE
) {
3900 bombout(("Bizarre response to offer of public key"));
3906 unsigned char buffer
[32];
3907 Bignum challenge
, response
;
3909 if ((challenge
= ssh1_pkt_getmp(pktin
)) == NULL
) {
3910 bombout(("Server's RSA challenge was badly formatted"));
3913 response
= rsadecrypt(challenge
, &s
->key
);
3914 freebn(s
->key
.private_exponent
);/* burn the evidence */
3916 for (i
= 0; i
< 32; i
++) {
3917 buffer
[i
] = bignum_byte(response
, 31 - i
);
3921 MD5Update(&md5c
, buffer
, 32);
3922 MD5Update(&md5c
, s
->session_id
, 16);
3923 MD5Final(buffer
, &md5c
);
3925 send_packet(ssh
, SSH1_CMSG_AUTH_RSA_RESPONSE
,
3926 PKT_DATA
, buffer
, 16, PKT_END
);
3933 if (pktin
->type
== SSH1_SMSG_FAILURE
) {
3934 if (flags
& FLAG_VERBOSE
)
3935 c_write_str(ssh
, "Failed to authenticate with"
3936 " our public key.\r\n");
3937 continue; /* go and try something else */
3938 } else if (pktin
->type
!= SSH1_SMSG_SUCCESS
) {
3939 bombout(("Bizarre response to RSA authentication response"));
3943 break; /* we're through! */
3949 * Otherwise, try various forms of password-like authentication.
3951 s
->cur_prompt
= new_prompts(ssh
->frontend
);
3953 if (conf_get_int(ssh
->conf
, CONF_try_tis_auth
) &&
3954 (s
->supported_auths_mask
& (1 << SSH1_AUTH_TIS
)) &&
3955 !s
->tis_auth_refused
) {
3956 s
->pwpkt_type
= SSH1_CMSG_AUTH_TIS_RESPONSE
;
3957 logevent("Requested TIS authentication");
3958 send_packet(ssh
, SSH1_CMSG_AUTH_TIS
, PKT_END
);
3960 if (pktin
->type
!= SSH1_SMSG_AUTH_TIS_CHALLENGE
) {
3961 logevent("TIS authentication declined");
3962 if (flags
& FLAG_INTERACTIVE
)
3963 c_write_str(ssh
, "TIS authentication refused.\r\n");
3964 s
->tis_auth_refused
= 1;
3969 char *instr_suf
, *prompt
;
3971 ssh_pkt_getstring(pktin
, &challenge
, &challengelen
);
3973 bombout(("TIS challenge packet was badly formed"));
3976 logevent("Received TIS challenge");
3977 s
->cur_prompt
->to_server
= TRUE
;
3978 s
->cur_prompt
->name
= dupstr("SSH TIS authentication");
3979 /* Prompt heuristic comes from OpenSSH */
3980 if (memchr(challenge
, '\n', challengelen
)) {
3981 instr_suf
= dupstr("");
3982 prompt
= dupprintf("%.*s", challengelen
, challenge
);
3984 instr_suf
= dupprintf("%.*s", challengelen
, challenge
);
3985 prompt
= dupstr("Response: ");
3987 s
->cur_prompt
->instruction
=
3988 dupprintf("Using TIS authentication.%s%s",
3989 (*instr_suf
) ?
"\n" : "",
3991 s
->cur_prompt
->instr_reqd
= TRUE
;
3992 add_prompt(s
->cur_prompt
, prompt
, FALSE
);
3996 if (conf_get_int(ssh
->conf
, CONF_try_tis_auth
) &&
3997 (s
->supported_auths_mask
& (1 << SSH1_AUTH_CCARD
)) &&
3998 !s
->ccard_auth_refused
) {
3999 s
->pwpkt_type
= SSH1_CMSG_AUTH_CCARD_RESPONSE
;
4000 logevent("Requested CryptoCard authentication");
4001 send_packet(ssh
, SSH1_CMSG_AUTH_CCARD
, PKT_END
);
4003 if (pktin
->type
!= SSH1_SMSG_AUTH_CCARD_CHALLENGE
) {
4004 logevent("CryptoCard authentication declined");
4005 c_write_str(ssh
, "CryptoCard authentication refused.\r\n");
4006 s
->ccard_auth_refused
= 1;
4011 char *instr_suf
, *prompt
;
4013 ssh_pkt_getstring(pktin
, &challenge
, &challengelen
);
4015 bombout(("CryptoCard challenge packet was badly formed"));
4018 logevent("Received CryptoCard challenge");
4019 s
->cur_prompt
->to_server
= TRUE
;
4020 s
->cur_prompt
->name
= dupstr("SSH CryptoCard authentication");
4021 s
->cur_prompt
->name_reqd
= FALSE
;
4022 /* Prompt heuristic comes from OpenSSH */
4023 if (memchr(challenge
, '\n', challengelen
)) {
4024 instr_suf
= dupstr("");
4025 prompt
= dupprintf("%.*s", challengelen
, challenge
);
4027 instr_suf
= dupprintf("%.*s", challengelen
, challenge
);
4028 prompt
= dupstr("Response: ");
4030 s
->cur_prompt
->instruction
=
4031 dupprintf("Using CryptoCard authentication.%s%s",
4032 (*instr_suf
) ?
"\n" : "",
4034 s
->cur_prompt
->instr_reqd
= TRUE
;
4035 add_prompt(s
->cur_prompt
, prompt
, FALSE
);
4039 if (s
->pwpkt_type
== SSH1_CMSG_AUTH_PASSWORD
) {
4040 if ((s
->supported_auths_mask
& (1 << SSH1_AUTH_PASSWORD
)) == 0) {
4041 bombout(("No supported authentication methods available"));
4044 s
->cur_prompt
->to_server
= TRUE
;
4045 s
->cur_prompt
->name
= dupstr("SSH password");
4046 add_prompt(s
->cur_prompt
, dupprintf("%s@%s's password: ",
4047 ssh
->username
, ssh
->savedhost
),
4052 * Show password prompt, having first obtained it via a TIS
4053 * or CryptoCard exchange if we're doing TIS or CryptoCard
4057 int ret
; /* need not be kept over crReturn */
4058 ret
= get_userpass_input(s
->cur_prompt
, NULL
, 0);
4061 crWaitUntil(!pktin
);
4062 ret
= get_userpass_input(s
->cur_prompt
, in
, inlen
);
4067 * Failed to get a password (for example
4068 * because one was supplied on the command line
4069 * which has already failed to work). Terminate.
4071 free_prompts(s
->cur_prompt
);
4072 ssh_disconnect(ssh
, NULL
, "Unable to authenticate", 0, TRUE
);
4077 if (s
->pwpkt_type
== SSH1_CMSG_AUTH_PASSWORD
) {
4079 * Defence against traffic analysis: we send a
4080 * whole bunch of packets containing strings of
4081 * different lengths. One of these strings is the
4082 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
4083 * The others are all random data in
4084 * SSH1_MSG_IGNORE packets. This way a passive
4085 * listener can't tell which is the password, and
4086 * hence can't deduce the password length.
4088 * Anybody with a password length greater than 16
4089 * bytes is going to have enough entropy in their
4090 * password that a listener won't find it _that_
4091 * much help to know how long it is. So what we'll
4094 * - if password length < 16, we send 15 packets
4095 * containing string lengths 1 through 15
4097 * - otherwise, we let N be the nearest multiple
4098 * of 8 below the password length, and send 8
4099 * packets containing string lengths N through
4100 * N+7. This won't obscure the order of
4101 * magnitude of the password length, but it will
4102 * introduce a bit of extra uncertainty.
4104 * A few servers can't deal with SSH1_MSG_IGNORE, at
4105 * least in this context. For these servers, we need
4106 * an alternative defence. We make use of the fact
4107 * that the password is interpreted as a C string:
4108 * so we can append a NUL, then some random data.
4110 * A few servers can deal with neither SSH1_MSG_IGNORE
4111 * here _nor_ a padded password string.
4112 * For these servers we are left with no defences
4113 * against password length sniffing.
4115 if (!(ssh
->remote_bugs
& BUG_CHOKES_ON_SSH1_IGNORE
) &&
4116 !(ssh
->remote_bugs
& BUG_NEEDS_SSH1_PLAIN_PASSWORD
)) {
4118 * The server can deal with SSH1_MSG_IGNORE, so
4119 * we can use the primary defence.
4121 int bottom
, top
, pwlen
, i
;
4124 pwlen
= strlen(s
->cur_prompt
->prompts
[0]->result
);
4126 bottom
= 0; /* zero length passwords are OK! :-) */
4129 bottom
= pwlen
& ~7;
4133 assert(pwlen
>= bottom
&& pwlen
<= top
);
4135 randomstr
= snewn(top
+ 1, char);
4137 for (i
= bottom
; i
<= top
; i
++) {
4139 defer_packet(ssh
, s
->pwpkt_type
,
4140 PKTT_PASSWORD
, PKT_STR
,
4141 s
->cur_prompt
->prompts
[0]->result
,
4142 PKTT_OTHER
, PKT_END
);
4144 for (j
= 0; j
< i
; j
++) {
4146 randomstr
[j
] = random_byte();
4147 } while (randomstr
[j
] == '\0');
4149 randomstr
[i
] = '\0';
4150 defer_packet(ssh
, SSH1_MSG_IGNORE
,
4151 PKT_STR
, randomstr
, PKT_END
);
4154 logevent("Sending password with camouflage packets");
4155 ssh_pkt_defersend(ssh
);
4158 else if (!(ssh
->remote_bugs
& BUG_NEEDS_SSH1_PLAIN_PASSWORD
)) {
4160 * The server can't deal with SSH1_MSG_IGNORE
4161 * but can deal with padded passwords, so we
4162 * can use the secondary defence.
4168 len
= strlen(s
->cur_prompt
->prompts
[0]->result
);
4169 if (len
< sizeof(string
)) {
4171 strcpy(string
, s
->cur_prompt
->prompts
[0]->result
);
4172 len
++; /* cover the zero byte */
4173 while (len
< sizeof(string
)) {
4174 string
[len
++] = (char) random_byte();
4177 ss
= s
->cur_prompt
->prompts
[0]->result
;
4179 logevent("Sending length-padded password");
4180 send_packet(ssh
, s
->pwpkt_type
, PKTT_PASSWORD
,
4181 PKT_INT
, len
, PKT_DATA
, ss
, len
,
4182 PKTT_OTHER
, PKT_END
);
4185 * The server is believed unable to cope with
4186 * any of our password camouflage methods.
4189 len
= strlen(s
->cur_prompt
->prompts
[0]->result
);
4190 logevent("Sending unpadded password");
4191 send_packet(ssh
, s
->pwpkt_type
,
4192 PKTT_PASSWORD
, PKT_INT
, len
,
4193 PKT_DATA
, s
->cur_prompt
->prompts
[0]->result
, len
,
4194 PKTT_OTHER
, PKT_END
);
4197 send_packet(ssh
, s
->pwpkt_type
, PKTT_PASSWORD
,
4198 PKT_STR
, s
->cur_prompt
->prompts
[0]->result
,
4199 PKTT_OTHER
, PKT_END
);
4201 logevent("Sent password");
4202 free_prompts(s
->cur_prompt
);
4204 if (pktin
->type
== SSH1_SMSG_FAILURE
) {
4205 if (flags
& FLAG_VERBOSE
)
4206 c_write_str(ssh
, "Access denied\r\n");
4207 logevent("Authentication refused");
4208 } else if (pktin
->type
!= SSH1_SMSG_SUCCESS
) {
4209 bombout(("Strange packet received, type %d", pktin
->type
));
4215 if (s
->publickey_blob
) {
4216 sfree(s
->publickey_blob
);
4217 sfree(s
->publickey_comment
);
4220 logevent("Authentication successful");
4225 static void ssh_channel_try_eof(struct ssh_channel
*c
)
4228 assert(c
->pending_eof
); /* precondition for calling us */
4230 return; /* can't close: not even opened yet */
4231 if (ssh
->version
== 2 && bufchain_size(&c
->v
.v2
.outbuffer
) > 0)
4232 return; /* can't send EOF: pending outgoing data */
4234 if (ssh
->version
== 1) {
4235 send_packet(ssh
, SSH1_MSG_CHANNEL_CLOSE
, PKT_INT
, c
->remoteid
,
4237 c
->closes
|= CLOSES_SENT_EOF
;
4239 struct Packet
*pktout
;
4240 pktout
= ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF
);
4241 ssh2_pkt_adduint32(pktout
, c
->remoteid
);
4242 ssh2_pkt_send(ssh
, pktout
);
4243 c
->closes
|= CLOSES_SENT_EOF
;
4244 if (!((CLOSES_SENT_EOF
| CLOSES_RCVD_EOF
) & ~c
->closes
)) {
4246 * Also send MSG_CLOSE.
4248 pktout
= ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE
);
4249 ssh2_pkt_adduint32(pktout
, c
->remoteid
);
4250 ssh2_pkt_send(ssh
, pktout
);
4251 c
->closes
|= CLOSES_SENT_CLOSE
;
4254 c
->pending_eof
= FALSE
; /* we've sent it now */
4257 void sshfwd_write_eof(struct ssh_channel
*c
)
4261 if (ssh
->state
== SSH_STATE_CLOSED
)
4264 if (c
->closes
& CLOSES_SENT_EOF
)
4267 c
->pending_eof
= TRUE
;
4268 ssh_channel_try_eof(c
);
4271 void sshfwd_unclean_close(struct ssh_channel
*c
)
4274 struct Packet
*pktout
;
4276 if (ssh
->state
== SSH_STATE_CLOSED
)
4279 if (!(c
->closes
& CLOSES_SENT_CLOSE
)) {
4280 pktout
= ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE
);
4281 ssh2_pkt_adduint32(pktout
, c
->remoteid
);
4282 ssh2_pkt_send(ssh
, pktout
);
4283 c
->closes
|= CLOSES_SENT_EOF
| CLOSES_SENT_CLOSE
;
4288 x11_close(c
->u
.x11
.s
);
4291 case CHAN_SOCKDATA_DORMANT
:
4292 pfd_close(c
->u
.pfd
.s
);
4295 c
->type
= CHAN_ZOMBIE
;
4297 ssh2_channel_check_close(c
);
4300 int sshfwd_write(struct ssh_channel
*c
, char *buf
, int len
)
4304 if (ssh
->state
== SSH_STATE_CLOSED
)
4307 if (ssh
->version
== 1) {
4308 send_packet(ssh
, SSH1_MSG_CHANNEL_DATA
,
4309 PKT_INT
, c
->remoteid
,
4310 PKT_INT
, len
, PKTT_DATA
, PKT_DATA
, buf
, len
,
4311 PKTT_OTHER
, PKT_END
);
4313 * In SSH-1 we can return 0 here - implying that forwarded
4314 * connections are never individually throttled - because
4315 * the only circumstance that can cause throttling will be
4316 * the whole SSH connection backing up, in which case
4317 * _everything_ will be throttled as a whole.
4321 ssh2_add_channel_data(c
, buf
, len
);
4322 return ssh2_try_send(c
);
4326 void sshfwd_unthrottle(struct ssh_channel
*c
, int bufsize
)
4331 if (ssh
->state
== SSH_STATE_CLOSED
)
4334 if (ssh
->version
== 1) {
4335 buflimit
= SSH1_BUFFER_LIMIT
;
4337 buflimit
= c
->v
.v2
.locmaxwin
;
4338 ssh2_set_window(c
, bufsize
< buflimit ? buflimit
- bufsize
: 0);
4340 if (c
->throttling_conn
&& bufsize
<= buflimit
) {
4341 c
->throttling_conn
= 0;
4342 ssh_throttle_conn(ssh
, -1);
4346 static void ssh_queueing_handler(Ssh ssh
, struct Packet
*pktin
)
4348 struct queued_handler
*qh
= ssh
->qhead
;
4352 assert(pktin
->type
== qh
->msg1
|| pktin
->type
== qh
->msg2
);
4355 assert(ssh
->packet_dispatch
[qh
->msg1
] == ssh_queueing_handler
);
4356 ssh
->packet_dispatch
[qh
->msg1
] = NULL
;
4359 assert(ssh
->packet_dispatch
[qh
->msg2
] == ssh_queueing_handler
);
4360 ssh
->packet_dispatch
[qh
->msg2
] = NULL
;
4364 ssh
->qhead
= qh
->next
;
4366 if (ssh
->qhead
->msg1
> 0) {
4367 assert(ssh
->packet_dispatch
[ssh
->qhead
->msg1
] == NULL
);
4368 ssh
->packet_dispatch
[ssh
->qhead
->msg1
] = ssh_queueing_handler
;
4370 if (ssh
->qhead
->msg2
> 0) {
4371 assert(ssh
->packet_dispatch
[ssh
->qhead
->msg2
] == NULL
);
4372 ssh
->packet_dispatch
[ssh
->qhead
->msg2
] = ssh_queueing_handler
;
4375 ssh
->qhead
= ssh
->qtail
= NULL
;
4376 ssh
->packet_dispatch
[pktin
->type
] = NULL
;
4379 qh
->handler(ssh
, pktin
, qh
->ctx
);
4384 static void ssh_queue_handler(Ssh ssh
, int msg1
, int msg2
,
4385 chandler_fn_t handler
, void *ctx
)
4387 struct queued_handler
*qh
;
4389 qh
= snew(struct queued_handler
);
4392 qh
->handler
= handler
;
4396 if (ssh
->qtail
== NULL
) {
4400 assert(ssh
->packet_dispatch
[qh
->msg1
] == NULL
);
4401 ssh
->packet_dispatch
[qh
->msg1
] = ssh_queueing_handler
;
4404 assert(ssh
->packet_dispatch
[qh
->msg2
] == NULL
);
4405 ssh
->packet_dispatch
[qh
->msg2
] = ssh_queueing_handler
;
4408 ssh
->qtail
->next
= qh
;
4413 static void ssh_rportfwd_succfail(Ssh ssh
, struct Packet
*pktin
, void *ctx
)
4415 struct ssh_rportfwd
*rpf
, *pf
= (struct ssh_rportfwd
*)ctx
;
4417 if (pktin
->type
== (ssh
->version
== 1 ? SSH1_SMSG_SUCCESS
:
4418 SSH2_MSG_REQUEST_SUCCESS
)) {
4419 logeventf(ssh
, "Remote port forwarding from %s enabled",
4422 logeventf(ssh
, "Remote port forwarding from %s refused",
4425 rpf
= del234(ssh
->rportfwds
, pf
);
4427 pf
->pfrec
->remote
= NULL
;
4432 static void ssh_setup_portfwd(Ssh ssh
, Conf
*conf
)
4434 struct ssh_portfwd
*epf
;
4438 if (!ssh
->portfwds
) {
4439 ssh
->portfwds
= newtree234(ssh_portcmp
);
4442 * Go through the existing port forwardings and tag them
4443 * with status==DESTROY. Any that we want to keep will be
4444 * re-enabled (status==KEEP) as we go through the
4445 * configuration and find out which bits are the same as
4448 struct ssh_portfwd
*epf
;
4450 for (i
= 0; (epf
= index234(ssh
->portfwds
, i
)) != NULL
; i
++)
4451 epf
->status
= DESTROY
;
4454 for (val
= conf_get_str_strs(conf
, CONF_portfwd
, NULL
, &key
);
4456 val
= conf_get_str_strs(conf
, CONF_portfwd
, key
, &key
)) {
4457 char *kp
, *kp2
, *vp
, *vp2
;
4458 char address_family
, type
;
4459 int sport
,dport
,sserv
,dserv
;
4460 char *sports
, *dports
, *saddr
, *host
;
4464 address_family
= 'A';
4466 if (*kp
== 'A' || *kp
== '4' || *kp
== '6')
4467 address_family
= *kp
++;
4468 if (*kp
== 'L' || *kp
== 'R')
4471 if ((kp2
= strchr(kp
, ':')) != NULL
) {
4473 * There's a colon in the middle of the source port
4474 * string, which means that the part before it is
4475 * actually a source address.
4477 saddr
= dupprintf("%.*s", (int)(kp2
- kp
), kp
);
4483 sport
= atoi(sports
);
4487 sport
= net_service_lookup(sports
);
4489 logeventf(ssh
, "Service lookup failed for source"
4490 " port \"%s\"", sports
);
4494 if (type
== 'L' && !strcmp(val
, "D")) {
4495 /* dynamic forwarding */
4502 /* ordinary forwarding */
4504 vp2
= vp
+ strcspn(vp
, ":");
4505 host
= dupprintf("%.*s", (int)(vp2
- vp
), vp
);
4509 dport
= atoi(dports
);
4513 dport
= net_service_lookup(dports
);
4515 logeventf(ssh
, "Service lookup failed for destination"
4516 " port \"%s\"", dports
);
4521 if (sport
&& dport
) {
4522 /* Set up a description of the source port. */
4523 struct ssh_portfwd
*pfrec
, *epfrec
;
4525 pfrec
= snew(struct ssh_portfwd
);
4527 pfrec
->saddr
= saddr
;
4528 pfrec
->sserv
= sserv ?
dupstr(sports
) : NULL
;
4529 pfrec
->sport
= sport
;
4530 pfrec
->daddr
= host
;
4531 pfrec
->dserv
= dserv ?
dupstr(dports
) : NULL
;
4532 pfrec
->dport
= dport
;
4533 pfrec
->local
= NULL
;
4534 pfrec
->remote
= NULL
;
4535 pfrec
->addressfamily
= (address_family
== '4' ? ADDRTYPE_IPV4
:
4536 address_family
== '6' ? ADDRTYPE_IPV6
:
4539 epfrec
= add234(ssh
->portfwds
, pfrec
);
4540 if (epfrec
!= pfrec
) {
4541 if (epfrec
->status
== DESTROY
) {
4543 * We already have a port forwarding up and running
4544 * with precisely these parameters. Hence, no need
4545 * to do anything; simply re-tag the existing one
4548 epfrec
->status
= KEEP
;
4551 * Anything else indicates that there was a duplicate
4552 * in our input, which we'll silently ignore.
4554 free_portfwd(pfrec
);
4556 pfrec
->status
= CREATE
;
4565 * Now go through and destroy any port forwardings which were
4568 for (i
= 0; (epf
= index234(ssh
->portfwds
, i
)) != NULL
; i
++)
4569 if (epf
->status
== DESTROY
) {
4572 message
= dupprintf("%s port forwarding from %s%s%d",
4573 epf
->type
== 'L' ?
"local" :
4574 epf
->type
== 'R' ?
"remote" : "dynamic",
4575 epf
->saddr ? epf
->saddr
: "",
4576 epf
->saddr ?
":" : "",
4579 if (epf
->type
!= 'D') {
4580 char *msg2
= dupprintf("%s to %s:%d", message
,
4581 epf
->daddr
, epf
->dport
);
4586 logeventf(ssh
, "Cancelling %s", message
);
4589 /* epf->remote or epf->local may be NULL if setting up a
4590 * forwarding failed. */
4592 struct ssh_rportfwd
*rpf
= epf
->remote
;
4593 struct Packet
*pktout
;
4596 * Cancel the port forwarding at the server
4599 if (ssh
->version
== 1) {
4601 * We cannot cancel listening ports on the
4602 * server side in SSH-1! There's no message
4603 * to support it. Instead, we simply remove
4604 * the rportfwd record from the local end
4605 * so that any connections the server tries
4606 * to make on it are rejected.
4609 pktout
= ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST
);
4610 ssh2_pkt_addstring(pktout
, "cancel-tcpip-forward");
4611 ssh2_pkt_addbool(pktout
, 0);/* _don't_ want reply */
4613 ssh2_pkt_addstring(pktout
, epf
->saddr
);
4614 } else if (conf_get_int(conf
, CONF_rport_acceptall
)) {
4615 /* XXX: rport_acceptall may not represent
4616 * what was used to open the original connection,
4617 * since it's reconfigurable. */
4618 ssh2_pkt_addstring(pktout
, "0.0.0.0");
4620 ssh2_pkt_addstring(pktout
, "127.0.0.1");
4622 ssh2_pkt_adduint32(pktout
, epf
->sport
);
4623 ssh2_pkt_send(ssh
, pktout
);
4626 del234(ssh
->rportfwds
, rpf
);
4628 } else if (epf
->local
) {
4629 pfd_terminate(epf
->local
);
4632 delpos234(ssh
->portfwds
, i
);
4634 i
--; /* so we don't skip one in the list */
4638 * And finally, set up any new port forwardings (status==CREATE).
4640 for (i
= 0; (epf
= index234(ssh
->portfwds
, i
)) != NULL
; i
++)
4641 if (epf
->status
== CREATE
) {
4642 char *sportdesc
, *dportdesc
;
4643 sportdesc
= dupprintf("%s%s%s%s%d%s",
4644 epf
->saddr ? epf
->saddr
: "",
4645 epf
->saddr ?
":" : "",
4646 epf
->sserv ? epf
->sserv
: "",
4647 epf
->sserv ?
"(" : "",
4649 epf
->sserv ?
")" : "");
4650 if (epf
->type
== 'D') {
4653 dportdesc
= dupprintf("%s:%s%s%d%s",
4655 epf
->dserv ? epf
->dserv
: "",
4656 epf
->dserv ?
"(" : "",
4658 epf
->dserv ?
")" : "");
4661 if (epf
->type
== 'L') {
4662 const char *err
= pfd_addforward(epf
->daddr
, epf
->dport
,
4663 epf
->saddr
, epf
->sport
,
4666 epf
->addressfamily
);
4668 logeventf(ssh
, "Local %sport %s forwarding to %s%s%s",
4669 epf
->addressfamily
== ADDRTYPE_IPV4 ?
"IPv4 " :
4670 epf
->addressfamily
== ADDRTYPE_IPV6 ?
"IPv6 " : "",
4671 sportdesc
, dportdesc
,
4672 err ?
" failed: " : "", err ? err
: "");
4673 } else if (epf
->type
== 'D') {
4674 const char *err
= pfd_addforward(NULL
, -1,
4675 epf
->saddr
, epf
->sport
,
4678 epf
->addressfamily
);
4680 logeventf(ssh
, "Local %sport %s SOCKS dynamic forwarding%s%s",
4681 epf
->addressfamily
== ADDRTYPE_IPV4 ?
"IPv4 " :
4682 epf
->addressfamily
== ADDRTYPE_IPV6 ?
"IPv6 " : "",
4684 err ?
" failed: " : "", err ? err
: "");
4686 struct ssh_rportfwd
*pf
;
4689 * Ensure the remote port forwardings tree exists.
4691 if (!ssh
->rportfwds
) {
4692 if (ssh
->version
== 1)
4693 ssh
->rportfwds
= newtree234(ssh_rportcmp_ssh1
);
4695 ssh
->rportfwds
= newtree234(ssh_rportcmp_ssh2
);
4698 pf
= snew(struct ssh_rportfwd
);
4699 strncpy(pf
->dhost
, epf
->daddr
, lenof(pf
->dhost
)-1);
4700 pf
->dhost
[lenof(pf
->dhost
)-1] = '\0';
4701 pf
->dport
= epf
->dport
;
4702 pf
->sport
= epf
->sport
;
4703 if (add234(ssh
->rportfwds
, pf
) != pf
) {
4704 logeventf(ssh
, "Duplicate remote port forwarding to %s:%d",
4705 epf
->daddr
, epf
->dport
);
4708 logeventf(ssh
, "Requesting remote port %s"
4709 " forward to %s", sportdesc
, dportdesc
);
4711 pf
->sportdesc
= sportdesc
;
4716 if (ssh
->version
== 1) {
4717 send_packet(ssh
, SSH1_CMSG_PORT_FORWARD_REQUEST
,
4718 PKT_INT
, epf
->sport
,
4719 PKT_STR
, epf
->daddr
,
4720 PKT_INT
, epf
->dport
,
4722 ssh_queue_handler(ssh
, SSH1_SMSG_SUCCESS
,
4724 ssh_rportfwd_succfail
, pf
);
4726 struct Packet
*pktout
;
4727 pktout
= ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST
);
4728 ssh2_pkt_addstring(pktout
, "tcpip-forward");
4729 ssh2_pkt_addbool(pktout
, 1);/* want reply */
4731 ssh2_pkt_addstring(pktout
, epf
->saddr
);
4732 } else if (conf_get_int(conf
, CONF_rport_acceptall
)) {
4733 ssh2_pkt_addstring(pktout
, "0.0.0.0");
4735 ssh2_pkt_addstring(pktout
, "127.0.0.1");
4737 ssh2_pkt_adduint32(pktout
, epf
->sport
);
4738 ssh2_pkt_send(ssh
, pktout
);
4740 ssh_queue_handler(ssh
, SSH2_MSG_REQUEST_SUCCESS
,
4741 SSH2_MSG_REQUEST_FAILURE
,
4742 ssh_rportfwd_succfail
, pf
);
4751 static void ssh1_smsg_stdout_stderr_data(Ssh ssh
, struct Packet
*pktin
)
4754 int stringlen
, bufsize
;
4756 ssh_pkt_getstring(pktin
, &string
, &stringlen
);
4757 if (string
== NULL
) {
4758 bombout(("Incoming terminal data packet was badly formed"));
4762 bufsize
= from_backend(ssh
->frontend
, pktin
->type
== SSH1_SMSG_STDERR_DATA
,
4764 if (!ssh
->v1_stdout_throttling
&& bufsize
> SSH1_BUFFER_LIMIT
) {
4765 ssh
->v1_stdout_throttling
= 1;
4766 ssh_throttle_conn(ssh
, +1);
4770 static void ssh1_smsg_x11_open(Ssh ssh
, struct Packet
*pktin
)
4772 /* Remote side is trying to open a channel to talk to our
4773 * X-Server. Give them back a local channel number. */
4774 struct ssh_channel
*c
;
4775 int remoteid
= ssh_pkt_getuint32(pktin
);
4777 logevent("Received X11 connect request");
4778 /* Refuse if X11 forwarding is disabled. */
4779 if (!ssh
->X11_fwd_enabled
) {
4780 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_FAILURE
,
4781 PKT_INT
, remoteid
, PKT_END
);
4782 logevent("Rejected X11 connect request");
4784 c
= snew(struct ssh_channel
);
4787 if (x11_init(&c
->u
.x11
.s
, ssh
->x11disp
, c
,
4788 NULL
, -1, ssh
->conf
) != NULL
) {
4789 logevent("Opening X11 forward connection failed");
4791 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_FAILURE
,
4792 PKT_INT
, remoteid
, PKT_END
);
4795 ("Opening X11 forward connection succeeded");
4796 c
->remoteid
= remoteid
;
4797 c
->halfopen
= FALSE
;
4798 c
->localid
= alloc_channel_id(ssh
);
4800 c
->pending_eof
= FALSE
;
4801 c
->throttling_conn
= 0;
4802 c
->type
= CHAN_X11
; /* identify channel type */
4803 add234(ssh
->channels
, c
);
4804 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
,
4805 PKT_INT
, c
->remoteid
, PKT_INT
,
4806 c
->localid
, PKT_END
);
4807 logevent("Opened X11 forward channel");
4812 static void ssh1_smsg_agent_open(Ssh ssh
, struct Packet
*pktin
)
4814 /* Remote side is trying to open a channel to talk to our
4815 * agent. Give them back a local channel number. */
4816 struct ssh_channel
*c
;
4817 int remoteid
= ssh_pkt_getuint32(pktin
);
4819 /* Refuse if agent forwarding is disabled. */
4820 if (!ssh
->agentfwd_enabled
) {
4821 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_FAILURE
,
4822 PKT_INT
, remoteid
, PKT_END
);
4824 c
= snew(struct ssh_channel
);
4826 c
->remoteid
= remoteid
;
4827 c
->halfopen
= FALSE
;
4828 c
->localid
= alloc_channel_id(ssh
);
4830 c
->pending_eof
= FALSE
;
4831 c
->throttling_conn
= 0;
4832 c
->type
= CHAN_AGENT
; /* identify channel type */
4833 c
->u
.a
.lensofar
= 0;
4834 c
->u
.a
.message
= NULL
;
4835 add234(ssh
->channels
, c
);
4836 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
,
4837 PKT_INT
, c
->remoteid
, PKT_INT
, c
->localid
,
4842 static void ssh1_msg_port_open(Ssh ssh
, struct Packet
*pktin
)
4844 /* Remote side is trying to open a channel to talk to a
4845 * forwarded port. Give them back a local channel number. */
4846 struct ssh_channel
*c
;
4847 struct ssh_rportfwd pf
, *pfp
;
4852 c
= snew(struct ssh_channel
);
4855 remoteid
= ssh_pkt_getuint32(pktin
);
4856 ssh_pkt_getstring(pktin
, &host
, &hostsize
);
4857 port
= ssh_pkt_getuint32(pktin
);
4859 if (hostsize
>= lenof(pf
.dhost
))
4860 hostsize
= lenof(pf
.dhost
)-1;
4861 memcpy(pf
.dhost
, host
, hostsize
);
4862 pf
.dhost
[hostsize
] = '\0';
4864 pfp
= find234(ssh
->rportfwds
, &pf
, NULL
);
4867 logeventf(ssh
, "Rejected remote port open request for %s:%d",
4869 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_FAILURE
,
4870 PKT_INT
, remoteid
, PKT_END
);
4872 logeventf(ssh
, "Received remote port open request for %s:%d",
4874 e
= pfd_newconnect(&c
->u
.pfd
.s
, pf
.dhost
, port
,
4875 c
, ssh
->conf
, pfp
->pfrec
->addressfamily
);
4877 logeventf(ssh
, "Port open failed: %s", e
);
4879 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_FAILURE
,
4880 PKT_INT
, remoteid
, PKT_END
);
4882 c
->remoteid
= remoteid
;
4883 c
->halfopen
= FALSE
;
4884 c
->localid
= alloc_channel_id(ssh
);
4886 c
->pending_eof
= FALSE
;
4887 c
->throttling_conn
= 0;
4888 c
->type
= CHAN_SOCKDATA
; /* identify channel type */
4889 add234(ssh
->channels
, c
);
4890 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
,
4891 PKT_INT
, c
->remoteid
, PKT_INT
,
4892 c
->localid
, PKT_END
);
4893 logevent("Forwarded port opened successfully");
4898 static void ssh1_msg_channel_open_confirmation(Ssh ssh
, struct Packet
*pktin
)
4900 unsigned int remoteid
= ssh_pkt_getuint32(pktin
);
4901 unsigned int localid
= ssh_pkt_getuint32(pktin
);
4902 struct ssh_channel
*c
;
4904 c
= find234(ssh
->channels
, &remoteid
, ssh_channelfind
);
4905 if (c
&& c
->type
== CHAN_SOCKDATA_DORMANT
) {
4906 c
->remoteid
= localid
;
4907 c
->halfopen
= FALSE
;
4908 c
->type
= CHAN_SOCKDATA
;
4909 c
->throttling_conn
= 0;
4910 pfd_confirm(c
->u
.pfd
.s
);
4913 if (c
&& c
->pending_eof
) {
4915 * We have a pending close on this channel,
4916 * which we decided on before the server acked
4917 * the channel open. So now we know the
4918 * remoteid, we can close it again.
4920 ssh_channel_try_eof(c
);
4924 static void ssh1_msg_channel_open_failure(Ssh ssh
, struct Packet
*pktin
)
4926 unsigned int remoteid
= ssh_pkt_getuint32(pktin
);
4927 struct ssh_channel
*c
;
4929 c
= find234(ssh
->channels
, &remoteid
, ssh_channelfind
);
4930 if (c
&& c
->type
== CHAN_SOCKDATA_DORMANT
) {
4931 logevent("Forwarded connection refused by server");
4932 pfd_close(c
->u
.pfd
.s
);
4933 del234(ssh
->channels
, c
);
4938 static void ssh1_msg_channel_close(Ssh ssh
, struct Packet
*pktin
)
4940 /* Remote side closes a channel. */
4941 unsigned i
= ssh_pkt_getuint32(pktin
);
4942 struct ssh_channel
*c
;
4943 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
4944 if (c
&& !c
->halfopen
) {
4946 if (pktin
->type
== SSH1_MSG_CHANNEL_CLOSE
&&
4947 !(c
->closes
& CLOSES_RCVD_EOF
)) {
4949 * Received CHANNEL_CLOSE, which we translate into
4952 int send_close
= FALSE
;
4954 c
->closes
|= CLOSES_RCVD_EOF
;
4959 x11_send_eof(c
->u
.x11
.s
);
4964 x11_send_eof(c
->u
.pfd
.s
);
4971 if (send_close
&& !(c
->closes
& CLOSES_SENT_EOF
)) {
4972 send_packet(ssh
, SSH1_MSG_CHANNEL_CLOSE
, PKT_INT
, c
->remoteid
,
4974 c
->closes
|= CLOSES_SENT_EOF
;
4978 if (pktin
->type
== SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION
&&
4979 !(c
->closes
& CLOSES_RCVD_CLOSE
)) {
4981 if (!(c
->closes
& CLOSES_SENT_EOF
)) {
4982 bombout(("Received CHANNEL_CLOSE_CONFIRMATION for channel %d"
4983 " for which we never sent CHANNEL_CLOSE\n", i
));
4986 c
->closes
|= CLOSES_RCVD_CLOSE
;
4989 if (!((CLOSES_SENT_EOF
| CLOSES_RCVD_EOF
) & ~c
->closes
) &&
4990 !(c
->closes
& CLOSES_SENT_CLOSE
)) {
4991 send_packet(ssh
, SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION
,
4992 PKT_INT
, c
->remoteid
, PKT_END
);
4993 c
->closes
|= CLOSES_SENT_CLOSE
;
4996 if (!((CLOSES_SENT_CLOSE
| CLOSES_RCVD_CLOSE
) & ~c
->closes
))
4997 ssh_channel_destroy(c
);
4999 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
5000 pktin
->type
== SSH1_MSG_CHANNEL_CLOSE ?
"" :
5001 "_CONFIRMATION", c ?
"half-open" : "nonexistent",
5006 static void ssh1_msg_channel_data(Ssh ssh
, struct Packet
*pktin
)
5008 /* Data sent down one of our channels. */
5009 int i
= ssh_pkt_getuint32(pktin
);
5012 struct ssh_channel
*c
;
5014 ssh_pkt_getstring(pktin
, &p
, &len
);
5016 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5021 bufsize
= x11_send(c
->u
.x11
.s
, p
, len
);
5024 bufsize
= pfd_send(c
->u
.pfd
.s
, p
, len
);
5027 /* Data for an agent message. Buffer it. */
5029 if (c
->u
.a
.lensofar
< 4) {
5030 unsigned int l
= min(4 - c
->u
.a
.lensofar
, (unsigned)len
);
5031 memcpy(c
->u
.a
.msglen
+ c
->u
.a
.lensofar
, p
,
5035 c
->u
.a
.lensofar
+= l
;
5037 if (c
->u
.a
.lensofar
== 4) {
5039 4 + GET_32BIT(c
->u
.a
.msglen
);
5040 c
->u
.a
.message
= snewn(c
->u
.a
.totallen
,
5042 memcpy(c
->u
.a
.message
, c
->u
.a
.msglen
, 4);
5044 if (c
->u
.a
.lensofar
>= 4 && len
> 0) {
5046 min(c
->u
.a
.totallen
- c
->u
.a
.lensofar
,
5048 memcpy(c
->u
.a
.message
+ c
->u
.a
.lensofar
, p
,
5052 c
->u
.a
.lensofar
+= l
;
5054 if (c
->u
.a
.lensofar
== c
->u
.a
.totallen
) {
5057 if (agent_query(c
->u
.a
.message
,
5060 ssh_agentf_callback
, c
))
5061 ssh_agentf_callback(c
, reply
, replylen
);
5062 sfree(c
->u
.a
.message
);
5063 c
->u
.a
.lensofar
= 0;
5066 bufsize
= 0; /* agent channels never back up */
5069 if (!c
->throttling_conn
&& bufsize
> SSH1_BUFFER_LIMIT
) {
5070 c
->throttling_conn
= 1;
5071 ssh_throttle_conn(ssh
, +1);
5076 static void ssh1_smsg_exit_status(Ssh ssh
, struct Packet
*pktin
)
5078 ssh
->exitcode
= ssh_pkt_getuint32(pktin
);
5079 logeventf(ssh
, "Server sent command exit status %d", ssh
->exitcode
);
5080 send_packet(ssh
, SSH1_CMSG_EXIT_CONFIRMATION
, PKT_END
);
5082 * In case `helpful' firewalls or proxies tack
5083 * extra human-readable text on the end of the
5084 * session which we might mistake for another
5085 * encrypted packet, we close the session once
5086 * we've sent EXIT_CONFIRMATION.
5088 ssh_disconnect(ssh
, NULL
, NULL
, 0, TRUE
);
5091 /* Helper function to deal with sending tty modes for REQUEST_PTY */
5092 static void ssh1_send_ttymode(void *data
, char *mode
, char *val
)
5094 struct Packet
*pktout
= (struct Packet
*)data
;
5096 unsigned int arg
= 0;
5097 while (strcmp(mode
, ssh_ttymodes
[i
].mode
) != 0) i
++;
5098 if (i
== lenof(ssh_ttymodes
)) return;
5099 switch (ssh_ttymodes
[i
].type
) {
5101 arg
= ssh_tty_parse_specchar(val
);
5104 arg
= ssh_tty_parse_boolean(val
);
5107 ssh2_pkt_addbyte(pktout
, ssh_ttymodes
[i
].opcode
);
5108 ssh2_pkt_addbyte(pktout
, arg
);
5112 static void do_ssh1_connection(Ssh ssh
, unsigned char *in
, int inlen
,
5113 struct Packet
*pktin
)
5115 crBegin(ssh
->do_ssh1_connection_crstate
);
5117 ssh
->packet_dispatch
[SSH1_SMSG_STDOUT_DATA
] =
5118 ssh
->packet_dispatch
[SSH1_SMSG_STDERR_DATA
] =
5119 ssh1_smsg_stdout_stderr_data
;
5121 ssh
->packet_dispatch
[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
] =
5122 ssh1_msg_channel_open_confirmation
;
5123 ssh
->packet_dispatch
[SSH1_MSG_CHANNEL_OPEN_FAILURE
] =
5124 ssh1_msg_channel_open_failure
;
5125 ssh
->packet_dispatch
[SSH1_MSG_CHANNEL_CLOSE
] =
5126 ssh
->packet_dispatch
[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION
] =
5127 ssh1_msg_channel_close
;
5128 ssh
->packet_dispatch
[SSH1_MSG_CHANNEL_DATA
] = ssh1_msg_channel_data
;
5129 ssh
->packet_dispatch
[SSH1_SMSG_EXIT_STATUS
] = ssh1_smsg_exit_status
;
5131 if (conf_get_int(ssh
->conf
, CONF_agentfwd
) && agent_exists()) {
5132 logevent("Requesting agent forwarding");
5133 send_packet(ssh
, SSH1_CMSG_AGENT_REQUEST_FORWARDING
, PKT_END
);
5137 if (pktin
->type
!= SSH1_SMSG_SUCCESS
5138 && pktin
->type
!= SSH1_SMSG_FAILURE
) {
5139 bombout(("Protocol confusion"));
5141 } else if (pktin
->type
== SSH1_SMSG_FAILURE
) {
5142 logevent("Agent forwarding refused");
5144 logevent("Agent forwarding enabled");
5145 ssh
->agentfwd_enabled
= TRUE
;
5146 ssh
->packet_dispatch
[SSH1_SMSG_AGENT_OPEN
] = ssh1_smsg_agent_open
;
5150 if (conf_get_int(ssh
->conf
, CONF_x11_forward
) &&
5151 (ssh
->x11disp
= x11_setup_display(conf_get_str(ssh
->conf
, CONF_x11_display
),
5152 conf_get_int(ssh
->conf
, CONF_x11_auth
), ssh
->conf
))) {
5153 logevent("Requesting X11 forwarding");
5155 * Note that while we blank the X authentication data here, we don't
5156 * take any special action to blank the start of an X11 channel,
5157 * so using MIT-MAGIC-COOKIE-1 and actually opening an X connection
5158 * without having session blanking enabled is likely to leak your
5159 * cookie into the log.
5161 if (ssh
->v1_local_protoflags
& SSH1_PROTOFLAG_SCREEN_NUMBER
) {
5162 send_packet(ssh
, SSH1_CMSG_X11_REQUEST_FORWARDING
,
5163 PKT_STR
, ssh
->x11disp
->remoteauthprotoname
,
5165 PKT_STR
, ssh
->x11disp
->remoteauthdatastring
,
5167 PKT_INT
, ssh
->x11disp
->screennum
,
5170 send_packet(ssh
, SSH1_CMSG_X11_REQUEST_FORWARDING
,
5171 PKT_STR
, ssh
->x11disp
->remoteauthprotoname
,
5173 PKT_STR
, ssh
->x11disp
->remoteauthdatastring
,
5180 if (pktin
->type
!= SSH1_SMSG_SUCCESS
5181 && pktin
->type
!= SSH1_SMSG_FAILURE
) {
5182 bombout(("Protocol confusion"));
5184 } else if (pktin
->type
== SSH1_SMSG_FAILURE
) {
5185 logevent("X11 forwarding refused");
5187 logevent("X11 forwarding enabled");
5188 ssh
->X11_fwd_enabled
= TRUE
;
5189 ssh
->packet_dispatch
[SSH1_SMSG_X11_OPEN
] = ssh1_smsg_x11_open
;
5193 ssh_setup_portfwd(ssh
, ssh
->conf
);
5194 ssh
->packet_dispatch
[SSH1_MSG_PORT_OPEN
] = ssh1_msg_port_open
;
5196 if (!conf_get_int(ssh
->conf
, CONF_nopty
)) {
5198 /* Unpick the terminal-speed string. */
5199 /* XXX perhaps we should allow no speeds to be sent. */
5200 ssh
->ospeed
= 38400; ssh
->ispeed
= 38400; /* last-resort defaults */
5201 sscanf(conf_get_str(ssh
->conf
, CONF_termspeed
), "%d,%d", &ssh
->ospeed
, &ssh
->ispeed
);
5202 /* Send the pty request. */
5203 pkt
= ssh1_pkt_init(SSH1_CMSG_REQUEST_PTY
);
5204 ssh_pkt_addstring(pkt
, conf_get_str(ssh
->conf
, CONF_termtype
));
5205 ssh_pkt_adduint32(pkt
, ssh
->term_height
);
5206 ssh_pkt_adduint32(pkt
, ssh
->term_width
);
5207 ssh_pkt_adduint32(pkt
, 0); /* width in pixels */
5208 ssh_pkt_adduint32(pkt
, 0); /* height in pixels */
5209 parse_ttymodes(ssh
, ssh1_send_ttymode
, (void *)pkt
);
5210 ssh_pkt_addbyte(pkt
, SSH1_TTY_OP_ISPEED
);
5211 ssh_pkt_adduint32(pkt
, ssh
->ispeed
);
5212 ssh_pkt_addbyte(pkt
, SSH1_TTY_OP_OSPEED
);
5213 ssh_pkt_adduint32(pkt
, ssh
->ospeed
);
5214 ssh_pkt_addbyte(pkt
, SSH_TTY_OP_END
);
5216 ssh
->state
= SSH_STATE_INTERMED
;
5220 if (pktin
->type
!= SSH1_SMSG_SUCCESS
5221 && pktin
->type
!= SSH1_SMSG_FAILURE
) {
5222 bombout(("Protocol confusion"));
5224 } else if (pktin
->type
== SSH1_SMSG_FAILURE
) {
5225 c_write_str(ssh
, "Server refused to allocate pty\r\n");
5226 ssh
->editing
= ssh
->echoing
= 1;
5228 logeventf(ssh
, "Allocated pty (ospeed %dbps, ispeed %dbps)",
5229 ssh
->ospeed
, ssh
->ispeed
);
5230 ssh
->got_pty
= TRUE
;
5233 ssh
->editing
= ssh
->echoing
= 1;
5236 if (conf_get_int(ssh
->conf
, CONF_compression
)) {
5237 send_packet(ssh
, SSH1_CMSG_REQUEST_COMPRESSION
, PKT_INT
, 6, PKT_END
);
5241 if (pktin
->type
!= SSH1_SMSG_SUCCESS
5242 && pktin
->type
!= SSH1_SMSG_FAILURE
) {
5243 bombout(("Protocol confusion"));
5245 } else if (pktin
->type
== SSH1_SMSG_FAILURE
) {
5246 c_write_str(ssh
, "Server refused to compress\r\n");
5248 logevent("Started compression");
5249 ssh
->v1_compressing
= TRUE
;
5250 ssh
->cs_comp_ctx
= zlib_compress_init();
5251 logevent("Initialised zlib (RFC1950) compression");
5252 ssh
->sc_comp_ctx
= zlib_decompress_init();
5253 logevent("Initialised zlib (RFC1950) decompression");
5257 * Start the shell or command.
5259 * Special case: if the first-choice command is an SSH-2
5260 * subsystem (hence not usable here) and the second choice
5261 * exists, we fall straight back to that.
5264 char *cmd
= conf_get_str(ssh
->conf
, CONF_remote_cmd
);
5266 if (conf_get_int(ssh
->conf
, CONF_ssh_subsys
) &&
5267 conf_get_str(ssh
->conf
, CONF_remote_cmd2
)) {
5268 cmd
= conf_get_str(ssh
->conf
, CONF_remote_cmd2
);
5269 ssh
->fallback_cmd
= TRUE
;
5272 send_packet(ssh
, SSH1_CMSG_EXEC_CMD
, PKT_STR
, cmd
, PKT_END
);
5274 send_packet(ssh
, SSH1_CMSG_EXEC_SHELL
, PKT_END
);
5275 logevent("Started session");
5278 ssh
->state
= SSH_STATE_SESSION
;
5279 if (ssh
->size_needed
)
5280 ssh_size(ssh
, ssh
->term_width
, ssh
->term_height
);
5281 if (ssh
->eof_needed
)
5282 ssh_special(ssh
, TS_EOF
);
5285 ldisc_send(ssh
->ldisc
, NULL
, 0, 0);/* cause ldisc to notice changes */
5287 ssh
->channels
= newtree234(ssh_channelcmp
);
5291 * By this point, most incoming packets are already being
5292 * handled by the dispatch table, and we need only pay
5293 * attention to the unusual ones.
5298 if (pktin
->type
== SSH1_SMSG_SUCCESS
) {
5299 /* may be from EXEC_SHELL on some servers */
5300 } else if (pktin
->type
== SSH1_SMSG_FAILURE
) {
5301 /* may be from EXEC_SHELL on some servers
5302 * if no pty is available or in other odd cases. Ignore */
5304 bombout(("Strange packet received: type %d", pktin
->type
));
5309 int len
= min(inlen
, 512);
5310 send_packet(ssh
, SSH1_CMSG_STDIN_DATA
,
5311 PKT_INT
, len
, PKTT_DATA
, PKT_DATA
, in
, len
,
5312 PKTT_OTHER
, PKT_END
);
5323 * Handle the top-level SSH-2 protocol.
5325 static void ssh1_msg_debug(Ssh ssh
, struct Packet
*pktin
)
5330 ssh_pkt_getstring(pktin
, &msg
, &msglen
);
5331 logeventf(ssh
, "Remote debug message: %.*s", msglen
, msg
);
5334 static void ssh1_msg_disconnect(Ssh ssh
, struct Packet
*pktin
)
5336 /* log reason code in disconnect message */
5340 ssh_pkt_getstring(pktin
, &msg
, &msglen
);
5341 bombout(("Server sent disconnect message:\n\"%.*s\"", msglen
, msg
));
5344 static void ssh_msg_ignore(Ssh ssh
, struct Packet
*pktin
)
5346 /* Do nothing, because we're ignoring it! Duhh. */
5349 static void ssh1_protocol_setup(Ssh ssh
)
5354 * Most messages are handled by the coroutines.
5356 for (i
= 0; i
< 256; i
++)
5357 ssh
->packet_dispatch
[i
] = NULL
;
5360 * These special message types we install handlers for.
5362 ssh
->packet_dispatch
[SSH1_MSG_DISCONNECT
] = ssh1_msg_disconnect
;
5363 ssh
->packet_dispatch
[SSH1_MSG_IGNORE
] = ssh_msg_ignore
;
5364 ssh
->packet_dispatch
[SSH1_MSG_DEBUG
] = ssh1_msg_debug
;
5367 static void ssh1_protocol(Ssh ssh
, void *vin
, int inlen
,
5368 struct Packet
*pktin
)
5370 unsigned char *in
=(unsigned char*)vin
;
5371 if (ssh
->state
== SSH_STATE_CLOSED
)
5374 if (pktin
&& ssh
->packet_dispatch
[pktin
->type
]) {
5375 ssh
->packet_dispatch
[pktin
->type
](ssh
, pktin
);
5379 if (!ssh
->protocol_initial_phase_done
) {
5380 if (do_ssh1_login(ssh
, in
, inlen
, pktin
))
5381 ssh
->protocol_initial_phase_done
= TRUE
;
5386 do_ssh1_connection(ssh
, in
, inlen
, pktin
);
5390 * Utility routine for decoding comma-separated strings in KEXINIT.
5392 static int in_commasep_string(char *needle
, char *haystack
, int haylen
)
5395 if (!needle
|| !haystack
) /* protect against null pointers */
5397 needlen
= strlen(needle
);
5400 * Is it at the start of the string?
5402 if (haylen
>= needlen
&& /* haystack is long enough */
5403 !memcmp(needle
, haystack
, needlen
) && /* initial match */
5404 (haylen
== needlen
|| haystack
[needlen
] == ',')
5405 /* either , or EOS follows */
5409 * If not, search for the next comma and resume after that.
5410 * If no comma found, terminate.
5412 while (haylen
> 0 && *haystack
!= ',')
5413 haylen
--, haystack
++;
5416 haylen
--, haystack
++; /* skip over comma itself */
5421 * Similar routine for checking whether we have the first string in a list.
5423 static int first_in_commasep_string(char *needle
, char *haystack
, int haylen
)
5426 if (!needle
|| !haystack
) /* protect against null pointers */
5428 needlen
= strlen(needle
);
5430 * Is it at the start of the string?
5432 if (haylen
>= needlen
&& /* haystack is long enough */
5433 !memcmp(needle
, haystack
, needlen
) && /* initial match */
5434 (haylen
== needlen
|| haystack
[needlen
] == ',')
5435 /* either , or EOS follows */
5443 * SSH-2 key creation method.
5444 * (Currently assumes 2 lots of any hash are sufficient to generate
5445 * keys/IVs for any cipher/MAC. SSH2_MKKEY_ITERS documents this assumption.)
5447 #define SSH2_MKKEY_ITERS (2)
5448 static void ssh2_mkkey(Ssh ssh
, Bignum K
, unsigned char *H
, char chr
,
5449 unsigned char *keyspace
)
5451 const struct ssh_hash
*h
= ssh
->kex
->hash
;
5453 /* First hlen bytes. */
5455 if (!(ssh
->remote_bugs
& BUG_SSH2_DERIVEKEY
))
5456 hash_mpint(h
, s
, K
);
5457 h
->bytes(s
, H
, h
->hlen
);
5458 h
->bytes(s
, &chr
, 1);
5459 h
->bytes(s
, ssh
->v2_session_id
, ssh
->v2_session_id_len
);
5460 h
->final(s
, keyspace
);
5461 /* Next hlen bytes. */
5463 if (!(ssh
->remote_bugs
& BUG_SSH2_DERIVEKEY
))
5464 hash_mpint(h
, s
, K
);
5465 h
->bytes(s
, H
, h
->hlen
);
5466 h
->bytes(s
, keyspace
, h
->hlen
);
5467 h
->final(s
, keyspace
+ h
->hlen
);
5471 * Handle the SSH-2 transport layer.
5473 static int do_ssh2_transport(Ssh ssh
, void *vin
, int inlen
,
5474 struct Packet
*pktin
)
5476 unsigned char *in
= (unsigned char *)vin
;
5477 struct do_ssh2_transport_state
{
5478 int nbits
, pbits
, warn_kex
, warn_cscipher
, warn_sccipher
;
5479 Bignum p
, g
, e
, f
, K
;
5482 int kex_init_value
, kex_reply_value
;
5483 const struct ssh_mac
**maclist
;
5485 const struct ssh2_cipher
*cscipher_tobe
;
5486 const struct ssh2_cipher
*sccipher_tobe
;
5487 const struct ssh_mac
*csmac_tobe
;
5488 const struct ssh_mac
*scmac_tobe
;
5489 const struct ssh_compress
*cscomp_tobe
;
5490 const struct ssh_compress
*sccomp_tobe
;
5491 char *hostkeydata
, *sigdata
, *rsakeydata
, *keystr
, *fingerprint
;
5492 int hostkeylen
, siglen
, rsakeylen
;
5493 void *hkey
; /* actual host key */
5494 void *rsakey
; /* for RSA kex */
5495 unsigned char exchange_hash
[SSH2_KEX_MAX_HASH_LEN
];
5496 int n_preferred_kex
;
5497 const struct ssh_kexes
*preferred_kex
[KEX_MAX
];
5498 int n_preferred_ciphers
;
5499 const struct ssh2_ciphers
*preferred_ciphers
[CIPHER_MAX
];
5500 const struct ssh_compress
*preferred_comp
;
5501 int userauth_succeeded
; /* for delayed compression */
5502 int pending_compression
;
5503 int got_session_id
, activated_authconn
;
5504 struct Packet
*pktout
;
5509 crState(do_ssh2_transport_state
);
5511 crBegin(ssh
->do_ssh2_transport_crstate
);
5513 s
->cscipher_tobe
= s
->sccipher_tobe
= NULL
;
5514 s
->csmac_tobe
= s
->scmac_tobe
= NULL
;
5515 s
->cscomp_tobe
= s
->sccomp_tobe
= NULL
;
5517 s
->got_session_id
= s
->activated_authconn
= FALSE
;
5518 s
->userauth_succeeded
= FALSE
;
5519 s
->pending_compression
= FALSE
;
5522 * Be prepared to work around the buggy MAC problem.
5524 if (ssh
->remote_bugs
& BUG_SSH2_HMAC
)
5525 s
->maclist
= buggymacs
, s
->nmacs
= lenof(buggymacs
);
5527 s
->maclist
= macs
, s
->nmacs
= lenof(macs
);
5530 ssh
->pkt_kctx
= SSH2_PKTCTX_NOKEX
;
5532 int i
, j
, commalist_started
;
5535 * Set up the preferred key exchange. (NULL => warn below here)
5537 s
->n_preferred_kex
= 0;
5538 for (i
= 0; i
< KEX_MAX
; i
++) {
5539 switch (conf_get_int_int(ssh
->conf
, CONF_ssh_kexlist
, i
)) {
5541 s
->preferred_kex
[s
->n_preferred_kex
++] =
5542 &ssh_diffiehellman_gex
;
5545 s
->preferred_kex
[s
->n_preferred_kex
++] =
5546 &ssh_diffiehellman_group14
;
5549 s
->preferred_kex
[s
->n_preferred_kex
++] =
5550 &ssh_diffiehellman_group1
;
5553 s
->preferred_kex
[s
->n_preferred_kex
++] =
5557 /* Flag for later. Don't bother if it's the last in
5559 if (i
< KEX_MAX
- 1) {
5560 s
->preferred_kex
[s
->n_preferred_kex
++] = NULL
;
5567 * Set up the preferred ciphers. (NULL => warn below here)
5569 s
->n_preferred_ciphers
= 0;
5570 for (i
= 0; i
< CIPHER_MAX
; i
++) {
5571 switch (conf_get_int_int(ssh
->conf
, CONF_ssh_cipherlist
, i
)) {
5572 case CIPHER_BLOWFISH
:
5573 s
->preferred_ciphers
[s
->n_preferred_ciphers
++] = &ssh2_blowfish
;
5576 if (conf_get_int(ssh
->conf
, CONF_ssh2_des_cbc
)) {
5577 s
->preferred_ciphers
[s
->n_preferred_ciphers
++] = &ssh2_des
;
5581 s
->preferred_ciphers
[s
->n_preferred_ciphers
++] = &ssh2_3des
;
5584 s
->preferred_ciphers
[s
->n_preferred_ciphers
++] = &ssh2_aes
;
5586 case CIPHER_ARCFOUR
:
5587 s
->preferred_ciphers
[s
->n_preferred_ciphers
++] = &ssh2_arcfour
;
5590 /* Flag for later. Don't bother if it's the last in
5592 if (i
< CIPHER_MAX
- 1) {
5593 s
->preferred_ciphers
[s
->n_preferred_ciphers
++] = NULL
;
5600 * Set up preferred compression.
5602 if (conf_get_int(ssh
->conf
, CONF_compression
))
5603 s
->preferred_comp
= &ssh_zlib
;
5605 s
->preferred_comp
= &ssh_comp_none
;
5608 * Enable queueing of outgoing auth- or connection-layer
5609 * packets while we are in the middle of a key exchange.
5611 ssh
->queueing
= TRUE
;
5614 * Flag that KEX is in progress.
5616 ssh
->kex_in_progress
= TRUE
;
5619 * Construct and send our key exchange packet.
5621 s
->pktout
= ssh2_pkt_init(SSH2_MSG_KEXINIT
);
5622 for (i
= 0; i
< 16; i
++)
5623 ssh2_pkt_addbyte(s
->pktout
, (unsigned char) random_byte());
5624 /* List key exchange algorithms. */
5625 ssh2_pkt_addstring_start(s
->pktout
);
5626 commalist_started
= 0;
5627 for (i
= 0; i
< s
->n_preferred_kex
; i
++) {
5628 const struct ssh_kexes
*k
= s
->preferred_kex
[i
];
5629 if (!k
) continue; /* warning flag */
5630 for (j
= 0; j
< k
->nkexes
; j
++) {
5631 if (commalist_started
)
5632 ssh2_pkt_addstring_str(s
->pktout
, ",");
5633 ssh2_pkt_addstring_str(s
->pktout
, k
->list
[j
]->name
);
5634 commalist_started
= 1;
5637 /* List server host key algorithms. */
5638 ssh2_pkt_addstring_start(s
->pktout
);
5639 for (i
= 0; i
< lenof(hostkey_algs
); i
++) {
5640 ssh2_pkt_addstring_str(s
->pktout
, hostkey_algs
[i
]->name
);
5641 if (i
< lenof(hostkey_algs
) - 1)
5642 ssh2_pkt_addstring_str(s
->pktout
, ",");
5644 /* List client->server encryption algorithms. */
5645 ssh2_pkt_addstring_start(s
->pktout
);
5646 commalist_started
= 0;
5647 for (i
= 0; i
< s
->n_preferred_ciphers
; i
++) {
5648 const struct ssh2_ciphers
*c
= s
->preferred_ciphers
[i
];
5649 if (!c
) continue; /* warning flag */
5650 for (j
= 0; j
< c
->nciphers
; j
++) {
5651 if (commalist_started
)
5652 ssh2_pkt_addstring_str(s
->pktout
, ",");
5653 ssh2_pkt_addstring_str(s
->pktout
, c
->list
[j
]->name
);
5654 commalist_started
= 1;
5657 /* List server->client encryption algorithms. */
5658 ssh2_pkt_addstring_start(s
->pktout
);
5659 commalist_started
= 0;
5660 for (i
= 0; i
< s
->n_preferred_ciphers
; i
++) {
5661 const struct ssh2_ciphers
*c
= s
->preferred_ciphers
[i
];
5662 if (!c
) continue; /* warning flag */
5663 for (j
= 0; j
< c
->nciphers
; j
++) {
5664 if (commalist_started
)
5665 ssh2_pkt_addstring_str(s
->pktout
, ",");
5666 ssh2_pkt_addstring_str(s
->pktout
, c
->list
[j
]->name
);
5667 commalist_started
= 1;
5670 /* List client->server MAC algorithms. */
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
, ",");
5677 /* List server->client MAC algorithms. */
5678 ssh2_pkt_addstring_start(s
->pktout
);
5679 for (i
= 0; i
< s
->nmacs
; i
++) {
5680 ssh2_pkt_addstring_str(s
->pktout
, s
->maclist
[i
]->name
);
5681 if (i
< s
->nmacs
- 1)
5682 ssh2_pkt_addstring_str(s
->pktout
, ",");
5684 /* List client->server compression algorithms,
5685 * then server->client compression algorithms. (We use the
5686 * same set twice.) */
5687 for (j
= 0; j
< 2; j
++) {
5688 ssh2_pkt_addstring_start(s
->pktout
);
5689 assert(lenof(compressions
) > 1);
5690 /* Prefer non-delayed versions */
5691 ssh2_pkt_addstring_str(s
->pktout
, s
->preferred_comp
->name
);
5692 /* We don't even list delayed versions of algorithms until
5693 * they're allowed to be used, to avoid a race. See the end of
5695 if (s
->userauth_succeeded
&& s
->preferred_comp
->delayed_name
) {
5696 ssh2_pkt_addstring_str(s
->pktout
, ",");
5697 ssh2_pkt_addstring_str(s
->pktout
,
5698 s
->preferred_comp
->delayed_name
);
5700 for (i
= 0; i
< lenof(compressions
); i
++) {
5701 const struct ssh_compress
*c
= compressions
[i
];
5702 if (c
!= s
->preferred_comp
) {
5703 ssh2_pkt_addstring_str(s
->pktout
, ",");
5704 ssh2_pkt_addstring_str(s
->pktout
, c
->name
);
5705 if (s
->userauth_succeeded
&& c
->delayed_name
) {
5706 ssh2_pkt_addstring_str(s
->pktout
, ",");
5707 ssh2_pkt_addstring_str(s
->pktout
, c
->delayed_name
);
5712 /* List client->server languages. Empty list. */
5713 ssh2_pkt_addstring_start(s
->pktout
);
5714 /* List server->client languages. Empty list. */
5715 ssh2_pkt_addstring_start(s
->pktout
);
5716 /* First KEX packet does _not_ follow, because we're not that brave. */
5717 ssh2_pkt_addbool(s
->pktout
, FALSE
);
5719 ssh2_pkt_adduint32(s
->pktout
, 0);
5722 s
->our_kexinitlen
= s
->pktout
->length
- 5;
5723 s
->our_kexinit
= snewn(s
->our_kexinitlen
, unsigned char);
5724 memcpy(s
->our_kexinit
, s
->pktout
->data
+ 5, s
->our_kexinitlen
);
5726 ssh2_pkt_send_noqueue(ssh
, s
->pktout
);
5732 * Now examine the other side's KEXINIT to see what we're up
5736 char *str
, *preferred
;
5739 if (pktin
->type
!= SSH2_MSG_KEXINIT
) {
5740 bombout(("expected key exchange packet from server"));
5744 ssh
->hostkey
= NULL
;
5745 s
->cscipher_tobe
= NULL
;
5746 s
->sccipher_tobe
= NULL
;
5747 s
->csmac_tobe
= NULL
;
5748 s
->scmac_tobe
= NULL
;
5749 s
->cscomp_tobe
= NULL
;
5750 s
->sccomp_tobe
= NULL
;
5751 s
->warn_kex
= s
->warn_cscipher
= s
->warn_sccipher
= FALSE
;
5753 pktin
->savedpos
+= 16; /* skip garbage cookie */
5754 ssh_pkt_getstring(pktin
, &str
, &len
); /* key exchange algorithms */
5757 for (i
= 0; i
< s
->n_preferred_kex
; i
++) {
5758 const struct ssh_kexes
*k
= s
->preferred_kex
[i
];
5762 for (j
= 0; j
< k
->nkexes
; j
++) {
5763 if (!preferred
) preferred
= k
->list
[j
]->name
;
5764 if (in_commasep_string(k
->list
[j
]->name
, str
, len
)) {
5765 ssh
->kex
= k
->list
[j
];
5774 bombout(("Couldn't agree a key exchange algorithm (available: %s)",
5775 str ? str
: "(null)"));
5779 * Note that the server's guess is considered wrong if it doesn't match
5780 * the first algorithm in our list, even if it's still the algorithm
5783 s
->guessok
= first_in_commasep_string(preferred
, str
, len
);
5784 ssh_pkt_getstring(pktin
, &str
, &len
); /* host key algorithms */
5785 for (i
= 0; i
< lenof(hostkey_algs
); i
++) {
5786 if (in_commasep_string(hostkey_algs
[i
]->name
, str
, len
)) {
5787 ssh
->hostkey
= hostkey_algs
[i
];
5791 if (!ssh
->hostkey
) {
5792 bombout(("Couldn't agree a host key algorithm (available: %s)",
5793 str ? str
: "(null)"));
5797 s
->guessok
= s
->guessok
&&
5798 first_in_commasep_string(hostkey_algs
[0]->name
, str
, len
);
5799 ssh_pkt_getstring(pktin
, &str
, &len
); /* client->server cipher */
5800 for (i
= 0; i
< s
->n_preferred_ciphers
; i
++) {
5801 const struct ssh2_ciphers
*c
= s
->preferred_ciphers
[i
];
5803 s
->warn_cscipher
= TRUE
;
5805 for (j
= 0; j
< c
->nciphers
; j
++) {
5806 if (in_commasep_string(c
->list
[j
]->name
, str
, len
)) {
5807 s
->cscipher_tobe
= c
->list
[j
];
5812 if (s
->cscipher_tobe
)
5815 if (!s
->cscipher_tobe
) {
5816 bombout(("Couldn't agree a client-to-server cipher (available: %s)",
5817 str ? str
: "(null)"));
5821 ssh_pkt_getstring(pktin
, &str
, &len
); /* server->client cipher */
5822 for (i
= 0; i
< s
->n_preferred_ciphers
; i
++) {
5823 const struct ssh2_ciphers
*c
= s
->preferred_ciphers
[i
];
5825 s
->warn_sccipher
= TRUE
;
5827 for (j
= 0; j
< c
->nciphers
; j
++) {
5828 if (in_commasep_string(c
->list
[j
]->name
, str
, len
)) {
5829 s
->sccipher_tobe
= c
->list
[j
];
5834 if (s
->sccipher_tobe
)
5837 if (!s
->sccipher_tobe
) {
5838 bombout(("Couldn't agree a server-to-client cipher (available: %s)",
5839 str ? str
: "(null)"));
5843 ssh_pkt_getstring(pktin
, &str
, &len
); /* client->server mac */
5844 for (i
= 0; i
< s
->nmacs
; i
++) {
5845 if (in_commasep_string(s
->maclist
[i
]->name
, str
, len
)) {
5846 s
->csmac_tobe
= s
->maclist
[i
];
5850 ssh_pkt_getstring(pktin
, &str
, &len
); /* server->client mac */
5851 for (i
= 0; i
< s
->nmacs
; i
++) {
5852 if (in_commasep_string(s
->maclist
[i
]->name
, str
, len
)) {
5853 s
->scmac_tobe
= s
->maclist
[i
];
5857 ssh_pkt_getstring(pktin
, &str
, &len
); /* client->server compression */
5858 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
5859 const struct ssh_compress
*c
=
5860 i
== 0 ? s
->preferred_comp
: compressions
[i
- 1];
5861 if (in_commasep_string(c
->name
, str
, len
)) {
5864 } else if (in_commasep_string(c
->delayed_name
, str
, len
)) {
5865 if (s
->userauth_succeeded
) {
5869 s
->pending_compression
= TRUE
; /* try this later */
5873 ssh_pkt_getstring(pktin
, &str
, &len
); /* server->client compression */
5874 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
5875 const struct ssh_compress
*c
=
5876 i
== 0 ? s
->preferred_comp
: compressions
[i
- 1];
5877 if (in_commasep_string(c
->name
, str
, len
)) {
5880 } else if (in_commasep_string(c
->delayed_name
, str
, len
)) {
5881 if (s
->userauth_succeeded
) {
5885 s
->pending_compression
= TRUE
; /* try this later */
5889 if (s
->pending_compression
) {
5890 logevent("Server supports delayed compression; "
5891 "will try this later");
5893 ssh_pkt_getstring(pktin
, &str
, &len
); /* client->server language */
5894 ssh_pkt_getstring(pktin
, &str
, &len
); /* server->client language */
5895 s
->ignorepkt
= ssh2_pkt_getbool(pktin
) && !s
->guessok
;
5898 ssh_set_frozen(ssh
, 1);
5899 s
->dlgret
= askalg(ssh
->frontend
, "key-exchange algorithm",
5901 ssh_dialog_callback
, ssh
);
5902 if (s
->dlgret
< 0) {
5906 bombout(("Unexpected data from server while"
5907 " waiting for user response"));
5910 } while (pktin
|| inlen
> 0);
5911 s
->dlgret
= ssh
->user_response
;
5913 ssh_set_frozen(ssh
, 0);
5914 if (s
->dlgret
== 0) {
5915 ssh_disconnect(ssh
, "User aborted at kex warning", NULL
,
5921 if (s
->warn_cscipher
) {
5922 ssh_set_frozen(ssh
, 1);
5923 s
->dlgret
= askalg(ssh
->frontend
,
5924 "client-to-server cipher",
5925 s
->cscipher_tobe
->name
,
5926 ssh_dialog_callback
, ssh
);
5927 if (s
->dlgret
< 0) {
5931 bombout(("Unexpected data from server while"
5932 " waiting for user response"));
5935 } while (pktin
|| inlen
> 0);
5936 s
->dlgret
= ssh
->user_response
;
5938 ssh_set_frozen(ssh
, 0);
5939 if (s
->dlgret
== 0) {
5940 ssh_disconnect(ssh
, "User aborted at cipher warning", NULL
,
5946 if (s
->warn_sccipher
) {
5947 ssh_set_frozen(ssh
, 1);
5948 s
->dlgret
= askalg(ssh
->frontend
,
5949 "server-to-client cipher",
5950 s
->sccipher_tobe
->name
,
5951 ssh_dialog_callback
, ssh
);
5952 if (s
->dlgret
< 0) {
5956 bombout(("Unexpected data from server while"
5957 " waiting for user response"));
5960 } while (pktin
|| inlen
> 0);
5961 s
->dlgret
= ssh
->user_response
;
5963 ssh_set_frozen(ssh
, 0);
5964 if (s
->dlgret
== 0) {
5965 ssh_disconnect(ssh
, "User aborted at cipher warning", NULL
,
5971 ssh
->exhash
= ssh
->kex
->hash
->init();
5972 hash_string(ssh
->kex
->hash
, ssh
->exhash
, ssh
->v_c
, strlen(ssh
->v_c
));
5973 hash_string(ssh
->kex
->hash
, ssh
->exhash
, ssh
->v_s
, strlen(ssh
->v_s
));
5974 hash_string(ssh
->kex
->hash
, ssh
->exhash
,
5975 s
->our_kexinit
, s
->our_kexinitlen
);
5976 sfree(s
->our_kexinit
);
5977 if (pktin
->length
> 5)
5978 hash_string(ssh
->kex
->hash
, ssh
->exhash
,
5979 pktin
->data
+ 5, pktin
->length
- 5);
5981 if (s
->ignorepkt
) /* first_kex_packet_follows */
5982 crWaitUntil(pktin
); /* Ignore packet */
5985 if (ssh
->kex
->main_type
== KEXTYPE_DH
) {
5987 * Work out the number of bits of key we will need from the
5988 * key exchange. We start with the maximum key length of
5994 csbits
= s
->cscipher_tobe
->keylen
;
5995 scbits
= s
->sccipher_tobe
->keylen
;
5996 s
->nbits
= (csbits
> scbits ? csbits
: scbits
);
5998 /* The keys only have hlen-bit entropy, since they're based on
5999 * a hash. So cap the key size at hlen bits. */
6000 if (s
->nbits
> ssh
->kex
->hash
->hlen
* 8)
6001 s
->nbits
= ssh
->kex
->hash
->hlen
* 8;
6004 * If we're doing Diffie-Hellman group exchange, start by
6005 * requesting a group.
6007 if (!ssh
->kex
->pdata
) {
6008 logevent("Doing Diffie-Hellman group exchange");
6009 ssh
->pkt_kctx
= SSH2_PKTCTX_DHGEX
;
6011 * Work out how big a DH group we will need to allow that
6014 s
->pbits
= 512 << ((s
->nbits
- 1) / 64);
6015 s
->pktout
= ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST
);
6016 ssh2_pkt_adduint32(s
->pktout
, s
->pbits
);
6017 ssh2_pkt_send_noqueue(ssh
, s
->pktout
);
6020 if (pktin
->type
!= SSH2_MSG_KEX_DH_GEX_GROUP
) {
6021 bombout(("expected key exchange group packet from server"));
6024 s
->p
= ssh2_pkt_getmp(pktin
);
6025 s
->g
= ssh2_pkt_getmp(pktin
);
6026 if (!s
->p
|| !s
->g
) {
6027 bombout(("unable to read mp-ints from incoming group packet"));
6030 ssh
->kex_ctx
= dh_setup_gex(s
->p
, s
->g
);
6031 s
->kex_init_value
= SSH2_MSG_KEX_DH_GEX_INIT
;
6032 s
->kex_reply_value
= SSH2_MSG_KEX_DH_GEX_REPLY
;
6034 ssh
->pkt_kctx
= SSH2_PKTCTX_DHGROUP
;
6035 ssh
->kex_ctx
= dh_setup_group(ssh
->kex
);
6036 s
->kex_init_value
= SSH2_MSG_KEXDH_INIT
;
6037 s
->kex_reply_value
= SSH2_MSG_KEXDH_REPLY
;
6038 logeventf(ssh
, "Using Diffie-Hellman with standard group \"%s\"",
6039 ssh
->kex
->groupname
);
6042 logeventf(ssh
, "Doing Diffie-Hellman key exchange with hash %s",
6043 ssh
->kex
->hash
->text_name
);
6045 * Now generate and send e for Diffie-Hellman.
6047 set_busy_status(ssh
->frontend
, BUSY_CPU
); /* this can take a while */
6048 s
->e
= dh_create_e(ssh
->kex_ctx
, s
->nbits
* 2);
6049 s
->pktout
= ssh2_pkt_init(s
->kex_init_value
);
6050 ssh2_pkt_addmp(s
->pktout
, s
->e
);
6051 ssh2_pkt_send_noqueue(ssh
, s
->pktout
);
6053 set_busy_status(ssh
->frontend
, BUSY_WAITING
); /* wait for server */
6055 if (pktin
->type
!= s
->kex_reply_value
) {
6056 bombout(("expected key exchange reply packet from server"));
6059 set_busy_status(ssh
->frontend
, BUSY_CPU
); /* cogitate */
6060 ssh_pkt_getstring(pktin
, &s
->hostkeydata
, &s
->hostkeylen
);
6061 s
->hkey
= ssh
->hostkey
->newkey(s
->hostkeydata
, s
->hostkeylen
);
6062 s
->f
= ssh2_pkt_getmp(pktin
);
6064 bombout(("unable to parse key exchange reply packet"));
6067 ssh_pkt_getstring(pktin
, &s
->sigdata
, &s
->siglen
);
6069 s
->K
= dh_find_K(ssh
->kex_ctx
, s
->f
);
6071 /* We assume everything from now on will be quick, and it might
6072 * involve user interaction. */
6073 set_busy_status(ssh
->frontend
, BUSY_NOT
);
6075 hash_string(ssh
->kex
->hash
, ssh
->exhash
, s
->hostkeydata
, s
->hostkeylen
);
6076 if (!ssh
->kex
->pdata
) {
6077 hash_uint32(ssh
->kex
->hash
, ssh
->exhash
, s
->pbits
);
6078 hash_mpint(ssh
->kex
->hash
, ssh
->exhash
, s
->p
);
6079 hash_mpint(ssh
->kex
->hash
, ssh
->exhash
, s
->g
);
6081 hash_mpint(ssh
->kex
->hash
, ssh
->exhash
, s
->e
);
6082 hash_mpint(ssh
->kex
->hash
, ssh
->exhash
, s
->f
);
6084 dh_cleanup(ssh
->kex_ctx
);
6086 if (!ssh
->kex
->pdata
) {
6091 logeventf(ssh
, "Doing RSA key exchange with hash %s",
6092 ssh
->kex
->hash
->text_name
);
6093 ssh
->pkt_kctx
= SSH2_PKTCTX_RSAKEX
;
6095 * RSA key exchange. First expect a KEXRSA_PUBKEY packet
6099 if (pktin
->type
!= SSH2_MSG_KEXRSA_PUBKEY
) {
6100 bombout(("expected RSA public key packet from server"));
6104 ssh_pkt_getstring(pktin
, &s
->hostkeydata
, &s
->hostkeylen
);
6105 hash_string(ssh
->kex
->hash
, ssh
->exhash
,
6106 s
->hostkeydata
, s
->hostkeylen
);
6107 s
->hkey
= ssh
->hostkey
->newkey(s
->hostkeydata
, s
->hostkeylen
);
6111 ssh_pkt_getstring(pktin
, &keydata
, &s
->rsakeylen
);
6112 s
->rsakeydata
= snewn(s
->rsakeylen
, char);
6113 memcpy(s
->rsakeydata
, keydata
, s
->rsakeylen
);
6116 s
->rsakey
= ssh_rsakex_newkey(s
->rsakeydata
, s
->rsakeylen
);
6118 sfree(s
->rsakeydata
);
6119 bombout(("unable to parse RSA public key from server"));
6123 hash_string(ssh
->kex
->hash
, ssh
->exhash
, s
->rsakeydata
, s
->rsakeylen
);
6126 * Next, set up a shared secret K, of precisely KLEN -
6127 * 2*HLEN - 49 bits, where KLEN is the bit length of the
6128 * RSA key modulus and HLEN is the bit length of the hash
6132 int klen
= ssh_rsakex_klen(s
->rsakey
);
6133 int nbits
= klen
- (2*ssh
->kex
->hash
->hlen
*8 + 49);
6135 unsigned char *kstr1
, *kstr2
, *outstr
;
6136 int kstr1len
, kstr2len
, outstrlen
;
6138 s
->K
= bn_power_2(nbits
- 1);
6140 for (i
= 0; i
< nbits
; i
++) {
6142 byte
= random_byte();
6144 bignum_set_bit(s
->K
, i
, (byte
>> (i
& 7)) & 1);
6148 * Encode this as an mpint.
6150 kstr1
= ssh2_mpint_fmt(s
->K
, &kstr1len
);
6151 kstr2
= snewn(kstr2len
= 4 + kstr1len
, unsigned char);
6152 PUT_32BIT(kstr2
, kstr1len
);
6153 memcpy(kstr2
+ 4, kstr1
, kstr1len
);
6156 * Encrypt it with the given RSA key.
6158 outstrlen
= (klen
+ 7) / 8;
6159 outstr
= snewn(outstrlen
, unsigned char);
6160 ssh_rsakex_encrypt(ssh
->kex
->hash
, kstr2
, kstr2len
,
6161 outstr
, outstrlen
, s
->rsakey
);
6164 * And send it off in a return packet.
6166 s
->pktout
= ssh2_pkt_init(SSH2_MSG_KEXRSA_SECRET
);
6167 ssh2_pkt_addstring_start(s
->pktout
);
6168 ssh2_pkt_addstring_data(s
->pktout
, (char *)outstr
, outstrlen
);
6169 ssh2_pkt_send_noqueue(ssh
, s
->pktout
);
6171 hash_string(ssh
->kex
->hash
, ssh
->exhash
, outstr
, outstrlen
);
6178 ssh_rsakex_freekey(s
->rsakey
);
6181 if (pktin
->type
!= SSH2_MSG_KEXRSA_DONE
) {
6182 sfree(s
->rsakeydata
);
6183 bombout(("expected signature packet from server"));
6187 ssh_pkt_getstring(pktin
, &s
->sigdata
, &s
->siglen
);
6189 sfree(s
->rsakeydata
);
6192 hash_mpint(ssh
->kex
->hash
, ssh
->exhash
, s
->K
);
6193 assert(ssh
->kex
->hash
->hlen
<= sizeof(s
->exchange_hash
));
6194 ssh
->kex
->hash
->final(ssh
->exhash
, s
->exchange_hash
);
6196 ssh
->kex_ctx
= NULL
;
6199 debug(("Exchange hash is:\n"));
6200 dmemdump(s
->exchange_hash
, ssh
->kex
->hash
->hlen
);
6204 !ssh
->hostkey
->verifysig(s
->hkey
, s
->sigdata
, s
->siglen
,
6205 (char *)s
->exchange_hash
,
6206 ssh
->kex
->hash
->hlen
)) {
6207 bombout(("Server's host key did not match the signature supplied"));
6212 * Authenticate remote host: verify host key. (We've already
6213 * checked the signature of the exchange hash.)
6215 s
->keystr
= ssh
->hostkey
->fmtkey(s
->hkey
);
6216 s
->fingerprint
= ssh
->hostkey
->fingerprint(s
->hkey
);
6217 ssh_set_frozen(ssh
, 1);
6218 s
->dlgret
= verify_ssh_host_key(ssh
->frontend
,
6219 ssh
->savedhost
, ssh
->savedport
,
6220 ssh
->hostkey
->keytype
, s
->keystr
,
6222 ssh_dialog_callback
, ssh
);
6223 if (s
->dlgret
< 0) {
6227 bombout(("Unexpected data from server while waiting"
6228 " for user host key response"));
6231 } while (pktin
|| inlen
> 0);
6232 s
->dlgret
= ssh
->user_response
;
6234 ssh_set_frozen(ssh
, 0);
6235 if (s
->dlgret
== 0) {
6236 ssh_disconnect(ssh
, "User aborted at host key verification", NULL
,
6240 if (!s
->got_session_id
) { /* don't bother logging this in rekeys */
6241 logevent("Host key fingerprint is:");
6242 logevent(s
->fingerprint
);
6244 sfree(s
->fingerprint
);
6246 ssh
->hostkey
->freekey(s
->hkey
);
6249 * The exchange hash from the very first key exchange is also
6250 * the session id, used in session key construction and
6253 if (!s
->got_session_id
) {
6254 assert(sizeof(s
->exchange_hash
) <= sizeof(ssh
->v2_session_id
));
6255 memcpy(ssh
->v2_session_id
, s
->exchange_hash
,
6256 sizeof(s
->exchange_hash
));
6257 ssh
->v2_session_id_len
= ssh
->kex
->hash
->hlen
;
6258 assert(ssh
->v2_session_id_len
<= sizeof(ssh
->v2_session_id
));
6259 s
->got_session_id
= TRUE
;
6263 * Send SSH2_MSG_NEWKEYS.
6265 s
->pktout
= ssh2_pkt_init(SSH2_MSG_NEWKEYS
);
6266 ssh2_pkt_send_noqueue(ssh
, s
->pktout
);
6267 ssh
->outgoing_data_size
= 0; /* start counting from here */
6270 * We've sent client NEWKEYS, so create and initialise
6271 * client-to-server session keys.
6273 if (ssh
->cs_cipher_ctx
)
6274 ssh
->cscipher
->free_context(ssh
->cs_cipher_ctx
);
6275 ssh
->cscipher
= s
->cscipher_tobe
;
6276 ssh
->cs_cipher_ctx
= ssh
->cscipher
->make_context();
6278 if (ssh
->cs_mac_ctx
)
6279 ssh
->csmac
->free_context(ssh
->cs_mac_ctx
);
6280 ssh
->csmac
= s
->csmac_tobe
;
6281 ssh
->cs_mac_ctx
= ssh
->csmac
->make_context();
6283 if (ssh
->cs_comp_ctx
)
6284 ssh
->cscomp
->compress_cleanup(ssh
->cs_comp_ctx
);
6285 ssh
->cscomp
= s
->cscomp_tobe
;
6286 ssh
->cs_comp_ctx
= ssh
->cscomp
->compress_init();
6289 * Set IVs on client-to-server keys. Here we use the exchange
6290 * hash from the _first_ key exchange.
6293 unsigned char keyspace
[SSH2_KEX_MAX_HASH_LEN
* SSH2_MKKEY_ITERS
];
6294 assert(sizeof(keyspace
) >= ssh
->kex
->hash
->hlen
* SSH2_MKKEY_ITERS
);
6295 ssh2_mkkey(ssh
,s
->K
,s
->exchange_hash
,'C',keyspace
);
6296 assert((ssh
->cscipher
->keylen
+7) / 8 <=
6297 ssh
->kex
->hash
->hlen
* SSH2_MKKEY_ITERS
);
6298 ssh
->cscipher
->setkey(ssh
->cs_cipher_ctx
, keyspace
);
6299 ssh2_mkkey(ssh
,s
->K
,s
->exchange_hash
,'A',keyspace
);
6300 assert(ssh
->cscipher
->blksize
<=
6301 ssh
->kex
->hash
->hlen
* SSH2_MKKEY_ITERS
);
6302 ssh
->cscipher
->setiv(ssh
->cs_cipher_ctx
, keyspace
);
6303 ssh2_mkkey(ssh
,s
->K
,s
->exchange_hash
,'E',keyspace
);
6304 assert(ssh
->csmac
->len
<=
6305 ssh
->kex
->hash
->hlen
* SSH2_MKKEY_ITERS
);
6306 ssh
->csmac
->setkey(ssh
->cs_mac_ctx
, keyspace
);
6307 smemclr(keyspace
, sizeof(keyspace
));
6310 logeventf(ssh
, "Initialised %.200s client->server encryption",
6311 ssh
->cscipher
->text_name
);
6312 logeventf(ssh
, "Initialised %.200s client->server MAC algorithm",
6313 ssh
->csmac
->text_name
);
6314 if (ssh
->cscomp
->text_name
)
6315 logeventf(ssh
, "Initialised %s compression",
6316 ssh
->cscomp
->text_name
);
6319 * Now our end of the key exchange is complete, we can send all
6320 * our queued higher-layer packets.
6322 ssh
->queueing
= FALSE
;
6323 ssh2_pkt_queuesend(ssh
);
6326 * Expect SSH2_MSG_NEWKEYS from server.
6329 if (pktin
->type
!= SSH2_MSG_NEWKEYS
) {
6330 bombout(("expected new-keys packet from server"));
6333 ssh
->incoming_data_size
= 0; /* start counting from here */
6336 * We've seen server NEWKEYS, so create and initialise
6337 * server-to-client session keys.
6339 if (ssh
->sc_cipher_ctx
)
6340 ssh
->sccipher
->free_context(ssh
->sc_cipher_ctx
);
6341 ssh
->sccipher
= s
->sccipher_tobe
;
6342 ssh
->sc_cipher_ctx
= ssh
->sccipher
->make_context();
6344 if (ssh
->sc_mac_ctx
)
6345 ssh
->scmac
->free_context(ssh
->sc_mac_ctx
);
6346 ssh
->scmac
= s
->scmac_tobe
;
6347 ssh
->sc_mac_ctx
= ssh
->scmac
->make_context();
6349 if (ssh
->sc_comp_ctx
)
6350 ssh
->sccomp
->decompress_cleanup(ssh
->sc_comp_ctx
);
6351 ssh
->sccomp
= s
->sccomp_tobe
;
6352 ssh
->sc_comp_ctx
= ssh
->sccomp
->decompress_init();
6355 * Set IVs on server-to-client keys. Here we use the exchange
6356 * hash from the _first_ key exchange.
6359 unsigned char keyspace
[SSH2_KEX_MAX_HASH_LEN
* SSH2_MKKEY_ITERS
];
6360 assert(sizeof(keyspace
) >= ssh
->kex
->hash
->hlen
* SSH2_MKKEY_ITERS
);
6361 ssh2_mkkey(ssh
,s
->K
,s
->exchange_hash
,'D',keyspace
);
6362 assert((ssh
->sccipher
->keylen
+7) / 8 <=
6363 ssh
->kex
->hash
->hlen
* SSH2_MKKEY_ITERS
);
6364 ssh
->sccipher
->setkey(ssh
->sc_cipher_ctx
, keyspace
);
6365 ssh2_mkkey(ssh
,s
->K
,s
->exchange_hash
,'B',keyspace
);
6366 assert(ssh
->sccipher
->blksize
<=
6367 ssh
->kex
->hash
->hlen
* SSH2_MKKEY_ITERS
);
6368 ssh
->sccipher
->setiv(ssh
->sc_cipher_ctx
, keyspace
);
6369 ssh2_mkkey(ssh
,s
->K
,s
->exchange_hash
,'F',keyspace
);
6370 assert(ssh
->scmac
->len
<=
6371 ssh
->kex
->hash
->hlen
* SSH2_MKKEY_ITERS
);
6372 ssh
->scmac
->setkey(ssh
->sc_mac_ctx
, keyspace
);
6373 smemclr(keyspace
, sizeof(keyspace
));
6375 logeventf(ssh
, "Initialised %.200s server->client encryption",
6376 ssh
->sccipher
->text_name
);
6377 logeventf(ssh
, "Initialised %.200s server->client MAC algorithm",
6378 ssh
->scmac
->text_name
);
6379 if (ssh
->sccomp
->text_name
)
6380 logeventf(ssh
, "Initialised %s decompression",
6381 ssh
->sccomp
->text_name
);
6384 * Free shared secret.
6389 * Key exchange is over. Loop straight back round if we have a
6390 * deferred rekey reason.
6392 if (ssh
->deferred_rekey_reason
) {
6393 logevent(ssh
->deferred_rekey_reason
);
6395 ssh
->deferred_rekey_reason
= NULL
;
6396 goto begin_key_exchange
;
6400 * Otherwise, schedule a timer for our next rekey.
6402 ssh
->kex_in_progress
= FALSE
;
6403 ssh
->last_rekey
= GETTICKCOUNT();
6404 if (conf_get_int(ssh
->conf
, CONF_ssh_rekey_time
) != 0)
6405 ssh
->next_rekey
= schedule_timer(conf_get_int(ssh
->conf
, CONF_ssh_rekey_time
)*60*TICKSPERSEC
,
6409 * If this is the first key exchange phase, we must pass the
6410 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
6411 * wants to see it but because it will need time to initialise
6412 * itself before it sees an actual packet. In subsequent key
6413 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
6414 * it would only confuse the layer above.
6416 if (s
->activated_authconn
) {
6419 s
->activated_authconn
= TRUE
;
6422 * Now we're encrypting. Begin returning 1 to the protocol main
6423 * function so that other things can run on top of the
6424 * transport. If we ever see a KEXINIT, we must go back to the
6427 * We _also_ go back to the start if we see pktin==NULL and
6428 * inlen negative, because this is a special signal meaning
6429 * `initiate client-driven rekey', and `in' contains a message
6430 * giving the reason for the rekey.
6432 * inlen==-1 means always initiate a rekey;
6433 * inlen==-2 means that userauth has completed successfully and
6434 * we should consider rekeying (for delayed compression).
6436 while (!((pktin
&& pktin
->type
== SSH2_MSG_KEXINIT
) ||
6437 (!pktin
&& inlen
< 0))) {
6442 logevent("Server initiated key re-exchange");
6446 * authconn has seen a USERAUTH_SUCCEEDED. Time to enable
6447 * delayed compression, if it's available.
6449 * draft-miller-secsh-compression-delayed-00 says that you
6450 * negotiate delayed compression in the first key exchange, and
6451 * both sides start compressing when the server has sent
6452 * USERAUTH_SUCCESS. This has a race condition -- the server
6453 * can't know when the client has seen it, and thus which incoming
6454 * packets it should treat as compressed.
6456 * Instead, we do the initial key exchange without offering the
6457 * delayed methods, but note if the server offers them; when we
6458 * get here, if a delayed method was available that was higher
6459 * on our list than what we got, we initiate a rekey in which we
6460 * _do_ list the delayed methods (and hopefully get it as a
6461 * result). Subsequent rekeys will do the same.
6463 assert(!s
->userauth_succeeded
); /* should only happen once */
6464 s
->userauth_succeeded
= TRUE
;
6465 if (!s
->pending_compression
)
6466 /* Can't see any point rekeying. */
6467 goto wait_for_rekey
; /* this is utterly horrid */
6468 /* else fall through to rekey... */
6469 s
->pending_compression
= FALSE
;
6472 * Now we've decided to rekey.
6474 * Special case: if the server bug is set that doesn't
6475 * allow rekeying, we give a different log message and
6476 * continue waiting. (If such a server _initiates_ a rekey,
6477 * we process it anyway!)
6479 if ((ssh
->remote_bugs
& BUG_SSH2_REKEY
)) {
6480 logeventf(ssh
, "Server bug prevents key re-exchange (%s)",
6482 /* Reset the counters, so that at least this message doesn't
6483 * hit the event log _too_ often. */
6484 ssh
->outgoing_data_size
= 0;
6485 ssh
->incoming_data_size
= 0;
6486 if (conf_get_int(ssh
->conf
, CONF_ssh_rekey_time
) != 0) {
6488 schedule_timer(conf_get_int(ssh
->conf
, CONF_ssh_rekey_time
)*60*TICKSPERSEC
,
6491 goto wait_for_rekey
; /* this is still utterly horrid */
6493 logeventf(ssh
, "Initiating key re-exchange (%s)", (char *)in
);
6496 goto begin_key_exchange
;
6502 * Add data to an SSH-2 channel output buffer.
6504 static void ssh2_add_channel_data(struct ssh_channel
*c
, char *buf
,
6507 bufchain_add(&c
->v
.v2
.outbuffer
, buf
, len
);
6511 * Attempt to send data on an SSH-2 channel.
6513 static int ssh2_try_send(struct ssh_channel
*c
)
6516 struct Packet
*pktout
;
6519 while (c
->v
.v2
.remwindow
> 0 && bufchain_size(&c
->v
.v2
.outbuffer
) > 0) {
6522 bufchain_prefix(&c
->v
.v2
.outbuffer
, &data
, &len
);
6523 if ((unsigned)len
> c
->v
.v2
.remwindow
)
6524 len
= c
->v
.v2
.remwindow
;
6525 if ((unsigned)len
> c
->v
.v2
.remmaxpkt
)
6526 len
= c
->v
.v2
.remmaxpkt
;
6527 pktout
= ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA
);
6528 ssh2_pkt_adduint32(pktout
, c
->remoteid
);
6529 ssh2_pkt_addstring_start(pktout
);
6530 dont_log_data(ssh
, pktout
, PKTLOG_OMIT
);
6531 ssh2_pkt_addstring_data(pktout
, data
, len
);
6532 end_log_omission(ssh
, pktout
);
6533 ssh2_pkt_send(ssh
, pktout
);
6534 bufchain_consume(&c
->v
.v2
.outbuffer
, len
);
6535 c
->v
.v2
.remwindow
-= len
;
6539 * After having sent as much data as we can, return the amount
6542 ret
= bufchain_size(&c
->v
.v2
.outbuffer
);
6545 * And if there's no data pending but we need to send an EOF, send
6548 if (!ret
&& c
->pending_eof
)
6549 ssh_channel_try_eof(c
);
6554 static void ssh2_try_send_and_unthrottle(Ssh ssh
, struct ssh_channel
*c
)
6557 if (c
->closes
& CLOSES_SENT_EOF
)
6558 return; /* don't send on channels we've EOFed */
6559 bufsize
= ssh2_try_send(c
);
6562 case CHAN_MAINSESSION
:
6563 /* stdin need not receive an unthrottle
6564 * notification since it will be polled */
6567 x11_unthrottle(c
->u
.x11
.s
);
6570 /* agent sockets are request/response and need no
6571 * buffer management */
6574 pfd_unthrottle(c
->u
.pfd
.s
);
6581 * Set up most of a new ssh_channel for SSH-2.
6583 static void ssh2_channel_init(struct ssh_channel
*c
)
6586 c
->localid
= alloc_channel_id(ssh
);
6588 c
->pending_eof
= FALSE
;
6589 c
->throttling_conn
= FALSE
;
6590 c
->v
.v2
.locwindow
= c
->v
.v2
.locmaxwin
= c
->v
.v2
.remlocwin
=
6591 conf_get_int(ssh
->conf
, CONF_ssh_simple
) ? OUR_V2_BIGWIN
: OUR_V2_WINSIZE
;
6592 c
->v
.v2
.winadj_head
= c
->v
.v2
.winadj_tail
= NULL
;
6593 c
->v
.v2
.throttle_state
= UNTHROTTLED
;
6594 bufchain_init(&c
->v
.v2
.outbuffer
);
6598 * Potentially enlarge the window on an SSH-2 channel.
6600 static void ssh2_set_window(struct ssh_channel
*c
, int newwin
)
6605 * Never send WINDOW_ADJUST for a channel that the remote side has
6606 * already sent EOF on; there's no point, since it won't be
6607 * sending any more data anyway. Ditto if _we've_ already sent
6610 if (c
->closes
& (CLOSES_RCVD_EOF
| CLOSES_SENT_CLOSE
))
6614 * If the remote end has a habit of ignoring maxpkt, limit the
6615 * window so that it has no choice (assuming it doesn't ignore the
6618 if ((ssh
->remote_bugs
& BUG_SSH2_MAXPKT
) && newwin
> OUR_V2_MAXPKT
)
6619 newwin
= OUR_V2_MAXPKT
;
6622 * Only send a WINDOW_ADJUST if there's significantly more window
6623 * available than the other end thinks there is. This saves us
6624 * sending a WINDOW_ADJUST for every character in a shell session.
6626 * "Significant" is arbitrarily defined as half the window size.
6628 if (newwin
/ 2 >= c
->v
.v2
.locwindow
) {
6629 struct Packet
*pktout
;
6633 * In order to keep track of how much window the client
6634 * actually has available, we'd like it to acknowledge each
6635 * WINDOW_ADJUST. We can't do that directly, so we accompany
6636 * it with a CHANNEL_REQUEST that has to be acknowledged.
6638 * This is only necessary if we're opening the window wide.
6639 * If we're not, then throughput is being constrained by
6640 * something other than the maximum window size anyway.
6642 * We also only send this if the main channel has finished its
6643 * initial CHANNEL_REQUESTs and installed the default
6644 * CHANNEL_FAILURE handler, so as not to risk giving it
6645 * unexpected CHANNEL_FAILUREs.
6647 if (newwin
== c
->v
.v2
.locmaxwin
&&
6648 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_FAILURE
] &&
6649 !(ssh
->remote_bugs
& BUG_CHOKES_ON_WINADJ
)) {
6650 pktout
= ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
6651 ssh2_pkt_adduint32(pktout
, c
->remoteid
);
6652 ssh2_pkt_addstring(pktout
, "winadj@putty.projects.tartarus.org");
6653 ssh2_pkt_addbool(pktout
, TRUE
);
6654 ssh2_pkt_send(ssh
, pktout
);
6657 * CHANNEL_FAILURE doesn't come with any indication of
6658 * what message caused it, so we have to keep track of the
6659 * outstanding CHANNEL_REQUESTs ourselves.
6661 wa
= snew(struct winadj
);
6662 wa
->size
= newwin
- c
->v
.v2
.locwindow
;
6664 if (!c
->v
.v2
.winadj_head
)
6665 c
->v
.v2
.winadj_head
= wa
;
6667 c
->v
.v2
.winadj_tail
->next
= wa
;
6668 c
->v
.v2
.winadj_tail
= wa
;
6669 if (c
->v
.v2
.throttle_state
!= UNTHROTTLED
)
6670 c
->v
.v2
.throttle_state
= UNTHROTTLING
;
6672 /* Pretend the WINDOW_ADJUST was acked immediately. */
6673 c
->v
.v2
.remlocwin
= newwin
;
6674 c
->v
.v2
.throttle_state
= THROTTLED
;
6676 pktout
= ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
6677 ssh2_pkt_adduint32(pktout
, c
->remoteid
);
6678 ssh2_pkt_adduint32(pktout
, newwin
- c
->v
.v2
.locwindow
);
6679 ssh2_pkt_send(ssh
, pktout
);
6680 c
->v
.v2
.locwindow
= newwin
;
6685 * Find the channel associated with a message. If there's no channel,
6686 * or it's not properly open, make a noise about it and return NULL.
6688 static struct ssh_channel
*ssh2_channel_msg(Ssh ssh
, struct Packet
*pktin
)
6690 unsigned localid
= ssh_pkt_getuint32(pktin
);
6691 struct ssh_channel
*c
;
6693 c
= find234(ssh
->channels
, &localid
, ssh_channelfind
);
6695 (c
->halfopen
&& pktin
->type
!= SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
&&
6696 pktin
->type
!= SSH2_MSG_CHANNEL_OPEN_FAILURE
)) {
6697 char *buf
= dupprintf("Received %s for %s channel %u",
6698 ssh2_pkt_type(ssh
->pkt_kctx
, ssh
->pkt_actx
,
6700 c ?
"half-open" : "nonexistent", localid
);
6701 ssh_disconnect(ssh
, NULL
, buf
, SSH2_DISCONNECT_PROTOCOL_ERROR
, FALSE
);
6708 static int ssh2_handle_winadj_response(struct ssh_channel
*c
)
6710 struct winadj
*wa
= c
->v
.v2
.winadj_head
;
6713 c
->v
.v2
.winadj_head
= wa
->next
;
6714 c
->v
.v2
.remlocwin
+= wa
->size
;
6717 * winadj messages are only sent when the window is fully open, so
6718 * if we get an ack of one, we know any pending unthrottle is
6721 if (c
->v
.v2
.throttle_state
== UNTHROTTLING
)
6722 c
->v
.v2
.throttle_state
= UNTHROTTLED
;
6724 * We may now initiate channel-closing procedures, if that winadj
6725 * was the last thing outstanding before we send CHANNEL_CLOSE.
6727 ssh2_channel_check_close(c
);
6731 static void ssh2_msg_channel_success(Ssh ssh
, struct Packet
*pktin
)
6734 * This should never get called. All channel requests are either
6735 * sent with want_reply false, are sent before this handler gets
6736 * installed, or are "winadj@putty" requests, which servers should
6737 * never respond to with success.
6739 * However, at least one server ("boks_sshd") is known to return
6740 * SUCCESS for channel requests it's never heard of, such as
6741 * "winadj@putty". Raised with foxt.com as bug 090916-090424, but
6742 * for the sake of a quiet life, we handle it just the same as the
6745 struct ssh_channel
*c
;
6747 c
= ssh2_channel_msg(ssh
, pktin
);
6750 if (!ssh2_handle_winadj_response(c
))
6751 ssh_disconnect(ssh
, NULL
,
6752 "Received unsolicited SSH_MSG_CHANNEL_SUCCESS",
6753 SSH2_DISCONNECT_PROTOCOL_ERROR
, FALSE
);
6756 static void ssh2_msg_channel_failure(Ssh ssh
, struct Packet
*pktin
)
6759 * The only time this should get called is for "winadj@putty"
6760 * messages sent above. All other channel requests are either
6761 * sent with want_reply false or are sent before this handler gets
6764 struct ssh_channel
*c
;
6766 c
= ssh2_channel_msg(ssh
, pktin
);
6769 if (!ssh2_handle_winadj_response(c
))
6770 ssh_disconnect(ssh
, NULL
,
6771 "Received unsolicited SSH_MSG_CHANNEL_FAILURE",
6772 SSH2_DISCONNECT_PROTOCOL_ERROR
, FALSE
);
6775 static void ssh2_msg_channel_window_adjust(Ssh ssh
, struct Packet
*pktin
)
6777 struct ssh_channel
*c
;
6778 c
= ssh2_channel_msg(ssh
, pktin
);
6781 if (!(c
->closes
& CLOSES_SENT_EOF
)) {
6782 c
->v
.v2
.remwindow
+= ssh_pkt_getuint32(pktin
);
6783 ssh2_try_send_and_unthrottle(ssh
, c
);
6787 static void ssh2_msg_channel_data(Ssh ssh
, struct Packet
*pktin
)
6791 struct ssh_channel
*c
;
6792 c
= ssh2_channel_msg(ssh
, pktin
);
6795 if (pktin
->type
== SSH2_MSG_CHANNEL_EXTENDED_DATA
&&
6796 ssh_pkt_getuint32(pktin
) != SSH2_EXTENDED_DATA_STDERR
)
6797 return; /* extended but not stderr */
6798 ssh_pkt_getstring(pktin
, &data
, &length
);
6801 c
->v
.v2
.locwindow
-= length
;
6802 c
->v
.v2
.remlocwin
-= length
;
6804 case CHAN_MAINSESSION
:
6806 from_backend(ssh
->frontend
, pktin
->type
==
6807 SSH2_MSG_CHANNEL_EXTENDED_DATA
,
6811 bufsize
= x11_send(c
->u
.x11
.s
, data
, length
);
6814 bufsize
= pfd_send(c
->u
.pfd
.s
, data
, length
);
6817 while (length
> 0) {
6818 if (c
->u
.a
.lensofar
< 4) {
6819 unsigned int l
= min(4 - c
->u
.a
.lensofar
,
6821 memcpy(c
->u
.a
.msglen
+ c
->u
.a
.lensofar
,
6825 c
->u
.a
.lensofar
+= l
;
6827 if (c
->u
.a
.lensofar
== 4) {
6829 4 + GET_32BIT(c
->u
.a
.msglen
);
6830 c
->u
.a
.message
= snewn(c
->u
.a
.totallen
,
6832 memcpy(c
->u
.a
.message
, c
->u
.a
.msglen
, 4);
6834 if (c
->u
.a
.lensofar
>= 4 && length
> 0) {
6836 min(c
->u
.a
.totallen
- c
->u
.a
.lensofar
,
6838 memcpy(c
->u
.a
.message
+ c
->u
.a
.lensofar
,
6842 c
->u
.a
.lensofar
+= l
;
6844 if (c
->u
.a
.lensofar
== c
->u
.a
.totallen
) {
6847 if (agent_query(c
->u
.a
.message
,
6850 ssh_agentf_callback
, c
))
6851 ssh_agentf_callback(c
, reply
, replylen
);
6852 sfree(c
->u
.a
.message
);
6853 c
->u
.a
.message
= NULL
;
6854 c
->u
.a
.lensofar
= 0;
6861 * If it looks like the remote end hit the end of its window,
6862 * and we didn't want it to do that, think about using a
6865 if (c
->v
.v2
.remlocwin
<= 0 && c
->v
.v2
.throttle_state
== UNTHROTTLED
&&
6866 c
->v
.v2
.locmaxwin
< 0x40000000)
6867 c
->v
.v2
.locmaxwin
+= OUR_V2_WINSIZE
;
6869 * If we are not buffering too much data,
6870 * enlarge the window again at the remote side.
6871 * If we are buffering too much, we may still
6872 * need to adjust the window if the server's
6875 ssh2_set_window(c
, bufsize
< c
->v
.v2
.locmaxwin ?
6876 c
->v
.v2
.locmaxwin
- bufsize
: 0);
6878 * If we're either buffering way too much data, or if we're
6879 * buffering anything at all and we're in "simple" mode,
6880 * throttle the whole channel.
6882 if ((bufsize
> c
->v
.v2
.locmaxwin
||
6883 (conf_get_int(ssh
->conf
, CONF_ssh_simple
) && bufsize
> 0)) &&
6884 !c
->throttling_conn
) {
6885 c
->throttling_conn
= 1;
6886 ssh_throttle_conn(ssh
, +1);
6891 static void ssh_channel_destroy(struct ssh_channel
*c
)
6896 case CHAN_MAINSESSION
:
6897 ssh
->mainchan
= NULL
;
6898 update_specials_menu(ssh
->frontend
);
6901 if (c
->u
.x11
.s
!= NULL
)
6902 x11_close(c
->u
.x11
.s
);
6903 logevent("Forwarded X11 connection terminated");
6906 sfree(c
->u
.a
.message
);
6909 if (c
->u
.pfd
.s
!= NULL
)
6910 pfd_close(c
->u
.pfd
.s
);
6911 logevent("Forwarded port closed");
6915 del234(ssh
->channels
, c
);
6916 if (ssh
->version
== 2)
6917 bufchain_clear(&c
->v
.v2
.outbuffer
);
6921 * See if that was the last channel left open.
6922 * (This is only our termination condition if we're
6923 * not running in -N mode.)
6925 if (ssh
->version
== 2 &&
6926 !conf_get_int(ssh
->conf
, CONF_ssh_no_shell
) &&
6927 count234(ssh
->channels
) == 0) {
6929 * We used to send SSH_MSG_DISCONNECT here,
6930 * because I'd believed that _every_ conforming
6931 * SSH-2 connection had to end with a disconnect
6932 * being sent by at least one side; apparently
6933 * I was wrong and it's perfectly OK to
6934 * unceremoniously slam the connection shut
6935 * when you're done, and indeed OpenSSH feels
6936 * this is more polite than sending a
6937 * DISCONNECT. So now we don't.
6939 ssh_disconnect(ssh
, "All channels closed", NULL
, 0, TRUE
);
6943 static void ssh2_channel_check_close(struct ssh_channel
*c
)
6946 struct Packet
*pktout
;
6948 if ((c
->closes
& (CLOSES_SENT_EOF
| CLOSES_RCVD_EOF
| CLOSES_SENT_CLOSE
))
6949 == (CLOSES_SENT_EOF
| CLOSES_RCVD_EOF
) && !c
->v
.v2
.winadj_head
) {
6951 * We have both sent and received EOF, and we have no
6952 * outstanding winadj channel requests, which means the
6953 * channel is in final wind-up. But we haven't sent CLOSE, so
6956 pktout
= ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE
);
6957 ssh2_pkt_adduint32(pktout
, c
->remoteid
);
6958 ssh2_pkt_send(ssh
, pktout
);
6959 c
->closes
|= CLOSES_SENT_CLOSE
;
6962 if (!((CLOSES_SENT_CLOSE
| CLOSES_RCVD_CLOSE
) & ~c
->closes
)) {
6964 * We have both sent and received CLOSE, which means we're
6965 * completely done with the channel.
6967 ssh_channel_destroy(c
);
6971 static void ssh2_channel_got_eof(struct ssh_channel
*c
)
6973 if (c
->closes
& CLOSES_RCVD_EOF
)
6974 return; /* already seen EOF */
6975 c
->closes
|= CLOSES_RCVD_EOF
;
6977 if (c
->type
== CHAN_X11
) {
6978 x11_send_eof(c
->u
.x11
.s
);
6979 } else if (c
->type
== CHAN_AGENT
) {
6980 /* Manufacture an outgoing EOF in response to the incoming one. */
6981 sshfwd_write_eof(c
);
6982 } else if (c
->type
== CHAN_SOCKDATA
) {
6983 pfd_send_eof(c
->u
.pfd
.s
);
6984 } else if (c
->type
== CHAN_MAINSESSION
) {
6987 if (!ssh
->sent_console_eof
&&
6988 (from_backend_eof(ssh
->frontend
) || ssh
->got_pty
)) {
6990 * Either from_backend_eof told us that the front end
6991 * wants us to close the outgoing side of the connection
6992 * as soon as we see EOF from the far end, or else we've
6993 * unilaterally decided to do that because we've allocated
6994 * a remote pty and hence EOF isn't a particularly
6995 * meaningful concept.
6997 sshfwd_write_eof(c
);
6999 ssh
->sent_console_eof
= TRUE
;
7002 ssh2_channel_check_close(c
);
7005 static void ssh2_msg_channel_eof(Ssh ssh
, struct Packet
*pktin
)
7007 struct ssh_channel
*c
;
7009 c
= ssh2_channel_msg(ssh
, pktin
);
7012 ssh2_channel_got_eof(c
);
7015 static void ssh2_msg_channel_close(Ssh ssh
, struct Packet
*pktin
)
7017 struct ssh_channel
*c
;
7019 c
= ssh2_channel_msg(ssh
, pktin
);
7024 * When we receive CLOSE on a channel, we assume it comes with an
7025 * implied EOF if we haven't seen EOF yet.
7027 ssh2_channel_got_eof(c
);
7030 * And we also send an outgoing EOF, if we haven't already, on the
7031 * assumption that CLOSE is a pretty forceful announcement that
7032 * the remote side is doing away with the entire channel. (If it
7033 * had wanted to send us EOF and continue receiving data from us,
7034 * it would have just sent CHANNEL_EOF.)
7036 if (!(c
->closes
& CLOSES_SENT_EOF
)) {
7038 * Make sure we don't read any more from whatever our local
7039 * data source is for this channel.
7042 case CHAN_MAINSESSION
:
7043 ssh
->send_ok
= 0; /* stop trying to read from stdin */
7046 x11_override_throttle(c
->u
.x11
.s
, 1);
7049 pfd_override_throttle(c
->u
.pfd
.s
, 1);
7054 * Send outgoing EOF.
7056 sshfwd_write_eof(c
);
7060 * Now process the actual close.
7062 if (!(c
->closes
& CLOSES_RCVD_CLOSE
)) {
7063 c
->closes
|= CLOSES_RCVD_CLOSE
;
7064 ssh2_channel_check_close(c
);
7068 static void ssh2_msg_channel_open_confirmation(Ssh ssh
, struct Packet
*pktin
)
7070 struct ssh_channel
*c
;
7072 c
= ssh2_channel_msg(ssh
, pktin
);
7075 if (c
->type
!= CHAN_SOCKDATA_DORMANT
)
7076 return; /* dunno why they're confirming this */
7077 c
->remoteid
= ssh_pkt_getuint32(pktin
);
7078 c
->halfopen
= FALSE
;
7079 c
->type
= CHAN_SOCKDATA
;
7080 c
->v
.v2
.remwindow
= ssh_pkt_getuint32(pktin
);
7081 c
->v
.v2
.remmaxpkt
= ssh_pkt_getuint32(pktin
);
7083 pfd_confirm(c
->u
.pfd
.s
);
7085 ssh_channel_try_eof(c
);
7088 static void ssh2_msg_channel_open_failure(Ssh ssh
, struct Packet
*pktin
)
7090 static const char *const reasons
[] = {
7091 "<unknown reason code>",
7092 "Administratively prohibited",
7094 "Unknown channel type",
7095 "Resource shortage",
7097 unsigned reason_code
;
7098 char *reason_string
;
7100 struct ssh_channel
*c
;
7101 c
= ssh2_channel_msg(ssh
, pktin
);
7104 if (c
->type
!= CHAN_SOCKDATA_DORMANT
)
7105 return; /* dunno why they're failing this */
7107 reason_code
= ssh_pkt_getuint32(pktin
);
7108 if (reason_code
>= lenof(reasons
))
7109 reason_code
= 0; /* ensure reasons[reason_code] in range */
7110 ssh_pkt_getstring(pktin
, &reason_string
, &reason_length
);
7111 logeventf(ssh
, "Forwarded connection refused by server: %s [%.*s]",
7112 reasons
[reason_code
], reason_length
, reason_string
);
7114 pfd_close(c
->u
.pfd
.s
);
7116 del234(ssh
->channels
, c
);
7120 static void ssh2_msg_channel_request(Ssh ssh
, struct Packet
*pktin
)
7123 int typelen
, want_reply
;
7124 int reply
= SSH2_MSG_CHANNEL_FAILURE
; /* default */
7125 struct ssh_channel
*c
;
7126 struct Packet
*pktout
;
7128 c
= ssh2_channel_msg(ssh
, pktin
);
7131 ssh_pkt_getstring(pktin
, &type
, &typelen
);
7132 want_reply
= ssh2_pkt_getbool(pktin
);
7135 * Having got the channel number, we now look at
7136 * the request type string to see if it's something
7139 if (c
== ssh
->mainchan
) {
7141 * We recognise "exit-status" and "exit-signal" on
7142 * the primary channel.
7144 if (typelen
== 11 &&
7145 !memcmp(type
, "exit-status", 11)) {
7147 ssh
->exitcode
= ssh_pkt_getuint32(pktin
);
7148 logeventf(ssh
, "Server sent command exit status %d",
7150 reply
= SSH2_MSG_CHANNEL_SUCCESS
;
7152 } else if (typelen
== 11 &&
7153 !memcmp(type
, "exit-signal", 11)) {
7155 int is_plausible
= TRUE
, is_int
= FALSE
;
7156 char *fmt_sig
= "", *fmt_msg
= "";
7158 int msglen
= 0, core
= FALSE
;
7159 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
7160 * provide an `int' for the signal, despite its
7161 * having been a `string' in the drafts of RFC 4254 since at
7162 * least 2001. (Fixed in session.c 1.147.) Try to
7163 * infer which we can safely parse it as. */
7165 unsigned char *p
= pktin
->body
+
7167 long len
= pktin
->length
- pktin
->savedpos
;
7168 unsigned long num
= GET_32BIT(p
); /* what is it? */
7169 /* If it's 0, it hardly matters; assume string */
7173 int maybe_int
= FALSE
, maybe_str
= FALSE
;
7174 #define CHECK_HYPOTHESIS(offset, result) \
7177 if (q >= 0 && q+4 <= len) { \
7178 q = q + 4 + GET_32BIT(p+q); \
7179 if (q >= 0 && q+4 <= len && \
7180 ((q = q + 4 + GET_32BIT(p+q))!= 0) && q == len) \
7184 CHECK_HYPOTHESIS(4+1, maybe_int
);
7185 CHECK_HYPOTHESIS(4+num
+1, maybe_str
);
7186 #undef CHECK_HYPOTHESIS
7187 if (maybe_int
&& !maybe_str
)
7189 else if (!maybe_int
&& maybe_str
)
7192 /* Crikey. Either or neither. Panic. */
7193 is_plausible
= FALSE
;
7196 ssh
->exitcode
= 128; /* means `unknown signal' */
7199 /* Old non-standard OpenSSH. */
7200 int signum
= ssh_pkt_getuint32(pktin
);
7201 fmt_sig
= dupprintf(" %d", signum
);
7202 ssh
->exitcode
= 128 + signum
;
7204 /* As per RFC 4254. */
7207 ssh_pkt_getstring(pktin
, &sig
, &siglen
);
7208 /* Signal name isn't supposed to be blank, but
7209 * let's cope gracefully if it is. */
7211 fmt_sig
= dupprintf(" \"%.*s\"",
7216 * Really hideous method of translating the
7217 * signal description back into a locally
7218 * meaningful number.
7223 #define TRANSLATE_SIGNAL(s) \
7224 else if (siglen == lenof(#s)-1 && !memcmp(sig, #s, siglen)) \
7225 ssh->exitcode = 128 + SIG ## s
7227 TRANSLATE_SIGNAL(ABRT
);
7230 TRANSLATE_SIGNAL(ALRM
);
7233 TRANSLATE_SIGNAL(FPE
);
7236 TRANSLATE_SIGNAL(HUP
);
7239 TRANSLATE_SIGNAL(ILL
);
7242 TRANSLATE_SIGNAL(INT
);
7245 TRANSLATE_SIGNAL(KILL
);
7248 TRANSLATE_SIGNAL(PIPE
);
7251 TRANSLATE_SIGNAL(QUIT
);
7254 TRANSLATE_SIGNAL(SEGV
);
7257 TRANSLATE_SIGNAL(TERM
);
7260 TRANSLATE_SIGNAL(USR1
);
7263 TRANSLATE_SIGNAL(USR2
);
7265 #undef TRANSLATE_SIGNAL
7267 ssh
->exitcode
= 128;
7269 core
= ssh2_pkt_getbool(pktin
);
7270 ssh_pkt_getstring(pktin
, &msg
, &msglen
);
7272 fmt_msg
= dupprintf(" (\"%.*s\")", msglen
, msg
);
7274 /* ignore lang tag */
7275 } /* else don't attempt to parse */
7276 logeventf(ssh
, "Server exited on signal%s%s%s",
7277 fmt_sig
, core ?
" (core dumped)" : "",
7279 if (*fmt_sig
) sfree(fmt_sig
);
7280 if (*fmt_msg
) sfree(fmt_msg
);
7281 reply
= SSH2_MSG_CHANNEL_SUCCESS
;
7286 * This is a channel request we don't know
7287 * about, so we now either ignore the request
7288 * or respond with CHANNEL_FAILURE, depending
7291 reply
= SSH2_MSG_CHANNEL_FAILURE
;
7294 pktout
= ssh2_pkt_init(reply
);
7295 ssh2_pkt_adduint32(pktout
, c
->remoteid
);
7296 ssh2_pkt_send(ssh
, pktout
);
7300 static void ssh2_msg_global_request(Ssh ssh
, struct Packet
*pktin
)
7303 int typelen
, want_reply
;
7304 struct Packet
*pktout
;
7306 ssh_pkt_getstring(pktin
, &type
, &typelen
);
7307 want_reply
= ssh2_pkt_getbool(pktin
);
7310 * We currently don't support any global requests
7311 * at all, so we either ignore the request or
7312 * respond with REQUEST_FAILURE, depending on
7316 pktout
= ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE
);
7317 ssh2_pkt_send(ssh
, pktout
);
7321 static void ssh2_msg_channel_open(Ssh ssh
, struct Packet
*pktin
)
7329 struct ssh_channel
*c
;
7330 unsigned remid
, winsize
, pktsize
;
7331 struct Packet
*pktout
;
7333 ssh_pkt_getstring(pktin
, &type
, &typelen
);
7334 c
= snew(struct ssh_channel
);
7337 remid
= ssh_pkt_getuint32(pktin
);
7338 winsize
= ssh_pkt_getuint32(pktin
);
7339 pktsize
= ssh_pkt_getuint32(pktin
);
7341 if (typelen
== 3 && !memcmp(type
, "x11", 3)) {
7345 ssh_pkt_getstring(pktin
, &peeraddr
, &peeraddrlen
);
7346 addrstr
= snewn(peeraddrlen
+1, char);
7347 memcpy(addrstr
, peeraddr
, peeraddrlen
);
7348 addrstr
[peeraddrlen
] = '\0';
7349 peerport
= ssh_pkt_getuint32(pktin
);
7351 logeventf(ssh
, "Received X11 connect request from %s:%d",
7354 if (!ssh
->X11_fwd_enabled
)
7355 error
= "X11 forwarding is not enabled";
7356 else if ((x11err
= x11_init(&c
->u
.x11
.s
, ssh
->x11disp
, c
,
7357 addrstr
, peerport
, ssh
->conf
)) != NULL
) {
7358 logeventf(ssh
, "Local X11 connection failed: %s", x11err
);
7359 error
= "Unable to open an X11 connection";
7361 logevent("Opening X11 forward connection succeeded");
7366 } else if (typelen
== 15 &&
7367 !memcmp(type
, "forwarded-tcpip", 15)) {
7368 struct ssh_rportfwd pf
, *realpf
;
7371 ssh_pkt_getstring(pktin
, &dummy
, &dummylen
);/* skip address */
7372 pf
.sport
= ssh_pkt_getuint32(pktin
);
7373 ssh_pkt_getstring(pktin
, &peeraddr
, &peeraddrlen
);
7374 peerport
= ssh_pkt_getuint32(pktin
);
7375 realpf
= find234(ssh
->rportfwds
, &pf
, NULL
);
7376 logeventf(ssh
, "Received remote port %d open request "
7377 "from %s:%d", pf
.sport
, peeraddr
, peerport
);
7378 if (realpf
== NULL
) {
7379 error
= "Remote port is not recognised";
7381 const char *e
= pfd_newconnect(&c
->u
.pfd
.s
,
7385 realpf
->pfrec
->addressfamily
);
7386 logeventf(ssh
, "Attempting to forward remote port to "
7387 "%s:%d", realpf
->dhost
, realpf
->dport
);
7389 logeventf(ssh
, "Port open failed: %s", e
);
7390 error
= "Port open failed";
7392 logevent("Forwarded port opened successfully");
7393 c
->type
= CHAN_SOCKDATA
;
7396 } else if (typelen
== 22 &&
7397 !memcmp(type
, "auth-agent@openssh.com", 22)) {
7398 if (!ssh
->agentfwd_enabled
)
7399 error
= "Agent forwarding is not enabled";
7401 c
->type
= CHAN_AGENT
; /* identify channel type */
7402 c
->u
.a
.lensofar
= 0;
7405 error
= "Unsupported channel type requested";
7408 c
->remoteid
= remid
;
7409 c
->halfopen
= FALSE
;
7411 pktout
= ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE
);
7412 ssh2_pkt_adduint32(pktout
, c
->remoteid
);
7413 ssh2_pkt_adduint32(pktout
, SSH2_OPEN_CONNECT_FAILED
);
7414 ssh2_pkt_addstring(pktout
, error
);
7415 ssh2_pkt_addstring(pktout
, "en"); /* language tag */
7416 ssh2_pkt_send(ssh
, pktout
);
7417 logeventf(ssh
, "Rejected channel open: %s", error
);
7420 ssh2_channel_init(c
);
7421 c
->v
.v2
.remwindow
= winsize
;
7422 c
->v
.v2
.remmaxpkt
= pktsize
;
7423 add234(ssh
->channels
, c
);
7424 pktout
= ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
);
7425 ssh2_pkt_adduint32(pktout
, c
->remoteid
);
7426 ssh2_pkt_adduint32(pktout
, c
->localid
);
7427 ssh2_pkt_adduint32(pktout
, c
->v
.v2
.locwindow
);
7428 ssh2_pkt_adduint32(pktout
, OUR_V2_MAXPKT
); /* our max pkt size */
7429 ssh2_pkt_send(ssh
, pktout
);
7434 * Buffer banner messages for later display at some convenient point,
7435 * if we're going to display them.
7437 static void ssh2_msg_userauth_banner(Ssh ssh
, struct Packet
*pktin
)
7439 /* Arbitrary limit to prevent unbounded inflation of buffer */
7440 if (conf_get_int(ssh
->conf
, CONF_ssh_show_banner
) &&
7441 bufchain_size(&ssh
->banner
) <= 131072) {
7442 char *banner
= NULL
;
7444 ssh_pkt_getstring(pktin
, &banner
, &size
);
7446 bufchain_add(&ssh
->banner
, banner
, size
);
7450 /* Helper function to deal with sending tty modes for "pty-req" */
7451 static void ssh2_send_ttymode(void *data
, char *mode
, char *val
)
7453 struct Packet
*pktout
= (struct Packet
*)data
;
7455 unsigned int arg
= 0;
7456 while (strcmp(mode
, ssh_ttymodes
[i
].mode
) != 0) i
++;
7457 if (i
== lenof(ssh_ttymodes
)) return;
7458 switch (ssh_ttymodes
[i
].type
) {
7460 arg
= ssh_tty_parse_specchar(val
);
7463 arg
= ssh_tty_parse_boolean(val
);
7466 ssh2_pkt_addbyte(pktout
, ssh_ttymodes
[i
].opcode
);
7467 ssh2_pkt_adduint32(pktout
, arg
);
7471 * Handle the SSH-2 userauth and connection layers.
7473 static void do_ssh2_authconn(Ssh ssh
, unsigned char *in
, int inlen
,
7474 struct Packet
*pktin
)
7476 struct do_ssh2_authconn_state
{
7479 AUTH_TYPE_PUBLICKEY
,
7480 AUTH_TYPE_PUBLICKEY_OFFER_LOUD
,
7481 AUTH_TYPE_PUBLICKEY_OFFER_QUIET
,
7483 AUTH_TYPE_GSSAPI
, /* always QUIET */
7484 AUTH_TYPE_KEYBOARD_INTERACTIVE
,
7485 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
7487 int done_service_req
;
7488 int gotit
, need_pw
, can_pubkey
, can_passwd
, can_keyb_inter
;
7489 int tried_pubkey_config
, done_agent
;
7494 int kbd_inter_refused
;
7495 int we_are_in
, userauth_success
;
7496 prompts_t
*cur_prompt
;
7501 void *publickey_blob
;
7502 int publickey_bloblen
;
7503 int publickey_encrypted
;
7504 char *publickey_algorithm
;
7505 char *publickey_comment
;
7506 unsigned char agent_request
[5], *agent_response
, *agentp
;
7507 int agent_responselen
;
7508 unsigned char *pkblob_in_agent
;
7510 char *pkblob
, *alg
, *commentp
;
7511 int pklen
, alglen
, commentlen
;
7512 int siglen
, retlen
, len
;
7513 char *q
, *agentreq
, *ret
;
7516 int requested_agent
;
7518 int num_env
, env_left
, env_ok
;
7519 struct Packet
*pktout
;
7522 struct ssh_gss_library
*gsslib
;
7523 Ssh_gss_ctx gss_ctx
;
7524 Ssh_gss_buf gss_buf
;
7525 Ssh_gss_buf gss_rcvtok
, gss_sndtok
;
7526 Ssh_gss_name gss_srv_name
;
7527 Ssh_gss_stat gss_stat
;
7530 crState(do_ssh2_authconn_state
);
7532 crBegin(ssh
->do_ssh2_authconn_crstate
);
7534 s
->done_service_req
= FALSE
;
7535 s
->we_are_in
= s
->userauth_success
= FALSE
;
7537 s
->tried_gssapi
= FALSE
;
7540 if (!conf_get_int(ssh
->conf
, CONF_ssh_no_userauth
)) {
7542 * Request userauth protocol, and await a response to it.
7544 s
->pktout
= ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST
);
7545 ssh2_pkt_addstring(s
->pktout
, "ssh-userauth");
7546 ssh2_pkt_send(ssh
, s
->pktout
);
7547 crWaitUntilV(pktin
);
7548 if (pktin
->type
== SSH2_MSG_SERVICE_ACCEPT
)
7549 s
->done_service_req
= TRUE
;
7551 if (!s
->done_service_req
) {
7553 * Request connection protocol directly, without authentication.
7555 s
->pktout
= ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST
);
7556 ssh2_pkt_addstring(s
->pktout
, "ssh-connection");
7557 ssh2_pkt_send(ssh
, s
->pktout
);
7558 crWaitUntilV(pktin
);
7559 if (pktin
->type
== SSH2_MSG_SERVICE_ACCEPT
) {
7560 s
->we_are_in
= TRUE
; /* no auth required */
7562 bombout(("Server refused service request"));
7567 /* Arrange to be able to deal with any BANNERs that come in.
7568 * (We do this now as packets may come in during the next bit.) */
7569 bufchain_init(&ssh
->banner
);
7570 ssh
->packet_dispatch
[SSH2_MSG_USERAUTH_BANNER
] =
7571 ssh2_msg_userauth_banner
;
7574 * Misc one-time setup for authentication.
7576 s
->publickey_blob
= NULL
;
7577 if (!s
->we_are_in
) {
7580 * Load the public half of any configured public key file
7583 s
->keyfile
= conf_get_filename(ssh
->conf
, CONF_keyfile
);
7584 if (!filename_is_null(s
->keyfile
)) {
7586 logeventf(ssh
, "Reading private key file \"%.150s\"",
7587 filename_to_str(s
->keyfile
));
7588 keytype
= key_type(s
->keyfile
);
7589 if (keytype
== SSH_KEYTYPE_SSH2
) {
7592 ssh2_userkey_loadpub(s
->keyfile
,
7593 &s
->publickey_algorithm
,
7594 &s
->publickey_bloblen
,
7595 &s
->publickey_comment
, &error
);
7596 if (s
->publickey_blob
) {
7597 s
->publickey_encrypted
=
7598 ssh2_userkey_encrypted(s
->keyfile
, NULL
);
7601 logeventf(ssh
, "Unable to load private key (%s)",
7603 msgbuf
= dupprintf("Unable to load private key file "
7604 "\"%.150s\" (%s)\r\n",
7605 filename_to_str(s
->keyfile
),
7607 c_write_str(ssh
, msgbuf
);
7612 logeventf(ssh
, "Unable to use this key file (%s)",
7613 key_type_to_str(keytype
));
7614 msgbuf
= dupprintf("Unable to use key file \"%.150s\""
7616 filename_to_str(s
->keyfile
),
7617 key_type_to_str(keytype
));
7618 c_write_str(ssh
, msgbuf
);
7620 s
->publickey_blob
= NULL
;
7625 * Find out about any keys Pageant has (but if there's a
7626 * public key configured, filter out all others).
7629 s
->agent_response
= NULL
;
7630 s
->pkblob_in_agent
= NULL
;
7631 if (conf_get_int(ssh
->conf
, CONF_tryagent
) && agent_exists()) {
7635 logevent("Pageant is running. Requesting keys.");
7637 /* Request the keys held by the agent. */
7638 PUT_32BIT(s
->agent_request
, 1);
7639 s
->agent_request
[4] = SSH2_AGENTC_REQUEST_IDENTITIES
;
7640 if (!agent_query(s
->agent_request
, 5, &r
, &s
->agent_responselen
,
7641 ssh_agent_callback
, ssh
)) {
7645 bombout(("Unexpected data from server while"
7646 " waiting for agent response"));
7649 } while (pktin
|| inlen
> 0);
7650 r
= ssh
->agent_response
;
7651 s
->agent_responselen
= ssh
->agent_response_len
;
7653 s
->agent_response
= (unsigned char *) r
;
7654 if (s
->agent_response
&& s
->agent_responselen
>= 5 &&
7655 s
->agent_response
[4] == SSH2_AGENT_IDENTITIES_ANSWER
) {
7658 p
= s
->agent_response
+ 5;
7659 s
->nkeys
= GET_32BIT(p
);
7661 logeventf(ssh
, "Pageant has %d SSH-2 keys", s
->nkeys
);
7662 if (s
->publickey_blob
) {
7663 /* See if configured key is in agent. */
7664 for (keyi
= 0; keyi
< s
->nkeys
; keyi
++) {
7665 s
->pklen
= GET_32BIT(p
);
7666 if (s
->pklen
== s
->publickey_bloblen
&&
7667 !memcmp(p
+4, s
->publickey_blob
,
7668 s
->publickey_bloblen
)) {
7669 logeventf(ssh
, "Pageant key #%d matches "
7670 "configured key file", keyi
);
7672 s
->pkblob_in_agent
= p
;
7676 p
+= GET_32BIT(p
) + 4; /* comment */
7678 if (!s
->pkblob_in_agent
) {
7679 logevent("Configured key file not in Pageant");
7684 logevent("Failed to get reply from Pageant");
7691 * We repeat this whole loop, including the username prompt,
7692 * until we manage a successful authentication. If the user
7693 * types the wrong _password_, they can be sent back to the
7694 * beginning to try another username, if this is configured on.
7695 * (If they specify a username in the config, they are never
7696 * asked, even if they do give a wrong password.)
7698 * I think this best serves the needs of
7700 * - the people who have no configuration, no keys, and just
7701 * want to try repeated (username,password) pairs until they
7702 * type both correctly
7704 * - people who have keys and configuration but occasionally
7705 * need to fall back to passwords
7707 * - people with a key held in Pageant, who might not have
7708 * logged in to a particular machine before; so they want to
7709 * type a username, and then _either_ their key will be
7710 * accepted, _or_ they will type a password. If they mistype
7711 * the username they will want to be able to get back and
7714 s
->got_username
= FALSE
;
7715 while (!s
->we_are_in
) {
7719 if (s
->got_username
&& !conf_get_int(ssh
->conf
, CONF_change_username
)) {
7721 * We got a username last time round this loop, and
7722 * with change_username turned off we don't try to get
7725 } else if ((ssh
->username
= get_remote_username(ssh
->conf
)) == NULL
) {
7726 int ret
; /* need not be kept over crReturn */
7727 s
->cur_prompt
= new_prompts(ssh
->frontend
);
7728 s
->cur_prompt
->to_server
= TRUE
;
7729 s
->cur_prompt
->name
= dupstr("SSH login name");
7730 add_prompt(s
->cur_prompt
, dupstr("login as: "), TRUE
);
7731 ret
= get_userpass_input(s
->cur_prompt
, NULL
, 0);
7734 crWaitUntilV(!pktin
);
7735 ret
= get_userpass_input(s
->cur_prompt
, in
, inlen
);
7740 * get_userpass_input() failed to get a username.
7743 free_prompts(s
->cur_prompt
);
7744 ssh_disconnect(ssh
, "No username provided", NULL
, 0, TRUE
);
7747 ssh
->username
= dupstr(s
->cur_prompt
->prompts
[0]->result
);
7748 free_prompts(s
->cur_prompt
);
7751 if ((flags
& FLAG_VERBOSE
) || (flags
& FLAG_INTERACTIVE
)) {
7752 stuff
= dupprintf("Using username \"%s\".\r\n", ssh
->username
);
7753 c_write_str(ssh
, stuff
);
7757 s
->got_username
= TRUE
;
7760 * Send an authentication request using method "none": (a)
7761 * just in case it succeeds, and (b) so that we know what
7762 * authentication methods we can usefully try next.
7764 ssh
->pkt_actx
= SSH2_PKTCTX_NOAUTH
;
7766 s
->pktout
= ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
7767 ssh2_pkt_addstring(s
->pktout
, ssh
->username
);
7768 ssh2_pkt_addstring(s
->pktout
, "ssh-connection");/* service requested */
7769 ssh2_pkt_addstring(s
->pktout
, "none"); /* method */
7770 ssh2_pkt_send(ssh
, s
->pktout
);
7771 s
->type
= AUTH_TYPE_NONE
;
7773 s
->we_are_in
= FALSE
;
7775 s
->tried_pubkey_config
= FALSE
;
7776 s
->kbd_inter_refused
= FALSE
;
7778 /* Reset agent request state. */
7779 s
->done_agent
= FALSE
;
7780 if (s
->agent_response
) {
7781 if (s
->pkblob_in_agent
) {
7782 s
->agentp
= s
->pkblob_in_agent
;
7784 s
->agentp
= s
->agent_response
+ 5 + 4;
7790 char *methods
= NULL
;
7794 * Wait for the result of the last authentication request.
7797 crWaitUntilV(pktin
);
7799 * Now is a convenient point to spew any banner material
7800 * that we've accumulated. (This should ensure that when
7801 * we exit the auth loop, we haven't any left to deal
7805 int size
= bufchain_size(&ssh
->banner
);
7807 * Don't show the banner if we're operating in
7808 * non-verbose non-interactive mode. (It's probably
7809 * a script, which means nobody will read the
7810 * banner _anyway_, and moreover the printing of
7811 * the banner will screw up processing on the
7812 * output of (say) plink.)
7814 if (size
&& (flags
& (FLAG_VERBOSE
| FLAG_INTERACTIVE
))) {
7815 char *banner
= snewn(size
, char);
7816 bufchain_fetch(&ssh
->banner
, banner
, size
);
7817 c_write_untrusted(ssh
, banner
, size
);
7820 bufchain_clear(&ssh
->banner
);
7822 if (pktin
->type
== SSH2_MSG_USERAUTH_SUCCESS
) {
7823 logevent("Access granted");
7824 s
->we_are_in
= s
->userauth_success
= TRUE
;
7828 if (pktin
->type
!= SSH2_MSG_USERAUTH_FAILURE
&& s
->type
!= AUTH_TYPE_GSSAPI
) {
7829 bombout(("Strange packet received during authentication: "
7830 "type %d", pktin
->type
));
7837 * OK, we're now sitting on a USERAUTH_FAILURE message, so
7838 * we can look at the string in it and know what we can
7839 * helpfully try next.
7841 if (pktin
->type
== SSH2_MSG_USERAUTH_FAILURE
) {
7842 ssh_pkt_getstring(pktin
, &methods
, &methlen
);
7843 if (!ssh2_pkt_getbool(pktin
)) {
7845 * We have received an unequivocal Access
7846 * Denied. This can translate to a variety of
7847 * messages, or no message at all.
7849 * For forms of authentication which are attempted
7850 * implicitly, by which I mean without printing
7851 * anything in the window indicating that we're
7852 * trying them, we should never print 'Access
7855 * If we do print a message saying that we're
7856 * attempting some kind of authentication, it's OK
7857 * to print a followup message saying it failed -
7858 * but the message may sometimes be more specific
7859 * than simply 'Access denied'.
7861 * Additionally, if we'd just tried password
7862 * authentication, we should break out of this
7863 * whole loop so as to go back to the username
7864 * prompt (iff we're configured to allow
7865 * username change attempts).
7867 if (s
->type
== AUTH_TYPE_NONE
) {
7869 } else if (s
->type
== AUTH_TYPE_PUBLICKEY_OFFER_LOUD
||
7870 s
->type
== AUTH_TYPE_PUBLICKEY_OFFER_QUIET
) {
7871 if (s
->type
== AUTH_TYPE_PUBLICKEY_OFFER_LOUD
)
7872 c_write_str(ssh
, "Server refused our key\r\n");
7873 logevent("Server refused our key");
7874 } else if (s
->type
== AUTH_TYPE_PUBLICKEY
) {
7875 /* This _shouldn't_ happen except by a
7876 * protocol bug causing client and server to
7877 * disagree on what is a correct signature. */
7878 c_write_str(ssh
, "Server refused public-key signature"
7879 " despite accepting key!\r\n");
7880 logevent("Server refused public-key signature"
7881 " despite accepting key!");
7882 } else if (s
->type
==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
) {
7883 /* quiet, so no c_write */
7884 logevent("Server refused keyboard-interactive authentication");
7885 } else if (s
->type
==AUTH_TYPE_GSSAPI
) {
7886 /* always quiet, so no c_write */
7887 /* also, the code down in the GSSAPI block has
7888 * already logged this in the Event Log */
7889 } else if (s
->type
== AUTH_TYPE_KEYBOARD_INTERACTIVE
) {
7890 logevent("Keyboard-interactive authentication failed");
7891 c_write_str(ssh
, "Access denied\r\n");
7893 assert(s
->type
== AUTH_TYPE_PASSWORD
);
7894 logevent("Password authentication failed");
7895 c_write_str(ssh
, "Access denied\r\n");
7897 if (conf_get_int(ssh
->conf
, CONF_change_username
)) {
7898 /* XXX perhaps we should allow
7899 * keyboard-interactive to do this too? */
7900 s
->we_are_in
= FALSE
;
7905 c_write_str(ssh
, "Further authentication required\r\n");
7906 logevent("Further authentication required");
7910 in_commasep_string("publickey", methods
, methlen
);
7912 in_commasep_string("password", methods
, methlen
);
7913 s
->can_keyb_inter
= conf_get_int(ssh
->conf
, CONF_try_ki_auth
) &&
7914 in_commasep_string("keyboard-interactive", methods
, methlen
);
7917 ssh
->gsslibs
= ssh_gss_setup(ssh
->conf
);
7918 s
->can_gssapi
= conf_get_int(ssh
->conf
, CONF_try_gssapi_auth
) &&
7919 in_commasep_string("gssapi-with-mic", methods
, methlen
) &&
7920 ssh
->gsslibs
->nlibraries
> 0;
7924 ssh
->pkt_actx
= SSH2_PKTCTX_NOAUTH
;
7926 if (s
->can_pubkey
&& !s
->done_agent
&& s
->nkeys
) {
7929 * Attempt public-key authentication using a key from Pageant.
7932 ssh
->pkt_actx
= SSH2_PKTCTX_PUBLICKEY
;
7934 logeventf(ssh
, "Trying Pageant key #%d", s
->keyi
);
7936 /* Unpack key from agent response */
7937 s
->pklen
= GET_32BIT(s
->agentp
);
7939 s
->pkblob
= (char *)s
->agentp
;
7940 s
->agentp
+= s
->pklen
;
7941 s
->alglen
= GET_32BIT(s
->pkblob
);
7942 s
->alg
= s
->pkblob
+ 4;
7943 s
->commentlen
= GET_32BIT(s
->agentp
);
7945 s
->commentp
= (char *)s
->agentp
;
7946 s
->agentp
+= s
->commentlen
;
7947 /* s->agentp now points at next key, if any */
7949 /* See if server will accept it */
7950 s
->pktout
= ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
7951 ssh2_pkt_addstring(s
->pktout
, ssh
->username
);
7952 ssh2_pkt_addstring(s
->pktout
, "ssh-connection");
7953 /* service requested */
7954 ssh2_pkt_addstring(s
->pktout
, "publickey");
7956 ssh2_pkt_addbool(s
->pktout
, FALSE
); /* no signature included */
7957 ssh2_pkt_addstring_start(s
->pktout
);
7958 ssh2_pkt_addstring_data(s
->pktout
, s
->alg
, s
->alglen
);
7959 ssh2_pkt_addstring_start(s
->pktout
);
7960 ssh2_pkt_addstring_data(s
->pktout
, s
->pkblob
, s
->pklen
);
7961 ssh2_pkt_send(ssh
, s
->pktout
);
7962 s
->type
= AUTH_TYPE_PUBLICKEY_OFFER_QUIET
;
7964 crWaitUntilV(pktin
);
7965 if (pktin
->type
!= SSH2_MSG_USERAUTH_PK_OK
) {
7967 /* Offer of key refused. */
7974 if (flags
& FLAG_VERBOSE
) {
7975 c_write_str(ssh
, "Authenticating with "
7977 c_write(ssh
, s
->commentp
, s
->commentlen
);
7978 c_write_str(ssh
, "\" from agent\r\n");
7982 * Server is willing to accept the key.
7983 * Construct a SIGN_REQUEST.
7985 s
->pktout
= ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
7986 ssh2_pkt_addstring(s
->pktout
, ssh
->username
);
7987 ssh2_pkt_addstring(s
->pktout
, "ssh-connection");
7988 /* service requested */
7989 ssh2_pkt_addstring(s
->pktout
, "publickey");
7991 ssh2_pkt_addbool(s
->pktout
, TRUE
); /* signature included */
7992 ssh2_pkt_addstring_start(s
->pktout
);
7993 ssh2_pkt_addstring_data(s
->pktout
, s
->alg
, s
->alglen
);
7994 ssh2_pkt_addstring_start(s
->pktout
);
7995 ssh2_pkt_addstring_data(s
->pktout
, s
->pkblob
, s
->pklen
);
7997 /* Ask agent for signature. */
7998 s
->siglen
= s
->pktout
->length
- 5 + 4 +
7999 ssh
->v2_session_id_len
;
8000 if (ssh
->remote_bugs
& BUG_SSH2_PK_SESSIONID
)
8002 s
->len
= 1; /* message type */
8003 s
->len
+= 4 + s
->pklen
; /* key blob */
8004 s
->len
+= 4 + s
->siglen
; /* data to sign */
8005 s
->len
+= 4; /* flags */
8006 s
->agentreq
= snewn(4 + s
->len
, char);
8007 PUT_32BIT(s
->agentreq
, s
->len
);
8008 s
->q
= s
->agentreq
+ 4;
8009 *s
->q
++ = SSH2_AGENTC_SIGN_REQUEST
;
8010 PUT_32BIT(s
->q
, s
->pklen
);
8012 memcpy(s
->q
, s
->pkblob
, s
->pklen
);
8014 PUT_32BIT(s
->q
, s
->siglen
);
8016 /* Now the data to be signed... */
8017 if (!(ssh
->remote_bugs
& BUG_SSH2_PK_SESSIONID
)) {
8018 PUT_32BIT(s
->q
, ssh
->v2_session_id_len
);
8021 memcpy(s
->q
, ssh
->v2_session_id
,
8022 ssh
->v2_session_id_len
);
8023 s
->q
+= ssh
->v2_session_id_len
;
8024 memcpy(s
->q
, s
->pktout
->data
+ 5,
8025 s
->pktout
->length
- 5);
8026 s
->q
+= s
->pktout
->length
- 5;
8027 /* And finally the (zero) flags word. */
8029 if (!agent_query(s
->agentreq
, s
->len
+ 4,
8031 ssh_agent_callback
, ssh
)) {
8035 bombout(("Unexpected data from server"
8036 " while waiting for agent"
8040 } while (pktin
|| inlen
> 0);
8041 vret
= ssh
->agent_response
;
8042 s
->retlen
= ssh
->agent_response_len
;
8047 if (s
->ret
[4] == SSH2_AGENT_SIGN_RESPONSE
) {
8048 logevent("Sending Pageant's response");
8049 ssh2_add_sigblob(ssh
, s
->pktout
,
8050 s
->pkblob
, s
->pklen
,
8052 GET_32BIT(s
->ret
+ 5));
8053 ssh2_pkt_send(ssh
, s
->pktout
);
8054 s
->type
= AUTH_TYPE_PUBLICKEY
;
8056 /* FIXME: less drastic response */
8057 bombout(("Pageant failed to answer challenge"));
8063 /* Do we have any keys left to try? */
8064 if (s
->pkblob_in_agent
) {
8065 s
->done_agent
= TRUE
;
8066 s
->tried_pubkey_config
= TRUE
;
8069 if (s
->keyi
>= s
->nkeys
)
8070 s
->done_agent
= TRUE
;
8073 } else if (s
->can_pubkey
&& s
->publickey_blob
&&
8074 !s
->tried_pubkey_config
) {
8076 struct ssh2_userkey
*key
; /* not live over crReturn */
8077 char *passphrase
; /* not live over crReturn */
8079 ssh
->pkt_actx
= SSH2_PKTCTX_PUBLICKEY
;
8081 s
->tried_pubkey_config
= TRUE
;
8084 * Try the public key supplied in the configuration.
8086 * First, offer the public blob to see if the server is
8087 * willing to accept it.
8089 s
->pktout
= ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
8090 ssh2_pkt_addstring(s
->pktout
, ssh
->username
);
8091 ssh2_pkt_addstring(s
->pktout
, "ssh-connection");
8092 /* service requested */
8093 ssh2_pkt_addstring(s
->pktout
, "publickey"); /* method */
8094 ssh2_pkt_addbool(s
->pktout
, FALSE
);
8095 /* no signature included */
8096 ssh2_pkt_addstring(s
->pktout
, s
->publickey_algorithm
);
8097 ssh2_pkt_addstring_start(s
->pktout
);
8098 ssh2_pkt_addstring_data(s
->pktout
,
8099 (char *)s
->publickey_blob
,
8100 s
->publickey_bloblen
);
8101 ssh2_pkt_send(ssh
, s
->pktout
);
8102 logevent("Offered public key");
8104 crWaitUntilV(pktin
);
8105 if (pktin
->type
!= SSH2_MSG_USERAUTH_PK_OK
) {
8106 /* Key refused. Give up. */
8107 s
->gotit
= TRUE
; /* reconsider message next loop */
8108 s
->type
= AUTH_TYPE_PUBLICKEY_OFFER_LOUD
;
8109 continue; /* process this new message */
8111 logevent("Offer of public key accepted");
8114 * Actually attempt a serious authentication using
8117 if (flags
& FLAG_VERBOSE
) {
8118 c_write_str(ssh
, "Authenticating with public key \"");
8119 c_write_str(ssh
, s
->publickey_comment
);
8120 c_write_str(ssh
, "\"\r\n");
8124 const char *error
; /* not live over crReturn */
8125 if (s
->publickey_encrypted
) {
8127 * Get a passphrase from the user.
8129 int ret
; /* need not be kept over crReturn */
8130 s
->cur_prompt
= new_prompts(ssh
->frontend
);
8131 s
->cur_prompt
->to_server
= FALSE
;
8132 s
->cur_prompt
->name
= dupstr("SSH key passphrase");
8133 add_prompt(s
->cur_prompt
,
8134 dupprintf("Passphrase for key \"%.100s\": ",
8135 s
->publickey_comment
),
8137 ret
= get_userpass_input(s
->cur_prompt
, NULL
, 0);
8140 crWaitUntilV(!pktin
);
8141 ret
= get_userpass_input(s
->cur_prompt
,
8146 /* Failed to get a passphrase. Terminate. */
8147 free_prompts(s
->cur_prompt
);
8148 ssh_disconnect(ssh
, NULL
,
8149 "Unable to authenticate",
8150 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER
,
8155 dupstr(s
->cur_prompt
->prompts
[0]->result
);
8156 free_prompts(s
->cur_prompt
);
8158 passphrase
= NULL
; /* no passphrase needed */
8162 * Try decrypting the key.
8164 s
->keyfile
= conf_get_filename(ssh
->conf
, CONF_keyfile
);
8165 key
= ssh2_load_userkey(s
->keyfile
, passphrase
, &error
);
8167 /* burn the evidence */
8168 smemclr(passphrase
, strlen(passphrase
));
8171 if (key
== SSH2_WRONG_PASSPHRASE
|| key
== NULL
) {
8173 (key
== SSH2_WRONG_PASSPHRASE
)) {
8174 c_write_str(ssh
, "Wrong passphrase\r\n");
8176 /* and loop again */
8178 c_write_str(ssh
, "Unable to load private key (");
8179 c_write_str(ssh
, error
);
8180 c_write_str(ssh
, ")\r\n");
8182 break; /* try something else */
8188 unsigned char *pkblob
, *sigblob
, *sigdata
;
8189 int pkblob_len
, sigblob_len
, sigdata_len
;
8193 * We have loaded the private key and the server
8194 * has announced that it's willing to accept it.
8195 * Hallelujah. Generate a signature and send it.
8197 s
->pktout
= ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
8198 ssh2_pkt_addstring(s
->pktout
, ssh
->username
);
8199 ssh2_pkt_addstring(s
->pktout
, "ssh-connection");
8200 /* service requested */
8201 ssh2_pkt_addstring(s
->pktout
, "publickey");
8203 ssh2_pkt_addbool(s
->pktout
, TRUE
);
8204 /* signature follows */
8205 ssh2_pkt_addstring(s
->pktout
, key
->alg
->name
);
8206 pkblob
= key
->alg
->public_blob(key
->data
,
8208 ssh2_pkt_addstring_start(s
->pktout
);
8209 ssh2_pkt_addstring_data(s
->pktout
, (char *)pkblob
,
8213 * The data to be signed is:
8217 * followed by everything so far placed in the
8220 sigdata_len
= s
->pktout
->length
- 5 + 4 +
8221 ssh
->v2_session_id_len
;
8222 if (ssh
->remote_bugs
& BUG_SSH2_PK_SESSIONID
)
8224 sigdata
= snewn(sigdata_len
, unsigned char);
8226 if (!(ssh
->remote_bugs
& BUG_SSH2_PK_SESSIONID
)) {
8227 PUT_32BIT(sigdata
+p
, ssh
->v2_session_id_len
);
8230 memcpy(sigdata
+p
, ssh
->v2_session_id
,
8231 ssh
->v2_session_id_len
);
8232 p
+= ssh
->v2_session_id_len
;
8233 memcpy(sigdata
+p
, s
->pktout
->data
+ 5,
8234 s
->pktout
->length
- 5);
8235 p
+= s
->pktout
->length
- 5;
8236 assert(p
== sigdata_len
);
8237 sigblob
= key
->alg
->sign(key
->data
, (char *)sigdata
,
8238 sigdata_len
, &sigblob_len
);
8239 ssh2_add_sigblob(ssh
, s
->pktout
, pkblob
, pkblob_len
,
8240 sigblob
, sigblob_len
);
8245 ssh2_pkt_send(ssh
, s
->pktout
);
8246 logevent("Sent public key signature");
8247 s
->type
= AUTH_TYPE_PUBLICKEY
;
8248 key
->alg
->freekey(key
->data
);
8252 } else if (s
->can_gssapi
&& !s
->tried_gssapi
) {
8254 /* GSSAPI Authentication */
8259 s
->type
= AUTH_TYPE_GSSAPI
;
8260 s
->tried_gssapi
= TRUE
;
8262 ssh
->pkt_actx
= SSH2_PKTCTX_GSSAPI
;
8265 * Pick the highest GSS library on the preference
8271 for (i
= 0; i
< ngsslibs
; i
++) {
8272 int want_id
= conf_get_int_int(ssh
->conf
,
8273 CONF_ssh_gsslist
, i
);
8274 for (j
= 0; j
< ssh
->gsslibs
->nlibraries
; j
++)
8275 if (ssh
->gsslibs
->libraries
[j
].id
== want_id
) {
8276 s
->gsslib
= &ssh
->gsslibs
->libraries
[j
];
8277 goto got_gsslib
; /* double break */
8282 * We always expect to have found something in
8283 * the above loop: we only came here if there
8284 * was at least one viable GSS library, and the
8285 * preference list should always mention
8286 * everything and only change the order.
8291 if (s
->gsslib
->gsslogmsg
)
8292 logevent(s
->gsslib
->gsslogmsg
);
8294 /* Sending USERAUTH_REQUEST with "gssapi-with-mic" method */
8295 s
->pktout
= ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
8296 ssh2_pkt_addstring(s
->pktout
, ssh
->username
);
8297 ssh2_pkt_addstring(s
->pktout
, "ssh-connection");
8298 ssh2_pkt_addstring(s
->pktout
, "gssapi-with-mic");
8299 logevent("Attempting GSSAPI authentication");
8301 /* add mechanism info */
8302 s
->gsslib
->indicate_mech(s
->gsslib
, &s
->gss_buf
);
8304 /* number of GSSAPI mechanisms */
8305 ssh2_pkt_adduint32(s
->pktout
,1);
8307 /* length of OID + 2 */
8308 ssh2_pkt_adduint32(s
->pktout
, s
->gss_buf
.length
+ 2);
8309 ssh2_pkt_addbyte(s
->pktout
, SSH2_GSS_OIDTYPE
);
8312 ssh2_pkt_addbyte(s
->pktout
, (unsigned char) s
->gss_buf
.length
);
8314 ssh_pkt_adddata(s
->pktout
, s
->gss_buf
.value
,
8316 ssh2_pkt_send(ssh
, s
->pktout
);
8317 crWaitUntilV(pktin
);
8318 if (pktin
->type
!= SSH2_MSG_USERAUTH_GSSAPI_RESPONSE
) {
8319 logevent("GSSAPI authentication request refused");
8323 /* check returned packet ... */
8325 ssh_pkt_getstring(pktin
, &data
, &len
);
8326 s
->gss_rcvtok
.value
= data
;
8327 s
->gss_rcvtok
.length
= len
;
8328 if (s
->gss_rcvtok
.length
!= s
->gss_buf
.length
+ 2 ||
8329 ((char *)s
->gss_rcvtok
.value
)[0] != SSH2_GSS_OIDTYPE
||
8330 ((char *)s
->gss_rcvtok
.value
)[1] != s
->gss_buf
.length
||
8331 memcmp((char *)s
->gss_rcvtok
.value
+ 2,
8332 s
->gss_buf
.value
,s
->gss_buf
.length
) ) {
8333 logevent("GSSAPI authentication - wrong response from server");
8337 /* now start running */
8338 s
->gss_stat
= s
->gsslib
->import_name(s
->gsslib
,
8341 if (s
->gss_stat
!= SSH_GSS_OK
) {
8342 if (s
->gss_stat
== SSH_GSS_BAD_HOST_NAME
)
8343 logevent("GSSAPI import name failed - Bad service name");
8345 logevent("GSSAPI import name failed");
8349 /* fetch TGT into GSS engine */
8350 s
->gss_stat
= s
->gsslib
->acquire_cred(s
->gsslib
, &s
->gss_ctx
);
8352 if (s
->gss_stat
!= SSH_GSS_OK
) {
8353 logevent("GSSAPI authentication failed to get credentials");
8354 s
->gsslib
->release_name(s
->gsslib
, &s
->gss_srv_name
);
8358 /* initial tokens are empty */
8359 SSH_GSS_CLEAR_BUF(&s
->gss_rcvtok
);
8360 SSH_GSS_CLEAR_BUF(&s
->gss_sndtok
);
8362 /* now enter the loop */
8364 s
->gss_stat
= s
->gsslib
->init_sec_context
8368 conf_get_int(ssh
->conf
, CONF_gssapifwd
),
8372 if (s
->gss_stat
!=SSH_GSS_S_COMPLETE
&&
8373 s
->gss_stat
!=SSH_GSS_S_CONTINUE_NEEDED
) {
8374 logevent("GSSAPI authentication initialisation failed");
8376 if (s
->gsslib
->display_status(s
->gsslib
, s
->gss_ctx
,
8377 &s
->gss_buf
) == SSH_GSS_OK
) {
8378 logevent(s
->gss_buf
.value
);
8379 sfree(s
->gss_buf
.value
);
8384 logevent("GSSAPI authentication initialised");
8386 /* Client and server now exchange tokens until GSSAPI
8387 * no longer says CONTINUE_NEEDED */
8389 if (s
->gss_sndtok
.length
!= 0) {
8390 s
->pktout
= ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_TOKEN
);
8391 ssh_pkt_addstring_start(s
->pktout
);
8392 ssh_pkt_addstring_data(s
->pktout
,s
->gss_sndtok
.value
,s
->gss_sndtok
.length
);
8393 ssh2_pkt_send(ssh
, s
->pktout
);
8394 s
->gsslib
->free_tok(s
->gsslib
, &s
->gss_sndtok
);
8397 if (s
->gss_stat
== SSH_GSS_S_CONTINUE_NEEDED
) {
8398 crWaitUntilV(pktin
);
8399 if (pktin
->type
!= SSH2_MSG_USERAUTH_GSSAPI_TOKEN
) {
8400 logevent("GSSAPI authentication - bad server response");
8401 s
->gss_stat
= SSH_GSS_FAILURE
;
8404 ssh_pkt_getstring(pktin
, &data
, &len
);
8405 s
->gss_rcvtok
.value
= data
;
8406 s
->gss_rcvtok
.length
= len
;
8408 } while (s
-> gss_stat
== SSH_GSS_S_CONTINUE_NEEDED
);
8410 if (s
->gss_stat
!= SSH_GSS_OK
) {
8411 s
->gsslib
->release_name(s
->gsslib
, &s
->gss_srv_name
);
8412 s
->gsslib
->release_cred(s
->gsslib
, &s
->gss_ctx
);
8415 logevent("GSSAPI authentication loop finished OK");
8417 /* Now send the MIC */
8419 s
->pktout
= ssh2_pkt_init(0);
8420 micoffset
= s
->pktout
->length
;
8421 ssh_pkt_addstring_start(s
->pktout
);
8422 ssh_pkt_addstring_data(s
->pktout
, (char *)ssh
->v2_session_id
, ssh
->v2_session_id_len
);
8423 ssh_pkt_addbyte(s
->pktout
, SSH2_MSG_USERAUTH_REQUEST
);
8424 ssh_pkt_addstring(s
->pktout
, ssh
->username
);
8425 ssh_pkt_addstring(s
->pktout
, "ssh-connection");
8426 ssh_pkt_addstring(s
->pktout
, "gssapi-with-mic");
8428 s
->gss_buf
.value
= (char *)s
->pktout
->data
+ micoffset
;
8429 s
->gss_buf
.length
= s
->pktout
->length
- micoffset
;
8431 s
->gsslib
->get_mic(s
->gsslib
, s
->gss_ctx
, &s
->gss_buf
, &mic
);
8432 s
->pktout
= ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_MIC
);
8433 ssh_pkt_addstring_start(s
->pktout
);
8434 ssh_pkt_addstring_data(s
->pktout
, mic
.value
, mic
.length
);
8435 ssh2_pkt_send(ssh
, s
->pktout
);
8436 s
->gsslib
->free_mic(s
->gsslib
, &mic
);
8440 s
->gsslib
->release_name(s
->gsslib
, &s
->gss_srv_name
);
8441 s
->gsslib
->release_cred(s
->gsslib
, &s
->gss_ctx
);
8444 } else if (s
->can_keyb_inter
&& !s
->kbd_inter_refused
) {
8447 * Keyboard-interactive authentication.
8450 s
->type
= AUTH_TYPE_KEYBOARD_INTERACTIVE
;
8452 ssh
->pkt_actx
= SSH2_PKTCTX_KBDINTER
;
8454 s
->pktout
= ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
8455 ssh2_pkt_addstring(s
->pktout
, ssh
->username
);
8456 ssh2_pkt_addstring(s
->pktout
, "ssh-connection");
8457 /* service requested */
8458 ssh2_pkt_addstring(s
->pktout
, "keyboard-interactive");
8460 ssh2_pkt_addstring(s
->pktout
, ""); /* lang */
8461 ssh2_pkt_addstring(s
->pktout
, ""); /* submethods */
8462 ssh2_pkt_send(ssh
, s
->pktout
);
8464 logevent("Attempting keyboard-interactive authentication");
8466 crWaitUntilV(pktin
);
8467 if (pktin
->type
!= SSH2_MSG_USERAUTH_INFO_REQUEST
) {
8468 /* Server is not willing to do keyboard-interactive
8469 * at all (or, bizarrely but legally, accepts the
8470 * user without actually issuing any prompts).
8471 * Give up on it entirely. */
8473 s
->type
= AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
;
8474 s
->kbd_inter_refused
= TRUE
; /* don't try it again */
8479 * Loop while the server continues to send INFO_REQUESTs.
8481 while (pktin
->type
== SSH2_MSG_USERAUTH_INFO_REQUEST
) {
8483 char *name
, *inst
, *lang
;
8484 int name_len
, inst_len
, lang_len
;
8488 * We've got a fresh USERAUTH_INFO_REQUEST.
8489 * Get the preamble and start building a prompt.
8491 ssh_pkt_getstring(pktin
, &name
, &name_len
);
8492 ssh_pkt_getstring(pktin
, &inst
, &inst_len
);
8493 ssh_pkt_getstring(pktin
, &lang
, &lang_len
);
8494 s
->cur_prompt
= new_prompts(ssh
->frontend
);
8495 s
->cur_prompt
->to_server
= TRUE
;
8498 * Get any prompt(s) from the packet.
8500 s
->num_prompts
= ssh_pkt_getuint32(pktin
);
8501 for (i
= 0; i
< s
->num_prompts
; i
++) {
8505 static char noprompt
[] =
8506 "<server failed to send prompt>: ";
8508 ssh_pkt_getstring(pktin
, &prompt
, &prompt_len
);
8509 echo
= ssh2_pkt_getbool(pktin
);
8512 prompt_len
= lenof(noprompt
)-1;
8514 add_prompt(s
->cur_prompt
,
8515 dupprintf("%.*s", prompt_len
, prompt
),
8520 /* FIXME: better prefix to distinguish from
8522 s
->cur_prompt
->name
=
8523 dupprintf("SSH server: %.*s", name_len
, name
);
8524 s
->cur_prompt
->name_reqd
= TRUE
;
8526 s
->cur_prompt
->name
=
8527 dupstr("SSH server authentication");
8528 s
->cur_prompt
->name_reqd
= FALSE
;
8530 /* We add a prefix to try to make it clear that a prompt
8531 * has come from the server.
8532 * FIXME: ugly to print "Using..." in prompt _every_
8533 * time round. Can this be done more subtly? */
8534 /* Special case: for reasons best known to themselves,
8535 * some servers send k-i requests with no prompts and
8536 * nothing to display. Keep quiet in this case. */
8537 if (s
->num_prompts
|| name_len
|| inst_len
) {
8538 s
->cur_prompt
->instruction
=
8539 dupprintf("Using keyboard-interactive authentication.%s%.*s",
8540 inst_len ?
"\n" : "", inst_len
, inst
);
8541 s
->cur_prompt
->instr_reqd
= TRUE
;
8543 s
->cur_prompt
->instr_reqd
= FALSE
;
8547 * Display any instructions, and get the user's
8551 int ret
; /* not live over crReturn */
8552 ret
= get_userpass_input(s
->cur_prompt
, NULL
, 0);
8555 crWaitUntilV(!pktin
);
8556 ret
= get_userpass_input(s
->cur_prompt
, in
, inlen
);
8561 * Failed to get responses. Terminate.
8563 free_prompts(s
->cur_prompt
);
8564 ssh_disconnect(ssh
, NULL
, "Unable to authenticate",
8565 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER
,
8572 * Send the response(s) to the server.
8574 s
->pktout
= ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE
);
8575 ssh2_pkt_adduint32(s
->pktout
, s
->num_prompts
);
8576 for (i
=0; i
< s
->num_prompts
; i
++) {
8577 dont_log_password(ssh
, s
->pktout
, PKTLOG_BLANK
);
8578 ssh2_pkt_addstring(s
->pktout
,
8579 s
->cur_prompt
->prompts
[i
]->result
);
8580 end_log_omission(ssh
, s
->pktout
);
8582 ssh2_pkt_send_with_padding(ssh
, s
->pktout
, 256);
8585 * Free the prompts structure from this iteration.
8586 * If there's another, a new one will be allocated
8587 * when we return to the top of this while loop.
8589 free_prompts(s
->cur_prompt
);
8592 * Get the next packet in case it's another
8595 crWaitUntilV(pktin
);
8600 * We should have SUCCESS or FAILURE now.
8604 } else if (s
->can_passwd
) {
8607 * Plain old password authentication.
8609 int ret
; /* not live over crReturn */
8610 int changereq_first_time
; /* not live over crReturn */
8612 ssh
->pkt_actx
= SSH2_PKTCTX_PASSWORD
;
8614 s
->cur_prompt
= new_prompts(ssh
->frontend
);
8615 s
->cur_prompt
->to_server
= TRUE
;
8616 s
->cur_prompt
->name
= dupstr("SSH password");
8617 add_prompt(s
->cur_prompt
, dupprintf("%s@%s's password: ",
8622 ret
= get_userpass_input(s
->cur_prompt
, NULL
, 0);
8625 crWaitUntilV(!pktin
);
8626 ret
= get_userpass_input(s
->cur_prompt
, in
, inlen
);
8631 * Failed to get responses. Terminate.
8633 free_prompts(s
->cur_prompt
);
8634 ssh_disconnect(ssh
, NULL
, "Unable to authenticate",
8635 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER
,
8640 * Squirrel away the password. (We may need it later if
8641 * asked to change it.)
8643 s
->password
= dupstr(s
->cur_prompt
->prompts
[0]->result
);
8644 free_prompts(s
->cur_prompt
);
8647 * Send the password packet.
8649 * We pad out the password packet to 256 bytes to make
8650 * it harder for an attacker to find the length of the
8653 * Anyone using a password longer than 256 bytes
8654 * probably doesn't have much to worry about from
8655 * people who find out how long their password is!
8657 s
->pktout
= ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
8658 ssh2_pkt_addstring(s
->pktout
, ssh
->username
);
8659 ssh2_pkt_addstring(s
->pktout
, "ssh-connection");
8660 /* service requested */
8661 ssh2_pkt_addstring(s
->pktout
, "password");
8662 ssh2_pkt_addbool(s
->pktout
, FALSE
);
8663 dont_log_password(ssh
, s
->pktout
, PKTLOG_BLANK
);
8664 ssh2_pkt_addstring(s
->pktout
, s
->password
);
8665 end_log_omission(ssh
, s
->pktout
);
8666 ssh2_pkt_send_with_padding(ssh
, s
->pktout
, 256);
8667 logevent("Sent password");
8668 s
->type
= AUTH_TYPE_PASSWORD
;
8671 * Wait for next packet, in case it's a password change
8674 crWaitUntilV(pktin
);
8675 changereq_first_time
= TRUE
;
8677 while (pktin
->type
== SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ
) {
8680 * We're being asked for a new password
8681 * (perhaps not for the first time).
8682 * Loop until the server accepts it.
8685 int got_new
= FALSE
; /* not live over crReturn */
8686 char *prompt
; /* not live over crReturn */
8687 int prompt_len
; /* not live over crReturn */
8691 if (changereq_first_time
)
8692 msg
= "Server requested password change";
8694 msg
= "Server rejected new password";
8696 c_write_str(ssh
, msg
);
8697 c_write_str(ssh
, "\r\n");
8700 ssh_pkt_getstring(pktin
, &prompt
, &prompt_len
);
8702 s
->cur_prompt
= new_prompts(ssh
->frontend
);
8703 s
->cur_prompt
->to_server
= TRUE
;
8704 s
->cur_prompt
->name
= dupstr("New SSH password");
8705 s
->cur_prompt
->instruction
=
8706 dupprintf("%.*s", prompt_len
, prompt
);
8707 s
->cur_prompt
->instr_reqd
= TRUE
;
8709 * There's no explicit requirement in the protocol
8710 * for the "old" passwords in the original and
8711 * password-change messages to be the same, and
8712 * apparently some Cisco kit supports password change
8713 * by the user entering a blank password originally
8714 * and the real password subsequently, so,
8715 * reluctantly, we prompt for the old password again.
8717 * (On the other hand, some servers don't even bother
8718 * to check this field.)
8720 add_prompt(s
->cur_prompt
,
8721 dupstr("Current password (blank for previously entered password): "),
8723 add_prompt(s
->cur_prompt
, dupstr("Enter new password: "),
8725 add_prompt(s
->cur_prompt
, dupstr("Confirm new password: "),
8729 * Loop until the user manages to enter the same
8734 ret
= get_userpass_input(s
->cur_prompt
, NULL
, 0);
8737 crWaitUntilV(!pktin
);
8738 ret
= get_userpass_input(s
->cur_prompt
, in
, inlen
);
8743 * Failed to get responses. Terminate.
8745 /* burn the evidence */
8746 free_prompts(s
->cur_prompt
);
8747 smemclr(s
->password
, strlen(s
->password
));
8749 ssh_disconnect(ssh
, NULL
, "Unable to authenticate",
8750 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER
,
8756 * If the user specified a new original password
8757 * (IYSWIM), overwrite any previously specified
8759 * (A side effect is that the user doesn't have to
8760 * re-enter it if they louse up the new password.)
8762 if (s
->cur_prompt
->prompts
[0]->result
[0]) {
8763 smemclr(s
->password
, strlen(s
->password
));
8764 /* burn the evidence */
8767 dupstr(s
->cur_prompt
->prompts
[0]->result
);
8771 * Check the two new passwords match.
8773 got_new
= (strcmp(s
->cur_prompt
->prompts
[1]->result
,
8774 s
->cur_prompt
->prompts
[2]->result
)
8777 /* They don't. Silly user. */
8778 c_write_str(ssh
, "Passwords do not match\r\n");
8783 * Send the new password (along with the old one).
8784 * (see above for padding rationale)
8786 s
->pktout
= ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
8787 ssh2_pkt_addstring(s
->pktout
, ssh
->username
);
8788 ssh2_pkt_addstring(s
->pktout
, "ssh-connection");
8789 /* service requested */
8790 ssh2_pkt_addstring(s
->pktout
, "password");
8791 ssh2_pkt_addbool(s
->pktout
, TRUE
);
8792 dont_log_password(ssh
, s
->pktout
, PKTLOG_BLANK
);
8793 ssh2_pkt_addstring(s
->pktout
, s
->password
);
8794 ssh2_pkt_addstring(s
->pktout
,
8795 s
->cur_prompt
->prompts
[1]->result
);
8796 free_prompts(s
->cur_prompt
);
8797 end_log_omission(ssh
, s
->pktout
);
8798 ssh2_pkt_send_with_padding(ssh
, s
->pktout
, 256);
8799 logevent("Sent new password");
8802 * Now see what the server has to say about it.
8803 * (If it's CHANGEREQ again, it's not happy with the
8806 crWaitUntilV(pktin
);
8807 changereq_first_time
= FALSE
;
8812 * We need to reexamine the current pktin at the top
8813 * of the loop. Either:
8814 * - we weren't asked to change password at all, in
8815 * which case it's a SUCCESS or FAILURE with the
8817 * - we sent a new password, and the server was
8818 * either OK with it (SUCCESS or FAILURE w/partial
8819 * success) or unhappy with the _old_ password
8820 * (FAILURE w/o partial success)
8821 * In any of these cases, we go back to the top of
8822 * the loop and start again.
8827 * We don't need the old password any more, in any
8828 * case. Burn the evidence.
8830 smemclr(s
->password
, strlen(s
->password
));
8834 char *str
= dupprintf("No supported authentication methods available"
8835 " (server sent: %.*s)",
8838 ssh_disconnect(ssh
, str
,
8839 "No supported authentication methods available",
8840 SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE
,
8850 ssh
->packet_dispatch
[SSH2_MSG_USERAUTH_BANNER
] = NULL
;
8852 /* Clear up various bits and pieces from authentication. */
8853 if (s
->publickey_blob
) {
8854 sfree(s
->publickey_blob
);
8855 sfree(s
->publickey_comment
);
8857 if (s
->agent_response
)
8858 sfree(s
->agent_response
);
8860 if (s
->userauth_success
) {
8862 * We've just received USERAUTH_SUCCESS, and we haven't sent any
8863 * packets since. Signal the transport layer to consider enacting
8864 * delayed compression.
8866 * (Relying on we_are_in is not sufficient, as
8867 * draft-miller-secsh-compression-delayed is quite clear that it
8868 * triggers on USERAUTH_SUCCESS specifically, and we_are_in can
8869 * become set for other reasons.)
8871 do_ssh2_transport(ssh
, "enabling delayed compression", -2, NULL
);
8875 * Now the connection protocol has started, one way or another.
8878 ssh
->channels
= newtree234(ssh_channelcmp
);
8881 * Set up handlers for some connection protocol messages, so we
8882 * don't have to handle them repeatedly in this coroutine.
8884 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_WINDOW_ADJUST
] =
8885 ssh2_msg_channel_window_adjust
;
8886 ssh
->packet_dispatch
[SSH2_MSG_GLOBAL_REQUEST
] =
8887 ssh2_msg_global_request
;
8890 * Create the main session channel.
8892 if (conf_get_int(ssh
->conf
, CONF_ssh_no_shell
)) {
8893 ssh
->mainchan
= NULL
;
8894 } else if (*conf_get_str(ssh
->conf
, CONF_ssh_nc_host
)) {
8896 * Just start a direct-tcpip channel and use it as the main
8899 ssh
->mainchan
= snew(struct ssh_channel
);
8900 ssh
->mainchan
->ssh
= ssh
;
8901 ssh2_channel_init(ssh
->mainchan
);
8903 "Opening direct-tcpip channel to %s:%d in place of session",
8904 conf_get_str(ssh
->conf
, CONF_ssh_nc_host
),
8905 conf_get_int(ssh
->conf
, CONF_ssh_nc_port
));
8906 s
->pktout
= ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN
);
8907 ssh2_pkt_addstring(s
->pktout
, "direct-tcpip");
8908 ssh2_pkt_adduint32(s
->pktout
, ssh
->mainchan
->localid
);
8909 ssh2_pkt_adduint32(s
->pktout
, ssh
->mainchan
->v
.v2
.locwindow
);/* our window size */
8910 ssh2_pkt_adduint32(s
->pktout
, OUR_V2_MAXPKT
); /* our max pkt size */
8911 ssh2_pkt_addstring(s
->pktout
, conf_get_str(ssh
->conf
, CONF_ssh_nc_host
));
8912 ssh2_pkt_adduint32(s
->pktout
, conf_get_int(ssh
->conf
, CONF_ssh_nc_port
));
8914 * There's nothing meaningful to put in the originator
8915 * fields, but some servers insist on syntactically correct
8918 ssh2_pkt_addstring(s
->pktout
, "0.0.0.0");
8919 ssh2_pkt_adduint32(s
->pktout
, 0);
8920 ssh2_pkt_send(ssh
, s
->pktout
);
8922 crWaitUntilV(pktin
);
8923 if (pktin
->type
!= SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
) {
8924 bombout(("Server refused to open a direct-tcpip channel"));
8926 /* FIXME: error data comes back in FAILURE packet */
8928 if (ssh_pkt_getuint32(pktin
) != ssh
->mainchan
->localid
) {
8929 bombout(("Server's channel confirmation cited wrong channel"));
8932 ssh
->mainchan
->remoteid
= ssh_pkt_getuint32(pktin
);
8933 ssh
->mainchan
->halfopen
= FALSE
;
8934 ssh
->mainchan
->type
= CHAN_MAINSESSION
;
8935 ssh
->mainchan
->v
.v2
.remwindow
= ssh_pkt_getuint32(pktin
);
8936 ssh
->mainchan
->v
.v2
.remmaxpkt
= ssh_pkt_getuint32(pktin
);
8937 add234(ssh
->channels
, ssh
->mainchan
);
8938 update_specials_menu(ssh
->frontend
);
8939 logevent("Opened direct-tcpip channel");
8942 ssh
->mainchan
= snew(struct ssh_channel
);
8943 ssh
->mainchan
->ssh
= ssh
;
8944 ssh2_channel_init(ssh
->mainchan
);
8945 s
->pktout
= ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN
);
8946 ssh2_pkt_addstring(s
->pktout
, "session");
8947 ssh2_pkt_adduint32(s
->pktout
, ssh
->mainchan
->localid
);
8948 ssh2_pkt_adduint32(s
->pktout
, ssh
->mainchan
->v
.v2
.locwindow
);/* our window size */
8949 ssh2_pkt_adduint32(s
->pktout
, OUR_V2_MAXPKT
); /* our max pkt size */
8950 ssh2_pkt_send(ssh
, s
->pktout
);
8951 crWaitUntilV(pktin
);
8952 if (pktin
->type
!= SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
) {
8953 bombout(("Server refused to open a session"));
8955 /* FIXME: error data comes back in FAILURE packet */
8957 if (ssh_pkt_getuint32(pktin
) != ssh
->mainchan
->localid
) {
8958 bombout(("Server's channel confirmation cited wrong channel"));
8961 ssh
->mainchan
->remoteid
= ssh_pkt_getuint32(pktin
);
8962 ssh
->mainchan
->halfopen
= FALSE
;
8963 ssh
->mainchan
->type
= CHAN_MAINSESSION
;
8964 ssh
->mainchan
->v
.v2
.remwindow
= ssh_pkt_getuint32(pktin
);
8965 ssh
->mainchan
->v
.v2
.remmaxpkt
= ssh_pkt_getuint32(pktin
);
8966 add234(ssh
->channels
, ssh
->mainchan
);
8967 update_specials_menu(ssh
->frontend
);
8968 logevent("Opened channel for session");
8969 ssh
->ncmode
= FALSE
;
8973 * Now we have a channel, make dispatch table entries for
8974 * general channel-based messages.
8976 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_DATA
] =
8977 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_EXTENDED_DATA
] =
8978 ssh2_msg_channel_data
;
8979 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_EOF
] = ssh2_msg_channel_eof
;
8980 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_CLOSE
] = ssh2_msg_channel_close
;
8981 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
] =
8982 ssh2_msg_channel_open_confirmation
;
8983 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_OPEN_FAILURE
] =
8984 ssh2_msg_channel_open_failure
;
8985 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_REQUEST
] =
8986 ssh2_msg_channel_request
;
8987 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_OPEN
] =
8988 ssh2_msg_channel_open
;
8990 if (ssh
->mainchan
&& conf_get_int(ssh
->conf
, CONF_ssh_simple
)) {
8992 * This message indicates to the server that we promise
8993 * not to try to run any other channel in parallel with
8994 * this one, so it's safe for it to advertise a very large
8995 * window and leave the flow control to TCP.
8997 s
->pktout
= ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
8998 ssh2_pkt_adduint32(s
->pktout
, ssh
->mainchan
->remoteid
);
8999 ssh2_pkt_addstring(s
->pktout
, "simple@putty.projects.tartarus.org");
9000 ssh2_pkt_addbool(s
->pktout
, 0); /* no reply */
9001 ssh2_pkt_send(ssh
, s
->pktout
);
9005 * Enable port forwardings.
9007 ssh_setup_portfwd(ssh
, ssh
->conf
);
9010 * Send the CHANNEL_REQUESTS for the main channel. We send them all
9011 * and then start looking for responses, so it's important that the
9012 * sending and receiving code below it is kept in sync.
9016 * Potentially enable X11 forwarding.
9018 if (ssh
->mainchan
&& !ssh
->ncmode
&& conf_get_int(ssh
->conf
, CONF_x11_forward
) &&
9019 (ssh
->x11disp
= x11_setup_display(conf_get_str(ssh
->conf
, CONF_x11_display
),
9020 conf_get_int(ssh
->conf
, CONF_x11_auth
), ssh
->conf
))) {
9021 logevent("Requesting X11 forwarding");
9022 s
->pktout
= ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
9023 ssh2_pkt_adduint32(s
->pktout
, ssh
->mainchan
->remoteid
);
9024 ssh2_pkt_addstring(s
->pktout
, "x11-req");
9025 ssh2_pkt_addbool(s
->pktout
, 1); /* want reply */
9026 ssh2_pkt_addbool(s
->pktout
, 0); /* many connections */
9027 ssh2_pkt_addstring(s
->pktout
, ssh
->x11disp
->remoteauthprotoname
);
9029 * Note that while we blank the X authentication data here, we don't
9030 * take any special action to blank the start of an X11 channel,
9031 * so using MIT-MAGIC-COOKIE-1 and actually opening an X connection
9032 * without having session blanking enabled is likely to leak your
9033 * cookie into the log.
9035 dont_log_password(ssh
, s
->pktout
, PKTLOG_BLANK
);
9036 ssh2_pkt_addstring(s
->pktout
, ssh
->x11disp
->remoteauthdatastring
);
9037 end_log_omission(ssh
, s
->pktout
);
9038 ssh2_pkt_adduint32(s
->pktout
, ssh
->x11disp
->screennum
);
9039 ssh2_pkt_send(ssh
, s
->pktout
);
9040 s
->requested_x11
= TRUE
;
9042 s
->requested_x11
= FALSE
;
9045 * Potentially enable agent forwarding.
9047 if (ssh
->mainchan
&& !ssh
->ncmode
&& conf_get_int(ssh
->conf
, CONF_agentfwd
) && agent_exists()) {
9048 logevent("Requesting OpenSSH-style agent forwarding");
9049 s
->pktout
= ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
9050 ssh2_pkt_adduint32(s
->pktout
, ssh
->mainchan
->remoteid
);
9051 ssh2_pkt_addstring(s
->pktout
, "auth-agent-req@openssh.com");
9052 ssh2_pkt_addbool(s
->pktout
, 1); /* want reply */
9053 ssh2_pkt_send(ssh
, s
->pktout
);
9054 s
->requested_agent
= TRUE
;
9056 s
->requested_agent
= FALSE
;
9059 * Now allocate a pty for the session.
9061 if (ssh
->mainchan
&& !ssh
->ncmode
&& !conf_get_int(ssh
->conf
, CONF_nopty
)) {
9062 /* Unpick the terminal-speed string. */
9063 /* XXX perhaps we should allow no speeds to be sent. */
9064 ssh
->ospeed
= 38400; ssh
->ispeed
= 38400; /* last-resort defaults */
9065 sscanf(conf_get_str(ssh
->conf
, CONF_termspeed
), "%d,%d", &ssh
->ospeed
, &ssh
->ispeed
);
9066 /* Build the pty request. */
9067 s
->pktout
= ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
9068 ssh2_pkt_adduint32(s
->pktout
, ssh
->mainchan
->remoteid
); /* recipient channel */
9069 ssh2_pkt_addstring(s
->pktout
, "pty-req");
9070 ssh2_pkt_addbool(s
->pktout
, 1); /* want reply */
9071 ssh2_pkt_addstring(s
->pktout
, conf_get_str(ssh
->conf
, CONF_termtype
));
9072 ssh2_pkt_adduint32(s
->pktout
, ssh
->term_width
);
9073 ssh2_pkt_adduint32(s
->pktout
, ssh
->term_height
);
9074 ssh2_pkt_adduint32(s
->pktout
, 0); /* pixel width */
9075 ssh2_pkt_adduint32(s
->pktout
, 0); /* pixel height */
9076 ssh2_pkt_addstring_start(s
->pktout
);
9077 parse_ttymodes(ssh
, ssh2_send_ttymode
, (void *)s
->pktout
);
9078 ssh2_pkt_addbyte(s
->pktout
, SSH2_TTY_OP_ISPEED
);
9079 ssh2_pkt_adduint32(s
->pktout
, ssh
->ispeed
);
9080 ssh2_pkt_addbyte(s
->pktout
, SSH2_TTY_OP_OSPEED
);
9081 ssh2_pkt_adduint32(s
->pktout
, ssh
->ospeed
);
9082 ssh2_pkt_addstring_data(s
->pktout
, "\0", 1); /* TTY_OP_END */
9083 ssh2_pkt_send(ssh
, s
->pktout
);
9084 ssh
->state
= SSH_STATE_INTERMED
;
9085 s
->requested_tty
= TRUE
;
9087 s
->requested_tty
= FALSE
;
9090 * Send environment variables.
9092 * Simplest thing here is to send all the requests at once, and
9093 * then wait for a whole bunch of successes or failures.
9096 if (ssh
->mainchan
&& !ssh
->ncmode
) {
9099 for (val
= conf_get_str_strs(ssh
->conf
, CONF_environmt
, NULL
, &key
);
9101 val
= conf_get_str_strs(ssh
->conf
, CONF_environmt
, key
, &key
)) {
9102 s
->pktout
= ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
9103 ssh2_pkt_adduint32(s
->pktout
, ssh
->mainchan
->remoteid
);
9104 ssh2_pkt_addstring(s
->pktout
, "env");
9105 ssh2_pkt_addbool(s
->pktout
, 1); /* want reply */
9106 ssh2_pkt_addstring(s
->pktout
, key
);
9107 ssh2_pkt_addstring(s
->pktout
, val
);
9108 ssh2_pkt_send(ssh
, s
->pktout
);
9113 logeventf(ssh
, "Sent %d environment variables", s
->num_env
);
9117 * All CHANNEL_REQUESTs sent. Now collect up the replies. These
9118 * must be in precisely the same order as the requests.
9121 if (s
->requested_x11
) {
9122 crWaitUntilV(pktin
);
9124 if (pktin
->type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
9125 if (pktin
->type
!= SSH2_MSG_CHANNEL_FAILURE
) {
9126 bombout(("Unexpected response to X11 forwarding request:"
9127 " packet type %d", pktin
->type
));
9130 logevent("X11 forwarding refused");
9132 logevent("X11 forwarding enabled");
9133 ssh
->X11_fwd_enabled
= TRUE
;
9137 if (s
->requested_agent
) {
9138 crWaitUntilV(pktin
);
9140 if (pktin
->type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
9141 if (pktin
->type
!= SSH2_MSG_CHANNEL_FAILURE
) {
9142 bombout(("Unexpected response to agent forwarding request:"
9143 " packet type %d", pktin
->type
));
9146 logevent("Agent forwarding refused");
9148 logevent("Agent forwarding enabled");
9149 ssh
->agentfwd_enabled
= TRUE
;
9153 if (s
->requested_tty
) {
9154 crWaitUntilV(pktin
);
9156 if (pktin
->type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
9157 if (pktin
->type
!= SSH2_MSG_CHANNEL_FAILURE
) {
9158 bombout(("Unexpected response to pty request:"
9159 " packet type %d", pktin
->type
));
9162 c_write_str(ssh
, "Server refused to allocate pty\r\n");
9163 ssh
->editing
= ssh
->echoing
= 1;
9165 logeventf(ssh
, "Allocated pty (ospeed %dbps, ispeed %dbps)",
9166 ssh
->ospeed
, ssh
->ispeed
);
9167 ssh
->got_pty
= TRUE
;
9170 ssh
->editing
= ssh
->echoing
= 1;
9175 s
->env_left
= s
->num_env
;
9177 while (s
->env_left
> 0) {
9178 crWaitUntilV(pktin
);
9180 if (pktin
->type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
9181 if (pktin
->type
!= SSH2_MSG_CHANNEL_FAILURE
) {
9182 bombout(("Unexpected response to environment request:"
9183 " packet type %d", pktin
->type
));
9193 if (s
->env_ok
== s
->num_env
) {
9194 logevent("All environment variables successfully set");
9195 } else if (s
->env_ok
== 0) {
9196 logevent("All environment variables refused");
9197 c_write_str(ssh
, "Server refused to set environment variables\r\n");
9199 logeventf(ssh
, "%d environment variables refused",
9200 s
->num_env
- s
->env_ok
);
9201 c_write_str(ssh
, "Server refused to set all environment variables\r\n");
9206 * Start a shell or a remote command. We may have to attempt
9207 * this twice if the config data has provided a second choice
9210 if (ssh
->mainchan
&& !ssh
->ncmode
) while (1) {
9214 if (ssh
->fallback_cmd
) {
9215 subsys
= conf_get_int(ssh
->conf
, CONF_ssh_subsys2
);
9216 cmd
= conf_get_str(ssh
->conf
, CONF_remote_cmd2
);
9218 subsys
= conf_get_int(ssh
->conf
, CONF_ssh_subsys
);
9219 cmd
= conf_get_str(ssh
->conf
, CONF_remote_cmd
);
9222 s
->pktout
= ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
9223 ssh2_pkt_adduint32(s
->pktout
, ssh
->mainchan
->remoteid
); /* recipient channel */
9225 ssh2_pkt_addstring(s
->pktout
, "subsystem");
9226 ssh2_pkt_addbool(s
->pktout
, 1); /* want reply */
9227 ssh2_pkt_addstring(s
->pktout
, cmd
);
9229 ssh2_pkt_addstring(s
->pktout
, "exec");
9230 ssh2_pkt_addbool(s
->pktout
, 1); /* want reply */
9231 ssh2_pkt_addstring(s
->pktout
, cmd
);
9233 ssh2_pkt_addstring(s
->pktout
, "shell");
9234 ssh2_pkt_addbool(s
->pktout
, 1); /* want reply */
9236 ssh2_pkt_send(ssh
, s
->pktout
);
9238 crWaitUntilV(pktin
);
9240 if (pktin
->type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
9241 if (pktin
->type
!= SSH2_MSG_CHANNEL_FAILURE
) {
9242 bombout(("Unexpected response to shell/command request:"
9243 " packet type %d", pktin
->type
));
9247 * We failed to start the command. If this is the
9248 * fallback command, we really are finished; if it's
9249 * not, and if the fallback command exists, try falling
9250 * back to it before complaining.
9252 if (!ssh
->fallback_cmd
&&
9253 *conf_get_str(ssh
->conf
, CONF_remote_cmd2
)) {
9254 logevent("Primary command failed; attempting fallback");
9255 ssh
->fallback_cmd
= TRUE
;
9258 bombout(("Server refused to start a shell/command"));
9261 logevent("Started a shell/command");
9266 ssh
->state
= SSH_STATE_SESSION
;
9267 if (ssh
->size_needed
)
9268 ssh_size(ssh
, ssh
->term_width
, ssh
->term_height
);
9269 if (ssh
->eof_needed
)
9270 ssh_special(ssh
, TS_EOF
);
9273 * All the initial channel requests are done, so install the default
9276 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_SUCCESS
] = ssh2_msg_channel_success
;
9277 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_FAILURE
] = ssh2_msg_channel_failure
;
9283 ldisc_send(ssh
->ldisc
, NULL
, 0, 0);/* cause ldisc to notice changes */
9288 s
->try_send
= FALSE
;
9292 * _All_ the connection-layer packets we expect to
9293 * receive are now handled by the dispatch table.
9294 * Anything that reaches here must be bogus.
9297 bombout(("Strange packet received: type %d", pktin
->type
));
9299 } else if (ssh
->mainchan
) {
9301 * We have spare data. Add it to the channel buffer.
9303 ssh2_add_channel_data(ssh
->mainchan
, (char *)in
, inlen
);
9308 struct ssh_channel
*c
;
9310 * Try to send data on all channels if we can.
9312 for (i
= 0; NULL
!= (c
= index234(ssh
->channels
, i
)); i
++)
9313 ssh2_try_send_and_unthrottle(ssh
, c
);
9321 * Handlers for SSH-2 messages that might arrive at any moment.
9323 static void ssh2_msg_disconnect(Ssh ssh
, struct Packet
*pktin
)
9325 /* log reason code in disconnect message */
9329 reason
= ssh_pkt_getuint32(pktin
);
9330 ssh_pkt_getstring(pktin
, &msg
, &msglen
);
9332 if (reason
> 0 && reason
< lenof(ssh2_disconnect_reasons
)) {
9333 buf
= dupprintf("Received disconnect message (%s)",
9334 ssh2_disconnect_reasons
[reason
]);
9336 buf
= dupprintf("Received disconnect message (unknown"
9337 " type %d)", reason
);
9341 buf
= dupprintf("Disconnection message text: %.*s",
9344 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%.*s\"",
9346 (reason
> 0 && reason
< lenof(ssh2_disconnect_reasons
)) ?
9347 ssh2_disconnect_reasons
[reason
] : "unknown",
9352 static void ssh2_msg_debug(Ssh ssh
, struct Packet
*pktin
)
9354 /* log the debug message */
9358 /* XXX maybe we should actually take notice of the return value */
9359 ssh2_pkt_getbool(pktin
);
9360 ssh_pkt_getstring(pktin
, &msg
, &msglen
);
9362 logeventf(ssh
, "Remote debug message: %.*s", msglen
, msg
);
9365 static void ssh2_msg_something_unimplemented(Ssh ssh
, struct Packet
*pktin
)
9367 struct Packet
*pktout
;
9368 pktout
= ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED
);
9369 ssh2_pkt_adduint32(pktout
, pktin
->sequence
);
9371 * UNIMPLEMENTED messages MUST appear in the same order as the
9372 * messages they respond to. Hence, never queue them.
9374 ssh2_pkt_send_noqueue(ssh
, pktout
);
9378 * Handle the top-level SSH-2 protocol.
9380 static void ssh2_protocol_setup(Ssh ssh
)
9385 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
9387 for (i
= 0; i
< 256; i
++)
9388 ssh
->packet_dispatch
[i
] = ssh2_msg_something_unimplemented
;
9391 * Any message we actually understand, we set to NULL so that
9392 * the coroutines will get it.
9394 ssh
->packet_dispatch
[SSH2_MSG_UNIMPLEMENTED
] = NULL
;
9395 ssh
->packet_dispatch
[SSH2_MSG_SERVICE_REQUEST
] = NULL
;
9396 ssh
->packet_dispatch
[SSH2_MSG_SERVICE_ACCEPT
] = NULL
;
9397 ssh
->packet_dispatch
[SSH2_MSG_KEXINIT
] = NULL
;
9398 ssh
->packet_dispatch
[SSH2_MSG_NEWKEYS
] = NULL
;
9399 ssh
->packet_dispatch
[SSH2_MSG_KEXDH_INIT
] = NULL
;
9400 ssh
->packet_dispatch
[SSH2_MSG_KEXDH_REPLY
] = NULL
;
9401 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = NULL; duplicate case value */
9402 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = NULL; duplicate case value */
9403 ssh
->packet_dispatch
[SSH2_MSG_KEX_DH_GEX_INIT
] = NULL
;
9404 ssh
->packet_dispatch
[SSH2_MSG_KEX_DH_GEX_REPLY
] = NULL
;
9405 ssh
->packet_dispatch
[SSH2_MSG_USERAUTH_REQUEST
] = NULL
;
9406 ssh
->packet_dispatch
[SSH2_MSG_USERAUTH_FAILURE
] = NULL
;
9407 ssh
->packet_dispatch
[SSH2_MSG_USERAUTH_SUCCESS
] = NULL
;
9408 ssh
->packet_dispatch
[SSH2_MSG_USERAUTH_BANNER
] = NULL
;
9409 ssh
->packet_dispatch
[SSH2_MSG_USERAUTH_PK_OK
] = NULL
;
9410 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = NULL; duplicate case value */
9411 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = NULL; duplicate case value */
9412 ssh
->packet_dispatch
[SSH2_MSG_USERAUTH_INFO_RESPONSE
] = NULL
;
9413 ssh
->packet_dispatch
[SSH2_MSG_GLOBAL_REQUEST
] = NULL
;
9414 ssh
->packet_dispatch
[SSH2_MSG_REQUEST_SUCCESS
] = NULL
;
9415 ssh
->packet_dispatch
[SSH2_MSG_REQUEST_FAILURE
] = NULL
;
9416 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_OPEN
] = NULL
;
9417 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
] = NULL
;
9418 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_OPEN_FAILURE
] = NULL
;
9419 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_WINDOW_ADJUST
] = NULL
;
9420 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_DATA
] = NULL
;
9421 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_EXTENDED_DATA
] = NULL
;
9422 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_EOF
] = NULL
;
9423 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_CLOSE
] = NULL
;
9424 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_REQUEST
] = NULL
;
9425 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_SUCCESS
] = NULL
;
9426 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_FAILURE
] = NULL
;
9429 * These special message types we install handlers for.
9431 ssh
->packet_dispatch
[SSH2_MSG_DISCONNECT
] = ssh2_msg_disconnect
;
9432 ssh
->packet_dispatch
[SSH2_MSG_IGNORE
] = ssh_msg_ignore
; /* shared with SSH-1 */
9433 ssh
->packet_dispatch
[SSH2_MSG_DEBUG
] = ssh2_msg_debug
;
9436 static void ssh2_timer(void *ctx
, long now
)
9440 if (ssh
->state
== SSH_STATE_CLOSED
)
9443 if (!ssh
->kex_in_progress
&& conf_get_int(ssh
->conf
, CONF_ssh_rekey_time
) != 0 &&
9444 now
- ssh
->next_rekey
>= 0) {
9445 do_ssh2_transport(ssh
, "timeout", -1, NULL
);
9449 static void ssh2_protocol(Ssh ssh
, void *vin
, int inlen
,
9450 struct Packet
*pktin
)
9452 unsigned char *in
= (unsigned char *)vin
;
9453 if (ssh
->state
== SSH_STATE_CLOSED
)
9457 ssh
->incoming_data_size
+= pktin
->encrypted_len
;
9458 if (!ssh
->kex_in_progress
&&
9459 ssh
->max_data_size
!= 0 &&
9460 ssh
->incoming_data_size
> ssh
->max_data_size
)
9461 do_ssh2_transport(ssh
, "too much data received", -1, NULL
);
9464 if (pktin
&& ssh
->packet_dispatch
[pktin
->type
]) {
9465 ssh
->packet_dispatch
[pktin
->type
](ssh
, pktin
);
9469 if (!ssh
->protocol_initial_phase_done
||
9470 (pktin
&& pktin
->type
>= 20 && pktin
->type
< 50)) {
9471 if (do_ssh2_transport(ssh
, in
, inlen
, pktin
) &&
9472 !ssh
->protocol_initial_phase_done
) {
9473 ssh
->protocol_initial_phase_done
= TRUE
;
9475 * Allow authconn to initialise itself.
9477 do_ssh2_authconn(ssh
, NULL
, 0, NULL
);
9480 do_ssh2_authconn(ssh
, in
, inlen
, pktin
);
9484 static void ssh_cache_conf_values(Ssh ssh
)
9486 ssh
->logomitdata
= conf_get_int(ssh
->conf
, CONF_logomitdata
);
9490 * Called to set up the connection.
9492 * Returns an error message, or NULL on success.
9494 static const char *ssh_init(void *frontend_handle
, void **backend_handle
,
9495 Conf
*conf
, char *host
, int port
, char **realhost
,
9496 int nodelay
, int keepalive
)
9501 ssh
= snew(struct ssh_tag
);
9502 ssh
->conf
= conf_copy(conf
);
9503 ssh_cache_conf_values(ssh
);
9504 ssh
->version
= 0; /* when not ready yet */
9507 ssh
->v1_cipher_ctx
= NULL
;
9508 ssh
->crcda_ctx
= NULL
;
9509 ssh
->cscipher
= NULL
;
9510 ssh
->cs_cipher_ctx
= NULL
;
9511 ssh
->sccipher
= NULL
;
9512 ssh
->sc_cipher_ctx
= NULL
;
9514 ssh
->cs_mac_ctx
= NULL
;
9516 ssh
->sc_mac_ctx
= NULL
;
9518 ssh
->cs_comp_ctx
= NULL
;
9520 ssh
->sc_comp_ctx
= NULL
;
9522 ssh
->kex_ctx
= NULL
;
9523 ssh
->hostkey
= NULL
;
9525 ssh
->close_expected
= FALSE
;
9526 ssh
->clean_exit
= FALSE
;
9527 ssh
->state
= SSH_STATE_PREPACKET
;
9528 ssh
->size_needed
= FALSE
;
9529 ssh
->eof_needed
= FALSE
;
9532 ssh
->deferred_send_data
= NULL
;
9533 ssh
->deferred_len
= 0;
9534 ssh
->deferred_size
= 0;
9535 ssh
->fallback_cmd
= 0;
9536 ssh
->pkt_kctx
= SSH2_PKTCTX_NOKEX
;
9537 ssh
->pkt_actx
= SSH2_PKTCTX_NOAUTH
;
9538 ssh
->x11disp
= NULL
;
9539 ssh
->v1_compressing
= FALSE
;
9540 ssh
->v2_outgoing_sequence
= 0;
9541 ssh
->ssh1_rdpkt_crstate
= 0;
9542 ssh
->ssh2_rdpkt_crstate
= 0;
9543 ssh
->do_ssh_init_crstate
= 0;
9544 ssh
->ssh_gotdata_crstate
= 0;
9545 ssh
->do_ssh1_connection_crstate
= 0;
9546 ssh
->do_ssh1_login_crstate
= 0;
9547 ssh
->do_ssh2_transport_crstate
= 0;
9548 ssh
->do_ssh2_authconn_crstate
= 0;
9549 ssh
->do_ssh_init_state
= NULL
;
9550 ssh
->do_ssh1_login_state
= NULL
;
9551 ssh
->do_ssh2_transport_state
= NULL
;
9552 ssh
->do_ssh2_authconn_state
= NULL
;
9555 ssh
->mainchan
= NULL
;
9556 ssh
->throttled_all
= 0;
9557 ssh
->v1_stdout_throttling
= 0;
9559 ssh
->queuelen
= ssh
->queuesize
= 0;
9560 ssh
->queueing
= FALSE
;
9561 ssh
->qhead
= ssh
->qtail
= NULL
;
9562 ssh
->deferred_rekey_reason
= NULL
;
9563 bufchain_init(&ssh
->queued_incoming_data
);
9564 ssh
->frozen
= FALSE
;
9565 ssh
->username
= NULL
;
9566 ssh
->sent_console_eof
= FALSE
;
9567 ssh
->got_pty
= FALSE
;
9569 *backend_handle
= ssh
;
9572 if (crypto_startup() == 0)
9573 return "Microsoft high encryption pack not installed!";
9576 ssh
->frontend
= frontend_handle
;
9577 ssh
->term_width
= conf_get_int(ssh
->conf
, CONF_width
);
9578 ssh
->term_height
= conf_get_int(ssh
->conf
, CONF_height
);
9580 ssh
->channels
= NULL
;
9581 ssh
->rportfwds
= NULL
;
9582 ssh
->portfwds
= NULL
;
9587 ssh
->conn_throttle_count
= 0;
9588 ssh
->overall_bufsize
= 0;
9589 ssh
->fallback_cmd
= 0;
9591 ssh
->protocol
= NULL
;
9593 ssh
->protocol_initial_phase_done
= FALSE
;
9597 ssh
->incoming_data_size
= ssh
->outgoing_data_size
=
9598 ssh
->deferred_data_size
= 0L;
9599 ssh
->max_data_size
= parse_blocksize(conf_get_str(ssh
->conf
,
9600 CONF_ssh_rekey_data
));
9601 ssh
->kex_in_progress
= FALSE
;
9604 ssh
->gsslibs
= NULL
;
9607 p
= connect_to_host(ssh
, host
, port
, realhost
, nodelay
, keepalive
);
9616 static void ssh_free(void *handle
)
9618 Ssh ssh
= (Ssh
) handle
;
9619 struct ssh_channel
*c
;
9620 struct ssh_rportfwd
*pf
;
9622 if (ssh
->v1_cipher_ctx
)
9623 ssh
->cipher
->free_context(ssh
->v1_cipher_ctx
);
9624 if (ssh
->cs_cipher_ctx
)
9625 ssh
->cscipher
->free_context(ssh
->cs_cipher_ctx
);
9626 if (ssh
->sc_cipher_ctx
)
9627 ssh
->sccipher
->free_context(ssh
->sc_cipher_ctx
);
9628 if (ssh
->cs_mac_ctx
)
9629 ssh
->csmac
->free_context(ssh
->cs_mac_ctx
);
9630 if (ssh
->sc_mac_ctx
)
9631 ssh
->scmac
->free_context(ssh
->sc_mac_ctx
);
9632 if (ssh
->cs_comp_ctx
) {
9634 ssh
->cscomp
->compress_cleanup(ssh
->cs_comp_ctx
);
9636 zlib_compress_cleanup(ssh
->cs_comp_ctx
);
9638 if (ssh
->sc_comp_ctx
) {
9640 ssh
->sccomp
->decompress_cleanup(ssh
->sc_comp_ctx
);
9642 zlib_decompress_cleanup(ssh
->sc_comp_ctx
);
9645 dh_cleanup(ssh
->kex_ctx
);
9646 sfree(ssh
->savedhost
);
9648 while (ssh
->queuelen
-- > 0)
9649 ssh_free_packet(ssh
->queue
[ssh
->queuelen
]);
9652 while (ssh
->qhead
) {
9653 struct queued_handler
*qh
= ssh
->qhead
;
9654 ssh
->qhead
= qh
->next
;
9657 ssh
->qhead
= ssh
->qtail
= NULL
;
9659 if (ssh
->channels
) {
9660 while ((c
= delpos234(ssh
->channels
, 0)) != NULL
) {
9663 if (c
->u
.x11
.s
!= NULL
)
9664 x11_close(c
->u
.x11
.s
);
9667 case CHAN_SOCKDATA_DORMANT
:
9668 if (c
->u
.pfd
.s
!= NULL
)
9669 pfd_close(c
->u
.pfd
.s
);
9674 freetree234(ssh
->channels
);
9675 ssh
->channels
= NULL
;
9678 if (ssh
->rportfwds
) {
9679 while ((pf
= delpos234(ssh
->rportfwds
, 0)) != NULL
)
9681 freetree234(ssh
->rportfwds
);
9682 ssh
->rportfwds
= NULL
;
9684 sfree(ssh
->deferred_send_data
);
9686 x11_free_display(ssh
->x11disp
);
9687 sfree(ssh
->do_ssh_init_state
);
9688 sfree(ssh
->do_ssh1_login_state
);
9689 sfree(ssh
->do_ssh2_transport_state
);
9690 sfree(ssh
->do_ssh2_authconn_state
);
9693 sfree(ssh
->fullhostname
);
9694 if (ssh
->crcda_ctx
) {
9695 crcda_free_context(ssh
->crcda_ctx
);
9696 ssh
->crcda_ctx
= NULL
;
9699 ssh_do_close(ssh
, TRUE
);
9700 expire_timer_context(ssh
);
9702 pinger_free(ssh
->pinger
);
9703 bufchain_clear(&ssh
->queued_incoming_data
);
9704 sfree(ssh
->username
);
9705 conf_free(ssh
->conf
);
9708 ssh_gss_cleanup(ssh
->gsslibs
);
9716 * Reconfigure the SSH backend.
9718 static void ssh_reconfig(void *handle
, Conf
*conf
)
9720 Ssh ssh
= (Ssh
) handle
;
9721 char *rekeying
= NULL
, rekey_mandatory
= FALSE
;
9722 unsigned long old_max_data_size
;
9725 pinger_reconfig(ssh
->pinger
, ssh
->conf
, conf
);
9727 ssh_setup_portfwd(ssh
, conf
);
9729 rekey_time
= conf_get_int(conf
, CONF_ssh_rekey_time
);
9730 if (conf_get_int(ssh
->conf
, CONF_ssh_rekey_time
) != rekey_time
&&
9732 long new_next
= ssh
->last_rekey
+ rekey_time
*60*TICKSPERSEC
;
9733 long now
= GETTICKCOUNT();
9735 if (new_next
- now
< 0) {
9736 rekeying
= "timeout shortened";
9738 ssh
->next_rekey
= schedule_timer(new_next
- now
, ssh2_timer
, ssh
);
9742 old_max_data_size
= ssh
->max_data_size
;
9743 ssh
->max_data_size
= parse_blocksize(conf_get_str(ssh
->conf
,
9744 CONF_ssh_rekey_data
));
9745 if (old_max_data_size
!= ssh
->max_data_size
&&
9746 ssh
->max_data_size
!= 0) {
9747 if (ssh
->outgoing_data_size
> ssh
->max_data_size
||
9748 ssh
->incoming_data_size
> ssh
->max_data_size
)
9749 rekeying
= "data limit lowered";
9752 if (conf_get_int(ssh
->conf
, CONF_compression
) !=
9753 conf_get_int(conf
, CONF_compression
)) {
9754 rekeying
= "compression setting changed";
9755 rekey_mandatory
= TRUE
;
9758 for (i
= 0; i
< CIPHER_MAX
; i
++)
9759 if (conf_get_int_int(ssh
->conf
, CONF_ssh_cipherlist
, i
) !=
9760 conf_get_int_int(conf
, CONF_ssh_cipherlist
, i
)) {
9761 rekeying
= "cipher settings changed";
9762 rekey_mandatory
= TRUE
;
9764 if (conf_get_int(ssh
->conf
, CONF_ssh2_des_cbc
) !=
9765 conf_get_int(conf
, CONF_ssh2_des_cbc
)) {
9766 rekeying
= "cipher settings changed";
9767 rekey_mandatory
= TRUE
;
9770 conf_free(ssh
->conf
);
9771 ssh
->conf
= conf_copy(conf
);
9772 ssh_cache_conf_values(ssh
);
9775 if (!ssh
->kex_in_progress
) {
9776 do_ssh2_transport(ssh
, rekeying
, -1, NULL
);
9777 } else if (rekey_mandatory
) {
9778 ssh
->deferred_rekey_reason
= rekeying
;
9784 * Called to send data down the SSH connection.
9786 static int ssh_send(void *handle
, char *buf
, int len
)
9788 Ssh ssh
= (Ssh
) handle
;
9790 if (ssh
== NULL
|| ssh
->s
== NULL
|| ssh
->protocol
== NULL
)
9793 ssh
->protocol(ssh
, (unsigned char *)buf
, len
, 0);
9795 return ssh_sendbuffer(ssh
);
9799 * Called to query the current amount of buffered stdin data.
9801 static int ssh_sendbuffer(void *handle
)
9803 Ssh ssh
= (Ssh
) handle
;
9806 if (ssh
== NULL
|| ssh
->s
== NULL
|| ssh
->protocol
== NULL
)
9810 * If the SSH socket itself has backed up, add the total backup
9811 * size on that to any individual buffer on the stdin channel.
9814 if (ssh
->throttled_all
)
9815 override_value
= ssh
->overall_bufsize
;
9817 if (ssh
->version
== 1) {
9818 return override_value
;
9819 } else if (ssh
->version
== 2) {
9821 return override_value
;
9823 return (override_value
+
9824 bufchain_size(&ssh
->mainchan
->v
.v2
.outbuffer
));
9831 * Called to set the size of the window from SSH's POV.
9833 static void ssh_size(void *handle
, int width
, int height
)
9835 Ssh ssh
= (Ssh
) handle
;
9836 struct Packet
*pktout
;
9838 ssh
->term_width
= width
;
9839 ssh
->term_height
= height
;
9841 switch (ssh
->state
) {
9842 case SSH_STATE_BEFORE_SIZE
:
9843 case SSH_STATE_PREPACKET
:
9844 case SSH_STATE_CLOSED
:
9845 break; /* do nothing */
9846 case SSH_STATE_INTERMED
:
9847 ssh
->size_needed
= TRUE
; /* buffer for later */
9849 case SSH_STATE_SESSION
:
9850 if (!conf_get_int(ssh
->conf
, CONF_nopty
)) {
9851 if (ssh
->version
== 1) {
9852 send_packet(ssh
, SSH1_CMSG_WINDOW_SIZE
,
9853 PKT_INT
, ssh
->term_height
,
9854 PKT_INT
, ssh
->term_width
,
9855 PKT_INT
, 0, PKT_INT
, 0, PKT_END
);
9856 } else if (ssh
->mainchan
) {
9857 pktout
= ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
9858 ssh2_pkt_adduint32(pktout
, ssh
->mainchan
->remoteid
);
9859 ssh2_pkt_addstring(pktout
, "window-change");
9860 ssh2_pkt_addbool(pktout
, 0);
9861 ssh2_pkt_adduint32(pktout
, ssh
->term_width
);
9862 ssh2_pkt_adduint32(pktout
, ssh
->term_height
);
9863 ssh2_pkt_adduint32(pktout
, 0);
9864 ssh2_pkt_adduint32(pktout
, 0);
9865 ssh2_pkt_send(ssh
, pktout
);
9873 * Return a list of the special codes that make sense in this
9876 static const struct telnet_special
*ssh_get_specials(void *handle
)
9878 static const struct telnet_special ssh1_ignore_special
[] = {
9879 {"IGNORE message", TS_NOP
}
9881 static const struct telnet_special ssh2_ignore_special
[] = {
9882 {"IGNORE message", TS_NOP
},
9884 static const struct telnet_special ssh2_rekey_special
[] = {
9885 {"Repeat key exchange", TS_REKEY
},
9887 static const struct telnet_special ssh2_session_specials
[] = {
9890 /* These are the signal names defined by RFC 4254.
9891 * They include all the ISO C signals, but are a subset of the POSIX
9892 * required signals. */
9893 {"SIGINT (Interrupt)", TS_SIGINT
},
9894 {"SIGTERM (Terminate)", TS_SIGTERM
},
9895 {"SIGKILL (Kill)", TS_SIGKILL
},
9896 {"SIGQUIT (Quit)", TS_SIGQUIT
},
9897 {"SIGHUP (Hangup)", TS_SIGHUP
},
9898 {"More signals", TS_SUBMENU
},
9899 {"SIGABRT", TS_SIGABRT
}, {"SIGALRM", TS_SIGALRM
},
9900 {"SIGFPE", TS_SIGFPE
}, {"SIGILL", TS_SIGILL
},
9901 {"SIGPIPE", TS_SIGPIPE
}, {"SIGSEGV", TS_SIGSEGV
},
9902 {"SIGUSR1", TS_SIGUSR1
}, {"SIGUSR2", TS_SIGUSR2
},
9905 static const struct telnet_special specials_end
[] = {
9908 /* XXX review this length for any changes: */
9909 static struct telnet_special ssh_specials
[lenof(ssh2_ignore_special
) +
9910 lenof(ssh2_rekey_special
) +
9911 lenof(ssh2_session_specials
) +
9912 lenof(specials_end
)];
9913 Ssh ssh
= (Ssh
) handle
;
9915 #define ADD_SPECIALS(name) \
9917 assert((i + lenof(name)) <= lenof(ssh_specials)); \
9918 memcpy(&ssh_specials[i], name, sizeof name); \
9922 if (ssh
->version
== 1) {
9923 /* Don't bother offering IGNORE if we've decided the remote
9924 * won't cope with it, since we wouldn't bother sending it if
9926 if (!(ssh
->remote_bugs
& BUG_CHOKES_ON_SSH1_IGNORE
))
9927 ADD_SPECIALS(ssh1_ignore_special
);
9928 } else if (ssh
->version
== 2) {
9929 if (!(ssh
->remote_bugs
& BUG_CHOKES_ON_SSH2_IGNORE
))
9930 ADD_SPECIALS(ssh2_ignore_special
);
9931 if (!(ssh
->remote_bugs
& BUG_SSH2_REKEY
))
9932 ADD_SPECIALS(ssh2_rekey_special
);
9934 ADD_SPECIALS(ssh2_session_specials
);
9935 } /* else we're not ready yet */
9938 ADD_SPECIALS(specials_end
);
9939 return ssh_specials
;
9947 * Send special codes. TS_EOF is useful for `plink', so you
9948 * can send an EOF and collect resulting output (e.g. `plink
9951 static void ssh_special(void *handle
, Telnet_Special code
)
9953 Ssh ssh
= (Ssh
) handle
;
9954 struct Packet
*pktout
;
9956 if (code
== TS_EOF
) {
9957 if (ssh
->state
!= SSH_STATE_SESSION
) {
9959 * Buffer the EOF in case we are pre-SESSION, so we can
9960 * send it as soon as we reach SESSION.
9963 ssh
->eof_needed
= TRUE
;
9966 if (ssh
->version
== 1) {
9967 send_packet(ssh
, SSH1_CMSG_EOF
, PKT_END
);
9968 } else if (ssh
->mainchan
) {
9969 sshfwd_write_eof(ssh
->mainchan
);
9970 ssh
->send_ok
= 0; /* now stop trying to read from stdin */
9972 logevent("Sent EOF message");
9973 } else if (code
== TS_PING
|| code
== TS_NOP
) {
9974 if (ssh
->state
== SSH_STATE_CLOSED
9975 || ssh
->state
== SSH_STATE_PREPACKET
) return;
9976 if (ssh
->version
== 1) {
9977 if (!(ssh
->remote_bugs
& BUG_CHOKES_ON_SSH1_IGNORE
))
9978 send_packet(ssh
, SSH1_MSG_IGNORE
, PKT_STR
, "", PKT_END
);
9980 if (!(ssh
->remote_bugs
& BUG_CHOKES_ON_SSH2_IGNORE
)) {
9981 pktout
= ssh2_pkt_init(SSH2_MSG_IGNORE
);
9982 ssh2_pkt_addstring_start(pktout
);
9983 ssh2_pkt_send_noqueue(ssh
, pktout
);
9986 } else if (code
== TS_REKEY
) {
9987 if (!ssh
->kex_in_progress
&& ssh
->version
== 2) {
9988 do_ssh2_transport(ssh
, "at user request", -1, NULL
);
9990 } else if (code
== TS_BRK
) {
9991 if (ssh
->state
== SSH_STATE_CLOSED
9992 || ssh
->state
== SSH_STATE_PREPACKET
) return;
9993 if (ssh
->version
== 1) {
9994 logevent("Unable to send BREAK signal in SSH-1");
9995 } else if (ssh
->mainchan
) {
9996 pktout
= ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
9997 ssh2_pkt_adduint32(pktout
, ssh
->mainchan
->remoteid
);
9998 ssh2_pkt_addstring(pktout
, "break");
9999 ssh2_pkt_addbool(pktout
, 0);
10000 ssh2_pkt_adduint32(pktout
, 0); /* default break length */
10001 ssh2_pkt_send(ssh
, pktout
);
10004 /* Is is a POSIX signal? */
10005 char *signame
= NULL
;
10006 if (code
== TS_SIGABRT
) signame
= "ABRT";
10007 if (code
== TS_SIGALRM
) signame
= "ALRM";
10008 if (code
== TS_SIGFPE
) signame
= "FPE";
10009 if (code
== TS_SIGHUP
) signame
= "HUP";
10010 if (code
== TS_SIGILL
) signame
= "ILL";
10011 if (code
== TS_SIGINT
) signame
= "INT";
10012 if (code
== TS_SIGKILL
) signame
= "KILL";
10013 if (code
== TS_SIGPIPE
) signame
= "PIPE";
10014 if (code
== TS_SIGQUIT
) signame
= "QUIT";
10015 if (code
== TS_SIGSEGV
) signame
= "SEGV";
10016 if (code
== TS_SIGTERM
) signame
= "TERM";
10017 if (code
== TS_SIGUSR1
) signame
= "USR1";
10018 if (code
== TS_SIGUSR2
) signame
= "USR2";
10019 /* The SSH-2 protocol does in principle support arbitrary named
10020 * signals, including signame@domain, but we don't support those. */
10022 /* It's a signal. */
10023 if (ssh
->version
== 2 && ssh
->mainchan
) {
10024 pktout
= ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
10025 ssh2_pkt_adduint32(pktout
, ssh
->mainchan
->remoteid
);
10026 ssh2_pkt_addstring(pktout
, "signal");
10027 ssh2_pkt_addbool(pktout
, 0);
10028 ssh2_pkt_addstring(pktout
, signame
);
10029 ssh2_pkt_send(ssh
, pktout
);
10030 logeventf(ssh
, "Sent signal SIG%s", signame
);
10033 /* Never heard of it. Do nothing */
10038 void *new_sock_channel(void *handle
, Socket s
)
10040 Ssh ssh
= (Ssh
) handle
;
10041 struct ssh_channel
*c
;
10042 c
= snew(struct ssh_channel
);
10045 ssh2_channel_init(c
);
10046 c
->halfopen
= TRUE
;
10047 c
->type
= CHAN_SOCKDATA_DORMANT
;/* identify channel type */
10049 add234(ssh
->channels
, c
);
10054 * This is called when stdout/stderr (the entity to which
10055 * from_backend sends data) manages to clear some backlog.
10057 static void ssh_unthrottle(void *handle
, int bufsize
)
10059 Ssh ssh
= (Ssh
) handle
;
10062 if (ssh
->version
== 1) {
10063 if (ssh
->v1_stdout_throttling
&& bufsize
< SSH1_BUFFER_LIMIT
) {
10064 ssh
->v1_stdout_throttling
= 0;
10065 ssh_throttle_conn(ssh
, -1);
10068 if (ssh
->mainchan
) {
10069 ssh2_set_window(ssh
->mainchan
,
10070 bufsize
< ssh
->mainchan
->v
.v2
.locmaxwin ?
10071 ssh
->mainchan
->v
.v2
.locmaxwin
- bufsize
: 0);
10072 if (conf_get_int(ssh
->conf
, CONF_ssh_simple
))
10075 buflimit
= ssh
->mainchan
->v
.v2
.locmaxwin
;
10076 if (ssh
->mainchan
->throttling_conn
&& bufsize
<= buflimit
) {
10077 ssh
->mainchan
->throttling_conn
= 0;
10078 ssh_throttle_conn(ssh
, -1);
10084 * Now process any SSH connection data that was stashed in our
10085 * queue while we were frozen.
10087 ssh_process_queued_incoming_data(ssh
);
10090 void ssh_send_port_open(void *channel
, char *hostname
, int port
, char *org
)
10092 struct ssh_channel
*c
= (struct ssh_channel
*)channel
;
10094 struct Packet
*pktout
;
10096 logeventf(ssh
, "Opening forwarded connection to %s:%d", hostname
, port
);
10098 if (ssh
->version
== 1) {
10099 send_packet(ssh
, SSH1_MSG_PORT_OPEN
,
10100 PKT_INT
, c
->localid
,
10103 /* PKT_STR, <org:orgport>, */
10106 pktout
= ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN
);
10107 ssh2_pkt_addstring(pktout
, "direct-tcpip");
10108 ssh2_pkt_adduint32(pktout
, c
->localid
);
10109 ssh2_pkt_adduint32(pktout
, c
->v
.v2
.locwindow
);/* our window size */
10110 ssh2_pkt_adduint32(pktout
, OUR_V2_MAXPKT
); /* our max pkt size */
10111 ssh2_pkt_addstring(pktout
, hostname
);
10112 ssh2_pkt_adduint32(pktout
, port
);
10114 * We make up values for the originator data; partly it's
10115 * too much hassle to keep track, and partly I'm not
10116 * convinced the server should be told details like that
10117 * about my local network configuration.
10118 * The "originator IP address" is syntactically a numeric
10119 * IP address, and some servers (e.g., Tectia) get upset
10120 * if it doesn't match this syntax.
10122 ssh2_pkt_addstring(pktout
, "0.0.0.0");
10123 ssh2_pkt_adduint32(pktout
, 0);
10124 ssh2_pkt_send(ssh
, pktout
);
10128 static int ssh_connected(void *handle
)
10130 Ssh ssh
= (Ssh
) handle
;
10131 return ssh
->s
!= NULL
;
10134 static int ssh_sendok(void *handle
)
10136 Ssh ssh
= (Ssh
) handle
;
10137 return ssh
->send_ok
;
10140 static int ssh_ldisc(void *handle
, int option
)
10142 Ssh ssh
= (Ssh
) handle
;
10143 if (option
== LD_ECHO
)
10144 return ssh
->echoing
;
10145 if (option
== LD_EDIT
)
10146 return ssh
->editing
;
10150 static void ssh_provide_ldisc(void *handle
, void *ldisc
)
10152 Ssh ssh
= (Ssh
) handle
;
10153 ssh
->ldisc
= ldisc
;
10156 static void ssh_provide_logctx(void *handle
, void *logctx
)
10158 Ssh ssh
= (Ssh
) handle
;
10159 ssh
->logctx
= logctx
;
10162 static int ssh_return_exitcode(void *handle
)
10164 Ssh ssh
= (Ssh
) handle
;
10165 if (ssh
->s
!= NULL
)
10168 return (ssh
->exitcode
>= 0 ? ssh
->exitcode
: INT_MAX
);
10172 * cfg_info for SSH is the currently running version of the
10173 * protocol. (1 for 1; 2 for 2; 0 for not-decided-yet.)
10175 static int ssh_cfg_info(void *handle
)
10177 Ssh ssh
= (Ssh
) handle
;
10178 return ssh
->version
;
10182 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
10183 * that fails. This variable is the means by which scp.c can reach
10184 * into the SSH code and find out which one it got.
10186 extern int ssh_fallback_cmd(void *handle
)
10188 Ssh ssh
= (Ssh
) handle
;
10189 return ssh
->fallback_cmd
;
10192 Backend ssh_backend
= {
10202 ssh_return_exitcode
,
10206 ssh_provide_logctx
,