17 #define SSH1_MSG_DISCONNECT 1 /* 0x1 */
18 #define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */
19 #define SSH1_CMSG_SESSION_KEY 3 /* 0x3 */
20 #define SSH1_CMSG_USER 4 /* 0x4 */
21 #define SSH1_CMSG_AUTH_RSA 6 /* 0x6 */
22 #define SSH1_SMSG_AUTH_RSA_CHALLENGE 7 /* 0x7 */
23 #define SSH1_CMSG_AUTH_RSA_RESPONSE 8 /* 0x8 */
24 #define SSH1_CMSG_AUTH_PASSWORD 9 /* 0x9 */
25 #define SSH1_CMSG_REQUEST_PTY 10 /* 0xa */
26 #define SSH1_CMSG_WINDOW_SIZE 11 /* 0xb */
27 #define SSH1_CMSG_EXEC_SHELL 12 /* 0xc */
28 #define SSH1_CMSG_EXEC_CMD 13 /* 0xd */
29 #define SSH1_SMSG_SUCCESS 14 /* 0xe */
30 #define SSH1_SMSG_FAILURE 15 /* 0xf */
31 #define SSH1_CMSG_STDIN_DATA 16 /* 0x10 */
32 #define SSH1_SMSG_STDOUT_DATA 17 /* 0x11 */
33 #define SSH1_SMSG_STDERR_DATA 18 /* 0x12 */
34 #define SSH1_CMSG_EOF 19 /* 0x13 */
35 #define SSH1_SMSG_EXIT_STATUS 20 /* 0x14 */
36 #define SSH1_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* 0x15 */
37 #define SSH1_MSG_CHANNEL_OPEN_FAILURE 22 /* 0x16 */
38 #define SSH1_MSG_CHANNEL_DATA 23 /* 0x17 */
39 #define SSH1_MSG_CHANNEL_CLOSE 24 /* 0x18 */
40 #define SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* 0x19 */
41 #define SSH1_SMSG_X11_OPEN 27 /* 0x1b */
42 #define SSH1_CMSG_PORT_FORWARD_REQUEST 28 /* 0x1c */
43 #define SSH1_MSG_PORT_OPEN 29 /* 0x1d */
44 #define SSH1_CMSG_AGENT_REQUEST_FORWARDING 30 /* 0x1e */
45 #define SSH1_SMSG_AGENT_OPEN 31 /* 0x1f */
46 #define SSH1_MSG_IGNORE 32 /* 0x20 */
47 #define SSH1_CMSG_EXIT_CONFIRMATION 33 /* 0x21 */
48 #define SSH1_CMSG_X11_REQUEST_FORWARDING 34 /* 0x22 */
49 #define SSH1_CMSG_AUTH_RHOSTS_RSA 35 /* 0x23 */
50 #define SSH1_MSG_DEBUG 36 /* 0x24 */
51 #define SSH1_CMSG_REQUEST_COMPRESSION 37 /* 0x25 */
52 #define SSH1_CMSG_AUTH_TIS 39 /* 0x27 */
53 #define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 /* 0x28 */
54 #define SSH1_CMSG_AUTH_TIS_RESPONSE 41 /* 0x29 */
55 #define SSH1_CMSG_AUTH_CCARD 70 /* 0x46 */
56 #define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71 /* 0x47 */
57 #define SSH1_CMSG_AUTH_CCARD_RESPONSE 72 /* 0x48 */
59 #define SSH1_AUTH_TIS 5 /* 0x5 */
60 #define SSH1_AUTH_CCARD 16 /* 0x10 */
62 #define SSH1_PROTOFLAG_SCREEN_NUMBER 1 /* 0x1 */
63 /* Mask for protoflags we will echo back to server if seen */
64 #define SSH1_PROTOFLAGS_SUPPORTED 0 /* 0x1 */
66 #define SSH2_MSG_DISCONNECT 1 /* 0x1 */
67 #define SSH2_MSG_IGNORE 2 /* 0x2 */
68 #define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */
69 #define SSH2_MSG_DEBUG 4 /* 0x4 */
70 #define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */
71 #define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */
72 #define SSH2_MSG_KEXINIT 20 /* 0x14 */
73 #define SSH2_MSG_NEWKEYS 21 /* 0x15 */
74 #define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */
75 #define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */
76 #define SSH2_MSG_KEX_DH_GEX_REQUEST 30 /* 0x1e */
77 #define SSH2_MSG_KEX_DH_GEX_GROUP 31 /* 0x1f */
78 #define SSH2_MSG_KEX_DH_GEX_INIT 32 /* 0x20 */
79 #define SSH2_MSG_KEX_DH_GEX_REPLY 33 /* 0x21 */
80 #define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */
81 #define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */
82 #define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */
83 #define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */
84 #define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */
85 #define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */
86 #define SSH2_MSG_USERAUTH_INFO_REQUEST 60 /* 0x3c */
87 #define SSH2_MSG_USERAUTH_INFO_RESPONSE 61 /* 0x3d */
88 #define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */
89 #define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */
90 #define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */
91 #define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */
92 #define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */
93 #define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */
94 #define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */
95 #define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */
96 #define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */
97 #define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */
98 #define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */
99 #define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */
100 #define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */
101 #define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */
104 * Packet type contexts, so that ssh2_pkt_type can correctly decode
105 * the ambiguous type numbers back into the correct type strings.
107 #define SSH2_PKTCTX_DHGROUP 0x0001
108 #define SSH2_PKTCTX_DHGEX 0x0002
109 #define SSH2_PKTCTX_KEX_MASK 0x000F
110 #define SSH2_PKTCTX_PUBLICKEY 0x0010
111 #define SSH2_PKTCTX_PASSWORD 0x0020
112 #define SSH2_PKTCTX_KBDINTER 0x0040
113 #define SSH2_PKTCTX_AUTH_MASK 0x00F0
115 #define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */
116 #define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */
117 #define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */
118 #define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */
119 #define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */
120 #define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */
121 #define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */
122 #define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */
123 #define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */
124 #define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */
125 #define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */
126 #define SSH2_DISCONNECT_TOO_MANY_CONNECTIONS 12 /* 0xc */
127 #define SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER 13 /* 0xd */
128 #define SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE 14 /* 0xe */
129 #define SSH2_DISCONNECT_ILLEGAL_USER_NAME 15 /* 0xf */
131 static const char *const ssh2_disconnect_reasons[] = {
133 "SSH_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT",
134 "SSH_DISCONNECT_PROTOCOL_ERROR",
135 "SSH_DISCONNECT_KEY_EXCHANGE_FAILED",
136 "SSH_DISCONNECT_HOST_AUTHENTICATION_FAILED",
137 "SSH_DISCONNECT_MAC_ERROR",
138 "SSH_DISCONNECT_COMPRESSION_ERROR",
139 "SSH_DISCONNECT_SERVICE_NOT_AVAILABLE",
140 "SSH_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED",
141 "SSH_DISCONNECT_HOST_KEY_NOT_VERIFIABLE",
142 "SSH_DISCONNECT_CONNECTION_LOST",
143 "SSH_DISCONNECT_BY_APPLICATION",
144 "SSH_DISCONNECT_TOO_MANY_CONNECTIONS",
145 "SSH_DISCONNECT_AUTH_CANCELLED_BY_USER",
146 "SSH_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE",
147 "SSH_DISCONNECT_ILLEGAL_USER_NAME",
150 #define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */
151 #define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */
152 #define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */
153 #define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */
155 #define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
158 * Various remote-bug flags.
160 #define BUG_CHOKES_ON_SSH1_IGNORE 1
161 #define BUG_SSH2_HMAC 2
162 #define BUG_NEEDS_SSH1_PLAIN_PASSWORD 4
163 #define BUG_CHOKES_ON_RSA 8
164 #define BUG_SSH2_RSA_PADDING 16
165 #define BUG_SSH2_DERIVEKEY 32
166 #define BUG_SSH2_REKEY 64
167 #define BUG_SSH2_PK_SESSIONID 128
170 * Codes for terminal modes.
171 * Most of these are the same in SSH-1 and SSH-2.
172 * This list is derived from draft-ietf-secsh-connect-25 and
175 static const struct {
176 const char* const mode;
178 enum { TTY_OP_CHAR, TTY_OP_BOOL } type;
180 /* "V" prefix discarded for special characters relative to SSH specs */
181 { "INTR", 1, TTY_OP_CHAR },
182 { "QUIT", 2, TTY_OP_CHAR },
183 { "ERASE", 3, TTY_OP_CHAR },
184 { "KILL", 4, TTY_OP_CHAR },
185 { "EOF", 5, TTY_OP_CHAR },
186 { "EOL", 6, TTY_OP_CHAR },
187 { "EOL2", 7, TTY_OP_CHAR },
188 { "START", 8, TTY_OP_CHAR },
189 { "STOP", 9, TTY_OP_CHAR },
190 { "SUSP", 10, TTY_OP_CHAR },
191 { "DSUSP", 11, TTY_OP_CHAR },
192 { "REPRINT", 12, TTY_OP_CHAR },
193 { "WERASE", 13, TTY_OP_CHAR },
194 { "LNEXT", 14, TTY_OP_CHAR },
195 { "FLUSH", 15, TTY_OP_CHAR },
196 { "SWTCH", 16, TTY_OP_CHAR },
197 { "STATUS", 17, TTY_OP_CHAR },
198 { "DISCARD", 18, TTY_OP_CHAR },
199 { "IGNPAR", 30, TTY_OP_BOOL },
200 { "PARMRK", 31, TTY_OP_BOOL },
201 { "INPCK", 32, TTY_OP_BOOL },
202 { "ISTRIP", 33, TTY_OP_BOOL },
203 { "INLCR", 34, TTY_OP_BOOL },
204 { "IGNCR", 35, TTY_OP_BOOL },
205 { "ICRNL", 36, TTY_OP_BOOL },
206 { "IUCLC", 37, TTY_OP_BOOL },
207 { "IXON", 38, TTY_OP_BOOL },
208 { "IXANY", 39, TTY_OP_BOOL },
209 { "IXOFF", 40, TTY_OP_BOOL },
210 { "IMAXBEL", 41, TTY_OP_BOOL },
211 { "ISIG", 50, TTY_OP_BOOL },
212 { "ICANON", 51, TTY_OP_BOOL },
213 { "XCASE", 52, TTY_OP_BOOL },
214 { "ECHO", 53, TTY_OP_BOOL },
215 { "ECHOE", 54, TTY_OP_BOOL },
216 { "ECHOK", 55, TTY_OP_BOOL },
217 { "ECHONL", 56, TTY_OP_BOOL },
218 { "NOFLSH", 57, TTY_OP_BOOL },
219 { "TOSTOP", 58, TTY_OP_BOOL },
220 { "IEXTEN", 59, TTY_OP_BOOL },
221 { "ECHOCTL", 60, TTY_OP_BOOL },
222 { "ECHOKE", 61, TTY_OP_BOOL },
223 { "PENDIN", 62, TTY_OP_BOOL }, /* XXX is this a real mode? */
224 { "OPOST", 70, TTY_OP_BOOL },
225 { "OLCUC", 71, TTY_OP_BOOL },
226 { "ONLCR", 72, TTY_OP_BOOL },
227 { "OCRNL", 73, TTY_OP_BOOL },
228 { "ONOCR", 74, TTY_OP_BOOL },
229 { "ONLRET", 75, TTY_OP_BOOL },
230 { "CS7", 90, TTY_OP_BOOL },
231 { "CS8", 91, TTY_OP_BOOL },
232 { "PARENB", 92, TTY_OP_BOOL },
233 { "PARODD", 93, TTY_OP_BOOL }
236 /* Miscellaneous other tty-related constants. */
237 #define SSH_TTY_OP_END 0
238 /* The opcodes for ISPEED/OSPEED differ between SSH-1 and SSH-2. */
239 #define SSH1_TTY_OP_ISPEED 192
240 #define SSH1_TTY_OP_OSPEED 193
241 #define SSH2_TTY_OP_ISPEED 128
242 #define SSH2_TTY_OP_OSPEED 129
244 /* Helper functions for parsing tty-related config. */
245 static unsigned int ssh_tty_parse_specchar(char *s)
250 ret = ctrlparse(s, &next);
251 if (!next) ret = s[0];
253 ret = 255; /* special value meaning "don't set" */
257 static unsigned int ssh_tty_parse_boolean(char *s)
259 if (stricmp(s, "yes") == 0 ||
260 stricmp(s, "on") == 0 ||
261 stricmp(s, "true") == 0 ||
262 stricmp(s, "+") == 0)
264 else if (stricmp(s, "no") == 0 ||
265 stricmp(s, "off") == 0 ||
266 stricmp(s, "false") == 0 ||
267 stricmp(s, "-") == 0)
268 return 0; /* false */
270 return (atoi(s) != 0);
273 #define translate(x) if (type == x) return #x
274 #define translatec(x,ctx) if (type == x && (pkt_ctx & ctx)) return #x
275 static char *ssh1_pkt_type(int type)
277 translate(SSH1_MSG_DISCONNECT);
278 translate(SSH1_SMSG_PUBLIC_KEY);
279 translate(SSH1_CMSG_SESSION_KEY);
280 translate(SSH1_CMSG_USER);
281 translate(SSH1_CMSG_AUTH_RSA);
282 translate(SSH1_SMSG_AUTH_RSA_CHALLENGE);
283 translate(SSH1_CMSG_AUTH_RSA_RESPONSE);
284 translate(SSH1_CMSG_AUTH_PASSWORD);
285 translate(SSH1_CMSG_REQUEST_PTY);
286 translate(SSH1_CMSG_WINDOW_SIZE);
287 translate(SSH1_CMSG_EXEC_SHELL);
288 translate(SSH1_CMSG_EXEC_CMD);
289 translate(SSH1_SMSG_SUCCESS);
290 translate(SSH1_SMSG_FAILURE);
291 translate(SSH1_CMSG_STDIN_DATA);
292 translate(SSH1_SMSG_STDOUT_DATA);
293 translate(SSH1_SMSG_STDERR_DATA);
294 translate(SSH1_CMSG_EOF);
295 translate(SSH1_SMSG_EXIT_STATUS);
296 translate(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION);
297 translate(SSH1_MSG_CHANNEL_OPEN_FAILURE);
298 translate(SSH1_MSG_CHANNEL_DATA);
299 translate(SSH1_MSG_CHANNEL_CLOSE);
300 translate(SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION);
301 translate(SSH1_SMSG_X11_OPEN);
302 translate(SSH1_CMSG_PORT_FORWARD_REQUEST);
303 translate(SSH1_MSG_PORT_OPEN);
304 translate(SSH1_CMSG_AGENT_REQUEST_FORWARDING);
305 translate(SSH1_SMSG_AGENT_OPEN);
306 translate(SSH1_MSG_IGNORE);
307 translate(SSH1_CMSG_EXIT_CONFIRMATION);
308 translate(SSH1_CMSG_X11_REQUEST_FORWARDING);
309 translate(SSH1_CMSG_AUTH_RHOSTS_RSA);
310 translate(SSH1_MSG_DEBUG);
311 translate(SSH1_CMSG_REQUEST_COMPRESSION);
312 translate(SSH1_CMSG_AUTH_TIS);
313 translate(SSH1_SMSG_AUTH_TIS_CHALLENGE);
314 translate(SSH1_CMSG_AUTH_TIS_RESPONSE);
315 translate(SSH1_CMSG_AUTH_CCARD);
316 translate(SSH1_SMSG_AUTH_CCARD_CHALLENGE);
317 translate(SSH1_CMSG_AUTH_CCARD_RESPONSE);
320 static char *ssh2_pkt_type(int pkt_ctx, int type)
322 translate(SSH2_MSG_DISCONNECT);
323 translate(SSH2_MSG_IGNORE);
324 translate(SSH2_MSG_UNIMPLEMENTED);
325 translate(SSH2_MSG_DEBUG);
326 translate(SSH2_MSG_SERVICE_REQUEST);
327 translate(SSH2_MSG_SERVICE_ACCEPT);
328 translate(SSH2_MSG_KEXINIT);
329 translate(SSH2_MSG_NEWKEYS);
330 translatec(SSH2_MSG_KEXDH_INIT, SSH2_PKTCTX_DHGROUP);
331 translatec(SSH2_MSG_KEXDH_REPLY, SSH2_PKTCTX_DHGROUP);
332 translatec(SSH2_MSG_KEX_DH_GEX_REQUEST, SSH2_PKTCTX_DHGEX);
333 translatec(SSH2_MSG_KEX_DH_GEX_GROUP, SSH2_PKTCTX_DHGEX);
334 translatec(SSH2_MSG_KEX_DH_GEX_INIT, SSH2_PKTCTX_DHGEX);
335 translatec(SSH2_MSG_KEX_DH_GEX_REPLY, SSH2_PKTCTX_DHGEX);
336 translate(SSH2_MSG_USERAUTH_REQUEST);
337 translate(SSH2_MSG_USERAUTH_FAILURE);
338 translate(SSH2_MSG_USERAUTH_SUCCESS);
339 translate(SSH2_MSG_USERAUTH_BANNER);
340 translatec(SSH2_MSG_USERAUTH_PK_OK, SSH2_PKTCTX_PUBLICKEY);
341 translatec(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, SSH2_PKTCTX_PASSWORD);
342 translatec(SSH2_MSG_USERAUTH_INFO_REQUEST, SSH2_PKTCTX_KBDINTER);
343 translatec(SSH2_MSG_USERAUTH_INFO_RESPONSE, SSH2_PKTCTX_KBDINTER);
344 translate(SSH2_MSG_GLOBAL_REQUEST);
345 translate(SSH2_MSG_REQUEST_SUCCESS);
346 translate(SSH2_MSG_REQUEST_FAILURE);
347 translate(SSH2_MSG_CHANNEL_OPEN);
348 translate(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
349 translate(SSH2_MSG_CHANNEL_OPEN_FAILURE);
350 translate(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
351 translate(SSH2_MSG_CHANNEL_DATA);
352 translate(SSH2_MSG_CHANNEL_EXTENDED_DATA);
353 translate(SSH2_MSG_CHANNEL_EOF);
354 translate(SSH2_MSG_CHANNEL_CLOSE);
355 translate(SSH2_MSG_CHANNEL_REQUEST);
356 translate(SSH2_MSG_CHANNEL_SUCCESS);
357 translate(SSH2_MSG_CHANNEL_FAILURE);
363 /* Enumeration values for fields in SSH-1 packets */
365 PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM,
366 /* These values are for communicating relevant semantics of
367 * fields to the packet logging code. */
368 PKTT_OTHER, PKTT_PASSWORD, PKTT_DATA
372 * Coroutine mechanics for the sillier bits of the code. If these
373 * macros look impenetrable to you, you might find it helpful to
376 * http://www.chiark.greenend.org.uk/~sgtatham/coroutines.html
378 * which explains the theory behind these macros.
380 * In particular, if you are getting `case expression not constant'
381 * errors when building with MS Visual Studio, this is because MS's
382 * Edit and Continue debugging feature causes their compiler to
383 * violate ANSI C. To disable Edit and Continue debugging:
385 * - right-click ssh.c in the FileView
387 * - select the C/C++ tab and the General category
388 * - under `Debug info:', select anything _other_ than `Program
389 * Database for Edit and Continue'.
391 #define crBegin(v) { int *crLine = &v; switch(v) { case 0:;
394 if (!ssh->t) ssh->t = snew(struct t); \
396 #define crFinish(z) } *crLine = 0; return (z); }
397 #define crFinishV } *crLine = 0; return; }
398 #define crReturn(z) \
400 *crLine =__LINE__; return (z); case __LINE__:;\
404 *crLine=__LINE__; return; case __LINE__:;\
406 #define crStop(z) do{ *crLine = 0; return (z); }while(0)
407 #define crStopV do{ *crLine = 0; return; }while(0)
408 #define crWaitUntil(c) do { crReturn(0); } while (!(c))
409 #define crWaitUntilV(c) do { crReturnV; } while (!(c))
411 typedef struct ssh_tag *Ssh;
414 static struct Packet *ssh1_pkt_init(int pkt_type);
415 static struct Packet *ssh2_pkt_init(int pkt_type);
416 static void ssh_pkt_ensure(struct Packet *, int length);
417 static void ssh_pkt_adddata(struct Packet *, void *data, int len);
418 static void ssh_pkt_addbyte(struct Packet *, unsigned char value);
419 static void ssh2_pkt_addbool(struct Packet *, unsigned char value);
420 static void ssh_pkt_adduint32(struct Packet *, unsigned long value);
421 static void ssh_pkt_addstring_start(struct Packet *);
422 static void ssh_pkt_addstring_str(struct Packet *, char *data);
423 static void ssh_pkt_addstring_data(struct Packet *, char *data, int len);
424 static void ssh_pkt_addstring(struct Packet *, char *data);
425 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len);
426 static void ssh1_pkt_addmp(struct Packet *, Bignum b);
427 static void ssh2_pkt_addmp(struct Packet *, Bignum b);
428 static int ssh2_pkt_construct(Ssh, struct Packet *);
429 static void ssh2_pkt_send(Ssh, struct Packet *);
430 static void ssh2_pkt_send_noqueue(Ssh, struct Packet *);
431 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
432 struct Packet *pktin);
433 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
434 struct Packet *pktin);
437 * Buffer management constants. There are several of these for
438 * various different purposes:
440 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
441 * on a local data stream before we throttle the whole SSH
442 * connection (in SSH-1 only). Throttling the whole connection is
443 * pretty drastic so we set this high in the hope it won't
446 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
447 * on the SSH connection itself before we defensively throttle
448 * _all_ local data streams. This is pretty drastic too (though
449 * thankfully unlikely in SSH-2 since the window mechanism should
450 * ensure that the server never has any need to throttle its end
451 * of the connection), so we set this high as well.
453 * - OUR_V2_WINSIZE is the maximum window size we present on SSH-2
457 #define SSH1_BUFFER_LIMIT 32768
458 #define SSH_MAX_BACKLOG 32768
459 #define OUR_V2_WINSIZE 16384
460 #define OUR_V2_MAXPKT 0x4000UL
462 const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
464 const static struct ssh_mac *macs[] = {
467 const static struct ssh_mac *buggymacs[] = {
468 &ssh_sha1_buggy, &ssh_md5
471 static void *ssh_comp_none_init(void)
475 static void ssh_comp_none_cleanup(void *handle)
478 static int ssh_comp_none_block(void *handle, unsigned char *block, int len,
479 unsigned char **outblock, int *outlen)
483 static int ssh_comp_none_disable(void *handle)
487 const static struct ssh_compress ssh_comp_none = {
489 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
490 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
491 ssh_comp_none_disable, NULL
493 extern const struct ssh_compress ssh_zlib;
494 const static struct ssh_compress *compressions[] = {
495 &ssh_zlib, &ssh_comp_none
498 enum { /* channel types */
503 CHAN_SOCKDATA_DORMANT /* one the remote hasn't confirmed */
507 * 2-3-4 tree storing channels.
510 Ssh ssh; /* pointer back to main context */
511 unsigned remoteid, localid;
513 /* True if we opened this channel but server hasn't confirmed. */
516 * In SSH-1, this value contains four bits:
518 * 1 We have sent SSH1_MSG_CHANNEL_CLOSE.
519 * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
520 * 4 We have received SSH1_MSG_CHANNEL_CLOSE.
521 * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
523 * A channel is completely finished with when all four bits are set.
527 struct ssh1_data_channel {
530 struct ssh2_data_channel {
532 unsigned remwindow, remmaxpkt;
537 struct ssh_agent_channel {
538 unsigned char *message;
539 unsigned char msglen[4];
540 unsigned lensofar, totallen;
542 struct ssh_x11_channel {
545 struct ssh_pfd_channel {
552 * 2-3-4 tree storing remote->local port forwardings. SSH-1 and SSH-2
553 * use this structure in different ways, reflecting SSH-2's
554 * altogether saner approach to port forwarding.
556 * In SSH-1, you arrange a remote forwarding by sending the server
557 * the remote port number, and the local destination host:port.
558 * When a connection comes in, the server sends you back that
559 * host:port pair, and you connect to it. This is a ready-made
560 * security hole if you're not on the ball: a malicious server
561 * could send you back _any_ host:port pair, so if you trustingly
562 * connect to the address it gives you then you've just opened the
563 * entire inside of your corporate network just by connecting
564 * through it to a dodgy SSH server. Hence, we must store a list of
565 * host:port pairs we _are_ trying to forward to, and reject a
566 * connection request from the server if it's not in the list.
568 * In SSH-2, each side of the connection minds its own business and
569 * doesn't send unnecessary information to the other. You arrange a
570 * remote forwarding by sending the server just the remote port
571 * number. When a connection comes in, the server tells you which
572 * of its ports was connected to; and _you_ have to remember what
573 * local host:port pair went with that port number.
575 * Hence, in SSH-1 this structure is indexed by destination
576 * host:port pair, whereas in SSH-2 it is indexed by source port.
578 struct ssh_portfwd; /* forward declaration */
580 struct ssh_rportfwd {
581 unsigned sport, dport;
584 struct ssh_portfwd *pfrec;
586 #define free_rportfwd(pf) ( \
587 ((pf) ? (sfree((pf)->sportdesc)) : (void)0 ), sfree(pf) )
590 * Separately to the rportfwd tree (which is for looking up port
591 * open requests from the server), a tree of _these_ structures is
592 * used to keep track of all the currently open port forwardings,
593 * so that we can reconfigure in mid-session if the user requests
597 enum { DESTROY, KEEP, CREATE } status;
599 unsigned sport, dport;
602 struct ssh_rportfwd *remote;
606 #define free_portfwd(pf) ( \
607 ((pf) ? (sfree((pf)->saddr), sfree((pf)->daddr), \
608 sfree((pf)->sserv), sfree((pf)->dserv)) : (void)0 ), sfree(pf) )
611 long length; /* length of `data' actually used */
612 long forcepad; /* SSH-2: force padding to at least this length */
613 int type; /* only used for incoming packets */
614 unsigned long sequence; /* SSH-2 incoming sequence number */
615 unsigned char *data; /* allocated storage */
616 unsigned char *body; /* offset of payload within `data' */
617 long savedpos; /* temporary index into `data' (for strings) */
618 long maxlen; /* amount of storage allocated for `data' */
619 long encrypted_len; /* for SSH-2 total-size counting */
622 * State associated with packet logging
626 struct logblank_t *blanks;
629 static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
630 struct Packet *pktin);
631 static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
632 struct Packet *pktin);
633 static void ssh1_protocol_setup(Ssh ssh);
634 static void ssh2_protocol_setup(Ssh ssh);
635 static void ssh_size(void *handle, int width, int height);
636 static void ssh_special(void *handle, Telnet_Special);
637 static int ssh2_try_send(struct ssh_channel *c);
638 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len);
639 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize);
640 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin);
641 static int ssh_sendbuffer(void *handle);
642 static int ssh_do_close(Ssh ssh, int notify_exit);
643 static unsigned long ssh_pkt_getuint32(struct Packet *pkt);
644 static int ssh2_pkt_getbool(struct Packet *pkt);
645 static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length);
646 static void ssh2_timer(void *ctx, long now);
647 static int do_ssh2_transport(Ssh ssh, void *vin, int inlen,
648 struct Packet *pktin);
650 struct rdpkt1_state_tag {
651 long len, pad, biglen, to_read;
652 unsigned long realcrc, gotcrc;
656 struct Packet *pktin;
659 struct rdpkt2_state_tag {
660 long len, pad, payload, packetlen, maclen;
663 unsigned long incoming_sequence;
664 struct Packet *pktin;
667 typedef void (*handler_fn_t)(Ssh ssh, struct Packet *pktin);
668 typedef void (*chandler_fn_t)(Ssh ssh, struct Packet *pktin, void *ctx);
670 struct queued_handler;
671 struct queued_handler {
673 chandler_fn_t handler;
675 struct queued_handler *next;
679 const struct plug_function_table *fn;
680 /* the above field _must_ be first in the structure */
682 SHA_State exhash, exhashbase;
689 unsigned char session_key[32];
691 int v1_remote_protoflags;
692 int v1_local_protoflags;
693 int agentfwd_enabled;
696 const struct ssh_cipher *cipher;
699 const struct ssh2_cipher *cscipher, *sccipher;
700 void *cs_cipher_ctx, *sc_cipher_ctx;
701 const struct ssh_mac *csmac, *scmac;
702 void *cs_mac_ctx, *sc_mac_ctx;
703 const struct ssh_compress *cscomp, *sccomp;
704 void *cs_comp_ctx, *sc_comp_ctx;
705 const struct ssh_kex *kex;
706 const struct ssh_signkey *hostkey;
707 unsigned char v2_session_id[20];
713 int echoing, editing;
717 int ospeed, ispeed; /* temporaries */
718 int term_width, term_height;
720 tree234 *channels; /* indexed by local id */
721 struct ssh_channel *mainchan; /* primary session channel */
725 tree234 *rportfwds, *portfwds;
729 SSH_STATE_BEFORE_SIZE,
735 int size_needed, eof_needed;
737 struct Packet **queue;
738 int queuelen, queuesize;
740 unsigned char *deferred_send_data;
741 int deferred_len, deferred_size;
744 * Gross hack: pscp will try to start SFTP but fall back to
745 * scp1 if that fails. This variable is the means by which
746 * scp.c can reach into the SSH code and find out which one it
752 * Used for username and password input.
754 char *userpass_input_buffer;
755 int userpass_input_buflen;
756 int userpass_input_bufpos;
757 int userpass_input_echo;
764 int v1_throttle_count;
767 int v1_stdout_throttling;
768 unsigned long v2_outgoing_sequence;
770 int ssh1_rdpkt_crstate;
771 int ssh2_rdpkt_crstate;
772 int do_ssh_init_crstate;
773 int ssh_gotdata_crstate;
774 int do_ssh1_login_crstate;
775 int do_ssh1_connection_crstate;
776 int do_ssh2_transport_crstate;
777 int do_ssh2_authconn_crstate;
779 void *do_ssh_init_state;
780 void *do_ssh1_login_state;
781 void *do_ssh2_transport_state;
782 void *do_ssh2_authconn_state;
784 struct rdpkt1_state_tag rdpkt1_state;
785 struct rdpkt2_state_tag rdpkt2_state;
787 /* SSH-1 and SSH-2 use this for different things, but both use it */
788 int protocol_initial_phase_done;
790 void (*protocol) (Ssh ssh, void *vin, int inlen,
792 struct Packet *(*s_rdpkt) (Ssh ssh, unsigned char **data, int *datalen);
795 * We maintain a full _copy_ of a Config structure here, not
796 * merely a pointer to it. That way, when we're passed a new
797 * one for reconfiguration, we can check the differences and
798 * potentially reconfigure port forwardings etc in mid-session.
803 * Used to transfer data back from async callbacks.
805 void *agent_response;
806 int agent_response_len;
810 * The SSH connection can be set as `frozen', meaning we are
811 * not currently accepting incoming data from the network. This
812 * is slightly more serious than setting the _socket_ as
813 * frozen, because we may already have had data passed to us
814 * from the network which we need to delay processing until
815 * after the freeze is lifted, so we also need a bufchain to
819 bufchain queued_incoming_data;
822 * Dispatch table for packet types that we may have to deal
825 handler_fn_t packet_dispatch[256];
828 * Queues of one-off handler functions for success/failure
829 * indications from a request.
831 struct queued_handler *qhead, *qtail;
834 * This module deals with sending keepalives.
839 * Track incoming and outgoing data sizes and time, for
842 unsigned long incoming_data_size, outgoing_data_size, deferred_data_size;
843 unsigned long max_data_size;
845 long next_rekey, last_rekey;
846 char *deferred_rekey_reason; /* points to STATIC string; don't free */
849 #define logevent(s) logevent(ssh->frontend, s)
851 /* logevent, only printf-formatted. */
852 static void logeventf(Ssh ssh, const char *fmt, ...)
858 buf = dupvprintf(fmt, ap);
864 #define bombout(msg) \
866 char *text = dupprintf msg; \
867 ssh_do_close(ssh, FALSE); \
869 connection_fatal(ssh->frontend, "%s", text); \
873 /* Functions to leave bits out of the SSH packet log file. */
875 static void dont_log_password(Ssh ssh, struct Packet *pkt, int blanktype)
877 if (ssh->cfg.logomitpass)
878 pkt->logmode = blanktype;
881 static void dont_log_data(Ssh ssh, struct Packet *pkt, int blanktype)
883 if (ssh->cfg.logomitdata)
884 pkt->logmode = blanktype;
887 static void end_log_omission(Ssh ssh, struct Packet *pkt)
889 pkt->logmode = PKTLOG_EMIT;
892 /* Helper function for common bits of parsing cfg.ttymodes. */
893 static void parse_ttymodes(Ssh ssh, char *modes,
894 void (*do_mode)(void *data, char *mode, char *val),
898 char *t = strchr(modes, '\t');
899 char *m = snewn(t-modes+1, char);
901 strncpy(m, modes, t-modes);
904 val = get_ttymode(ssh->frontend, m);
908 do_mode(data, m, val);
911 modes += strlen(modes) + 1;
915 static int ssh_channelcmp(void *av, void *bv)
917 struct ssh_channel *a = (struct ssh_channel *) av;
918 struct ssh_channel *b = (struct ssh_channel *) bv;
919 if (a->localid < b->localid)
921 if (a->localid > b->localid)
925 static int ssh_channelfind(void *av, void *bv)
927 unsigned *a = (unsigned *) av;
928 struct ssh_channel *b = (struct ssh_channel *) bv;
936 static int ssh_rportcmp_ssh1(void *av, void *bv)
938 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
939 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
941 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
942 return i < 0 ? -1 : +1;
943 if (a->dport > b->dport)
945 if (a->dport < b->dport)
950 static int ssh_rportcmp_ssh2(void *av, void *bv)
952 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
953 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
955 if (a->sport > b->sport)
957 if (a->sport < b->sport)
963 * Special form of strcmp which can cope with NULL inputs. NULL is
964 * defined to sort before even the empty string.
966 static int nullstrcmp(const char *a, const char *b)
968 if (a == NULL && b == NULL)
977 static int ssh_portcmp(void *av, void *bv)
979 struct ssh_portfwd *a = (struct ssh_portfwd *) av;
980 struct ssh_portfwd *b = (struct ssh_portfwd *) bv;
982 if (a->type > b->type)
984 if (a->type < b->type)
986 if (a->addressfamily > b->addressfamily)
988 if (a->addressfamily < b->addressfamily)
990 if ( (i = nullstrcmp(a->saddr, b->saddr)) != 0)
991 return i < 0 ? -1 : +1;
992 if (a->sport > b->sport)
994 if (a->sport < b->sport)
996 if (a->type != 'D') {
997 if ( (i = nullstrcmp(a->daddr, b->daddr)) != 0)
998 return i < 0 ? -1 : +1;
999 if (a->dport > b->dport)
1001 if (a->dport < b->dport)
1007 static int alloc_channel_id(Ssh ssh)
1009 const unsigned CHANNEL_NUMBER_OFFSET = 256;
1010 unsigned low, high, mid;
1012 struct ssh_channel *c;
1015 * First-fit allocation of channel numbers: always pick the
1016 * lowest unused one. To do this, binary-search using the
1017 * counted B-tree to find the largest channel ID which is in a
1018 * contiguous sequence from the beginning. (Precisely
1019 * everything in that sequence must have ID equal to its tree
1020 * index plus CHANNEL_NUMBER_OFFSET.)
1022 tsize = count234(ssh->channels);
1026 while (high - low > 1) {
1027 mid = (high + low) / 2;
1028 c = index234(ssh->channels, mid);
1029 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
1030 low = mid; /* this one is fine */
1032 high = mid; /* this one is past it */
1035 * Now low points to either -1, or the tree index of the
1036 * largest ID in the initial sequence.
1039 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
1040 assert(NULL == find234(ssh->channels, &i, ssh_channelfind));
1042 return low + 1 + CHANNEL_NUMBER_OFFSET;
1045 static void c_write(Ssh ssh, const char *buf, int len)
1047 if ((flags & FLAG_STDERR)) {
1049 for (i = 0; i < len; i++)
1051 fputc(buf[i], stderr);
1054 from_backend(ssh->frontend, 1, buf, len);
1057 static void c_write_untrusted(Ssh ssh, const char *buf, int len)
1060 for (i = 0; i < len; i++) {
1062 c_write(ssh, "\r\n", 2);
1063 else if ((buf[i] & 0x60) || (buf[i] == '\r'))
1064 c_write(ssh, buf + i, 1);
1068 static void c_write_str(Ssh ssh, const char *buf)
1070 c_write(ssh, buf, strlen(buf));
1073 static void ssh_free_packet(struct Packet *pkt)
1078 static struct Packet *ssh_new_packet(void)
1080 struct Packet *pkt = snew(struct Packet);
1082 pkt->body = pkt->data = NULL;
1084 pkt->logmode = PKTLOG_EMIT;
1092 * Collect incoming data in the incoming packet buffer.
1093 * Decipher and verify the packet when it is completely read.
1094 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
1095 * Update the *data and *datalen variables.
1096 * Return a Packet structure when a packet is completed.
1098 static struct Packet *ssh1_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
1100 struct rdpkt1_state_tag *st = &ssh->rdpkt1_state;
1102 crBegin(ssh->ssh1_rdpkt_crstate);
1104 st->pktin = ssh_new_packet();
1106 st->pktin->type = 0;
1107 st->pktin->length = 0;
1109 for (st->i = st->len = 0; st->i < 4; st->i++) {
1110 while ((*datalen) == 0)
1112 st->len = (st->len << 8) + **data;
1113 (*data)++, (*datalen)--;
1116 st->pad = 8 - (st->len % 8);
1117 st->biglen = st->len + st->pad;
1118 st->pktin->length = st->len - 5;
1120 if (st->biglen < 0) {
1121 bombout(("Extremely large packet length from server suggests"
1122 " data stream corruption"));
1123 ssh_free_packet(st->pktin);
1127 st->pktin->maxlen = st->biglen;
1128 st->pktin->data = snewn(st->biglen + APIEXTRA, unsigned char);
1130 st->to_read = st->biglen;
1131 st->p = st->pktin->data;
1132 while (st->to_read > 0) {
1133 st->chunk = st->to_read;
1134 while ((*datalen) == 0)
1136 if (st->chunk > (*datalen))
1137 st->chunk = (*datalen);
1138 memcpy(st->p, *data, st->chunk);
1140 *datalen -= st->chunk;
1142 st->to_read -= st->chunk;
1145 if (ssh->cipher && detect_attack(ssh->crcda_ctx, st->pktin->data,
1146 st->biglen, NULL)) {
1147 bombout(("Network attack (CRC compensation) detected!"));
1148 ssh_free_packet(st->pktin);
1153 ssh->cipher->decrypt(ssh->v1_cipher_ctx, st->pktin->data, st->biglen);
1155 st->realcrc = crc32_compute(st->pktin->data, st->biglen - 4);
1156 st->gotcrc = GET_32BIT(st->pktin->data + st->biglen - 4);
1157 if (st->gotcrc != st->realcrc) {
1158 bombout(("Incorrect CRC received on packet"));
1159 ssh_free_packet(st->pktin);
1163 st->pktin->body = st->pktin->data + st->pad + 1;
1164 st->pktin->savedpos = 0;
1166 if (ssh->v1_compressing) {
1167 unsigned char *decompblk;
1169 if (!zlib_decompress_block(ssh->sc_comp_ctx,
1170 st->pktin->body - 1, st->pktin->length + 1,
1171 &decompblk, &decomplen)) {
1172 bombout(("Zlib decompression encountered invalid data"));
1173 ssh_free_packet(st->pktin);
1177 if (st->pktin->maxlen < st->pad + decomplen) {
1178 st->pktin->maxlen = st->pad + decomplen;
1179 st->pktin->data = sresize(st->pktin->data,
1180 st->pktin->maxlen + APIEXTRA,
1182 st->pktin->body = st->pktin->data + st->pad + 1;
1185 memcpy(st->pktin->body - 1, decompblk, decomplen);
1187 st->pktin->length = decomplen - 1;
1190 st->pktin->type = st->pktin->body[-1];
1193 * Log incoming packet, possibly omitting sensitive fields.
1197 struct logblank_t blank;
1198 if (ssh->cfg.logomitdata) {
1199 int do_blank = FALSE, blank_prefix = 0;
1200 /* "Session data" packets - omit the data field */
1201 if ((st->pktin->type == SSH1_SMSG_STDOUT_DATA) ||
1202 (st->pktin->type == SSH1_SMSG_STDERR_DATA)) {
1203 do_blank = TRUE; blank_prefix = 0;
1204 } else if (st->pktin->type == SSH1_MSG_CHANNEL_DATA) {
1205 do_blank = TRUE; blank_prefix = 4;
1208 blank.offset = blank_prefix;
1209 blank.len = st->pktin->length;
1210 blank.type = PKTLOG_OMIT;
1214 log_packet(ssh->logctx,
1215 PKT_INCOMING, st->pktin->type,
1216 ssh1_pkt_type(st->pktin->type),
1217 st->pktin->body, st->pktin->length,
1221 crFinish(st->pktin);
1224 static struct Packet *ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
1226 struct rdpkt2_state_tag *st = &ssh->rdpkt2_state;
1228 crBegin(ssh->ssh2_rdpkt_crstate);
1230 st->pktin = ssh_new_packet();
1232 st->pktin->type = 0;
1233 st->pktin->length = 0;
1235 st->cipherblk = ssh->sccipher->blksize;
1238 if (st->cipherblk < 8)
1241 st->pktin->data = snewn(st->cipherblk + APIEXTRA, unsigned char);
1244 * Acquire and decrypt the first block of the packet. This will
1245 * contain the length and padding details.
1247 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
1248 while ((*datalen) == 0)
1250 st->pktin->data[st->i] = *(*data)++;
1255 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1256 st->pktin->data, st->cipherblk);
1259 * Now get the length and padding figures.
1261 st->len = GET_32BIT(st->pktin->data);
1262 st->pad = st->pktin->data[4];
1265 * _Completely_ silly lengths should be stomped on before they
1266 * do us any more damage.
1268 if (st->len < 0 || st->pad < 0 || st->len + st->pad < 0) {
1269 bombout(("Incoming packet was garbled on decryption"));
1270 ssh_free_packet(st->pktin);
1275 * This enables us to deduce the payload length.
1277 st->payload = st->len - st->pad - 1;
1279 st->pktin->length = st->payload + 5;
1282 * So now we can work out the total packet length.
1284 st->packetlen = st->len + 4;
1285 st->maclen = ssh->scmac ? ssh->scmac->len : 0;
1288 * Allocate memory for the rest of the packet.
1290 st->pktin->maxlen = st->packetlen + st->maclen;
1291 st->pktin->data = sresize(st->pktin->data,
1292 st->pktin->maxlen + APIEXTRA,
1296 * Read and decrypt the remainder of the packet.
1298 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
1300 while ((*datalen) == 0)
1302 st->pktin->data[st->i] = *(*data)++;
1305 /* Decrypt everything _except_ the MAC. */
1307 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1308 st->pktin->data + st->cipherblk,
1309 st->packetlen - st->cipherblk);
1311 st->pktin->encrypted_len = st->packetlen;
1317 && !ssh->scmac->verify(ssh->sc_mac_ctx, st->pktin->data, st->len + 4,
1318 st->incoming_sequence)) {
1319 bombout(("Incorrect MAC received on packet"));
1320 ssh_free_packet(st->pktin);
1324 st->pktin->sequence = st->incoming_sequence++;
1327 * Decompress packet payload.
1330 unsigned char *newpayload;
1333 ssh->sccomp->decompress(ssh->sc_comp_ctx,
1334 st->pktin->data + 5, st->pktin->length - 5,
1335 &newpayload, &newlen)) {
1336 if (st->pktin->maxlen < newlen + 5) {
1337 st->pktin->maxlen = newlen + 5;
1338 st->pktin->data = sresize(st->pktin->data,
1339 st->pktin->maxlen + APIEXTRA,
1342 st->pktin->length = 5 + newlen;
1343 memcpy(st->pktin->data + 5, newpayload, newlen);
1348 st->pktin->savedpos = 6;
1349 st->pktin->body = st->pktin->data;
1350 st->pktin->type = st->pktin->data[5];
1353 * Log incoming packet, possibly omitting sensitive fields.
1357 struct logblank_t blank;
1358 if (ssh->cfg.logomitdata) {
1359 int do_blank = FALSE, blank_prefix = 0;
1360 /* "Session data" packets - omit the data field */
1361 if (st->pktin->type == SSH2_MSG_CHANNEL_DATA) {
1362 do_blank = TRUE; blank_prefix = 4;
1363 } else if (st->pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
1364 do_blank = TRUE; blank_prefix = 8;
1367 blank.offset = blank_prefix;
1368 blank.len = (st->pktin->length-6) - blank_prefix;
1369 blank.type = PKTLOG_OMIT;
1373 log_packet(ssh->logctx, PKT_INCOMING, st->pktin->type,
1374 ssh2_pkt_type(ssh->pkt_ctx, st->pktin->type),
1375 st->pktin->data+6, st->pktin->length-6,
1379 crFinish(st->pktin);
1382 static int s_wrpkt_prepare(Ssh ssh, struct Packet *pkt, int *offset_p)
1384 int pad, biglen, i, pktoffs;
1388 * XXX various versions of SC (including 8.8.4) screw up the
1389 * register allocation in this function and use the same register
1390 * (D6) for len and as a temporary, with predictable results. The
1391 * following sledgehammer prevents this.
1398 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[12],
1399 ssh1_pkt_type(pkt->data[12]),
1400 pkt->body, pkt->length - (pkt->body - pkt->data),
1401 pkt->nblanks, pkt->blanks);
1402 sfree(pkt->blanks); pkt->blanks = NULL;
1405 if (ssh->v1_compressing) {
1406 unsigned char *compblk;
1408 zlib_compress_block(ssh->cs_comp_ctx,
1409 pkt->data + 12, pkt->length - 12,
1410 &compblk, &complen);
1411 memcpy(pkt->data + 12, compblk, complen);
1413 pkt->length = complen + 12;
1416 ssh_pkt_ensure(pkt, pkt->length + 4); /* space for CRC */
1418 len = pkt->length - 4 - 8; /* len(type+data+CRC) */
1419 pad = 8 - (len % 8);
1421 biglen = len + pad; /* len(padding+type+data+CRC) */
1423 for (i = pktoffs; i < 4+8; i++)
1424 pkt->data[i] = random_byte();
1425 crc = crc32_compute(pkt->data + pktoffs + 4, biglen - 4); /* all ex len */
1426 PUT_32BIT(pkt->data + pktoffs + 4 + biglen - 4, crc);
1427 PUT_32BIT(pkt->data + pktoffs, len);
1430 ssh->cipher->encrypt(ssh->v1_cipher_ctx,
1431 pkt->data + pktoffs + 4, biglen);
1433 if (offset_p) *offset_p = pktoffs;
1434 return biglen + 4; /* len(length+padding+type+data+CRC) */
1437 static void s_wrpkt(Ssh ssh, struct Packet *pkt)
1439 int len, backlog, offset;
1440 len = s_wrpkt_prepare(ssh, pkt, &offset);
1441 backlog = sk_write(ssh->s, (char *)pkt->data + offset, len);
1442 if (backlog > SSH_MAX_BACKLOG)
1443 ssh_throttle_all(ssh, 1, backlog);
1444 ssh_free_packet(pkt);
1447 static void s_wrpkt_defer(Ssh ssh, struct Packet *pkt)
1450 len = s_wrpkt_prepare(ssh, pkt, &offset);
1451 if (ssh->deferred_len + len > ssh->deferred_size) {
1452 ssh->deferred_size = ssh->deferred_len + len + 128;
1453 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1457 memcpy(ssh->deferred_send_data + ssh->deferred_len,
1458 pkt->data + offset, len);
1459 ssh->deferred_len += len;
1460 ssh_free_packet(pkt);
1464 * Construct a SSH-1 packet with the specified contents.
1465 * (This all-at-once interface used to be the only one, but now SSH-1
1466 * packets can also be constructed incrementally.)
1468 static struct Packet *construct_packet(Ssh ssh, int pkttype, va_list ap)
1474 pkt = ssh1_pkt_init(pkttype);
1476 while ((argtype = va_arg(ap, int)) != PKT_END) {
1477 unsigned char *argp, argchar;
1478 unsigned long argint;
1481 /* Actual fields in the packet */
1483 argint = va_arg(ap, int);
1484 ssh_pkt_adduint32(pkt, argint);
1487 argchar = (unsigned char) va_arg(ap, int);
1488 ssh_pkt_addbyte(pkt, argchar);
1491 argp = va_arg(ap, unsigned char *);
1492 arglen = va_arg(ap, int);
1493 ssh_pkt_adddata(pkt, argp, arglen);
1496 argp = va_arg(ap, unsigned char *);
1497 ssh_pkt_addstring(pkt, argp);
1500 bn = va_arg(ap, Bignum);
1501 ssh1_pkt_addmp(pkt, bn);
1503 /* Tokens for modifications to packet logging */
1505 dont_log_password(ssh, pkt, PKTLOG_BLANK);
1508 dont_log_data(ssh, pkt, PKTLOG_OMIT);
1511 end_log_omission(ssh, pkt);
1519 static void send_packet(Ssh ssh, int pkttype, ...)
1523 va_start(ap, pkttype);
1524 pkt = construct_packet(ssh, pkttype, ap);
1529 static void defer_packet(Ssh ssh, int pkttype, ...)
1533 va_start(ap, pkttype);
1534 pkt = construct_packet(ssh, pkttype, ap);
1536 s_wrpkt_defer(ssh, pkt);
1539 static int ssh_versioncmp(char *a, char *b)
1542 unsigned long av, bv;
1544 av = strtoul(a, &ae, 10);
1545 bv = strtoul(b, &be, 10);
1547 return (av < bv ? -1 : +1);
1552 av = strtoul(ae, &ae, 10);
1553 bv = strtoul(be, &be, 10);
1555 return (av < bv ? -1 : +1);
1560 * Utility routines for putting an SSH-protocol `string' and
1561 * `uint32' into a SHA state.
1563 static void sha_string(SHA_State * s, void *str, int len)
1565 unsigned char lenblk[4];
1566 PUT_32BIT(lenblk, len);
1567 SHA_Bytes(s, lenblk, 4);
1568 SHA_Bytes(s, str, len);
1571 static void sha_uint32(SHA_State * s, unsigned i)
1573 unsigned char intblk[4];
1574 PUT_32BIT(intblk, i);
1575 SHA_Bytes(s, intblk, 4);
1579 * Packet construction functions. Mostly shared between SSH-1 and SSH-2.
1581 static void ssh_pkt_ensure(struct Packet *pkt, int length)
1583 if (pkt->maxlen < length) {
1584 unsigned char *body = pkt->body;
1585 int offset = body ? pkt->data - body : 0;
1586 pkt->maxlen = length + 256;
1587 pkt->data = sresize(pkt->data, pkt->maxlen + APIEXTRA, unsigned char);
1588 if (body) pkt->body = pkt->data + offset;
1591 static void ssh_pkt_adddata(struct Packet *pkt, void *data, int len)
1593 if (pkt->logmode != PKTLOG_EMIT) {
1595 pkt->blanks = sresize(pkt->blanks, pkt->nblanks, struct logblank_t);
1597 pkt->blanks[pkt->nblanks-1].offset = pkt->length -
1598 (pkt->body - pkt->data);
1599 pkt->blanks[pkt->nblanks-1].len = len;
1600 pkt->blanks[pkt->nblanks-1].type = pkt->logmode;
1603 ssh_pkt_ensure(pkt, pkt->length);
1604 memcpy(pkt->data + pkt->length - len, data, len);
1606 static void ssh_pkt_addbyte(struct Packet *pkt, unsigned char byte)
1608 ssh_pkt_adddata(pkt, &byte, 1);
1610 static void ssh2_pkt_addbool(struct Packet *pkt, unsigned char value)
1612 ssh_pkt_adddata(pkt, &value, 1);
1614 static void ssh_pkt_adduint32(struct Packet *pkt, unsigned long value)
1617 PUT_32BIT(x, value);
1618 ssh_pkt_adddata(pkt, x, 4);
1620 static void ssh_pkt_addstring_start(struct Packet *pkt)
1622 ssh_pkt_adduint32(pkt, 0);
1623 pkt->savedpos = pkt->length;
1625 static void ssh_pkt_addstring_str(struct Packet *pkt, char *data)
1627 ssh_pkt_adddata(pkt, data, strlen(data));
1628 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
1630 static void ssh_pkt_addstring_data(struct Packet *pkt, char *data, int len)
1632 ssh_pkt_adddata(pkt, data, len);
1633 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
1635 static void ssh_pkt_addstring(struct Packet *pkt, char *data)
1637 ssh_pkt_addstring_start(pkt);
1638 ssh_pkt_addstring_str(pkt, data);
1640 static void ssh1_pkt_addmp(struct Packet *pkt, Bignum b)
1642 int len = ssh1_bignum_length(b);
1643 unsigned char *data = snewn(len, char);
1644 (void) ssh1_write_bignum(data, b);
1645 ssh_pkt_adddata(pkt, data, len);
1648 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len)
1651 int i, n = (bignum_bitcount(b) + 7) / 8;
1652 p = snewn(n + 1, unsigned char);
1654 fatalbox("out of memory");
1656 for (i = 1; i <= n; i++)
1657 p[i] = bignum_byte(b, n - i);
1659 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1661 memmove(p, p + i, n + 1 - i);
1665 static void ssh2_pkt_addmp(struct Packet *pkt, Bignum b)
1669 p = ssh2_mpint_fmt(b, &len);
1670 ssh_pkt_addstring_start(pkt);
1671 ssh_pkt_addstring_data(pkt, (char *)p, len);
1675 static struct Packet *ssh1_pkt_init(int pkt_type)
1677 struct Packet *pkt = ssh_new_packet();
1678 pkt->length = 4 + 8; /* space for length + max padding */
1679 ssh_pkt_addbyte(pkt, pkt_type);
1680 pkt->body = pkt->data + pkt->length;
1684 /* For legacy code (SSH-1 and -2 packet construction used to be separate) */
1685 #define ssh2_pkt_ensure(pkt, length) ssh_pkt_ensure(pkt, length)
1686 #define ssh2_pkt_adddata(pkt, data, len) ssh_pkt_adddata(pkt, data, len)
1687 #define ssh2_pkt_addbyte(pkt, byte) ssh_pkt_addbyte(pkt, byte)
1688 #define ssh2_pkt_adduint32(pkt, value) ssh_pkt_adduint32(pkt, value)
1689 #define ssh2_pkt_addstring_start(pkt) ssh_pkt_addstring_start(pkt)
1690 #define ssh2_pkt_addstring_str(pkt, data) ssh_pkt_addstring_str(pkt, data)
1691 #define ssh2_pkt_addstring_data(pkt, data, len) ssh_pkt_addstring_data(pkt, data, len)
1692 #define ssh2_pkt_addstring(pkt, data) ssh_pkt_addstring(pkt, data)
1694 static struct Packet *ssh2_pkt_init(int pkt_type)
1696 struct Packet *pkt = ssh_new_packet();
1699 ssh_pkt_addbyte(pkt, (unsigned char) pkt_type);
1700 pkt->body = pkt->data + pkt->length;
1705 * Construct an SSH-2 final-form packet: compress it, encrypt it,
1706 * put the MAC on it. Final packet, ready to be sent, is stored in
1707 * pkt->data. Total length is returned.
1709 static int ssh2_pkt_construct(Ssh ssh, struct Packet *pkt)
1711 int cipherblk, maclen, padding, i;
1714 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[5],
1715 ssh2_pkt_type(ssh->pkt_ctx, pkt->data[5]),
1716 pkt->body, pkt->length - (pkt->body - pkt->data),
1717 pkt->nblanks, pkt->blanks);
1718 sfree(pkt->blanks); pkt->blanks = NULL;
1722 * Compress packet payload.
1725 unsigned char *newpayload;
1728 ssh->cscomp->compress(ssh->cs_comp_ctx, pkt->data + 5,
1730 &newpayload, &newlen)) {
1732 ssh2_pkt_adddata(pkt, newpayload, newlen);
1738 * Add padding. At least four bytes, and must also bring total
1739 * length (minus MAC) up to a multiple of the block size.
1740 * If pkt->forcepad is set, make sure the packet is at least that size
1743 cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
1744 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
1746 if (pkt->length + padding < pkt->forcepad)
1747 padding = pkt->forcepad - pkt->length;
1749 (cipherblk - (pkt->length + padding) % cipherblk) % cipherblk;
1750 assert(padding <= 255);
1751 maclen = ssh->csmac ? ssh->csmac->len : 0;
1752 ssh2_pkt_ensure(pkt, pkt->length + padding + maclen);
1753 pkt->data[4] = padding;
1754 for (i = 0; i < padding; i++)
1755 pkt->data[pkt->length + i] = random_byte();
1756 PUT_32BIT(pkt->data, pkt->length + padding - 4);
1758 ssh->csmac->generate(ssh->cs_mac_ctx, pkt->data,
1759 pkt->length + padding,
1760 ssh->v2_outgoing_sequence);
1761 ssh->v2_outgoing_sequence++; /* whether or not we MACed */
1764 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
1765 pkt->data, pkt->length + padding);
1767 pkt->encrypted_len = pkt->length + padding;
1769 /* Ready-to-send packet starts at pkt->data. We return length. */
1770 return pkt->length + padding + maclen;
1774 * Routines called from the main SSH code to send packets. There
1775 * are quite a few of these, because we have two separate
1776 * mechanisms for delaying the sending of packets:
1778 * - In order to send an IGNORE message and a password message in
1779 * a single fixed-length blob, we require the ability to
1780 * concatenate the encrypted forms of those two packets _into_ a
1781 * single blob and then pass it to our <network.h> transport
1782 * layer in one go. Hence, there's a deferment mechanism which
1783 * works after packet encryption.
1785 * - In order to avoid sending any connection-layer messages
1786 * during repeat key exchange, we have to queue up any such
1787 * outgoing messages _before_ they are encrypted (and in
1788 * particular before they're allocated sequence numbers), and
1789 * then send them once we've finished.
1791 * I call these mechanisms `defer' and `queue' respectively, so as
1792 * to distinguish them reasonably easily.
1794 * The functions send_noqueue() and defer_noqueue() free the packet
1795 * structure they are passed. Every outgoing packet goes through
1796 * precisely one of these functions in its life; packets passed to
1797 * ssh2_pkt_send() or ssh2_pkt_defer() either go straight to one of
1798 * these or get queued, and then when the queue is later emptied
1799 * the packets are all passed to defer_noqueue().
1803 * Send an SSH-2 packet immediately, without queuing or deferring.
1805 static void ssh2_pkt_send_noqueue(Ssh ssh, struct Packet *pkt)
1809 len = ssh2_pkt_construct(ssh, pkt);
1810 backlog = sk_write(ssh->s, (char *)pkt->data, len);
1811 if (backlog > SSH_MAX_BACKLOG)
1812 ssh_throttle_all(ssh, 1, backlog);
1814 ssh->outgoing_data_size += pkt->encrypted_len;
1815 if (!ssh->kex_in_progress &&
1816 ssh->max_data_size != 0 &&
1817 ssh->outgoing_data_size > ssh->max_data_size)
1818 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
1820 ssh_free_packet(pkt);
1824 * Defer an SSH-2 packet.
1826 static void ssh2_pkt_defer_noqueue(Ssh ssh, struct Packet *pkt)
1828 int len = ssh2_pkt_construct(ssh, pkt);
1829 if (ssh->deferred_len + len > ssh->deferred_size) {
1830 ssh->deferred_size = ssh->deferred_len + len + 128;
1831 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1835 memcpy(ssh->deferred_send_data + ssh->deferred_len, pkt->data, len);
1836 ssh->deferred_len += len;
1837 ssh->deferred_data_size += pkt->encrypted_len;
1838 ssh_free_packet(pkt);
1842 * Queue an SSH-2 packet.
1844 static void ssh2_pkt_queue(Ssh ssh, struct Packet *pkt)
1846 assert(ssh->queueing);
1848 if (ssh->queuelen >= ssh->queuesize) {
1849 ssh->queuesize = ssh->queuelen + 32;
1850 ssh->queue = sresize(ssh->queue, ssh->queuesize, struct Packet *);
1853 ssh->queue[ssh->queuelen++] = pkt;
1857 * Either queue or send a packet, depending on whether queueing is
1860 static void ssh2_pkt_send(Ssh ssh, struct Packet *pkt)
1863 ssh2_pkt_queue(ssh, pkt);
1865 ssh2_pkt_send_noqueue(ssh, pkt);
1870 * Either queue or defer a packet, depending on whether queueing is
1873 static void ssh2_pkt_defer(Ssh ssh, struct Packet *pkt)
1876 ssh2_pkt_queue(ssh, pkt);
1878 ssh2_pkt_defer_noqueue(ssh, pkt);
1883 * Send the whole deferred data block constructed by
1884 * ssh2_pkt_defer() or SSH-1's defer_packet().
1886 * The expected use of the defer mechanism is that you call
1887 * ssh2_pkt_defer() a few times, then call ssh_pkt_defersend(). If
1888 * not currently queueing, this simply sets up deferred_send_data
1889 * and then sends it. If we _are_ currently queueing, the calls to
1890 * ssh2_pkt_defer() put the deferred packets on to the queue
1891 * instead, and therefore ssh_pkt_defersend() has no deferred data
1892 * to send. Hence, there's no need to make it conditional on
1895 static void ssh_pkt_defersend(Ssh ssh)
1898 backlog = sk_write(ssh->s, (char *)ssh->deferred_send_data,
1900 ssh->deferred_len = ssh->deferred_size = 0;
1901 sfree(ssh->deferred_send_data);
1902 ssh->deferred_send_data = NULL;
1903 if (backlog > SSH_MAX_BACKLOG)
1904 ssh_throttle_all(ssh, 1, backlog);
1906 ssh->outgoing_data_size += ssh->deferred_data_size;
1907 if (!ssh->kex_in_progress &&
1908 ssh->max_data_size != 0 &&
1909 ssh->outgoing_data_size > ssh->max_data_size)
1910 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
1911 ssh->deferred_data_size = 0;
1915 * Send all queued SSH-2 packets. We send them by means of
1916 * ssh2_pkt_defer_noqueue(), in case they included a pair of
1917 * packets that needed to be lumped together.
1919 static void ssh2_pkt_queuesend(Ssh ssh)
1923 assert(!ssh->queueing);
1925 for (i = 0; i < ssh->queuelen; i++)
1926 ssh2_pkt_defer_noqueue(ssh, ssh->queue[i]);
1929 ssh_pkt_defersend(ssh);
1933 void bndebug(char *string, Bignum b)
1937 p = ssh2_mpint_fmt(b, &len);
1938 debug(("%s", string));
1939 for (i = 0; i < len; i++)
1940 debug((" %02x", p[i]));
1946 static void sha_mpint(SHA_State * s, Bignum b)
1950 p = ssh2_mpint_fmt(b, &len);
1951 sha_string(s, p, len);
1956 * Packet decode functions for both SSH-1 and SSH-2.
1958 static unsigned long ssh_pkt_getuint32(struct Packet *pkt)
1960 unsigned long value;
1961 if (pkt->length - pkt->savedpos < 4)
1962 return 0; /* arrgh, no way to decline (FIXME?) */
1963 value = GET_32BIT(pkt->body + pkt->savedpos);
1967 static int ssh2_pkt_getbool(struct Packet *pkt)
1969 unsigned long value;
1970 if (pkt->length - pkt->savedpos < 1)
1971 return 0; /* arrgh, no way to decline (FIXME?) */
1972 value = pkt->body[pkt->savedpos] != 0;
1976 static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length)
1981 if (pkt->length - pkt->savedpos < 4)
1983 len = GET_32BIT(pkt->body + pkt->savedpos);
1988 if (pkt->length - pkt->savedpos < *length)
1990 *p = (char *)(pkt->body + pkt->savedpos);
1991 pkt->savedpos += *length;
1993 static void *ssh_pkt_getdata(struct Packet *pkt, int length)
1995 if (pkt->length - pkt->savedpos < length)
1997 pkt->savedpos += length;
1998 return pkt->body + (pkt->savedpos - length);
2000 static int ssh1_pkt_getrsakey(struct Packet *pkt, struct RSAKey *key,
2001 unsigned char **keystr)
2005 j = makekey(pkt->body + pkt->savedpos,
2006 pkt->length - pkt->savedpos,
2013 assert(pkt->savedpos < pkt->length);
2017 static Bignum ssh1_pkt_getmp(struct Packet *pkt)
2022 j = ssh1_read_bignum(pkt->body + pkt->savedpos,
2023 pkt->length - pkt->savedpos, &b);
2031 static Bignum ssh2_pkt_getmp(struct Packet *pkt)
2037 ssh_pkt_getstring(pkt, &p, &length);
2042 b = bignum_from_bytes((unsigned char *)p, length);
2047 * Helper function to add an SSH-2 signature blob to a packet.
2048 * Expects to be shown the public key blob as well as the signature
2049 * blob. Normally works just like ssh2_pkt_addstring, but will
2050 * fiddle with the signature packet if necessary for
2051 * BUG_SSH2_RSA_PADDING.
2053 static void ssh2_add_sigblob(Ssh ssh, struct Packet *pkt,
2054 void *pkblob_v, int pkblob_len,
2055 void *sigblob_v, int sigblob_len)
2057 unsigned char *pkblob = (unsigned char *)pkblob_v;
2058 unsigned char *sigblob = (unsigned char *)sigblob_v;
2060 /* dmemdump(pkblob, pkblob_len); */
2061 /* dmemdump(sigblob, sigblob_len); */
2064 * See if this is in fact an ssh-rsa signature and a buggy
2065 * server; otherwise we can just do this the easy way.
2067 if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) &&
2068 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
2069 int pos, len, siglen;
2072 * Find the byte length of the modulus.
2075 pos = 4+7; /* skip over "ssh-rsa" */
2076 pos += 4 + GET_32BIT(pkblob+pos); /* skip over exponent */
2077 len = GET_32BIT(pkblob+pos); /* find length of modulus */
2078 pos += 4; /* find modulus itself */
2079 while (len > 0 && pkblob[pos] == 0)
2081 /* debug(("modulus length is %d\n", len)); */
2084 * Now find the signature integer.
2086 pos = 4+7; /* skip over "ssh-rsa" */
2087 siglen = GET_32BIT(sigblob+pos);
2088 /* debug(("signature length is %d\n", siglen)); */
2090 if (len != siglen) {
2091 unsigned char newlen[4];
2092 ssh2_pkt_addstring_start(pkt);
2093 ssh2_pkt_addstring_data(pkt, (char *)sigblob, pos);
2094 /* dmemdump(sigblob, pos); */
2095 pos += 4; /* point to start of actual sig */
2096 PUT_32BIT(newlen, len);
2097 ssh2_pkt_addstring_data(pkt, (char *)newlen, 4);
2098 /* dmemdump(newlen, 4); */
2100 while (len-- > siglen) {
2101 ssh2_pkt_addstring_data(pkt, (char *)newlen, 1);
2102 /* dmemdump(newlen, 1); */
2104 ssh2_pkt_addstring_data(pkt, (char *)(sigblob+pos), siglen);
2105 /* dmemdump(sigblob+pos, siglen); */
2109 /* Otherwise fall through and do it the easy way. */
2112 ssh2_pkt_addstring_start(pkt);
2113 ssh2_pkt_addstring_data(pkt, (char *)sigblob, sigblob_len);
2117 * Examine the remote side's version string and compare it against
2118 * a list of known buggy implementations.
2120 static void ssh_detect_bugs(Ssh ssh, char *vstring)
2122 char *imp; /* pointer to implementation part */
2124 imp += strcspn(imp, "-");
2126 imp += strcspn(imp, "-");
2129 ssh->remote_bugs = 0;
2131 if (ssh->cfg.sshbug_ignore1 == FORCE_ON ||
2132 (ssh->cfg.sshbug_ignore1 == AUTO &&
2133 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
2134 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
2135 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25") ||
2136 !strcmp(imp, "OSU_1.4alpha3") || !strcmp(imp, "OSU_1.5alpha4")))) {
2138 * These versions don't support SSH1_MSG_IGNORE, so we have
2139 * to use a different defence against password length
2142 ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
2143 logevent("We believe remote version has SSH-1 ignore bug");
2146 if (ssh->cfg.sshbug_plainpw1 == FORCE_ON ||
2147 (ssh->cfg.sshbug_plainpw1 == AUTO &&
2148 (!strcmp(imp, "Cisco-1.25") || !strcmp(imp, "OSU_1.4alpha3")))) {
2150 * These versions need a plain password sent; they can't
2151 * handle having a null and a random length of data after
2154 ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
2155 logevent("We believe remote version needs a plain SSH-1 password");
2158 if (ssh->cfg.sshbug_rsa1 == FORCE_ON ||
2159 (ssh->cfg.sshbug_rsa1 == AUTO &&
2160 (!strcmp(imp, "Cisco-1.25")))) {
2162 * These versions apparently have no clue whatever about
2163 * RSA authentication and will panic and die if they see
2164 * an AUTH_RSA message.
2166 ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
2167 logevent("We believe remote version can't handle SSH-1 RSA authentication");
2170 if (ssh->cfg.sshbug_hmac2 == FORCE_ON ||
2171 (ssh->cfg.sshbug_hmac2 == AUTO &&
2172 !wc_match("* VShell", imp) &&
2173 (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) ||
2174 wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) ||
2175 wc_match("2.1 *", imp)))) {
2177 * These versions have the HMAC bug.
2179 ssh->remote_bugs |= BUG_SSH2_HMAC;
2180 logevent("We believe remote version has SSH-2 HMAC bug");
2183 if (ssh->cfg.sshbug_derivekey2 == FORCE_ON ||
2184 (ssh->cfg.sshbug_derivekey2 == AUTO &&
2185 !wc_match("* VShell", imp) &&
2186 (wc_match("2.0.0*", imp) || wc_match("2.0.10*", imp) ))) {
2188 * These versions have the key-derivation bug (failing to
2189 * include the literal shared secret in the hashes that
2190 * generate the keys).
2192 ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
2193 logevent("We believe remote version has SSH-2 key-derivation bug");
2196 if (ssh->cfg.sshbug_rsapad2 == FORCE_ON ||
2197 (ssh->cfg.sshbug_rsapad2 == AUTO &&
2198 (wc_match("OpenSSH_2.[5-9]*", imp) ||
2199 wc_match("OpenSSH_3.[0-2]*", imp)))) {
2201 * These versions have the SSH-2 RSA padding bug.
2203 ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
2204 logevent("We believe remote version has SSH-2 RSA padding bug");
2207 if (ssh->cfg.sshbug_pksessid2 == FORCE_ON ||
2208 (ssh->cfg.sshbug_pksessid2 == AUTO &&
2209 wc_match("OpenSSH_2.[0-2]*", imp))) {
2211 * These versions have the SSH-2 session-ID bug in
2212 * public-key authentication.
2214 ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID;
2215 logevent("We believe remote version has SSH-2 public-key-session-ID bug");
2218 if (ssh->cfg.sshbug_rekey2 == FORCE_ON ||
2219 (ssh->cfg.sshbug_rekey2 == AUTO &&
2220 (wc_match("OpenSSH_2.[0-4]*", imp) ||
2221 wc_match("OpenSSH_2.5.[0-3]*", imp) ||
2222 wc_match("Sun_SSH_1.0", imp) ||
2223 wc_match("Sun_SSH_1.0.1", imp)))) {
2225 * These versions have the SSH-2 rekey bug.
2227 ssh->remote_bugs |= BUG_SSH2_REKEY;
2228 logevent("We believe remote version has SSH-2 rekey bug");
2233 * The `software version' part of an SSH version string is required
2234 * to contain no spaces or minus signs.
2236 static void ssh_fix_verstring(char *str)
2238 /* Eat "SSH-<protoversion>-". */
2239 assert(*str == 'S'); str++;
2240 assert(*str == 'S'); str++;
2241 assert(*str == 'H'); str++;
2242 assert(*str == '-'); str++;
2243 while (*str && *str != '-') str++;
2244 assert(*str == '-'); str++;
2246 /* Convert minus signs and spaces in the remaining string into
2249 if (*str == '-' || *str == ' ')
2255 static int do_ssh_init(Ssh ssh, unsigned char c)
2257 struct do_ssh_init_state {
2265 crState(do_ssh_init_state);
2267 crBegin(ssh->do_ssh_init_crstate);
2269 /* Search for the string "SSH-" in the input. */
2272 static const int transS[] = { 1, 2, 2, 1 };
2273 static const int transH[] = { 0, 0, 3, 0 };
2274 static const int transminus[] = { 0, 0, 0, -1 };
2276 s->i = transS[s->i];
2278 s->i = transH[s->i];
2280 s->i = transminus[s->i];
2285 crReturn(1); /* get another character */
2289 s->vstring = snewn(s->vstrsize, char);
2290 strcpy(s->vstring, "SSH-");
2294 crReturn(1); /* get another char */
2295 if (s->vslen >= s->vstrsize - 1) {
2297 s->vstring = sresize(s->vstring, s->vstrsize, char);
2299 s->vstring[s->vslen++] = c;
2302 s->version[s->i] = '\0';
2304 } else if (s->i < sizeof(s->version) - 1)
2305 s->version[s->i++] = c;
2306 } else if (c == '\012')
2310 ssh->agentfwd_enabled = FALSE;
2311 ssh->rdpkt2_state.incoming_sequence = 0;
2313 s->vstring[s->vslen] = 0;
2314 s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */
2315 logeventf(ssh, "Server version: %s", s->vstring);
2316 ssh_detect_bugs(ssh, s->vstring);
2319 * Decide which SSH protocol version to support.
2322 /* Anything strictly below "2.0" means protocol 1 is supported. */
2323 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
2324 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
2325 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
2327 if (ssh->cfg.sshprot == 0 && !s->proto1) {
2328 bombout(("SSH protocol version 1 required by user but not provided by server"));
2331 if (ssh->cfg.sshprot == 3 && !s->proto2) {
2332 bombout(("SSH protocol version 2 required by user but not provided by server"));
2339 if (s->proto2 && (ssh->cfg.sshprot >= 2 || !s->proto1)) {
2341 * Construct a v2 version string.
2343 verstring = dupprintf("SSH-2.0-%s\015\012", sshver);
2347 * Construct a v1 version string.
2349 verstring = dupprintf("SSH-%s-%s\012",
2350 (ssh_versioncmp(s->version, "1.5") <= 0 ?
2351 s->version : "1.5"),
2356 ssh_fix_verstring(verstring);
2358 if (ssh->version == 2) {
2360 * Hash our version string and their version string.
2362 SHA_Init(&ssh->exhashbase);
2363 sha_string(&ssh->exhashbase, verstring,
2364 strcspn(verstring, "\015\012"));
2365 sha_string(&ssh->exhashbase, s->vstring,
2366 strcspn(s->vstring, "\015\012"));
2369 * Initialise SSH-2 protocol.
2371 ssh->protocol = ssh2_protocol;
2372 ssh2_protocol_setup(ssh);
2373 ssh->s_rdpkt = ssh2_rdpkt;
2376 * Initialise SSH-1 protocol.
2378 ssh->protocol = ssh1_protocol;
2379 ssh1_protocol_setup(ssh);
2380 ssh->s_rdpkt = ssh1_rdpkt;
2382 logeventf(ssh, "We claim version: %.*s",
2383 strcspn(verstring, "\015\012"), verstring);
2384 sk_write(ssh->s, verstring, strlen(verstring));
2388 logeventf(ssh, "Using SSH protocol version %d", ssh->version);
2390 update_specials_menu(ssh->frontend);
2391 ssh->state = SSH_STATE_BEFORE_SIZE;
2392 ssh->pinger = pinger_new(&ssh->cfg, &ssh_backend, ssh);
2399 static void ssh_process_incoming_data(Ssh ssh,
2400 unsigned char **data, int *datalen)
2402 struct Packet *pktin = ssh->s_rdpkt(ssh, data, datalen);
2404 ssh->protocol(ssh, NULL, 0, pktin);
2405 ssh_free_packet(pktin);
2409 static void ssh_queue_incoming_data(Ssh ssh,
2410 unsigned char **data, int *datalen)
2412 bufchain_add(&ssh->queued_incoming_data, *data, *datalen);
2417 static void ssh_process_queued_incoming_data(Ssh ssh)
2420 unsigned char *data;
2423 while (!ssh->frozen && bufchain_size(&ssh->queued_incoming_data)) {
2424 bufchain_prefix(&ssh->queued_incoming_data, &vdata, &len);
2428 while (!ssh->frozen && len > 0)
2429 ssh_process_incoming_data(ssh, &data, &len);
2432 bufchain_consume(&ssh->queued_incoming_data, origlen - len);
2436 static void ssh_set_frozen(Ssh ssh, int frozen)
2439 sk_set_frozen(ssh->s, frozen);
2440 ssh->frozen = frozen;
2443 static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
2445 crBegin(ssh->ssh_gotdata_crstate);
2448 * To begin with, feed the characters one by one to the
2449 * protocol initialisation / selection function do_ssh_init().
2450 * When that returns 0, we're done with the initial greeting
2451 * exchange and can move on to packet discipline.
2454 int ret; /* need not be kept across crReturn */
2456 crReturnV; /* more data please */
2457 ret = do_ssh_init(ssh, *data);
2465 * We emerge from that loop when the initial negotiation is
2466 * over and we have selected an s_rdpkt function. Now pass
2467 * everything to s_rdpkt, and then pass the resulting packets
2468 * to the proper protocol handler.
2474 * Process queued data if there is any.
2476 ssh_process_queued_incoming_data(ssh);
2479 while (datalen > 0) {
2481 ssh_queue_incoming_data(ssh, &data, &datalen);
2483 ssh_process_incoming_data(ssh, &data, &datalen);
2485 if (ssh->state == SSH_STATE_CLOSED)
2493 static int ssh_do_close(Ssh ssh, int notify_exit)
2496 struct ssh_channel *c;
2498 ssh->state = SSH_STATE_CLOSED;
2499 expire_timer_context(ssh);
2504 notify_remote_exit(ssh->frontend);
2509 * Now we must shut down any port- and X-forwarded channels going
2510 * through this connection.
2512 if (ssh->channels) {
2513 while (NULL != (c = index234(ssh->channels, 0))) {
2516 x11_close(c->u.x11.s);
2519 pfd_close(c->u.pfd.s);
2522 del234(ssh->channels, c); /* moving next one to index 0 */
2523 if (ssh->version == 2)
2524 bufchain_clear(&c->v.v2.outbuffer);
2529 * Go through port-forwardings, and close any associated
2530 * listening sockets.
2532 if (ssh->portfwds) {
2533 struct ssh_portfwd *pf;
2534 while (NULL != (pf = index234(ssh->portfwds, 0))) {
2535 /* Dispose of any listening socket. */
2537 pfd_terminate(pf->local);
2538 del234(ssh->portfwds, pf); /* moving next one to index 0 */
2546 static void ssh_log(Plug plug, int type, SockAddr addr, int port,
2547 const char *error_msg, int error_code)
2549 Ssh ssh = (Ssh) plug;
2550 char addrbuf[256], *msg;
2552 sk_getaddr(addr, addrbuf, lenof(addrbuf));
2555 msg = dupprintf("Connecting to %s port %d", addrbuf, port);
2557 msg = dupprintf("Failed to connect to %s: %s", addrbuf, error_msg);
2563 static int ssh_closing(Plug plug, const char *error_msg, int error_code,
2566 Ssh ssh = (Ssh) plug;
2567 int need_notify = ssh_do_close(ssh, FALSE);
2569 if (!error_msg && !ssh->close_expected) {
2570 error_msg = "Server unexpectedly closed network connection";
2574 notify_remote_exit(ssh->frontend);
2577 /* A socket error has occurred. */
2578 logevent(error_msg);
2579 connection_fatal(ssh->frontend, "%s", error_msg);
2581 logevent("Server closed network connection");
2586 static int ssh_receive(Plug plug, int urgent, char *data, int len)
2588 Ssh ssh = (Ssh) plug;
2589 ssh_gotdata(ssh, (unsigned char *)data, len);
2590 if (ssh->state == SSH_STATE_CLOSED) {
2591 ssh_do_close(ssh, TRUE);
2597 static void ssh_sent(Plug plug, int bufsize)
2599 Ssh ssh = (Ssh) plug;
2601 * If the send backlog on the SSH socket itself clears, we
2602 * should unthrottle the whole world if it was throttled.
2604 if (bufsize < SSH_MAX_BACKLOG)
2605 ssh_throttle_all(ssh, 0, bufsize);
2609 * Connect to specified host and port.
2610 * Returns an error message, or NULL on success.
2611 * Also places the canonical host name into `realhost'. It must be
2612 * freed by the caller.
2614 static const char *connect_to_host(Ssh ssh, char *host, int port,
2615 char **realhost, int nodelay, int keepalive)
2617 static const struct plug_function_table fn_table = {
2628 ssh->savedhost = snewn(1 + strlen(host), char);
2629 if (!ssh->savedhost)
2630 fatalbox("Out of memory");
2631 strcpy(ssh->savedhost, host);
2634 port = 22; /* default ssh port */
2635 ssh->savedport = port;
2640 logeventf(ssh, "Looking up host \"%s\"%s", host,
2641 (ssh->cfg.addressfamily == ADDRTYPE_IPV4 ? " (IPv4)" :
2642 (ssh->cfg.addressfamily == ADDRTYPE_IPV6 ? " (IPv6)" : "")));
2643 addr = name_lookup(host, port, realhost, &ssh->cfg,
2644 ssh->cfg.addressfamily);
2645 if ((err = sk_addr_error(addr)) != NULL) {
2653 ssh->fn = &fn_table;
2654 ssh->s = new_connection(addr, *realhost, port,
2655 0, 1, nodelay, keepalive, (Plug) ssh, &ssh->cfg);
2656 if ((err = sk_socket_error(ssh->s)) != NULL) {
2658 notify_remote_exit(ssh->frontend);
2666 * Throttle or unthrottle the SSH connection.
2668 static void ssh1_throttle(Ssh ssh, int adjust)
2670 int old_count = ssh->v1_throttle_count;
2671 ssh->v1_throttle_count += adjust;
2672 assert(ssh->v1_throttle_count >= 0);
2673 if (ssh->v1_throttle_count && !old_count) {
2674 ssh_set_frozen(ssh, 1);
2675 } else if (!ssh->v1_throttle_count && old_count) {
2676 ssh_set_frozen(ssh, 0);
2681 * Throttle or unthrottle _all_ local data streams (for when sends
2682 * on the SSH connection itself back up).
2684 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
2687 struct ssh_channel *c;
2689 if (enable == ssh->throttled_all)
2691 ssh->throttled_all = enable;
2692 ssh->overall_bufsize = bufsize;
2695 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
2697 case CHAN_MAINSESSION:
2699 * This is treated separately, outside the switch.
2703 x11_override_throttle(c->u.x11.s, enable);
2706 /* Agent channels require no buffer management. */
2709 pfd_override_throttle(c->u.pfd.s, enable);
2716 * Username and password input, abstracted off into routines
2717 * reusable in several places - even between SSH-1 and SSH-2.
2720 /* Set up a username or password input loop on a given buffer. */
2721 static void setup_userpass_input(Ssh ssh, char *buffer, int buflen, int echo)
2723 ssh->userpass_input_buffer = buffer;
2724 ssh->userpass_input_buflen = buflen;
2725 ssh->userpass_input_bufpos = 0;
2726 ssh->userpass_input_echo = echo;
2730 * Process some terminal data in the course of username/password
2731 * input. Returns >0 for success (line of input returned in
2732 * buffer), <0 for failure (user hit ^C/^D, bomb out and exit), 0
2733 * for inconclusive (keep waiting for more input please).
2735 static int process_userpass_input(Ssh ssh, unsigned char *in, int inlen)
2740 switch (c = *in++) {
2743 ssh->userpass_input_buffer[ssh->userpass_input_bufpos] = 0;
2744 ssh->userpass_input_buffer[ssh->userpass_input_buflen-1] = 0;
2749 if (ssh->userpass_input_bufpos > 0) {
2750 if (ssh->userpass_input_echo)
2751 c_write_str(ssh, "\b \b");
2752 ssh->userpass_input_bufpos--;
2757 while (ssh->userpass_input_bufpos > 0) {
2758 if (ssh->userpass_input_echo)
2759 c_write_str(ssh, "\b \b");
2760 ssh->userpass_input_bufpos--;
2769 * This simplistic check for printability is disabled
2770 * when we're doing password input, because some people
2771 * have control characters in their passwords.o
2773 if ((!ssh->userpass_input_echo ||
2774 (c >= ' ' && c <= '~') ||
2775 ((unsigned char) c >= 160))
2776 && ssh->userpass_input_bufpos < ssh->userpass_input_buflen-1) {
2777 ssh->userpass_input_buffer[ssh->userpass_input_bufpos++] = c;
2778 if (ssh->userpass_input_echo)
2779 c_write(ssh, &c, 1);
2787 static void ssh_agent_callback(void *sshv, void *reply, int replylen)
2789 Ssh ssh = (Ssh) sshv;
2791 ssh->agent_response = reply;
2792 ssh->agent_response_len = replylen;
2794 if (ssh->version == 1)
2795 do_ssh1_login(ssh, NULL, -1, NULL);
2797 do_ssh2_authconn(ssh, NULL, -1, NULL);
2800 static void ssh_dialog_callback(void *sshv, int ret)
2802 Ssh ssh = (Ssh) sshv;
2804 ssh->user_response = ret;
2806 if (ssh->version == 1)
2807 do_ssh1_login(ssh, NULL, -1, NULL);
2809 do_ssh2_transport(ssh, NULL, -1, NULL);
2812 * This may have unfrozen the SSH connection, so do a
2815 ssh_process_queued_incoming_data(ssh);
2818 static void ssh_agentf_callback(void *cv, void *reply, int replylen)
2820 struct ssh_channel *c = (struct ssh_channel *)cv;
2822 void *sentreply = reply;
2825 /* Fake SSH_AGENT_FAILURE. */
2826 sentreply = "\0\0\0\1\5";
2829 if (ssh->version == 2) {
2830 ssh2_add_channel_data(c, sentreply, replylen);
2833 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
2834 PKT_INT, c->remoteid,
2837 PKT_DATA, sentreply, replylen,
2846 * Handle the key exchange and user authentication phases.
2848 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
2849 struct Packet *pktin)
2852 unsigned char cookie[8], *ptr;
2853 struct RSAKey servkey, hostkey;
2854 struct MD5Context md5c;
2855 struct do_ssh1_login_state {
2857 unsigned char *rsabuf, *keystr1, *keystr2;
2858 unsigned long supported_ciphers_mask, supported_auths_mask;
2859 int tried_publickey, tried_agent;
2860 int tis_auth_refused, ccard_auth_refused;
2861 unsigned char session_id[16];
2864 void *publickey_blob;
2865 int publickey_bloblen;
2871 unsigned char request[5], *response, *p;
2881 crState(do_ssh1_login_state);
2883 crBegin(ssh->do_ssh1_login_crstate);
2888 if (pktin->type != SSH1_SMSG_PUBLIC_KEY) {
2889 bombout(("Public key packet not received"));
2893 logevent("Received public keys");
2895 ptr = ssh_pkt_getdata(pktin, 8);
2897 bombout(("SSH-1 public key packet stopped before random cookie"));
2900 memcpy(cookie, ptr, 8);
2902 if (!ssh1_pkt_getrsakey(pktin, &servkey, &s->keystr1) ||
2903 !ssh1_pkt_getrsakey(pktin, &hostkey, &s->keystr2)) {
2904 bombout(("Failed to read SSH-1 public keys from public key packet"));
2909 * Log the host key fingerprint.
2913 logevent("Host key fingerprint is:");
2914 strcpy(logmsg, " ");
2915 hostkey.comment = NULL;
2916 rsa_fingerprint(logmsg + strlen(logmsg),
2917 sizeof(logmsg) - strlen(logmsg), &hostkey);
2921 ssh->v1_remote_protoflags = ssh_pkt_getuint32(pktin);
2922 s->supported_ciphers_mask = ssh_pkt_getuint32(pktin);
2923 s->supported_auths_mask = ssh_pkt_getuint32(pktin);
2925 ssh->v1_local_protoflags =
2926 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
2927 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
2930 MD5Update(&md5c, s->keystr2, hostkey.bytes);
2931 MD5Update(&md5c, s->keystr1, servkey.bytes);
2932 MD5Update(&md5c, cookie, 8);
2933 MD5Final(s->session_id, &md5c);
2935 for (i = 0; i < 32; i++)
2936 ssh->session_key[i] = random_byte();
2939 * Verify that the `bits' and `bytes' parameters match.
2941 if (hostkey.bits > hostkey.bytes * 8 ||
2942 servkey.bits > servkey.bytes * 8) {
2943 bombout(("SSH-1 public keys were badly formatted"));
2947 s->len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
2949 s->rsabuf = snewn(s->len, unsigned char);
2951 fatalbox("Out of memory");
2954 * Verify the host key.
2958 * First format the key into a string.
2960 int len = rsastr_len(&hostkey);
2961 char fingerprint[100];
2962 char *keystr = snewn(len, char);
2964 fatalbox("Out of memory");
2965 rsastr_fmt(keystr, &hostkey);
2966 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
2968 ssh_set_frozen(ssh, 1);
2969 s->dlgret = verify_ssh_host_key(ssh->frontend,
2970 ssh->savedhost, ssh->savedport,
2971 "rsa", keystr, fingerprint,
2972 ssh_dialog_callback, ssh);
2974 if (s->dlgret < 0) {
2978 bombout(("Unexpected data from server while waiting"
2979 " for user host key response"));
2982 } while (pktin || inlen > 0);
2983 s->dlgret = ssh->user_response;
2985 ssh_set_frozen(ssh, 0);
2987 if (s->dlgret == 0) {
2988 ssh->close_expected = TRUE;
2989 ssh_closing((Plug)ssh, NULL, 0, 0);
2994 for (i = 0; i < 32; i++) {
2995 s->rsabuf[i] = ssh->session_key[i];
2997 s->rsabuf[i] ^= s->session_id[i];
3000 if (hostkey.bytes > servkey.bytes) {
3001 ret = rsaencrypt(s->rsabuf, 32, &servkey);
3003 ret = rsaencrypt(s->rsabuf, servkey.bytes, &hostkey);
3005 ret = rsaencrypt(s->rsabuf, 32, &hostkey);
3007 ret = rsaencrypt(s->rsabuf, hostkey.bytes, &servkey);
3010 bombout(("SSH-1 public key encryptions failed due to bad formatting"));
3014 logevent("Encrypted session key");
3017 int cipher_chosen = 0, warn = 0;
3018 char *cipher_string = NULL;
3020 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
3021 int next_cipher = ssh->cfg.ssh_cipherlist[i];
3022 if (next_cipher == CIPHER_WARN) {
3023 /* If/when we choose a cipher, warn about it */
3025 } else if (next_cipher == CIPHER_AES) {
3026 /* XXX Probably don't need to mention this. */
3027 logevent("AES not supported in SSH-1, skipping");
3029 switch (next_cipher) {
3030 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
3031 cipher_string = "3DES"; break;
3032 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
3033 cipher_string = "Blowfish"; break;
3034 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
3035 cipher_string = "single-DES"; break;
3037 if (s->supported_ciphers_mask & (1 << s->cipher_type))
3041 if (!cipher_chosen) {
3042 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
3043 bombout(("Server violates SSH-1 protocol by not "
3044 "supporting 3DES encryption"));
3046 /* shouldn't happen */
3047 bombout(("No supported ciphers found"));
3051 /* Warn about chosen cipher if necessary. */
3053 ssh_set_frozen(ssh, 1);
3054 s->dlgret = askalg(ssh->frontend, "cipher", cipher_string,
3055 ssh_dialog_callback, ssh);
3056 if (s->dlgret < 0) {
3060 bombout(("Unexpected data from server while waiting"
3061 " for user response"));
3064 } while (pktin || inlen > 0);
3065 s->dlgret = ssh->user_response;
3067 ssh_set_frozen(ssh, 0);
3068 if (s->dlgret == 0) {
3069 ssh->close_expected = TRUE;
3070 ssh_closing((Plug)ssh, NULL, 0, 0);
3076 switch (s->cipher_type) {
3077 case SSH_CIPHER_3DES:
3078 logevent("Using 3DES encryption");
3080 case SSH_CIPHER_DES:
3081 logevent("Using single-DES encryption");
3083 case SSH_CIPHER_BLOWFISH:
3084 logevent("Using Blowfish encryption");
3088 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
3089 PKT_CHAR, s->cipher_type,
3090 PKT_DATA, cookie, 8,
3091 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
3092 PKT_DATA, s->rsabuf, s->len,
3093 PKT_INT, ssh->v1_local_protoflags, PKT_END);
3095 logevent("Trying to enable encryption...");
3099 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
3100 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
3102 ssh->v1_cipher_ctx = ssh->cipher->make_context();
3103 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
3104 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
3106 ssh->crcda_ctx = crcda_make_context();
3107 logevent("Installing CRC compensation attack detector");
3109 if (servkey.modulus) {
3110 sfree(servkey.modulus);
3111 servkey.modulus = NULL;
3113 if (servkey.exponent) {
3114 sfree(servkey.exponent);
3115 servkey.exponent = NULL;
3117 if (hostkey.modulus) {
3118 sfree(hostkey.modulus);
3119 hostkey.modulus = NULL;
3121 if (hostkey.exponent) {
3122 sfree(hostkey.exponent);
3123 hostkey.exponent = NULL;
3127 if (pktin->type != SSH1_SMSG_SUCCESS) {
3128 bombout(("Encryption not successfully enabled"));
3132 logevent("Successfully started encryption");
3136 if (!*ssh->cfg.username) {
3137 if (ssh_get_line && !ssh_getline_pw_only) {
3138 if (!ssh_get_line("login as: ",
3139 s->username, sizeof(s->username), FALSE)) {
3141 * get_line failed to get a username.
3144 logevent("No username provided. Abandoning session.");
3145 ssh->close_expected = TRUE;
3146 ssh_closing((Plug)ssh, NULL, 0, 0);
3150 int ret; /* need not be kept over crReturn */
3151 c_write_str(ssh, "login as: ");
3154 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
3156 crWaitUntil(!pktin);
3157 ret = process_userpass_input(ssh, in, inlen);
3161 c_write_str(ssh, "\r\n");
3164 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
3165 s->username[sizeof(s->username)-1] = '\0';
3168 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, s->username, PKT_END);
3170 char userlog[22 + sizeof(s->username)];
3171 sprintf(userlog, "Sent username \"%s\"", s->username);
3173 if (flags & FLAG_INTERACTIVE &&
3174 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
3175 strcat(userlog, "\r\n");
3176 c_write_str(ssh, userlog);
3183 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA)) {
3184 /* We must not attempt PK auth. Pretend we've already tried it. */
3185 s->tried_publickey = s->tried_agent = 1;
3187 s->tried_publickey = s->tried_agent = 0;
3189 s->tis_auth_refused = s->ccard_auth_refused = 0;
3190 /* Load the public half of ssh->cfg.keyfile so we notice if it's in Pageant */
3191 if (!filename_is_null(ssh->cfg.keyfile)) {
3192 if (!rsakey_pubblob(&ssh->cfg.keyfile,
3193 &s->publickey_blob, &s->publickey_bloblen, NULL))
3194 s->publickey_blob = NULL;
3196 s->publickey_blob = NULL;
3198 while (pktin->type == SSH1_SMSG_FAILURE) {
3199 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
3201 if (agent_exists() && !s->tried_agent) {
3203 * Attempt RSA authentication using Pageant.
3209 logevent("Pageant is running. Requesting keys.");
3211 /* Request the keys held by the agent. */
3212 PUT_32BIT(s->request, 1);
3213 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
3214 if (!agent_query(s->request, 5, &r, &s->responselen,
3215 ssh_agent_callback, ssh)) {
3219 bombout(("Unexpected data from server while waiting"
3220 " for agent response"));
3223 } while (pktin || inlen > 0);
3224 r = ssh->agent_response;
3225 s->responselen = ssh->agent_response_len;
3227 s->response = (unsigned char *) r;
3228 if (s->response && s->responselen >= 5 &&
3229 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
3230 s->p = s->response + 5;
3231 s->nkeys = GET_32BIT(s->p);
3233 logeventf(ssh, "Pageant has %d SSH-1 keys", s->nkeys);
3234 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
3235 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
3236 if (s->publickey_blob &&
3237 !memcmp(s->p, s->publickey_blob,
3238 s->publickey_bloblen)) {
3239 logevent("This key matches configured key file");
3240 s->tried_publickey = 1;
3245 do { /* do while (0) to make breaking easy */
3246 n = ssh1_read_bignum
3247 (s->p, s->responselen-(s->p-s->response),
3252 n = ssh1_read_bignum
3253 (s->p, s->responselen-(s->p-s->response),
3258 if (s->responselen - (s->p-s->response) < 4)
3260 s->commentlen = GET_32BIT(s->p);
3262 if (s->responselen - (s->p-s->response) <
3265 s->commentp = (char *)s->p;
3266 s->p += s->commentlen;
3270 logevent("Pageant key list packet was truncated");
3274 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3275 PKT_BIGNUM, s->key.modulus, PKT_END);
3277 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
3278 logevent("Key refused");
3281 logevent("Received RSA challenge");
3282 if ((s->challenge = ssh1_pkt_getmp(pktin)) == NULL) {
3283 bombout(("Server's RSA challenge was badly formatted"));
3288 char *agentreq, *q, *ret;
3291 len = 1 + 4; /* message type, bit count */
3292 len += ssh1_bignum_length(s->key.exponent);
3293 len += ssh1_bignum_length(s->key.modulus);
3294 len += ssh1_bignum_length(s->challenge);
3295 len += 16; /* session id */
3296 len += 4; /* response format */
3297 agentreq = snewn(4 + len, char);
3298 PUT_32BIT(agentreq, len);
3300 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
3301 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
3303 q += ssh1_write_bignum(q, s->key.exponent);
3304 q += ssh1_write_bignum(q, s->key.modulus);
3305 q += ssh1_write_bignum(q, s->challenge);
3306 memcpy(q, s->session_id, 16);
3308 PUT_32BIT(q, 1); /* response format */
3309 if (!agent_query(agentreq, len + 4, &vret, &retlen,
3310 ssh_agent_callback, ssh)) {
3315 bombout(("Unexpected data from server"
3316 " while waiting for agent"
3320 } while (pktin || inlen > 0);
3321 vret = ssh->agent_response;
3322 retlen = ssh->agent_response_len;
3327 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
3328 logevent("Sending Pageant's response");
3329 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
3330 PKT_DATA, ret + 5, 16,
3334 if (pktin->type == SSH1_SMSG_SUCCESS) {
3336 ("Pageant's response accepted");
3337 if (flags & FLAG_VERBOSE) {
3338 c_write_str(ssh, "Authenticated using"
3340 c_write(ssh, s->commentp,
3342 c_write_str(ssh, "\" from agent\r\n");
3347 ("Pageant's response not accepted");
3350 ("Pageant failed to answer challenge");
3354 logevent("No reply received from Pageant");
3357 freebn(s->key.exponent);
3358 freebn(s->key.modulus);
3359 freebn(s->challenge);
3368 if (!filename_is_null(ssh->cfg.keyfile) && !s->tried_publickey)
3369 s->pwpkt_type = SSH1_CMSG_AUTH_RSA;
3371 if (ssh->cfg.try_tis_auth &&
3372 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
3373 !s->tis_auth_refused) {
3374 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
3375 logevent("Requested TIS authentication");
3376 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
3378 if (pktin->type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
3379 logevent("TIS authentication declined");
3380 if (flags & FLAG_INTERACTIVE)
3381 c_write_str(ssh, "TIS authentication refused.\r\n");
3382 s->tis_auth_refused = 1;
3388 ssh_pkt_getstring(pktin, &challenge, &challengelen);
3390 bombout(("TIS challenge packet was badly formed"));
3393 c_write_str(ssh, "Using TIS authentication.\r\n");
3394 logevent("Received TIS challenge");
3395 if (challengelen > sizeof(s->prompt) - 1)
3396 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
3397 memcpy(s->prompt, challenge, challengelen);
3398 /* Prompt heuristic comes from OpenSSH */
3399 strncpy(s->prompt + challengelen,
3400 memchr(s->prompt, '\n', challengelen) ?
3401 "": "\r\nResponse: ",
3402 (sizeof s->prompt) - challengelen);
3403 s->prompt[(sizeof s->prompt) - 1] = '\0';
3406 if (ssh->cfg.try_tis_auth &&
3407 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
3408 !s->ccard_auth_refused) {
3409 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
3410 logevent("Requested CryptoCard authentication");
3411 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
3413 if (pktin->type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
3414 logevent("CryptoCard authentication declined");
3415 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
3416 s->ccard_auth_refused = 1;
3422 ssh_pkt_getstring(pktin, &challenge, &challengelen);
3424 bombout(("CryptoCard challenge packet was badly formed"));
3427 c_write_str(ssh, "Using CryptoCard authentication.\r\n");
3428 logevent("Received CryptoCard challenge");
3429 if (challengelen > sizeof(s->prompt) - 1)
3430 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
3431 memcpy(s->prompt, challenge, challengelen);
3432 strncpy(s->prompt + challengelen,
3433 memchr(s->prompt, '\n', challengelen) ?
3434 "" : "\r\nResponse: ",
3435 sizeof(s->prompt) - challengelen);
3436 s->prompt[sizeof(s->prompt) - 1] = '\0';
3439 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
3440 sprintf(s->prompt, "%.90s@%.90s's password: ",
3441 s->username, ssh->savedhost);
3443 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
3444 char *comment = NULL;
3446 if (flags & FLAG_VERBOSE)
3447 c_write_str(ssh, "Trying public key authentication.\r\n");
3448 logeventf(ssh, "Trying public key \"%s\"",
3449 filename_to_str(&ssh->cfg.keyfile));
3450 type = key_type(&ssh->cfg.keyfile);
3451 if (type != SSH_KEYTYPE_SSH1) {
3452 char *msg = dupprintf("Key is of wrong type (%s)",
3453 key_type_to_str(type));
3455 c_write_str(ssh, msg);
3456 c_write_str(ssh, "\r\n");
3458 s->tried_publickey = 1;
3461 if (!rsakey_encrypted(&ssh->cfg.keyfile, &comment)) {
3462 if (flags & FLAG_VERBOSE)
3463 c_write_str(ssh, "No passphrase required.\r\n");
3466 sprintf(s->prompt, "Passphrase for key \"%.100s\": ", comment);
3471 * Show password prompt, having first obtained it via a TIS
3472 * or CryptoCard exchange if we're doing TIS or CryptoCard
3476 if (!ssh_get_line(s->prompt, s->password,
3477 sizeof(s->password), TRUE)) {
3479 * get_line failed to get a password (for example
3480 * because one was supplied on the command line
3481 * which has already failed to work). Terminate.
3483 send_packet(ssh, SSH1_MSG_DISCONNECT,
3484 PKT_STR, "No more passwords available to try",
3486 logevent("Unable to authenticate");
3487 connection_fatal(ssh->frontend, "Unable to authenticate");
3488 ssh->close_expected = TRUE;
3489 ssh_closing((Plug)ssh, NULL, 0, 0);
3493 /* Prompt may have come from server. We've munged it a bit, so
3494 * we know it to be zero-terminated at least once. */
3495 int ret; /* need not be saved over crReturn */
3496 c_write_untrusted(ssh, s->prompt, strlen(s->prompt));
3499 setup_userpass_input(ssh, s->password, sizeof(s->password), 0);
3501 crWaitUntil(!pktin);
3502 ret = process_userpass_input(ssh, in, inlen);
3506 c_write_str(ssh, "\r\n");
3510 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
3512 * Try public key authentication with the specified
3515 s->tried_publickey = 1;
3518 const char *error = NULL;
3519 int ret = loadrsakey(&ssh->cfg.keyfile, &s->key, s->password,
3522 c_write_str(ssh, "Couldn't load private key from ");
3523 c_write_str(ssh, filename_to_str(&ssh->cfg.keyfile));
3524 c_write_str(ssh, " (");
3525 c_write_str(ssh, error);
3526 c_write_str(ssh, ").\r\n");
3527 continue; /* go and try password */
3530 c_write_str(ssh, "Wrong passphrase.\r\n");
3531 s->tried_publickey = 0;
3532 continue; /* try again */
3537 * Send a public key attempt.
3539 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3540 PKT_BIGNUM, s->key.modulus, PKT_END);
3543 if (pktin->type == SSH1_SMSG_FAILURE) {
3544 c_write_str(ssh, "Server refused our public key.\r\n");
3545 continue; /* go and try password */
3547 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
3548 bombout(("Bizarre response to offer of public key"));
3554 unsigned char buffer[32];
3555 Bignum challenge, response;
3557 if ((challenge = ssh1_pkt_getmp(pktin)) == NULL) {
3558 bombout(("Server's RSA challenge was badly formatted"));
3561 response = rsadecrypt(challenge, &s->key);
3562 freebn(s->key.private_exponent);/* burn the evidence */
3564 for (i = 0; i < 32; i++) {
3565 buffer[i] = bignum_byte(response, 31 - i);
3569 MD5Update(&md5c, buffer, 32);
3570 MD5Update(&md5c, s->session_id, 16);
3571 MD5Final(buffer, &md5c);
3573 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
3574 PKT_DATA, buffer, 16, PKT_END);
3581 if (pktin->type == SSH1_SMSG_FAILURE) {
3582 if (flags & FLAG_VERBOSE)
3583 c_write_str(ssh, "Failed to authenticate with"
3584 " our public key.\r\n");
3585 continue; /* go and try password */
3586 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
3587 bombout(("Bizarre response to RSA authentication response"));
3591 break; /* we're through! */
3593 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
3595 * Defence against traffic analysis: we send a
3596 * whole bunch of packets containing strings of
3597 * different lengths. One of these strings is the
3598 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
3599 * The others are all random data in
3600 * SSH1_MSG_IGNORE packets. This way a passive
3601 * listener can't tell which is the password, and
3602 * hence can't deduce the password length.
3604 * Anybody with a password length greater than 16
3605 * bytes is going to have enough entropy in their
3606 * password that a listener won't find it _that_
3607 * much help to know how long it is. So what we'll
3610 * - if password length < 16, we send 15 packets
3611 * containing string lengths 1 through 15
3613 * - otherwise, we let N be the nearest multiple
3614 * of 8 below the password length, and send 8
3615 * packets containing string lengths N through
3616 * N+7. This won't obscure the order of
3617 * magnitude of the password length, but it will
3618 * introduce a bit of extra uncertainty.
3620 * A few servers (the old 1.2.18 through 1.2.22)
3621 * can't deal with SSH1_MSG_IGNORE. For these
3622 * servers, we need an alternative defence. We make
3623 * use of the fact that the password is interpreted
3624 * as a C string: so we can append a NUL, then some
3627 * One server (a Cisco one) can deal with neither
3628 * SSH1_MSG_IGNORE _nor_ a padded password string.
3629 * For this server we are left with no defences
3630 * against password length sniffing.
3632 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) {
3634 * The server can deal with SSH1_MSG_IGNORE, so
3635 * we can use the primary defence.
3637 int bottom, top, pwlen, i;
3640 pwlen = strlen(s->password);
3642 bottom = 0; /* zero length passwords are OK! :-) */
3645 bottom = pwlen & ~7;
3649 assert(pwlen >= bottom && pwlen <= top);
3651 randomstr = snewn(top + 1, char);
3653 for (i = bottom; i <= top; i++) {
3655 defer_packet(ssh, s->pwpkt_type,
3656 PKTT_PASSWORD, PKT_STR, s->password,
3657 PKTT_OTHER, PKT_END);
3659 for (j = 0; j < i; j++) {
3661 randomstr[j] = random_byte();
3662 } while (randomstr[j] == '\0');
3664 randomstr[i] = '\0';
3665 defer_packet(ssh, SSH1_MSG_IGNORE,
3666 PKT_STR, randomstr, PKT_END);
3669 logevent("Sending password with camouflage packets");
3670 ssh_pkt_defersend(ssh);
3673 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
3675 * The server can't deal with SSH1_MSG_IGNORE
3676 * but can deal with padded passwords, so we
3677 * can use the secondary defence.
3683 len = strlen(s->password);
3684 if (len < sizeof(string)) {
3686 strcpy(string, s->password);
3687 len++; /* cover the zero byte */
3688 while (len < sizeof(string)) {
3689 string[len++] = (char) random_byte();
3694 logevent("Sending length-padded password");
3695 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
3696 PKT_INT, len, PKT_DATA, ss, len,
3697 PKTT_OTHER, PKT_END);
3700 * The server has _both_
3701 * BUG_CHOKES_ON_SSH1_IGNORE and
3702 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
3703 * therefore nothing we can do.
3706 len = strlen(s->password);
3707 logevent("Sending unpadded password");
3708 send_packet(ssh, s->pwpkt_type,
3709 PKTT_PASSWORD, PKT_INT, len,
3710 PKT_DATA, s->password, len,
3711 PKTT_OTHER, PKT_END);
3714 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
3715 PKT_STR, s->password, PKTT_OTHER, PKT_END);
3718 logevent("Sent password");
3719 memset(s->password, 0, strlen(s->password));
3721 if (pktin->type == SSH1_SMSG_FAILURE) {
3722 if (flags & FLAG_VERBOSE)
3723 c_write_str(ssh, "Access denied\r\n");
3724 logevent("Authentication refused");
3725 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
3726 bombout(("Strange packet received, type %d", pktin->type));
3731 logevent("Authentication successful");
3736 void sshfwd_close(struct ssh_channel *c)
3740 if (ssh->state == SSH_STATE_CLOSED)
3743 if (c && !c->closes) {
3745 * If halfopen is true, we have sent
3746 * CHANNEL_OPEN for this channel, but it hasn't even been
3747 * acknowledged by the server. So we must set a close flag
3748 * on it now, and then when the server acks the channel
3749 * open, we can close it then.
3752 if (ssh->version == 1) {
3753 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
3756 struct Packet *pktout;
3757 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
3758 ssh2_pkt_adduint32(pktout, c->remoteid);
3759 ssh2_pkt_send(ssh, pktout);
3762 c->closes = 1; /* sent MSG_CLOSE */
3763 if (c->type == CHAN_X11) {
3765 logevent("Forwarded X11 connection terminated");
3766 } else if (c->type == CHAN_SOCKDATA ||
3767 c->type == CHAN_SOCKDATA_DORMANT) {
3769 logevent("Forwarded port closed");
3774 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
3778 if (ssh->state == SSH_STATE_CLOSED)
3781 if (ssh->version == 1) {
3782 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
3783 PKT_INT, c->remoteid,
3785 PKT_INT, len, PKT_DATA, buf, len,
3786 PKTT_OTHER, PKT_END);
3788 * In SSH-1 we can return 0 here - implying that forwarded
3789 * connections are never individually throttled - because
3790 * the only circumstance that can cause throttling will be
3791 * the whole SSH connection backing up, in which case
3792 * _everything_ will be throttled as a whole.
3796 ssh2_add_channel_data(c, buf, len);
3797 return ssh2_try_send(c);
3801 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
3805 if (ssh->state == SSH_STATE_CLOSED)
3808 if (ssh->version == 1) {
3809 if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
3810 c->v.v1.throttling = 0;
3811 ssh1_throttle(ssh, -1);
3814 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
3818 static void ssh_queueing_handler(Ssh ssh, struct Packet *pktin)
3820 struct queued_handler *qh = ssh->qhead;
3824 assert(pktin->type == qh->msg1 || pktin->type == qh->msg2);
3827 assert(ssh->packet_dispatch[qh->msg1] == ssh_queueing_handler);
3828 ssh->packet_dispatch[qh->msg1] = NULL;
3831 assert(ssh->packet_dispatch[qh->msg2] == ssh_queueing_handler);
3832 ssh->packet_dispatch[qh->msg2] = NULL;
3836 ssh->qhead = qh->next;
3838 if (ssh->qhead->msg1 > 0) {
3839 assert(ssh->packet_dispatch[ssh->qhead->msg1] == NULL);
3840 ssh->packet_dispatch[ssh->qhead->msg1] = ssh_queueing_handler;
3842 if (ssh->qhead->msg2 > 0) {
3843 assert(ssh->packet_dispatch[ssh->qhead->msg2] == NULL);
3844 ssh->packet_dispatch[ssh->qhead->msg2] = ssh_queueing_handler;
3847 ssh->qhead = ssh->qtail = NULL;
3848 ssh->packet_dispatch[pktin->type] = NULL;
3851 qh->handler(ssh, pktin, qh->ctx);
3856 static void ssh_queue_handler(Ssh ssh, int msg1, int msg2,
3857 chandler_fn_t handler, void *ctx)
3859 struct queued_handler *qh;
3861 qh = snew(struct queued_handler);
3864 qh->handler = handler;
3868 if (ssh->qtail == NULL) {
3872 assert(ssh->packet_dispatch[qh->msg1] == NULL);
3873 ssh->packet_dispatch[qh->msg1] = ssh_queueing_handler;
3876 assert(ssh->packet_dispatch[qh->msg2] == NULL);
3877 ssh->packet_dispatch[qh->msg2] = ssh_queueing_handler;
3880 ssh->qtail->next = qh;
3885 static void ssh_rportfwd_succfail(Ssh ssh, struct Packet *pktin, void *ctx)
3887 struct ssh_rportfwd *rpf, *pf = (struct ssh_rportfwd *)ctx;
3889 if (pktin->type == (ssh->version == 1 ? SSH1_SMSG_SUCCESS :
3890 SSH2_MSG_REQUEST_SUCCESS)) {
3891 logeventf(ssh, "Remote port forwarding from %s enabled",
3894 logeventf(ssh, "Remote port forwarding from %s refused",
3897 rpf = del234(ssh->rportfwds, pf);
3903 static void ssh_setup_portfwd(Ssh ssh, const Config *cfg)
3905 const char *portfwd_strptr = cfg->portfwd;
3906 struct ssh_portfwd *epf;
3909 if (!ssh->portfwds) {
3910 ssh->portfwds = newtree234(ssh_portcmp);
3913 * Go through the existing port forwardings and tag them
3914 * with status==DESTROY. Any that we want to keep will be
3915 * re-enabled (status==KEEP) as we go through the
3916 * configuration and find out which bits are the same as
3919 struct ssh_portfwd *epf;
3921 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
3922 epf->status = DESTROY;
3925 while (*portfwd_strptr) {
3926 char address_family, type;
3927 int sport,dport,sserv,dserv;
3928 char sports[256], dports[256], saddr[256], host[256];
3931 address_family = 'A';
3933 if (*portfwd_strptr == 'A' ||
3934 *portfwd_strptr == '4' ||
3935 *portfwd_strptr == '6')
3936 address_family = *portfwd_strptr++;
3937 if (*portfwd_strptr == 'L' ||
3938 *portfwd_strptr == 'R' ||
3939 *portfwd_strptr == 'D')
3940 type = *portfwd_strptr++;
3945 while (*portfwd_strptr && *portfwd_strptr != '\t') {
3946 if (*portfwd_strptr == ':') {
3948 * We've seen a colon in the middle of the
3949 * source port number. This means that
3950 * everything we've seen until now is the
3951 * source _address_, so we'll move it into
3952 * saddr and start sports from the beginning
3957 if (ssh->version == 1 && type == 'R') {
3958 logeventf(ssh, "SSH-1 cannot handle remote source address "
3959 "spec \"%s\"; ignoring", sports);
3961 strcpy(saddr, sports);
3964 if (n < lenof(sports)-1) sports[n++] = *portfwd_strptr++;
3968 if (*portfwd_strptr == '\t')
3971 while (*portfwd_strptr && *portfwd_strptr != ':') {
3972 if (n < lenof(host)-1) host[n++] = *portfwd_strptr++;
3975 if (*portfwd_strptr == ':')
3978 while (*portfwd_strptr) {
3979 if (n < lenof(dports)-1) dports[n++] = *portfwd_strptr++;
3983 dport = atoi(dports);
3987 dport = net_service_lookup(dports);
3989 logeventf(ssh, "Service lookup failed for destination"
3990 " port \"%s\"", dports);
3994 while (*portfwd_strptr) portfwd_strptr++;
3998 portfwd_strptr++; /* eat the NUL and move to next one */
4000 sport = atoi(sports);
4004 sport = net_service_lookup(sports);
4006 logeventf(ssh, "Service lookup failed for source"
4007 " port \"%s\"", sports);
4010 if (sport && dport) {
4011 /* Set up a description of the source port. */
4012 struct ssh_portfwd *pfrec, *epfrec;
4014 pfrec = snew(struct ssh_portfwd);
4016 pfrec->saddr = *saddr ? dupstr(saddr) : NULL;
4017 pfrec->sserv = sserv ? dupstr(sports) : NULL;
4018 pfrec->sport = sport;
4019 pfrec->daddr = *host ? dupstr(host) : NULL;
4020 pfrec->dserv = dserv ? dupstr(dports) : NULL;
4021 pfrec->dport = dport;
4022 pfrec->local = NULL;
4023 pfrec->remote = NULL;
4024 pfrec->addressfamily = (address_family == '4' ? ADDRTYPE_IPV4 :
4025 address_family == '6' ? ADDRTYPE_IPV6 :
4028 epfrec = add234(ssh->portfwds, pfrec);
4029 if (epfrec != pfrec) {
4031 * We already have a port forwarding with precisely
4032 * these parameters. Hence, no need to do anything;
4033 * simply tag the existing one as KEEP.
4035 epfrec->status = KEEP;
4036 free_portfwd(pfrec);
4038 pfrec->status = CREATE;
4044 * Now go through and destroy any port forwardings which were
4047 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
4048 if (epf->status == DESTROY) {
4051 message = dupprintf("%s port forwarding from %s%s%d",
4052 epf->type == 'L' ? "local" :
4053 epf->type == 'R' ? "remote" : "dynamic",
4054 epf->saddr ? epf->saddr : "",
4055 epf->saddr ? ":" : "",
4058 if (epf->type != 'D') {
4059 char *msg2 = dupprintf("%s to %s:%d", message,
4060 epf->daddr, epf->dport);
4065 logeventf(ssh, "Cancelling %s", message);
4069 struct ssh_rportfwd *rpf = epf->remote;
4070 struct Packet *pktout;
4073 * Cancel the port forwarding at the server
4076 if (ssh->version == 1) {
4078 * We cannot cancel listening ports on the
4079 * server side in SSH-1! There's no message
4080 * to support it. Instead, we simply remove
4081 * the rportfwd record from the local end
4082 * so that any connections the server tries
4083 * to make on it are rejected.
4086 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
4087 ssh2_pkt_addstring(pktout, "cancel-tcpip-forward");
4088 ssh2_pkt_addbool(pktout, 0);/* _don't_ want reply */
4090 ssh2_pkt_addstring(pktout, epf->saddr);
4091 } else if (ssh->cfg.rport_acceptall) {
4092 /* XXX: ssh->cfg.rport_acceptall may not represent
4093 * what was used to open the original connection,
4094 * since it's reconfigurable. */
4095 ssh2_pkt_addstring(pktout, "0.0.0.0");
4097 ssh2_pkt_addstring(pktout, "127.0.0.1");
4099 ssh2_pkt_adduint32(pktout, epf->sport);
4100 ssh2_pkt_send(ssh, pktout);
4103 del234(ssh->rportfwds, rpf);
4105 } else if (epf->local) {
4106 pfd_terminate(epf->local);
4109 delpos234(ssh->portfwds, i);
4111 i--; /* so we don't skip one in the list */
4115 * And finally, set up any new port forwardings (status==CREATE).
4117 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
4118 if (epf->status == CREATE) {
4119 char *sportdesc, *dportdesc;
4120 sportdesc = dupprintf("%s%s%s%s%d%s",
4121 epf->saddr ? epf->saddr : "",
4122 epf->saddr ? ":" : "",
4123 epf->sserv ? epf->sserv : "",
4124 epf->sserv ? "(" : "",
4126 epf->sserv ? ")" : "");
4127 if (epf->type == 'D') {
4130 dportdesc = dupprintf("%s:%s%s%d%s",
4132 epf->dserv ? epf->dserv : "",
4133 epf->dserv ? "(" : "",
4135 epf->dserv ? ")" : "");
4138 if (epf->type == 'L') {
4139 const char *err = pfd_addforward(epf->daddr, epf->dport,
4140 epf->saddr, epf->sport,
4143 epf->addressfamily);
4145 logeventf(ssh, "Local %sport %s forwarding to %s%s%s",
4146 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
4147 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
4148 sportdesc, dportdesc,
4149 err ? " failed: " : "", err ? err : "");
4150 } else if (epf->type == 'D') {
4151 const char *err = pfd_addforward(NULL, -1,
4152 epf->saddr, epf->sport,
4155 epf->addressfamily);
4157 logeventf(ssh, "Local %sport %s SOCKS dynamic forwarding%s%s",
4158 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
4159 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
4161 err ? " failed: " : "", err ? err : "");
4163 struct ssh_rportfwd *pf;
4166 * Ensure the remote port forwardings tree exists.
4168 if (!ssh->rportfwds) {
4169 if (ssh->version == 1)
4170 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
4172 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
4175 pf = snew(struct ssh_rportfwd);
4176 strncpy(pf->dhost, epf->daddr, lenof(pf->dhost)-1);
4177 pf->dhost[lenof(pf->dhost)-1] = '\0';
4178 pf->dport = epf->dport;
4179 pf->sport = epf->sport;
4180 if (add234(ssh->rportfwds, pf) != pf) {
4181 logeventf(ssh, "Duplicate remote port forwarding to %s:%d",
4182 epf->daddr, epf->dport);
4185 logeventf(ssh, "Requesting remote port %s"
4186 " forward to %s", sportdesc, dportdesc);
4188 pf->sportdesc = sportdesc;
4193 if (ssh->version == 1) {
4194 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
4195 PKT_INT, epf->sport,
4196 PKT_STR, epf->daddr,
4197 PKT_INT, epf->dport,
4199 ssh_queue_handler(ssh, SSH1_SMSG_SUCCESS,
4201 ssh_rportfwd_succfail, pf);
4203 struct Packet *pktout;
4204 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
4205 ssh2_pkt_addstring(pktout, "tcpip-forward");
4206 ssh2_pkt_addbool(pktout, 1);/* want reply */
4208 ssh2_pkt_addstring(pktout, epf->saddr);
4209 } else if (cfg->rport_acceptall) {
4210 ssh2_pkt_addstring(pktout, "0.0.0.0");
4212 ssh2_pkt_addstring(pktout, "127.0.0.1");
4214 ssh2_pkt_adduint32(pktout, epf->sport);
4215 ssh2_pkt_send(ssh, pktout);
4217 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS,
4218 SSH2_MSG_REQUEST_FAILURE,
4219 ssh_rportfwd_succfail, pf);
4228 static void ssh1_smsg_stdout_stderr_data(Ssh ssh, struct Packet *pktin)
4231 int stringlen, bufsize;
4233 ssh_pkt_getstring(pktin, &string, &stringlen);
4234 if (string == NULL) {
4235 bombout(("Incoming terminal data packet was badly formed"));
4239 bufsize = from_backend(ssh->frontend, pktin->type == SSH1_SMSG_STDERR_DATA,
4241 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
4242 ssh->v1_stdout_throttling = 1;
4243 ssh1_throttle(ssh, +1);
4247 static void ssh1_smsg_x11_open(Ssh ssh, struct Packet *pktin)
4249 /* Remote side is trying to open a channel to talk to our
4250 * X-Server. Give them back a local channel number. */
4251 struct ssh_channel *c;
4252 int remoteid = ssh_pkt_getuint32(pktin);
4254 logevent("Received X11 connect request");
4255 /* Refuse if X11 forwarding is disabled. */
4256 if (!ssh->X11_fwd_enabled) {
4257 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4258 PKT_INT, remoteid, PKT_END);
4259 logevent("Rejected X11 connect request");
4261 c = snew(struct ssh_channel);
4264 if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
4265 ssh->x11auth, NULL, -1, &ssh->cfg) != NULL) {
4266 logevent("Opening X11 forward connection failed");
4268 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4269 PKT_INT, remoteid, PKT_END);
4272 ("Opening X11 forward connection succeeded");
4273 c->remoteid = remoteid;
4274 c->halfopen = FALSE;
4275 c->localid = alloc_channel_id(ssh);
4277 c->v.v1.throttling = 0;
4278 c->type = CHAN_X11; /* identify channel type */
4279 add234(ssh->channels, c);
4280 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4281 PKT_INT, c->remoteid, PKT_INT,
4282 c->localid, PKT_END);
4283 logevent("Opened X11 forward channel");
4288 static void ssh1_smsg_agent_open(Ssh ssh, struct Packet *pktin)
4290 /* Remote side is trying to open a channel to talk to our
4291 * agent. Give them back a local channel number. */
4292 struct ssh_channel *c;
4293 int remoteid = ssh_pkt_getuint32(pktin);
4295 /* Refuse if agent forwarding is disabled. */
4296 if (!ssh->agentfwd_enabled) {
4297 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4298 PKT_INT, remoteid, PKT_END);
4300 c = snew(struct ssh_channel);
4302 c->remoteid = remoteid;
4303 c->halfopen = FALSE;
4304 c->localid = alloc_channel_id(ssh);
4306 c->v.v1.throttling = 0;
4307 c->type = CHAN_AGENT; /* identify channel type */
4308 c->u.a.lensofar = 0;
4309 add234(ssh->channels, c);
4310 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4311 PKT_INT, c->remoteid, PKT_INT, c->localid,
4316 static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin)
4318 /* Remote side is trying to open a channel to talk to a
4319 * forwarded port. Give them back a local channel number. */
4320 struct ssh_channel *c;
4321 struct ssh_rportfwd pf, *pfp;
4326 c = snew(struct ssh_channel);
4329 remoteid = ssh_pkt_getuint32(pktin);
4330 ssh_pkt_getstring(pktin, &host, &hostsize);
4331 port = ssh_pkt_getuint32(pktin);
4333 if (hostsize >= lenof(pf.dhost))
4334 hostsize = lenof(pf.dhost)-1;
4335 memcpy(pf.dhost, host, hostsize);
4336 pf.dhost[hostsize] = '\0';
4338 pfp = find234(ssh->rportfwds, &pf, NULL);
4341 logeventf(ssh, "Rejected remote port open request for %s:%d",
4343 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4344 PKT_INT, remoteid, PKT_END);
4346 logeventf(ssh, "Received remote port open request for %s:%d",
4348 e = pfd_newconnect(&c->u.pfd.s, pf.dhost, port,
4349 c, &ssh->cfg, pfp->pfrec->addressfamily);
4351 logeventf(ssh, "Port open failed: %s", e);
4353 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4354 PKT_INT, remoteid, PKT_END);
4356 c->remoteid = remoteid;
4357 c->halfopen = FALSE;
4358 c->localid = alloc_channel_id(ssh);
4360 c->v.v1.throttling = 0;
4361 c->type = CHAN_SOCKDATA; /* identify channel type */
4362 add234(ssh->channels, c);
4363 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4364 PKT_INT, c->remoteid, PKT_INT,
4365 c->localid, PKT_END);
4366 logevent("Forwarded port opened successfully");
4371 static void ssh1_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
4373 unsigned int remoteid = ssh_pkt_getuint32(pktin);
4374 unsigned int localid = ssh_pkt_getuint32(pktin);
4375 struct ssh_channel *c;
4377 c = find234(ssh->channels, &remoteid, ssh_channelfind);
4378 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
4379 c->remoteid = localid;
4380 c->halfopen = FALSE;
4381 c->type = CHAN_SOCKDATA;
4382 c->v.v1.throttling = 0;
4383 pfd_confirm(c->u.pfd.s);
4386 if (c && c->closes) {
4388 * We have a pending close on this channel,
4389 * which we decided on before the server acked
4390 * the channel open. So now we know the
4391 * remoteid, we can close it again.
4393 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE,
4394 PKT_INT, c->remoteid, PKT_END);
4398 static void ssh1_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
4400 unsigned int remoteid = ssh_pkt_getuint32(pktin);
4401 struct ssh_channel *c;
4403 c = find234(ssh->channels, &remoteid, ssh_channelfind);
4404 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
4405 logevent("Forwarded connection refused by server");
4406 pfd_close(c->u.pfd.s);
4407 del234(ssh->channels, c);
4412 static void ssh1_msg_channel_close(Ssh ssh, struct Packet *pktin)
4414 /* Remote side closes a channel. */
4415 unsigned i = ssh_pkt_getuint32(pktin);
4416 struct ssh_channel *c;
4417 c = find234(ssh->channels, &i, ssh_channelfind);
4418 if (c && !c->halfopen) {
4421 (pktin->type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
4423 if ((c->closes == 0) && (c->type == CHAN_X11)) {
4424 logevent("Forwarded X11 connection terminated");
4425 assert(c->u.x11.s != NULL);
4426 x11_close(c->u.x11.s);
4429 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
4430 logevent("Forwarded port closed");
4431 assert(c->u.pfd.s != NULL);
4432 pfd_close(c->u.pfd.s);
4436 c->closes |= (closetype << 2); /* seen this message */
4437 if (!(c->closes & closetype)) {
4438 send_packet(ssh, pktin->type, PKT_INT, c->remoteid,
4440 c->closes |= closetype; /* sent it too */
4443 if (c->closes == 15) {
4444 del234(ssh->channels, c);
4448 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
4449 pktin->type == SSH1_MSG_CHANNEL_CLOSE ? "" :
4450 "_CONFIRMATION", c ? "half-open" : "nonexistent",
4455 static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin)
4457 /* Data sent down one of our channels. */
4458 int i = ssh_pkt_getuint32(pktin);
4461 struct ssh_channel *c;
4463 ssh_pkt_getstring(pktin, &p, &len);
4465 c = find234(ssh->channels, &i, ssh_channelfind);
4470 bufsize = x11_send(c->u.x11.s, p, len);
4473 bufsize = pfd_send(c->u.pfd.s, p, len);
4476 /* Data for an agent message. Buffer it. */
4478 if (c->u.a.lensofar < 4) {
4479 unsigned int l = min(4 - c->u.a.lensofar, len);
4480 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
4484 c->u.a.lensofar += l;
4486 if (c->u.a.lensofar == 4) {
4488 4 + GET_32BIT(c->u.a.msglen);
4489 c->u.a.message = snewn(c->u.a.totallen,
4491 memcpy(c->u.a.message, c->u.a.msglen, 4);
4493 if (c->u.a.lensofar >= 4 && len > 0) {
4495 min(c->u.a.totallen - c->u.a.lensofar,
4497 memcpy(c->u.a.message + c->u.a.lensofar, p,
4501 c->u.a.lensofar += l;
4503 if (c->u.a.lensofar == c->u.a.totallen) {
4506 if (agent_query(c->u.a.message,
4509 ssh_agentf_callback, c))
4510 ssh_agentf_callback(c, reply, replylen);
4511 sfree(c->u.a.message);
4512 c->u.a.lensofar = 0;
4515 bufsize = 0; /* agent channels never back up */
4518 if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
4519 c->v.v1.throttling = 1;
4520 ssh1_throttle(ssh, +1);
4525 static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin)
4527 ssh->exitcode = ssh_pkt_getuint32(pktin);
4528 logeventf(ssh, "Server sent command exit status %d", ssh->exitcode);
4529 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
4531 * In case `helpful' firewalls or proxies tack
4532 * extra human-readable text on the end of the
4533 * session which we might mistake for another
4534 * encrypted packet, we close the session once
4535 * we've sent EXIT_CONFIRMATION.
4537 ssh->close_expected = TRUE;
4538 ssh_closing((Plug)ssh, NULL, 0, 0);
4541 /* Helper function to deal with sending tty modes for REQUEST_PTY */
4542 static void ssh1_send_ttymode(void *data, char *mode, char *val)
4544 struct Packet *pktout = (struct Packet *)data;
4546 unsigned int arg = 0;
4547 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
4548 if (i == lenof(ssh_ttymodes)) return;
4549 switch (ssh_ttymodes[i].type) {
4551 arg = ssh_tty_parse_specchar(val);
4554 arg = ssh_tty_parse_boolean(val);
4557 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
4558 ssh2_pkt_addbyte(pktout, arg);
4562 static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen,
4563 struct Packet *pktin)
4565 crBegin(ssh->do_ssh1_connection_crstate);
4567 ssh->packet_dispatch[SSH1_SMSG_STDOUT_DATA] =
4568 ssh->packet_dispatch[SSH1_SMSG_STDERR_DATA] =
4569 ssh1_smsg_stdout_stderr_data;
4571 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION] =
4572 ssh1_msg_channel_open_confirmation;
4573 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_FAILURE] =
4574 ssh1_msg_channel_open_failure;
4575 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE] =
4576 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION] =
4577 ssh1_msg_channel_close;
4578 ssh->packet_dispatch[SSH1_MSG_CHANNEL_DATA] = ssh1_msg_channel_data;
4579 ssh->packet_dispatch[SSH1_SMSG_EXIT_STATUS] = ssh1_smsg_exit_status;
4581 if (ssh->cfg.agentfwd && agent_exists()) {
4582 logevent("Requesting agent forwarding");
4583 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
4587 if (pktin->type != SSH1_SMSG_SUCCESS
4588 && pktin->type != SSH1_SMSG_FAILURE) {
4589 bombout(("Protocol confusion"));
4591 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4592 logevent("Agent forwarding refused");
4594 logevent("Agent forwarding enabled");
4595 ssh->agentfwd_enabled = TRUE;
4596 ssh->packet_dispatch[SSH1_SMSG_AGENT_OPEN] = ssh1_smsg_agent_open;
4600 if (ssh->cfg.x11_forward) {
4601 char proto[20], data[64];
4602 logevent("Requesting X11 forwarding");
4603 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
4604 data, sizeof(data), ssh->cfg.x11_auth);
4605 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
4606 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
4607 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
4608 PKT_STR, proto, PKT_STR, data,
4609 PKT_INT, x11_get_screen_number(ssh->cfg.x11_display),
4612 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
4613 PKT_STR, proto, PKT_STR, data, PKT_END);
4618 if (pktin->type != SSH1_SMSG_SUCCESS
4619 && pktin->type != SSH1_SMSG_FAILURE) {
4620 bombout(("Protocol confusion"));
4622 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4623 logevent("X11 forwarding refused");
4625 logevent("X11 forwarding enabled");
4626 ssh->X11_fwd_enabled = TRUE;
4627 ssh->packet_dispatch[SSH1_SMSG_X11_OPEN] = ssh1_smsg_x11_open;
4631 ssh_setup_portfwd(ssh, &ssh->cfg);
4632 ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] = ssh1_msg_port_open;
4634 if (!ssh->cfg.nopty) {
4636 /* Unpick the terminal-speed string. */
4637 /* XXX perhaps we should allow no speeds to be sent. */
4638 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
4639 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
4640 /* Send the pty request. */
4641 pkt = ssh1_pkt_init(SSH1_CMSG_REQUEST_PTY);
4642 ssh_pkt_addstring(pkt, ssh->cfg.termtype);
4643 ssh_pkt_adduint32(pkt, ssh->term_height);
4644 ssh_pkt_adduint32(pkt, ssh->term_width);
4645 ssh_pkt_adduint32(pkt, 0); /* width in pixels */
4646 ssh_pkt_adduint32(pkt, 0); /* height in pixels */
4647 parse_ttymodes(ssh, ssh->cfg.ttymodes,
4648 ssh1_send_ttymode, (void *)pkt);
4649 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_ISPEED);
4650 ssh_pkt_adduint32(pkt, ssh->ispeed);
4651 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_OSPEED);
4652 ssh_pkt_adduint32(pkt, ssh->ospeed);
4653 ssh_pkt_addbyte(pkt, SSH_TTY_OP_END);
4655 ssh->state = SSH_STATE_INTERMED;
4659 if (pktin->type != SSH1_SMSG_SUCCESS
4660 && pktin->type != SSH1_SMSG_FAILURE) {
4661 bombout(("Protocol confusion"));
4663 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4664 c_write_str(ssh, "Server refused to allocate pty\r\n");
4665 ssh->editing = ssh->echoing = 1;
4667 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
4668 ssh->ospeed, ssh->ispeed);
4670 ssh->editing = ssh->echoing = 1;
4673 if (ssh->cfg.compression) {
4674 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
4678 if (pktin->type != SSH1_SMSG_SUCCESS
4679 && pktin->type != SSH1_SMSG_FAILURE) {
4680 bombout(("Protocol confusion"));
4682 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4683 c_write_str(ssh, "Server refused to compress\r\n");
4685 logevent("Started compression");
4686 ssh->v1_compressing = TRUE;
4687 ssh->cs_comp_ctx = zlib_compress_init();
4688 logevent("Initialised zlib (RFC1950) compression");
4689 ssh->sc_comp_ctx = zlib_decompress_init();
4690 logevent("Initialised zlib (RFC1950) decompression");
4694 * Start the shell or command.
4696 * Special case: if the first-choice command is an SSH-2
4697 * subsystem (hence not usable here) and the second choice
4698 * exists, we fall straight back to that.
4701 char *cmd = ssh->cfg.remote_cmd_ptr;
4703 if (!cmd) cmd = ssh->cfg.remote_cmd;
4705 if (ssh->cfg.ssh_subsys && ssh->cfg.remote_cmd_ptr2) {
4706 cmd = ssh->cfg.remote_cmd_ptr2;
4707 ssh->fallback_cmd = TRUE;
4710 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
4712 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
4713 logevent("Started session");
4716 ssh->state = SSH_STATE_SESSION;
4717 if (ssh->size_needed)
4718 ssh_size(ssh, ssh->term_width, ssh->term_height);
4719 if (ssh->eof_needed)
4720 ssh_special(ssh, TS_EOF);
4723 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
4725 ssh->channels = newtree234(ssh_channelcmp);
4729 * By this point, most incoming packets are already being
4730 * handled by the dispatch table, and we need only pay
4731 * attention to the unusual ones.
4736 if (pktin->type == SSH1_SMSG_SUCCESS) {
4737 /* may be from EXEC_SHELL on some servers */
4738 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4739 /* may be from EXEC_SHELL on some servers
4740 * if no pty is available or in other odd cases. Ignore */
4742 bombout(("Strange packet received: type %d", pktin->type));
4747 int len = min(inlen, 512);
4748 send_packet(ssh, SSH1_CMSG_STDIN_DATA, PKTT_DATA,
4749 PKT_INT, len, PKT_DATA, in, len,
4750 PKTT_OTHER, PKT_END);
4761 * Handle the top-level SSH-2 protocol.
4763 static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin)
4768 ssh_pkt_getstring(pktin, &msg, &msglen);
4769 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
4772 static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin)
4774 /* log reason code in disconnect message */
4778 ssh_pkt_getstring(pktin, &msg, &msglen);
4779 bombout(("Server sent disconnect message:\n\"%.*s\"", msglen, msg));
4782 static void ssh_msg_ignore(Ssh ssh, struct Packet *pktin)
4784 /* Do nothing, because we're ignoring it! Duhh. */
4787 static void ssh1_protocol_setup(Ssh ssh)
4792 * Most messages are handled by the coroutines.
4794 for (i = 0; i < 256; i++)
4795 ssh->packet_dispatch[i] = NULL;
4798 * These special message types we install handlers for.
4800 ssh->packet_dispatch[SSH1_MSG_DISCONNECT] = ssh1_msg_disconnect;
4801 ssh->packet_dispatch[SSH1_MSG_IGNORE] = ssh_msg_ignore;
4802 ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug;
4805 static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
4806 struct Packet *pktin)
4808 unsigned char *in=(unsigned char*)vin;
4809 if (ssh->state == SSH_STATE_CLOSED)
4812 if (pktin && ssh->packet_dispatch[pktin->type]) {
4813 ssh->packet_dispatch[pktin->type](ssh, pktin);
4817 if (!ssh->protocol_initial_phase_done) {
4818 if (do_ssh1_login(ssh, in, inlen, pktin))
4819 ssh->protocol_initial_phase_done = TRUE;
4824 do_ssh1_connection(ssh, in, inlen, pktin);
4828 * Utility routine for decoding comma-separated strings in KEXINIT.
4830 static int in_commasep_string(char *needle, char *haystack, int haylen)
4833 if (!needle || !haystack) /* protect against null pointers */
4835 needlen = strlen(needle);
4838 * Is it at the start of the string?
4840 if (haylen >= needlen && /* haystack is long enough */
4841 !memcmp(needle, haystack, needlen) && /* initial match */
4842 (haylen == needlen || haystack[needlen] == ',')
4843 /* either , or EOS follows */
4847 * If not, search for the next comma and resume after that.
4848 * If no comma found, terminate.
4850 while (haylen > 0 && *haystack != ',')
4851 haylen--, haystack++;
4854 haylen--, haystack++; /* skip over comma itself */
4859 * Similar routine for checking whether we have the first string in a list.
4861 static int first_in_commasep_string(char *needle, char *haystack, int haylen)
4864 if (!needle || !haystack) /* protect against null pointers */
4866 needlen = strlen(needle);
4868 * Is it at the start of the string?
4870 if (haylen >= needlen && /* haystack is long enough */
4871 !memcmp(needle, haystack, needlen) && /* initial match */
4872 (haylen == needlen || haystack[needlen] == ',')
4873 /* either , or EOS follows */
4881 * SSH-2 key creation method.
4883 static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H,
4884 unsigned char *sessid, char chr,
4885 unsigned char *keyspace)
4888 /* First 20 bytes. */
4890 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
4892 SHA_Bytes(&s, H, 20);
4893 SHA_Bytes(&s, &chr, 1);
4894 SHA_Bytes(&s, sessid, 20);
4895 SHA_Final(&s, keyspace);
4896 /* Next 20 bytes. */
4898 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
4900 SHA_Bytes(&s, H, 20);
4901 SHA_Bytes(&s, keyspace, 20);
4902 SHA_Final(&s, keyspace + 20);
4906 * Handle the SSH-2 transport layer.
4908 static int do_ssh2_transport(Ssh ssh, void *vin, int inlen,
4909 struct Packet *pktin)
4911 unsigned char *in = (unsigned char *)vin;
4912 struct do_ssh2_transport_state {
4913 int nbits, pbits, warn_kex, warn_cscipher, warn_sccipher;
4914 Bignum p, g, e, f, K;
4915 int kex_init_value, kex_reply_value;
4916 const struct ssh_mac **maclist;
4918 const struct ssh2_cipher *cscipher_tobe;
4919 const struct ssh2_cipher *sccipher_tobe;
4920 const struct ssh_mac *csmac_tobe;
4921 const struct ssh_mac *scmac_tobe;
4922 const struct ssh_compress *cscomp_tobe;
4923 const struct ssh_compress *sccomp_tobe;
4924 char *hostkeydata, *sigdata, *keystr, *fingerprint;
4925 int hostkeylen, siglen;
4926 void *hkey; /* actual host key */
4927 unsigned char exchange_hash[20];
4928 int n_preferred_kex;
4929 const struct ssh_kex *preferred_kex[KEX_MAX];
4930 int n_preferred_ciphers;
4931 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
4932 const struct ssh_compress *preferred_comp;
4933 int got_session_id, activated_authconn;
4934 struct Packet *pktout;
4939 crState(do_ssh2_transport_state);
4941 crBegin(ssh->do_ssh2_transport_crstate);
4943 s->cscipher_tobe = s->sccipher_tobe = NULL;
4944 s->csmac_tobe = s->scmac_tobe = NULL;
4945 s->cscomp_tobe = s->sccomp_tobe = NULL;
4947 s->got_session_id = s->activated_authconn = FALSE;
4950 * Be prepared to work around the buggy MAC problem.
4952 if (ssh->remote_bugs & BUG_SSH2_HMAC)
4953 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
4955 s->maclist = macs, s->nmacs = lenof(macs);
4958 ssh->pkt_ctx &= ~SSH2_PKTCTX_KEX_MASK;
4960 int i, j, commalist_started;
4963 * Set up the preferred key exchange. (NULL => warn below here)
4965 s->n_preferred_kex = 0;
4966 for (i = 0; i < KEX_MAX; i++) {
4967 switch (ssh->cfg.ssh_kexlist[i]) {
4969 s->preferred_kex[s->n_preferred_kex++] =
4970 &ssh_diffiehellman_gex;
4973 s->preferred_kex[s->n_preferred_kex++] =
4974 &ssh_diffiehellman_group14;
4977 s->preferred_kex[s->n_preferred_kex++] =
4978 &ssh_diffiehellman_group1;
4981 /* Flag for later. Don't bother if it's the last in
4983 if (i < KEX_MAX - 1) {
4984 s->preferred_kex[s->n_preferred_kex++] = NULL;
4991 * Set up the preferred ciphers. (NULL => warn below here)
4993 s->n_preferred_ciphers = 0;
4994 for (i = 0; i < CIPHER_MAX; i++) {
4995 switch (ssh->cfg.ssh_cipherlist[i]) {
4996 case CIPHER_BLOWFISH:
4997 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
5000 if (ssh->cfg.ssh2_des_cbc) {
5001 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
5005 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
5008 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
5010 case CIPHER_ARCFOUR:
5011 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_arcfour;
5014 /* Flag for later. Don't bother if it's the last in
5016 if (i < CIPHER_MAX - 1) {
5017 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
5024 * Set up preferred compression.
5026 if (ssh->cfg.compression)
5027 s->preferred_comp = &ssh_zlib;
5029 s->preferred_comp = &ssh_comp_none;
5032 * Enable queueing of outgoing auth- or connection-layer
5033 * packets while we are in the middle of a key exchange.
5035 ssh->queueing = TRUE;
5038 * Flag that KEX is in progress.
5040 ssh->kex_in_progress = TRUE;
5043 * Construct and send our key exchange packet.
5045 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT);
5046 for (i = 0; i < 16; i++)
5047 ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte());
5048 /* List key exchange algorithms. */
5049 ssh2_pkt_addstring_start(s->pktout);
5050 commalist_started = 0;
5051 for (i = 0; i < s->n_preferred_kex; i++) {
5052 const struct ssh_kex *k = s->preferred_kex[i];
5053 if (!k) continue; /* warning flag */
5054 if (commalist_started)
5055 ssh2_pkt_addstring_str(s->pktout, ",");
5056 ssh2_pkt_addstring_str(s->pktout, s->preferred_kex[i]->name);
5057 commalist_started = 1;
5059 /* List server host key algorithms. */
5060 ssh2_pkt_addstring_start(s->pktout);
5061 for (i = 0; i < lenof(hostkey_algs); i++) {
5062 ssh2_pkt_addstring_str(s->pktout, hostkey_algs[i]->name);
5063 if (i < lenof(hostkey_algs) - 1)
5064 ssh2_pkt_addstring_str(s->pktout, ",");
5066 /* List client->server encryption algorithms. */
5067 ssh2_pkt_addstring_start(s->pktout);
5068 commalist_started = 0;
5069 for (i = 0; i < s->n_preferred_ciphers; i++) {
5070 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5071 if (!c) continue; /* warning flag */
5072 for (j = 0; j < c->nciphers; j++) {
5073 if (commalist_started)
5074 ssh2_pkt_addstring_str(s->pktout, ",");
5075 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
5076 commalist_started = 1;
5079 /* List server->client encryption algorithms. */
5080 ssh2_pkt_addstring_start(s->pktout);
5081 commalist_started = 0;
5082 for (i = 0; i < s->n_preferred_ciphers; i++) {
5083 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5084 if (!c) continue; /* warning flag */
5085 for (j = 0; j < c->nciphers; j++) {
5086 if (commalist_started)
5087 ssh2_pkt_addstring_str(s->pktout, ",");
5088 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
5089 commalist_started = 1;
5092 /* List client->server MAC algorithms. */
5093 ssh2_pkt_addstring_start(s->pktout);
5094 for (i = 0; i < s->nmacs; i++) {
5095 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
5096 if (i < s->nmacs - 1)
5097 ssh2_pkt_addstring_str(s->pktout, ",");
5099 /* List server->client MAC algorithms. */
5100 ssh2_pkt_addstring_start(s->pktout);
5101 for (i = 0; i < s->nmacs; i++) {
5102 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
5103 if (i < s->nmacs - 1)
5104 ssh2_pkt_addstring_str(s->pktout, ",");
5106 /* List client->server compression algorithms. */
5107 ssh2_pkt_addstring_start(s->pktout);
5108 assert(lenof(compressions) > 1);
5109 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
5110 for (i = 0; i < lenof(compressions); i++) {
5111 const struct ssh_compress *c = compressions[i];
5112 if (c != s->preferred_comp) {
5113 ssh2_pkt_addstring_str(s->pktout, ",");
5114 ssh2_pkt_addstring_str(s->pktout, c->name);
5117 /* List server->client compression algorithms. */
5118 ssh2_pkt_addstring_start(s->pktout);
5119 assert(lenof(compressions) > 1);
5120 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
5121 for (i = 0; i < lenof(compressions); i++) {
5122 const struct ssh_compress *c = compressions[i];
5123 if (c != s->preferred_comp) {
5124 ssh2_pkt_addstring_str(s->pktout, ",");
5125 ssh2_pkt_addstring_str(s->pktout, c->name);
5128 /* List client->server languages. Empty list. */
5129 ssh2_pkt_addstring_start(s->pktout);
5130 /* List server->client languages. Empty list. */
5131 ssh2_pkt_addstring_start(s->pktout);
5132 /* First KEX packet does _not_ follow, because we're not that brave. */
5133 ssh2_pkt_addbool(s->pktout, FALSE);
5135 ssh2_pkt_adduint32(s->pktout, 0);
5138 ssh->exhash = ssh->exhashbase;
5139 sha_string(&ssh->exhash, s->pktout->data + 5, s->pktout->length - 5);
5141 ssh2_pkt_send_noqueue(ssh, s->pktout);
5145 if (pktin->length > 5)
5146 sha_string(&ssh->exhash, pktin->data + 5, pktin->length - 5);
5149 * Now examine the other side's KEXINIT to see what we're up
5153 char *str, *preferred;
5156 if (pktin->type != SSH2_MSG_KEXINIT) {
5157 bombout(("expected key exchange packet from server"));
5161 ssh->hostkey = NULL;
5162 s->cscipher_tobe = NULL;
5163 s->sccipher_tobe = NULL;
5164 s->csmac_tobe = NULL;
5165 s->scmac_tobe = NULL;
5166 s->cscomp_tobe = NULL;
5167 s->sccomp_tobe = NULL;
5168 s->warn_kex = s->warn_cscipher = s->warn_sccipher = FALSE;
5170 pktin->savedpos += 16; /* skip garbage cookie */
5171 ssh_pkt_getstring(pktin, &str, &len); /* key exchange algorithms */
5174 for (i = 0; i < s->n_preferred_kex; i++) {
5175 const struct ssh_kex *k = s->preferred_kex[i];
5179 if (!preferred) preferred = k->name;
5180 if (in_commasep_string(k->name, str, len))
5187 bombout(("Couldn't agree a key exchange algorithm (available: %s)",
5188 str ? str : "(null)"));
5192 * Note that the server's guess is considered wrong if it doesn't match
5193 * the first algorithm in our list, even if it's still the algorithm
5196 s->guessok = first_in_commasep_string(preferred, str, len);
5197 ssh_pkt_getstring(pktin, &str, &len); /* host key algorithms */
5198 for (i = 0; i < lenof(hostkey_algs); i++) {
5199 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
5200 ssh->hostkey = hostkey_algs[i];
5204 s->guessok = s->guessok &&
5205 first_in_commasep_string(hostkey_algs[0]->name, str, len);
5206 ssh_pkt_getstring(pktin, &str, &len); /* client->server cipher */
5207 for (i = 0; i < s->n_preferred_ciphers; i++) {
5208 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5210 s->warn_cscipher = TRUE;
5212 for (j = 0; j < c->nciphers; j++) {
5213 if (in_commasep_string(c->list[j]->name, str, len)) {
5214 s->cscipher_tobe = c->list[j];
5219 if (s->cscipher_tobe)
5222 if (!s->cscipher_tobe) {
5223 bombout(("Couldn't agree a client-to-server cipher (available: %s)",
5224 str ? str : "(null)"));
5228 ssh_pkt_getstring(pktin, &str, &len); /* server->client cipher */
5229 for (i = 0; i < s->n_preferred_ciphers; i++) {
5230 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5232 s->warn_sccipher = TRUE;
5234 for (j = 0; j < c->nciphers; j++) {
5235 if (in_commasep_string(c->list[j]->name, str, len)) {
5236 s->sccipher_tobe = c->list[j];
5241 if (s->sccipher_tobe)
5244 if (!s->sccipher_tobe) {
5245 bombout(("Couldn't agree a server-to-client cipher (available: %s)",
5246 str ? str : "(null)"));
5250 ssh_pkt_getstring(pktin, &str, &len); /* client->server mac */
5251 for (i = 0; i < s->nmacs; i++) {
5252 if (in_commasep_string(s->maclist[i]->name, str, len)) {
5253 s->csmac_tobe = s->maclist[i];
5257 ssh_pkt_getstring(pktin, &str, &len); /* server->client mac */
5258 for (i = 0; i < s->nmacs; i++) {
5259 if (in_commasep_string(s->maclist[i]->name, str, len)) {
5260 s->scmac_tobe = s->maclist[i];
5264 ssh_pkt_getstring(pktin, &str, &len); /* client->server compression */
5265 for (i = 0; i < lenof(compressions) + 1; i++) {
5266 const struct ssh_compress *c =
5267 i == 0 ? s->preferred_comp : compressions[i - 1];
5268 if (in_commasep_string(c->name, str, len)) {
5273 ssh_pkt_getstring(pktin, &str, &len); /* server->client compression */
5274 for (i = 0; i < lenof(compressions) + 1; i++) {
5275 const struct ssh_compress *c =
5276 i == 0 ? s->preferred_comp : compressions[i - 1];
5277 if (in_commasep_string(c->name, str, len)) {
5282 ssh_pkt_getstring(pktin, &str, &len); /* client->server language */
5283 ssh_pkt_getstring(pktin, &str, &len); /* server->client language */
5284 s->ignorepkt = ssh2_pkt_getbool(pktin) && !s->guessok;
5287 ssh_set_frozen(ssh, 1);
5288 s->dlgret = askalg(ssh->frontend, "key-exchange algorithm",
5290 ssh_dialog_callback, ssh);
5291 if (s->dlgret < 0) {
5295 bombout(("Unexpected data from server while"
5296 " waiting for user response"));
5299 } while (pktin || inlen > 0);
5300 s->dlgret = ssh->user_response;
5302 ssh_set_frozen(ssh, 0);
5303 if (s->dlgret == 0) {
5304 ssh->close_expected = TRUE;
5305 ssh_closing((Plug)ssh, NULL, 0, 0);
5310 if (s->warn_cscipher) {
5311 ssh_set_frozen(ssh, 1);
5312 s->dlgret = askalg(ssh->frontend,
5313 "client-to-server cipher",
5314 s->cscipher_tobe->name,
5315 ssh_dialog_callback, ssh);
5316 if (s->dlgret < 0) {
5320 bombout(("Unexpected data from server while"
5321 " waiting for user response"));
5324 } while (pktin || inlen > 0);
5325 s->dlgret = ssh->user_response;
5327 ssh_set_frozen(ssh, 0);
5328 if (s->dlgret == 0) {
5329 ssh->close_expected = TRUE;
5330 ssh_closing((Plug)ssh, NULL, 0, 0);
5335 if (s->warn_sccipher) {
5336 ssh_set_frozen(ssh, 1);
5337 s->dlgret = askalg(ssh->frontend,
5338 "server-to-client cipher",
5339 s->sccipher_tobe->name,
5340 ssh_dialog_callback, ssh);
5341 if (s->dlgret < 0) {
5345 bombout(("Unexpected data from server while"
5346 " waiting for user response"));
5349 } while (pktin || inlen > 0);
5350 s->dlgret = ssh->user_response;
5352 ssh_set_frozen(ssh, 0);
5353 if (s->dlgret == 0) {
5354 ssh->close_expected = TRUE;
5355 ssh_closing((Plug)ssh, NULL, 0, 0);
5360 if (s->ignorepkt) /* first_kex_packet_follows */
5361 crWaitUntil(pktin); /* Ignore packet */
5365 * Work out the number of bits of key we will need from the key
5366 * exchange. We start with the maximum key length of either
5372 csbits = s->cscipher_tobe->keylen;
5373 scbits = s->sccipher_tobe->keylen;
5374 s->nbits = (csbits > scbits ? csbits : scbits);
5376 /* The keys only have 160-bit entropy, since they're based on
5377 * a SHA-1 hash. So cap the key size at 160 bits. */
5382 * If we're doing Diffie-Hellman group exchange, start by
5383 * requesting a group.
5385 if (!ssh->kex->pdata) {
5386 logevent("Doing Diffie-Hellman group exchange");
5387 ssh->pkt_ctx |= SSH2_PKTCTX_DHGEX;
5389 * Work out how big a DH group we will need to allow that
5392 s->pbits = 512 << ((s->nbits - 1) / 64);
5393 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
5394 ssh2_pkt_adduint32(s->pktout, s->pbits);
5395 ssh2_pkt_send_noqueue(ssh, s->pktout);
5398 if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) {
5399 bombout(("expected key exchange group packet from server"));
5402 s->p = ssh2_pkt_getmp(pktin);
5403 s->g = ssh2_pkt_getmp(pktin);
5404 if (!s->p || !s->g) {
5405 bombout(("unable to read mp-ints from incoming group packet"));
5408 ssh->kex_ctx = dh_setup_gex(s->p, s->g);
5409 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
5410 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
5412 ssh->pkt_ctx |= SSH2_PKTCTX_DHGROUP;
5413 ssh->kex_ctx = dh_setup_group(ssh->kex);
5414 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
5415 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
5416 logeventf(ssh, "Using Diffie-Hellman with standard group \"%s\"",
5417 ssh->kex->groupname);
5420 logevent("Doing Diffie-Hellman key exchange");
5422 * Now generate and send e for Diffie-Hellman.
5424 set_busy_status(ssh->frontend, BUSY_CPU); /* this can take a while */
5425 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
5426 s->pktout = ssh2_pkt_init(s->kex_init_value);
5427 ssh2_pkt_addmp(s->pktout, s->e);
5428 ssh2_pkt_send_noqueue(ssh, s->pktout);
5430 set_busy_status(ssh->frontend, BUSY_WAITING); /* wait for server */
5432 if (pktin->type != s->kex_reply_value) {
5433 bombout(("expected key exchange reply packet from server"));
5436 set_busy_status(ssh->frontend, BUSY_CPU); /* cogitate */
5437 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
5438 s->f = ssh2_pkt_getmp(pktin);
5440 bombout(("unable to parse key exchange reply packet"));
5443 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
5445 s->K = dh_find_K(ssh->kex_ctx, s->f);
5447 /* We assume everything from now on will be quick, and it might
5448 * involve user interaction. */
5449 set_busy_status(ssh->frontend, BUSY_NOT);
5451 sha_string(&ssh->exhash, s->hostkeydata, s->hostkeylen);
5452 if (ssh->kex == &ssh_diffiehellman_gex) {
5453 sha_uint32(&ssh->exhash, s->pbits);
5454 sha_mpint(&ssh->exhash, s->p);
5455 sha_mpint(&ssh->exhash, s->g);
5457 sha_mpint(&ssh->exhash, s->e);
5458 sha_mpint(&ssh->exhash, s->f);
5459 sha_mpint(&ssh->exhash, s->K);
5460 SHA_Final(&ssh->exhash, s->exchange_hash);
5462 dh_cleanup(ssh->kex_ctx);
5463 ssh->kex_ctx = NULL;
5466 debug(("Exchange hash is:\n"));
5467 dmemdump(s->exchange_hash, 20);
5470 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
5472 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
5473 (char *)s->exchange_hash, 20)) {
5474 bombout(("Server's host key did not match the signature supplied"));
5479 * Authenticate remote host: verify host key. (We've already
5480 * checked the signature of the exchange hash.)
5482 s->keystr = ssh->hostkey->fmtkey(s->hkey);
5483 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
5484 ssh_set_frozen(ssh, 1);
5485 s->dlgret = verify_ssh_host_key(ssh->frontend,
5486 ssh->savedhost, ssh->savedport,
5487 ssh->hostkey->keytype, s->keystr,
5489 ssh_dialog_callback, ssh);
5490 if (s->dlgret < 0) {
5494 bombout(("Unexpected data from server while waiting"
5495 " for user host key response"));
5498 } while (pktin || inlen > 0);
5499 s->dlgret = ssh->user_response;
5501 ssh_set_frozen(ssh, 0);
5502 if (s->dlgret == 0) {
5503 ssh->close_expected = TRUE;
5504 ssh_closing((Plug)ssh, NULL, 0, 0);
5507 if (!s->got_session_id) { /* don't bother logging this in rekeys */
5508 logevent("Host key fingerprint is:");
5509 logevent(s->fingerprint);
5511 sfree(s->fingerprint);
5513 ssh->hostkey->freekey(s->hkey);
5516 * The exchange hash from the very first key exchange is also
5517 * the session id, used in session key construction and
5520 if (!s->got_session_id) {
5521 memcpy(ssh->v2_session_id, s->exchange_hash,
5522 sizeof(s->exchange_hash));
5523 s->got_session_id = TRUE;
5527 * Send SSH2_MSG_NEWKEYS.
5529 s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS);
5530 ssh2_pkt_send_noqueue(ssh, s->pktout);
5531 ssh->outgoing_data_size = 0; /* start counting from here */
5534 * We've sent client NEWKEYS, so create and initialise
5535 * client-to-server session keys.
5537 if (ssh->cs_cipher_ctx)
5538 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
5539 ssh->cscipher = s->cscipher_tobe;
5540 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
5542 if (ssh->cs_mac_ctx)
5543 ssh->csmac->free_context(ssh->cs_mac_ctx);
5544 ssh->csmac = s->csmac_tobe;
5545 ssh->cs_mac_ctx = ssh->csmac->make_context();
5547 if (ssh->cs_comp_ctx)
5548 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
5549 ssh->cscomp = s->cscomp_tobe;
5550 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
5553 * Set IVs on client-to-server keys. Here we use the exchange
5554 * hash from the _first_ key exchange.
5557 unsigned char keyspace[40];
5558 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'C',keyspace);
5559 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
5560 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'A',keyspace);
5561 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
5562 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'E',keyspace);
5563 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
5566 logeventf(ssh, "Initialised %.200s client->server encryption",
5567 ssh->cscipher->text_name);
5568 logeventf(ssh, "Initialised %.200s client->server MAC algorithm",
5569 ssh->csmac->text_name);
5570 if (ssh->cscomp->text_name)
5571 logeventf(ssh, "Initialised %s compression",
5572 ssh->cscomp->text_name);
5575 * Now our end of the key exchange is complete, we can send all
5576 * our queued higher-layer packets.
5578 ssh->queueing = FALSE;
5579 ssh2_pkt_queuesend(ssh);
5582 * Expect SSH2_MSG_NEWKEYS from server.
5585 if (pktin->type != SSH2_MSG_NEWKEYS) {
5586 bombout(("expected new-keys packet from server"));
5589 ssh->incoming_data_size = 0; /* start counting from here */
5592 * We've seen server NEWKEYS, so create and initialise
5593 * server-to-client session keys.
5595 if (ssh->sc_cipher_ctx)
5596 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
5597 ssh->sccipher = s->sccipher_tobe;
5598 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
5600 if (ssh->sc_mac_ctx)
5601 ssh->scmac->free_context(ssh->sc_mac_ctx);
5602 ssh->scmac = s->scmac_tobe;
5603 ssh->sc_mac_ctx = ssh->scmac->make_context();
5605 if (ssh->sc_comp_ctx)
5606 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
5607 ssh->sccomp = s->sccomp_tobe;
5608 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
5611 * Set IVs on server-to-client keys. Here we use the exchange
5612 * hash from the _first_ key exchange.
5615 unsigned char keyspace[40];
5616 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'D',keyspace);
5617 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
5618 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'B',keyspace);
5619 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
5620 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'F',keyspace);
5621 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
5623 logeventf(ssh, "Initialised %.200s server->client encryption",
5624 ssh->sccipher->text_name);
5625 logeventf(ssh, "Initialised %.200s server->client MAC algorithm",
5626 ssh->scmac->text_name);
5627 if (ssh->sccomp->text_name)
5628 logeventf(ssh, "Initialised %s decompression",
5629 ssh->sccomp->text_name);
5632 * Free key exchange data.
5636 if (ssh->kex == &ssh_diffiehellman_gex) {
5642 * Key exchange is over. Loop straight back round if we have a
5643 * deferred rekey reason.
5645 if (ssh->deferred_rekey_reason) {
5646 logevent(ssh->deferred_rekey_reason);
5648 ssh->deferred_rekey_reason = NULL;
5649 goto begin_key_exchange;
5653 * Otherwise, schedule a timer for our next rekey.
5655 ssh->kex_in_progress = FALSE;
5656 ssh->last_rekey = GETTICKCOUNT();
5657 if (ssh->cfg.ssh_rekey_time != 0)
5658 ssh->next_rekey = schedule_timer(ssh->cfg.ssh_rekey_time*60*TICKSPERSEC,
5662 * If this is the first key exchange phase, we must pass the
5663 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
5664 * wants to see it but because it will need time to initialise
5665 * itself before it sees an actual packet. In subsequent key
5666 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
5667 * it would only confuse the layer above.
5669 if (s->activated_authconn) {
5672 s->activated_authconn = TRUE;
5675 * Now we're encrypting. Begin returning 1 to the protocol main
5676 * function so that other things can run on top of the
5677 * transport. If we ever see a KEXINIT, we must go back to the
5680 * We _also_ go back to the start if we see pktin==NULL and
5681 * inlen==-1, because this is a special signal meaning
5682 * `initiate client-driven rekey', and `in' contains a message
5683 * giving the reason for the rekey.
5685 while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) ||
5686 (!pktin && inlen == -1))) {
5691 logevent("Server initiated key re-exchange");
5694 * Special case: if the server bug is set that doesn't
5695 * allow rekeying, we give a different log message and
5696 * continue waiting. (If such a server _initiates_ a rekey,
5697 * we process it anyway!)
5699 if ((ssh->remote_bugs & BUG_SSH2_REKEY)) {
5700 logeventf(ssh, "Server bug prevents key re-exchange (%s)",
5702 /* Reset the counters, so that at least this message doesn't
5703 * hit the event log _too_ often. */
5704 ssh->outgoing_data_size = 0;
5705 ssh->incoming_data_size = 0;
5706 if (ssh->cfg.ssh_rekey_time != 0) {
5708 schedule_timer(ssh->cfg.ssh_rekey_time*60*TICKSPERSEC,
5711 goto wait_for_rekey; /* this is utterly horrid */
5713 logeventf(ssh, "Initiating key re-exchange (%s)", (char *)in);
5716 goto begin_key_exchange;
5722 * Add data to an SSH-2 channel output buffer.
5724 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
5727 bufchain_add(&c->v.v2.outbuffer, buf, len);
5731 * Attempt to send data on an SSH-2 channel.
5733 static int ssh2_try_send(struct ssh_channel *c)
5736 struct Packet *pktout;
5738 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
5741 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
5742 if ((unsigned)len > c->v.v2.remwindow)
5743 len = c->v.v2.remwindow;
5744 if ((unsigned)len > c->v.v2.remmaxpkt)
5745 len = c->v.v2.remmaxpkt;
5746 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
5747 ssh2_pkt_adduint32(pktout, c->remoteid);
5748 dont_log_data(ssh, pktout, PKTLOG_OMIT);
5749 ssh2_pkt_addstring_start(pktout);
5750 ssh2_pkt_addstring_data(pktout, data, len);
5751 end_log_omission(ssh, pktout);
5752 ssh2_pkt_send(ssh, pktout);
5753 bufchain_consume(&c->v.v2.outbuffer, len);
5754 c->v.v2.remwindow -= len;
5758 * After having sent as much data as we can, return the amount
5761 return bufchain_size(&c->v.v2.outbuffer);
5764 static void ssh2_try_send_and_unthrottle(struct ssh_channel *c)
5768 return; /* don't send on closing channels */
5769 bufsize = ssh2_try_send(c);
5772 case CHAN_MAINSESSION:
5773 /* stdin need not receive an unthrottle
5774 * notification since it will be polled */
5777 x11_unthrottle(c->u.x11.s);
5780 /* agent sockets are request/response and need no
5781 * buffer management */
5784 pfd_unthrottle(c->u.pfd.s);
5791 * Potentially enlarge the window on an SSH-2 channel.
5793 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
5798 * Never send WINDOW_ADJUST for a channel that the remote side
5799 * already thinks it's closed; there's no point, since it won't
5800 * be sending any more data anyway.
5806 * Only send a WINDOW_ADJUST if there's significantly more window
5807 * available than the other end thinks there is. This saves us
5808 * sending a WINDOW_ADJUST for every character in a shell session.
5810 * "Significant" is arbitrarily defined as half the window size.
5812 if (newwin > c->v.v2.locwindow * 2) {
5813 struct Packet *pktout;
5815 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5816 ssh2_pkt_adduint32(pktout, c->remoteid);
5817 ssh2_pkt_adduint32(pktout, newwin - c->v.v2.locwindow);
5818 ssh2_pkt_send(ssh, pktout);
5819 c->v.v2.locwindow = newwin;
5823 static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin)
5825 unsigned i = ssh_pkt_getuint32(pktin);
5826 struct ssh_channel *c;
5827 c = find234(ssh->channels, &i, ssh_channelfind);
5828 if (c && !c->closes) {
5829 c->v.v2.remwindow += ssh_pkt_getuint32(pktin);
5830 ssh2_try_send_and_unthrottle(c);
5834 static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin)
5838 unsigned i = ssh_pkt_getuint32(pktin);
5839 struct ssh_channel *c;
5840 c = find234(ssh->channels, &i, ssh_channelfind);
5842 return; /* nonexistent channel */
5843 if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
5844 ssh_pkt_getuint32(pktin) != SSH2_EXTENDED_DATA_STDERR)
5845 return; /* extended but not stderr */
5846 ssh_pkt_getstring(pktin, &data, &length);
5849 c->v.v2.locwindow -= length;
5851 case CHAN_MAINSESSION:
5853 from_backend(ssh->frontend, pktin->type ==
5854 SSH2_MSG_CHANNEL_EXTENDED_DATA,
5858 bufsize = x11_send(c->u.x11.s, data, length);
5861 bufsize = pfd_send(c->u.pfd.s, data, length);
5864 while (length > 0) {
5865 if (c->u.a.lensofar < 4) {
5866 unsigned int l = min(4 - c->u.a.lensofar, length);
5867 memcpy(c->u.a.msglen + c->u.a.lensofar,
5871 c->u.a.lensofar += l;
5873 if (c->u.a.lensofar == 4) {
5875 4 + GET_32BIT(c->u.a.msglen);
5876 c->u.a.message = snewn(c->u.a.totallen,
5878 memcpy(c->u.a.message, c->u.a.msglen, 4);
5880 if (c->u.a.lensofar >= 4 && length > 0) {
5882 min(c->u.a.totallen - c->u.a.lensofar,
5884 memcpy(c->u.a.message + c->u.a.lensofar,
5888 c->u.a.lensofar += l;
5890 if (c->u.a.lensofar == c->u.a.totallen) {
5893 if (agent_query(c->u.a.message,
5896 ssh_agentf_callback, c))
5897 ssh_agentf_callback(c, reply, replylen);
5898 sfree(c->u.a.message);
5899 c->u.a.lensofar = 0;
5906 * If we are not buffering too much data,
5907 * enlarge the window again at the remote side.
5909 if (bufsize < OUR_V2_WINSIZE)
5910 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
5914 static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin)
5916 unsigned i = ssh_pkt_getuint32(pktin);
5917 struct ssh_channel *c;
5919 c = find234(ssh->channels, &i, ssh_channelfind);
5921 return; /* nonexistent channel */
5923 if (c->type == CHAN_X11) {
5925 * Remote EOF on an X11 channel means we should
5926 * wrap up and close the channel ourselves.
5928 x11_close(c->u.x11.s);
5930 } else if (c->type == CHAN_AGENT) {
5932 } else if (c->type == CHAN_SOCKDATA) {
5933 pfd_close(c->u.pfd.s);
5938 static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin)
5940 unsigned i = ssh_pkt_getuint32(pktin);
5941 struct ssh_channel *c;
5942 struct Packet *pktout;
5944 c = find234(ssh->channels, &i, ssh_channelfind);
5945 if (!c || c->halfopen) {
5946 bombout(("Received CHANNEL_CLOSE for %s channel %d\n",
5947 c ? "half-open" : "nonexistent", i));
5950 /* Do pre-close processing on the channel. */
5952 case CHAN_MAINSESSION:
5953 ssh->mainchan = NULL;
5954 update_specials_menu(ssh->frontend);
5957 if (c->u.x11.s != NULL)
5958 x11_close(c->u.x11.s);
5965 if (c->u.pfd.s != NULL)
5966 pfd_close(c->u.pfd.s);
5970 if (c->closes == 0) {
5971 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
5972 ssh2_pkt_adduint32(pktout, c->remoteid);
5973 ssh2_pkt_send(ssh, pktout);
5975 del234(ssh->channels, c);
5976 bufchain_clear(&c->v.v2.outbuffer);
5980 * See if that was the last channel left open.
5981 * (This is only our termination condition if we're
5982 * not running in -N mode.)
5984 if (!ssh->cfg.ssh_no_shell && count234(ssh->channels) == 0) {
5985 logevent("All channels closed. Disconnecting");
5988 * We used to send SSH_MSG_DISCONNECT here,
5989 * because I'd believed that _every_ conforming
5990 * SSH-2 connection had to end with a disconnect
5991 * being sent by at least one side; apparently
5992 * I was wrong and it's perfectly OK to
5993 * unceremoniously slam the connection shut
5994 * when you're done, and indeed OpenSSH feels
5995 * this is more polite than sending a
5996 * DISCONNECT. So now we don't.
5998 s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
5999 ssh2_pkt_adduint32(s->pktout, SSH2_DISCONNECT_BY_APPLICATION);
6000 ssh2_pkt_addstring(s->pktout, "All open channels closed");
6001 ssh2_pkt_addstring(s->pktout, "en"); /* language tag */
6002 ssh2_pkt_send_noqueue(ssh, s->pktout);
6004 ssh->close_expected = TRUE;
6005 ssh_closing((Plug)ssh, NULL, 0, 0);
6009 static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
6011 unsigned i = ssh_pkt_getuint32(pktin);
6012 struct ssh_channel *c;
6013 struct Packet *pktout;
6015 c = find234(ssh->channels, &i, ssh_channelfind);
6017 return; /* nonexistent channel */
6018 if (c->type != CHAN_SOCKDATA_DORMANT)
6019 return; /* dunno why they're confirming this */
6020 c->remoteid = ssh_pkt_getuint32(pktin);
6021 c->halfopen = FALSE;
6022 c->type = CHAN_SOCKDATA;
6023 c->v.v2.remwindow = ssh_pkt_getuint32(pktin);
6024 c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
6026 pfd_confirm(c->u.pfd.s);
6029 * We have a pending close on this channel,
6030 * which we decided on before the server acked
6031 * the channel open. So now we know the
6032 * remoteid, we can close it again.
6034 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
6035 ssh2_pkt_adduint32(pktout, c->remoteid);
6036 ssh2_pkt_send(ssh, pktout);
6040 static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
6042 static const char *const reasons[] = {
6043 "<unknown reason code>",
6044 "Administratively prohibited",
6046 "Unknown channel type",
6047 "Resource shortage",
6049 unsigned i = ssh_pkt_getuint32(pktin);
6050 unsigned reason_code;
6051 char *reason_string;
6053 struct ssh_channel *c;
6054 c = find234(ssh->channels, &i, ssh_channelfind);
6056 return; /* nonexistent channel */
6057 if (c->type != CHAN_SOCKDATA_DORMANT)
6058 return; /* dunno why they're failing this */
6060 reason_code = ssh_pkt_getuint32(pktin);
6061 if (reason_code >= lenof(reasons))
6062 reason_code = 0; /* ensure reasons[reason_code] in range */
6063 ssh_pkt_getstring(pktin, &reason_string, &reason_length);
6064 logeventf(ssh, "Forwarded connection refused by server: %s [%.*s]",
6065 reasons[reason_code], reason_length, reason_string);
6067 pfd_close(c->u.pfd.s);
6069 del234(ssh->channels, c);
6073 static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin)
6077 int typelen, want_reply;
6078 int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */
6079 struct ssh_channel *c;
6080 struct Packet *pktout;
6082 localid = ssh_pkt_getuint32(pktin);
6083 ssh_pkt_getstring(pktin, &type, &typelen);
6084 want_reply = ssh2_pkt_getbool(pktin);
6087 * First, check that the channel exists. Otherwise,
6088 * we can instantly disconnect with a rude message.
6090 c = find234(ssh->channels, &localid, ssh_channelfind);
6093 sprintf(buf, "Received channel request for nonexistent"
6094 " channel %d", localid);
6096 pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
6097 ssh2_pkt_adduint32(pktout, SSH2_DISCONNECT_BY_APPLICATION);
6098 ssh2_pkt_addstring(pktout, buf);
6099 ssh2_pkt_addstring(pktout, "en"); /* language tag */
6100 ssh2_pkt_send_noqueue(ssh, pktout);
6101 connection_fatal(ssh->frontend, "%s", buf);
6102 ssh->close_expected = TRUE;
6103 ssh_closing((Plug)ssh, NULL, 0, 0);
6108 * Having got the channel number, we now look at
6109 * the request type string to see if it's something
6112 if (c == ssh->mainchan) {
6114 * We recognise "exit-status" and "exit-signal" on
6115 * the primary channel.
6117 if (typelen == 11 &&
6118 !memcmp(type, "exit-status", 11)) {
6120 ssh->exitcode = ssh_pkt_getuint32(pktin);
6121 logeventf(ssh, "Server sent command exit status %d",
6123 reply = SSH2_MSG_CHANNEL_SUCCESS;
6125 } else if (typelen == 11 &&
6126 !memcmp(type, "exit-signal", 11)) {
6128 int is_plausible = TRUE, is_int = FALSE;
6129 char *fmt_sig = "", *fmt_msg = "";
6131 int msglen = 0, core = FALSE;
6132 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
6133 * provide an `int' for the signal, despite its
6134 * having been a `string' in the drafts since at
6135 * least 2001. (Fixed in session.c 1.147.) Try to
6136 * infer which we can safely parse it as. */
6138 unsigned char *p = pktin->body +
6140 long len = pktin->length - pktin->savedpos;
6141 unsigned long num = GET_32BIT(p); /* what is it? */
6142 /* If it's 0, it hardly matters; assume string */
6146 int maybe_int = FALSE, maybe_str = FALSE;
6147 #define CHECK_HYPOTHESIS(offset, result) \
6150 if (q >= 0 && q+4 <= len) { \
6151 q = q + 4 + GET_32BIT(p+q); \
6152 if (q >= 0 && q+4 <= len && \
6153 ((q = q + 4 + GET_32BIT(p+q))!= 0) && q == len) \
6157 CHECK_HYPOTHESIS(4+1, maybe_int);
6158 CHECK_HYPOTHESIS(4+num+1, maybe_str);
6159 #undef CHECK_HYPOTHESIS
6160 if (maybe_int && !maybe_str)
6162 else if (!maybe_int && maybe_str)
6165 /* Crikey. Either or neither. Panic. */
6166 is_plausible = FALSE;
6171 /* Old non-standard OpenSSH. */
6172 int signum = ssh_pkt_getuint32(pktin);
6173 fmt_sig = dupprintf(" %d", signum);
6175 /* As per the drafts. */
6178 ssh_pkt_getstring(pktin, &sig, &siglen);
6179 /* Signal name isn't supposed to be blank, but
6180 * let's cope gracefully if it is. */
6182 fmt_sig = dupprintf(" \"%.*s\"",
6186 core = ssh2_pkt_getbool(pktin);
6187 ssh_pkt_getstring(pktin, &msg, &msglen);
6189 fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg);
6191 /* ignore lang tag */
6192 } /* else don't attempt to parse */
6193 logeventf(ssh, "Server exited on signal%s%s%s",
6194 fmt_sig, core ? " (core dumped)" : "",
6196 if (*fmt_sig) sfree(fmt_sig);
6197 if (*fmt_msg) sfree(fmt_msg);
6198 reply = SSH2_MSG_CHANNEL_SUCCESS;
6203 * This is a channel request we don't know
6204 * about, so we now either ignore the request
6205 * or respond with CHANNEL_FAILURE, depending
6208 reply = SSH2_MSG_CHANNEL_FAILURE;
6211 pktout = ssh2_pkt_init(reply);
6212 ssh2_pkt_adduint32(pktout, c->remoteid);
6213 ssh2_pkt_send(ssh, pktout);
6217 static void ssh2_msg_global_request(Ssh ssh, struct Packet *pktin)
6220 int typelen, want_reply;
6221 struct Packet *pktout;
6223 ssh_pkt_getstring(pktin, &type, &typelen);
6224 want_reply = ssh2_pkt_getbool(pktin);
6227 * We currently don't support any global requests
6228 * at all, so we either ignore the request or
6229 * respond with REQUEST_FAILURE, depending on
6233 pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
6234 ssh2_pkt_send(ssh, pktout);
6238 static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin)
6246 struct ssh_channel *c;
6247 unsigned remid, winsize, pktsize;
6248 struct Packet *pktout;
6250 ssh_pkt_getstring(pktin, &type, &typelen);
6251 c = snew(struct ssh_channel);
6254 remid = ssh_pkt_getuint32(pktin);
6255 winsize = ssh_pkt_getuint32(pktin);
6256 pktsize = ssh_pkt_getuint32(pktin);
6258 if (typelen == 3 && !memcmp(type, "x11", 3)) {
6261 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
6262 addrstr = snewn(peeraddrlen+1, char);
6263 memcpy(addrstr, peeraddr, peeraddrlen);
6264 addrstr[peeraddrlen] = '\0';
6265 peerport = ssh_pkt_getuint32(pktin);
6267 logeventf(ssh, "Received X11 connect request from %s:%d",
6270 if (!ssh->X11_fwd_enabled)
6271 error = "X11 forwarding is not enabled";
6272 else if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
6273 ssh->x11auth, addrstr, peerport,
6274 &ssh->cfg) != NULL) {
6275 error = "Unable to open an X11 connection";
6277 logevent("Opening X11 forward connection succeeded");
6282 } else if (typelen == 15 &&
6283 !memcmp(type, "forwarded-tcpip", 15)) {
6284 struct ssh_rportfwd pf, *realpf;
6287 ssh_pkt_getstring(pktin, &dummy, &dummylen);/* skip address */
6288 pf.sport = ssh_pkt_getuint32(pktin);
6289 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
6290 peerport = ssh_pkt_getuint32(pktin);
6291 realpf = find234(ssh->rportfwds, &pf, NULL);
6292 logeventf(ssh, "Received remote port %d open request "
6293 "from %s:%d", pf.sport, peeraddr, peerport);
6294 if (realpf == NULL) {
6295 error = "Remote port is not recognised";
6297 const char *e = pfd_newconnect(&c->u.pfd.s,
6301 realpf->pfrec->addressfamily);
6302 logeventf(ssh, "Attempting to forward remote port to "
6303 "%s:%d", realpf->dhost, realpf->dport);
6305 logeventf(ssh, "Port open failed: %s", e);
6306 error = "Port open failed";
6308 logevent("Forwarded port opened successfully");
6309 c->type = CHAN_SOCKDATA;
6312 } else if (typelen == 22 &&
6313 !memcmp(type, "auth-agent@openssh.com", 3)) {
6314 if (!ssh->agentfwd_enabled)
6315 error = "Agent forwarding is not enabled";
6317 c->type = CHAN_AGENT; /* identify channel type */
6318 c->u.a.lensofar = 0;
6321 error = "Unsupported channel type requested";
6324 c->remoteid = remid;
6325 c->halfopen = FALSE;
6327 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
6328 ssh2_pkt_adduint32(pktout, c->remoteid);
6329 ssh2_pkt_adduint32(pktout, SSH2_OPEN_CONNECT_FAILED);
6330 ssh2_pkt_addstring(pktout, error);
6331 ssh2_pkt_addstring(pktout, "en"); /* language tag */
6332 ssh2_pkt_send(ssh, pktout);
6333 logeventf(ssh, "Rejected channel open: %s", error);
6336 c->localid = alloc_channel_id(ssh);
6338 c->v.v2.locwindow = OUR_V2_WINSIZE;
6339 c->v.v2.remwindow = winsize;
6340 c->v.v2.remmaxpkt = pktsize;
6341 bufchain_init(&c->v.v2.outbuffer);
6342 add234(ssh->channels, c);
6343 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
6344 ssh2_pkt_adduint32(pktout, c->remoteid);
6345 ssh2_pkt_adduint32(pktout, c->localid);
6346 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);
6347 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
6348 ssh2_pkt_send(ssh, pktout);
6352 /* Helper function to deal with sending tty modes for "pty-req" */
6353 static void ssh2_send_ttymode(void *data, char *mode, char *val)
6355 struct Packet *pktout = (struct Packet *)data;
6357 unsigned int arg = 0;
6358 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
6359 if (i == lenof(ssh_ttymodes)) return;
6360 switch (ssh_ttymodes[i].type) {
6362 arg = ssh_tty_parse_specchar(val);
6365 arg = ssh_tty_parse_boolean(val);
6368 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
6369 ssh2_pkt_adduint32(pktout, arg);
6373 * Handle the SSH-2 userauth and connection layers.
6375 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
6376 struct Packet *pktin)
6378 struct do_ssh2_authconn_state {
6380 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
6382 AUTH_KEYBOARD_INTERACTIVE
6386 AUTH_TYPE_PUBLICKEY,
6387 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
6388 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
6390 AUTH_TYPE_KEYBOARD_INTERACTIVE,
6391 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
6393 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
6394 int tried_pubkey_config, tried_agent;
6395 int kbd_inter_running, kbd_inter_refused;
6397 int num_prompts, curr_prompt, echo;
6402 void *publickey_blob;
6403 int publickey_bloblen;
6404 unsigned char request[5], *response, *p;
6408 char *pkblob, *alg, *commentp;
6409 int pklen, alglen, commentlen;
6410 int siglen, retlen, len;
6411 char *q, *agentreq, *ret;
6413 int num_env, env_left, env_ok;
6414 struct Packet *pktout;
6416 crState(do_ssh2_authconn_state);
6418 crBegin(ssh->do_ssh2_authconn_crstate);
6421 * Request userauth protocol, and await a response to it.
6423 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
6424 ssh2_pkt_addstring(s->pktout, "ssh-userauth");
6425 ssh2_pkt_send(ssh, s->pktout);
6426 crWaitUntilV(pktin);
6427 if (pktin->type != SSH2_MSG_SERVICE_ACCEPT) {
6428 bombout(("Server refused user authentication protocol"));
6433 * We repeat this whole loop, including the username prompt,
6434 * until we manage a successful authentication. If the user
6435 * types the wrong _password_, they can be sent back to the
6436 * beginning to try another username, if this is configured on.
6437 * (If they specify a username in the config, they are never
6438 * asked, even if they do give a wrong password.)
6440 * I think this best serves the needs of
6442 * - the people who have no configuration, no keys, and just
6443 * want to try repeated (username,password) pairs until they
6444 * type both correctly
6446 * - people who have keys and configuration but occasionally
6447 * need to fall back to passwords
6449 * - people with a key held in Pageant, who might not have
6450 * logged in to a particular machine before; so they want to
6451 * type a username, and then _either_ their key will be
6452 * accepted, _or_ they will type a password. If they mistype
6453 * the username they will want to be able to get back and
6456 s->username[0] = '\0';
6457 s->got_username = FALSE;
6462 if (s->got_username && !ssh->cfg.change_username) {
6464 * We got a username last time round this loop, and
6465 * with change_username turned off we don't try to get
6468 } else if (!*ssh->cfg.username) {
6469 if (ssh_get_line && !ssh_getline_pw_only) {
6470 if (!ssh_get_line("login as: ",
6471 s->username, sizeof(s->username), FALSE)) {
6473 * get_line failed to get a username.
6476 logevent("No username provided. Abandoning session.");
6477 ssh->close_expected = TRUE;
6478 ssh_closing((Plug)ssh, NULL, 0, 0);
6482 int ret; /* need not be saved across crReturn */
6483 c_write_str(ssh, "login as: ");
6485 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
6487 crWaitUntilV(!pktin);
6488 ret = process_userpass_input(ssh, in, inlen);
6492 c_write_str(ssh, "\r\n");
6494 s->username[strcspn(s->username, "\n\r")] = '\0';
6497 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
6498 s->username[sizeof(s->username)-1] = '\0';
6499 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
6500 stuff = dupprintf("Using username \"%s\".\r\n", s->username);
6501 c_write_str(ssh, stuff);
6505 s->got_username = TRUE;
6508 * Send an authentication request using method "none": (a)
6509 * just in case it succeeds, and (b) so that we know what
6510 * authentication methods we can usefully try next.
6512 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6514 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6515 ssh2_pkt_addstring(s->pktout, s->username);
6516 ssh2_pkt_addstring(s->pktout, "ssh-connection");/* service requested */
6517 ssh2_pkt_addstring(s->pktout, "none"); /* method */
6518 ssh2_pkt_send(ssh, s->pktout);
6519 s->type = AUTH_TYPE_NONE;
6521 s->we_are_in = FALSE;
6523 s->tried_pubkey_config = FALSE;
6524 s->tried_agent = FALSE;
6525 s->kbd_inter_running = FALSE;
6526 s->kbd_inter_refused = FALSE;
6527 /* Load the pub half of ssh->cfg.keyfile so we notice if it's in Pageant */
6528 if (!filename_is_null(ssh->cfg.keyfile)) {
6530 logeventf(ssh, "Reading private key file \"%.150s\"",
6531 filename_to_str(&ssh->cfg.keyfile));
6532 keytype = key_type(&ssh->cfg.keyfile);
6533 if (keytype == SSH_KEYTYPE_SSH2) {
6535 ssh2_userkey_loadpub(&ssh->cfg.keyfile, NULL,
6536 &s->publickey_bloblen, NULL);
6539 logeventf(ssh, "Unable to use this key file (%s)",
6540 key_type_to_str(keytype));
6541 msgbuf = dupprintf("Unable to use key file \"%.150s\""
6543 filename_to_str(&ssh->cfg.keyfile),
6544 key_type_to_str(keytype));
6545 c_write_str(ssh, msgbuf);
6547 s->publickey_blob = NULL;
6550 s->publickey_blob = NULL;
6554 * Wait for the result of the last authentication request.
6557 crWaitUntilV(pktin);
6558 while (pktin->type == SSH2_MSG_USERAUTH_BANNER) {
6562 * Don't show the banner if we're operating in
6563 * non-verbose non-interactive mode. (It's probably
6564 * a script, which means nobody will read the
6565 * banner _anyway_, and moreover the printing of
6566 * the banner will screw up processing on the
6567 * output of (say) plink.)
6569 if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
6570 ssh_pkt_getstring(pktin, &banner, &size);
6572 c_write_untrusted(ssh, banner, size);
6574 crWaitUntilV(pktin);
6576 if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) {
6577 logevent("Access granted");
6578 s->we_are_in = TRUE;
6582 if (s->kbd_inter_running &&
6583 pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
6585 * This is either a further set-of-prompts packet
6586 * in keyboard-interactive authentication, or it's
6587 * the same one and we came back here with `gotit'
6588 * set. In the former case, we must reset the
6589 * curr_prompt variable.
6593 } else if (pktin->type == SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ) {
6594 /* FIXME: perhaps we should support this? */
6595 bombout(("PASSWD_CHANGEREQ not yet supported"));
6597 } else if (pktin->type != SSH2_MSG_USERAUTH_FAILURE) {
6598 bombout(("Strange packet received during authentication: type %d",
6606 * OK, we're now sitting on a USERAUTH_FAILURE message, so
6607 * we can look at the string in it and know what we can
6608 * helpfully try next.
6610 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) {
6613 ssh_pkt_getstring(pktin, &methods, &methlen);
6614 s->kbd_inter_running = FALSE;
6615 if (!ssh2_pkt_getbool(pktin)) {
6617 * We have received an unequivocal Access
6618 * Denied. This can translate to a variety of
6621 * - if we'd just tried "none" authentication,
6622 * it's not worth printing anything at all
6624 * - if we'd just tried a public key _offer_,
6625 * the message should be "Server refused our
6626 * key" (or no message at all if the key
6627 * came from Pageant)
6629 * - if we'd just tried anything else, the
6630 * message really should be "Access denied".
6632 * Additionally, if we'd just tried password
6633 * authentication, we should break out of this
6634 * whole loop so as to go back to the username
6635 * prompt (iff we're configured to allow
6636 * username change attempts).
6638 if (s->type == AUTH_TYPE_NONE) {
6640 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
6641 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
6642 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
6643 c_write_str(ssh, "Server refused our key\r\n");
6644 logevent("Server refused public key");
6645 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
6646 /* server declined keyboard-interactive; ignore */
6648 c_write_str(ssh, "Access denied\r\n");
6649 logevent("Access denied");
6650 if (s->type == AUTH_TYPE_PASSWORD &&
6651 ssh->cfg.change_username) {
6652 /* XXX perhaps we should allow
6653 * keyboard-interactive to do this too? */
6654 s->we_are_in = FALSE;
6659 c_write_str(ssh, "Further authentication required\r\n");
6660 logevent("Further authentication required");
6664 in_commasep_string("publickey", methods, methlen);
6666 in_commasep_string("password", methods, methlen);
6667 s->can_keyb_inter = ssh->cfg.try_ki_auth &&
6668 in_commasep_string("keyboard-interactive", methods, methlen);
6672 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6676 * Most password/passphrase prompts will be
6677 * non-echoing, so we set this to 0 by default.
6678 * Exception is that some keyboard-interactive prompts
6679 * can be echoing, in which case we'll set this to 1.
6683 if (!s->method && s->can_pubkey &&
6684 agent_exists() && !s->tried_agent) {
6686 * Attempt public-key authentication using Pageant.
6691 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6692 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
6694 s->tried_agent = TRUE;
6696 logevent("Pageant is running. Requesting keys.");
6698 /* Request the keys held by the agent. */
6699 PUT_32BIT(s->request, 1);
6700 s->request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
6701 if (!agent_query(s->request, 5, &r, &s->responselen,
6702 ssh_agent_callback, ssh)) {
6706 bombout(("Unexpected data from server while"
6707 " waiting for agent response"));
6710 } while (pktin || inlen > 0);
6711 r = ssh->agent_response;
6712 s->responselen = ssh->agent_response_len;
6714 s->response = (unsigned char *) r;
6715 if (s->response && s->responselen >= 5 &&
6716 s->response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
6717 s->p = s->response + 5;
6718 s->nkeys = GET_32BIT(s->p);
6720 logeventf(ssh, "Pageant has %d SSH-2 keys", s->nkeys);
6721 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
6724 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
6725 s->pklen = GET_32BIT(s->p);
6727 if (s->publickey_blob &&
6728 s->pklen == s->publickey_bloblen &&
6729 !memcmp(s->p, s->publickey_blob,
6730 s->publickey_bloblen)) {
6731 logevent("This key matches configured key file");
6732 s->tried_pubkey_config = 1;
6734 s->pkblob = (char *)s->p;
6736 s->alglen = GET_32BIT(s->pkblob);
6737 s->alg = s->pkblob + 4;
6738 s->commentlen = GET_32BIT(s->p);
6740 s->commentp = (char *)s->p;
6741 s->p += s->commentlen;
6742 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6743 ssh2_pkt_addstring(s->pktout, s->username);
6744 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6745 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6746 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
6747 ssh2_pkt_addstring_start(s->pktout);
6748 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
6749 ssh2_pkt_addstring_start(s->pktout);
6750 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
6751 ssh2_pkt_send(ssh, s->pktout);
6753 crWaitUntilV(pktin);
6754 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
6755 logevent("Key refused");
6759 if (flags & FLAG_VERBOSE) {
6760 c_write_str(ssh, "Authenticating with "
6762 c_write(ssh, s->commentp, s->commentlen);
6763 c_write_str(ssh, "\" from agent\r\n");
6767 * Server is willing to accept the key.
6768 * Construct a SIGN_REQUEST.
6770 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6771 ssh2_pkt_addstring(s->pktout, s->username);
6772 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6773 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6774 ssh2_pkt_addbool(s->pktout, TRUE);
6775 ssh2_pkt_addstring_start(s->pktout);
6776 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
6777 ssh2_pkt_addstring_start(s->pktout);
6778 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
6780 s->siglen = s->pktout->length - 5 + 4 + 20;
6781 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
6783 s->len = 1; /* message type */
6784 s->len += 4 + s->pklen; /* key blob */
6785 s->len += 4 + s->siglen; /* data to sign */
6786 s->len += 4; /* flags */
6787 s->agentreq = snewn(4 + s->len, char);
6788 PUT_32BIT(s->agentreq, s->len);
6789 s->q = s->agentreq + 4;
6790 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
6791 PUT_32BIT(s->q, s->pklen);
6793 memcpy(s->q, s->pkblob, s->pklen);
6795 PUT_32BIT(s->q, s->siglen);
6797 /* Now the data to be signed... */
6798 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
6799 PUT_32BIT(s->q, 20);
6802 memcpy(s->q, ssh->v2_session_id, 20);
6804 memcpy(s->q, s->pktout->data + 5,
6805 s->pktout->length - 5);
6806 s->q += s->pktout->length - 5;
6807 /* And finally the (zero) flags word. */
6809 if (!agent_query(s->agentreq, s->len + 4,
6811 ssh_agent_callback, ssh)) {
6815 bombout(("Unexpected data from server"
6816 " while waiting for agent"
6820 } while (pktin || inlen > 0);
6821 vret = ssh->agent_response;
6822 s->retlen = ssh->agent_response_len;
6827 if (s->ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
6828 logevent("Sending Pageant's response");
6829 ssh2_add_sigblob(ssh, s->pktout,
6830 s->pkblob, s->pklen,
6832 GET_32BIT(s->ret + 5));
6833 ssh2_pkt_send(ssh, s->pktout);
6838 ("Pageant failed to answer challenge");
6849 if (!s->method && s->can_pubkey && s->publickey_blob
6850 && !s->tried_pubkey_config) {
6851 unsigned char *pub_blob;
6852 char *algorithm, *comment;
6855 s->tried_pubkey_config = TRUE;
6857 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6858 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
6861 * Try the public key supplied in the configuration.
6863 * First, offer the public blob to see if the server is
6864 * willing to accept it.
6867 (unsigned char *)ssh2_userkey_loadpub(&ssh->cfg.keyfile,
6872 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6873 ssh2_pkt_addstring(s->pktout, s->username);
6874 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6875 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6876 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
6877 ssh2_pkt_addstring(s->pktout, algorithm);
6878 ssh2_pkt_addstring_start(s->pktout);
6879 ssh2_pkt_addstring_data(s->pktout, (char *)pub_blob,
6881 ssh2_pkt_send(ssh, s->pktout);
6882 logevent("Offered public key");
6884 crWaitUntilV(pktin);
6885 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
6887 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
6888 continue; /* key refused; give up on it */
6891 logevent("Offer of public key accepted");
6893 * Actually attempt a serious authentication using
6896 if (ssh2_userkey_encrypted(&ssh->cfg.keyfile, &comment)) {
6897 sprintf(s->pwprompt,
6898 "Passphrase for key \"%.100s\": ",
6904 if (flags & FLAG_VERBOSE) {
6905 c_write_str(ssh, "Authenticating with public key \"");
6906 c_write_str(ssh, comment);
6907 c_write_str(ssh, "\"\r\n");
6909 s->method = AUTH_PUBLICKEY_FILE;
6913 if (!s->method && s->can_keyb_inter && !s->kbd_inter_refused &&
6914 !s->kbd_inter_running) {
6915 s->method = AUTH_KEYBOARD_INTERACTIVE;
6916 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
6918 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6919 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
6921 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6922 ssh2_pkt_addstring(s->pktout, s->username);
6923 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6924 ssh2_pkt_addstring(s->pktout, "keyboard-interactive"); /* method */
6925 ssh2_pkt_addstring(s->pktout, ""); /* lang */
6926 ssh2_pkt_addstring(s->pktout, "");
6927 ssh2_pkt_send(ssh, s->pktout);
6929 crWaitUntilV(pktin);
6930 if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
6931 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE)
6933 logevent("Keyboard-interactive authentication refused");
6934 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
6935 s->kbd_inter_refused = TRUE; /* don't try it again */
6939 c_write_str(ssh, "Using keyboard-interactive authentication.\r\n");
6940 s->kbd_inter_running = TRUE;
6944 if (s->kbd_inter_running) {
6945 s->method = AUTH_KEYBOARD_INTERACTIVE;
6946 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
6948 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6949 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
6951 if (s->curr_prompt == 0) {
6953 * We've got a fresh USERAUTH_INFO_REQUEST.
6954 * Display header data, and start going through
6957 char *name, *inst, *lang;
6958 int name_len, inst_len, lang_len;
6960 ssh_pkt_getstring(pktin, &name, &name_len);
6961 ssh_pkt_getstring(pktin, &inst, &inst_len);
6962 ssh_pkt_getstring(pktin, &lang, &lang_len);
6964 c_write_untrusted(ssh, name, name_len);
6965 c_write_str(ssh, "\r\n");
6968 c_write_untrusted(ssh, inst, inst_len);
6969 c_write_str(ssh, "\r\n");
6971 s->num_prompts = ssh_pkt_getuint32(pktin);
6975 * If there are prompts remaining in the packet,
6976 * display one and get a response.
6978 if (s->curr_prompt < s->num_prompts) {
6982 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
6983 if (prompt_len > 0) {
6984 static const char trunc[] = "<prompt truncated>: ";
6985 static const int prlen = sizeof(s->pwprompt) -
6987 if (prompt_len > prlen) {
6988 memcpy(s->pwprompt, prompt, prlen);
6989 strcpy(s->pwprompt + prlen, trunc);
6991 memcpy(s->pwprompt, prompt, prompt_len);
6992 s->pwprompt[prompt_len] = '\0';
6996 "<server failed to send prompt>: ");
6998 s->echo = ssh2_pkt_getbool(pktin);
7004 if (!s->method && s->can_passwd) {
7005 s->method = AUTH_PASSWORD;
7006 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
7007 ssh->pkt_ctx |= SSH2_PKTCTX_PASSWORD;
7008 sprintf(s->pwprompt, "%.90s@%.90s's password: ", s->username,
7015 if (!ssh_get_line(s->pwprompt, s->password,
7016 sizeof(s->password), TRUE)) {
7018 * get_line failed to get a password (for
7019 * example because one was supplied on the
7020 * command line which has already failed to
7023 s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
7024 ssh2_pkt_adduint32(s->pktout,SSH2_DISCONNECT_BY_APPLICATION);
7025 ssh2_pkt_addstring(s->pktout, "No more passwords available"
7027 ssh2_pkt_addstring(s->pktout, "en"); /* language tag */
7028 ssh2_pkt_send_noqueue(ssh, s->pktout);
7029 logevent("Unable to authenticate");
7030 connection_fatal(ssh->frontend,
7031 "Unable to authenticate");
7032 ssh->close_expected = TRUE;
7033 ssh_closing((Plug)ssh, NULL, 0, 0);
7037 int ret; /* need not be saved across crReturn */
7038 c_write_untrusted(ssh, s->pwprompt, strlen(s->pwprompt));
7041 setup_userpass_input(ssh, s->password,
7042 sizeof(s->password), s->echo);
7044 crWaitUntilV(!pktin);
7045 ret = process_userpass_input(ssh, in, inlen);
7049 c_write_str(ssh, "\r\n");
7053 if (s->method == AUTH_PUBLICKEY_FILE) {
7055 * We have our passphrase. Now try the actual authentication.
7057 struct ssh2_userkey *key;
7058 const char *error = NULL;
7060 key = ssh2_load_userkey(&ssh->cfg.keyfile, s->password,
7062 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
7063 if (key == SSH2_WRONG_PASSPHRASE) {
7064 c_write_str(ssh, "Wrong passphrase\r\n");
7065 s->tried_pubkey_config = FALSE;
7067 c_write_str(ssh, "Unable to load private key (");
7068 c_write_str(ssh, error);
7069 c_write_str(ssh, ")\r\n");
7070 s->tried_pubkey_config = TRUE;
7072 /* Send a spurious AUTH_NONE to return to the top. */
7073 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
7074 ssh2_pkt_addstring(s->pktout, s->username);
7075 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
7076 ssh2_pkt_addstring(s->pktout, "none"); /* method */
7077 ssh2_pkt_send(ssh, s->pktout);
7078 s->type = AUTH_TYPE_NONE;
7080 unsigned char *pkblob, *sigblob, *sigdata;
7081 int pkblob_len, sigblob_len, sigdata_len;
7085 * We have loaded the private key and the server
7086 * has announced that it's willing to accept it.
7087 * Hallelujah. Generate a signature and send it.
7089 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
7090 ssh2_pkt_addstring(s->pktout, s->username);
7091 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
7092 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
7093 ssh2_pkt_addbool(s->pktout, TRUE);
7094 ssh2_pkt_addstring(s->pktout, key->alg->name);
7095 pkblob = key->alg->public_blob(key->data, &pkblob_len);
7096 ssh2_pkt_addstring_start(s->pktout);
7097 ssh2_pkt_addstring_data(s->pktout, (char *)pkblob, pkblob_len);
7100 * The data to be signed is:
7104 * followed by everything so far placed in the
7107 sigdata_len = s->pktout->length - 5 + 4 + 20;
7108 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
7110 sigdata = snewn(sigdata_len, unsigned char);
7112 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
7113 PUT_32BIT(sigdata+p, 20);
7116 memcpy(sigdata+p, ssh->v2_session_id, 20); p += 20;
7117 memcpy(sigdata+p, s->pktout->data + 5,
7118 s->pktout->length - 5);
7119 p += s->pktout->length - 5;
7120 assert(p == sigdata_len);
7121 sigblob = key->alg->sign(key->data, (char *)sigdata,
7122 sigdata_len, &sigblob_len);
7123 ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len,
7124 sigblob, sigblob_len);
7129 ssh2_pkt_send(ssh, s->pktout);
7130 s->type = AUTH_TYPE_PUBLICKEY;
7131 key->alg->freekey(key->data);
7133 } else if (s->method == AUTH_PASSWORD) {
7135 * We pad out the password packet to 256 bytes to make
7136 * it harder for an attacker to find the length of the
7139 * Anyone using a password longer than 256 bytes
7140 * probably doesn't have much to worry about from
7141 * people who find out how long their password is!
7143 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
7144 s->pktout->forcepad = 256;
7145 ssh2_pkt_addstring(s->pktout, s->username);
7146 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
7147 ssh2_pkt_addstring(s->pktout, "password");
7148 ssh2_pkt_addbool(s->pktout, FALSE);
7149 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
7150 ssh2_pkt_addstring(s->pktout, s->password);
7151 memset(s->password, 0, sizeof(s->password));
7152 end_log_omission(ssh, s->pktout);
7153 ssh2_pkt_send(ssh, s->pktout);
7154 logevent("Sent password");
7155 s->type = AUTH_TYPE_PASSWORD;
7156 } else if (s->method == AUTH_KEYBOARD_INTERACTIVE) {
7157 if (s->curr_prompt == 0) {
7158 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
7159 s->pktout->forcepad = 256;
7160 ssh2_pkt_adduint32(s->pktout, s->num_prompts);
7162 if (s->need_pw) { /* only add pw if we just got one! */
7163 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
7164 ssh2_pkt_addstring(s->pktout, s->password);
7165 memset(s->password, 0, sizeof(s->password));
7166 end_log_omission(ssh, s->pktout);
7169 if (s->curr_prompt >= s->num_prompts) {
7170 ssh2_pkt_send(ssh, s->pktout);
7173 * If there are prompts remaining, we set
7174 * `gotit' so that we won't attempt to get
7175 * another packet. Then we go back round the
7176 * loop and will end up retrieving another
7177 * prompt out of the existing packet. Funky or
7182 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
7184 c_write_str(ssh, "No supported authentication methods"
7185 " left to try!\r\n");
7186 logevent("No supported authentications offered."
7188 s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
7189 ssh2_pkt_adduint32(s->pktout, SSH2_DISCONNECT_BY_APPLICATION);
7190 ssh2_pkt_addstring(s->pktout, "No supported authentication"
7191 " methods available");
7192 ssh2_pkt_addstring(s->pktout, "en"); /* language tag */
7193 ssh2_pkt_send_noqueue(ssh, s->pktout);
7194 ssh->close_expected = TRUE;
7195 ssh_closing((Plug)ssh, NULL, 0, 0);
7199 } while (!s->we_are_in);
7202 * Now we're authenticated for the connection protocol. The
7203 * connection protocol will automatically have started at this
7204 * point; there's no need to send SERVICE_REQUEST.
7207 ssh->channels = newtree234(ssh_channelcmp);
7210 * Set up handlers for some connection protocol messages, so we
7211 * don't have to handle them repeatedly in this coroutine.
7213 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] =
7214 ssh2_msg_channel_window_adjust;
7215 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] =
7216 ssh2_msg_global_request;
7219 * Create the main session channel.
7221 if (!ssh->cfg.ssh_no_shell) {
7222 ssh->mainchan = snew(struct ssh_channel);
7223 ssh->mainchan->ssh = ssh;
7224 ssh->mainchan->localid = alloc_channel_id(ssh);
7225 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
7226 ssh2_pkt_addstring(s->pktout, "session");
7227 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->localid);
7228 ssh->mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
7229 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->v.v2.locwindow);/* our window size */
7230 ssh2_pkt_adduint32(s->pktout, OUR_V2_MAXPKT); /* our max pkt size */
7231 ssh2_pkt_send(ssh, s->pktout);
7232 crWaitUntilV(pktin);
7233 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
7234 bombout(("Server refused to open a session"));
7236 /* FIXME: error data comes back in FAILURE packet */
7238 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
7239 bombout(("Server's channel confirmation cited wrong channel"));
7242 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
7243 ssh->mainchan->halfopen = FALSE;
7244 ssh->mainchan->type = CHAN_MAINSESSION;
7245 ssh->mainchan->closes = 0;
7246 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
7247 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
7248 bufchain_init(&ssh->mainchan->v.v2.outbuffer);
7249 add234(ssh->channels, ssh->mainchan);
7250 update_specials_menu(ssh->frontend);
7251 logevent("Opened channel for session");
7253 ssh->mainchan = NULL;
7256 * Now we have a channel, make dispatch table entries for
7257 * general channel-based messages.
7259 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] =
7260 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] =
7261 ssh2_msg_channel_data;
7262 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_channel_eof;
7263 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_channel_close;
7264 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] =
7265 ssh2_msg_channel_open_confirmation;
7266 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] =
7267 ssh2_msg_channel_open_failure;
7268 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] =
7269 ssh2_msg_channel_request;
7270 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] =
7271 ssh2_msg_channel_open;
7274 * Potentially enable X11 forwarding.
7276 if (ssh->mainchan && ssh->cfg.x11_forward) {
7277 char proto[20], data[64];
7278 logevent("Requesting X11 forwarding");
7279 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
7280 data, sizeof(data), ssh->cfg.x11_auth);
7281 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
7282 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7283 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
7284 ssh2_pkt_addstring(s->pktout, "x11-req");
7285 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7286 ssh2_pkt_addbool(s->pktout, 0); /* many connections */
7287 ssh2_pkt_addstring(s->pktout, proto);
7288 ssh2_pkt_addstring(s->pktout, data);
7289 ssh2_pkt_adduint32(s->pktout, x11_get_screen_number(ssh->cfg.x11_display));
7290 ssh2_pkt_send(ssh, s->pktout);
7292 crWaitUntilV(pktin);
7294 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7295 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
7296 bombout(("Unexpected response to X11 forwarding request:"
7297 " packet type %d", pktin->type));
7300 logevent("X11 forwarding refused");
7302 logevent("X11 forwarding enabled");
7303 ssh->X11_fwd_enabled = TRUE;
7308 * Enable port forwardings.
7310 ssh_setup_portfwd(ssh, &ssh->cfg);
7313 * Potentially enable agent forwarding.
7315 if (ssh->mainchan && ssh->cfg.agentfwd && agent_exists()) {
7316 logevent("Requesting OpenSSH-style agent forwarding");
7317 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7318 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
7319 ssh2_pkt_addstring(s->pktout, "auth-agent-req@openssh.com");
7320 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7321 ssh2_pkt_send(ssh, s->pktout);
7323 crWaitUntilV(pktin);
7325 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7326 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
7327 bombout(("Unexpected response to agent forwarding request:"
7328 " packet type %d", pktin->type));
7331 logevent("Agent forwarding refused");
7333 logevent("Agent forwarding enabled");
7334 ssh->agentfwd_enabled = TRUE;
7339 * Now allocate a pty for the session.
7341 if (ssh->mainchan && !ssh->cfg.nopty) {
7342 /* Unpick the terminal-speed string. */
7343 /* XXX perhaps we should allow no speeds to be sent. */
7344 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
7345 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
7346 /* Build the pty request. */
7347 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7348 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
7349 ssh2_pkt_addstring(s->pktout, "pty-req");
7350 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7351 ssh2_pkt_addstring(s->pktout, ssh->cfg.termtype);
7352 ssh2_pkt_adduint32(s->pktout, ssh->term_width);
7353 ssh2_pkt_adduint32(s->pktout, ssh->term_height);
7354 ssh2_pkt_adduint32(s->pktout, 0); /* pixel width */
7355 ssh2_pkt_adduint32(s->pktout, 0); /* pixel height */
7356 ssh2_pkt_addstring_start(s->pktout);
7357 parse_ttymodes(ssh, ssh->cfg.ttymodes,
7358 ssh2_send_ttymode, (void *)s->pktout);
7359 ssh2_pkt_addbyte(s->pktout, SSH2_TTY_OP_ISPEED);
7360 ssh2_pkt_adduint32(s->pktout, ssh->ispeed);
7361 ssh2_pkt_addbyte(s->pktout, SSH2_TTY_OP_OSPEED);
7362 ssh2_pkt_adduint32(s->pktout, ssh->ospeed);
7363 ssh2_pkt_addstring_data(s->pktout, "\0", 1); /* TTY_OP_END */
7364 ssh2_pkt_send(ssh, s->pktout);
7365 ssh->state = SSH_STATE_INTERMED;
7367 crWaitUntilV(pktin);
7369 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7370 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
7371 bombout(("Unexpected response to pty request:"
7372 " packet type %d", pktin->type));
7375 c_write_str(ssh, "Server refused to allocate pty\r\n");
7376 ssh->editing = ssh->echoing = 1;
7378 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
7379 ssh->ospeed, ssh->ispeed);
7382 ssh->editing = ssh->echoing = 1;
7386 * Send environment variables.
7388 * Simplest thing here is to send all the requests at once, and
7389 * then wait for a whole bunch of successes or failures.
7391 if (ssh->mainchan && *ssh->cfg.environmt) {
7392 char *e = ssh->cfg.environmt;
7393 char *var, *varend, *val;
7399 while (*e && *e != '\t') e++;
7401 if (*e == '\t') e++;
7406 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7407 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
7408 ssh2_pkt_addstring(s->pktout, "env");
7409 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7410 ssh2_pkt_addstring_start(s->pktout);
7411 ssh2_pkt_addstring_data(s->pktout, var, varend-var);
7412 ssh2_pkt_addstring(s->pktout, val);
7413 ssh2_pkt_send(ssh, s->pktout);
7418 logeventf(ssh, "Sent %d environment variables", s->num_env);
7421 s->env_left = s->num_env;
7423 while (s->env_left > 0) {
7424 crWaitUntilV(pktin);
7426 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7427 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
7428 bombout(("Unexpected response to environment request:"
7429 " packet type %d", pktin->type));
7439 if (s->env_ok == s->num_env) {
7440 logevent("All environment variables successfully set");
7441 } else if (s->env_ok == 0) {
7442 logevent("All environment variables refused");
7443 c_write_str(ssh, "Server refused to set environment variables\r\n");
7445 logeventf(ssh, "%d environment variables refused",
7446 s->num_env - s->env_ok);
7447 c_write_str(ssh, "Server refused to set all environment variables\r\n");
7452 * Start a shell or a remote command. We may have to attempt
7453 * this twice if the config data has provided a second choice
7456 if (ssh->mainchan) while (1) {
7460 if (ssh->fallback_cmd) {
7461 subsys = ssh->cfg.ssh_subsys2;
7462 cmd = ssh->cfg.remote_cmd_ptr2;
7464 subsys = ssh->cfg.ssh_subsys;
7465 cmd = ssh->cfg.remote_cmd_ptr;
7466 if (!cmd) cmd = ssh->cfg.remote_cmd;
7469 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7470 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
7472 ssh2_pkt_addstring(s->pktout, "subsystem");
7473 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7474 ssh2_pkt_addstring(s->pktout, cmd);
7476 ssh2_pkt_addstring(s->pktout, "exec");
7477 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7478 ssh2_pkt_addstring(s->pktout, cmd);
7480 ssh2_pkt_addstring(s->pktout, "shell");
7481 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7483 ssh2_pkt_send(ssh, s->pktout);
7485 crWaitUntilV(pktin);
7487 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7488 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
7489 bombout(("Unexpected response to shell/command request:"
7490 " packet type %d", pktin->type));
7494 * We failed to start the command. If this is the
7495 * fallback command, we really are finished; if it's
7496 * not, and if the fallback command exists, try falling
7497 * back to it before complaining.
7499 if (!ssh->fallback_cmd && ssh->cfg.remote_cmd_ptr2 != NULL) {
7500 logevent("Primary command failed; attempting fallback");
7501 ssh->fallback_cmd = TRUE;
7504 bombout(("Server refused to start a shell/command"));
7507 logevent("Started a shell/command");
7512 ssh->state = SSH_STATE_SESSION;
7513 if (ssh->size_needed)
7514 ssh_size(ssh, ssh->term_width, ssh->term_height);
7515 if (ssh->eof_needed)
7516 ssh_special(ssh, TS_EOF);
7522 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
7527 s->try_send = FALSE;
7531 * _All_ the connection-layer packets we expect to
7532 * receive are now handled by the dispatch table.
7533 * Anything that reaches here must be bogus.
7536 bombout(("Strange packet received: type %d", pktin->type));
7538 } else if (ssh->mainchan) {
7540 * We have spare data. Add it to the channel buffer.
7542 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
7547 struct ssh_channel *c;
7549 * Try to send data on all channels if we can.
7551 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++)
7552 ssh2_try_send_and_unthrottle(c);
7560 * Handlers for SSH-2 messages that might arrive at any moment.
7562 static void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin)
7564 /* log reason code in disconnect message */
7566 int nowlen, reason, msglen;
7568 reason = ssh_pkt_getuint32(pktin);
7569 ssh_pkt_getstring(pktin, &msg, &msglen);
7571 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
7572 buf = dupprintf("Received disconnect message (%s)",
7573 ssh2_disconnect_reasons[reason]);
7575 buf = dupprintf("Received disconnect message (unknown"
7576 " type %d)", reason);
7580 buf = dupprintf("Disconnection message text: %n%.*s",
7581 &nowlen, msglen, msg);
7583 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
7585 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
7586 ssh2_disconnect_reasons[reason] : "unknown",
7591 static void ssh2_msg_debug(Ssh ssh, struct Packet *pktin)
7593 /* log the debug message */
7598 /* XXX maybe we should actually take notice of this */
7599 always_display = ssh2_pkt_getbool(pktin);
7600 ssh_pkt_getstring(pktin, &msg, &msglen);
7602 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
7605 static void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin)
7607 struct Packet *pktout;
7608 pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
7609 ssh2_pkt_adduint32(pktout, pktin->sequence);
7611 * UNIMPLEMENTED messages MUST appear in the same order as the
7612 * messages they respond to. Hence, never queue them.
7614 ssh2_pkt_send_noqueue(ssh, pktout);
7618 * Handle the top-level SSH-2 protocol.
7620 static void ssh2_protocol_setup(Ssh ssh)
7625 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
7627 for (i = 0; i < 256; i++)
7628 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
7631 * Any message we actually understand, we set to NULL so that
7632 * the coroutines will get it.
7634 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = NULL;
7635 ssh->packet_dispatch[SSH2_MSG_SERVICE_REQUEST] = NULL;
7636 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = NULL;
7637 ssh->packet_dispatch[SSH2_MSG_KEXINIT] = NULL;
7638 ssh->packet_dispatch[SSH2_MSG_NEWKEYS] = NULL;
7639 ssh->packet_dispatch[SSH2_MSG_KEXDH_INIT] = NULL;
7640 ssh->packet_dispatch[SSH2_MSG_KEXDH_REPLY] = NULL;
7641 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = NULL; duplicate case value */
7642 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = NULL; duplicate case value */
7643 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_INIT] = NULL;
7644 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REPLY] = NULL;
7645 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = NULL;
7646 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = NULL;
7647 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = NULL;
7648 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
7649 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = NULL;
7650 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = NULL; duplicate case value */
7651 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = NULL; duplicate case value */
7652 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = NULL;
7653 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = NULL;
7654 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = NULL;
7655 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = NULL;
7656 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = NULL;
7657 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = NULL;
7658 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = NULL;
7659 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = NULL;
7660 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = NULL;
7661 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = NULL;
7662 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = NULL;
7663 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = NULL;
7664 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = NULL;
7665 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = NULL;
7666 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = NULL;
7669 * These special message types we install handlers for.
7671 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
7672 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with SSH-1 */
7673 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
7676 static void ssh2_timer(void *ctx, long now)
7680 if (ssh->state == SSH_STATE_CLOSED)
7683 if (!ssh->kex_in_progress && ssh->cfg.ssh_rekey_time != 0 &&
7684 now - ssh->next_rekey >= 0) {
7685 do_ssh2_transport(ssh, "timeout", -1, NULL);
7689 static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
7690 struct Packet *pktin)
7692 unsigned char *in = (unsigned char *)vin;
7693 if (ssh->state == SSH_STATE_CLOSED)
7697 ssh->incoming_data_size += pktin->encrypted_len;
7698 if (!ssh->kex_in_progress &&
7699 ssh->max_data_size != 0 &&
7700 ssh->incoming_data_size > ssh->max_data_size)
7701 do_ssh2_transport(ssh, "too much data received", -1, NULL);
7704 if (pktin && ssh->packet_dispatch[pktin->type]) {
7705 ssh->packet_dispatch[pktin->type](ssh, pktin);
7709 if (!ssh->protocol_initial_phase_done ||
7710 (pktin && pktin->type >= 20 && pktin->type < 50)) {
7711 if (do_ssh2_transport(ssh, in, inlen, pktin) &&
7712 !ssh->protocol_initial_phase_done) {
7713 ssh->protocol_initial_phase_done = TRUE;
7715 * Allow authconn to initialise itself.
7717 do_ssh2_authconn(ssh, NULL, 0, NULL);
7720 do_ssh2_authconn(ssh, in, inlen, pktin);
7725 * Called to set up the connection.
7727 * Returns an error message, or NULL on success.
7729 static const char *ssh_init(void *frontend_handle, void **backend_handle,
7731 char *host, int port, char **realhost, int nodelay,
7737 ssh = snew(struct ssh_tag);
7738 ssh->cfg = *cfg; /* STRUCTURE COPY */
7739 ssh->version = 0; /* when not ready yet */
7742 ssh->v1_cipher_ctx = NULL;
7743 ssh->crcda_ctx = NULL;
7744 ssh->cscipher = NULL;
7745 ssh->cs_cipher_ctx = NULL;
7746 ssh->sccipher = NULL;
7747 ssh->sc_cipher_ctx = NULL;
7749 ssh->cs_mac_ctx = NULL;
7751 ssh->sc_mac_ctx = NULL;
7753 ssh->cs_comp_ctx = NULL;
7755 ssh->sc_comp_ctx = NULL;
7757 ssh->kex_ctx = NULL;
7758 ssh->hostkey = NULL;
7760 ssh->close_expected = FALSE;
7761 ssh->state = SSH_STATE_PREPACKET;
7762 ssh->size_needed = FALSE;
7763 ssh->eof_needed = FALSE;
7766 ssh->deferred_send_data = NULL;
7767 ssh->deferred_len = 0;
7768 ssh->deferred_size = 0;
7769 ssh->fallback_cmd = 0;
7771 ssh->x11auth = NULL;
7772 ssh->v1_compressing = FALSE;
7773 ssh->v2_outgoing_sequence = 0;
7774 ssh->ssh1_rdpkt_crstate = 0;
7775 ssh->ssh2_rdpkt_crstate = 0;
7776 ssh->do_ssh_init_crstate = 0;
7777 ssh->ssh_gotdata_crstate = 0;
7778 ssh->do_ssh1_connection_crstate = 0;
7779 ssh->do_ssh1_login_crstate = 0;
7780 ssh->do_ssh2_transport_crstate = 0;
7781 ssh->do_ssh2_authconn_crstate = 0;
7782 ssh->do_ssh_init_state = NULL;
7783 ssh->do_ssh1_login_state = NULL;
7784 ssh->do_ssh2_transport_state = NULL;
7785 ssh->do_ssh2_authconn_state = NULL;
7786 ssh->mainchan = NULL;
7787 ssh->throttled_all = 0;
7788 ssh->v1_stdout_throttling = 0;
7790 ssh->queuelen = ssh->queuesize = 0;
7791 ssh->queueing = FALSE;
7792 ssh->qhead = ssh->qtail = NULL;
7793 ssh->deferred_rekey_reason = NULL;
7794 bufchain_init(&ssh->queued_incoming_data);
7795 ssh->frozen = FALSE;
7797 *backend_handle = ssh;
7800 if (crypto_startup() == 0)
7801 return "Microsoft high encryption pack not installed!";
7804 ssh->frontend = frontend_handle;
7805 ssh->term_width = ssh->cfg.width;
7806 ssh->term_height = ssh->cfg.height;
7808 ssh->channels = NULL;
7809 ssh->rportfwds = NULL;
7810 ssh->portfwds = NULL;
7815 ssh->v1_throttle_count = 0;
7816 ssh->overall_bufsize = 0;
7817 ssh->fallback_cmd = 0;
7819 ssh->protocol = NULL;
7821 ssh->protocol_initial_phase_done = FALSE;
7825 ssh->incoming_data_size = ssh->outgoing_data_size =
7826 ssh->deferred_data_size = 0L;
7827 ssh->max_data_size = parse_blocksize(ssh->cfg.ssh_rekey_data);
7828 ssh->kex_in_progress = FALSE;
7830 p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
7839 static void ssh_free(void *handle)
7841 Ssh ssh = (Ssh) handle;
7842 struct ssh_channel *c;
7843 struct ssh_rportfwd *pf;
7845 if (ssh->v1_cipher_ctx)
7846 ssh->cipher->free_context(ssh->v1_cipher_ctx);
7847 if (ssh->cs_cipher_ctx)
7848 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
7849 if (ssh->sc_cipher_ctx)
7850 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
7851 if (ssh->cs_mac_ctx)
7852 ssh->csmac->free_context(ssh->cs_mac_ctx);
7853 if (ssh->sc_mac_ctx)
7854 ssh->scmac->free_context(ssh->sc_mac_ctx);
7855 if (ssh->cs_comp_ctx) {
7857 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
7859 zlib_compress_cleanup(ssh->cs_comp_ctx);
7861 if (ssh->sc_comp_ctx) {
7863 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
7865 zlib_decompress_cleanup(ssh->sc_comp_ctx);
7868 dh_cleanup(ssh->kex_ctx);
7869 sfree(ssh->savedhost);
7871 while (ssh->queuelen-- > 0)
7872 ssh_free_packet(ssh->queue[ssh->queuelen]);
7875 while (ssh->qhead) {
7876 struct queued_handler *qh = ssh->qhead;
7877 ssh->qhead = qh->next;
7880 ssh->qhead = ssh->qtail = NULL;
7882 if (ssh->channels) {
7883 while ((c = delpos234(ssh->channels, 0)) != NULL) {
7886 if (c->u.x11.s != NULL)
7887 x11_close(c->u.x11.s);
7890 if (c->u.pfd.s != NULL)
7891 pfd_close(c->u.pfd.s);
7896 freetree234(ssh->channels);
7897 ssh->channels = NULL;
7900 if (ssh->rportfwds) {
7901 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
7903 freetree234(ssh->rportfwds);
7904 ssh->rportfwds = NULL;
7906 sfree(ssh->deferred_send_data);
7908 x11_free_auth(ssh->x11auth);
7909 sfree(ssh->do_ssh_init_state);
7910 sfree(ssh->do_ssh1_login_state);
7911 sfree(ssh->do_ssh2_transport_state);
7912 sfree(ssh->do_ssh2_authconn_state);
7913 if (ssh->crcda_ctx) {
7914 crcda_free_context(ssh->crcda_ctx);
7915 ssh->crcda_ctx = NULL;
7918 ssh_do_close(ssh, TRUE);
7919 expire_timer_context(ssh);
7921 pinger_free(ssh->pinger);
7922 bufchain_clear(&ssh->queued_incoming_data);
7929 * Reconfigure the SSH backend.
7931 static void ssh_reconfig(void *handle, Config *cfg)
7933 Ssh ssh = (Ssh) handle;
7934 char *rekeying = NULL, rekey_mandatory = FALSE;
7935 unsigned long old_max_data_size;
7937 pinger_reconfig(ssh->pinger, &ssh->cfg, cfg);
7938 ssh_setup_portfwd(ssh, cfg);
7940 if (ssh->cfg.ssh_rekey_time != cfg->ssh_rekey_time &&
7941 cfg->ssh_rekey_time != 0) {
7942 long new_next = ssh->last_rekey + cfg->ssh_rekey_time*60*TICKSPERSEC;
7943 long now = GETTICKCOUNT();
7945 if (new_next - now < 0) {
7946 rekeying = "timeout shortened";
7948 ssh->next_rekey = schedule_timer(new_next - now, ssh2_timer, ssh);
7952 old_max_data_size = ssh->max_data_size;
7953 ssh->max_data_size = parse_blocksize(cfg->ssh_rekey_data);
7954 if (old_max_data_size != ssh->max_data_size &&
7955 ssh->max_data_size != 0) {
7956 if (ssh->outgoing_data_size > ssh->max_data_size ||
7957 ssh->incoming_data_size > ssh->max_data_size)
7958 rekeying = "data limit lowered";
7961 if (ssh->cfg.compression != cfg->compression) {
7962 rekeying = "compression setting changed";
7963 rekey_mandatory = TRUE;
7966 if (ssh->cfg.ssh2_des_cbc != cfg->ssh2_des_cbc ||
7967 memcmp(ssh->cfg.ssh_cipherlist, cfg->ssh_cipherlist,
7968 sizeof(ssh->cfg.ssh_cipherlist))) {
7969 rekeying = "cipher settings changed";
7970 rekey_mandatory = TRUE;
7973 ssh->cfg = *cfg; /* STRUCTURE COPY */
7976 if (!ssh->kex_in_progress) {
7977 do_ssh2_transport(ssh, rekeying, -1, NULL);
7978 } else if (rekey_mandatory) {
7979 ssh->deferred_rekey_reason = rekeying;
7985 * Called to send data down the Telnet connection.
7987 static int ssh_send(void *handle, char *buf, int len)
7989 Ssh ssh = (Ssh) handle;
7991 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
7994 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
7996 return ssh_sendbuffer(ssh);
8000 * Called to query the current amount of buffered stdin data.
8002 static int ssh_sendbuffer(void *handle)
8004 Ssh ssh = (Ssh) handle;
8007 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
8011 * If the SSH socket itself has backed up, add the total backup
8012 * size on that to any individual buffer on the stdin channel.
8015 if (ssh->throttled_all)
8016 override_value = ssh->overall_bufsize;
8018 if (ssh->version == 1) {
8019 return override_value;
8020 } else if (ssh->version == 2) {
8021 if (!ssh->mainchan || ssh->mainchan->closes > 0)
8022 return override_value;
8024 return (override_value +
8025 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
8032 * Called to set the size of the window from SSH's POV.
8034 static void ssh_size(void *handle, int width, int height)
8036 Ssh ssh = (Ssh) handle;
8037 struct Packet *pktout;
8039 ssh->term_width = width;
8040 ssh->term_height = height;
8042 switch (ssh->state) {
8043 case SSH_STATE_BEFORE_SIZE:
8044 case SSH_STATE_PREPACKET:
8045 case SSH_STATE_CLOSED:
8046 break; /* do nothing */
8047 case SSH_STATE_INTERMED:
8048 ssh->size_needed = TRUE; /* buffer for later */
8050 case SSH_STATE_SESSION:
8051 if (!ssh->cfg.nopty) {
8052 if (ssh->version == 1) {
8053 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
8054 PKT_INT, ssh->term_height,
8055 PKT_INT, ssh->term_width,
8056 PKT_INT, 0, PKT_INT, 0, PKT_END);
8057 } else if (ssh->mainchan) {
8058 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8059 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
8060 ssh2_pkt_addstring(pktout, "window-change");
8061 ssh2_pkt_addbool(pktout, 0);
8062 ssh2_pkt_adduint32(pktout, ssh->term_width);
8063 ssh2_pkt_adduint32(pktout, ssh->term_height);
8064 ssh2_pkt_adduint32(pktout, 0);
8065 ssh2_pkt_adduint32(pktout, 0);
8066 ssh2_pkt_send(ssh, pktout);
8074 * Return a list of the special codes that make sense in this
8077 static const struct telnet_special *ssh_get_specials(void *handle)
8079 static const struct telnet_special ssh1_ignore_special[] = {
8080 {"IGNORE message", TS_NOP}
8082 static const struct telnet_special ssh2_transport_specials[] = {
8083 {"IGNORE message", TS_NOP},
8084 {"Repeat key exchange", TS_REKEY},
8086 static const struct telnet_special ssh2_session_specials[] = {
8089 /* These are the signal names defined by draft-ietf-secsh-connect-23.
8090 * They include all the ISO C signals, but are a subset of the POSIX
8091 * required signals. */
8092 {"SIGINT (Interrupt)", TS_SIGINT},
8093 {"SIGTERM (Terminate)", TS_SIGTERM},
8094 {"SIGKILL (Kill)", TS_SIGKILL},
8095 {"SIGQUIT (Quit)", TS_SIGQUIT},
8096 {"SIGHUP (Hangup)", TS_SIGHUP},
8097 {"More signals", TS_SUBMENU},
8098 {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM},
8099 {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL},
8100 {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV},
8101 {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2},
8104 static const struct telnet_special specials_end[] = {
8107 /* XXX review this length for any changes: */
8108 static struct telnet_special ssh_specials[lenof(ssh2_transport_specials) +
8109 lenof(ssh2_session_specials) +
8110 lenof(specials_end)];
8111 Ssh ssh = (Ssh) handle;
8113 #define ADD_SPECIALS(name) \
8115 assert((i + lenof(name)) <= lenof(ssh_specials)); \
8116 memcpy(&ssh_specials[i], name, sizeof name); \
8120 if (ssh->version == 1) {
8121 /* Don't bother offering IGNORE if we've decided the remote
8122 * won't cope with it, since we wouldn't bother sending it if
8124 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
8125 ADD_SPECIALS(ssh1_ignore_special);
8126 } else if (ssh->version == 2) {
8127 ADD_SPECIALS(ssh2_transport_specials);
8129 ADD_SPECIALS(ssh2_session_specials);
8130 } /* else we're not ready yet */
8133 ADD_SPECIALS(specials_end);
8134 return ssh_specials;
8142 * Send Telnet special codes. TS_EOF is useful for `plink', so you
8143 * can send an EOF and collect resulting output (e.g. `plink
8146 static void ssh_special(void *handle, Telnet_Special code)
8148 Ssh ssh = (Ssh) handle;
8149 struct Packet *pktout;
8151 if (code == TS_EOF) {
8152 if (ssh->state != SSH_STATE_SESSION) {
8154 * Buffer the EOF in case we are pre-SESSION, so we can
8155 * send it as soon as we reach SESSION.
8158 ssh->eof_needed = TRUE;
8161 if (ssh->version == 1) {
8162 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
8163 } else if (ssh->mainchan) {
8164 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
8165 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
8166 ssh2_pkt_send(ssh, pktout);
8167 ssh->send_ok = 0; /* now stop trying to read from stdin */
8169 logevent("Sent EOF message");
8170 } else if (code == TS_PING || code == TS_NOP) {
8171 if (ssh->state == SSH_STATE_CLOSED
8172 || ssh->state == SSH_STATE_PREPACKET) return;
8173 if (ssh->version == 1) {
8174 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
8175 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
8177 pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
8178 ssh2_pkt_addstring_start(pktout);
8179 ssh2_pkt_send_noqueue(ssh, pktout);
8181 } else if (code == TS_REKEY) {
8182 if (!ssh->kex_in_progress && ssh->version == 2) {
8183 do_ssh2_transport(ssh, "at user request", -1, NULL);
8185 } else if (code == TS_BRK) {
8186 if (ssh->state == SSH_STATE_CLOSED
8187 || ssh->state == SSH_STATE_PREPACKET) return;
8188 if (ssh->version == 1) {
8189 logevent("Unable to send BREAK signal in SSH-1");
8190 } else if (ssh->mainchan) {
8191 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8192 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
8193 ssh2_pkt_addstring(pktout, "break");
8194 ssh2_pkt_addbool(pktout, 0);
8195 ssh2_pkt_adduint32(pktout, 0); /* default break length */
8196 ssh2_pkt_send(ssh, pktout);
8199 /* Is is a POSIX signal? */
8200 char *signame = NULL;
8201 if (code == TS_SIGABRT) signame = "ABRT";
8202 if (code == TS_SIGALRM) signame = "ALRM";
8203 if (code == TS_SIGFPE) signame = "FPE";
8204 if (code == TS_SIGHUP) signame = "HUP";
8205 if (code == TS_SIGILL) signame = "ILL";
8206 if (code == TS_SIGINT) signame = "INT";
8207 if (code == TS_SIGKILL) signame = "KILL";
8208 if (code == TS_SIGPIPE) signame = "PIPE";
8209 if (code == TS_SIGQUIT) signame = "QUIT";
8210 if (code == TS_SIGSEGV) signame = "SEGV";
8211 if (code == TS_SIGTERM) signame = "TERM";
8212 if (code == TS_SIGUSR1) signame = "USR1";
8213 if (code == TS_SIGUSR2) signame = "USR2";
8214 /* The SSH-2 protocol does in principle support arbitrary named
8215 * signals, including signame@domain, but we don't support those. */
8217 /* It's a signal. */
8218 if (ssh->version == 2 && ssh->mainchan) {
8219 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8220 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
8221 ssh2_pkt_addstring(pktout, "signal");
8222 ssh2_pkt_addbool(pktout, 0);
8223 ssh2_pkt_addstring(pktout, signame);
8224 ssh2_pkt_send(ssh, pktout);
8225 logeventf(ssh, "Sent signal SIG%s", signame);
8228 /* Never heard of it. Do nothing */
8233 void *new_sock_channel(void *handle, Socket s)
8235 Ssh ssh = (Ssh) handle;
8236 struct ssh_channel *c;
8237 c = snew(struct ssh_channel);
8242 c->localid = alloc_channel_id(ssh);
8244 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
8246 bufchain_init(&c->v.v2.outbuffer);
8247 add234(ssh->channels, c);
8253 * This is called when stdout/stderr (the entity to which
8254 * from_backend sends data) manages to clear some backlog.
8256 static void ssh_unthrottle(void *handle, int bufsize)
8258 Ssh ssh = (Ssh) handle;
8259 if (ssh->version == 1) {
8260 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
8261 ssh->v1_stdout_throttling = 0;
8262 ssh1_throttle(ssh, -1);
8265 if (ssh->mainchan && ssh->mainchan->closes == 0)
8266 ssh2_set_window(ssh->mainchan, OUR_V2_WINSIZE - bufsize);
8270 void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
8272 struct ssh_channel *c = (struct ssh_channel *)channel;
8274 struct Packet *pktout;
8276 logeventf(ssh, "Opening forwarded connection to %s:%d", hostname, port);
8278 if (ssh->version == 1) {
8279 send_packet(ssh, SSH1_MSG_PORT_OPEN,
8280 PKT_INT, c->localid,
8283 /* PKT_STR, <org:orgport>, */
8286 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
8287 ssh2_pkt_addstring(pktout, "direct-tcpip");
8288 ssh2_pkt_adduint32(pktout, c->localid);
8289 c->v.v2.locwindow = OUR_V2_WINSIZE;
8290 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */
8291 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
8292 ssh2_pkt_addstring(pktout, hostname);
8293 ssh2_pkt_adduint32(pktout, port);
8295 * We make up values for the originator data; partly it's
8296 * too much hassle to keep track, and partly I'm not
8297 * convinced the server should be told details like that
8298 * about my local network configuration.
8300 ssh2_pkt_addstring(pktout, "client-side-connection");
8301 ssh2_pkt_adduint32(pktout, 0);
8302 ssh2_pkt_send(ssh, pktout);
8306 static Socket ssh_socket(void *handle)
8308 Ssh ssh = (Ssh) handle;
8312 static int ssh_sendok(void *handle)
8314 Ssh ssh = (Ssh) handle;
8315 return ssh->send_ok;
8318 static int ssh_ldisc(void *handle, int option)
8320 Ssh ssh = (Ssh) handle;
8321 if (option == LD_ECHO)
8322 return ssh->echoing;
8323 if (option == LD_EDIT)
8324 return ssh->editing;
8328 static void ssh_provide_ldisc(void *handle, void *ldisc)
8330 Ssh ssh = (Ssh) handle;
8334 static void ssh_provide_logctx(void *handle, void *logctx)
8336 Ssh ssh = (Ssh) handle;
8337 ssh->logctx = logctx;
8340 static int ssh_return_exitcode(void *handle)
8342 Ssh ssh = (Ssh) handle;
8346 return (ssh->exitcode >= 0 ? ssh->exitcode : 0);
8350 * cfg_info for SSH is the currently running version of the
8351 * protocol. (1 for 1; 2 for 2; 0 for not-decided-yet.)
8353 static int ssh_cfg_info(void *handle)
8355 Ssh ssh = (Ssh) handle;
8356 return ssh->version;
8360 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
8361 * that fails. This variable is the means by which scp.c can reach
8362 * into the SSH code and find out which one it got.
8364 extern int ssh_fallback_cmd(void *handle)
8366 Ssh ssh = (Ssh) handle;
8367 return ssh->fallback_cmd;
8370 Backend ssh_backend = {
8380 ssh_return_exitcode,