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 "host not allowed to connect",
135 "key exchange failed",
136 "host authentication failed",
139 "service not available",
140 "protocol version not supported",
141 "host key not verifiable",
144 "too many connections",
145 "auth cancelled by user",
146 "no more auth methods available",
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 /* Maximum length of passwords/passphrases (arbitrary) */
463 #define SSH_MAX_PASSWORD_LEN 100
465 const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
467 const static struct ssh_mac *macs[] = {
468 &ssh_hmac_sha1, &ssh_hmac_sha1_96, &ssh_hmac_md5
470 const static struct ssh_mac *buggymacs[] = {
471 &ssh_hmac_sha1_buggy, &ssh_hmac_sha1_96_buggy, &ssh_hmac_md5
474 static void *ssh_comp_none_init(void)
478 static void ssh_comp_none_cleanup(void *handle)
481 static int ssh_comp_none_block(void *handle, unsigned char *block, int len,
482 unsigned char **outblock, int *outlen)
486 static int ssh_comp_none_disable(void *handle)
490 const static struct ssh_compress ssh_comp_none = {
492 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
493 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
494 ssh_comp_none_disable, NULL
496 extern const struct ssh_compress ssh_zlib;
497 const static struct ssh_compress *compressions[] = {
498 &ssh_zlib, &ssh_comp_none
501 enum { /* channel types */
506 CHAN_SOCKDATA_DORMANT /* one the remote hasn't confirmed */
510 * 2-3-4 tree storing channels.
513 Ssh ssh; /* pointer back to main context */
514 unsigned remoteid, localid;
516 /* True if we opened this channel but server hasn't confirmed. */
519 * In SSH-1, this value contains four bits:
521 * 1 We have sent SSH1_MSG_CHANNEL_CLOSE.
522 * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
523 * 4 We have received SSH1_MSG_CHANNEL_CLOSE.
524 * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
526 * A channel is completely finished with when all four bits are set.
530 struct ssh1_data_channel {
533 struct ssh2_data_channel {
535 unsigned remwindow, remmaxpkt;
540 struct ssh_agent_channel {
541 unsigned char *message;
542 unsigned char msglen[4];
543 unsigned lensofar, totallen;
545 struct ssh_x11_channel {
548 struct ssh_pfd_channel {
555 * 2-3-4 tree storing remote->local port forwardings. SSH-1 and SSH-2
556 * use this structure in different ways, reflecting SSH-2's
557 * altogether saner approach to port forwarding.
559 * In SSH-1, you arrange a remote forwarding by sending the server
560 * the remote port number, and the local destination host:port.
561 * When a connection comes in, the server sends you back that
562 * host:port pair, and you connect to it. This is a ready-made
563 * security hole if you're not on the ball: a malicious server
564 * could send you back _any_ host:port pair, so if you trustingly
565 * connect to the address it gives you then you've just opened the
566 * entire inside of your corporate network just by connecting
567 * through it to a dodgy SSH server. Hence, we must store a list of
568 * host:port pairs we _are_ trying to forward to, and reject a
569 * connection request from the server if it's not in the list.
571 * In SSH-2, each side of the connection minds its own business and
572 * doesn't send unnecessary information to the other. You arrange a
573 * remote forwarding by sending the server just the remote port
574 * number. When a connection comes in, the server tells you which
575 * of its ports was connected to; and _you_ have to remember what
576 * local host:port pair went with that port number.
578 * Hence, in SSH-1 this structure is indexed by destination
579 * host:port pair, whereas in SSH-2 it is indexed by source port.
581 struct ssh_portfwd; /* forward declaration */
583 struct ssh_rportfwd {
584 unsigned sport, dport;
587 struct ssh_portfwd *pfrec;
589 #define free_rportfwd(pf) ( \
590 ((pf) ? (sfree((pf)->sportdesc)) : (void)0 ), sfree(pf) )
593 * Separately to the rportfwd tree (which is for looking up port
594 * open requests from the server), a tree of _these_ structures is
595 * used to keep track of all the currently open port forwardings,
596 * so that we can reconfigure in mid-session if the user requests
600 enum { DESTROY, KEEP, CREATE } status;
602 unsigned sport, dport;
605 struct ssh_rportfwd *remote;
609 #define free_portfwd(pf) ( \
610 ((pf) ? (sfree((pf)->saddr), sfree((pf)->daddr), \
611 sfree((pf)->sserv), sfree((pf)->dserv)) : (void)0 ), sfree(pf) )
614 long length; /* length of `data' actually used */
615 long forcepad; /* SSH-2: force padding to at least this length */
616 int type; /* only used for incoming packets */
617 unsigned long sequence; /* SSH-2 incoming sequence number */
618 unsigned char *data; /* allocated storage */
619 unsigned char *body; /* offset of payload within `data' */
620 long savedpos; /* temporary index into `data' (for strings) */
621 long maxlen; /* amount of storage allocated for `data' */
622 long encrypted_len; /* for SSH-2 total-size counting */
625 * State associated with packet logging
629 struct logblank_t *blanks;
632 static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
633 struct Packet *pktin);
634 static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
635 struct Packet *pktin);
636 static void ssh1_protocol_setup(Ssh ssh);
637 static void ssh2_protocol_setup(Ssh ssh);
638 static void ssh_size(void *handle, int width, int height);
639 static void ssh_special(void *handle, Telnet_Special);
640 static int ssh2_try_send(struct ssh_channel *c);
641 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len);
642 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize);
643 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin);
644 static int ssh_sendbuffer(void *handle);
645 static int ssh_do_close(Ssh ssh, int notify_exit);
646 static unsigned long ssh_pkt_getuint32(struct Packet *pkt);
647 static int ssh2_pkt_getbool(struct Packet *pkt);
648 static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length);
649 static void ssh2_timer(void *ctx, long now);
650 static int do_ssh2_transport(Ssh ssh, void *vin, int inlen,
651 struct Packet *pktin);
653 struct rdpkt1_state_tag {
654 long len, pad, biglen, to_read;
655 unsigned long realcrc, gotcrc;
659 struct Packet *pktin;
662 struct rdpkt2_state_tag {
663 long len, pad, payload, packetlen, maclen;
666 unsigned long incoming_sequence;
667 struct Packet *pktin;
670 typedef void (*handler_fn_t)(Ssh ssh, struct Packet *pktin);
671 typedef void (*chandler_fn_t)(Ssh ssh, struct Packet *pktin, void *ctx);
673 struct queued_handler;
674 struct queued_handler {
676 chandler_fn_t handler;
678 struct queued_handler *next;
682 const struct plug_function_table *fn;
683 /* the above field _must_ be first in the structure */
693 unsigned char session_key[32];
695 int v1_remote_protoflags;
696 int v1_local_protoflags;
697 int agentfwd_enabled;
700 const struct ssh_cipher *cipher;
703 const struct ssh2_cipher *cscipher, *sccipher;
704 void *cs_cipher_ctx, *sc_cipher_ctx;
705 const struct ssh_mac *csmac, *scmac;
706 void *cs_mac_ctx, *sc_mac_ctx;
707 const struct ssh_compress *cscomp, *sccomp;
708 void *cs_comp_ctx, *sc_comp_ctx;
709 const struct ssh_kex *kex;
710 const struct ssh_signkey *hostkey;
711 unsigned char v2_session_id[32];
712 int v2_session_id_len;
718 int echoing, editing;
722 int ospeed, ispeed; /* temporaries */
723 int term_width, term_height;
725 tree234 *channels; /* indexed by local id */
726 struct ssh_channel *mainchan; /* primary session channel */
731 tree234 *rportfwds, *portfwds;
735 SSH_STATE_BEFORE_SIZE,
741 int size_needed, eof_needed;
743 struct Packet **queue;
744 int queuelen, queuesize;
746 unsigned char *deferred_send_data;
747 int deferred_len, deferred_size;
750 * Gross hack: pscp will try to start SFTP but fall back to
751 * scp1 if that fails. This variable is the means by which
752 * scp.c can reach into the SSH code and find out which one it
757 bufchain banner; /* accumulates banners during do_ssh2_authconn */
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_stderr(int trusted, const char *buf, int len)
1048 for (i = 0; i < len; i++)
1049 if (buf[i] != '\r' && (trusted || buf[i] & 0x60))
1050 fputc(buf[i], stderr);
1053 static void c_write(Ssh ssh, const char *buf, int len)
1055 if (flags & FLAG_STDERR)
1056 c_write_stderr(1, buf, len);
1058 from_backend(ssh->frontend, 1, buf, len);
1061 static void c_write_untrusted(Ssh ssh, const char *buf, int len)
1063 if (flags & FLAG_STDERR)
1064 c_write_stderr(0, buf, len);
1066 from_backend_untrusted(ssh->frontend, buf, len);
1069 static void c_write_str(Ssh ssh, const char *buf)
1071 c_write(ssh, buf, strlen(buf));
1074 static void ssh_free_packet(struct Packet *pkt)
1079 static struct Packet *ssh_new_packet(void)
1081 struct Packet *pkt = snew(struct Packet);
1083 pkt->body = pkt->data = NULL;
1085 pkt->logmode = PKTLOG_EMIT;
1093 * Collect incoming data in the incoming packet buffer.
1094 * Decipher and verify the packet when it is completely read.
1095 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
1096 * Update the *data and *datalen variables.
1097 * Return a Packet structure when a packet is completed.
1099 static struct Packet *ssh1_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
1101 struct rdpkt1_state_tag *st = &ssh->rdpkt1_state;
1103 crBegin(ssh->ssh1_rdpkt_crstate);
1105 st->pktin = ssh_new_packet();
1107 st->pktin->type = 0;
1108 st->pktin->length = 0;
1110 for (st->i = st->len = 0; st->i < 4; st->i++) {
1111 while ((*datalen) == 0)
1113 st->len = (st->len << 8) + **data;
1114 (*data)++, (*datalen)--;
1117 st->pad = 8 - (st->len % 8);
1118 st->biglen = st->len + st->pad;
1119 st->pktin->length = st->len - 5;
1121 if (st->biglen < 0) {
1122 bombout(("Extremely large packet length from server suggests"
1123 " data stream corruption"));
1124 ssh_free_packet(st->pktin);
1128 st->pktin->maxlen = st->biglen;
1129 st->pktin->data = snewn(st->biglen + APIEXTRA, unsigned char);
1131 st->to_read = st->biglen;
1132 st->p = st->pktin->data;
1133 while (st->to_read > 0) {
1134 st->chunk = st->to_read;
1135 while ((*datalen) == 0)
1137 if (st->chunk > (*datalen))
1138 st->chunk = (*datalen);
1139 memcpy(st->p, *data, st->chunk);
1141 *datalen -= st->chunk;
1143 st->to_read -= st->chunk;
1146 if (ssh->cipher && detect_attack(ssh->crcda_ctx, st->pktin->data,
1147 st->biglen, NULL)) {
1148 bombout(("Network attack (CRC compensation) detected!"));
1149 ssh_free_packet(st->pktin);
1154 ssh->cipher->decrypt(ssh->v1_cipher_ctx, st->pktin->data, st->biglen);
1156 st->realcrc = crc32_compute(st->pktin->data, st->biglen - 4);
1157 st->gotcrc = GET_32BIT(st->pktin->data + st->biglen - 4);
1158 if (st->gotcrc != st->realcrc) {
1159 bombout(("Incorrect CRC received on packet"));
1160 ssh_free_packet(st->pktin);
1164 st->pktin->body = st->pktin->data + st->pad + 1;
1165 st->pktin->savedpos = 0;
1167 if (ssh->v1_compressing) {
1168 unsigned char *decompblk;
1170 if (!zlib_decompress_block(ssh->sc_comp_ctx,
1171 st->pktin->body - 1, st->pktin->length + 1,
1172 &decompblk, &decomplen)) {
1173 bombout(("Zlib decompression encountered invalid data"));
1174 ssh_free_packet(st->pktin);
1178 if (st->pktin->maxlen < st->pad + decomplen) {
1179 st->pktin->maxlen = st->pad + decomplen;
1180 st->pktin->data = sresize(st->pktin->data,
1181 st->pktin->maxlen + APIEXTRA,
1183 st->pktin->body = st->pktin->data + st->pad + 1;
1186 memcpy(st->pktin->body - 1, decompblk, decomplen);
1188 st->pktin->length = decomplen - 1;
1191 st->pktin->type = st->pktin->body[-1];
1194 * Log incoming packet, possibly omitting sensitive fields.
1198 struct logblank_t blank;
1199 if (ssh->cfg.logomitdata) {
1200 int do_blank = FALSE, blank_prefix = 0;
1201 /* "Session data" packets - omit the data field */
1202 if ((st->pktin->type == SSH1_SMSG_STDOUT_DATA) ||
1203 (st->pktin->type == SSH1_SMSG_STDERR_DATA)) {
1204 do_blank = TRUE; blank_prefix = 0;
1205 } else if (st->pktin->type == SSH1_MSG_CHANNEL_DATA) {
1206 do_blank = TRUE; blank_prefix = 4;
1209 blank.offset = blank_prefix;
1210 blank.len = st->pktin->length;
1211 blank.type = PKTLOG_OMIT;
1215 log_packet(ssh->logctx,
1216 PKT_INCOMING, st->pktin->type,
1217 ssh1_pkt_type(st->pktin->type),
1218 st->pktin->body, st->pktin->length,
1222 crFinish(st->pktin);
1225 static struct Packet *ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
1227 struct rdpkt2_state_tag *st = &ssh->rdpkt2_state;
1229 crBegin(ssh->ssh2_rdpkt_crstate);
1231 st->pktin = ssh_new_packet();
1233 st->pktin->type = 0;
1234 st->pktin->length = 0;
1236 st->cipherblk = ssh->sccipher->blksize;
1239 if (st->cipherblk < 8)
1242 st->pktin->data = snewn(st->cipherblk + APIEXTRA, unsigned char);
1245 * Acquire and decrypt the first block of the packet. This will
1246 * contain the length and padding details.
1248 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
1249 while ((*datalen) == 0)
1251 st->pktin->data[st->i] = *(*data)++;
1256 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1257 st->pktin->data, st->cipherblk);
1260 * Now get the length and padding figures.
1262 st->len = GET_32BIT(st->pktin->data);
1263 st->pad = st->pktin->data[4];
1266 * _Completely_ silly lengths should be stomped on before they
1267 * do us any more damage.
1269 if (st->len < 0 || st->len > 35000 || st->pad < 4 ||
1270 st->len - st->pad < 1 || (st->len + 4) % st->cipherblk != 0) {
1271 bombout(("Incoming packet was garbled on decryption"));
1272 ssh_free_packet(st->pktin);
1277 * This enables us to deduce the payload length.
1279 st->payload = st->len - st->pad - 1;
1281 st->pktin->length = st->payload + 5;
1284 * So now we can work out the total packet length.
1286 st->packetlen = st->len + 4;
1287 st->maclen = ssh->scmac ? ssh->scmac->len : 0;
1290 * Allocate memory for the rest of the packet.
1292 st->pktin->maxlen = st->packetlen + st->maclen;
1293 st->pktin->data = sresize(st->pktin->data,
1294 st->pktin->maxlen + APIEXTRA,
1298 * Read and decrypt the remainder of the packet.
1300 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
1302 while ((*datalen) == 0)
1304 st->pktin->data[st->i] = *(*data)++;
1307 /* Decrypt everything _except_ the MAC. */
1309 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1310 st->pktin->data + st->cipherblk,
1311 st->packetlen - st->cipherblk);
1313 st->pktin->encrypted_len = st->packetlen;
1319 && !ssh->scmac->verify(ssh->sc_mac_ctx, st->pktin->data, st->len + 4,
1320 st->incoming_sequence)) {
1321 bombout(("Incorrect MAC received on packet"));
1322 ssh_free_packet(st->pktin);
1326 st->pktin->sequence = st->incoming_sequence++;
1329 * Decompress packet payload.
1332 unsigned char *newpayload;
1335 ssh->sccomp->decompress(ssh->sc_comp_ctx,
1336 st->pktin->data + 5, st->pktin->length - 5,
1337 &newpayload, &newlen)) {
1338 if (st->pktin->maxlen < newlen + 5) {
1339 st->pktin->maxlen = newlen + 5;
1340 st->pktin->data = sresize(st->pktin->data,
1341 st->pktin->maxlen + APIEXTRA,
1344 st->pktin->length = 5 + newlen;
1345 memcpy(st->pktin->data + 5, newpayload, newlen);
1350 st->pktin->savedpos = 6;
1351 st->pktin->body = st->pktin->data;
1352 st->pktin->type = st->pktin->data[5];
1355 * Log incoming packet, possibly omitting sensitive fields.
1359 struct logblank_t blank;
1360 if (ssh->cfg.logomitdata) {
1361 int do_blank = FALSE, blank_prefix = 0;
1362 /* "Session data" packets - omit the data field */
1363 if (st->pktin->type == SSH2_MSG_CHANNEL_DATA) {
1364 do_blank = TRUE; blank_prefix = 4;
1365 } else if (st->pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
1366 do_blank = TRUE; blank_prefix = 8;
1369 blank.offset = blank_prefix;
1370 blank.len = (st->pktin->length-6) - blank_prefix;
1371 blank.type = PKTLOG_OMIT;
1375 log_packet(ssh->logctx, PKT_INCOMING, st->pktin->type,
1376 ssh2_pkt_type(ssh->pkt_ctx, st->pktin->type),
1377 st->pktin->data+6, st->pktin->length-6,
1381 crFinish(st->pktin);
1384 static int s_wrpkt_prepare(Ssh ssh, struct Packet *pkt, int *offset_p)
1386 int pad, biglen, i, pktoffs;
1390 * XXX various versions of SC (including 8.8.4) screw up the
1391 * register allocation in this function and use the same register
1392 * (D6) for len and as a temporary, with predictable results. The
1393 * following sledgehammer prevents this.
1400 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[12],
1401 ssh1_pkt_type(pkt->data[12]),
1402 pkt->body, pkt->length - (pkt->body - pkt->data),
1403 pkt->nblanks, pkt->blanks);
1404 sfree(pkt->blanks); pkt->blanks = NULL;
1407 if (ssh->v1_compressing) {
1408 unsigned char *compblk;
1410 zlib_compress_block(ssh->cs_comp_ctx,
1411 pkt->data + 12, pkt->length - 12,
1412 &compblk, &complen);
1413 memcpy(pkt->data + 12, compblk, complen);
1415 pkt->length = complen + 12;
1418 ssh_pkt_ensure(pkt, pkt->length + 4); /* space for CRC */
1420 len = pkt->length - 4 - 8; /* len(type+data+CRC) */
1421 pad = 8 - (len % 8);
1423 biglen = len + pad; /* len(padding+type+data+CRC) */
1425 for (i = pktoffs; i < 4+8; i++)
1426 pkt->data[i] = random_byte();
1427 crc = crc32_compute(pkt->data + pktoffs + 4, biglen - 4); /* all ex len */
1428 PUT_32BIT(pkt->data + pktoffs + 4 + biglen - 4, crc);
1429 PUT_32BIT(pkt->data + pktoffs, len);
1432 ssh->cipher->encrypt(ssh->v1_cipher_ctx,
1433 pkt->data + pktoffs + 4, biglen);
1435 if (offset_p) *offset_p = pktoffs;
1436 return biglen + 4; /* len(length+padding+type+data+CRC) */
1439 static void s_wrpkt(Ssh ssh, struct Packet *pkt)
1441 int len, backlog, offset;
1442 len = s_wrpkt_prepare(ssh, pkt, &offset);
1443 backlog = sk_write(ssh->s, (char *)pkt->data + offset, len);
1444 if (backlog > SSH_MAX_BACKLOG)
1445 ssh_throttle_all(ssh, 1, backlog);
1446 ssh_free_packet(pkt);
1449 static void s_wrpkt_defer(Ssh ssh, struct Packet *pkt)
1452 len = s_wrpkt_prepare(ssh, pkt, &offset);
1453 if (ssh->deferred_len + len > ssh->deferred_size) {
1454 ssh->deferred_size = ssh->deferred_len + len + 128;
1455 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1459 memcpy(ssh->deferred_send_data + ssh->deferred_len,
1460 pkt->data + offset, len);
1461 ssh->deferred_len += len;
1462 ssh_free_packet(pkt);
1466 * Construct a SSH-1 packet with the specified contents.
1467 * (This all-at-once interface used to be the only one, but now SSH-1
1468 * packets can also be constructed incrementally.)
1470 static struct Packet *construct_packet(Ssh ssh, int pkttype, va_list ap)
1476 pkt = ssh1_pkt_init(pkttype);
1478 while ((argtype = va_arg(ap, int)) != PKT_END) {
1479 unsigned char *argp, argchar;
1480 unsigned long argint;
1483 /* Actual fields in the packet */
1485 argint = va_arg(ap, int);
1486 ssh_pkt_adduint32(pkt, argint);
1489 argchar = (unsigned char) va_arg(ap, int);
1490 ssh_pkt_addbyte(pkt, argchar);
1493 argp = va_arg(ap, unsigned char *);
1494 arglen = va_arg(ap, int);
1495 ssh_pkt_adddata(pkt, argp, arglen);
1498 argp = va_arg(ap, unsigned char *);
1499 ssh_pkt_addstring(pkt, argp);
1502 bn = va_arg(ap, Bignum);
1503 ssh1_pkt_addmp(pkt, bn);
1505 /* Tokens for modifications to packet logging */
1507 dont_log_password(ssh, pkt, PKTLOG_BLANK);
1510 dont_log_data(ssh, pkt, PKTLOG_OMIT);
1513 end_log_omission(ssh, pkt);
1521 static void send_packet(Ssh ssh, int pkttype, ...)
1525 va_start(ap, pkttype);
1526 pkt = construct_packet(ssh, pkttype, ap);
1531 static void defer_packet(Ssh ssh, int pkttype, ...)
1535 va_start(ap, pkttype);
1536 pkt = construct_packet(ssh, pkttype, ap);
1538 s_wrpkt_defer(ssh, pkt);
1541 static int ssh_versioncmp(char *a, char *b)
1544 unsigned long av, bv;
1546 av = strtoul(a, &ae, 10);
1547 bv = strtoul(b, &be, 10);
1549 return (av < bv ? -1 : +1);
1554 av = strtoul(ae, &ae, 10);
1555 bv = strtoul(be, &be, 10);
1557 return (av < bv ? -1 : +1);
1562 * Utility routines for putting an SSH-protocol `string' and
1563 * `uint32' into a hash state.
1565 static void hash_string(const struct ssh_hash *h, void *s, void *str, int len)
1567 unsigned char lenblk[4];
1568 PUT_32BIT(lenblk, len);
1569 h->bytes(s, lenblk, 4);
1570 h->bytes(s, str, len);
1573 static void hash_uint32(const struct ssh_hash *h, void *s, unsigned i)
1575 unsigned char intblk[4];
1576 PUT_32BIT(intblk, i);
1577 h->bytes(s, intblk, 4);
1581 * Packet construction functions. Mostly shared between SSH-1 and SSH-2.
1583 static void ssh_pkt_ensure(struct Packet *pkt, int length)
1585 if (pkt->maxlen < length) {
1586 unsigned char *body = pkt->body;
1587 int offset = body ? body - pkt->data : 0;
1588 pkt->maxlen = length + 256;
1589 pkt->data = sresize(pkt->data, pkt->maxlen + APIEXTRA, unsigned char);
1590 if (body) pkt->body = pkt->data + offset;
1593 static void ssh_pkt_adddata(struct Packet *pkt, void *data, int len)
1595 if (pkt->logmode != PKTLOG_EMIT) {
1597 pkt->blanks = sresize(pkt->blanks, pkt->nblanks, struct logblank_t);
1599 pkt->blanks[pkt->nblanks-1].offset = pkt->length -
1600 (pkt->body - pkt->data);
1601 pkt->blanks[pkt->nblanks-1].len = len;
1602 pkt->blanks[pkt->nblanks-1].type = pkt->logmode;
1605 ssh_pkt_ensure(pkt, pkt->length);
1606 memcpy(pkt->data + pkt->length - len, data, len);
1608 static void ssh_pkt_addbyte(struct Packet *pkt, unsigned char byte)
1610 ssh_pkt_adddata(pkt, &byte, 1);
1612 static void ssh2_pkt_addbool(struct Packet *pkt, unsigned char value)
1614 ssh_pkt_adddata(pkt, &value, 1);
1616 static void ssh_pkt_adduint32(struct Packet *pkt, unsigned long value)
1619 PUT_32BIT(x, value);
1620 ssh_pkt_adddata(pkt, x, 4);
1622 static void ssh_pkt_addstring_start(struct Packet *pkt)
1624 ssh_pkt_adduint32(pkt, 0);
1625 pkt->savedpos = pkt->length;
1627 static void ssh_pkt_addstring_str(struct Packet *pkt, char *data)
1629 ssh_pkt_adddata(pkt, data, strlen(data));
1630 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
1632 static void ssh_pkt_addstring_data(struct Packet *pkt, char *data, int len)
1634 ssh_pkt_adddata(pkt, data, len);
1635 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
1637 static void ssh_pkt_addstring(struct Packet *pkt, char *data)
1639 ssh_pkt_addstring_start(pkt);
1640 ssh_pkt_addstring_str(pkt, data);
1642 static void ssh1_pkt_addmp(struct Packet *pkt, Bignum b)
1644 int len = ssh1_bignum_length(b);
1645 unsigned char *data = snewn(len, char);
1646 (void) ssh1_write_bignum(data, b);
1647 ssh_pkt_adddata(pkt, data, len);
1650 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len)
1653 int i, n = (bignum_bitcount(b) + 7) / 8;
1654 p = snewn(n + 1, unsigned char);
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();
1697 pkt->length = 5; /* space for packet length + padding length */
1699 ssh_pkt_addbyte(pkt, (unsigned char) pkt_type);
1700 pkt->body = pkt->data + pkt->length; /* after packet type */
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().
1801 * When using a CBC-mode cipher, it's necessary to ensure that an
1802 * attacker can't provide data to be encrypted using an IV that they
1803 * know. We ensure this by prefixing each packet that might contain
1804 * user data with an SSH_MSG_IGNORE. This is done using the deferral
1805 * mechanism, so in this case send_noqueue() ends up redirecting to
1806 * defer_noqueue(). If you don't like this inefficiency, don't use
1810 static void ssh2_pkt_defer_noqueue(Ssh, struct Packet *, int);
1811 static void ssh_pkt_defersend(Ssh);
1814 * Send an SSH-2 packet immediately, without queuing or deferring.
1816 static void ssh2_pkt_send_noqueue(Ssh ssh, struct Packet *pkt)
1820 if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC)) {
1821 /* We need to send two packets, so use the deferral mechanism. */
1822 ssh2_pkt_defer_noqueue(ssh, pkt, FALSE);
1823 ssh_pkt_defersend(ssh);
1826 len = ssh2_pkt_construct(ssh, pkt);
1827 backlog = sk_write(ssh->s, (char *)pkt->data, len);
1828 if (backlog > SSH_MAX_BACKLOG)
1829 ssh_throttle_all(ssh, 1, backlog);
1831 ssh->outgoing_data_size += pkt->encrypted_len;
1832 if (!ssh->kex_in_progress &&
1833 ssh->max_data_size != 0 &&
1834 ssh->outgoing_data_size > ssh->max_data_size)
1835 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
1837 ssh_free_packet(pkt);
1841 * Defer an SSH-2 packet.
1843 static void ssh2_pkt_defer_noqueue(Ssh ssh, struct Packet *pkt, int noignore)
1846 if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC) &&
1847 ssh->deferred_len == 0 && !noignore) {
1849 * Interpose an SSH_MSG_IGNORE to ensure that user data don't
1850 * get encrypted with a known IV.
1852 struct Packet *ipkt = ssh2_pkt_init(SSH2_MSG_IGNORE);
1853 ssh2_pkt_defer_noqueue(ssh, ipkt, TRUE);
1855 len = ssh2_pkt_construct(ssh, pkt);
1856 if (ssh->deferred_len + len > ssh->deferred_size) {
1857 ssh->deferred_size = ssh->deferred_len + len + 128;
1858 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1862 memcpy(ssh->deferred_send_data + ssh->deferred_len, pkt->data, len);
1863 ssh->deferred_len += len;
1864 ssh->deferred_data_size += pkt->encrypted_len;
1865 ssh_free_packet(pkt);
1869 * Queue an SSH-2 packet.
1871 static void ssh2_pkt_queue(Ssh ssh, struct Packet *pkt)
1873 assert(ssh->queueing);
1875 if (ssh->queuelen >= ssh->queuesize) {
1876 ssh->queuesize = ssh->queuelen + 32;
1877 ssh->queue = sresize(ssh->queue, ssh->queuesize, struct Packet *);
1880 ssh->queue[ssh->queuelen++] = pkt;
1884 * Either queue or send a packet, depending on whether queueing is
1887 static void ssh2_pkt_send(Ssh ssh, struct Packet *pkt)
1890 ssh2_pkt_queue(ssh, pkt);
1892 ssh2_pkt_send_noqueue(ssh, pkt);
1897 * Either queue or defer a packet, depending on whether queueing is
1900 static void ssh2_pkt_defer(Ssh ssh, struct Packet *pkt)
1903 ssh2_pkt_queue(ssh, pkt);
1905 ssh2_pkt_defer_noqueue(ssh, pkt, FALSE);
1910 * Send the whole deferred data block constructed by
1911 * ssh2_pkt_defer() or SSH-1's defer_packet().
1913 * The expected use of the defer mechanism is that you call
1914 * ssh2_pkt_defer() a few times, then call ssh_pkt_defersend(). If
1915 * not currently queueing, this simply sets up deferred_send_data
1916 * and then sends it. If we _are_ currently queueing, the calls to
1917 * ssh2_pkt_defer() put the deferred packets on to the queue
1918 * instead, and therefore ssh_pkt_defersend() has no deferred data
1919 * to send. Hence, there's no need to make it conditional on
1922 static void ssh_pkt_defersend(Ssh ssh)
1925 backlog = sk_write(ssh->s, (char *)ssh->deferred_send_data,
1927 ssh->deferred_len = ssh->deferred_size = 0;
1928 sfree(ssh->deferred_send_data);
1929 ssh->deferred_send_data = NULL;
1930 if (backlog > SSH_MAX_BACKLOG)
1931 ssh_throttle_all(ssh, 1, backlog);
1933 ssh->outgoing_data_size += ssh->deferred_data_size;
1934 if (!ssh->kex_in_progress &&
1935 ssh->max_data_size != 0 &&
1936 ssh->outgoing_data_size > ssh->max_data_size)
1937 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
1938 ssh->deferred_data_size = 0;
1942 * Send all queued SSH-2 packets. We send them by means of
1943 * ssh2_pkt_defer_noqueue(), in case they included a pair of
1944 * packets that needed to be lumped together.
1946 static void ssh2_pkt_queuesend(Ssh ssh)
1950 assert(!ssh->queueing);
1952 for (i = 0; i < ssh->queuelen; i++)
1953 ssh2_pkt_defer_noqueue(ssh, ssh->queue[i], FALSE);
1956 ssh_pkt_defersend(ssh);
1960 void bndebug(char *string, Bignum b)
1964 p = ssh2_mpint_fmt(b, &len);
1965 debug(("%s", string));
1966 for (i = 0; i < len; i++)
1967 debug((" %02x", p[i]));
1973 static void hash_mpint(const struct ssh_hash *h, void *s, Bignum b)
1977 p = ssh2_mpint_fmt(b, &len);
1978 hash_string(h, s, p, len);
1983 * Packet decode functions for both SSH-1 and SSH-2.
1985 static unsigned long ssh_pkt_getuint32(struct Packet *pkt)
1987 unsigned long value;
1988 if (pkt->length - pkt->savedpos < 4)
1989 return 0; /* arrgh, no way to decline (FIXME?) */
1990 value = GET_32BIT(pkt->body + pkt->savedpos);
1994 static int ssh2_pkt_getbool(struct Packet *pkt)
1996 unsigned long value;
1997 if (pkt->length - pkt->savedpos < 1)
1998 return 0; /* arrgh, no way to decline (FIXME?) */
1999 value = pkt->body[pkt->savedpos] != 0;
2003 static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length)
2008 if (pkt->length - pkt->savedpos < 4)
2010 len = GET_32BIT(pkt->body + pkt->savedpos);
2015 if (pkt->length - pkt->savedpos < *length)
2017 *p = (char *)(pkt->body + pkt->savedpos);
2018 pkt->savedpos += *length;
2020 static void *ssh_pkt_getdata(struct Packet *pkt, int length)
2022 if (pkt->length - pkt->savedpos < length)
2024 pkt->savedpos += length;
2025 return pkt->body + (pkt->savedpos - length);
2027 static int ssh1_pkt_getrsakey(struct Packet *pkt, struct RSAKey *key,
2028 unsigned char **keystr)
2032 j = makekey(pkt->body + pkt->savedpos,
2033 pkt->length - pkt->savedpos,
2040 assert(pkt->savedpos < pkt->length);
2044 static Bignum ssh1_pkt_getmp(struct Packet *pkt)
2049 j = ssh1_read_bignum(pkt->body + pkt->savedpos,
2050 pkt->length - pkt->savedpos, &b);
2058 static Bignum ssh2_pkt_getmp(struct Packet *pkt)
2064 ssh_pkt_getstring(pkt, &p, &length);
2069 b = bignum_from_bytes((unsigned char *)p, length);
2074 * Helper function to add an SSH-2 signature blob to a packet.
2075 * Expects to be shown the public key blob as well as the signature
2076 * blob. Normally works just like ssh2_pkt_addstring, but will
2077 * fiddle with the signature packet if necessary for
2078 * BUG_SSH2_RSA_PADDING.
2080 static void ssh2_add_sigblob(Ssh ssh, struct Packet *pkt,
2081 void *pkblob_v, int pkblob_len,
2082 void *sigblob_v, int sigblob_len)
2084 unsigned char *pkblob = (unsigned char *)pkblob_v;
2085 unsigned char *sigblob = (unsigned char *)sigblob_v;
2087 /* dmemdump(pkblob, pkblob_len); */
2088 /* dmemdump(sigblob, sigblob_len); */
2091 * See if this is in fact an ssh-rsa signature and a buggy
2092 * server; otherwise we can just do this the easy way.
2094 if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) &&
2095 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
2096 int pos, len, siglen;
2099 * Find the byte length of the modulus.
2102 pos = 4+7; /* skip over "ssh-rsa" */
2103 pos += 4 + GET_32BIT(pkblob+pos); /* skip over exponent */
2104 len = GET_32BIT(pkblob+pos); /* find length of modulus */
2105 pos += 4; /* find modulus itself */
2106 while (len > 0 && pkblob[pos] == 0)
2108 /* debug(("modulus length is %d\n", len)); */
2111 * Now find the signature integer.
2113 pos = 4+7; /* skip over "ssh-rsa" */
2114 siglen = GET_32BIT(sigblob+pos);
2115 /* debug(("signature length is %d\n", siglen)); */
2117 if (len != siglen) {
2118 unsigned char newlen[4];
2119 ssh2_pkt_addstring_start(pkt);
2120 ssh2_pkt_addstring_data(pkt, (char *)sigblob, pos);
2121 /* dmemdump(sigblob, pos); */
2122 pos += 4; /* point to start of actual sig */
2123 PUT_32BIT(newlen, len);
2124 ssh2_pkt_addstring_data(pkt, (char *)newlen, 4);
2125 /* dmemdump(newlen, 4); */
2127 while (len-- > siglen) {
2128 ssh2_pkt_addstring_data(pkt, (char *)newlen, 1);
2129 /* dmemdump(newlen, 1); */
2131 ssh2_pkt_addstring_data(pkt, (char *)(sigblob+pos), siglen);
2132 /* dmemdump(sigblob+pos, siglen); */
2136 /* Otherwise fall through and do it the easy way. */
2139 ssh2_pkt_addstring_start(pkt);
2140 ssh2_pkt_addstring_data(pkt, (char *)sigblob, sigblob_len);
2144 * Examine the remote side's version string and compare it against
2145 * a list of known buggy implementations.
2147 static void ssh_detect_bugs(Ssh ssh, char *vstring)
2149 char *imp; /* pointer to implementation part */
2151 imp += strcspn(imp, "-");
2153 imp += strcspn(imp, "-");
2156 ssh->remote_bugs = 0;
2158 if (ssh->cfg.sshbug_ignore1 == FORCE_ON ||
2159 (ssh->cfg.sshbug_ignore1 == AUTO &&
2160 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
2161 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
2162 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25") ||
2163 !strcmp(imp, "OSU_1.4alpha3") || !strcmp(imp, "OSU_1.5alpha4")))) {
2165 * These versions don't support SSH1_MSG_IGNORE, so we have
2166 * to use a different defence against password length
2169 ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
2170 logevent("We believe remote version has SSH-1 ignore bug");
2173 if (ssh->cfg.sshbug_plainpw1 == FORCE_ON ||
2174 (ssh->cfg.sshbug_plainpw1 == AUTO &&
2175 (!strcmp(imp, "Cisco-1.25") || !strcmp(imp, "OSU_1.4alpha3")))) {
2177 * These versions need a plain password sent; they can't
2178 * handle having a null and a random length of data after
2181 ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
2182 logevent("We believe remote version needs a plain SSH-1 password");
2185 if (ssh->cfg.sshbug_rsa1 == FORCE_ON ||
2186 (ssh->cfg.sshbug_rsa1 == AUTO &&
2187 (!strcmp(imp, "Cisco-1.25")))) {
2189 * These versions apparently have no clue whatever about
2190 * RSA authentication and will panic and die if they see
2191 * an AUTH_RSA message.
2193 ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
2194 logevent("We believe remote version can't handle SSH-1 RSA authentication");
2197 if (ssh->cfg.sshbug_hmac2 == FORCE_ON ||
2198 (ssh->cfg.sshbug_hmac2 == AUTO &&
2199 !wc_match("* VShell", imp) &&
2200 (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) ||
2201 wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) ||
2202 wc_match("2.1 *", imp)))) {
2204 * These versions have the HMAC bug.
2206 ssh->remote_bugs |= BUG_SSH2_HMAC;
2207 logevent("We believe remote version has SSH-2 HMAC bug");
2210 if (ssh->cfg.sshbug_derivekey2 == FORCE_ON ||
2211 (ssh->cfg.sshbug_derivekey2 == AUTO &&
2212 !wc_match("* VShell", imp) &&
2213 (wc_match("2.0.0*", imp) || wc_match("2.0.10*", imp) ))) {
2215 * These versions have the key-derivation bug (failing to
2216 * include the literal shared secret in the hashes that
2217 * generate the keys).
2219 ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
2220 logevent("We believe remote version has SSH-2 key-derivation bug");
2223 if (ssh->cfg.sshbug_rsapad2 == FORCE_ON ||
2224 (ssh->cfg.sshbug_rsapad2 == AUTO &&
2225 (wc_match("OpenSSH_2.[5-9]*", imp) ||
2226 wc_match("OpenSSH_3.[0-2]*", imp)))) {
2228 * These versions have the SSH-2 RSA padding bug.
2230 ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
2231 logevent("We believe remote version has SSH-2 RSA padding bug");
2234 if (ssh->cfg.sshbug_pksessid2 == FORCE_ON ||
2235 (ssh->cfg.sshbug_pksessid2 == AUTO &&
2236 wc_match("OpenSSH_2.[0-2]*", imp))) {
2238 * These versions have the SSH-2 session-ID bug in
2239 * public-key authentication.
2241 ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID;
2242 logevent("We believe remote version has SSH-2 public-key-session-ID bug");
2245 if (ssh->cfg.sshbug_rekey2 == FORCE_ON ||
2246 (ssh->cfg.sshbug_rekey2 == AUTO &&
2247 (wc_match("DigiSSH_2.0", imp) ||
2248 wc_match("OpenSSH_2.[0-4]*", imp) ||
2249 wc_match("OpenSSH_2.5.[0-3]*", imp) ||
2250 wc_match("Sun_SSH_1.0", imp) ||
2251 wc_match("Sun_SSH_1.0.1", imp) ||
2252 /* All versions <= 1.2.6 (they changed their format in 1.2.7) */
2253 wc_match("WeOnlyDo-*", imp)))) {
2255 * These versions have the SSH-2 rekey bug.
2257 ssh->remote_bugs |= BUG_SSH2_REKEY;
2258 logevent("We believe remote version has SSH-2 rekey bug");
2263 * The `software version' part of an SSH version string is required
2264 * to contain no spaces or minus signs.
2266 static void ssh_fix_verstring(char *str)
2268 /* Eat "SSH-<protoversion>-". */
2269 assert(*str == 'S'); str++;
2270 assert(*str == 'S'); str++;
2271 assert(*str == 'H'); str++;
2272 assert(*str == '-'); str++;
2273 while (*str && *str != '-') str++;
2274 assert(*str == '-'); str++;
2276 /* Convert minus signs and spaces in the remaining string into
2279 if (*str == '-' || *str == ' ')
2285 static int do_ssh_init(Ssh ssh, unsigned char c)
2287 struct do_ssh_init_state {
2295 crState(do_ssh_init_state);
2297 crBegin(ssh->do_ssh_init_crstate);
2299 /* Search for a line beginning with the string "SSH-" in the input. */
2301 if (c != 'S') goto no;
2303 if (c != 'S') goto no;
2305 if (c != 'H') goto no;
2307 if (c != '-') goto no;
2316 s->vstring = snewn(s->vstrsize, char);
2317 strcpy(s->vstring, "SSH-");
2321 crReturn(1); /* get another char */
2322 if (s->vslen >= s->vstrsize - 1) {
2324 s->vstring = sresize(s->vstring, s->vstrsize, char);
2326 s->vstring[s->vslen++] = c;
2329 s->version[s->i] = '\0';
2331 } else if (s->i < sizeof(s->version) - 1)
2332 s->version[s->i++] = c;
2333 } else if (c == '\012')
2337 ssh->agentfwd_enabled = FALSE;
2338 ssh->rdpkt2_state.incoming_sequence = 0;
2340 s->vstring[s->vslen] = 0;
2341 s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */
2342 logeventf(ssh, "Server version: %s", s->vstring);
2343 ssh_detect_bugs(ssh, s->vstring);
2346 * Decide which SSH protocol version to support.
2349 /* Anything strictly below "2.0" means protocol 1 is supported. */
2350 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
2351 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
2352 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
2354 if (ssh->cfg.sshprot == 0 && !s->proto1) {
2355 bombout(("SSH protocol version 1 required by user but not provided by server"));
2358 if (ssh->cfg.sshprot == 3 && !s->proto2) {
2359 bombout(("SSH protocol version 2 required by user but not provided by server"));
2366 if (s->proto2 && (ssh->cfg.sshprot >= 2 || !s->proto1)) {
2368 * Construct a v2 version string.
2370 verstring = dupprintf("SSH-2.0-%s\015\012", sshver);
2374 * Construct a v1 version string.
2376 verstring = dupprintf("SSH-%s-%s\012",
2377 (ssh_versioncmp(s->version, "1.5") <= 0 ?
2378 s->version : "1.5"),
2383 ssh_fix_verstring(verstring);
2385 if (ssh->version == 2) {
2388 * Hash our version string and their version string.
2390 len = strcspn(verstring, "\015\012");
2391 ssh->v_c = snewn(len + 1, char);
2392 memcpy(ssh->v_c, verstring, len);
2394 len = strcspn(s->vstring, "\015\012");
2395 ssh->v_s = snewn(len + 1, char);
2396 memcpy(ssh->v_s, s->vstring, len);
2400 * Initialise SSH-2 protocol.
2402 ssh->protocol = ssh2_protocol;
2403 ssh2_protocol_setup(ssh);
2404 ssh->s_rdpkt = ssh2_rdpkt;
2407 * Initialise SSH-1 protocol.
2409 ssh->protocol = ssh1_protocol;
2410 ssh1_protocol_setup(ssh);
2411 ssh->s_rdpkt = ssh1_rdpkt;
2413 logeventf(ssh, "We claim version: %.*s",
2414 strcspn(verstring, "\015\012"), verstring);
2415 sk_write(ssh->s, verstring, strlen(verstring));
2417 if (ssh->version == 2)
2418 do_ssh2_transport(ssh, NULL, -1, NULL);
2421 logeventf(ssh, "Using SSH protocol version %d", ssh->version);
2423 update_specials_menu(ssh->frontend);
2424 ssh->state = SSH_STATE_BEFORE_SIZE;
2425 ssh->pinger = pinger_new(&ssh->cfg, &ssh_backend, ssh);
2432 static void ssh_process_incoming_data(Ssh ssh,
2433 unsigned char **data, int *datalen)
2435 struct Packet *pktin = ssh->s_rdpkt(ssh, data, datalen);
2437 ssh->protocol(ssh, NULL, 0, pktin);
2438 ssh_free_packet(pktin);
2442 static void ssh_queue_incoming_data(Ssh ssh,
2443 unsigned char **data, int *datalen)
2445 bufchain_add(&ssh->queued_incoming_data, *data, *datalen);
2450 static void ssh_process_queued_incoming_data(Ssh ssh)
2453 unsigned char *data;
2456 while (!ssh->frozen && bufchain_size(&ssh->queued_incoming_data)) {
2457 bufchain_prefix(&ssh->queued_incoming_data, &vdata, &len);
2461 while (!ssh->frozen && len > 0)
2462 ssh_process_incoming_data(ssh, &data, &len);
2465 bufchain_consume(&ssh->queued_incoming_data, origlen - len);
2469 static void ssh_set_frozen(Ssh ssh, int frozen)
2472 sk_set_frozen(ssh->s, frozen);
2473 ssh->frozen = frozen;
2476 static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
2478 crBegin(ssh->ssh_gotdata_crstate);
2481 * To begin with, feed the characters one by one to the
2482 * protocol initialisation / selection function do_ssh_init().
2483 * When that returns 0, we're done with the initial greeting
2484 * exchange and can move on to packet discipline.
2487 int ret; /* need not be kept across crReturn */
2489 crReturnV; /* more data please */
2490 ret = do_ssh_init(ssh, *data);
2498 * We emerge from that loop when the initial negotiation is
2499 * over and we have selected an s_rdpkt function. Now pass
2500 * everything to s_rdpkt, and then pass the resulting packets
2501 * to the proper protocol handler.
2505 while (bufchain_size(&ssh->queued_incoming_data) > 0 || datalen > 0) {
2507 ssh_queue_incoming_data(ssh, &data, &datalen);
2508 /* This uses up all data and cannot cause anything interesting
2509 * to happen; indeed, for anything to happen at all, we must
2510 * return, so break out. */
2512 } else if (bufchain_size(&ssh->queued_incoming_data) > 0) {
2513 /* This uses up some or all data, and may freeze the
2515 ssh_process_queued_incoming_data(ssh);
2517 /* This uses up some or all data, and may freeze the
2519 ssh_process_incoming_data(ssh, &data, &datalen);
2521 /* FIXME this is probably EBW. */
2522 if (ssh->state == SSH_STATE_CLOSED)
2525 /* We're out of data. Go and get some more. */
2531 static int ssh_do_close(Ssh ssh, int notify_exit)
2534 struct ssh_channel *c;
2536 ssh->state = SSH_STATE_CLOSED;
2537 expire_timer_context(ssh);
2542 notify_remote_exit(ssh->frontend);
2547 * Now we must shut down any port- and X-forwarded channels going
2548 * through this connection.
2550 if (ssh->channels) {
2551 while (NULL != (c = index234(ssh->channels, 0))) {
2554 x11_close(c->u.x11.s);
2557 pfd_close(c->u.pfd.s);
2560 del234(ssh->channels, c); /* moving next one to index 0 */
2561 if (ssh->version == 2)
2562 bufchain_clear(&c->v.v2.outbuffer);
2567 * Go through port-forwardings, and close any associated
2568 * listening sockets.
2570 if (ssh->portfwds) {
2571 struct ssh_portfwd *pf;
2572 while (NULL != (pf = index234(ssh->portfwds, 0))) {
2573 /* Dispose of any listening socket. */
2575 pfd_terminate(pf->local);
2576 del234(ssh->portfwds, pf); /* moving next one to index 0 */
2584 static void ssh_log(Plug plug, int type, SockAddr addr, int port,
2585 const char *error_msg, int error_code)
2587 Ssh ssh = (Ssh) plug;
2588 char addrbuf[256], *msg;
2590 sk_getaddr(addr, addrbuf, lenof(addrbuf));
2593 msg = dupprintf("Connecting to %s port %d", addrbuf, port);
2595 msg = dupprintf("Failed to connect to %s: %s", addrbuf, error_msg);
2601 static int ssh_closing(Plug plug, const char *error_msg, int error_code,
2604 Ssh ssh = (Ssh) plug;
2605 int need_notify = ssh_do_close(ssh, FALSE);
2608 if (!ssh->close_expected)
2609 error_msg = "Server unexpectedly closed network connection";
2611 error_msg = "Server closed network connection";
2615 notify_remote_exit(ssh->frontend);
2618 logevent(error_msg);
2619 if (!ssh->close_expected || !ssh->clean_exit)
2620 connection_fatal(ssh->frontend, "%s", error_msg);
2624 static int ssh_receive(Plug plug, int urgent, char *data, int len)
2626 Ssh ssh = (Ssh) plug;
2627 ssh_gotdata(ssh, (unsigned char *)data, len);
2628 if (ssh->state == SSH_STATE_CLOSED) {
2629 ssh_do_close(ssh, TRUE);
2635 static void ssh_sent(Plug plug, int bufsize)
2637 Ssh ssh = (Ssh) plug;
2639 * If the send backlog on the SSH socket itself clears, we
2640 * should unthrottle the whole world if it was throttled.
2642 if (bufsize < SSH_MAX_BACKLOG)
2643 ssh_throttle_all(ssh, 0, bufsize);
2647 * Connect to specified host and port.
2648 * Returns an error message, or NULL on success.
2649 * Also places the canonical host name into `realhost'. It must be
2650 * freed by the caller.
2652 static const char *connect_to_host(Ssh ssh, char *host, int port,
2653 char **realhost, int nodelay, int keepalive)
2655 static const struct plug_function_table fn_table = {
2666 ssh->savedhost = snewn(1 + strlen(host), char);
2667 strcpy(ssh->savedhost, host);
2670 port = 22; /* default ssh port */
2671 ssh->savedport = port;
2676 logeventf(ssh, "Looking up host \"%s\"%s", host,
2677 (ssh->cfg.addressfamily == ADDRTYPE_IPV4 ? " (IPv4)" :
2678 (ssh->cfg.addressfamily == ADDRTYPE_IPV6 ? " (IPv6)" : "")));
2679 addr = name_lookup(host, port, realhost, &ssh->cfg,
2680 ssh->cfg.addressfamily);
2681 if ((err = sk_addr_error(addr)) != NULL) {
2689 ssh->fn = &fn_table;
2690 ssh->s = new_connection(addr, *realhost, port,
2691 0, 1, nodelay, keepalive, (Plug) ssh, &ssh->cfg);
2692 if ((err = sk_socket_error(ssh->s)) != NULL) {
2694 notify_remote_exit(ssh->frontend);
2702 * Throttle or unthrottle the SSH connection.
2704 static void ssh1_throttle(Ssh ssh, int adjust)
2706 int old_count = ssh->v1_throttle_count;
2707 ssh->v1_throttle_count += adjust;
2708 assert(ssh->v1_throttle_count >= 0);
2709 if (ssh->v1_throttle_count && !old_count) {
2710 ssh_set_frozen(ssh, 1);
2711 } else if (!ssh->v1_throttle_count && old_count) {
2712 ssh_set_frozen(ssh, 0);
2717 * Throttle or unthrottle _all_ local data streams (for when sends
2718 * on the SSH connection itself back up).
2720 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
2723 struct ssh_channel *c;
2725 if (enable == ssh->throttled_all)
2727 ssh->throttled_all = enable;
2728 ssh->overall_bufsize = bufsize;
2731 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
2733 case CHAN_MAINSESSION:
2735 * This is treated separately, outside the switch.
2739 x11_override_throttle(c->u.x11.s, enable);
2742 /* Agent channels require no buffer management. */
2745 pfd_override_throttle(c->u.pfd.s, enable);
2751 static void ssh_agent_callback(void *sshv, void *reply, int replylen)
2753 Ssh ssh = (Ssh) sshv;
2755 ssh->agent_response = reply;
2756 ssh->agent_response_len = replylen;
2758 if (ssh->version == 1)
2759 do_ssh1_login(ssh, NULL, -1, NULL);
2761 do_ssh2_authconn(ssh, NULL, -1, NULL);
2764 static void ssh_dialog_callback(void *sshv, int ret)
2766 Ssh ssh = (Ssh) sshv;
2768 ssh->user_response = ret;
2770 if (ssh->version == 1)
2771 do_ssh1_login(ssh, NULL, -1, NULL);
2773 do_ssh2_transport(ssh, NULL, -1, NULL);
2776 * This may have unfrozen the SSH connection, so do a
2779 ssh_process_queued_incoming_data(ssh);
2782 static void ssh_agentf_callback(void *cv, void *reply, int replylen)
2784 struct ssh_channel *c = (struct ssh_channel *)cv;
2786 void *sentreply = reply;
2789 /* Fake SSH_AGENT_FAILURE. */
2790 sentreply = "\0\0\0\1\5";
2793 if (ssh->version == 2) {
2794 ssh2_add_channel_data(c, sentreply, replylen);
2797 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
2798 PKT_INT, c->remoteid,
2801 PKT_DATA, sentreply, replylen,
2810 * Client-initiated disconnection. Send a DISCONNECT if `wire_reason'
2811 * non-NULL, otherwise just close the connection. `client_reason' == NULL
2812 * => log `wire_reason'.
2814 static void ssh_disconnect(Ssh ssh, char *client_reason, char *wire_reason,
2815 int code, int clean_exit)
2819 client_reason = wire_reason;
2821 error = dupprintf("Disconnected: %s", client_reason);
2823 error = dupstr("Disconnected");
2825 if (ssh->version == 1) {
2826 send_packet(ssh, SSH1_MSG_DISCONNECT, PKT_STR, wire_reason,
2828 } else if (ssh->version == 2) {
2829 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
2830 ssh2_pkt_adduint32(pktout, code);
2831 ssh2_pkt_addstring(pktout, wire_reason);
2832 ssh2_pkt_addstring(pktout, "en"); /* language tag */
2833 ssh2_pkt_send_noqueue(ssh, pktout);
2836 ssh->close_expected = TRUE;
2837 ssh->clean_exit = clean_exit;
2838 ssh_closing((Plug)ssh, error, 0, 0);
2843 * Handle the key exchange and user authentication phases.
2845 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
2846 struct Packet *pktin)
2849 unsigned char cookie[8], *ptr;
2850 struct RSAKey servkey, hostkey;
2851 struct MD5Context md5c;
2852 struct do_ssh1_login_state {
2854 unsigned char *rsabuf, *keystr1, *keystr2;
2855 unsigned long supported_ciphers_mask, supported_auths_mask;
2856 int tried_publickey, tried_agent;
2857 int tis_auth_refused, ccard_auth_refused;
2858 unsigned char session_id[16];
2861 void *publickey_blob;
2862 int publickey_bloblen;
2863 char *publickey_comment;
2864 int publickey_encrypted;
2865 prompts_t *cur_prompt;
2868 unsigned char request[5], *response, *p;
2878 crState(do_ssh1_login_state);
2880 crBegin(ssh->do_ssh1_login_crstate);
2885 if (pktin->type != SSH1_SMSG_PUBLIC_KEY) {
2886 bombout(("Public key packet not received"));
2890 logevent("Received public keys");
2892 ptr = ssh_pkt_getdata(pktin, 8);
2894 bombout(("SSH-1 public key packet stopped before random cookie"));
2897 memcpy(cookie, ptr, 8);
2899 if (!ssh1_pkt_getrsakey(pktin, &servkey, &s->keystr1) ||
2900 !ssh1_pkt_getrsakey(pktin, &hostkey, &s->keystr2)) {
2901 bombout(("Failed to read SSH-1 public keys from public key packet"));
2906 * Log the host key fingerprint.
2910 logevent("Host key fingerprint is:");
2911 strcpy(logmsg, " ");
2912 hostkey.comment = NULL;
2913 rsa_fingerprint(logmsg + strlen(logmsg),
2914 sizeof(logmsg) - strlen(logmsg), &hostkey);
2918 ssh->v1_remote_protoflags = ssh_pkt_getuint32(pktin);
2919 s->supported_ciphers_mask = ssh_pkt_getuint32(pktin);
2920 s->supported_auths_mask = ssh_pkt_getuint32(pktin);
2922 ssh->v1_local_protoflags =
2923 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
2924 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
2927 MD5Update(&md5c, s->keystr2, hostkey.bytes);
2928 MD5Update(&md5c, s->keystr1, servkey.bytes);
2929 MD5Update(&md5c, cookie, 8);
2930 MD5Final(s->session_id, &md5c);
2932 for (i = 0; i < 32; i++)
2933 ssh->session_key[i] = random_byte();
2936 * Verify that the `bits' and `bytes' parameters match.
2938 if (hostkey.bits > hostkey.bytes * 8 ||
2939 servkey.bits > servkey.bytes * 8) {
2940 bombout(("SSH-1 public keys were badly formatted"));
2944 s->len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
2946 s->rsabuf = snewn(s->len, unsigned char);
2949 * Verify the host key.
2953 * First format the key into a string.
2955 int len = rsastr_len(&hostkey);
2956 char fingerprint[100];
2957 char *keystr = snewn(len, char);
2958 rsastr_fmt(keystr, &hostkey);
2959 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
2961 ssh_set_frozen(ssh, 1);
2962 s->dlgret = verify_ssh_host_key(ssh->frontend,
2963 ssh->savedhost, ssh->savedport,
2964 "rsa", keystr, fingerprint,
2965 ssh_dialog_callback, ssh);
2967 if (s->dlgret < 0) {
2971 bombout(("Unexpected data from server while waiting"
2972 " for user host key response"));
2975 } while (pktin || inlen > 0);
2976 s->dlgret = ssh->user_response;
2978 ssh_set_frozen(ssh, 0);
2980 if (s->dlgret == 0) {
2981 ssh_disconnect(ssh, "User aborted at host key verification",
2987 for (i = 0; i < 32; i++) {
2988 s->rsabuf[i] = ssh->session_key[i];
2990 s->rsabuf[i] ^= s->session_id[i];
2993 if (hostkey.bytes > servkey.bytes) {
2994 ret = rsaencrypt(s->rsabuf, 32, &servkey);
2996 ret = rsaencrypt(s->rsabuf, servkey.bytes, &hostkey);
2998 ret = rsaencrypt(s->rsabuf, 32, &hostkey);
3000 ret = rsaencrypt(s->rsabuf, hostkey.bytes, &servkey);
3003 bombout(("SSH-1 public key encryptions failed due to bad formatting"));
3007 logevent("Encrypted session key");
3010 int cipher_chosen = 0, warn = 0;
3011 char *cipher_string = NULL;
3013 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
3014 int next_cipher = ssh->cfg.ssh_cipherlist[i];
3015 if (next_cipher == CIPHER_WARN) {
3016 /* If/when we choose a cipher, warn about it */
3018 } else if (next_cipher == CIPHER_AES) {
3019 /* XXX Probably don't need to mention this. */
3020 logevent("AES not supported in SSH-1, skipping");
3022 switch (next_cipher) {
3023 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
3024 cipher_string = "3DES"; break;
3025 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
3026 cipher_string = "Blowfish"; break;
3027 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
3028 cipher_string = "single-DES"; break;
3030 if (s->supported_ciphers_mask & (1 << s->cipher_type))
3034 if (!cipher_chosen) {
3035 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
3036 bombout(("Server violates SSH-1 protocol by not "
3037 "supporting 3DES encryption"));
3039 /* shouldn't happen */
3040 bombout(("No supported ciphers found"));
3044 /* Warn about chosen cipher if necessary. */
3046 ssh_set_frozen(ssh, 1);
3047 s->dlgret = askalg(ssh->frontend, "cipher", cipher_string,
3048 ssh_dialog_callback, ssh);
3049 if (s->dlgret < 0) {
3053 bombout(("Unexpected data from server while waiting"
3054 " for user response"));
3057 } while (pktin || inlen > 0);
3058 s->dlgret = ssh->user_response;
3060 ssh_set_frozen(ssh, 0);
3061 if (s->dlgret == 0) {
3062 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
3069 switch (s->cipher_type) {
3070 case SSH_CIPHER_3DES:
3071 logevent("Using 3DES encryption");
3073 case SSH_CIPHER_DES:
3074 logevent("Using single-DES encryption");
3076 case SSH_CIPHER_BLOWFISH:
3077 logevent("Using Blowfish encryption");
3081 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
3082 PKT_CHAR, s->cipher_type,
3083 PKT_DATA, cookie, 8,
3084 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
3085 PKT_DATA, s->rsabuf, s->len,
3086 PKT_INT, ssh->v1_local_protoflags, PKT_END);
3088 logevent("Trying to enable encryption...");
3092 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
3093 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
3095 ssh->v1_cipher_ctx = ssh->cipher->make_context();
3096 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
3097 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
3099 ssh->crcda_ctx = crcda_make_context();
3100 logevent("Installing CRC compensation attack detector");
3102 if (servkey.modulus) {
3103 sfree(servkey.modulus);
3104 servkey.modulus = NULL;
3106 if (servkey.exponent) {
3107 sfree(servkey.exponent);
3108 servkey.exponent = NULL;
3110 if (hostkey.modulus) {
3111 sfree(hostkey.modulus);
3112 hostkey.modulus = NULL;
3114 if (hostkey.exponent) {
3115 sfree(hostkey.exponent);
3116 hostkey.exponent = NULL;
3120 if (pktin->type != SSH1_SMSG_SUCCESS) {
3121 bombout(("Encryption not successfully enabled"));
3125 logevent("Successfully started encryption");
3127 fflush(stdout); /* FIXME eh? */
3129 if (!*ssh->cfg.username) {
3130 int ret; /* need not be kept over crReturn */
3131 s->cur_prompt = new_prompts(ssh->frontend);
3132 s->cur_prompt->to_server = TRUE;
3133 s->cur_prompt->name = dupstr("SSH login name");
3134 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE,
3135 lenof(s->username));
3136 ret = get_userpass_input(s->cur_prompt, NULL, 0);
3139 crWaitUntil(!pktin);
3140 ret = get_userpass_input(s->cur_prompt, in, inlen);
3145 * Failed to get a username. Terminate.
3147 free_prompts(s->cur_prompt);
3148 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
3151 memcpy(s->username, s->cur_prompt->prompts[0]->result,
3152 lenof(s->username));
3153 free_prompts(s->cur_prompt);
3155 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
3156 s->username[sizeof(s->username)-1] = '\0';
3159 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, s->username, PKT_END);
3161 char *userlog = dupprintf("Sent username \"%s\"", s->username);
3163 if (flags & FLAG_INTERACTIVE &&
3164 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
3165 c_write_str(ssh, userlog);
3166 c_write_str(ssh, "\r\n");
3174 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA)) {
3175 /* We must not attempt PK auth. Pretend we've already tried it. */
3176 s->tried_publickey = s->tried_agent = 1;
3178 s->tried_publickey = s->tried_agent = 0;
3180 s->tis_auth_refused = s->ccard_auth_refused = 0;
3182 * Load the public half of any configured keyfile for later use.
3184 if (!filename_is_null(ssh->cfg.keyfile)) {
3186 logeventf(ssh, "Reading private key file \"%.150s\"",
3187 filename_to_str(&ssh->cfg.keyfile));
3188 keytype = key_type(&ssh->cfg.keyfile);
3189 if (keytype == SSH_KEYTYPE_SSH1) {
3191 if (rsakey_pubblob(&ssh->cfg.keyfile,
3192 &s->publickey_blob, &s->publickey_bloblen,
3193 &s->publickey_comment, &error)) {
3194 s->publickey_encrypted = rsakey_encrypted(&ssh->cfg.keyfile,
3198 logeventf(ssh, "Unable to load private key (%s)", error);
3199 msgbuf = dupprintf("Unable to load private key file "
3200 "\"%.150s\" (%s)\r\n",
3201 filename_to_str(&ssh->cfg.keyfile),
3203 c_write_str(ssh, msgbuf);
3205 s->publickey_blob = NULL;
3209 logeventf(ssh, "Unable to use this key file (%s)",
3210 key_type_to_str(keytype));
3211 msgbuf = dupprintf("Unable to use key file \"%.150s\""
3213 filename_to_str(&ssh->cfg.keyfile),
3214 key_type_to_str(keytype));
3215 c_write_str(ssh, msgbuf);
3217 s->publickey_blob = NULL;
3220 s->publickey_blob = NULL;
3222 while (pktin->type == SSH1_SMSG_FAILURE) {
3223 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
3225 if (agent_exists() && !s->tried_agent) {
3227 * Attempt RSA authentication using Pageant.
3233 logevent("Pageant is running. Requesting keys.");
3235 /* Request the keys held by the agent. */
3236 PUT_32BIT(s->request, 1);
3237 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
3238 if (!agent_query(s->request, 5, &r, &s->responselen,
3239 ssh_agent_callback, ssh)) {
3243 bombout(("Unexpected data from server while waiting"
3244 " for agent response"));
3247 } while (pktin || inlen > 0);
3248 r = ssh->agent_response;
3249 s->responselen = ssh->agent_response_len;
3251 s->response = (unsigned char *) r;
3252 if (s->response && s->responselen >= 5 &&
3253 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
3254 s->p = s->response + 5;
3255 s->nkeys = GET_32BIT(s->p);
3257 logeventf(ssh, "Pageant has %d SSH-1 keys", s->nkeys);
3258 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
3259 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
3260 if (s->publickey_blob &&
3261 !memcmp(s->p, s->publickey_blob,
3262 s->publickey_bloblen)) {
3263 logevent("This key matches configured key file");
3264 s->tried_publickey = 1;
3269 do { /* do while (0) to make breaking easy */
3270 n = ssh1_read_bignum
3271 (s->p, s->responselen-(s->p-s->response),
3276 n = ssh1_read_bignum
3277 (s->p, s->responselen-(s->p-s->response),
3282 if (s->responselen - (s->p-s->response) < 4)
3284 s->commentlen = GET_32BIT(s->p);
3286 if (s->responselen - (s->p-s->response) <
3289 s->commentp = (char *)s->p;
3290 s->p += s->commentlen;
3294 logevent("Pageant key list packet was truncated");
3298 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3299 PKT_BIGNUM, s->key.modulus, PKT_END);
3301 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
3302 logevent("Key refused");
3305 logevent("Received RSA challenge");
3306 if ((s->challenge = ssh1_pkt_getmp(pktin)) == NULL) {
3307 bombout(("Server's RSA challenge was badly formatted"));
3312 char *agentreq, *q, *ret;
3315 len = 1 + 4; /* message type, bit count */
3316 len += ssh1_bignum_length(s->key.exponent);
3317 len += ssh1_bignum_length(s->key.modulus);
3318 len += ssh1_bignum_length(s->challenge);
3319 len += 16; /* session id */
3320 len += 4; /* response format */
3321 agentreq = snewn(4 + len, char);
3322 PUT_32BIT(agentreq, len);
3324 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
3325 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
3327 q += ssh1_write_bignum(q, s->key.exponent);
3328 q += ssh1_write_bignum(q, s->key.modulus);
3329 q += ssh1_write_bignum(q, s->challenge);
3330 memcpy(q, s->session_id, 16);
3332 PUT_32BIT(q, 1); /* response format */
3333 if (!agent_query(agentreq, len + 4, &vret, &retlen,
3334 ssh_agent_callback, ssh)) {
3339 bombout(("Unexpected data from server"
3340 " while waiting for agent"
3344 } while (pktin || inlen > 0);
3345 vret = ssh->agent_response;
3346 retlen = ssh->agent_response_len;
3351 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
3352 logevent("Sending Pageant's response");
3353 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
3354 PKT_DATA, ret + 5, 16,
3358 if (pktin->type == SSH1_SMSG_SUCCESS) {
3360 ("Pageant's response accepted");
3361 if (flags & FLAG_VERBOSE) {
3362 c_write_str(ssh, "Authenticated using"
3364 c_write(ssh, s->commentp,
3366 c_write_str(ssh, "\" from agent\r\n");
3371 ("Pageant's response not accepted");
3374 ("Pageant failed to answer challenge");
3378 logevent("No reply received from Pageant");
3381 freebn(s->key.exponent);
3382 freebn(s->key.modulus);
3383 freebn(s->challenge);
3392 if (s->publickey_blob && !s->tried_publickey) {
3394 * Try public key authentication with the specified
3397 int got_passphrase; /* need not be kept over crReturn */
3398 if (flags & FLAG_VERBOSE)
3399 c_write_str(ssh, "Trying public key authentication.\r\n");
3400 logeventf(ssh, "Trying public key \"%s\"",
3401 filename_to_str(&ssh->cfg.keyfile));
3402 s->tried_publickey = 1;
3403 got_passphrase = FALSE;
3404 while (!got_passphrase) {
3406 * Get a passphrase, if necessary.
3408 char *passphrase = NULL; /* only written after crReturn */
3410 if (!s->publickey_encrypted) {
3411 if (flags & FLAG_VERBOSE)
3412 c_write_str(ssh, "No passphrase required.\r\n");
3415 int ret; /* need not be kept over crReturn */
3416 s->cur_prompt = new_prompts(ssh->frontend);
3417 s->cur_prompt->to_server = FALSE;
3418 s->cur_prompt->name = dupstr("SSH key passphrase");
3419 add_prompt(s->cur_prompt,
3420 dupprintf("Passphrase for key \"%.100s\": ",
3421 s->publickey_comment),
3422 FALSE, SSH_MAX_PASSWORD_LEN);
3423 ret = get_userpass_input(s->cur_prompt, NULL, 0);
3426 crWaitUntil(!pktin);
3427 ret = get_userpass_input(s->cur_prompt, in, inlen);
3431 /* Failed to get a passphrase. Terminate. */
3432 free_prompts(s->cur_prompt);
3433 ssh_disconnect(ssh, NULL, "Unable to authenticate",
3437 passphrase = dupstr(s->cur_prompt->prompts[0]->result);
3438 free_prompts(s->cur_prompt);
3441 * Try decrypting key with passphrase.
3443 ret = loadrsakey(&ssh->cfg.keyfile, &s->key, passphrase,
3446 memset(passphrase, 0, strlen(passphrase));
3450 /* Correct passphrase. */
3451 got_passphrase = TRUE;
3452 } else if (ret == 0) {
3453 c_write_str(ssh, "Couldn't load private key from ");
3454 c_write_str(ssh, filename_to_str(&ssh->cfg.keyfile));
3455 c_write_str(ssh, " (");
3456 c_write_str(ssh, error);
3457 c_write_str(ssh, ").\r\n");
3458 got_passphrase = FALSE;
3459 break; /* go and try something else */
3460 } else if (ret == -1) {
3461 c_write_str(ssh, "Wrong passphrase.\r\n"); /* FIXME */
3462 s->tried_publickey = 0;
3463 got_passphrase = FALSE;
3468 if (got_passphrase) {
3471 * Send a public key attempt.
3473 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3474 PKT_BIGNUM, s->key.modulus, PKT_END);
3477 if (pktin->type == SSH1_SMSG_FAILURE) {
3478 c_write_str(ssh, "Server refused our public key.\r\n");
3479 continue; /* go and try password */
3481 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
3482 bombout(("Bizarre response to offer of public key"));
3488 unsigned char buffer[32];
3489 Bignum challenge, response;
3491 if ((challenge = ssh1_pkt_getmp(pktin)) == NULL) {
3492 bombout(("Server's RSA challenge was badly formatted"));
3495 response = rsadecrypt(challenge, &s->key);
3496 freebn(s->key.private_exponent);/* burn the evidence */
3498 for (i = 0; i < 32; i++) {
3499 buffer[i] = bignum_byte(response, 31 - i);
3503 MD5Update(&md5c, buffer, 32);
3504 MD5Update(&md5c, s->session_id, 16);
3505 MD5Final(buffer, &md5c);
3507 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
3508 PKT_DATA, buffer, 16, PKT_END);
3515 if (pktin->type == SSH1_SMSG_FAILURE) {
3516 if (flags & FLAG_VERBOSE)
3517 c_write_str(ssh, "Failed to authenticate with"
3518 " our public key.\r\n");
3519 continue; /* go and try password */
3520 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
3521 bombout(("Bizarre response to RSA authentication response"));
3525 break; /* we're through! */
3531 * Otherwise, try various forms of password-like authentication.
3533 s->cur_prompt = new_prompts(ssh->frontend);
3535 if (ssh->cfg.try_tis_auth &&
3536 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
3537 !s->tis_auth_refused) {
3538 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
3539 logevent("Requested TIS authentication");
3540 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
3542 if (pktin->type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
3543 logevent("TIS authentication declined");
3544 if (flags & FLAG_INTERACTIVE)
3545 c_write_str(ssh, "TIS authentication refused.\r\n");
3546 s->tis_auth_refused = 1;
3551 char *instr_suf, *prompt;
3553 ssh_pkt_getstring(pktin, &challenge, &challengelen);
3555 bombout(("TIS challenge packet was badly formed"));
3558 logevent("Received TIS challenge");
3559 s->cur_prompt->to_server = TRUE;
3560 s->cur_prompt->name = dupstr("SSH TIS authentication");
3561 /* Prompt heuristic comes from OpenSSH */
3562 if (memchr(challenge, '\n', challengelen)) {
3563 instr_suf = dupstr("");
3564 prompt = dupprintf("%.*s", challengelen, challenge);
3566 instr_suf = dupprintf("%.*s", challengelen, challenge);
3567 prompt = dupstr("Response: ");
3569 s->cur_prompt->instruction =
3570 dupprintf("Using TIS authentication.%s%s",
3571 (*instr_suf) ? "\n" : "",
3573 s->cur_prompt->instr_reqd = TRUE;
3574 add_prompt(s->cur_prompt, prompt, FALSE, SSH_MAX_PASSWORD_LEN);
3578 if (ssh->cfg.try_tis_auth &&
3579 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
3580 !s->ccard_auth_refused) {
3581 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
3582 logevent("Requested CryptoCard authentication");
3583 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
3585 if (pktin->type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
3586 logevent("CryptoCard authentication declined");
3587 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
3588 s->ccard_auth_refused = 1;
3593 char *instr_suf, *prompt;
3595 ssh_pkt_getstring(pktin, &challenge, &challengelen);
3597 bombout(("CryptoCard challenge packet was badly formed"));
3600 logevent("Received CryptoCard challenge");
3601 s->cur_prompt->to_server = TRUE;
3602 s->cur_prompt->name = dupstr("SSH CryptoCard authentication");
3603 s->cur_prompt->name_reqd = FALSE;
3604 /* Prompt heuristic comes from OpenSSH */
3605 if (memchr(challenge, '\n', challengelen)) {
3606 instr_suf = dupstr("");
3607 prompt = dupprintf("%.*s", challengelen, challenge);
3609 instr_suf = dupprintf("%.*s", challengelen, challenge);
3610 prompt = dupstr("Response: ");
3612 s->cur_prompt->instruction =
3613 dupprintf("Using CryptoCard authentication.%s%s",
3614 (*instr_suf) ? "\n" : "",
3616 s->cur_prompt->instr_reqd = TRUE;
3617 add_prompt(s->cur_prompt, prompt, FALSE, SSH_MAX_PASSWORD_LEN);
3621 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
3622 s->cur_prompt->to_server = TRUE;
3623 s->cur_prompt->name = dupstr("SSH password");
3624 add_prompt(s->cur_prompt, dupprintf("%.90s@%.90s's password: ",
3625 s->username, ssh->savedhost),
3626 FALSE, SSH_MAX_PASSWORD_LEN);
3630 * Show password prompt, having first obtained it via a TIS
3631 * or CryptoCard exchange if we're doing TIS or CryptoCard
3635 int ret; /* need not be kept over crReturn */
3636 ret = get_userpass_input(s->cur_prompt, NULL, 0);
3639 crWaitUntil(!pktin);
3640 ret = get_userpass_input(s->cur_prompt, in, inlen);
3645 * Failed to get a password (for example
3646 * because one was supplied on the command line
3647 * which has already failed to work). Terminate.
3649 free_prompts(s->cur_prompt);
3650 ssh_disconnect(ssh, NULL, "Unable to authenticate", 0, TRUE);
3655 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
3657 * Defence against traffic analysis: we send a
3658 * whole bunch of packets containing strings of
3659 * different lengths. One of these strings is the
3660 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
3661 * The others are all random data in
3662 * SSH1_MSG_IGNORE packets. This way a passive
3663 * listener can't tell which is the password, and
3664 * hence can't deduce the password length.
3666 * Anybody with a password length greater than 16
3667 * bytes is going to have enough entropy in their
3668 * password that a listener won't find it _that_
3669 * much help to know how long it is. So what we'll
3672 * - if password length < 16, we send 15 packets
3673 * containing string lengths 1 through 15
3675 * - otherwise, we let N be the nearest multiple
3676 * of 8 below the password length, and send 8
3677 * packets containing string lengths N through
3678 * N+7. This won't obscure the order of
3679 * magnitude of the password length, but it will
3680 * introduce a bit of extra uncertainty.
3682 * A few servers (the old 1.2.18 through 1.2.22)
3683 * can't deal with SSH1_MSG_IGNORE. For these
3684 * servers, we need an alternative defence. We make
3685 * use of the fact that the password is interpreted
3686 * as a C string: so we can append a NUL, then some
3689 * One server (a Cisco one) can deal with neither
3690 * SSH1_MSG_IGNORE _nor_ a padded password string.
3691 * For this server we are left with no defences
3692 * against password length sniffing.
3694 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) {
3696 * The server can deal with SSH1_MSG_IGNORE, so
3697 * we can use the primary defence.
3699 int bottom, top, pwlen, i;
3702 pwlen = strlen(s->cur_prompt->prompts[0]->result);
3704 bottom = 0; /* zero length passwords are OK! :-) */
3707 bottom = pwlen & ~7;
3711 assert(pwlen >= bottom && pwlen <= top);
3713 randomstr = snewn(top + 1, char);
3715 for (i = bottom; i <= top; i++) {
3717 defer_packet(ssh, s->pwpkt_type,
3718 PKTT_PASSWORD, PKT_STR,
3719 s->cur_prompt->prompts[0]->result,
3720 PKTT_OTHER, PKT_END);
3722 for (j = 0; j < i; j++) {
3724 randomstr[j] = random_byte();
3725 } while (randomstr[j] == '\0');
3727 randomstr[i] = '\0';
3728 defer_packet(ssh, SSH1_MSG_IGNORE,
3729 PKT_STR, randomstr, PKT_END);
3732 logevent("Sending password with camouflage packets");
3733 ssh_pkt_defersend(ssh);
3736 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
3738 * The server can't deal with SSH1_MSG_IGNORE
3739 * but can deal with padded passwords, so we
3740 * can use the secondary defence.
3746 len = strlen(s->cur_prompt->prompts[0]->result);
3747 if (len < sizeof(string)) {
3749 strcpy(string, s->cur_prompt->prompts[0]->result);
3750 len++; /* cover the zero byte */
3751 while (len < sizeof(string)) {
3752 string[len++] = (char) random_byte();
3755 ss = s->cur_prompt->prompts[0]->result;
3757 logevent("Sending length-padded password");
3758 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
3759 PKT_INT, len, PKT_DATA, ss, len,
3760 PKTT_OTHER, PKT_END);
3763 * The server has _both_
3764 * BUG_CHOKES_ON_SSH1_IGNORE and
3765 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
3766 * therefore nothing we can do.
3769 len = strlen(s->cur_prompt->prompts[0]->result);
3770 logevent("Sending unpadded password");
3771 send_packet(ssh, s->pwpkt_type,
3772 PKTT_PASSWORD, PKT_INT, len,
3773 PKT_DATA, s->cur_prompt->prompts[0]->result, len,
3774 PKTT_OTHER, PKT_END);
3777 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
3778 PKT_STR, s->cur_prompt->prompts[0]->result,
3779 PKTT_OTHER, PKT_END);
3781 logevent("Sent password");
3782 free_prompts(s->cur_prompt);
3784 if (pktin->type == SSH1_SMSG_FAILURE) {
3785 if (flags & FLAG_VERBOSE)
3786 c_write_str(ssh, "Access denied\r\n");
3787 logevent("Authentication refused");
3788 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
3789 bombout(("Strange packet received, type %d", pktin->type));
3795 if (s->publickey_blob) {
3796 sfree(s->publickey_blob);
3797 sfree(s->publickey_comment);
3800 logevent("Authentication successful");
3805 void sshfwd_close(struct ssh_channel *c)
3809 if (ssh->state == SSH_STATE_CLOSED)
3812 if (c && !c->closes) {
3814 * If halfopen is true, we have sent
3815 * CHANNEL_OPEN for this channel, but it hasn't even been
3816 * acknowledged by the server. So we must set a close flag
3817 * on it now, and then when the server acks the channel
3818 * open, we can close it then.
3821 if (ssh->version == 1) {
3822 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
3825 struct Packet *pktout;
3826 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
3827 ssh2_pkt_adduint32(pktout, c->remoteid);
3828 ssh2_pkt_send(ssh, pktout);
3831 c->closes = 1; /* sent MSG_CLOSE */
3832 if (c->type == CHAN_X11) {
3834 logevent("Forwarded X11 connection terminated");
3835 } else if (c->type == CHAN_SOCKDATA ||
3836 c->type == CHAN_SOCKDATA_DORMANT) {
3838 logevent("Forwarded port closed");
3843 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
3847 if (ssh->state == SSH_STATE_CLOSED)
3850 if (ssh->version == 1) {
3851 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
3852 PKT_INT, c->remoteid,
3854 PKT_INT, len, PKT_DATA, buf, len,
3855 PKTT_OTHER, PKT_END);
3857 * In SSH-1 we can return 0 here - implying that forwarded
3858 * connections are never individually throttled - because
3859 * the only circumstance that can cause throttling will be
3860 * the whole SSH connection backing up, in which case
3861 * _everything_ will be throttled as a whole.
3865 ssh2_add_channel_data(c, buf, len);
3866 return ssh2_try_send(c);
3870 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
3874 if (ssh->state == SSH_STATE_CLOSED)
3877 if (ssh->version == 1) {
3878 if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
3879 c->v.v1.throttling = 0;
3880 ssh1_throttle(ssh, -1);
3883 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
3887 static void ssh_queueing_handler(Ssh ssh, struct Packet *pktin)
3889 struct queued_handler *qh = ssh->qhead;
3893 assert(pktin->type == qh->msg1 || pktin->type == qh->msg2);
3896 assert(ssh->packet_dispatch[qh->msg1] == ssh_queueing_handler);
3897 ssh->packet_dispatch[qh->msg1] = NULL;
3900 assert(ssh->packet_dispatch[qh->msg2] == ssh_queueing_handler);
3901 ssh->packet_dispatch[qh->msg2] = NULL;
3905 ssh->qhead = qh->next;
3907 if (ssh->qhead->msg1 > 0) {
3908 assert(ssh->packet_dispatch[ssh->qhead->msg1] == NULL);
3909 ssh->packet_dispatch[ssh->qhead->msg1] = ssh_queueing_handler;
3911 if (ssh->qhead->msg2 > 0) {
3912 assert(ssh->packet_dispatch[ssh->qhead->msg2] == NULL);
3913 ssh->packet_dispatch[ssh->qhead->msg2] = ssh_queueing_handler;
3916 ssh->qhead = ssh->qtail = NULL;
3917 ssh->packet_dispatch[pktin->type] = NULL;
3920 qh->handler(ssh, pktin, qh->ctx);
3925 static void ssh_queue_handler(Ssh ssh, int msg1, int msg2,
3926 chandler_fn_t handler, void *ctx)
3928 struct queued_handler *qh;
3930 qh = snew(struct queued_handler);
3933 qh->handler = handler;
3937 if (ssh->qtail == NULL) {
3941 assert(ssh->packet_dispatch[qh->msg1] == NULL);
3942 ssh->packet_dispatch[qh->msg1] = ssh_queueing_handler;
3945 assert(ssh->packet_dispatch[qh->msg2] == NULL);
3946 ssh->packet_dispatch[qh->msg2] = ssh_queueing_handler;
3949 ssh->qtail->next = qh;
3954 static void ssh_rportfwd_succfail(Ssh ssh, struct Packet *pktin, void *ctx)
3956 struct ssh_rportfwd *rpf, *pf = (struct ssh_rportfwd *)ctx;
3958 if (pktin->type == (ssh->version == 1 ? SSH1_SMSG_SUCCESS :
3959 SSH2_MSG_REQUEST_SUCCESS)) {
3960 logeventf(ssh, "Remote port forwarding from %s enabled",
3963 logeventf(ssh, "Remote port forwarding from %s refused",
3966 rpf = del234(ssh->rportfwds, pf);
3972 static void ssh_setup_portfwd(Ssh ssh, const Config *cfg)
3974 const char *portfwd_strptr = cfg->portfwd;
3975 struct ssh_portfwd *epf;
3978 if (!ssh->portfwds) {
3979 ssh->portfwds = newtree234(ssh_portcmp);
3982 * Go through the existing port forwardings and tag them
3983 * with status==DESTROY. Any that we want to keep will be
3984 * re-enabled (status==KEEP) as we go through the
3985 * configuration and find out which bits are the same as
3988 struct ssh_portfwd *epf;
3990 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
3991 epf->status = DESTROY;
3994 while (*portfwd_strptr) {
3995 char address_family, type;
3996 int sport,dport,sserv,dserv;
3997 char sports[256], dports[256], saddr[256], host[256];
4000 address_family = 'A';
4002 if (*portfwd_strptr == 'A' ||
4003 *portfwd_strptr == '4' ||
4004 *portfwd_strptr == '6')
4005 address_family = *portfwd_strptr++;
4006 if (*portfwd_strptr == 'L' ||
4007 *portfwd_strptr == 'R' ||
4008 *portfwd_strptr == 'D')
4009 type = *portfwd_strptr++;
4014 while (*portfwd_strptr && *portfwd_strptr != '\t') {
4015 if (*portfwd_strptr == ':') {
4017 * We've seen a colon in the middle of the
4018 * source port number. This means that
4019 * everything we've seen until now is the
4020 * source _address_, so we'll move it into
4021 * saddr and start sports from the beginning
4026 if (ssh->version == 1 && type == 'R') {
4027 logeventf(ssh, "SSH-1 cannot handle remote source address "
4028 "spec \"%s\"; ignoring", sports);
4030 strcpy(saddr, sports);
4033 if (n < lenof(sports)-1) sports[n++] = *portfwd_strptr++;
4037 if (*portfwd_strptr == '\t')
4040 while (*portfwd_strptr && *portfwd_strptr != ':') {
4041 if (n < lenof(host)-1) host[n++] = *portfwd_strptr++;
4044 if (*portfwd_strptr == ':')
4047 while (*portfwd_strptr) {
4048 if (n < lenof(dports)-1) dports[n++] = *portfwd_strptr++;
4052 dport = atoi(dports);
4056 dport = net_service_lookup(dports);
4058 logeventf(ssh, "Service lookup failed for destination"
4059 " port \"%s\"", dports);
4063 while (*portfwd_strptr) portfwd_strptr++;
4067 portfwd_strptr++; /* eat the NUL and move to next one */
4069 sport = atoi(sports);
4073 sport = net_service_lookup(sports);
4075 logeventf(ssh, "Service lookup failed for source"
4076 " port \"%s\"", sports);
4079 if (sport && dport) {
4080 /* Set up a description of the source port. */
4081 struct ssh_portfwd *pfrec, *epfrec;
4083 pfrec = snew(struct ssh_portfwd);
4085 pfrec->saddr = *saddr ? dupstr(saddr) : NULL;
4086 pfrec->sserv = sserv ? dupstr(sports) : NULL;
4087 pfrec->sport = sport;
4088 pfrec->daddr = *host ? dupstr(host) : NULL;
4089 pfrec->dserv = dserv ? dupstr(dports) : NULL;
4090 pfrec->dport = dport;
4091 pfrec->local = NULL;
4092 pfrec->remote = NULL;
4093 pfrec->addressfamily = (address_family == '4' ? ADDRTYPE_IPV4 :
4094 address_family == '6' ? ADDRTYPE_IPV6 :
4097 epfrec = add234(ssh->portfwds, pfrec);
4098 if (epfrec != pfrec) {
4100 * We already have a port forwarding with precisely
4101 * these parameters. Hence, no need to do anything;
4102 * simply tag the existing one as KEEP.
4104 epfrec->status = KEEP;
4105 free_portfwd(pfrec);
4107 pfrec->status = CREATE;
4113 * Now go through and destroy any port forwardings which were
4116 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
4117 if (epf->status == DESTROY) {
4120 message = dupprintf("%s port forwarding from %s%s%d",
4121 epf->type == 'L' ? "local" :
4122 epf->type == 'R' ? "remote" : "dynamic",
4123 epf->saddr ? epf->saddr : "",
4124 epf->saddr ? ":" : "",
4127 if (epf->type != 'D') {
4128 char *msg2 = dupprintf("%s to %s:%d", message,
4129 epf->daddr, epf->dport);
4134 logeventf(ssh, "Cancelling %s", message);
4138 struct ssh_rportfwd *rpf = epf->remote;
4139 struct Packet *pktout;
4142 * Cancel the port forwarding at the server
4145 if (ssh->version == 1) {
4147 * We cannot cancel listening ports on the
4148 * server side in SSH-1! There's no message
4149 * to support it. Instead, we simply remove
4150 * the rportfwd record from the local end
4151 * so that any connections the server tries
4152 * to make on it are rejected.
4155 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
4156 ssh2_pkt_addstring(pktout, "cancel-tcpip-forward");
4157 ssh2_pkt_addbool(pktout, 0);/* _don't_ want reply */
4159 ssh2_pkt_addstring(pktout, epf->saddr);
4160 } else if (ssh->cfg.rport_acceptall) {
4161 /* XXX: ssh->cfg.rport_acceptall may not represent
4162 * what was used to open the original connection,
4163 * since it's reconfigurable. */
4164 ssh2_pkt_addstring(pktout, "0.0.0.0");
4166 ssh2_pkt_addstring(pktout, "127.0.0.1");
4168 ssh2_pkt_adduint32(pktout, epf->sport);
4169 ssh2_pkt_send(ssh, pktout);
4172 del234(ssh->rportfwds, rpf);
4174 } else if (epf->local) {
4175 pfd_terminate(epf->local);
4178 delpos234(ssh->portfwds, i);
4180 i--; /* so we don't skip one in the list */
4184 * And finally, set up any new port forwardings (status==CREATE).
4186 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
4187 if (epf->status == CREATE) {
4188 char *sportdesc, *dportdesc;
4189 sportdesc = dupprintf("%s%s%s%s%d%s",
4190 epf->saddr ? epf->saddr : "",
4191 epf->saddr ? ":" : "",
4192 epf->sserv ? epf->sserv : "",
4193 epf->sserv ? "(" : "",
4195 epf->sserv ? ")" : "");
4196 if (epf->type == 'D') {
4199 dportdesc = dupprintf("%s:%s%s%d%s",
4201 epf->dserv ? epf->dserv : "",
4202 epf->dserv ? "(" : "",
4204 epf->dserv ? ")" : "");
4207 if (epf->type == 'L') {
4208 const char *err = pfd_addforward(epf->daddr, epf->dport,
4209 epf->saddr, epf->sport,
4212 epf->addressfamily);
4214 logeventf(ssh, "Local %sport %s forwarding to %s%s%s",
4215 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
4216 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
4217 sportdesc, dportdesc,
4218 err ? " failed: " : "", err ? err : "");
4219 } else if (epf->type == 'D') {
4220 const char *err = pfd_addforward(NULL, -1,
4221 epf->saddr, epf->sport,
4224 epf->addressfamily);
4226 logeventf(ssh, "Local %sport %s SOCKS dynamic forwarding%s%s",
4227 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
4228 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
4230 err ? " failed: " : "", err ? err : "");
4232 struct ssh_rportfwd *pf;
4235 * Ensure the remote port forwardings tree exists.
4237 if (!ssh->rportfwds) {
4238 if (ssh->version == 1)
4239 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
4241 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
4244 pf = snew(struct ssh_rportfwd);
4245 strncpy(pf->dhost, epf->daddr, lenof(pf->dhost)-1);
4246 pf->dhost[lenof(pf->dhost)-1] = '\0';
4247 pf->dport = epf->dport;
4248 pf->sport = epf->sport;
4249 if (add234(ssh->rportfwds, pf) != pf) {
4250 logeventf(ssh, "Duplicate remote port forwarding to %s:%d",
4251 epf->daddr, epf->dport);
4254 logeventf(ssh, "Requesting remote port %s"
4255 " forward to %s", sportdesc, dportdesc);
4257 pf->sportdesc = sportdesc;
4262 if (ssh->version == 1) {
4263 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
4264 PKT_INT, epf->sport,
4265 PKT_STR, epf->daddr,
4266 PKT_INT, epf->dport,
4268 ssh_queue_handler(ssh, SSH1_SMSG_SUCCESS,
4270 ssh_rportfwd_succfail, pf);
4272 struct Packet *pktout;
4273 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
4274 ssh2_pkt_addstring(pktout, "tcpip-forward");
4275 ssh2_pkt_addbool(pktout, 1);/* want reply */
4277 ssh2_pkt_addstring(pktout, epf->saddr);
4278 } else if (cfg->rport_acceptall) {
4279 ssh2_pkt_addstring(pktout, "0.0.0.0");
4281 ssh2_pkt_addstring(pktout, "127.0.0.1");
4283 ssh2_pkt_adduint32(pktout, epf->sport);
4284 ssh2_pkt_send(ssh, pktout);
4286 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS,
4287 SSH2_MSG_REQUEST_FAILURE,
4288 ssh_rportfwd_succfail, pf);
4297 static void ssh1_smsg_stdout_stderr_data(Ssh ssh, struct Packet *pktin)
4300 int stringlen, bufsize;
4302 ssh_pkt_getstring(pktin, &string, &stringlen);
4303 if (string == NULL) {
4304 bombout(("Incoming terminal data packet was badly formed"));
4308 bufsize = from_backend(ssh->frontend, pktin->type == SSH1_SMSG_STDERR_DATA,
4310 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
4311 ssh->v1_stdout_throttling = 1;
4312 ssh1_throttle(ssh, +1);
4316 static void ssh1_smsg_x11_open(Ssh ssh, struct Packet *pktin)
4318 /* Remote side is trying to open a channel to talk to our
4319 * X-Server. Give them back a local channel number. */
4320 struct ssh_channel *c;
4321 int remoteid = ssh_pkt_getuint32(pktin);
4323 logevent("Received X11 connect request");
4324 /* Refuse if X11 forwarding is disabled. */
4325 if (!ssh->X11_fwd_enabled) {
4326 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4327 PKT_INT, remoteid, PKT_END);
4328 logevent("Rejected X11 connect request");
4330 c = snew(struct ssh_channel);
4333 if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
4334 ssh->x11auth, NULL, -1, &ssh->cfg) != NULL) {
4335 logevent("Opening X11 forward connection failed");
4337 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4338 PKT_INT, remoteid, PKT_END);
4341 ("Opening X11 forward connection succeeded");
4342 c->remoteid = remoteid;
4343 c->halfopen = FALSE;
4344 c->localid = alloc_channel_id(ssh);
4346 c->v.v1.throttling = 0;
4347 c->type = CHAN_X11; /* identify channel type */
4348 add234(ssh->channels, c);
4349 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4350 PKT_INT, c->remoteid, PKT_INT,
4351 c->localid, PKT_END);
4352 logevent("Opened X11 forward channel");
4357 static void ssh1_smsg_agent_open(Ssh ssh, struct Packet *pktin)
4359 /* Remote side is trying to open a channel to talk to our
4360 * agent. Give them back a local channel number. */
4361 struct ssh_channel *c;
4362 int remoteid = ssh_pkt_getuint32(pktin);
4364 /* Refuse if agent forwarding is disabled. */
4365 if (!ssh->agentfwd_enabled) {
4366 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4367 PKT_INT, remoteid, PKT_END);
4369 c = snew(struct ssh_channel);
4371 c->remoteid = remoteid;
4372 c->halfopen = FALSE;
4373 c->localid = alloc_channel_id(ssh);
4375 c->v.v1.throttling = 0;
4376 c->type = CHAN_AGENT; /* identify channel type */
4377 c->u.a.lensofar = 0;
4378 add234(ssh->channels, c);
4379 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4380 PKT_INT, c->remoteid, PKT_INT, c->localid,
4385 static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin)
4387 /* Remote side is trying to open a channel to talk to a
4388 * forwarded port. Give them back a local channel number. */
4389 struct ssh_channel *c;
4390 struct ssh_rportfwd pf, *pfp;
4395 c = snew(struct ssh_channel);
4398 remoteid = ssh_pkt_getuint32(pktin);
4399 ssh_pkt_getstring(pktin, &host, &hostsize);
4400 port = ssh_pkt_getuint32(pktin);
4402 if (hostsize >= lenof(pf.dhost))
4403 hostsize = lenof(pf.dhost)-1;
4404 memcpy(pf.dhost, host, hostsize);
4405 pf.dhost[hostsize] = '\0';
4407 pfp = find234(ssh->rportfwds, &pf, NULL);
4410 logeventf(ssh, "Rejected remote port open request for %s:%d",
4412 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4413 PKT_INT, remoteid, PKT_END);
4415 logeventf(ssh, "Received remote port open request for %s:%d",
4417 e = pfd_newconnect(&c->u.pfd.s, pf.dhost, port,
4418 c, &ssh->cfg, pfp->pfrec->addressfamily);
4420 logeventf(ssh, "Port open failed: %s", e);
4422 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4423 PKT_INT, remoteid, PKT_END);
4425 c->remoteid = remoteid;
4426 c->halfopen = FALSE;
4427 c->localid = alloc_channel_id(ssh);
4429 c->v.v1.throttling = 0;
4430 c->type = CHAN_SOCKDATA; /* identify channel type */
4431 add234(ssh->channels, c);
4432 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4433 PKT_INT, c->remoteid, PKT_INT,
4434 c->localid, PKT_END);
4435 logevent("Forwarded port opened successfully");
4440 static void ssh1_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
4442 unsigned int remoteid = ssh_pkt_getuint32(pktin);
4443 unsigned int localid = ssh_pkt_getuint32(pktin);
4444 struct ssh_channel *c;
4446 c = find234(ssh->channels, &remoteid, ssh_channelfind);
4447 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
4448 c->remoteid = localid;
4449 c->halfopen = FALSE;
4450 c->type = CHAN_SOCKDATA;
4451 c->v.v1.throttling = 0;
4452 pfd_confirm(c->u.pfd.s);
4455 if (c && c->closes) {
4457 * We have a pending close on this channel,
4458 * which we decided on before the server acked
4459 * the channel open. So now we know the
4460 * remoteid, we can close it again.
4462 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE,
4463 PKT_INT, c->remoteid, PKT_END);
4467 static void ssh1_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
4469 unsigned int remoteid = ssh_pkt_getuint32(pktin);
4470 struct ssh_channel *c;
4472 c = find234(ssh->channels, &remoteid, ssh_channelfind);
4473 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
4474 logevent("Forwarded connection refused by server");
4475 pfd_close(c->u.pfd.s);
4476 del234(ssh->channels, c);
4481 static void ssh1_msg_channel_close(Ssh ssh, struct Packet *pktin)
4483 /* Remote side closes a channel. */
4484 unsigned i = ssh_pkt_getuint32(pktin);
4485 struct ssh_channel *c;
4486 c = find234(ssh->channels, &i, ssh_channelfind);
4487 if (c && !c->halfopen) {
4490 (pktin->type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
4492 if ((c->closes == 0) && (c->type == CHAN_X11)) {
4493 logevent("Forwarded X11 connection terminated");
4494 assert(c->u.x11.s != NULL);
4495 x11_close(c->u.x11.s);
4498 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
4499 logevent("Forwarded port closed");
4500 assert(c->u.pfd.s != NULL);
4501 pfd_close(c->u.pfd.s);
4505 c->closes |= (closetype << 2); /* seen this message */
4506 if (!(c->closes & closetype)) {
4507 send_packet(ssh, pktin->type, PKT_INT, c->remoteid,
4509 c->closes |= closetype; /* sent it too */
4512 if (c->closes == 15) {
4513 del234(ssh->channels, c);
4517 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
4518 pktin->type == SSH1_MSG_CHANNEL_CLOSE ? "" :
4519 "_CONFIRMATION", c ? "half-open" : "nonexistent",
4524 static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin)
4526 /* Data sent down one of our channels. */
4527 int i = ssh_pkt_getuint32(pktin);
4530 struct ssh_channel *c;
4532 ssh_pkt_getstring(pktin, &p, &len);
4534 c = find234(ssh->channels, &i, ssh_channelfind);
4539 bufsize = x11_send(c->u.x11.s, p, len);
4542 bufsize = pfd_send(c->u.pfd.s, p, len);
4545 /* Data for an agent message. Buffer it. */
4547 if (c->u.a.lensofar < 4) {
4548 unsigned int l = min(4 - c->u.a.lensofar, len);
4549 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
4553 c->u.a.lensofar += l;
4555 if (c->u.a.lensofar == 4) {
4557 4 + GET_32BIT(c->u.a.msglen);
4558 c->u.a.message = snewn(c->u.a.totallen,
4560 memcpy(c->u.a.message, c->u.a.msglen, 4);
4562 if (c->u.a.lensofar >= 4 && len > 0) {
4564 min(c->u.a.totallen - c->u.a.lensofar,
4566 memcpy(c->u.a.message + c->u.a.lensofar, p,
4570 c->u.a.lensofar += l;
4572 if (c->u.a.lensofar == c->u.a.totallen) {
4575 if (agent_query(c->u.a.message,
4578 ssh_agentf_callback, c))
4579 ssh_agentf_callback(c, reply, replylen);
4580 sfree(c->u.a.message);
4581 c->u.a.lensofar = 0;
4584 bufsize = 0; /* agent channels never back up */
4587 if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
4588 c->v.v1.throttling = 1;
4589 ssh1_throttle(ssh, +1);
4594 static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin)
4596 ssh->exitcode = ssh_pkt_getuint32(pktin);
4597 logeventf(ssh, "Server sent command exit status %d", ssh->exitcode);
4598 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
4600 * In case `helpful' firewalls or proxies tack
4601 * extra human-readable text on the end of the
4602 * session which we might mistake for another
4603 * encrypted packet, we close the session once
4604 * we've sent EXIT_CONFIRMATION.
4606 ssh_disconnect(ssh, NULL, NULL, 0, TRUE);
4609 /* Helper function to deal with sending tty modes for REQUEST_PTY */
4610 static void ssh1_send_ttymode(void *data, char *mode, char *val)
4612 struct Packet *pktout = (struct Packet *)data;
4614 unsigned int arg = 0;
4615 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
4616 if (i == lenof(ssh_ttymodes)) return;
4617 switch (ssh_ttymodes[i].type) {
4619 arg = ssh_tty_parse_specchar(val);
4622 arg = ssh_tty_parse_boolean(val);
4625 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
4626 ssh2_pkt_addbyte(pktout, arg);
4630 static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen,
4631 struct Packet *pktin)
4633 crBegin(ssh->do_ssh1_connection_crstate);
4635 ssh->packet_dispatch[SSH1_SMSG_STDOUT_DATA] =
4636 ssh->packet_dispatch[SSH1_SMSG_STDERR_DATA] =
4637 ssh1_smsg_stdout_stderr_data;
4639 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION] =
4640 ssh1_msg_channel_open_confirmation;
4641 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_FAILURE] =
4642 ssh1_msg_channel_open_failure;
4643 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE] =
4644 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION] =
4645 ssh1_msg_channel_close;
4646 ssh->packet_dispatch[SSH1_MSG_CHANNEL_DATA] = ssh1_msg_channel_data;
4647 ssh->packet_dispatch[SSH1_SMSG_EXIT_STATUS] = ssh1_smsg_exit_status;
4649 if (ssh->cfg.agentfwd && agent_exists()) {
4650 logevent("Requesting agent forwarding");
4651 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
4655 if (pktin->type != SSH1_SMSG_SUCCESS
4656 && pktin->type != SSH1_SMSG_FAILURE) {
4657 bombout(("Protocol confusion"));
4659 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4660 logevent("Agent forwarding refused");
4662 logevent("Agent forwarding enabled");
4663 ssh->agentfwd_enabled = TRUE;
4664 ssh->packet_dispatch[SSH1_SMSG_AGENT_OPEN] = ssh1_smsg_agent_open;
4668 if (ssh->cfg.x11_forward) {
4669 char proto[20], data[64];
4670 logevent("Requesting X11 forwarding");
4671 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
4672 data, sizeof(data), ssh->cfg.x11_auth);
4673 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
4675 * Note that while we blank the X authentication data here, we don't
4676 * take any special action to blank the start of an X11 channel,
4677 * so using MIT-MAGIC-COOKIE-1 and actually opening an X connection
4678 * without having session blanking enabled is likely to leak your
4679 * cookie into the log.
4681 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
4682 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
4684 PKTT_PASSWORD, PKT_STR, data, PKTT_OTHER,
4685 PKT_INT, x11_get_screen_number(ssh->cfg.x11_display),
4688 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
4690 PKTT_PASSWORD, PKT_STR, data, PKTT_OTHER, PKT_END);
4695 if (pktin->type != SSH1_SMSG_SUCCESS
4696 && pktin->type != SSH1_SMSG_FAILURE) {
4697 bombout(("Protocol confusion"));
4699 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4700 logevent("X11 forwarding refused");
4702 logevent("X11 forwarding enabled");
4703 ssh->X11_fwd_enabled = TRUE;
4704 ssh->packet_dispatch[SSH1_SMSG_X11_OPEN] = ssh1_smsg_x11_open;
4708 ssh_setup_portfwd(ssh, &ssh->cfg);
4709 ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] = ssh1_msg_port_open;
4711 if (!ssh->cfg.nopty) {
4713 /* Unpick the terminal-speed string. */
4714 /* XXX perhaps we should allow no speeds to be sent. */
4715 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
4716 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
4717 /* Send the pty request. */
4718 pkt = ssh1_pkt_init(SSH1_CMSG_REQUEST_PTY);
4719 ssh_pkt_addstring(pkt, ssh->cfg.termtype);
4720 ssh_pkt_adduint32(pkt, ssh->term_height);
4721 ssh_pkt_adduint32(pkt, ssh->term_width);
4722 ssh_pkt_adduint32(pkt, 0); /* width in pixels */
4723 ssh_pkt_adduint32(pkt, 0); /* height in pixels */
4724 parse_ttymodes(ssh, ssh->cfg.ttymodes,
4725 ssh1_send_ttymode, (void *)pkt);
4726 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_ISPEED);
4727 ssh_pkt_adduint32(pkt, ssh->ispeed);
4728 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_OSPEED);
4729 ssh_pkt_adduint32(pkt, ssh->ospeed);
4730 ssh_pkt_addbyte(pkt, SSH_TTY_OP_END);
4732 ssh->state = SSH_STATE_INTERMED;
4736 if (pktin->type != SSH1_SMSG_SUCCESS
4737 && pktin->type != SSH1_SMSG_FAILURE) {
4738 bombout(("Protocol confusion"));
4740 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4741 c_write_str(ssh, "Server refused to allocate pty\r\n");
4742 ssh->editing = ssh->echoing = 1;
4744 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
4745 ssh->ospeed, ssh->ispeed);
4747 ssh->editing = ssh->echoing = 1;
4750 if (ssh->cfg.compression) {
4751 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
4755 if (pktin->type != SSH1_SMSG_SUCCESS
4756 && pktin->type != SSH1_SMSG_FAILURE) {
4757 bombout(("Protocol confusion"));
4759 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4760 c_write_str(ssh, "Server refused to compress\r\n");
4762 logevent("Started compression");
4763 ssh->v1_compressing = TRUE;
4764 ssh->cs_comp_ctx = zlib_compress_init();
4765 logevent("Initialised zlib (RFC1950) compression");
4766 ssh->sc_comp_ctx = zlib_decompress_init();
4767 logevent("Initialised zlib (RFC1950) decompression");
4771 * Start the shell or command.
4773 * Special case: if the first-choice command is an SSH-2
4774 * subsystem (hence not usable here) and the second choice
4775 * exists, we fall straight back to that.
4778 char *cmd = ssh->cfg.remote_cmd_ptr;
4780 if (!cmd) cmd = ssh->cfg.remote_cmd;
4782 if (ssh->cfg.ssh_subsys && ssh->cfg.remote_cmd_ptr2) {
4783 cmd = ssh->cfg.remote_cmd_ptr2;
4784 ssh->fallback_cmd = TRUE;
4787 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
4789 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
4790 logevent("Started session");
4793 ssh->state = SSH_STATE_SESSION;
4794 if (ssh->size_needed)
4795 ssh_size(ssh, ssh->term_width, ssh->term_height);
4796 if (ssh->eof_needed)
4797 ssh_special(ssh, TS_EOF);
4800 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
4802 ssh->channels = newtree234(ssh_channelcmp);
4806 * By this point, most incoming packets are already being
4807 * handled by the dispatch table, and we need only pay
4808 * attention to the unusual ones.
4813 if (pktin->type == SSH1_SMSG_SUCCESS) {
4814 /* may be from EXEC_SHELL on some servers */
4815 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4816 /* may be from EXEC_SHELL on some servers
4817 * if no pty is available or in other odd cases. Ignore */
4819 bombout(("Strange packet received: type %d", pktin->type));
4824 int len = min(inlen, 512);
4825 send_packet(ssh, SSH1_CMSG_STDIN_DATA, PKTT_DATA,
4826 PKT_INT, len, PKT_DATA, in, len,
4827 PKTT_OTHER, PKT_END);
4838 * Handle the top-level SSH-2 protocol.
4840 static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin)
4845 ssh_pkt_getstring(pktin, &msg, &msglen);
4846 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
4849 static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin)
4851 /* log reason code in disconnect message */
4855 ssh_pkt_getstring(pktin, &msg, &msglen);
4856 bombout(("Server sent disconnect message:\n\"%.*s\"", msglen, msg));
4859 static void ssh_msg_ignore(Ssh ssh, struct Packet *pktin)
4861 /* Do nothing, because we're ignoring it! Duhh. */
4864 static void ssh1_protocol_setup(Ssh ssh)
4869 * Most messages are handled by the coroutines.
4871 for (i = 0; i < 256; i++)
4872 ssh->packet_dispatch[i] = NULL;
4875 * These special message types we install handlers for.
4877 ssh->packet_dispatch[SSH1_MSG_DISCONNECT] = ssh1_msg_disconnect;
4878 ssh->packet_dispatch[SSH1_MSG_IGNORE] = ssh_msg_ignore;
4879 ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug;
4882 static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
4883 struct Packet *pktin)
4885 unsigned char *in=(unsigned char*)vin;
4886 if (ssh->state == SSH_STATE_CLOSED)
4889 if (pktin && ssh->packet_dispatch[pktin->type]) {
4890 ssh->packet_dispatch[pktin->type](ssh, pktin);
4894 if (!ssh->protocol_initial_phase_done) {
4895 if (do_ssh1_login(ssh, in, inlen, pktin))
4896 ssh->protocol_initial_phase_done = TRUE;
4901 do_ssh1_connection(ssh, in, inlen, pktin);
4905 * Utility routine for decoding comma-separated strings in KEXINIT.
4907 static int in_commasep_string(char *needle, char *haystack, int haylen)
4910 if (!needle || !haystack) /* protect against null pointers */
4912 needlen = strlen(needle);
4915 * Is it at the start of the string?
4917 if (haylen >= needlen && /* haystack is long enough */
4918 !memcmp(needle, haystack, needlen) && /* initial match */
4919 (haylen == needlen || haystack[needlen] == ',')
4920 /* either , or EOS follows */
4924 * If not, search for the next comma and resume after that.
4925 * If no comma found, terminate.
4927 while (haylen > 0 && *haystack != ',')
4928 haylen--, haystack++;
4931 haylen--, haystack++; /* skip over comma itself */
4936 * Similar routine for checking whether we have the first string in a list.
4938 static int first_in_commasep_string(char *needle, char *haystack, int haylen)
4941 if (!needle || !haystack) /* protect against null pointers */
4943 needlen = strlen(needle);
4945 * Is it at the start of the string?
4947 if (haylen >= needlen && /* haystack is long enough */
4948 !memcmp(needle, haystack, needlen) && /* initial match */
4949 (haylen == needlen || haystack[needlen] == ',')
4950 /* either , or EOS follows */
4958 * SSH-2 key creation method.
4960 static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H, char chr,
4961 unsigned char *keyspace)
4963 const struct ssh_hash *h = ssh->kex->hash;
4965 /* First hlen bytes. */
4967 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
4968 hash_mpint(h, s, K);
4969 h->bytes(s, H, h->hlen);
4970 h->bytes(s, &chr, 1);
4971 h->bytes(s, ssh->v2_session_id, ssh->v2_session_id_len);
4972 h->final(s, keyspace);
4973 /* Next hlen bytes. */
4975 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
4976 hash_mpint(h, s, K);
4977 h->bytes(s, H, h->hlen);
4978 h->bytes(s, keyspace, h->hlen);
4979 h->final(s, keyspace + h->hlen);
4983 * Handle the SSH-2 transport layer.
4985 static int do_ssh2_transport(Ssh ssh, void *vin, int inlen,
4986 struct Packet *pktin)
4988 unsigned char *in = (unsigned char *)vin;
4989 struct do_ssh2_transport_state {
4990 int nbits, pbits, warn_kex, warn_cscipher, warn_sccipher;
4991 Bignum p, g, e, f, K;
4994 int kex_init_value, kex_reply_value;
4995 const struct ssh_mac **maclist;
4997 const struct ssh2_cipher *cscipher_tobe;
4998 const struct ssh2_cipher *sccipher_tobe;
4999 const struct ssh_mac *csmac_tobe;
5000 const struct ssh_mac *scmac_tobe;
5001 const struct ssh_compress *cscomp_tobe;
5002 const struct ssh_compress *sccomp_tobe;
5003 char *hostkeydata, *sigdata, *keystr, *fingerprint;
5004 int hostkeylen, siglen;
5005 void *hkey; /* actual host key */
5006 unsigned char exchange_hash[32];
5007 int n_preferred_kex;
5008 const struct ssh_kexes *preferred_kex[KEX_MAX];
5009 int n_preferred_ciphers;
5010 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
5011 const struct ssh_compress *preferred_comp;
5012 int got_session_id, activated_authconn;
5013 struct Packet *pktout;
5018 crState(do_ssh2_transport_state);
5020 crBegin(ssh->do_ssh2_transport_crstate);
5022 s->cscipher_tobe = s->sccipher_tobe = NULL;
5023 s->csmac_tobe = s->scmac_tobe = NULL;
5024 s->cscomp_tobe = s->sccomp_tobe = NULL;
5026 s->got_session_id = s->activated_authconn = FALSE;
5029 * Be prepared to work around the buggy MAC problem.
5031 if (ssh->remote_bugs & BUG_SSH2_HMAC)
5032 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
5034 s->maclist = macs, s->nmacs = lenof(macs);
5037 ssh->pkt_ctx &= ~SSH2_PKTCTX_KEX_MASK;
5039 int i, j, commalist_started;
5042 * Set up the preferred key exchange. (NULL => warn below here)
5044 s->n_preferred_kex = 0;
5045 for (i = 0; i < KEX_MAX; i++) {
5046 switch (ssh->cfg.ssh_kexlist[i]) {
5048 s->preferred_kex[s->n_preferred_kex++] =
5049 &ssh_diffiehellman_gex;
5052 s->preferred_kex[s->n_preferred_kex++] =
5053 &ssh_diffiehellman_group14;
5056 s->preferred_kex[s->n_preferred_kex++] =
5057 &ssh_diffiehellman_group1;
5060 /* Flag for later. Don't bother if it's the last in
5062 if (i < KEX_MAX - 1) {
5063 s->preferred_kex[s->n_preferred_kex++] = NULL;
5070 * Set up the preferred ciphers. (NULL => warn below here)
5072 s->n_preferred_ciphers = 0;
5073 for (i = 0; i < CIPHER_MAX; i++) {
5074 switch (ssh->cfg.ssh_cipherlist[i]) {
5075 case CIPHER_BLOWFISH:
5076 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
5079 if (ssh->cfg.ssh2_des_cbc) {
5080 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
5084 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
5087 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
5089 case CIPHER_ARCFOUR:
5090 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_arcfour;
5093 /* Flag for later. Don't bother if it's the last in
5095 if (i < CIPHER_MAX - 1) {
5096 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
5103 * Set up preferred compression.
5105 if (ssh->cfg.compression)
5106 s->preferred_comp = &ssh_zlib;
5108 s->preferred_comp = &ssh_comp_none;
5111 * Enable queueing of outgoing auth- or connection-layer
5112 * packets while we are in the middle of a key exchange.
5114 ssh->queueing = TRUE;
5117 * Flag that KEX is in progress.
5119 ssh->kex_in_progress = TRUE;
5122 * Construct and send our key exchange packet.
5124 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT);
5125 for (i = 0; i < 16; i++)
5126 ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte());
5127 /* List key exchange algorithms. */
5128 ssh2_pkt_addstring_start(s->pktout);
5129 commalist_started = 0;
5130 for (i = 0; i < s->n_preferred_kex; i++) {
5131 const struct ssh_kexes *k = s->preferred_kex[i];
5132 if (!k) continue; /* warning flag */
5133 for (j = 0; j < k->nkexes; j++) {
5134 if (commalist_started)
5135 ssh2_pkt_addstring_str(s->pktout, ",");
5136 ssh2_pkt_addstring_str(s->pktout, k->list[j]->name);
5137 commalist_started = 1;
5140 /* List server host key algorithms. */
5141 ssh2_pkt_addstring_start(s->pktout);
5142 for (i = 0; i < lenof(hostkey_algs); i++) {
5143 ssh2_pkt_addstring_str(s->pktout, hostkey_algs[i]->name);
5144 if (i < lenof(hostkey_algs) - 1)
5145 ssh2_pkt_addstring_str(s->pktout, ",");
5147 /* List client->server encryption algorithms. */
5148 ssh2_pkt_addstring_start(s->pktout);
5149 commalist_started = 0;
5150 for (i = 0; i < s->n_preferred_ciphers; i++) {
5151 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5152 if (!c) continue; /* warning flag */
5153 for (j = 0; j < c->nciphers; j++) {
5154 if (commalist_started)
5155 ssh2_pkt_addstring_str(s->pktout, ",");
5156 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
5157 commalist_started = 1;
5160 /* List server->client encryption algorithms. */
5161 ssh2_pkt_addstring_start(s->pktout);
5162 commalist_started = 0;
5163 for (i = 0; i < s->n_preferred_ciphers; i++) {
5164 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5165 if (!c) continue; /* warning flag */
5166 for (j = 0; j < c->nciphers; j++) {
5167 if (commalist_started)
5168 ssh2_pkt_addstring_str(s->pktout, ",");
5169 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
5170 commalist_started = 1;
5173 /* List client->server MAC algorithms. */
5174 ssh2_pkt_addstring_start(s->pktout);
5175 for (i = 0; i < s->nmacs; i++) {
5176 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
5177 if (i < s->nmacs - 1)
5178 ssh2_pkt_addstring_str(s->pktout, ",");
5180 /* List server->client MAC algorithms. */
5181 ssh2_pkt_addstring_start(s->pktout);
5182 for (i = 0; i < s->nmacs; i++) {
5183 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
5184 if (i < s->nmacs - 1)
5185 ssh2_pkt_addstring_str(s->pktout, ",");
5187 /* List client->server compression algorithms. */
5188 ssh2_pkt_addstring_start(s->pktout);
5189 assert(lenof(compressions) > 1);
5190 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
5191 for (i = 0; i < lenof(compressions); i++) {
5192 const struct ssh_compress *c = compressions[i];
5193 if (c != s->preferred_comp) {
5194 ssh2_pkt_addstring_str(s->pktout, ",");
5195 ssh2_pkt_addstring_str(s->pktout, c->name);
5198 /* List server->client compression algorithms. */
5199 ssh2_pkt_addstring_start(s->pktout);
5200 assert(lenof(compressions) > 1);
5201 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
5202 for (i = 0; i < lenof(compressions); i++) {
5203 const struct ssh_compress *c = compressions[i];
5204 if (c != s->preferred_comp) {
5205 ssh2_pkt_addstring_str(s->pktout, ",");
5206 ssh2_pkt_addstring_str(s->pktout, c->name);
5209 /* List client->server languages. Empty list. */
5210 ssh2_pkt_addstring_start(s->pktout);
5211 /* List server->client languages. Empty list. */
5212 ssh2_pkt_addstring_start(s->pktout);
5213 /* First KEX packet does _not_ follow, because we're not that brave. */
5214 ssh2_pkt_addbool(s->pktout, FALSE);
5216 ssh2_pkt_adduint32(s->pktout, 0);
5219 s->our_kexinitlen = s->pktout->length - 5;
5220 s->our_kexinit = snewn(s->our_kexinitlen, unsigned char);
5221 memcpy(s->our_kexinit, s->pktout->data + 5, s->our_kexinitlen);
5223 ssh2_pkt_send_noqueue(ssh, s->pktout);
5229 * Now examine the other side's KEXINIT to see what we're up
5233 char *str, *preferred;
5236 if (pktin->type != SSH2_MSG_KEXINIT) {
5237 bombout(("expected key exchange packet from server"));
5241 ssh->hostkey = NULL;
5242 s->cscipher_tobe = NULL;
5243 s->sccipher_tobe = NULL;
5244 s->csmac_tobe = NULL;
5245 s->scmac_tobe = NULL;
5246 s->cscomp_tobe = NULL;
5247 s->sccomp_tobe = NULL;
5248 s->warn_kex = s->warn_cscipher = s->warn_sccipher = FALSE;
5250 pktin->savedpos += 16; /* skip garbage cookie */
5251 ssh_pkt_getstring(pktin, &str, &len); /* key exchange algorithms */
5254 for (i = 0; i < s->n_preferred_kex; i++) {
5255 const struct ssh_kexes *k = s->preferred_kex[i];
5259 for (j = 0; j < k->nkexes; j++) {
5260 if (!preferred) preferred = k->list[j]->name;
5261 if (in_commasep_string(k->list[j]->name, str, len)) {
5262 ssh->kex = k->list[j];
5271 bombout(("Couldn't agree a key exchange algorithm (available: %s)",
5272 str ? str : "(null)"));
5276 * Note that the server's guess is considered wrong if it doesn't match
5277 * the first algorithm in our list, even if it's still the algorithm
5280 s->guessok = first_in_commasep_string(preferred, str, len);
5281 ssh_pkt_getstring(pktin, &str, &len); /* host key algorithms */
5282 for (i = 0; i < lenof(hostkey_algs); i++) {
5283 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
5284 ssh->hostkey = hostkey_algs[i];
5288 s->guessok = s->guessok &&
5289 first_in_commasep_string(hostkey_algs[0]->name, str, len);
5290 ssh_pkt_getstring(pktin, &str, &len); /* client->server cipher */
5291 for (i = 0; i < s->n_preferred_ciphers; i++) {
5292 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5294 s->warn_cscipher = TRUE;
5296 for (j = 0; j < c->nciphers; j++) {
5297 if (in_commasep_string(c->list[j]->name, str, len)) {
5298 s->cscipher_tobe = c->list[j];
5303 if (s->cscipher_tobe)
5306 if (!s->cscipher_tobe) {
5307 bombout(("Couldn't agree a client-to-server cipher (available: %s)",
5308 str ? str : "(null)"));
5312 ssh_pkt_getstring(pktin, &str, &len); /* server->client cipher */
5313 for (i = 0; i < s->n_preferred_ciphers; i++) {
5314 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5316 s->warn_sccipher = TRUE;
5318 for (j = 0; j < c->nciphers; j++) {
5319 if (in_commasep_string(c->list[j]->name, str, len)) {
5320 s->sccipher_tobe = c->list[j];
5325 if (s->sccipher_tobe)
5328 if (!s->sccipher_tobe) {
5329 bombout(("Couldn't agree a server-to-client cipher (available: %s)",
5330 str ? str : "(null)"));
5334 ssh_pkt_getstring(pktin, &str, &len); /* client->server mac */
5335 for (i = 0; i < s->nmacs; i++) {
5336 if (in_commasep_string(s->maclist[i]->name, str, len)) {
5337 s->csmac_tobe = s->maclist[i];
5341 ssh_pkt_getstring(pktin, &str, &len); /* server->client mac */
5342 for (i = 0; i < s->nmacs; i++) {
5343 if (in_commasep_string(s->maclist[i]->name, str, len)) {
5344 s->scmac_tobe = s->maclist[i];
5348 ssh_pkt_getstring(pktin, &str, &len); /* client->server compression */
5349 for (i = 0; i < lenof(compressions) + 1; i++) {
5350 const struct ssh_compress *c =
5351 i == 0 ? s->preferred_comp : compressions[i - 1];
5352 if (in_commasep_string(c->name, str, len)) {
5357 ssh_pkt_getstring(pktin, &str, &len); /* server->client compression */
5358 for (i = 0; i < lenof(compressions) + 1; i++) {
5359 const struct ssh_compress *c =
5360 i == 0 ? s->preferred_comp : compressions[i - 1];
5361 if (in_commasep_string(c->name, str, len)) {
5366 ssh_pkt_getstring(pktin, &str, &len); /* client->server language */
5367 ssh_pkt_getstring(pktin, &str, &len); /* server->client language */
5368 s->ignorepkt = ssh2_pkt_getbool(pktin) && !s->guessok;
5371 ssh_set_frozen(ssh, 1);
5372 s->dlgret = askalg(ssh->frontend, "key-exchange algorithm",
5374 ssh_dialog_callback, ssh);
5375 if (s->dlgret < 0) {
5379 bombout(("Unexpected data from server while"
5380 " waiting for user response"));
5383 } while (pktin || inlen > 0);
5384 s->dlgret = ssh->user_response;
5386 ssh_set_frozen(ssh, 0);
5387 if (s->dlgret == 0) {
5388 ssh_disconnect(ssh, "User aborted at kex warning", NULL,
5394 if (s->warn_cscipher) {
5395 ssh_set_frozen(ssh, 1);
5396 s->dlgret = askalg(ssh->frontend,
5397 "client-to-server cipher",
5398 s->cscipher_tobe->name,
5399 ssh_dialog_callback, ssh);
5400 if (s->dlgret < 0) {
5404 bombout(("Unexpected data from server while"
5405 " waiting for user response"));
5408 } while (pktin || inlen > 0);
5409 s->dlgret = ssh->user_response;
5411 ssh_set_frozen(ssh, 0);
5412 if (s->dlgret == 0) {
5413 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
5419 if (s->warn_sccipher) {
5420 ssh_set_frozen(ssh, 1);
5421 s->dlgret = askalg(ssh->frontend,
5422 "server-to-client cipher",
5423 s->sccipher_tobe->name,
5424 ssh_dialog_callback, ssh);
5425 if (s->dlgret < 0) {
5429 bombout(("Unexpected data from server while"
5430 " waiting for user response"));
5433 } while (pktin || inlen > 0);
5434 s->dlgret = ssh->user_response;
5436 ssh_set_frozen(ssh, 0);
5437 if (s->dlgret == 0) {
5438 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
5444 ssh->exhash = ssh->kex->hash->init();
5445 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_c, strlen(ssh->v_c));
5446 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_s, strlen(ssh->v_s));
5447 hash_string(ssh->kex->hash, ssh->exhash,
5448 s->our_kexinit, s->our_kexinitlen);
5449 sfree(s->our_kexinit);
5450 if (pktin->length > 5)
5451 hash_string(ssh->kex->hash, ssh->exhash,
5452 pktin->data + 5, pktin->length - 5);
5454 if (s->ignorepkt) /* first_kex_packet_follows */
5455 crWaitUntil(pktin); /* Ignore packet */
5459 * Work out the number of bits of key we will need from the key
5460 * exchange. We start with the maximum key length of either
5466 csbits = s->cscipher_tobe->keylen;
5467 scbits = s->sccipher_tobe->keylen;
5468 s->nbits = (csbits > scbits ? csbits : scbits);
5470 /* The keys only have hlen-bit entropy, since they're based on
5471 * a hash. So cap the key size at hlen bits. */
5472 if (s->nbits > ssh->kex->hash->hlen * 8)
5473 s->nbits = ssh->kex->hash->hlen * 8;
5476 * If we're doing Diffie-Hellman group exchange, start by
5477 * requesting a group.
5479 if (!ssh->kex->pdata) {
5480 logevent("Doing Diffie-Hellman group exchange");
5481 ssh->pkt_ctx |= SSH2_PKTCTX_DHGEX;
5483 * Work out how big a DH group we will need to allow that
5486 s->pbits = 512 << ((s->nbits - 1) / 64);
5487 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
5488 ssh2_pkt_adduint32(s->pktout, s->pbits);
5489 ssh2_pkt_send_noqueue(ssh, s->pktout);
5492 if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) {
5493 bombout(("expected key exchange group packet from server"));
5496 s->p = ssh2_pkt_getmp(pktin);
5497 s->g = ssh2_pkt_getmp(pktin);
5498 if (!s->p || !s->g) {
5499 bombout(("unable to read mp-ints from incoming group packet"));
5502 ssh->kex_ctx = dh_setup_gex(s->p, s->g);
5503 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
5504 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
5506 ssh->pkt_ctx |= SSH2_PKTCTX_DHGROUP;
5507 ssh->kex_ctx = dh_setup_group(ssh->kex);
5508 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
5509 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
5510 logeventf(ssh, "Using Diffie-Hellman with standard group \"%s\"",
5511 ssh->kex->groupname);
5514 logevent("Doing Diffie-Hellman key exchange");
5516 * Now generate and send e for Diffie-Hellman.
5518 set_busy_status(ssh->frontend, BUSY_CPU); /* this can take a while */
5519 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
5520 s->pktout = ssh2_pkt_init(s->kex_init_value);
5521 ssh2_pkt_addmp(s->pktout, s->e);
5522 ssh2_pkt_send_noqueue(ssh, s->pktout);
5524 set_busy_status(ssh->frontend, BUSY_WAITING); /* wait for server */
5526 if (pktin->type != s->kex_reply_value) {
5527 bombout(("expected key exchange reply packet from server"));
5530 set_busy_status(ssh->frontend, BUSY_CPU); /* cogitate */
5531 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
5532 s->f = ssh2_pkt_getmp(pktin);
5534 bombout(("unable to parse key exchange reply packet"));
5537 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
5539 s->K = dh_find_K(ssh->kex_ctx, s->f);
5541 /* We assume everything from now on will be quick, and it might
5542 * involve user interaction. */
5543 set_busy_status(ssh->frontend, BUSY_NOT);
5545 hash_string(ssh->kex->hash, ssh->exhash, s->hostkeydata, s->hostkeylen);
5546 if (!ssh->kex->pdata) {
5547 hash_uint32(ssh->kex->hash, ssh->exhash, s->pbits);
5548 hash_mpint(ssh->kex->hash, ssh->exhash, s->p);
5549 hash_mpint(ssh->kex->hash, ssh->exhash, s->g);
5551 hash_mpint(ssh->kex->hash, ssh->exhash, s->e);
5552 hash_mpint(ssh->kex->hash, ssh->exhash, s->f);
5553 hash_mpint(ssh->kex->hash, ssh->exhash, s->K);
5554 assert(ssh->kex->hash->hlen <= sizeof(s->exchange_hash));
5555 ssh->kex->hash->final(ssh->exhash, s->exchange_hash);
5557 dh_cleanup(ssh->kex_ctx);
5558 ssh->kex_ctx = NULL;
5561 debug(("Exchange hash is:\n"));
5562 dmemdump(s->exchange_hash, ssh->kex->hash->hlen);
5565 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
5567 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
5568 (char *)s->exchange_hash,
5569 ssh->kex->hash->hlen)) {
5570 bombout(("Server's host key did not match the signature supplied"));
5575 * Authenticate remote host: verify host key. (We've already
5576 * checked the signature of the exchange hash.)
5578 s->keystr = ssh->hostkey->fmtkey(s->hkey);
5579 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
5580 ssh_set_frozen(ssh, 1);
5581 s->dlgret = verify_ssh_host_key(ssh->frontend,
5582 ssh->savedhost, ssh->savedport,
5583 ssh->hostkey->keytype, s->keystr,
5585 ssh_dialog_callback, ssh);
5586 if (s->dlgret < 0) {
5590 bombout(("Unexpected data from server while waiting"
5591 " for user host key response"));
5594 } while (pktin || inlen > 0);
5595 s->dlgret = ssh->user_response;
5597 ssh_set_frozen(ssh, 0);
5598 if (s->dlgret == 0) {
5599 ssh_disconnect(ssh, "User aborted at host key verification", NULL,
5603 if (!s->got_session_id) { /* don't bother logging this in rekeys */
5604 logevent("Host key fingerprint is:");
5605 logevent(s->fingerprint);
5607 sfree(s->fingerprint);
5609 ssh->hostkey->freekey(s->hkey);
5612 * The exchange hash from the very first key exchange is also
5613 * the session id, used in session key construction and
5616 if (!s->got_session_id) {
5617 assert(sizeof(s->exchange_hash) <= sizeof(ssh->v2_session_id));
5618 memcpy(ssh->v2_session_id, s->exchange_hash,
5619 sizeof(s->exchange_hash));
5620 ssh->v2_session_id_len = ssh->kex->hash->hlen;
5621 assert(ssh->v2_session_id_len <= sizeof(ssh->v2_session_id));
5622 s->got_session_id = TRUE;
5626 * Send SSH2_MSG_NEWKEYS.
5628 s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS);
5629 ssh2_pkt_send_noqueue(ssh, s->pktout);
5630 ssh->outgoing_data_size = 0; /* start counting from here */
5633 * We've sent client NEWKEYS, so create and initialise
5634 * client-to-server session keys.
5636 if (ssh->cs_cipher_ctx)
5637 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
5638 ssh->cscipher = s->cscipher_tobe;
5639 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
5641 if (ssh->cs_mac_ctx)
5642 ssh->csmac->free_context(ssh->cs_mac_ctx);
5643 ssh->csmac = s->csmac_tobe;
5644 ssh->cs_mac_ctx = ssh->csmac->make_context();
5646 if (ssh->cs_comp_ctx)
5647 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
5648 ssh->cscomp = s->cscomp_tobe;
5649 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
5652 * Set IVs on client-to-server keys. Here we use the exchange
5653 * hash from the _first_ key exchange.
5656 unsigned char keyspace[40];
5657 ssh2_mkkey(ssh,s->K,s->exchange_hash,'C',keyspace);
5658 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
5659 ssh2_mkkey(ssh,s->K,s->exchange_hash,'A',keyspace);
5660 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
5661 ssh2_mkkey(ssh,s->K,s->exchange_hash,'E',keyspace);
5662 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
5665 logeventf(ssh, "Initialised %.200s client->server encryption",
5666 ssh->cscipher->text_name);
5667 logeventf(ssh, "Initialised %.200s client->server MAC algorithm",
5668 ssh->csmac->text_name);
5669 if (ssh->cscomp->text_name)
5670 logeventf(ssh, "Initialised %s compression",
5671 ssh->cscomp->text_name);
5674 * Now our end of the key exchange is complete, we can send all
5675 * our queued higher-layer packets.
5677 ssh->queueing = FALSE;
5678 ssh2_pkt_queuesend(ssh);
5681 * Expect SSH2_MSG_NEWKEYS from server.
5684 if (pktin->type != SSH2_MSG_NEWKEYS) {
5685 bombout(("expected new-keys packet from server"));
5688 ssh->incoming_data_size = 0; /* start counting from here */
5691 * We've seen server NEWKEYS, so create and initialise
5692 * server-to-client session keys.
5694 if (ssh->sc_cipher_ctx)
5695 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
5696 ssh->sccipher = s->sccipher_tobe;
5697 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
5699 if (ssh->sc_mac_ctx)
5700 ssh->scmac->free_context(ssh->sc_mac_ctx);
5701 ssh->scmac = s->scmac_tobe;
5702 ssh->sc_mac_ctx = ssh->scmac->make_context();
5704 if (ssh->sc_comp_ctx)
5705 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
5706 ssh->sccomp = s->sccomp_tobe;
5707 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
5710 * Set IVs on server-to-client keys. Here we use the exchange
5711 * hash from the _first_ key exchange.
5714 unsigned char keyspace[40];
5715 ssh2_mkkey(ssh,s->K,s->exchange_hash,'D',keyspace);
5716 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
5717 ssh2_mkkey(ssh,s->K,s->exchange_hash,'B',keyspace);
5718 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
5719 ssh2_mkkey(ssh,s->K,s->exchange_hash,'F',keyspace);
5720 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
5722 logeventf(ssh, "Initialised %.200s server->client encryption",
5723 ssh->sccipher->text_name);
5724 logeventf(ssh, "Initialised %.200s server->client MAC algorithm",
5725 ssh->scmac->text_name);
5726 if (ssh->sccomp->text_name)
5727 logeventf(ssh, "Initialised %s decompression",
5728 ssh->sccomp->text_name);
5731 * Free key exchange data.
5735 if (!ssh->kex->pdata) {
5741 * Key exchange is over. Loop straight back round if we have a
5742 * deferred rekey reason.
5744 if (ssh->deferred_rekey_reason) {
5745 logevent(ssh->deferred_rekey_reason);
5747 ssh->deferred_rekey_reason = NULL;
5748 goto begin_key_exchange;
5752 * Otherwise, schedule a timer for our next rekey.
5754 ssh->kex_in_progress = FALSE;
5755 ssh->last_rekey = GETTICKCOUNT();
5756 if (ssh->cfg.ssh_rekey_time != 0)
5757 ssh->next_rekey = schedule_timer(ssh->cfg.ssh_rekey_time*60*TICKSPERSEC,
5761 * If this is the first key exchange phase, we must pass the
5762 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
5763 * wants to see it but because it will need time to initialise
5764 * itself before it sees an actual packet. In subsequent key
5765 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
5766 * it would only confuse the layer above.
5768 if (s->activated_authconn) {
5771 s->activated_authconn = TRUE;
5774 * Now we're encrypting. Begin returning 1 to the protocol main
5775 * function so that other things can run on top of the
5776 * transport. If we ever see a KEXINIT, we must go back to the
5779 * We _also_ go back to the start if we see pktin==NULL and
5780 * inlen==-1, because this is a special signal meaning
5781 * `initiate client-driven rekey', and `in' contains a message
5782 * giving the reason for the rekey.
5784 while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) ||
5785 (!pktin && inlen == -1))) {
5790 logevent("Server initiated key re-exchange");
5793 * Special case: if the server bug is set that doesn't
5794 * allow rekeying, we give a different log message and
5795 * continue waiting. (If such a server _initiates_ a rekey,
5796 * we process it anyway!)
5798 if ((ssh->remote_bugs & BUG_SSH2_REKEY)) {
5799 logeventf(ssh, "Server bug prevents key re-exchange (%s)",
5801 /* Reset the counters, so that at least this message doesn't
5802 * hit the event log _too_ often. */
5803 ssh->outgoing_data_size = 0;
5804 ssh->incoming_data_size = 0;
5805 if (ssh->cfg.ssh_rekey_time != 0) {
5807 schedule_timer(ssh->cfg.ssh_rekey_time*60*TICKSPERSEC,
5810 goto wait_for_rekey; /* this is utterly horrid */
5812 logeventf(ssh, "Initiating key re-exchange (%s)", (char *)in);
5815 goto begin_key_exchange;
5821 * Add data to an SSH-2 channel output buffer.
5823 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
5826 bufchain_add(&c->v.v2.outbuffer, buf, len);
5830 * Attempt to send data on an SSH-2 channel.
5832 static int ssh2_try_send(struct ssh_channel *c)
5835 struct Packet *pktout;
5837 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
5840 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
5841 if ((unsigned)len > c->v.v2.remwindow)
5842 len = c->v.v2.remwindow;
5843 if ((unsigned)len > c->v.v2.remmaxpkt)
5844 len = c->v.v2.remmaxpkt;
5845 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
5846 ssh2_pkt_adduint32(pktout, c->remoteid);
5847 dont_log_data(ssh, pktout, PKTLOG_OMIT);
5848 ssh2_pkt_addstring_start(pktout);
5849 ssh2_pkt_addstring_data(pktout, data, len);
5850 end_log_omission(ssh, pktout);
5851 ssh2_pkt_send(ssh, pktout);
5852 bufchain_consume(&c->v.v2.outbuffer, len);
5853 c->v.v2.remwindow -= len;
5857 * After having sent as much data as we can, return the amount
5860 return bufchain_size(&c->v.v2.outbuffer);
5863 static void ssh2_try_send_and_unthrottle(struct ssh_channel *c)
5867 return; /* don't send on closing channels */
5868 bufsize = ssh2_try_send(c);
5871 case CHAN_MAINSESSION:
5872 /* stdin need not receive an unthrottle
5873 * notification since it will be polled */
5876 x11_unthrottle(c->u.x11.s);
5879 /* agent sockets are request/response and need no
5880 * buffer management */
5883 pfd_unthrottle(c->u.pfd.s);
5890 * Potentially enlarge the window on an SSH-2 channel.
5892 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
5897 * Never send WINDOW_ADJUST for a channel that the remote side
5898 * already thinks it's closed; there's no point, since it won't
5899 * be sending any more data anyway.
5905 * Only send a WINDOW_ADJUST if there's significantly more window
5906 * available than the other end thinks there is. This saves us
5907 * sending a WINDOW_ADJUST for every character in a shell session.
5909 * "Significant" is arbitrarily defined as half the window size.
5911 if (newwin > c->v.v2.locwindow * 2) {
5912 struct Packet *pktout;
5914 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5915 ssh2_pkt_adduint32(pktout, c->remoteid);
5916 ssh2_pkt_adduint32(pktout, newwin - c->v.v2.locwindow);
5917 ssh2_pkt_send(ssh, pktout);
5918 c->v.v2.locwindow = newwin;
5922 static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin)
5924 unsigned i = ssh_pkt_getuint32(pktin);
5925 struct ssh_channel *c;
5926 c = find234(ssh->channels, &i, ssh_channelfind);
5927 if (c && !c->closes) {
5928 c->v.v2.remwindow += ssh_pkt_getuint32(pktin);
5929 ssh2_try_send_and_unthrottle(c);
5933 static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin)
5937 unsigned i = ssh_pkt_getuint32(pktin);
5938 struct ssh_channel *c;
5939 c = find234(ssh->channels, &i, ssh_channelfind);
5941 return; /* nonexistent channel */
5942 if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
5943 ssh_pkt_getuint32(pktin) != SSH2_EXTENDED_DATA_STDERR)
5944 return; /* extended but not stderr */
5945 ssh_pkt_getstring(pktin, &data, &length);
5948 c->v.v2.locwindow -= length;
5950 case CHAN_MAINSESSION:
5952 from_backend(ssh->frontend, pktin->type ==
5953 SSH2_MSG_CHANNEL_EXTENDED_DATA,
5957 bufsize = x11_send(c->u.x11.s, data, length);
5960 bufsize = pfd_send(c->u.pfd.s, data, length);
5963 while (length > 0) {
5964 if (c->u.a.lensofar < 4) {
5965 unsigned int l = min(4 - c->u.a.lensofar, length);
5966 memcpy(c->u.a.msglen + c->u.a.lensofar,
5970 c->u.a.lensofar += l;
5972 if (c->u.a.lensofar == 4) {
5974 4 + GET_32BIT(c->u.a.msglen);
5975 c->u.a.message = snewn(c->u.a.totallen,
5977 memcpy(c->u.a.message, c->u.a.msglen, 4);
5979 if (c->u.a.lensofar >= 4 && length > 0) {
5981 min(c->u.a.totallen - c->u.a.lensofar,
5983 memcpy(c->u.a.message + c->u.a.lensofar,
5987 c->u.a.lensofar += l;
5989 if (c->u.a.lensofar == c->u.a.totallen) {
5992 if (agent_query(c->u.a.message,
5995 ssh_agentf_callback, c))
5996 ssh_agentf_callback(c, reply, replylen);
5997 sfree(c->u.a.message);
5998 c->u.a.lensofar = 0;
6005 * If we are not buffering too much data,
6006 * enlarge the window again at the remote side.
6008 if (bufsize < OUR_V2_WINSIZE)
6009 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
6013 static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin)
6015 unsigned i = ssh_pkt_getuint32(pktin);
6016 struct ssh_channel *c;
6018 c = find234(ssh->channels, &i, ssh_channelfind);
6020 return; /* nonexistent channel */
6022 if (c->type == CHAN_X11) {
6024 * Remote EOF on an X11 channel means we should
6025 * wrap up and close the channel ourselves.
6027 x11_close(c->u.x11.s);
6029 } else if (c->type == CHAN_AGENT) {
6031 } else if (c->type == CHAN_SOCKDATA) {
6032 pfd_close(c->u.pfd.s);
6037 static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin)
6039 unsigned i = ssh_pkt_getuint32(pktin);
6040 struct ssh_channel *c;
6041 struct Packet *pktout;
6043 c = find234(ssh->channels, &i, ssh_channelfind);
6044 if (!c || c->halfopen) {
6045 bombout(("Received CHANNEL_CLOSE for %s channel %d\n",
6046 c ? "half-open" : "nonexistent", i));
6049 /* Do pre-close processing on the channel. */
6051 case CHAN_MAINSESSION:
6052 ssh->mainchan = NULL;
6053 update_specials_menu(ssh->frontend);
6056 if (c->u.x11.s != NULL)
6057 x11_close(c->u.x11.s);
6064 if (c->u.pfd.s != NULL)
6065 pfd_close(c->u.pfd.s);
6069 if (c->closes == 0) {
6070 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
6071 ssh2_pkt_adduint32(pktout, c->remoteid);
6072 ssh2_pkt_send(ssh, pktout);
6074 del234(ssh->channels, c);
6075 bufchain_clear(&c->v.v2.outbuffer);
6079 * See if that was the last channel left open.
6080 * (This is only our termination condition if we're
6081 * not running in -N mode.)
6083 if (!ssh->cfg.ssh_no_shell && count234(ssh->channels) == 0) {
6085 * We used to send SSH_MSG_DISCONNECT here,
6086 * because I'd believed that _every_ conforming
6087 * SSH-2 connection had to end with a disconnect
6088 * being sent by at least one side; apparently
6089 * I was wrong and it's perfectly OK to
6090 * unceremoniously slam the connection shut
6091 * when you're done, and indeed OpenSSH feels
6092 * this is more polite than sending a
6093 * DISCONNECT. So now we don't.
6095 ssh_disconnect(ssh, "All channels closed", NULL, 0, TRUE);
6099 static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
6101 unsigned i = ssh_pkt_getuint32(pktin);
6102 struct ssh_channel *c;
6103 struct Packet *pktout;
6105 c = find234(ssh->channels, &i, ssh_channelfind);
6107 return; /* nonexistent channel */
6108 if (c->type != CHAN_SOCKDATA_DORMANT)
6109 return; /* dunno why they're confirming this */
6110 c->remoteid = ssh_pkt_getuint32(pktin);
6111 c->halfopen = FALSE;
6112 c->type = CHAN_SOCKDATA;
6113 c->v.v2.remwindow = ssh_pkt_getuint32(pktin);
6114 c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
6116 pfd_confirm(c->u.pfd.s);
6119 * We have a pending close on this channel,
6120 * which we decided on before the server acked
6121 * the channel open. So now we know the
6122 * remoteid, we can close it again.
6124 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
6125 ssh2_pkt_adduint32(pktout, c->remoteid);
6126 ssh2_pkt_send(ssh, pktout);
6130 static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
6132 static const char *const reasons[] = {
6133 "<unknown reason code>",
6134 "Administratively prohibited",
6136 "Unknown channel type",
6137 "Resource shortage",
6139 unsigned i = ssh_pkt_getuint32(pktin);
6140 unsigned reason_code;
6141 char *reason_string;
6143 struct ssh_channel *c;
6144 c = find234(ssh->channels, &i, ssh_channelfind);
6146 return; /* nonexistent channel */
6147 if (c->type != CHAN_SOCKDATA_DORMANT)
6148 return; /* dunno why they're failing this */
6150 reason_code = ssh_pkt_getuint32(pktin);
6151 if (reason_code >= lenof(reasons))
6152 reason_code = 0; /* ensure reasons[reason_code] in range */
6153 ssh_pkt_getstring(pktin, &reason_string, &reason_length);
6154 logeventf(ssh, "Forwarded connection refused by server: %s [%.*s]",
6155 reasons[reason_code], reason_length, reason_string);
6157 pfd_close(c->u.pfd.s);
6159 del234(ssh->channels, c);
6163 static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin)
6167 int typelen, want_reply;
6168 int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */
6169 struct ssh_channel *c;
6170 struct Packet *pktout;
6172 localid = ssh_pkt_getuint32(pktin);
6173 ssh_pkt_getstring(pktin, &type, &typelen);
6174 want_reply = ssh2_pkt_getbool(pktin);
6177 * First, check that the channel exists. Otherwise,
6178 * we can instantly disconnect with a rude message.
6180 c = find234(ssh->channels, &localid, ssh_channelfind);
6182 char *buf = dupprintf("Received channel request for nonexistent"
6183 " channel %d", localid);
6184 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
6190 * Having got the channel number, we now look at
6191 * the request type string to see if it's something
6194 if (c == ssh->mainchan) {
6196 * We recognise "exit-status" and "exit-signal" on
6197 * the primary channel.
6199 if (typelen == 11 &&
6200 !memcmp(type, "exit-status", 11)) {
6202 ssh->exitcode = ssh_pkt_getuint32(pktin);
6203 logeventf(ssh, "Server sent command exit status %d",
6205 reply = SSH2_MSG_CHANNEL_SUCCESS;
6207 } else if (typelen == 11 &&
6208 !memcmp(type, "exit-signal", 11)) {
6210 int is_plausible = TRUE, is_int = FALSE;
6211 char *fmt_sig = "", *fmt_msg = "";
6213 int msglen = 0, core = FALSE;
6214 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
6215 * provide an `int' for the signal, despite its
6216 * having been a `string' in the drafts since at
6217 * least 2001. (Fixed in session.c 1.147.) Try to
6218 * infer which we can safely parse it as. */
6220 unsigned char *p = pktin->body +
6222 long len = pktin->length - pktin->savedpos;
6223 unsigned long num = GET_32BIT(p); /* what is it? */
6224 /* If it's 0, it hardly matters; assume string */
6228 int maybe_int = FALSE, maybe_str = FALSE;
6229 #define CHECK_HYPOTHESIS(offset, result) \
6232 if (q >= 0 && q+4 <= len) { \
6233 q = q + 4 + GET_32BIT(p+q); \
6234 if (q >= 0 && q+4 <= len && \
6235 ((q = q + 4 + GET_32BIT(p+q))!= 0) && q == len) \
6239 CHECK_HYPOTHESIS(4+1, maybe_int);
6240 CHECK_HYPOTHESIS(4+num+1, maybe_str);
6241 #undef CHECK_HYPOTHESIS
6242 if (maybe_int && !maybe_str)
6244 else if (!maybe_int && maybe_str)
6247 /* Crikey. Either or neither. Panic. */
6248 is_plausible = FALSE;
6253 /* Old non-standard OpenSSH. */
6254 int signum = ssh_pkt_getuint32(pktin);
6255 fmt_sig = dupprintf(" %d", signum);
6257 /* As per the drafts. */
6260 ssh_pkt_getstring(pktin, &sig, &siglen);
6261 /* Signal name isn't supposed to be blank, but
6262 * let's cope gracefully if it is. */
6264 fmt_sig = dupprintf(" \"%.*s\"",
6268 core = ssh2_pkt_getbool(pktin);
6269 ssh_pkt_getstring(pktin, &msg, &msglen);
6271 fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg);
6273 /* ignore lang tag */
6274 } /* else don't attempt to parse */
6275 logeventf(ssh, "Server exited on signal%s%s%s",
6276 fmt_sig, core ? " (core dumped)" : "",
6278 if (*fmt_sig) sfree(fmt_sig);
6279 if (*fmt_msg) sfree(fmt_msg);
6280 reply = SSH2_MSG_CHANNEL_SUCCESS;
6285 * This is a channel request we don't know
6286 * about, so we now either ignore the request
6287 * or respond with CHANNEL_FAILURE, depending
6290 reply = SSH2_MSG_CHANNEL_FAILURE;
6293 pktout = ssh2_pkt_init(reply);
6294 ssh2_pkt_adduint32(pktout, c->remoteid);
6295 ssh2_pkt_send(ssh, pktout);
6299 static void ssh2_msg_global_request(Ssh ssh, struct Packet *pktin)
6302 int typelen, want_reply;
6303 struct Packet *pktout;
6305 ssh_pkt_getstring(pktin, &type, &typelen);
6306 want_reply = ssh2_pkt_getbool(pktin);
6309 * We currently don't support any global requests
6310 * at all, so we either ignore the request or
6311 * respond with REQUEST_FAILURE, depending on
6315 pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
6316 ssh2_pkt_send(ssh, pktout);
6320 static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin)
6328 struct ssh_channel *c;
6329 unsigned remid, winsize, pktsize;
6330 struct Packet *pktout;
6332 ssh_pkt_getstring(pktin, &type, &typelen);
6333 c = snew(struct ssh_channel);
6336 remid = ssh_pkt_getuint32(pktin);
6337 winsize = ssh_pkt_getuint32(pktin);
6338 pktsize = ssh_pkt_getuint32(pktin);
6340 if (typelen == 3 && !memcmp(type, "x11", 3)) {
6343 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
6344 addrstr = snewn(peeraddrlen+1, char);
6345 memcpy(addrstr, peeraddr, peeraddrlen);
6346 addrstr[peeraddrlen] = '\0';
6347 peerport = ssh_pkt_getuint32(pktin);
6349 logeventf(ssh, "Received X11 connect request from %s:%d",
6352 if (!ssh->X11_fwd_enabled)
6353 error = "X11 forwarding is not enabled";
6354 else if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
6355 ssh->x11auth, addrstr, peerport,
6356 &ssh->cfg) != NULL) {
6357 error = "Unable to open an X11 connection";
6359 logevent("Opening X11 forward connection succeeded");
6364 } else if (typelen == 15 &&
6365 !memcmp(type, "forwarded-tcpip", 15)) {
6366 struct ssh_rportfwd pf, *realpf;
6369 ssh_pkt_getstring(pktin, &dummy, &dummylen);/* skip address */
6370 pf.sport = ssh_pkt_getuint32(pktin);
6371 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
6372 peerport = ssh_pkt_getuint32(pktin);
6373 realpf = find234(ssh->rportfwds, &pf, NULL);
6374 logeventf(ssh, "Received remote port %d open request "
6375 "from %s:%d", pf.sport, peeraddr, peerport);
6376 if (realpf == NULL) {
6377 error = "Remote port is not recognised";
6379 const char *e = pfd_newconnect(&c->u.pfd.s,
6383 realpf->pfrec->addressfamily);
6384 logeventf(ssh, "Attempting to forward remote port to "
6385 "%s:%d", realpf->dhost, realpf->dport);
6387 logeventf(ssh, "Port open failed: %s", e);
6388 error = "Port open failed";
6390 logevent("Forwarded port opened successfully");
6391 c->type = CHAN_SOCKDATA;
6394 } else if (typelen == 22 &&
6395 !memcmp(type, "auth-agent@openssh.com", 22)) {
6396 if (!ssh->agentfwd_enabled)
6397 error = "Agent forwarding is not enabled";
6399 c->type = CHAN_AGENT; /* identify channel type */
6400 c->u.a.lensofar = 0;
6403 error = "Unsupported channel type requested";
6406 c->remoteid = remid;
6407 c->halfopen = FALSE;
6409 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
6410 ssh2_pkt_adduint32(pktout, c->remoteid);
6411 ssh2_pkt_adduint32(pktout, SSH2_OPEN_CONNECT_FAILED);
6412 ssh2_pkt_addstring(pktout, error);
6413 ssh2_pkt_addstring(pktout, "en"); /* language tag */
6414 ssh2_pkt_send(ssh, pktout);
6415 logeventf(ssh, "Rejected channel open: %s", error);
6418 c->localid = alloc_channel_id(ssh);
6420 c->v.v2.locwindow = OUR_V2_WINSIZE;
6421 c->v.v2.remwindow = winsize;
6422 c->v.v2.remmaxpkt = pktsize;
6423 bufchain_init(&c->v.v2.outbuffer);
6424 add234(ssh->channels, c);
6425 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
6426 ssh2_pkt_adduint32(pktout, c->remoteid);
6427 ssh2_pkt_adduint32(pktout, c->localid);
6428 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);
6429 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
6430 ssh2_pkt_send(ssh, pktout);
6435 * Buffer banner messages for later display at some convenient point.
6437 static void ssh2_msg_userauth_banner(Ssh ssh, struct Packet *pktin)
6439 /* Arbitrary limit to prevent unbounded inflation of buffer */
6440 if (bufchain_size(&ssh->banner) <= 131072) {
6441 char *banner = NULL;
6443 ssh_pkt_getstring(pktin, &banner, &size);
6445 bufchain_add(&ssh->banner, banner, size);
6449 /* Helper function to deal with sending tty modes for "pty-req" */
6450 static void ssh2_send_ttymode(void *data, char *mode, char *val)
6452 struct Packet *pktout = (struct Packet *)data;
6454 unsigned int arg = 0;
6455 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
6456 if (i == lenof(ssh_ttymodes)) return;
6457 switch (ssh_ttymodes[i].type) {
6459 arg = ssh_tty_parse_specchar(val);
6462 arg = ssh_tty_parse_boolean(val);
6465 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
6466 ssh2_pkt_adduint32(pktout, arg);
6470 * Handle the SSH-2 userauth and connection layers.
6472 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
6473 struct Packet *pktin)
6475 struct do_ssh2_authconn_state {
6478 AUTH_TYPE_PUBLICKEY,
6479 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
6480 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
6482 AUTH_TYPE_KEYBOARD_INTERACTIVE,
6483 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
6485 int done_service_req;
6486 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
6487 int tried_pubkey_config, tried_agent;
6488 int kbd_inter_refused;
6490 prompts_t *cur_prompt;
6494 void *publickey_blob;
6495 int publickey_bloblen;
6496 int publickey_encrypted;
6497 char *publickey_algorithm;
6498 char *publickey_comment;
6499 unsigned char request[5], *response, *p;
6503 char *pkblob, *alg, *commentp;
6504 int pklen, alglen, commentlen;
6505 int siglen, retlen, len;
6506 char *q, *agentreq, *ret;
6508 int num_env, env_left, env_ok;
6509 struct Packet *pktout;
6511 crState(do_ssh2_authconn_state);
6513 crBegin(ssh->do_ssh2_authconn_crstate);
6515 s->done_service_req = FALSE;
6516 s->we_are_in = FALSE;
6517 if (!ssh->cfg.ssh_no_userauth) {
6519 * Request userauth protocol, and await a response to it.
6521 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
6522 ssh2_pkt_addstring(s->pktout, "ssh-userauth");
6523 ssh2_pkt_send(ssh, s->pktout);
6524 crWaitUntilV(pktin);
6525 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT)
6526 s->done_service_req = TRUE;
6528 if (!s->done_service_req) {
6530 * Request connection protocol directly, without authentication.
6532 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
6533 ssh2_pkt_addstring(s->pktout, "ssh-connection");
6534 ssh2_pkt_send(ssh, s->pktout);
6535 crWaitUntilV(pktin);
6536 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT) {
6537 s->we_are_in = TRUE; /* no auth required */
6539 bombout(("Server refused service request"));
6545 * Misc one-time setup for authentication.
6547 s->publickey_blob = NULL;
6548 if (!s->we_are_in) {
6551 * Load the public half of any configured public key file
6554 if (!filename_is_null(ssh->cfg.keyfile)) {
6556 logeventf(ssh, "Reading private key file \"%.150s\"",
6557 filename_to_str(&ssh->cfg.keyfile));
6558 keytype = key_type(&ssh->cfg.keyfile);
6559 if (keytype == SSH_KEYTYPE_SSH2) {
6562 ssh2_userkey_loadpub(&ssh->cfg.keyfile,
6563 &s->publickey_algorithm,
6564 &s->publickey_bloblen,
6565 &s->publickey_comment, &error);
6566 if (s->publickey_blob) {
6567 s->publickey_encrypted =
6568 ssh2_userkey_encrypted(&ssh->cfg.keyfile, NULL);
6571 logeventf(ssh, "Unable to load private key (%s)",
6573 msgbuf = dupprintf("Unable to load private key file "
6574 "\"%.150s\" (%s)\r\n",
6575 filename_to_str(&ssh->cfg.keyfile),
6577 c_write_str(ssh, msgbuf);
6582 logeventf(ssh, "Unable to use this key file (%s)",
6583 key_type_to_str(keytype));
6584 msgbuf = dupprintf("Unable to use key file \"%.150s\""
6586 filename_to_str(&ssh->cfg.keyfile),
6587 key_type_to_str(keytype));
6588 c_write_str(ssh, msgbuf);
6590 s->publickey_blob = NULL;
6597 * We repeat this whole loop, including the username prompt,
6598 * until we manage a successful authentication. If the user
6599 * types the wrong _password_, they can be sent back to the
6600 * beginning to try another username, if this is configured on.
6601 * (If they specify a username in the config, they are never
6602 * asked, even if they do give a wrong password.)
6604 * I think this best serves the needs of
6606 * - the people who have no configuration, no keys, and just
6607 * want to try repeated (username,password) pairs until they
6608 * type both correctly
6610 * - people who have keys and configuration but occasionally
6611 * need to fall back to passwords
6613 * - people with a key held in Pageant, who might not have
6614 * logged in to a particular machine before; so they want to
6615 * type a username, and then _either_ their key will be
6616 * accepted, _or_ they will type a password. If they mistype
6617 * the username they will want to be able to get back and
6620 s->username[0] = '\0';
6621 s->got_username = FALSE;
6622 bufchain_init(&ssh->banner);
6623 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] =
6624 ssh2_msg_userauth_banner;
6625 while (!s->we_are_in) {
6629 if (s->got_username && !ssh->cfg.change_username) {
6631 * We got a username last time round this loop, and
6632 * with change_username turned off we don't try to get
6635 } else if (!*ssh->cfg.username) {
6636 int ret; /* need not be kept over crReturn */
6637 s->cur_prompt = new_prompts(ssh->frontend);
6638 s->cur_prompt->to_server = TRUE;
6639 s->cur_prompt->name = dupstr("SSH login name");
6640 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE,
6641 lenof(s->username));
6642 ret = get_userpass_input(s->cur_prompt, NULL, 0);
6645 crWaitUntilV(!pktin);
6646 ret = get_userpass_input(s->cur_prompt, in, inlen);
6651 * get_userpass_input() failed to get a username.
6654 free_prompts(s->cur_prompt);
6655 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
6658 memcpy(s->username, s->cur_prompt->prompts[0]->result,
6659 lenof(s->username));
6660 free_prompts(s->cur_prompt);
6663 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
6664 s->username[sizeof(s->username)-1] = '\0';
6665 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
6666 stuff = dupprintf("Using username \"%s\".\r\n", s->username);
6667 c_write_str(ssh, stuff);
6671 s->got_username = TRUE;
6674 * Send an authentication request using method "none": (a)
6675 * just in case it succeeds, and (b) so that we know what
6676 * authentication methods we can usefully try next.
6678 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6680 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6681 ssh2_pkt_addstring(s->pktout, s->username);
6682 ssh2_pkt_addstring(s->pktout, "ssh-connection");/* service requested */
6683 ssh2_pkt_addstring(s->pktout, "none"); /* method */
6684 ssh2_pkt_send(ssh, s->pktout);
6685 s->type = AUTH_TYPE_NONE;
6687 s->we_are_in = FALSE;
6689 s->tried_pubkey_config = FALSE;
6690 s->tried_agent = FALSE;
6691 s->kbd_inter_refused = FALSE;
6695 * Wait for the result of the last authentication request.
6698 crWaitUntilV(pktin);
6700 * Now is a convenient point to spew any banner material
6701 * that we've accumulated. (This should ensure that when
6702 * we exit the auth loop, we haven't any left to deal
6706 int size = bufchain_size(&ssh->banner);
6708 * Don't show the banner if we're operating in
6709 * non-verbose non-interactive mode. (It's probably
6710 * a script, which means nobody will read the
6711 * banner _anyway_, and moreover the printing of
6712 * the banner will screw up processing on the
6713 * output of (say) plink.)
6715 if (size && (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE))) {
6716 char *banner = snewn(size, char);
6717 bufchain_fetch(&ssh->banner, banner, size);
6718 c_write_untrusted(ssh, banner, size);
6721 bufchain_clear(&ssh->banner);
6723 if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) {
6724 logevent("Access granted");
6725 s->we_are_in = TRUE;
6729 if (pktin->type == SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ) {
6730 /* FIXME: perhaps we should support this? */
6731 bombout(("PASSWD_CHANGEREQ not yet supported"));
6733 } else if (pktin->type != SSH2_MSG_USERAUTH_FAILURE) {
6734 bombout(("Strange packet received during authentication: type %d",
6742 * OK, we're now sitting on a USERAUTH_FAILURE message, so
6743 * we can look at the string in it and know what we can
6744 * helpfully try next.
6746 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) {
6749 ssh_pkt_getstring(pktin, &methods, &methlen);
6750 if (!ssh2_pkt_getbool(pktin)) {
6752 * We have received an unequivocal Access
6753 * Denied. This can translate to a variety of
6756 * - if we'd just tried "none" authentication,
6757 * it's not worth printing anything at all
6759 * - if we'd just tried a public key _offer_,
6760 * the message should be "Server refused our
6761 * key" (or no message at all if the key
6762 * came from Pageant)
6764 * - if we'd just tried anything else, the
6765 * message really should be "Access denied".
6767 * Additionally, if we'd just tried password
6768 * authentication, we should break out of this
6769 * whole loop so as to go back to the username
6770 * prompt (iff we're configured to allow
6771 * username change attempts).
6773 if (s->type == AUTH_TYPE_NONE) {
6775 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
6776 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
6777 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
6778 c_write_str(ssh, "Server refused our key\r\n");
6779 logevent("Server refused public key");
6780 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
6781 /* server declined keyboard-interactive; ignore */
6783 c_write_str(ssh, "Access denied\r\n");
6784 logevent("Access denied");
6785 if (s->type == AUTH_TYPE_PASSWORD &&
6786 ssh->cfg.change_username) {
6787 /* XXX perhaps we should allow
6788 * keyboard-interactive to do this too? */
6789 s->we_are_in = FALSE;
6794 c_write_str(ssh, "Further authentication required\r\n");
6795 logevent("Further authentication required");
6799 in_commasep_string("publickey", methods, methlen);
6801 in_commasep_string("password", methods, methlen);
6802 s->can_keyb_inter = ssh->cfg.try_ki_auth &&
6803 in_commasep_string("keyboard-interactive", methods, methlen);
6806 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6808 if (s->can_pubkey && agent_exists() && !s->tried_agent) {
6811 * Attempt public-key authentication using Pageant.
6816 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6817 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
6819 s->tried_agent = TRUE;
6821 logevent("Pageant is running. Requesting keys.");
6823 /* Request the keys held by the agent. */
6824 PUT_32BIT(s->request, 1);
6825 s->request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
6826 if (!agent_query(s->request, 5, &r, &s->responselen,
6827 ssh_agent_callback, ssh)) {
6831 bombout(("Unexpected data from server while"
6832 " waiting for agent response"));
6835 } while (pktin || inlen > 0);
6836 r = ssh->agent_response;
6837 s->responselen = ssh->agent_response_len;
6839 s->response = (unsigned char *) r;
6840 if (s->response && s->responselen >= 5 &&
6841 s->response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
6842 s->p = s->response + 5;
6843 s->nkeys = GET_32BIT(s->p);
6845 logeventf(ssh, "Pageant has %d SSH-2 keys", s->nkeys);
6846 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
6849 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
6850 s->pklen = GET_32BIT(s->p);
6852 if (s->publickey_blob &&
6853 s->pklen == s->publickey_bloblen &&
6854 !memcmp(s->p, s->publickey_blob,
6855 s->publickey_bloblen)) {
6856 logevent("This key matches configured key file");
6857 s->tried_pubkey_config = 1;
6859 s->pkblob = (char *)s->p;
6861 s->alglen = GET_32BIT(s->pkblob);
6862 s->alg = s->pkblob + 4;
6863 s->commentlen = GET_32BIT(s->p);
6865 s->commentp = (char *)s->p;
6866 s->p += s->commentlen;
6867 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6868 ssh2_pkt_addstring(s->pktout, s->username);
6869 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6870 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6871 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
6872 ssh2_pkt_addstring_start(s->pktout);
6873 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
6874 ssh2_pkt_addstring_start(s->pktout);
6875 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
6876 ssh2_pkt_send(ssh, s->pktout);
6878 crWaitUntilV(pktin);
6879 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
6880 logevent("Key refused");
6884 if (flags & FLAG_VERBOSE) {
6885 c_write_str(ssh, "Authenticating with "
6887 c_write(ssh, s->commentp, s->commentlen);
6888 c_write_str(ssh, "\" from agent\r\n");
6892 * Server is willing to accept the key.
6893 * Construct a SIGN_REQUEST.
6895 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6896 ssh2_pkt_addstring(s->pktout, s->username);
6897 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6898 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6899 ssh2_pkt_addbool(s->pktout, TRUE);
6900 ssh2_pkt_addstring_start(s->pktout);
6901 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
6902 ssh2_pkt_addstring_start(s->pktout);
6903 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
6905 s->siglen = s->pktout->length - 5 + 4 +
6906 ssh->v2_session_id_len;
6907 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
6909 s->len = 1; /* message type */
6910 s->len += 4 + s->pklen; /* key blob */
6911 s->len += 4 + s->siglen; /* data to sign */
6912 s->len += 4; /* flags */
6913 s->agentreq = snewn(4 + s->len, char);
6914 PUT_32BIT(s->agentreq, s->len);
6915 s->q = s->agentreq + 4;
6916 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
6917 PUT_32BIT(s->q, s->pklen);
6919 memcpy(s->q, s->pkblob, s->pklen);
6921 PUT_32BIT(s->q, s->siglen);
6923 /* Now the data to be signed... */
6924 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
6925 PUT_32BIT(s->q, ssh->v2_session_id_len);
6928 memcpy(s->q, ssh->v2_session_id,
6929 ssh->v2_session_id_len);
6930 s->q += ssh->v2_session_id_len;
6931 memcpy(s->q, s->pktout->data + 5,
6932 s->pktout->length - 5);
6933 s->q += s->pktout->length - 5;
6934 /* And finally the (zero) flags word. */
6936 if (!agent_query(s->agentreq, s->len + 4,
6938 ssh_agent_callback, ssh)) {
6942 bombout(("Unexpected data from server"
6943 " while waiting for agent"
6947 } while (pktin || inlen > 0);
6948 vret = ssh->agent_response;
6949 s->retlen = ssh->agent_response_len;
6954 if (s->ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
6955 logevent("Sending Pageant's response");
6956 ssh2_add_sigblob(ssh, s->pktout,
6957 s->pkblob, s->pklen,
6959 GET_32BIT(s->ret + 5));
6960 ssh2_pkt_send(ssh, s->pktout);
6965 ("Pageant failed to answer challenge");
6975 } else if (s->can_pubkey && s->publickey_blob &&
6976 !s->tried_pubkey_config) {
6978 struct ssh2_userkey *key; /* not live over crReturn */
6979 char *passphrase; /* not live over crReturn */
6981 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6982 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
6984 s->tried_pubkey_config = TRUE;
6987 * Try the public key supplied in the configuration.
6989 * First, offer the public blob to see if the server is
6990 * willing to accept it.
6992 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6993 ssh2_pkt_addstring(s->pktout, s->username);
6994 ssh2_pkt_addstring(s->pktout, "ssh-connection");
6995 /* service requested */
6996 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6997 ssh2_pkt_addbool(s->pktout, FALSE);
6998 /* no signature included */
6999 ssh2_pkt_addstring(s->pktout, s->publickey_algorithm);
7000 ssh2_pkt_addstring_start(s->pktout);
7001 ssh2_pkt_addstring_data(s->pktout,
7002 (char *)s->publickey_blob,
7003 s->publickey_bloblen);
7004 ssh2_pkt_send(ssh, s->pktout);
7005 logevent("Offered public key");
7007 crWaitUntilV(pktin);
7008 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
7009 /* Key refused. Give up. */
7010 s->gotit = TRUE; /* reconsider message next loop */
7011 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
7012 continue; /* process this new message */
7014 logevent("Offer of public key accepted");
7017 * Actually attempt a serious authentication using
7020 if (flags & FLAG_VERBOSE) {
7021 c_write_str(ssh, "Authenticating with public key \"");
7022 c_write_str(ssh, s->publickey_comment);
7023 c_write_str(ssh, "\"\r\n");
7027 const char *error; /* not live over crReturn */
7028 if (s->publickey_encrypted) {
7030 * Get a passphrase from the user.
7032 int ret; /* need not be kept over crReturn */
7033 s->cur_prompt = new_prompts(ssh->frontend);
7034 s->cur_prompt->to_server = FALSE;
7035 s->cur_prompt->name = dupstr("SSH key passphrase");
7036 add_prompt(s->cur_prompt,
7037 dupprintf("Passphrase for key \"%.100s\": ",
7038 s->publickey_comment),
7039 FALSE, SSH_MAX_PASSWORD_LEN);
7040 ret = get_userpass_input(s->cur_prompt, NULL, 0);
7043 crWaitUntilV(!pktin);
7044 ret = get_userpass_input(s->cur_prompt,
7049 /* Failed to get a passphrase. Terminate. */
7050 free_prompts(s->cur_prompt);
7051 ssh_disconnect(ssh, NULL,
7052 "Unable to authenticate",
7053 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
7058 dupstr(s->cur_prompt->prompts[0]->result);
7059 free_prompts(s->cur_prompt);
7061 passphrase = NULL; /* no passphrase needed */
7065 * Try decrypting the key.
7067 key = ssh2_load_userkey(&ssh->cfg.keyfile, passphrase,
7070 /* burn the evidence */
7071 memset(passphrase, 0, strlen(passphrase));
7074 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
7076 (key == SSH2_WRONG_PASSPHRASE)) {
7077 c_write_str(ssh, "Wrong passphrase\r\n");
7079 /* and loop again */
7081 c_write_str(ssh, "Unable to load private key (");
7082 c_write_str(ssh, error);
7083 c_write_str(ssh, ")\r\n");
7085 break; /* try something else */
7091 unsigned char *pkblob, *sigblob, *sigdata;
7092 int pkblob_len, sigblob_len, sigdata_len;
7096 * We have loaded the private key and the server
7097 * has announced that it's willing to accept it.
7098 * Hallelujah. Generate a signature and send it.
7100 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
7101 ssh2_pkt_addstring(s->pktout, s->username);
7102 ssh2_pkt_addstring(s->pktout, "ssh-connection");
7103 /* service requested */
7104 ssh2_pkt_addstring(s->pktout, "publickey");
7106 ssh2_pkt_addbool(s->pktout, TRUE);
7107 /* signature follows */
7108 ssh2_pkt_addstring(s->pktout, key->alg->name);
7109 pkblob = key->alg->public_blob(key->data,
7111 ssh2_pkt_addstring_start(s->pktout);
7112 ssh2_pkt_addstring_data(s->pktout, (char *)pkblob,
7116 * The data to be signed is:
7120 * followed by everything so far placed in the
7123 sigdata_len = s->pktout->length - 5 + 4 +
7124 ssh->v2_session_id_len;
7125 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
7127 sigdata = snewn(sigdata_len, unsigned char);
7129 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
7130 PUT_32BIT(sigdata+p, ssh->v2_session_id_len);
7133 memcpy(sigdata+p, ssh->v2_session_id,
7134 ssh->v2_session_id_len);
7135 p += ssh->v2_session_id_len;
7136 memcpy(sigdata+p, s->pktout->data + 5,
7137 s->pktout->length - 5);
7138 p += s->pktout->length - 5;
7139 assert(p == sigdata_len);
7140 sigblob = key->alg->sign(key->data, (char *)sigdata,
7141 sigdata_len, &sigblob_len);
7142 ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len,
7143 sigblob, sigblob_len);
7148 ssh2_pkt_send(ssh, s->pktout);
7149 s->type = AUTH_TYPE_PUBLICKEY;
7150 key->alg->freekey(key->data);
7153 } else if (s->can_keyb_inter && !s->kbd_inter_refused) {
7156 * Keyboard-interactive authentication.
7158 char *name, *inst, *lang;
7159 int name_len, inst_len, lang_len;
7162 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
7164 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
7165 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
7167 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
7168 ssh2_pkt_addstring(s->pktout, s->username);
7169 ssh2_pkt_addstring(s->pktout, "ssh-connection");
7170 /* service requested */
7171 ssh2_pkt_addstring(s->pktout, "keyboard-interactive");
7173 ssh2_pkt_addstring(s->pktout, ""); /* lang */
7174 ssh2_pkt_addstring(s->pktout, ""); /* submethods */
7175 ssh2_pkt_send(ssh, s->pktout);
7177 crWaitUntilV(pktin);
7178 if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
7179 /* Server is not willing to do keyboard-interactive
7180 * at all. Give up on it entirely. */
7182 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE)
7183 logevent("Keyboard-interactive authentication refused");
7184 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
7185 s->kbd_inter_refused = TRUE; /* don't try it again */
7190 * We've got a fresh USERAUTH_INFO_REQUEST.
7191 * Get the preamble and start building a prompt.
7193 ssh_pkt_getstring(pktin, &name, &name_len);
7194 ssh_pkt_getstring(pktin, &inst, &inst_len);
7195 ssh_pkt_getstring(pktin, &lang, &lang_len);
7196 s->cur_prompt = new_prompts(ssh->frontend);
7197 s->cur_prompt->to_server = TRUE;
7199 /* FIXME: better prefix to distinguish from
7201 s->cur_prompt->name = dupprintf("SSH server: %.*s",
7203 s->cur_prompt->name_reqd = TRUE;
7205 s->cur_prompt->name = dupstr("SSH server authentication");
7206 s->cur_prompt->name_reqd = FALSE;
7208 s->cur_prompt->instruction =
7209 dupprintf("Using keyboard-interactive authentication.%s%.*s",
7210 inst_len ? "\n" : "", inst_len, inst);
7211 s->cur_prompt->instr_reqd = TRUE;
7214 * Get the prompts from the packet.
7216 s->num_prompts = ssh_pkt_getuint32(pktin);
7217 for (i = 0; i < s->num_prompts; i++) {
7221 static char noprompt[] =
7222 "<server failed to send prompt>: ";
7224 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
7225 echo = ssh2_pkt_getbool(pktin);
7228 prompt_len = lenof(noprompt)-1;
7230 add_prompt(s->cur_prompt,
7231 dupprintf("%.*s", prompt_len, prompt),
7232 echo, SSH_MAX_PASSWORD_LEN);
7236 * Get the user's responses.
7238 if (s->num_prompts) {
7239 int ret; /* not live over crReturn */
7240 ret = get_userpass_input(s->cur_prompt, NULL, 0);
7243 crWaitUntilV(!pktin);
7244 ret = get_userpass_input(s->cur_prompt, in, inlen);
7249 * Failed to get responses. Terminate.
7251 free_prompts(s->cur_prompt);
7252 ssh_disconnect(ssh, NULL, "Unable to authenticate",
7253 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
7260 * Send the responses to the server.
7262 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
7263 s->pktout->forcepad = 256;
7264 ssh2_pkt_adduint32(s->pktout, s->num_prompts);
7265 for (i=0; i < s->num_prompts; i++) {
7266 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
7267 ssh2_pkt_addstring(s->pktout,
7268 s->cur_prompt->prompts[i]->result);
7269 end_log_omission(ssh, s->pktout);
7271 ssh2_pkt_send(ssh, s->pktout);
7272 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
7274 } else if (s->can_passwd) {
7277 * Plain old password authentication.
7279 int ret; /* not live over crReturn */
7281 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
7282 ssh->pkt_ctx |= SSH2_PKTCTX_PASSWORD;
7284 s->cur_prompt = new_prompts(ssh->frontend);
7285 s->cur_prompt->to_server = TRUE;
7286 s->cur_prompt->name = dupstr("SSH password");
7287 add_prompt(s->cur_prompt, dupprintf("%.90s@%.90s's password: ",
7290 FALSE, SSH_MAX_PASSWORD_LEN);
7292 ret = get_userpass_input(s->cur_prompt, NULL, 0);
7295 crWaitUntilV(!pktin);
7296 ret = get_userpass_input(s->cur_prompt, in, inlen);
7301 * Failed to get responses. Terminate.
7303 free_prompts(s->cur_prompt);
7304 ssh_disconnect(ssh, NULL, "Unable to authenticate",
7305 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
7311 * Send the password packet.
7313 * We pad out the password packet to 256 bytes to make
7314 * it harder for an attacker to find the length of the
7317 * Anyone using a password longer than 256 bytes
7318 * probably doesn't have much to worry about from
7319 * people who find out how long their password is!
7321 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
7322 s->pktout->forcepad = 256;
7323 ssh2_pkt_addstring(s->pktout, s->username);
7324 ssh2_pkt_addstring(s->pktout, "ssh-connection");
7325 /* service requested */
7326 ssh2_pkt_addstring(s->pktout, "password");
7327 ssh2_pkt_addbool(s->pktout, FALSE);
7328 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
7329 ssh2_pkt_addstring(s->pktout,
7330 s->cur_prompt->prompts[0]->result);
7331 free_prompts(s->cur_prompt);
7332 end_log_omission(ssh, s->pktout);
7333 ssh2_pkt_send(ssh, s->pktout);
7334 logevent("Sent password");
7335 s->type = AUTH_TYPE_PASSWORD;
7339 ssh_disconnect(ssh, NULL,
7340 "No supported authentication methods available",
7341 SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE,
7349 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
7351 /* Clear up various bits and pieces from authentication. */
7352 if (s->publickey_blob) {
7353 sfree(s->publickey_blob);
7354 sfree(s->publickey_comment);
7358 * Now the connection protocol has started, one way or another.
7361 ssh->channels = newtree234(ssh_channelcmp);
7364 * Set up handlers for some connection protocol messages, so we
7365 * don't have to handle them repeatedly in this coroutine.
7367 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] =
7368 ssh2_msg_channel_window_adjust;
7369 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] =
7370 ssh2_msg_global_request;
7373 * Create the main session channel.
7375 if (!ssh->cfg.ssh_no_shell) {
7376 ssh->mainchan = snew(struct ssh_channel);
7377 ssh->mainchan->ssh = ssh;
7378 ssh->mainchan->localid = alloc_channel_id(ssh);
7379 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
7380 ssh2_pkt_addstring(s->pktout, "session");
7381 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->localid);
7382 ssh->mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
7383 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->v.v2.locwindow);/* our window size */
7384 ssh2_pkt_adduint32(s->pktout, OUR_V2_MAXPKT); /* our max pkt size */
7385 ssh2_pkt_send(ssh, s->pktout);
7386 crWaitUntilV(pktin);
7387 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
7388 bombout(("Server refused to open a session"));
7390 /* FIXME: error data comes back in FAILURE packet */
7392 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
7393 bombout(("Server's channel confirmation cited wrong channel"));
7396 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
7397 ssh->mainchan->halfopen = FALSE;
7398 ssh->mainchan->type = CHAN_MAINSESSION;
7399 ssh->mainchan->closes = 0;
7400 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
7401 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
7402 bufchain_init(&ssh->mainchan->v.v2.outbuffer);
7403 add234(ssh->channels, ssh->mainchan);
7404 update_specials_menu(ssh->frontend);
7405 logevent("Opened channel for session");
7407 ssh->mainchan = NULL;
7410 * Now we have a channel, make dispatch table entries for
7411 * general channel-based messages.
7413 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] =
7414 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] =
7415 ssh2_msg_channel_data;
7416 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_channel_eof;
7417 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_channel_close;
7418 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] =
7419 ssh2_msg_channel_open_confirmation;
7420 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] =
7421 ssh2_msg_channel_open_failure;
7422 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] =
7423 ssh2_msg_channel_request;
7424 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] =
7425 ssh2_msg_channel_open;
7428 * Potentially enable X11 forwarding.
7430 if (ssh->mainchan && ssh->cfg.x11_forward) {
7431 char proto[20], data[64];
7432 logevent("Requesting X11 forwarding");
7433 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
7434 data, sizeof(data), ssh->cfg.x11_auth);
7435 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
7436 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7437 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
7438 ssh2_pkt_addstring(s->pktout, "x11-req");
7439 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7440 ssh2_pkt_addbool(s->pktout, 0); /* many connections */
7441 ssh2_pkt_addstring(s->pktout, proto);
7443 * Note that while we blank the X authentication data here, we don't
7444 * take any special action to blank the start of an X11 channel,
7445 * so using MIT-MAGIC-COOKIE-1 and actually opening an X connection
7446 * without having session blanking enabled is likely to leak your
7447 * cookie into the log.
7449 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
7450 ssh2_pkt_addstring(s->pktout, data);
7451 end_log_omission(ssh, s->pktout);
7452 ssh2_pkt_adduint32(s->pktout, x11_get_screen_number(ssh->cfg.x11_display));
7453 ssh2_pkt_send(ssh, s->pktout);
7455 crWaitUntilV(pktin);
7457 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7458 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
7459 bombout(("Unexpected response to X11 forwarding request:"
7460 " packet type %d", pktin->type));
7463 logevent("X11 forwarding refused");
7465 logevent("X11 forwarding enabled");
7466 ssh->X11_fwd_enabled = TRUE;
7471 * Enable port forwardings.
7473 ssh_setup_portfwd(ssh, &ssh->cfg);
7476 * Potentially enable agent forwarding.
7478 if (ssh->mainchan && ssh->cfg.agentfwd && agent_exists()) {
7479 logevent("Requesting OpenSSH-style agent forwarding");
7480 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7481 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
7482 ssh2_pkt_addstring(s->pktout, "auth-agent-req@openssh.com");
7483 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7484 ssh2_pkt_send(ssh, s->pktout);
7486 crWaitUntilV(pktin);
7488 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7489 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
7490 bombout(("Unexpected response to agent forwarding request:"
7491 " packet type %d", pktin->type));
7494 logevent("Agent forwarding refused");
7496 logevent("Agent forwarding enabled");
7497 ssh->agentfwd_enabled = TRUE;
7502 * Now allocate a pty for the session.
7504 if (ssh->mainchan && !ssh->cfg.nopty) {
7505 /* Unpick the terminal-speed string. */
7506 /* XXX perhaps we should allow no speeds to be sent. */
7507 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
7508 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
7509 /* Build the pty request. */
7510 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7511 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
7512 ssh2_pkt_addstring(s->pktout, "pty-req");
7513 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7514 ssh2_pkt_addstring(s->pktout, ssh->cfg.termtype);
7515 ssh2_pkt_adduint32(s->pktout, ssh->term_width);
7516 ssh2_pkt_adduint32(s->pktout, ssh->term_height);
7517 ssh2_pkt_adduint32(s->pktout, 0); /* pixel width */
7518 ssh2_pkt_adduint32(s->pktout, 0); /* pixel height */
7519 ssh2_pkt_addstring_start(s->pktout);
7520 parse_ttymodes(ssh, ssh->cfg.ttymodes,
7521 ssh2_send_ttymode, (void *)s->pktout);
7522 ssh2_pkt_addbyte(s->pktout, SSH2_TTY_OP_ISPEED);
7523 ssh2_pkt_adduint32(s->pktout, ssh->ispeed);
7524 ssh2_pkt_addbyte(s->pktout, SSH2_TTY_OP_OSPEED);
7525 ssh2_pkt_adduint32(s->pktout, ssh->ospeed);
7526 ssh2_pkt_addstring_data(s->pktout, "\0", 1); /* TTY_OP_END */
7527 ssh2_pkt_send(ssh, s->pktout);
7528 ssh->state = SSH_STATE_INTERMED;
7530 crWaitUntilV(pktin);
7532 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7533 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
7534 bombout(("Unexpected response to pty request:"
7535 " packet type %d", pktin->type));
7538 c_write_str(ssh, "Server refused to allocate pty\r\n");
7539 ssh->editing = ssh->echoing = 1;
7541 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
7542 ssh->ospeed, ssh->ispeed);
7545 ssh->editing = ssh->echoing = 1;
7549 * Send environment variables.
7551 * Simplest thing here is to send all the requests at once, and
7552 * then wait for a whole bunch of successes or failures.
7554 if (ssh->mainchan && *ssh->cfg.environmt) {
7555 char *e = ssh->cfg.environmt;
7556 char *var, *varend, *val;
7562 while (*e && *e != '\t') e++;
7564 if (*e == '\t') e++;
7569 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7570 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
7571 ssh2_pkt_addstring(s->pktout, "env");
7572 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7573 ssh2_pkt_addstring_start(s->pktout);
7574 ssh2_pkt_addstring_data(s->pktout, var, varend-var);
7575 ssh2_pkt_addstring(s->pktout, val);
7576 ssh2_pkt_send(ssh, s->pktout);
7581 logeventf(ssh, "Sent %d environment variables", s->num_env);
7584 s->env_left = s->num_env;
7586 while (s->env_left > 0) {
7587 crWaitUntilV(pktin);
7589 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7590 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
7591 bombout(("Unexpected response to environment request:"
7592 " packet type %d", pktin->type));
7602 if (s->env_ok == s->num_env) {
7603 logevent("All environment variables successfully set");
7604 } else if (s->env_ok == 0) {
7605 logevent("All environment variables refused");
7606 c_write_str(ssh, "Server refused to set environment variables\r\n");
7608 logeventf(ssh, "%d environment variables refused",
7609 s->num_env - s->env_ok);
7610 c_write_str(ssh, "Server refused to set all environment variables\r\n");
7615 * Start a shell or a remote command. We may have to attempt
7616 * this twice if the config data has provided a second choice
7619 if (ssh->mainchan) while (1) {
7623 if (ssh->fallback_cmd) {
7624 subsys = ssh->cfg.ssh_subsys2;
7625 cmd = ssh->cfg.remote_cmd_ptr2;
7627 subsys = ssh->cfg.ssh_subsys;
7628 cmd = ssh->cfg.remote_cmd_ptr;
7629 if (!cmd) cmd = ssh->cfg.remote_cmd;
7632 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7633 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
7635 ssh2_pkt_addstring(s->pktout, "subsystem");
7636 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7637 ssh2_pkt_addstring(s->pktout, cmd);
7639 ssh2_pkt_addstring(s->pktout, "exec");
7640 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7641 ssh2_pkt_addstring(s->pktout, cmd);
7643 ssh2_pkt_addstring(s->pktout, "shell");
7644 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7646 ssh2_pkt_send(ssh, s->pktout);
7648 crWaitUntilV(pktin);
7650 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7651 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
7652 bombout(("Unexpected response to shell/command request:"
7653 " packet type %d", pktin->type));
7657 * We failed to start the command. If this is the
7658 * fallback command, we really are finished; if it's
7659 * not, and if the fallback command exists, try falling
7660 * back to it before complaining.
7662 if (!ssh->fallback_cmd && ssh->cfg.remote_cmd_ptr2 != NULL) {
7663 logevent("Primary command failed; attempting fallback");
7664 ssh->fallback_cmd = TRUE;
7667 bombout(("Server refused to start a shell/command"));
7670 logevent("Started a shell/command");
7675 ssh->state = SSH_STATE_SESSION;
7676 if (ssh->size_needed)
7677 ssh_size(ssh, ssh->term_width, ssh->term_height);
7678 if (ssh->eof_needed)
7679 ssh_special(ssh, TS_EOF);
7685 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
7690 s->try_send = FALSE;
7694 * _All_ the connection-layer packets we expect to
7695 * receive are now handled by the dispatch table.
7696 * Anything that reaches here must be bogus.
7699 bombout(("Strange packet received: type %d", pktin->type));
7701 } else if (ssh->mainchan) {
7703 * We have spare data. Add it to the channel buffer.
7705 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
7710 struct ssh_channel *c;
7712 * Try to send data on all channels if we can.
7714 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++)
7715 ssh2_try_send_and_unthrottle(c);
7723 * Handlers for SSH-2 messages that might arrive at any moment.
7725 static void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin)
7727 /* log reason code in disconnect message */
7729 int nowlen, reason, msglen;
7731 reason = ssh_pkt_getuint32(pktin);
7732 ssh_pkt_getstring(pktin, &msg, &msglen);
7734 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
7735 buf = dupprintf("Received disconnect message (%s)",
7736 ssh2_disconnect_reasons[reason]);
7738 buf = dupprintf("Received disconnect message (unknown"
7739 " type %d)", reason);
7743 buf = dupprintf("Disconnection message text: %n%.*s",
7744 &nowlen, msglen, msg);
7746 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
7748 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
7749 ssh2_disconnect_reasons[reason] : "unknown",
7754 static void ssh2_msg_debug(Ssh ssh, struct Packet *pktin)
7756 /* log the debug message */
7761 /* XXX maybe we should actually take notice of this */
7762 always_display = ssh2_pkt_getbool(pktin);
7763 ssh_pkt_getstring(pktin, &msg, &msglen);
7765 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
7768 static void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin)
7770 struct Packet *pktout;
7771 pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
7772 ssh2_pkt_adduint32(pktout, pktin->sequence);
7774 * UNIMPLEMENTED messages MUST appear in the same order as the
7775 * messages they respond to. Hence, never queue them.
7777 ssh2_pkt_send_noqueue(ssh, pktout);
7781 * Handle the top-level SSH-2 protocol.
7783 static void ssh2_protocol_setup(Ssh ssh)
7788 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
7790 for (i = 0; i < 256; i++)
7791 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
7794 * Any message we actually understand, we set to NULL so that
7795 * the coroutines will get it.
7797 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = NULL;
7798 ssh->packet_dispatch[SSH2_MSG_SERVICE_REQUEST] = NULL;
7799 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = NULL;
7800 ssh->packet_dispatch[SSH2_MSG_KEXINIT] = NULL;
7801 ssh->packet_dispatch[SSH2_MSG_NEWKEYS] = NULL;
7802 ssh->packet_dispatch[SSH2_MSG_KEXDH_INIT] = NULL;
7803 ssh->packet_dispatch[SSH2_MSG_KEXDH_REPLY] = NULL;
7804 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = NULL; duplicate case value */
7805 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = NULL; duplicate case value */
7806 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_INIT] = NULL;
7807 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REPLY] = NULL;
7808 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = NULL;
7809 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = NULL;
7810 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = NULL;
7811 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
7812 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = NULL;
7813 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = NULL; duplicate case value */
7814 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = NULL; duplicate case value */
7815 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = NULL;
7816 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = NULL;
7817 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = NULL;
7818 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = NULL;
7819 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = NULL;
7820 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = NULL;
7821 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = NULL;
7822 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = NULL;
7823 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = NULL;
7824 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = NULL;
7825 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = NULL;
7826 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = NULL;
7827 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = NULL;
7828 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = NULL;
7829 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = NULL;
7832 * These special message types we install handlers for.
7834 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
7835 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with SSH-1 */
7836 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
7839 static void ssh2_timer(void *ctx, long now)
7843 if (ssh->state == SSH_STATE_CLOSED)
7846 if (!ssh->kex_in_progress && ssh->cfg.ssh_rekey_time != 0 &&
7847 now - ssh->next_rekey >= 0) {
7848 do_ssh2_transport(ssh, "timeout", -1, NULL);
7852 static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
7853 struct Packet *pktin)
7855 unsigned char *in = (unsigned char *)vin;
7856 if (ssh->state == SSH_STATE_CLOSED)
7860 ssh->incoming_data_size += pktin->encrypted_len;
7861 if (!ssh->kex_in_progress &&
7862 ssh->max_data_size != 0 &&
7863 ssh->incoming_data_size > ssh->max_data_size)
7864 do_ssh2_transport(ssh, "too much data received", -1, NULL);
7867 if (pktin && ssh->packet_dispatch[pktin->type]) {
7868 ssh->packet_dispatch[pktin->type](ssh, pktin);
7872 if (!ssh->protocol_initial_phase_done ||
7873 (pktin && pktin->type >= 20 && pktin->type < 50)) {
7874 if (do_ssh2_transport(ssh, in, inlen, pktin) &&
7875 !ssh->protocol_initial_phase_done) {
7876 ssh->protocol_initial_phase_done = TRUE;
7878 * Allow authconn to initialise itself.
7880 do_ssh2_authconn(ssh, NULL, 0, NULL);
7883 do_ssh2_authconn(ssh, in, inlen, pktin);
7888 * Called to set up the connection.
7890 * Returns an error message, or NULL on success.
7892 static const char *ssh_init(void *frontend_handle, void **backend_handle,
7894 char *host, int port, char **realhost, int nodelay,
7900 ssh = snew(struct ssh_tag);
7901 ssh->cfg = *cfg; /* STRUCTURE COPY */
7902 ssh->version = 0; /* when not ready yet */
7905 ssh->v1_cipher_ctx = NULL;
7906 ssh->crcda_ctx = NULL;
7907 ssh->cscipher = NULL;
7908 ssh->cs_cipher_ctx = NULL;
7909 ssh->sccipher = NULL;
7910 ssh->sc_cipher_ctx = NULL;
7912 ssh->cs_mac_ctx = NULL;
7914 ssh->sc_mac_ctx = NULL;
7916 ssh->cs_comp_ctx = NULL;
7918 ssh->sc_comp_ctx = NULL;
7920 ssh->kex_ctx = NULL;
7921 ssh->hostkey = NULL;
7923 ssh->close_expected = FALSE;
7924 ssh->clean_exit = FALSE;
7925 ssh->state = SSH_STATE_PREPACKET;
7926 ssh->size_needed = FALSE;
7927 ssh->eof_needed = FALSE;
7930 ssh->deferred_send_data = NULL;
7931 ssh->deferred_len = 0;
7932 ssh->deferred_size = 0;
7933 ssh->fallback_cmd = 0;
7935 ssh->x11auth = NULL;
7936 ssh->v1_compressing = FALSE;
7937 ssh->v2_outgoing_sequence = 0;
7938 ssh->ssh1_rdpkt_crstate = 0;
7939 ssh->ssh2_rdpkt_crstate = 0;
7940 ssh->do_ssh_init_crstate = 0;
7941 ssh->ssh_gotdata_crstate = 0;
7942 ssh->do_ssh1_connection_crstate = 0;
7943 ssh->do_ssh1_login_crstate = 0;
7944 ssh->do_ssh2_transport_crstate = 0;
7945 ssh->do_ssh2_authconn_crstate = 0;
7946 ssh->do_ssh_init_state = NULL;
7947 ssh->do_ssh1_login_state = NULL;
7948 ssh->do_ssh2_transport_state = NULL;
7949 ssh->do_ssh2_authconn_state = NULL;
7952 ssh->mainchan = NULL;
7953 ssh->throttled_all = 0;
7954 ssh->v1_stdout_throttling = 0;
7956 ssh->queuelen = ssh->queuesize = 0;
7957 ssh->queueing = FALSE;
7958 ssh->qhead = ssh->qtail = NULL;
7959 ssh->deferred_rekey_reason = NULL;
7960 bufchain_init(&ssh->queued_incoming_data);
7961 ssh->frozen = FALSE;
7963 *backend_handle = ssh;
7966 if (crypto_startup() == 0)
7967 return "Microsoft high encryption pack not installed!";
7970 ssh->frontend = frontend_handle;
7971 ssh->term_width = ssh->cfg.width;
7972 ssh->term_height = ssh->cfg.height;
7974 ssh->channels = NULL;
7975 ssh->rportfwds = NULL;
7976 ssh->portfwds = NULL;
7981 ssh->v1_throttle_count = 0;
7982 ssh->overall_bufsize = 0;
7983 ssh->fallback_cmd = 0;
7985 ssh->protocol = NULL;
7987 ssh->protocol_initial_phase_done = FALSE;
7991 ssh->incoming_data_size = ssh->outgoing_data_size =
7992 ssh->deferred_data_size = 0L;
7993 ssh->max_data_size = parse_blocksize(ssh->cfg.ssh_rekey_data);
7994 ssh->kex_in_progress = FALSE;
7996 p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
8005 static void ssh_free(void *handle)
8007 Ssh ssh = (Ssh) handle;
8008 struct ssh_channel *c;
8009 struct ssh_rportfwd *pf;
8011 if (ssh->v1_cipher_ctx)
8012 ssh->cipher->free_context(ssh->v1_cipher_ctx);
8013 if (ssh->cs_cipher_ctx)
8014 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
8015 if (ssh->sc_cipher_ctx)
8016 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
8017 if (ssh->cs_mac_ctx)
8018 ssh->csmac->free_context(ssh->cs_mac_ctx);
8019 if (ssh->sc_mac_ctx)
8020 ssh->scmac->free_context(ssh->sc_mac_ctx);
8021 if (ssh->cs_comp_ctx) {
8023 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
8025 zlib_compress_cleanup(ssh->cs_comp_ctx);
8027 if (ssh->sc_comp_ctx) {
8029 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
8031 zlib_decompress_cleanup(ssh->sc_comp_ctx);
8034 dh_cleanup(ssh->kex_ctx);
8035 sfree(ssh->savedhost);
8037 while (ssh->queuelen-- > 0)
8038 ssh_free_packet(ssh->queue[ssh->queuelen]);
8041 while (ssh->qhead) {
8042 struct queued_handler *qh = ssh->qhead;
8043 ssh->qhead = qh->next;
8046 ssh->qhead = ssh->qtail = NULL;
8048 if (ssh->channels) {
8049 while ((c = delpos234(ssh->channels, 0)) != NULL) {
8052 if (c->u.x11.s != NULL)
8053 x11_close(c->u.x11.s);
8056 if (c->u.pfd.s != NULL)
8057 pfd_close(c->u.pfd.s);
8062 freetree234(ssh->channels);
8063 ssh->channels = NULL;
8066 if (ssh->rportfwds) {
8067 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
8069 freetree234(ssh->rportfwds);
8070 ssh->rportfwds = NULL;
8072 sfree(ssh->deferred_send_data);
8074 x11_free_auth(ssh->x11auth);
8075 sfree(ssh->do_ssh_init_state);
8076 sfree(ssh->do_ssh1_login_state);
8077 sfree(ssh->do_ssh2_transport_state);
8078 sfree(ssh->do_ssh2_authconn_state);
8081 if (ssh->crcda_ctx) {
8082 crcda_free_context(ssh->crcda_ctx);
8083 ssh->crcda_ctx = NULL;
8086 ssh_do_close(ssh, TRUE);
8087 expire_timer_context(ssh);
8089 pinger_free(ssh->pinger);
8090 bufchain_clear(&ssh->queued_incoming_data);
8097 * Reconfigure the SSH backend.
8099 static void ssh_reconfig(void *handle, Config *cfg)
8101 Ssh ssh = (Ssh) handle;
8102 char *rekeying = NULL, rekey_mandatory = FALSE;
8103 unsigned long old_max_data_size;
8105 pinger_reconfig(ssh->pinger, &ssh->cfg, cfg);
8107 ssh_setup_portfwd(ssh, cfg);
8109 if (ssh->cfg.ssh_rekey_time != cfg->ssh_rekey_time &&
8110 cfg->ssh_rekey_time != 0) {
8111 long new_next = ssh->last_rekey + cfg->ssh_rekey_time*60*TICKSPERSEC;
8112 long now = GETTICKCOUNT();
8114 if (new_next - now < 0) {
8115 rekeying = "timeout shortened";
8117 ssh->next_rekey = schedule_timer(new_next - now, ssh2_timer, ssh);
8121 old_max_data_size = ssh->max_data_size;
8122 ssh->max_data_size = parse_blocksize(cfg->ssh_rekey_data);
8123 if (old_max_data_size != ssh->max_data_size &&
8124 ssh->max_data_size != 0) {
8125 if (ssh->outgoing_data_size > ssh->max_data_size ||
8126 ssh->incoming_data_size > ssh->max_data_size)
8127 rekeying = "data limit lowered";
8130 if (ssh->cfg.compression != cfg->compression) {
8131 rekeying = "compression setting changed";
8132 rekey_mandatory = TRUE;
8135 if (ssh->cfg.ssh2_des_cbc != cfg->ssh2_des_cbc ||
8136 memcmp(ssh->cfg.ssh_cipherlist, cfg->ssh_cipherlist,
8137 sizeof(ssh->cfg.ssh_cipherlist))) {
8138 rekeying = "cipher settings changed";
8139 rekey_mandatory = TRUE;
8142 ssh->cfg = *cfg; /* STRUCTURE COPY */
8145 if (!ssh->kex_in_progress) {
8146 do_ssh2_transport(ssh, rekeying, -1, NULL);
8147 } else if (rekey_mandatory) {
8148 ssh->deferred_rekey_reason = rekeying;
8154 * Called to send data down the SSH connection.
8156 static int ssh_send(void *handle, char *buf, int len)
8158 Ssh ssh = (Ssh) handle;
8160 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
8163 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
8165 return ssh_sendbuffer(ssh);
8169 * Called to query the current amount of buffered stdin data.
8171 static int ssh_sendbuffer(void *handle)
8173 Ssh ssh = (Ssh) handle;
8176 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
8180 * If the SSH socket itself has backed up, add the total backup
8181 * size on that to any individual buffer on the stdin channel.
8184 if (ssh->throttled_all)
8185 override_value = ssh->overall_bufsize;
8187 if (ssh->version == 1) {
8188 return override_value;
8189 } else if (ssh->version == 2) {
8190 if (!ssh->mainchan || ssh->mainchan->closes > 0)
8191 return override_value;
8193 return (override_value +
8194 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
8201 * Called to set the size of the window from SSH's POV.
8203 static void ssh_size(void *handle, int width, int height)
8205 Ssh ssh = (Ssh) handle;
8206 struct Packet *pktout;
8208 ssh->term_width = width;
8209 ssh->term_height = height;
8211 switch (ssh->state) {
8212 case SSH_STATE_BEFORE_SIZE:
8213 case SSH_STATE_PREPACKET:
8214 case SSH_STATE_CLOSED:
8215 break; /* do nothing */
8216 case SSH_STATE_INTERMED:
8217 ssh->size_needed = TRUE; /* buffer for later */
8219 case SSH_STATE_SESSION:
8220 if (!ssh->cfg.nopty) {
8221 if (ssh->version == 1) {
8222 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
8223 PKT_INT, ssh->term_height,
8224 PKT_INT, ssh->term_width,
8225 PKT_INT, 0, PKT_INT, 0, PKT_END);
8226 } else if (ssh->mainchan) {
8227 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8228 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
8229 ssh2_pkt_addstring(pktout, "window-change");
8230 ssh2_pkt_addbool(pktout, 0);
8231 ssh2_pkt_adduint32(pktout, ssh->term_width);
8232 ssh2_pkt_adduint32(pktout, ssh->term_height);
8233 ssh2_pkt_adduint32(pktout, 0);
8234 ssh2_pkt_adduint32(pktout, 0);
8235 ssh2_pkt_send(ssh, pktout);
8243 * Return a list of the special codes that make sense in this
8246 static const struct telnet_special *ssh_get_specials(void *handle)
8248 static const struct telnet_special ssh1_ignore_special[] = {
8249 {"IGNORE message", TS_NOP}
8251 static const struct telnet_special ssh2_transport_specials[] = {
8252 {"IGNORE message", TS_NOP},
8253 {"Repeat key exchange", TS_REKEY},
8255 static const struct telnet_special ssh2_session_specials[] = {
8258 /* These are the signal names defined by draft-ietf-secsh-connect-23.
8259 * They include all the ISO C signals, but are a subset of the POSIX
8260 * required signals. */
8261 {"SIGINT (Interrupt)", TS_SIGINT},
8262 {"SIGTERM (Terminate)", TS_SIGTERM},
8263 {"SIGKILL (Kill)", TS_SIGKILL},
8264 {"SIGQUIT (Quit)", TS_SIGQUIT},
8265 {"SIGHUP (Hangup)", TS_SIGHUP},
8266 {"More signals", TS_SUBMENU},
8267 {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM},
8268 {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL},
8269 {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV},
8270 {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2},
8273 static const struct telnet_special specials_end[] = {
8276 /* XXX review this length for any changes: */
8277 static struct telnet_special ssh_specials[lenof(ssh2_transport_specials) +
8278 lenof(ssh2_session_specials) +
8279 lenof(specials_end)];
8280 Ssh ssh = (Ssh) handle;
8282 #define ADD_SPECIALS(name) \
8284 assert((i + lenof(name)) <= lenof(ssh_specials)); \
8285 memcpy(&ssh_specials[i], name, sizeof name); \
8289 if (ssh->version == 1) {
8290 /* Don't bother offering IGNORE if we've decided the remote
8291 * won't cope with it, since we wouldn't bother sending it if
8293 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
8294 ADD_SPECIALS(ssh1_ignore_special);
8295 } else if (ssh->version == 2) {
8296 ADD_SPECIALS(ssh2_transport_specials);
8298 ADD_SPECIALS(ssh2_session_specials);
8299 } /* else we're not ready yet */
8302 ADD_SPECIALS(specials_end);
8303 return ssh_specials;
8311 * Send special codes. TS_EOF is useful for `plink', so you
8312 * can send an EOF and collect resulting output (e.g. `plink
8315 static void ssh_special(void *handle, Telnet_Special code)
8317 Ssh ssh = (Ssh) handle;
8318 struct Packet *pktout;
8320 if (code == TS_EOF) {
8321 if (ssh->state != SSH_STATE_SESSION) {
8323 * Buffer the EOF in case we are pre-SESSION, so we can
8324 * send it as soon as we reach SESSION.
8327 ssh->eof_needed = TRUE;
8330 if (ssh->version == 1) {
8331 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
8332 } else if (ssh->mainchan) {
8333 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
8334 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
8335 ssh2_pkt_send(ssh, pktout);
8336 ssh->send_ok = 0; /* now stop trying to read from stdin */
8338 logevent("Sent EOF message");
8339 } else if (code == TS_PING || code == TS_NOP) {
8340 if (ssh->state == SSH_STATE_CLOSED
8341 || ssh->state == SSH_STATE_PREPACKET) return;
8342 if (ssh->version == 1) {
8343 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
8344 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
8346 pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
8347 ssh2_pkt_addstring_start(pktout);
8348 ssh2_pkt_send_noqueue(ssh, pktout);
8350 } else if (code == TS_REKEY) {
8351 if (!ssh->kex_in_progress && ssh->version == 2) {
8352 do_ssh2_transport(ssh, "at user request", -1, NULL);
8354 } else if (code == TS_BRK) {
8355 if (ssh->state == SSH_STATE_CLOSED
8356 || ssh->state == SSH_STATE_PREPACKET) return;
8357 if (ssh->version == 1) {
8358 logevent("Unable to send BREAK signal in SSH-1");
8359 } else if (ssh->mainchan) {
8360 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8361 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
8362 ssh2_pkt_addstring(pktout, "break");
8363 ssh2_pkt_addbool(pktout, 0);
8364 ssh2_pkt_adduint32(pktout, 0); /* default break length */
8365 ssh2_pkt_send(ssh, pktout);
8368 /* Is is a POSIX signal? */
8369 char *signame = NULL;
8370 if (code == TS_SIGABRT) signame = "ABRT";
8371 if (code == TS_SIGALRM) signame = "ALRM";
8372 if (code == TS_SIGFPE) signame = "FPE";
8373 if (code == TS_SIGHUP) signame = "HUP";
8374 if (code == TS_SIGILL) signame = "ILL";
8375 if (code == TS_SIGINT) signame = "INT";
8376 if (code == TS_SIGKILL) signame = "KILL";
8377 if (code == TS_SIGPIPE) signame = "PIPE";
8378 if (code == TS_SIGQUIT) signame = "QUIT";
8379 if (code == TS_SIGSEGV) signame = "SEGV";
8380 if (code == TS_SIGTERM) signame = "TERM";
8381 if (code == TS_SIGUSR1) signame = "USR1";
8382 if (code == TS_SIGUSR2) signame = "USR2";
8383 /* The SSH-2 protocol does in principle support arbitrary named
8384 * signals, including signame@domain, but we don't support those. */
8386 /* It's a signal. */
8387 if (ssh->version == 2 && ssh->mainchan) {
8388 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8389 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
8390 ssh2_pkt_addstring(pktout, "signal");
8391 ssh2_pkt_addbool(pktout, 0);
8392 ssh2_pkt_addstring(pktout, signame);
8393 ssh2_pkt_send(ssh, pktout);
8394 logeventf(ssh, "Sent signal SIG%s", signame);
8397 /* Never heard of it. Do nothing */
8402 void *new_sock_channel(void *handle, Socket s)
8404 Ssh ssh = (Ssh) handle;
8405 struct ssh_channel *c;
8406 c = snew(struct ssh_channel);
8411 c->localid = alloc_channel_id(ssh);
8413 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
8415 bufchain_init(&c->v.v2.outbuffer);
8416 add234(ssh->channels, c);
8422 * This is called when stdout/stderr (the entity to which
8423 * from_backend sends data) manages to clear some backlog.
8425 static void ssh_unthrottle(void *handle, int bufsize)
8427 Ssh ssh = (Ssh) handle;
8428 if (ssh->version == 1) {
8429 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
8430 ssh->v1_stdout_throttling = 0;
8431 ssh1_throttle(ssh, -1);
8434 if (ssh->mainchan && ssh->mainchan->closes == 0)
8435 ssh2_set_window(ssh->mainchan, OUR_V2_WINSIZE - bufsize);
8439 void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
8441 struct ssh_channel *c = (struct ssh_channel *)channel;
8443 struct Packet *pktout;
8445 logeventf(ssh, "Opening forwarded connection to %s:%d", hostname, port);
8447 if (ssh->version == 1) {
8448 send_packet(ssh, SSH1_MSG_PORT_OPEN,
8449 PKT_INT, c->localid,
8452 /* PKT_STR, <org:orgport>, */
8455 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
8456 ssh2_pkt_addstring(pktout, "direct-tcpip");
8457 ssh2_pkt_adduint32(pktout, c->localid);
8458 c->v.v2.locwindow = OUR_V2_WINSIZE;
8459 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */
8460 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
8461 ssh2_pkt_addstring(pktout, hostname);
8462 ssh2_pkt_adduint32(pktout, port);
8464 * We make up values for the originator data; partly it's
8465 * too much hassle to keep track, and partly I'm not
8466 * convinced the server should be told details like that
8467 * about my local network configuration.
8469 ssh2_pkt_addstring(pktout, "client-side-connection");
8470 ssh2_pkt_adduint32(pktout, 0);
8471 ssh2_pkt_send(ssh, pktout);
8475 static Socket ssh_socket(void *handle)
8477 Ssh ssh = (Ssh) handle;
8481 static int ssh_sendok(void *handle)
8483 Ssh ssh = (Ssh) handle;
8484 return ssh->send_ok;
8487 static int ssh_ldisc(void *handle, int option)
8489 Ssh ssh = (Ssh) handle;
8490 if (option == LD_ECHO)
8491 return ssh->echoing;
8492 if (option == LD_EDIT)
8493 return ssh->editing;
8497 static void ssh_provide_ldisc(void *handle, void *ldisc)
8499 Ssh ssh = (Ssh) handle;
8503 static void ssh_provide_logctx(void *handle, void *logctx)
8505 Ssh ssh = (Ssh) handle;
8506 ssh->logctx = logctx;
8509 static int ssh_return_exitcode(void *handle)
8511 Ssh ssh = (Ssh) handle;
8515 return (ssh->exitcode >= 0 ? ssh->exitcode : 0);
8519 * cfg_info for SSH is the currently running version of the
8520 * protocol. (1 for 1; 2 for 2; 0 for not-decided-yet.)
8522 static int ssh_cfg_info(void *handle)
8524 Ssh ssh = (Ssh) handle;
8525 return ssh->version;
8529 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
8530 * that fails. This variable is the means by which scp.c can reach
8531 * into the SSH code and find out which one it got.
8533 extern int ssh_fallback_cmd(void *handle)
8535 Ssh ssh = (Ssh) handle;
8536 return ssh->fallback_cmd;
8539 Backend ssh_backend = {
8549 ssh_return_exitcode,