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3c0ef626 | 1 | /* |
2 | * Copyright (c) 2000 Markus Friedl. All rights reserved. | |
3 | * | |
4 | * Redistribution and use in source and binary forms, with or without | |
5 | * modification, are permitted provided that the following conditions | |
6 | * are met: | |
7 | * 1. Redistributions of source code must retain the above copyright | |
8 | * notice, this list of conditions and the following disclaimer. | |
9 | * 2. Redistributions in binary form must reproduce the above copyright | |
10 | * notice, this list of conditions and the following disclaimer in the | |
11 | * documentation and/or other materials provided with the distribution. | |
12 | * | |
13 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR | |
14 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES | |
15 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. | |
16 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, | |
17 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT | |
18 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, | |
19 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY | |
20 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT | |
21 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF | |
22 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | |
23 | */ | |
24 | ||
25 | #include "includes.h" | |
1e608e42 | 26 | RCSID("$OpenBSD: sshconnect2.c,v 1.97 2002/02/25 16:33:27 markus Exp $"); |
3c0ef626 | 27 | |
28 | #include "ssh.h" | |
29 | #include "ssh2.h" | |
30 | #include "xmalloc.h" | |
3c0ef626 | 31 | #include "buffer.h" |
32 | #include "packet.h" | |
3c0ef626 | 33 | #include "compat.h" |
34 | #include "bufaux.h" | |
35 | #include "cipher.h" | |
36 | #include "kex.h" | |
37 | #include "myproposal.h" | |
3c0ef626 | 38 | #include "sshconnect.h" |
39 | #include "authfile.h" | |
40 | #include "dh.h" | |
41 | #include "authfd.h" | |
42 | #include "log.h" | |
43 | #include "readconf.h" | |
44 | #include "readpass.h" | |
45 | #include "match.h" | |
46 | #include "dispatch.h" | |
47 | #include "canohost.h" | |
48 | ||
5598e598 | 49 | #ifdef GSSAPI |
50 | #include "ssh-gss.h" | |
51 | #endif | |
52 | ||
3c0ef626 | 53 | /* import */ |
54 | extern char *client_version_string; | |
55 | extern char *server_version_string; | |
56 | extern Options options; | |
57 | ||
58 | /* | |
59 | * SSH2 key exchange | |
60 | */ | |
61 | ||
62 | u_char *session_id2 = NULL; | |
63 | int session_id2_len = 0; | |
64 | ||
65 | char *xxx_host; | |
66 | struct sockaddr *xxx_hostaddr; | |
67 | ||
68 | Kex *xxx_kex = NULL; | |
69 | ||
70 | static int | |
71 | verify_host_key_callback(Key *hostkey) | |
72 | { | |
73 | if (verify_host_key(xxx_host, xxx_hostaddr, hostkey) == -1) | |
74 | fatal("Host key verification failed."); | |
75 | return 0; | |
76 | } | |
77 | ||
78 | void | |
79 | ssh_kex2(char *host, struct sockaddr *hostaddr) | |
80 | { | |
81 | Kex *kex; | |
1e608e42 | 82 | #ifdef GSSAPI |
83 | char *orig, *gss; | |
84 | int len; | |
85 | #endif | |
3c0ef626 | 86 | |
87 | xxx_host = host; | |
88 | xxx_hostaddr = hostaddr; | |
89 | ||
5598e598 | 90 | #ifdef GSSAPI |
1e608e42 | 91 | /* Add the GSSAPI mechanisms currently supported on this client to |
92 | * the key exchange algorithm proposal */ | |
93 | orig = myproposal[PROPOSAL_KEX_ALGS]; | |
94 | gss = ssh_gssapi_mechanisms(0,host); | |
95 | if (gss) { | |
96 | len = strlen(orig)+strlen(gss)+2; | |
97 | myproposal[PROPOSAL_KEX_ALGS]=xmalloc(len); | |
98 | snprintf(myproposal[PROPOSAL_KEX_ALGS],len,"%s,%s",gss,orig); | |
5598e598 | 99 | } |
100 | #endif | |
101 | ||
3c0ef626 | 102 | if (options.ciphers == (char *)-1) { |
103 | log("No valid ciphers for protocol version 2 given, using defaults."); | |
104 | options.ciphers = NULL; | |
105 | } | |
106 | if (options.ciphers != NULL) { | |
107 | myproposal[PROPOSAL_ENC_ALGS_CTOS] = | |
108 | myproposal[PROPOSAL_ENC_ALGS_STOC] = options.ciphers; | |
109 | } | |
110 | myproposal[PROPOSAL_ENC_ALGS_CTOS] = | |
111 | compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_CTOS]); | |
112 | myproposal[PROPOSAL_ENC_ALGS_STOC] = | |
113 | compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_STOC]); | |
114 | if (options.compression) { | |
115 | myproposal[PROPOSAL_COMP_ALGS_CTOS] = | |
116 | myproposal[PROPOSAL_COMP_ALGS_STOC] = "zlib"; | |
117 | } else { | |
118 | myproposal[PROPOSAL_COMP_ALGS_CTOS] = | |
119 | myproposal[PROPOSAL_COMP_ALGS_STOC] = "none"; | |
120 | } | |
121 | if (options.macs != NULL) { | |
122 | myproposal[PROPOSAL_MAC_ALGS_CTOS] = | |
123 | myproposal[PROPOSAL_MAC_ALGS_STOC] = options.macs; | |
124 | } | |
125 | if (options.hostkeyalgorithms != NULL) | |
1e608e42 | 126 | myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = |
3c0ef626 | 127 | options.hostkeyalgorithms; |
128 | ||
1e608e42 | 129 | #ifdef GSSAPI |
130 | /* If we've got GSSAPI algorithms, then we also support the | |
131 | * 'null' hostkey, as a last resort */ | |
132 | if (gss) { | |
133 | orig=myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS]; | |
134 | len = strlen(orig)+sizeof(",null"); | |
135 | myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS]=xmalloc(len); | |
136 | snprintf(myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS],len,"%s,null",orig); | |
137 | } | |
138 | #endif | |
139 | ||
3c0ef626 | 140 | /* start key exchange */ |
141 | kex = kex_setup(myproposal); | |
142 | kex->client_version_string=client_version_string; | |
143 | kex->server_version_string=server_version_string; | |
144 | kex->verify_host_key=&verify_host_key_callback; | |
5598e598 | 145 | kex->host=host; |
146 | ||
147 | #ifdef GSSAPI | |
148 | kex->options.gss_deleg_creds=options.gss_deleg_creds; | |
149 | #endif | |
3c0ef626 | 150 | |
151 | xxx_kex = kex; | |
152 | ||
153 | dispatch_run(DISPATCH_BLOCK, &kex->done, kex); | |
154 | ||
155 | session_id2 = kex->session_id; | |
156 | session_id2_len = kex->session_id_len; | |
157 | ||
158 | #ifdef DEBUG_KEXDH | |
159 | /* send 1st encrypted/maced/compressed message */ | |
160 | packet_start(SSH2_MSG_IGNORE); | |
161 | packet_put_cstring("markus"); | |
162 | packet_send(); | |
163 | packet_write_wait(); | |
164 | #endif | |
165 | debug("done: ssh_kex2."); | |
166 | } | |
167 | ||
168 | /* | |
169 | * Authenticate user | |
170 | */ | |
171 | ||
172 | typedef struct Authctxt Authctxt; | |
173 | typedef struct Authmethod Authmethod; | |
174 | ||
175 | typedef int sign_cb_fn( | |
176 | Authctxt *authctxt, Key *key, | |
1e608e42 | 177 | u_char **sigp, u_int *lenp, u_char *data, u_int datalen); |
3c0ef626 | 178 | |
179 | struct Authctxt { | |
180 | const char *server_user; | |
181 | const char *local_user; | |
182 | const char *host; | |
183 | const char *service; | |
184 | Authmethod *method; | |
185 | int success; | |
186 | char *authlist; | |
187 | /* pubkey */ | |
188 | Key *last_key; | |
189 | sign_cb_fn *last_key_sign; | |
190 | int last_key_hint; | |
191 | AuthenticationConnection *agent; | |
192 | /* hostbased */ | |
193 | Key **keys; | |
194 | int nkeys; | |
195 | /* kbd-interactive */ | |
196 | int info_req_seen; | |
5598e598 | 197 | /* generic */ |
198 | void *methoddata; | |
3c0ef626 | 199 | }; |
200 | struct Authmethod { | |
201 | char *name; /* string to compare against server's list */ | |
202 | int (*userauth)(Authctxt *authctxt); | |
203 | int *enabled; /* flag in option struct that enables method */ | |
204 | int *batch_flag; /* flag in option struct that disables method */ | |
205 | }; | |
206 | ||
1e608e42 | 207 | void input_userauth_success(int, u_int32_t, void *); |
208 | void input_userauth_failure(int, u_int32_t, void *); | |
209 | void input_userauth_banner(int, u_int32_t, void *); | |
210 | void input_userauth_error(int, u_int32_t, void *); | |
211 | void input_userauth_info_req(int, u_int32_t, void *); | |
212 | void input_userauth_pk_ok(int, u_int32_t, void *); | |
3c0ef626 | 213 | |
1e608e42 | 214 | int userauth_none(Authctxt *); |
215 | int userauth_pubkey(Authctxt *); | |
216 | int userauth_passwd(Authctxt *); | |
217 | int userauth_kbdint(Authctxt *); | |
218 | int userauth_hostbased(Authctxt *); | |
3c0ef626 | 219 | |
5598e598 | 220 | #ifdef GSSAPI |
1e608e42 | 221 | int userauth_external(Authctxt *authctxt); |
222 | int userauth_gssapi(Authctxt *authctxt); | |
223 | void input_gssapi_response(int type, u_int32_t plen, void *ctxt); | |
224 | void input_gssapi_token(int type, u_int32_t plen, void *ctxt); | |
225 | void input_gssapi_hash(int type, u_int32_t plen, void *ctxt); | |
5598e598 | 226 | #endif |
227 | ||
1e608e42 | 228 | void userauth(Authctxt *, char *); |
3c0ef626 | 229 | |
230 | static int sign_and_send_pubkey(Authctxt *, Key *, sign_cb_fn *); | |
231 | static void clear_auth_state(Authctxt *); | |
232 | ||
233 | static Authmethod *authmethod_get(char *authlist); | |
234 | static Authmethod *authmethod_lookup(const char *name); | |
235 | static char *authmethods_get(void); | |
236 | ||
237 | Authmethod authmethods[] = { | |
5598e598 | 238 | #ifdef GSSAPI |
239 | {"external-keyx", | |
240 | userauth_external, | |
241 | &options.gss_authentication, | |
242 | NULL}, | |
243 | {"gssapi", | |
244 | userauth_gssapi, | |
245 | &options.gss_authentication, | |
246 | NULL}, | |
247 | #endif | |
3c0ef626 | 248 | {"hostbased", |
249 | userauth_hostbased, | |
250 | &options.hostbased_authentication, | |
251 | NULL}, | |
252 | {"publickey", | |
253 | userauth_pubkey, | |
254 | &options.pubkey_authentication, | |
255 | NULL}, | |
256 | {"keyboard-interactive", | |
257 | userauth_kbdint, | |
258 | &options.kbd_interactive_authentication, | |
259 | &options.batch_mode}, | |
260 | {"password", | |
261 | userauth_passwd, | |
262 | &options.password_authentication, | |
263 | &options.batch_mode}, | |
264 | {"none", | |
265 | userauth_none, | |
266 | NULL, | |
267 | NULL}, | |
268 | {NULL, NULL, NULL, NULL} | |
269 | }; | |
270 | ||
271 | void | |
272 | ssh_userauth2(const char *local_user, const char *server_user, char *host, | |
273 | Key **keys, int nkeys) | |
274 | { | |
275 | Authctxt authctxt; | |
276 | int type; | |
3c0ef626 | 277 | |
278 | if (options.challenge_response_authentication) | |
279 | options.kbd_interactive_authentication = 1; | |
280 | ||
281 | debug("send SSH2_MSG_SERVICE_REQUEST"); | |
282 | packet_start(SSH2_MSG_SERVICE_REQUEST); | |
283 | packet_put_cstring("ssh-userauth"); | |
284 | packet_send(); | |
285 | packet_write_wait(); | |
1e608e42 | 286 | type = packet_read(); |
3c0ef626 | 287 | if (type != SSH2_MSG_SERVICE_ACCEPT) { |
288 | fatal("denied SSH2_MSG_SERVICE_ACCEPT: %d", type); | |
289 | } | |
290 | if (packet_remaining() > 0) { | |
1e608e42 | 291 | char *reply = packet_get_string(NULL); |
3c0ef626 | 292 | debug("service_accept: %s", reply); |
293 | xfree(reply); | |
294 | } else { | |
295 | debug("buggy server: service_accept w/o service"); | |
296 | } | |
1e608e42 | 297 | packet_check_eom(); |
3c0ef626 | 298 | debug("got SSH2_MSG_SERVICE_ACCEPT"); |
299 | ||
300 | if (options.preferred_authentications == NULL) | |
301 | options.preferred_authentications = authmethods_get(); | |
302 | ||
303 | /* setup authentication context */ | |
304 | memset(&authctxt, 0, sizeof(authctxt)); | |
305 | authctxt.agent = ssh_get_authentication_connection(); | |
306 | authctxt.server_user = server_user; | |
307 | authctxt.local_user = local_user; | |
308 | authctxt.host = host; | |
309 | authctxt.service = "ssh-connection"; /* service name */ | |
310 | authctxt.success = 0; | |
311 | authctxt.method = authmethod_lookup("none"); | |
312 | authctxt.authlist = NULL; | |
5598e598 | 313 | authctxt.methoddata = NULL; |
3c0ef626 | 314 | authctxt.keys = keys; |
315 | authctxt.nkeys = nkeys; | |
316 | authctxt.info_req_seen = 0; | |
317 | if (authctxt.method == NULL) | |
318 | fatal("ssh_userauth2: internal error: cannot send userauth none request"); | |
319 | ||
320 | /* initial userauth request */ | |
321 | userauth_none(&authctxt); | |
322 | ||
323 | dispatch_init(&input_userauth_error); | |
324 | dispatch_set(SSH2_MSG_USERAUTH_SUCCESS, &input_userauth_success); | |
325 | dispatch_set(SSH2_MSG_USERAUTH_FAILURE, &input_userauth_failure); | |
326 | dispatch_set(SSH2_MSG_USERAUTH_BANNER, &input_userauth_banner); | |
327 | dispatch_run(DISPATCH_BLOCK, &authctxt.success, &authctxt); /* loop until success */ | |
328 | ||
329 | if (authctxt.agent != NULL) | |
330 | ssh_close_authentication_connection(authctxt.agent); | |
331 | ||
332 | debug("ssh-userauth2 successful: method %s", authctxt.method->name); | |
333 | } | |
334 | void | |
335 | userauth(Authctxt *authctxt, char *authlist) | |
336 | { | |
5598e598 | 337 | if (authctxt->methoddata!=NULL) { |
338 | xfree(authctxt->methoddata); | |
339 | authctxt->methoddata=NULL; | |
340 | } | |
341 | ||
3c0ef626 | 342 | if (authlist == NULL) { |
343 | authlist = authctxt->authlist; | |
344 | } else { | |
345 | if (authctxt->authlist) | |
346 | xfree(authctxt->authlist); | |
347 | authctxt->authlist = authlist; | |
348 | } | |
349 | for (;;) { | |
350 | Authmethod *method = authmethod_get(authlist); | |
351 | if (method == NULL) | |
352 | fatal("Permission denied (%s).", authlist); | |
353 | authctxt->method = method; | |
354 | if (method->userauth(authctxt) != 0) { | |
355 | debug2("we sent a %s packet, wait for reply", method->name); | |
356 | break; | |
357 | } else { | |
358 | debug2("we did not send a packet, disable method"); | |
359 | method->enabled = NULL; | |
360 | } | |
361 | } | |
362 | } | |
363 | void | |
1e608e42 | 364 | input_userauth_error(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 365 | { |
366 | fatal("input_userauth_error: bad message during authentication: " | |
367 | "type %d", type); | |
368 | } | |
369 | void | |
1e608e42 | 370 | input_userauth_banner(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 371 | { |
372 | char *msg, *lang; | |
373 | debug3("input_userauth_banner"); | |
374 | msg = packet_get_string(NULL); | |
375 | lang = packet_get_string(NULL); | |
376 | fprintf(stderr, "%s", msg); | |
377 | xfree(msg); | |
378 | xfree(lang); | |
379 | } | |
380 | void | |
1e608e42 | 381 | input_userauth_success(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 382 | { |
383 | Authctxt *authctxt = ctxt; | |
384 | if (authctxt == NULL) | |
385 | fatal("input_userauth_success: no authentication context"); | |
386 | if (authctxt->authlist) | |
387 | xfree(authctxt->authlist); | |
5598e598 | 388 | if (authctxt->methoddata) |
389 | xfree(authctxt->methoddata); | |
3c0ef626 | 390 | clear_auth_state(authctxt); |
391 | authctxt->success = 1; /* break out */ | |
392 | } | |
393 | void | |
1e608e42 | 394 | input_userauth_failure(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 395 | { |
396 | Authctxt *authctxt = ctxt; | |
397 | char *authlist = NULL; | |
398 | int partial; | |
399 | ||
400 | if (authctxt == NULL) | |
401 | fatal("input_userauth_failure: no authentication context"); | |
402 | ||
403 | authlist = packet_get_string(NULL); | |
404 | partial = packet_get_char(); | |
1e608e42 | 405 | packet_check_eom(); |
3c0ef626 | 406 | |
407 | if (partial != 0) | |
408 | log("Authenticated with partial success."); | |
409 | debug("authentications that can continue: %s", authlist); | |
410 | ||
411 | clear_auth_state(authctxt); | |
412 | userauth(authctxt, authlist); | |
413 | } | |
414 | void | |
1e608e42 | 415 | input_userauth_pk_ok(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 416 | { |
417 | Authctxt *authctxt = ctxt; | |
418 | Key *key = NULL; | |
419 | Buffer b; | |
1e608e42 | 420 | int pktype, sent = 0; |
421 | u_int alen, blen; | |
422 | char *pkalg, *fp; | |
423 | u_char *pkblob; | |
3c0ef626 | 424 | |
425 | if (authctxt == NULL) | |
426 | fatal("input_userauth_pk_ok: no authentication context"); | |
427 | if (datafellows & SSH_BUG_PKOK) { | |
428 | /* this is similar to SSH_BUG_PKAUTH */ | |
429 | debug2("input_userauth_pk_ok: SSH_BUG_PKOK"); | |
430 | pkblob = packet_get_string(&blen); | |
431 | buffer_init(&b); | |
432 | buffer_append(&b, pkblob, blen); | |
433 | pkalg = buffer_get_string(&b, &alen); | |
434 | buffer_free(&b); | |
435 | } else { | |
436 | pkalg = packet_get_string(&alen); | |
437 | pkblob = packet_get_string(&blen); | |
438 | } | |
1e608e42 | 439 | packet_check_eom(); |
3c0ef626 | 440 | |
441 | debug("input_userauth_pk_ok: pkalg %s blen %d lastkey %p hint %d", | |
442 | pkalg, blen, authctxt->last_key, authctxt->last_key_hint); | |
443 | ||
444 | do { | |
445 | if (authctxt->last_key == NULL || | |
446 | authctxt->last_key_sign == NULL) { | |
447 | debug("no last key or no sign cb"); | |
448 | break; | |
449 | } | |
1e608e42 | 450 | if ((pktype = key_type_from_name(pkalg)) == KEY_UNSPEC) { |
3c0ef626 | 451 | debug("unknown pkalg %s", pkalg); |
452 | break; | |
453 | } | |
454 | if ((key = key_from_blob(pkblob, blen)) == NULL) { | |
455 | debug("no key from blob. pkalg %s", pkalg); | |
456 | break; | |
457 | } | |
1e608e42 | 458 | if (key->type != pktype) { |
459 | error("input_userauth_pk_ok: type mismatch " | |
460 | "for decoded key (received %d, expected %d)", | |
461 | key->type, pktype); | |
462 | break; | |
463 | } | |
3c0ef626 | 464 | fp = key_fingerprint(key, SSH_FP_MD5, SSH_FP_HEX); |
465 | debug2("input_userauth_pk_ok: fp %s", fp); | |
466 | xfree(fp); | |
467 | if (!key_equal(key, authctxt->last_key)) { | |
468 | debug("key != last_key"); | |
469 | break; | |
470 | } | |
471 | sent = sign_and_send_pubkey(authctxt, key, | |
472 | authctxt->last_key_sign); | |
1e608e42 | 473 | } while (0); |
3c0ef626 | 474 | |
475 | if (key != NULL) | |
476 | key_free(key); | |
477 | xfree(pkalg); | |
478 | xfree(pkblob); | |
479 | ||
480 | /* unregister */ | |
481 | clear_auth_state(authctxt); | |
482 | dispatch_set(SSH2_MSG_USERAUTH_PK_OK, NULL); | |
483 | ||
484 | /* try another method if we did not send a packet*/ | |
485 | if (sent == 0) | |
486 | userauth(authctxt, NULL); | |
487 | ||
488 | } | |
489 | ||
5598e598 | 490 | #ifdef GSSAPI |
491 | int | |
492 | userauth_gssapi(Authctxt *authctxt) | |
493 | { | |
494 | int i; | |
495 | Gssctxt *gssctxt; | |
496 | static int tries=0; | |
497 | ||
498 | /* For now, we only make one attempt at this. We could try offering | |
499 | * the server different GSSAPI OIDs until we get bored, I suppose. | |
500 | */ | |
501 | if (tries++>0) return 0; | |
502 | ||
1e608e42 | 503 | if (datafellows & SSH_OLD_GSSAPI) return 0; |
504 | ||
5598e598 | 505 | gssctxt=xmalloc(sizeof(Gssctxt)); |
506 | ||
507 | /* Initialise as much of our context as we can, so failures can be | |
508 | * trapped before sending any packets. | |
509 | */ | |
510 | ssh_gssapi_build_ctx(gssctxt); | |
511 | if (ssh_gssapi_import_name(gssctxt,authctxt->host)) { | |
512 | return(0); | |
513 | } | |
514 | authctxt->methoddata=(void *)gssctxt; | |
515 | ||
516 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
517 | packet_put_cstring(authctxt->server_user); | |
518 | packet_put_cstring(authctxt->service); | |
519 | packet_put_cstring(authctxt->method->name); | |
520 | ||
521 | /* FIXME: This assumes that our current GSSAPI implementation | |
522 | * supports all of the mechanisms listed in supported_mechs. | |
523 | * This may not be the case - we should use something along | |
524 | * the lines of the code in gss_genr to remove the ones that | |
525 | * aren't supported */ | |
526 | packet_put_int(GSS_LAST_ENTRY); | |
527 | for (i=0;i<GSS_LAST_ENTRY;i++) { | |
528 | packet_put_string(supported_mechs[i].oid.elements, | |
529 | supported_mechs[i].oid.length); | |
530 | } | |
531 | packet_send(); | |
532 | packet_write_wait(); | |
533 | ||
534 | dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE,&input_gssapi_response); | |
535 | dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN,&input_gssapi_token); | |
536 | ||
537 | return 1; | |
538 | } | |
539 | ||
540 | void | |
1e608e42 | 541 | input_gssapi_response(int type, u_int32_t plen, void *ctxt) |
5598e598 | 542 | { |
543 | Authctxt *authctxt = ctxt; | |
544 | Gssctxt *gssctxt; | |
545 | OM_uint32 status,ms; | |
546 | int oidlen; | |
547 | char *oidv; | |
548 | gss_buffer_desc send_tok; | |
549 | ||
550 | if (authctxt == NULL) | |
551 | fatal("input_gssapi_response: no authentication context"); | |
552 | gssctxt = authctxt->methoddata; | |
553 | ||
554 | /* Setup our OID */ | |
555 | oidv=packet_get_string(&oidlen); | |
556 | ssh_gssapi_set_oid_data(gssctxt,oidv,oidlen); | |
557 | ||
1e608e42 | 558 | packet_check_eom(); |
5598e598 | 559 | |
560 | status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds, | |
561 | GSS_C_NO_BUFFER, &send_tok, | |
562 | NULL); | |
563 | if (GSS_ERROR(status)) { | |
564 | /* Start again with next method on list */ | |
565 | debug("Trying to start again"); | |
566 | userauth(authctxt,NULL); | |
567 | return; | |
568 | } | |
569 | ||
570 | /* We must have data to send */ | |
571 | packet_start(SSH2_MSG_USERAUTH_GSSAPI_TOKEN); | |
572 | packet_put_string(send_tok.value,send_tok.length); | |
573 | packet_send(); | |
574 | packet_write_wait(); | |
575 | gss_release_buffer(&ms, &send_tok); | |
576 | } | |
577 | ||
578 | void | |
1e608e42 | 579 | input_gssapi_token(int type, u_int32_t plen, void *ctxt) |
5598e598 | 580 | { |
581 | Authctxt *authctxt = ctxt; | |
582 | Gssctxt *gssctxt; | |
583 | gss_buffer_desc send_tok,recv_tok; | |
584 | OM_uint32 status; | |
585 | ||
586 | if (authctxt == NULL) | |
587 | fatal("input_gssapi_response: no authentication context"); | |
588 | gssctxt = authctxt->methoddata; | |
589 | ||
590 | recv_tok.value=packet_get_string(&recv_tok.length); | |
591 | ||
592 | status=ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds, | |
593 | &recv_tok, &send_tok, NULL); | |
594 | ||
1e608e42 | 595 | packet_check_eom(); |
5598e598 | 596 | |
597 | if (GSS_ERROR(status)) { | |
598 | /* Start again with the next method in the list */ | |
599 | userauth(authctxt,NULL); | |
600 | return; | |
601 | } | |
602 | ||
603 | if (send_tok.length>0) { | |
604 | packet_start(SSH2_MSG_USERAUTH_GSSAPI_TOKEN); | |
605 | packet_put_string(send_tok.value,send_tok.length); | |
606 | packet_send(); | |
607 | packet_write_wait(); | |
608 | } | |
609 | ||
610 | if (status == GSS_S_COMPLETE) { | |
611 | /* If that succeeded, send a exchange complete message */ | |
612 | packet_start(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE); | |
613 | packet_send(); | |
614 | packet_write_wait(); | |
615 | } | |
616 | } | |
617 | ||
618 | int | |
619 | userauth_external(Authctxt *authctxt) | |
620 | { | |
621 | static int attempt =0; | |
622 | ||
623 | if (attempt++ >= 1) | |
624 | return 0; | |
625 | ||
626 | debug2("userauth_external"); | |
627 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
628 | packet_put_cstring(authctxt->server_user); | |
629 | packet_put_cstring(authctxt->service); | |
630 | packet_put_cstring(authctxt->method->name); | |
631 | packet_send(); | |
632 | packet_write_wait(); | |
633 | return 1; | |
634 | } | |
635 | #endif /* GSSAPI */ | |
636 | ||
3c0ef626 | 637 | int |
638 | userauth_none(Authctxt *authctxt) | |
639 | { | |
640 | /* initial userauth request */ | |
641 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
642 | packet_put_cstring(authctxt->server_user); | |
643 | packet_put_cstring(authctxt->service); | |
644 | packet_put_cstring(authctxt->method->name); | |
645 | packet_send(); | |
646 | return 1; | |
5598e598 | 647 | |
3c0ef626 | 648 | } |
649 | ||
650 | int | |
651 | userauth_passwd(Authctxt *authctxt) | |
652 | { | |
653 | static int attempt = 0; | |
654 | char prompt[80]; | |
655 | char *password; | |
656 | ||
657 | if (attempt++ >= options.number_of_password_prompts) | |
658 | return 0; | |
659 | ||
1e608e42 | 660 | if (attempt != 1) |
3c0ef626 | 661 | error("Permission denied, please try again."); |
662 | ||
663 | snprintf(prompt, sizeof(prompt), "%.30s@%.128s's password: ", | |
664 | authctxt->server_user, authctxt->host); | |
665 | password = read_passphrase(prompt, 0); | |
666 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
667 | packet_put_cstring(authctxt->server_user); | |
668 | packet_put_cstring(authctxt->service); | |
669 | packet_put_cstring(authctxt->method->name); | |
670 | packet_put_char(0); | |
671 | packet_put_cstring(password); | |
672 | memset(password, 0, strlen(password)); | |
673 | xfree(password); | |
674 | packet_add_padding(64); | |
675 | packet_send(); | |
676 | return 1; | |
677 | } | |
678 | ||
679 | static void | |
680 | clear_auth_state(Authctxt *authctxt) | |
681 | { | |
682 | /* XXX clear authentication state */ | |
683 | if (authctxt->last_key != NULL && authctxt->last_key_hint == -1) { | |
684 | debug3("clear_auth_state: key_free %p", authctxt->last_key); | |
685 | key_free(authctxt->last_key); | |
686 | } | |
687 | authctxt->last_key = NULL; | |
688 | authctxt->last_key_hint = -2; | |
689 | authctxt->last_key_sign = NULL; | |
690 | } | |
691 | ||
692 | static int | |
693 | sign_and_send_pubkey(Authctxt *authctxt, Key *k, sign_cb_fn *sign_callback) | |
694 | { | |
695 | Buffer b; | |
696 | u_char *blob, *signature; | |
1e608e42 | 697 | u_int bloblen, slen; |
3c0ef626 | 698 | int skip = 0; |
699 | int ret = -1; | |
700 | int have_sig = 1; | |
701 | ||
702 | debug3("sign_and_send_pubkey"); | |
703 | ||
704 | if (key_to_blob(k, &blob, &bloblen) == 0) { | |
705 | /* we cannot handle this key */ | |
706 | debug3("sign_and_send_pubkey: cannot handle key"); | |
707 | return 0; | |
708 | } | |
709 | /* data to be signed */ | |
710 | buffer_init(&b); | |
711 | if (datafellows & SSH_OLD_SESSIONID) { | |
712 | buffer_append(&b, session_id2, session_id2_len); | |
713 | skip = session_id2_len; | |
714 | } else { | |
715 | buffer_put_string(&b, session_id2, session_id2_len); | |
716 | skip = buffer_len(&b); | |
717 | } | |
718 | buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST); | |
719 | buffer_put_cstring(&b, authctxt->server_user); | |
720 | buffer_put_cstring(&b, | |
721 | datafellows & SSH_BUG_PKSERVICE ? | |
722 | "ssh-userauth" : | |
723 | authctxt->service); | |
724 | if (datafellows & SSH_BUG_PKAUTH) { | |
725 | buffer_put_char(&b, have_sig); | |
726 | } else { | |
727 | buffer_put_cstring(&b, authctxt->method->name); | |
728 | buffer_put_char(&b, have_sig); | |
729 | buffer_put_cstring(&b, key_ssh_name(k)); | |
730 | } | |
731 | buffer_put_string(&b, blob, bloblen); | |
732 | ||
733 | /* generate signature */ | |
734 | ret = (*sign_callback)(authctxt, k, &signature, &slen, | |
735 | buffer_ptr(&b), buffer_len(&b)); | |
736 | if (ret == -1) { | |
737 | xfree(blob); | |
738 | buffer_free(&b); | |
739 | return 0; | |
740 | } | |
741 | #ifdef DEBUG_PK | |
742 | buffer_dump(&b); | |
743 | #endif | |
744 | if (datafellows & SSH_BUG_PKSERVICE) { | |
745 | buffer_clear(&b); | |
746 | buffer_append(&b, session_id2, session_id2_len); | |
747 | skip = session_id2_len; | |
748 | buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST); | |
749 | buffer_put_cstring(&b, authctxt->server_user); | |
750 | buffer_put_cstring(&b, authctxt->service); | |
751 | buffer_put_cstring(&b, authctxt->method->name); | |
752 | buffer_put_char(&b, have_sig); | |
753 | if (!(datafellows & SSH_BUG_PKAUTH)) | |
754 | buffer_put_cstring(&b, key_ssh_name(k)); | |
755 | buffer_put_string(&b, blob, bloblen); | |
756 | } | |
757 | xfree(blob); | |
758 | ||
759 | /* append signature */ | |
760 | buffer_put_string(&b, signature, slen); | |
761 | xfree(signature); | |
762 | ||
763 | /* skip session id and packet type */ | |
764 | if (buffer_len(&b) < skip + 1) | |
765 | fatal("userauth_pubkey: internal error"); | |
766 | buffer_consume(&b, skip + 1); | |
767 | ||
768 | /* put remaining data from buffer into packet */ | |
769 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
770 | packet_put_raw(buffer_ptr(&b), buffer_len(&b)); | |
771 | buffer_free(&b); | |
772 | packet_send(); | |
773 | ||
774 | return 1; | |
775 | } | |
776 | ||
777 | static int | |
778 | send_pubkey_test(Authctxt *authctxt, Key *k, sign_cb_fn *sign_callback, | |
779 | int hint) | |
780 | { | |
781 | u_char *blob; | |
1e608e42 | 782 | u_int bloblen, have_sig = 0; |
3c0ef626 | 783 | |
784 | debug3("send_pubkey_test"); | |
785 | ||
786 | if (key_to_blob(k, &blob, &bloblen) == 0) { | |
787 | /* we cannot handle this key */ | |
788 | debug3("send_pubkey_test: cannot handle key"); | |
789 | return 0; | |
790 | } | |
791 | /* register callback for USERAUTH_PK_OK message */ | |
792 | authctxt->last_key_sign = sign_callback; | |
793 | authctxt->last_key_hint = hint; | |
794 | authctxt->last_key = k; | |
795 | dispatch_set(SSH2_MSG_USERAUTH_PK_OK, &input_userauth_pk_ok); | |
796 | ||
797 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
798 | packet_put_cstring(authctxt->server_user); | |
799 | packet_put_cstring(authctxt->service); | |
800 | packet_put_cstring(authctxt->method->name); | |
801 | packet_put_char(have_sig); | |
802 | if (!(datafellows & SSH_BUG_PKAUTH)) | |
803 | packet_put_cstring(key_ssh_name(k)); | |
804 | packet_put_string(blob, bloblen); | |
805 | xfree(blob); | |
806 | packet_send(); | |
807 | return 1; | |
808 | } | |
809 | ||
810 | static Key * | |
811 | load_identity_file(char *filename) | |
812 | { | |
813 | Key *private; | |
814 | char prompt[300], *passphrase; | |
815 | int quit, i; | |
816 | struct stat st; | |
817 | ||
818 | if (stat(filename, &st) < 0) { | |
819 | debug3("no such identity: %s", filename); | |
820 | return NULL; | |
821 | } | |
822 | private = key_load_private_type(KEY_UNSPEC, filename, "", NULL); | |
823 | if (private == NULL) { | |
824 | if (options.batch_mode) | |
825 | return NULL; | |
826 | snprintf(prompt, sizeof prompt, | |
1e608e42 | 827 | "Enter passphrase for key '%.100s': ", filename); |
3c0ef626 | 828 | for (i = 0; i < options.number_of_password_prompts; i++) { |
829 | passphrase = read_passphrase(prompt, 0); | |
830 | if (strcmp(passphrase, "") != 0) { | |
831 | private = key_load_private_type(KEY_UNSPEC, filename, | |
832 | passphrase, NULL); | |
833 | quit = 0; | |
834 | } else { | |
835 | debug2("no passphrase given, try next key"); | |
836 | quit = 1; | |
837 | } | |
838 | memset(passphrase, 0, strlen(passphrase)); | |
839 | xfree(passphrase); | |
840 | if (private != NULL || quit) | |
841 | break; | |
842 | debug2("bad passphrase given, try again..."); | |
843 | } | |
844 | } | |
845 | return private; | |
846 | } | |
847 | ||
848 | static int | |
1e608e42 | 849 | identity_sign_cb(Authctxt *authctxt, Key *key, u_char **sigp, u_int *lenp, |
850 | u_char *data, u_int datalen) | |
3c0ef626 | 851 | { |
852 | Key *private; | |
853 | int idx, ret; | |
854 | ||
855 | idx = authctxt->last_key_hint; | |
856 | if (idx < 0) | |
857 | return -1; | |
858 | ||
859 | /* private key is stored in external hardware */ | |
1e608e42 | 860 | if (options.identity_keys[idx]->flags & KEY_FLAG_EXT) |
3c0ef626 | 861 | return key_sign(options.identity_keys[idx], sigp, lenp, data, datalen); |
862 | ||
863 | private = load_identity_file(options.identity_files[idx]); | |
864 | if (private == NULL) | |
865 | return -1; | |
866 | ret = key_sign(private, sigp, lenp, data, datalen); | |
867 | key_free(private); | |
868 | return ret; | |
869 | } | |
870 | ||
871 | static int | |
1e608e42 | 872 | agent_sign_cb(Authctxt *authctxt, Key *key, u_char **sigp, u_int *lenp, |
873 | u_char *data, u_int datalen) | |
3c0ef626 | 874 | { |
875 | return ssh_agent_sign(authctxt->agent, key, sigp, lenp, data, datalen); | |
876 | } | |
877 | ||
878 | static int | |
1e608e42 | 879 | key_sign_cb(Authctxt *authctxt, Key *key, u_char **sigp, u_int *lenp, |
880 | u_char *data, u_int datalen) | |
3c0ef626 | 881 | { |
882 | return key_sign(key, sigp, lenp, data, datalen); | |
883 | } | |
884 | ||
885 | static int | |
886 | userauth_pubkey_agent(Authctxt *authctxt) | |
887 | { | |
888 | static int called = 0; | |
889 | int ret = 0; | |
890 | char *comment; | |
891 | Key *k; | |
892 | ||
893 | if (called == 0) { | |
894 | if (ssh_get_num_identities(authctxt->agent, 2) == 0) | |
895 | debug2("userauth_pubkey_agent: no keys at all"); | |
896 | called = 1; | |
897 | } | |
898 | k = ssh_get_next_identity(authctxt->agent, &comment, 2); | |
899 | if (k == NULL) { | |
900 | debug2("userauth_pubkey_agent: no more keys"); | |
901 | } else { | |
902 | debug("userauth_pubkey_agent: testing agent key %s", comment); | |
903 | xfree(comment); | |
904 | ret = send_pubkey_test(authctxt, k, agent_sign_cb, -1); | |
905 | if (ret == 0) | |
906 | key_free(k); | |
907 | } | |
908 | if (ret == 0) | |
909 | debug2("userauth_pubkey_agent: no message sent"); | |
910 | return ret; | |
911 | } | |
912 | ||
913 | int | |
914 | userauth_pubkey(Authctxt *authctxt) | |
915 | { | |
916 | static int idx = 0; | |
917 | int sent = 0; | |
918 | Key *key; | |
919 | char *filename; | |
920 | ||
921 | if (authctxt->agent != NULL) { | |
922 | do { | |
923 | sent = userauth_pubkey_agent(authctxt); | |
1e608e42 | 924 | } while (!sent && authctxt->agent->howmany > 0); |
3c0ef626 | 925 | } |
926 | while (!sent && idx < options.num_identity_files) { | |
927 | key = options.identity_keys[idx]; | |
928 | filename = options.identity_files[idx]; | |
929 | if (key == NULL) { | |
930 | debug("try privkey: %s", filename); | |
931 | key = load_identity_file(filename); | |
932 | if (key != NULL) { | |
933 | sent = sign_and_send_pubkey(authctxt, key, | |
934 | key_sign_cb); | |
935 | key_free(key); | |
936 | } | |
937 | } else if (key->type != KEY_RSA1) { | |
938 | debug("try pubkey: %s", filename); | |
939 | sent = send_pubkey_test(authctxt, key, | |
940 | identity_sign_cb, idx); | |
941 | } | |
942 | idx++; | |
943 | } | |
944 | return sent; | |
945 | } | |
946 | ||
947 | /* | |
948 | * Send userauth request message specifying keyboard-interactive method. | |
949 | */ | |
950 | int | |
951 | userauth_kbdint(Authctxt *authctxt) | |
952 | { | |
953 | static int attempt = 0; | |
954 | ||
955 | if (attempt++ >= options.number_of_password_prompts) | |
956 | return 0; | |
957 | /* disable if no SSH2_MSG_USERAUTH_INFO_REQUEST has been seen */ | |
958 | if (attempt > 1 && !authctxt->info_req_seen) { | |
959 | debug3("userauth_kbdint: disable: no info_req_seen"); | |
960 | dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, NULL); | |
961 | return 0; | |
962 | } | |
963 | ||
964 | debug2("userauth_kbdint"); | |
965 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
966 | packet_put_cstring(authctxt->server_user); | |
967 | packet_put_cstring(authctxt->service); | |
968 | packet_put_cstring(authctxt->method->name); | |
969 | packet_put_cstring(""); /* lang */ | |
970 | packet_put_cstring(options.kbd_interactive_devices ? | |
971 | options.kbd_interactive_devices : ""); | |
972 | packet_send(); | |
973 | ||
974 | dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, &input_userauth_info_req); | |
975 | return 1; | |
976 | } | |
977 | ||
978 | /* | |
979 | * parse INFO_REQUEST, prompt user and send INFO_RESPONSE | |
980 | */ | |
981 | void | |
1e608e42 | 982 | input_userauth_info_req(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 983 | { |
984 | Authctxt *authctxt = ctxt; | |
985 | char *name, *inst, *lang, *prompt, *response; | |
986 | u_int num_prompts, i; | |
987 | int echo = 0; | |
988 | ||
989 | debug2("input_userauth_info_req"); | |
990 | ||
991 | if (authctxt == NULL) | |
992 | fatal("input_userauth_info_req: no authentication context"); | |
993 | ||
994 | authctxt->info_req_seen = 1; | |
995 | ||
996 | name = packet_get_string(NULL); | |
997 | inst = packet_get_string(NULL); | |
998 | lang = packet_get_string(NULL); | |
999 | if (strlen(name) > 0) | |
1000 | log("%s", name); | |
1001 | if (strlen(inst) > 0) | |
1002 | log("%s", inst); | |
1003 | xfree(name); | |
1004 | xfree(inst); | |
1005 | xfree(lang); | |
1006 | ||
1007 | num_prompts = packet_get_int(); | |
1008 | /* | |
1009 | * Begin to build info response packet based on prompts requested. | |
1010 | * We commit to providing the correct number of responses, so if | |
1011 | * further on we run into a problem that prevents this, we have to | |
1012 | * be sure and clean this up and send a correct error response. | |
1013 | */ | |
1014 | packet_start(SSH2_MSG_USERAUTH_INFO_RESPONSE); | |
1015 | packet_put_int(num_prompts); | |
1016 | ||
1017 | debug2("input_userauth_info_req: num_prompts %d", num_prompts); | |
1018 | for (i = 0; i < num_prompts; i++) { | |
1019 | prompt = packet_get_string(NULL); | |
1020 | echo = packet_get_char(); | |
1021 | ||
1022 | response = read_passphrase(prompt, echo ? RP_ECHO : 0); | |
1023 | ||
1024 | packet_put_cstring(response); | |
1025 | memset(response, 0, strlen(response)); | |
1026 | xfree(response); | |
1027 | xfree(prompt); | |
1028 | } | |
1e608e42 | 1029 | packet_check_eom(); /* done with parsing incoming message. */ |
3c0ef626 | 1030 | |
1031 | packet_add_padding(64); | |
1032 | packet_send(); | |
1033 | } | |
1034 | ||
1035 | /* | |
1036 | * this will be move to an external program (ssh-keysign) ASAP. ssh-keysign | |
1037 | * will be setuid-root and the sbit can be removed from /usr/bin/ssh. | |
1038 | */ | |
1039 | int | |
1040 | userauth_hostbased(Authctxt *authctxt) | |
1041 | { | |
1042 | Key *private = NULL; | |
1043 | Buffer b; | |
1044 | u_char *signature, *blob; | |
1045 | char *chost, *pkalg, *p; | |
1046 | const char *service; | |
1047 | u_int blen, slen; | |
1048 | int ok, i, len, found = 0; | |
1049 | ||
1050 | /* check for a useful key */ | |
1051 | for (i = 0; i < authctxt->nkeys; i++) { | |
1052 | private = authctxt->keys[i]; | |
1053 | if (private && private->type != KEY_RSA1) { | |
1054 | found = 1; | |
1055 | /* we take and free the key */ | |
1056 | authctxt->keys[i] = NULL; | |
1057 | break; | |
1058 | } | |
1059 | } | |
1060 | if (!found) { | |
1061 | debug("userauth_hostbased: no more client hostkeys"); | |
1062 | return 0; | |
1063 | } | |
1064 | if (key_to_blob(private, &blob, &blen) == 0) { | |
1065 | key_free(private); | |
1066 | return 0; | |
1067 | } | |
1068 | /* figure out a name for the client host */ | |
1069 | p = get_local_name(packet_get_connection_in()); | |
1070 | if (p == NULL) { | |
1071 | error("userauth_hostbased: cannot get local ipaddr/name"); | |
1072 | key_free(private); | |
1073 | return 0; | |
1074 | } | |
1075 | len = strlen(p) + 2; | |
1076 | chost = xmalloc(len); | |
1077 | strlcpy(chost, p, len); | |
1078 | strlcat(chost, ".", len); | |
1079 | debug2("userauth_hostbased: chost %s", chost); | |
1080 | ||
1081 | service = datafellows & SSH_BUG_HBSERVICE ? "ssh-userauth" : | |
1082 | authctxt->service; | |
1083 | pkalg = xstrdup(key_ssh_name(private)); | |
1084 | buffer_init(&b); | |
1085 | /* construct data */ | |
1086 | buffer_put_string(&b, session_id2, session_id2_len); | |
1087 | buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST); | |
1088 | buffer_put_cstring(&b, authctxt->server_user); | |
1089 | buffer_put_cstring(&b, service); | |
1090 | buffer_put_cstring(&b, authctxt->method->name); | |
1091 | buffer_put_cstring(&b, pkalg); | |
1092 | buffer_put_string(&b, blob, blen); | |
1093 | buffer_put_cstring(&b, chost); | |
1094 | buffer_put_cstring(&b, authctxt->local_user); | |
1095 | #ifdef DEBUG_PK | |
1096 | buffer_dump(&b); | |
1097 | #endif | |
1098 | ok = key_sign(private, &signature, &slen, buffer_ptr(&b), buffer_len(&b)); | |
1099 | key_free(private); | |
1100 | buffer_free(&b); | |
1101 | if (ok != 0) { | |
1102 | error("key_sign failed"); | |
1103 | xfree(chost); | |
1104 | xfree(pkalg); | |
1105 | return 0; | |
1106 | } | |
1107 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
1108 | packet_put_cstring(authctxt->server_user); | |
1109 | packet_put_cstring(authctxt->service); | |
1110 | packet_put_cstring(authctxt->method->name); | |
1111 | packet_put_cstring(pkalg); | |
1112 | packet_put_string(blob, blen); | |
1113 | packet_put_cstring(chost); | |
1114 | packet_put_cstring(authctxt->local_user); | |
1115 | packet_put_string(signature, slen); | |
1116 | memset(signature, 's', slen); | |
1117 | xfree(signature); | |
1118 | xfree(chost); | |
1119 | xfree(pkalg); | |
1120 | ||
1121 | packet_send(); | |
1122 | return 1; | |
1123 | } | |
1124 | ||
1125 | /* find auth method */ | |
1126 | ||
1127 | /* | |
1128 | * given auth method name, if configurable options permit this method fill | |
1129 | * in auth_ident field and return true, otherwise return false. | |
1130 | */ | |
1131 | static int | |
1132 | authmethod_is_enabled(Authmethod *method) | |
1133 | { | |
1134 | if (method == NULL) | |
1135 | return 0; | |
1136 | /* return false if options indicate this method is disabled */ | |
1137 | if (method->enabled == NULL || *method->enabled == 0) | |
1138 | return 0; | |
1139 | /* return false if batch mode is enabled but method needs interactive mode */ | |
1140 | if (method->batch_flag != NULL && *method->batch_flag != 0) | |
1141 | return 0; | |
1142 | return 1; | |
1143 | } | |
1144 | ||
1145 | static Authmethod * | |
1146 | authmethod_lookup(const char *name) | |
1147 | { | |
1148 | Authmethod *method = NULL; | |
1149 | if (name != NULL) | |
1150 | for (method = authmethods; method->name != NULL; method++) | |
1151 | if (strcmp(name, method->name) == 0) | |
1152 | return method; | |
1153 | debug2("Unrecognized authentication method name: %s", name ? name : "NULL"); | |
1154 | return NULL; | |
1155 | } | |
1156 | ||
1157 | /* XXX internal state */ | |
1158 | static Authmethod *current = NULL; | |
1159 | static char *supported = NULL; | |
1160 | static char *preferred = NULL; | |
1161 | /* | |
1162 | * Given the authentication method list sent by the server, return the | |
1163 | * next method we should try. If the server initially sends a nil list, | |
1164 | * use a built-in default list. | |
1165 | */ | |
1166 | static Authmethod * | |
1167 | authmethod_get(char *authlist) | |
1168 | { | |
1169 | ||
1170 | char *name = NULL; | |
1e608e42 | 1171 | u_int next; |
3c0ef626 | 1172 | |
1173 | /* Use a suitable default if we're passed a nil list. */ | |
1174 | if (authlist == NULL || strlen(authlist) == 0) | |
1175 | authlist = options.preferred_authentications; | |
1176 | ||
1177 | if (supported == NULL || strcmp(authlist, supported) != 0) { | |
1178 | debug3("start over, passed a different list %s", authlist); | |
1179 | if (supported != NULL) | |
1180 | xfree(supported); | |
1181 | supported = xstrdup(authlist); | |
1182 | preferred = options.preferred_authentications; | |
1183 | debug3("preferred %s", preferred); | |
1184 | current = NULL; | |
1185 | } else if (current != NULL && authmethod_is_enabled(current)) | |
1186 | return current; | |
1187 | ||
1188 | for (;;) { | |
1189 | if ((name = match_list(preferred, supported, &next)) == NULL) { | |
1190 | debug("no more auth methods to try"); | |
1191 | current = NULL; | |
1192 | return NULL; | |
1193 | } | |
1194 | preferred += next; | |
1195 | debug3("authmethod_lookup %s", name); | |
1196 | debug3("remaining preferred: %s", preferred); | |
1197 | if ((current = authmethod_lookup(name)) != NULL && | |
1198 | authmethod_is_enabled(current)) { | |
1199 | debug3("authmethod_is_enabled %s", name); | |
1200 | debug("next auth method to try is %s", name); | |
1201 | return current; | |
1202 | } | |
1203 | } | |
1204 | } | |
1205 | ||
3c0ef626 | 1206 | static char * |
1207 | authmethods_get(void) | |
1208 | { | |
1209 | Authmethod *method = NULL; | |
1e608e42 | 1210 | Buffer b; |
1211 | char *list; | |
3c0ef626 | 1212 | |
1e608e42 | 1213 | buffer_init(&b); |
3c0ef626 | 1214 | for (method = authmethods; method->name != NULL; method++) { |
1215 | if (authmethod_is_enabled(method)) { | |
1e608e42 | 1216 | if (buffer_len(&b) > 0) |
1217 | buffer_append(&b, ",", 1); | |
1218 | buffer_append(&b, method->name, strlen(method->name)); | |
3c0ef626 | 1219 | } |
1220 | } | |
1e608e42 | 1221 | buffer_append(&b, "\0", 1); |
1222 | list = xstrdup(buffer_ptr(&b)); | |
1223 | buffer_free(&b); | |
1224 | return list; | |
3c0ef626 | 1225 | } |