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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" | |
2c06c99b | 26 | RCSID("$OpenBSD: sshconnect2.c,v 1.143 2005/10/14 02:17:59 stevesk Exp $"); |
0fff78ff | 27 | |
28 | #include "openbsd-compat/sys-queue.h" | |
3c0ef626 | 29 | |
30 | #include "ssh.h" | |
31 | #include "ssh2.h" | |
32 | #include "xmalloc.h" | |
3c0ef626 | 33 | #include "buffer.h" |
34 | #include "packet.h" | |
3c0ef626 | 35 | #include "compat.h" |
36 | #include "bufaux.h" | |
37 | #include "cipher.h" | |
38 | #include "kex.h" | |
39 | #include "myproposal.h" | |
3c0ef626 | 40 | #include "sshconnect.h" |
41 | #include "authfile.h" | |
42 | #include "dh.h" | |
43 | #include "authfd.h" | |
44 | #include "log.h" | |
45 | #include "readconf.h" | |
c9f39d2c | 46 | #include "misc.h" |
3c0ef626 | 47 | #include "match.h" |
48 | #include "dispatch.h" | |
49 | #include "canohost.h" | |
f5799ae1 | 50 | #include "msg.h" |
51 | #include "pathnames.h" | |
3c0ef626 | 52 | |
0fff78ff | 53 | #ifdef GSSAPI |
54 | #include "ssh-gss.h" | |
55 | #endif | |
56 | ||
3c0ef626 | 57 | /* import */ |
58 | extern char *client_version_string; | |
59 | extern char *server_version_string; | |
60 | extern Options options; | |
e90c2d47 | 61 | extern Kex *xxx_kex; |
62 | ||
63 | /* tty_flag is set in ssh.c. use this in ssh_userauth2 */ | |
64 | /* if it is set then prevent the switch to the null cipher */ | |
65 | ||
66 | extern int tty_flag; | |
3c0ef626 | 67 | |
68 | /* | |
69 | * SSH2 key exchange | |
70 | */ | |
71 | ||
72 | u_char *session_id2 = NULL; | |
0fff78ff | 73 | u_int session_id2_len = 0; |
3c0ef626 | 74 | |
75 | char *xxx_host; | |
76 | struct sockaddr *xxx_hostaddr; | |
77 | ||
78 | Kex *xxx_kex = NULL; | |
79 | ||
80 | static int | |
81 | verify_host_key_callback(Key *hostkey) | |
82 | { | |
83 | if (verify_host_key(xxx_host, xxx_hostaddr, hostkey) == -1) | |
84 | fatal("Host key verification failed."); | |
85 | return 0; | |
86 | } | |
87 | ||
88 | void | |
89 | ssh_kex2(char *host, struct sockaddr *hostaddr) | |
90 | { | |
91 | Kex *kex; | |
92 | ||
93 | xxx_host = host; | |
94 | xxx_hostaddr = hostaddr; | |
95 | ||
96 | if (options.ciphers == (char *)-1) { | |
0fff78ff | 97 | logit("No valid ciphers for protocol version 2 given, using defaults."); |
3c0ef626 | 98 | options.ciphers = NULL; |
99 | } | |
100 | if (options.ciphers != NULL) { | |
101 | myproposal[PROPOSAL_ENC_ALGS_CTOS] = | |
102 | myproposal[PROPOSAL_ENC_ALGS_STOC] = options.ciphers; | |
103 | } | |
104 | myproposal[PROPOSAL_ENC_ALGS_CTOS] = | |
105 | compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_CTOS]); | |
106 | myproposal[PROPOSAL_ENC_ALGS_STOC] = | |
107 | compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_STOC]); | |
108 | if (options.compression) { | |
109 | myproposal[PROPOSAL_COMP_ALGS_CTOS] = | |
665a873d | 110 | myproposal[PROPOSAL_COMP_ALGS_STOC] = "zlib@openssh.com,zlib,none"; |
3c0ef626 | 111 | } else { |
112 | myproposal[PROPOSAL_COMP_ALGS_CTOS] = | |
665a873d | 113 | myproposal[PROPOSAL_COMP_ALGS_STOC] = "none,zlib@openssh.com,zlib"; |
3c0ef626 | 114 | } |
115 | if (options.macs != NULL) { | |
116 | myproposal[PROPOSAL_MAC_ALGS_CTOS] = | |
117 | myproposal[PROPOSAL_MAC_ALGS_STOC] = options.macs; | |
118 | } | |
119 | if (options.hostkeyalgorithms != NULL) | |
e9a17296 | 120 | myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = |
3c0ef626 | 121 | options.hostkeyalgorithms; |
122 | ||
0fff78ff | 123 | if (options.rekey_limit) |
124 | packet_set_rekey_limit(options.rekey_limit); | |
125 | ||
3c0ef626 | 126 | /* start key exchange */ |
127 | kex = kex_setup(myproposal); | |
6a9b3198 | 128 | kex->kex[KEX_DH_GRP1_SHA1] = kexdh_client; |
c9f39d2c | 129 | kex->kex[KEX_DH_GRP14_SHA1] = kexdh_client; |
6a9b3198 | 130 | kex->kex[KEX_DH_GEX_SHA1] = kexgex_client; |
3c0ef626 | 131 | kex->client_version_string=client_version_string; |
132 | kex->server_version_string=server_version_string; | |
133 | kex->verify_host_key=&verify_host_key_callback; | |
134 | ||
135 | xxx_kex = kex; | |
136 | ||
137 | dispatch_run(DISPATCH_BLOCK, &kex->done, kex); | |
138 | ||
139 | session_id2 = kex->session_id; | |
140 | session_id2_len = kex->session_id_len; | |
141 | ||
142 | #ifdef DEBUG_KEXDH | |
143 | /* send 1st encrypted/maced/compressed message */ | |
144 | packet_start(SSH2_MSG_IGNORE); | |
145 | packet_put_cstring("markus"); | |
146 | packet_send(); | |
147 | packet_write_wait(); | |
148 | #endif | |
3c0ef626 | 149 | } |
150 | ||
151 | /* | |
152 | * Authenticate user | |
153 | */ | |
154 | ||
155 | typedef struct Authctxt Authctxt; | |
156 | typedef struct Authmethod Authmethod; | |
0fff78ff | 157 | typedef struct identity Identity; |
158 | typedef struct idlist Idlist; | |
159 | ||
160 | struct identity { | |
161 | TAILQ_ENTRY(identity) next; | |
162 | AuthenticationConnection *ac; /* set if agent supports key */ | |
163 | Key *key; /* public/private key */ | |
164 | char *filename; /* comment for agent-only keys */ | |
165 | int tried; | |
166 | int isprivate; /* key points to the private key */ | |
167 | }; | |
168 | TAILQ_HEAD(idlist, identity); | |
3c0ef626 | 169 | |
170 | struct Authctxt { | |
171 | const char *server_user; | |
172 | const char *local_user; | |
173 | const char *host; | |
174 | const char *service; | |
175 | Authmethod *method; | |
176 | int success; | |
177 | char *authlist; | |
178 | /* pubkey */ | |
0fff78ff | 179 | Idlist keys; |
3c0ef626 | 180 | AuthenticationConnection *agent; |
181 | /* hostbased */ | |
f5799ae1 | 182 | Sensitive *sensitive; |
3c0ef626 | 183 | /* kbd-interactive */ |
184 | int info_req_seen; | |
0fff78ff | 185 | /* generic */ |
186 | void *methoddata; | |
3c0ef626 | 187 | }; |
188 | struct Authmethod { | |
189 | char *name; /* string to compare against server's list */ | |
190 | int (*userauth)(Authctxt *authctxt); | |
191 | int *enabled; /* flag in option struct that enables method */ | |
192 | int *batch_flag; /* flag in option struct that disables method */ | |
193 | }; | |
194 | ||
e9a17296 | 195 | void input_userauth_success(int, u_int32_t, void *); |
196 | void input_userauth_failure(int, u_int32_t, void *); | |
197 | void input_userauth_banner(int, u_int32_t, void *); | |
198 | void input_userauth_error(int, u_int32_t, void *); | |
199 | void input_userauth_info_req(int, u_int32_t, void *); | |
200 | void input_userauth_pk_ok(int, u_int32_t, void *); | |
700318f3 | 201 | void input_userauth_passwd_changereq(int, u_int32_t, void *); |
3c0ef626 | 202 | |
e9a17296 | 203 | int userauth_none(Authctxt *); |
204 | int userauth_pubkey(Authctxt *); | |
205 | int userauth_passwd(Authctxt *); | |
206 | int userauth_kbdint(Authctxt *); | |
207 | int userauth_hostbased(Authctxt *); | |
0fff78ff | 208 | int userauth_kerberos(Authctxt *); |
209 | ||
210 | #ifdef GSSAPI | |
211 | int userauth_gssapi(Authctxt *authctxt); | |
212 | void input_gssapi_response(int type, u_int32_t, void *); | |
213 | void input_gssapi_token(int type, u_int32_t, void *); | |
214 | void input_gssapi_hash(int type, u_int32_t, void *); | |
215 | void input_gssapi_error(int, u_int32_t, void *); | |
216 | void input_gssapi_errtok(int, u_int32_t, void *); | |
217 | #endif | |
3c0ef626 | 218 | |
e9a17296 | 219 | void userauth(Authctxt *, char *); |
3c0ef626 | 220 | |
0fff78ff | 221 | static int sign_and_send_pubkey(Authctxt *, Identity *); |
222 | static void pubkey_prepare(Authctxt *); | |
223 | static void pubkey_cleanup(Authctxt *); | |
224 | static Key *load_identity_file(char *); | |
3c0ef626 | 225 | |
226 | static Authmethod *authmethod_get(char *authlist); | |
227 | static Authmethod *authmethod_lookup(const char *name); | |
228 | static char *authmethods_get(void); | |
229 | ||
230 | Authmethod authmethods[] = { | |
0fff78ff | 231 | #ifdef GSSAPI |
cdd66111 | 232 | {"gssapi-with-mic", |
0fff78ff | 233 | userauth_gssapi, |
234 | &options.gss_authentication, | |
235 | NULL}, | |
236 | #endif | |
3c0ef626 | 237 | {"hostbased", |
238 | userauth_hostbased, | |
239 | &options.hostbased_authentication, | |
240 | NULL}, | |
241 | {"publickey", | |
242 | userauth_pubkey, | |
243 | &options.pubkey_authentication, | |
244 | NULL}, | |
245 | {"keyboard-interactive", | |
246 | userauth_kbdint, | |
247 | &options.kbd_interactive_authentication, | |
248 | &options.batch_mode}, | |
249 | {"password", | |
250 | userauth_passwd, | |
251 | &options.password_authentication, | |
252 | &options.batch_mode}, | |
253 | {"none", | |
254 | userauth_none, | |
255 | NULL, | |
256 | NULL}, | |
257 | {NULL, NULL, NULL, NULL} | |
258 | }; | |
259 | ||
260 | void | |
261 | ssh_userauth2(const char *local_user, const char *server_user, char *host, | |
f5799ae1 | 262 | Sensitive *sensitive) |
3c0ef626 | 263 | { |
264 | Authctxt authctxt; | |
265 | int type; | |
3c0ef626 | 266 | |
267 | if (options.challenge_response_authentication) | |
268 | options.kbd_interactive_authentication = 1; | |
269 | ||
3c0ef626 | 270 | packet_start(SSH2_MSG_SERVICE_REQUEST); |
271 | packet_put_cstring("ssh-userauth"); | |
272 | packet_send(); | |
6a9b3198 | 273 | debug("SSH2_MSG_SERVICE_REQUEST sent"); |
3c0ef626 | 274 | packet_write_wait(); |
e9a17296 | 275 | type = packet_read(); |
6a9b3198 | 276 | if (type != SSH2_MSG_SERVICE_ACCEPT) |
277 | fatal("Server denied authentication request: %d", type); | |
3c0ef626 | 278 | if (packet_remaining() > 0) { |
e9a17296 | 279 | char *reply = packet_get_string(NULL); |
6a9b3198 | 280 | debug2("service_accept: %s", reply); |
3c0ef626 | 281 | xfree(reply); |
282 | } else { | |
6a9b3198 | 283 | debug2("buggy server: service_accept w/o service"); |
3c0ef626 | 284 | } |
e9a17296 | 285 | packet_check_eom(); |
6a9b3198 | 286 | debug("SSH2_MSG_SERVICE_ACCEPT received"); |
3c0ef626 | 287 | |
288 | if (options.preferred_authentications == NULL) | |
289 | options.preferred_authentications = authmethods_get(); | |
290 | ||
291 | /* setup authentication context */ | |
292 | memset(&authctxt, 0, sizeof(authctxt)); | |
0fff78ff | 293 | pubkey_prepare(&authctxt); |
3c0ef626 | 294 | authctxt.server_user = server_user; |
295 | authctxt.local_user = local_user; | |
296 | authctxt.host = host; | |
297 | authctxt.service = "ssh-connection"; /* service name */ | |
298 | authctxt.success = 0; | |
299 | authctxt.method = authmethod_lookup("none"); | |
300 | authctxt.authlist = NULL; | |
0fff78ff | 301 | authctxt.methoddata = NULL; |
f5799ae1 | 302 | authctxt.sensitive = sensitive; |
3c0ef626 | 303 | authctxt.info_req_seen = 0; |
304 | if (authctxt.method == NULL) | |
305 | fatal("ssh_userauth2: internal error: cannot send userauth none request"); | |
306 | ||
307 | /* initial userauth request */ | |
308 | userauth_none(&authctxt); | |
309 | ||
310 | dispatch_init(&input_userauth_error); | |
311 | dispatch_set(SSH2_MSG_USERAUTH_SUCCESS, &input_userauth_success); | |
312 | dispatch_set(SSH2_MSG_USERAUTH_FAILURE, &input_userauth_failure); | |
313 | dispatch_set(SSH2_MSG_USERAUTH_BANNER, &input_userauth_banner); | |
314 | dispatch_run(DISPATCH_BLOCK, &authctxt.success, &authctxt); /* loop until success */ | |
315 | ||
0fff78ff | 316 | pubkey_cleanup(&authctxt); |
317 | dispatch_range(SSH2_MSG_USERAUTH_MIN, SSH2_MSG_USERAUTH_MAX, NULL); | |
e90c2d47 | 318 | if ((options.none_switch == 1) && !tty_flag) /* no null on tty sessions */ |
319 | { | |
320 | debug("Requesting none rekeying..."); | |
321 | myproposal[PROPOSAL_ENC_ALGS_STOC] = "none"; | |
322 | myproposal[PROPOSAL_ENC_ALGS_CTOS] = "none"; | |
323 | kex_prop2buf(&xxx_kex->my,myproposal); | |
324 | packet_request_rekeying(); | |
325 | fprintf(stderr, "WARNING: ENABLED NULL CIPHER\n"); | |
326 | } | |
6a9b3198 | 327 | debug("Authentication succeeded (%s).", authctxt.method->name); |
3c0ef626 | 328 | } |
0fff78ff | 329 | |
3c0ef626 | 330 | void |
331 | userauth(Authctxt *authctxt, char *authlist) | |
332 | { | |
0fff78ff | 333 | if (authctxt->methoddata) { |
334 | xfree(authctxt->methoddata); | |
335 | authctxt->methoddata = NULL; | |
336 | } | |
3c0ef626 | 337 | if (authlist == NULL) { |
338 | authlist = authctxt->authlist; | |
339 | } else { | |
340 | if (authctxt->authlist) | |
341 | xfree(authctxt->authlist); | |
342 | authctxt->authlist = authlist; | |
343 | } | |
344 | for (;;) { | |
345 | Authmethod *method = authmethod_get(authlist); | |
346 | if (method == NULL) | |
347 | fatal("Permission denied (%s).", authlist); | |
348 | authctxt->method = method; | |
0fff78ff | 349 | |
350 | /* reset the per method handler */ | |
351 | dispatch_range(SSH2_MSG_USERAUTH_PER_METHOD_MIN, | |
352 | SSH2_MSG_USERAUTH_PER_METHOD_MAX, NULL); | |
353 | ||
354 | /* and try new method */ | |
3c0ef626 | 355 | if (method->userauth(authctxt) != 0) { |
356 | debug2("we sent a %s packet, wait for reply", method->name); | |
357 | break; | |
358 | } else { | |
359 | debug2("we did not send a packet, disable method"); | |
360 | method->enabled = NULL; | |
361 | } | |
362 | } | |
363 | } | |
680cee3b | 364 | |
3c0ef626 | 365 | void |
e9a17296 | 366 | input_userauth_error(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 367 | { |
368 | fatal("input_userauth_error: bad message during authentication: " | |
665a873d | 369 | "type %d", type); |
3c0ef626 | 370 | } |
680cee3b | 371 | |
3c0ef626 | 372 | void |
e9a17296 | 373 | input_userauth_banner(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 374 | { |
375 | char *msg, *lang; | |
cdd66111 | 376 | |
3c0ef626 | 377 | debug3("input_userauth_banner"); |
378 | msg = packet_get_string(NULL); | |
379 | lang = packet_get_string(NULL); | |
cdd66111 | 380 | if (options.log_level > SYSLOG_LEVEL_QUIET) |
381 | fprintf(stderr, "%s", msg); | |
3c0ef626 | 382 | xfree(msg); |
383 | xfree(lang); | |
384 | } | |
680cee3b | 385 | |
3c0ef626 | 386 | void |
e9a17296 | 387 | input_userauth_success(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 388 | { |
389 | Authctxt *authctxt = ctxt; | |
390 | if (authctxt == NULL) | |
391 | fatal("input_userauth_success: no authentication context"); | |
cdd66111 | 392 | if (authctxt->authlist) { |
3c0ef626 | 393 | xfree(authctxt->authlist); |
cdd66111 | 394 | authctxt->authlist = NULL; |
395 | } | |
396 | if (authctxt->methoddata) { | |
0fff78ff | 397 | xfree(authctxt->methoddata); |
cdd66111 | 398 | authctxt->methoddata = NULL; |
399 | } | |
3c0ef626 | 400 | authctxt->success = 1; /* break out */ |
401 | } | |
680cee3b | 402 | |
3c0ef626 | 403 | void |
e9a17296 | 404 | input_userauth_failure(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 405 | { |
406 | Authctxt *authctxt = ctxt; | |
407 | char *authlist = NULL; | |
408 | int partial; | |
409 | ||
410 | if (authctxt == NULL) | |
411 | fatal("input_userauth_failure: no authentication context"); | |
412 | ||
413 | authlist = packet_get_string(NULL); | |
414 | partial = packet_get_char(); | |
e9a17296 | 415 | packet_check_eom(); |
3c0ef626 | 416 | |
417 | if (partial != 0) | |
0fff78ff | 418 | logit("Authenticated with partial success."); |
6a9b3198 | 419 | debug("Authentications that can continue: %s", authlist); |
3c0ef626 | 420 | |
3c0ef626 | 421 | userauth(authctxt, authlist); |
422 | } | |
423 | void | |
e9a17296 | 424 | input_userauth_pk_ok(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 425 | { |
426 | Authctxt *authctxt = ctxt; | |
427 | Key *key = NULL; | |
0fff78ff | 428 | Identity *id = NULL; |
3c0ef626 | 429 | Buffer b; |
e9a17296 | 430 | int pktype, sent = 0; |
431 | u_int alen, blen; | |
432 | char *pkalg, *fp; | |
433 | u_char *pkblob; | |
3c0ef626 | 434 | |
435 | if (authctxt == NULL) | |
436 | fatal("input_userauth_pk_ok: no authentication context"); | |
437 | if (datafellows & SSH_BUG_PKOK) { | |
438 | /* this is similar to SSH_BUG_PKAUTH */ | |
439 | debug2("input_userauth_pk_ok: SSH_BUG_PKOK"); | |
440 | pkblob = packet_get_string(&blen); | |
441 | buffer_init(&b); | |
442 | buffer_append(&b, pkblob, blen); | |
443 | pkalg = buffer_get_string(&b, &alen); | |
444 | buffer_free(&b); | |
445 | } else { | |
446 | pkalg = packet_get_string(&alen); | |
447 | pkblob = packet_get_string(&blen); | |
448 | } | |
e9a17296 | 449 | packet_check_eom(); |
3c0ef626 | 450 | |
0fff78ff | 451 | debug("Server accepts key: pkalg %s blen %u", pkalg, blen); |
3c0ef626 | 452 | |
0fff78ff | 453 | if ((pktype = key_type_from_name(pkalg)) == KEY_UNSPEC) { |
454 | debug("unknown pkalg %s", pkalg); | |
455 | goto done; | |
456 | } | |
457 | if ((key = key_from_blob(pkblob, blen)) == NULL) { | |
458 | debug("no key from blob. pkalg %s", pkalg); | |
459 | goto done; | |
460 | } | |
461 | if (key->type != pktype) { | |
462 | error("input_userauth_pk_ok: type mismatch " | |
463 | "for decoded key (received %d, expected %d)", | |
464 | key->type, pktype); | |
465 | goto done; | |
466 | } | |
467 | fp = key_fingerprint(key, SSH_FP_MD5, SSH_FP_HEX); | |
468 | debug2("input_userauth_pk_ok: fp %s", fp); | |
469 | xfree(fp); | |
470 | ||
cdd66111 | 471 | /* |
472 | * search keys in the reverse order, because last candidate has been | |
473 | * moved to the end of the queue. this also avoids confusion by | |
474 | * duplicate keys | |
475 | */ | |
c9f39d2c | 476 | TAILQ_FOREACH_REVERSE(id, &authctxt->keys, idlist, next) { |
0fff78ff | 477 | if (key_equal(key, id->key)) { |
478 | sent = sign_and_send_pubkey(authctxt, id); | |
3c0ef626 | 479 | break; |
480 | } | |
0fff78ff | 481 | } |
482 | done: | |
3c0ef626 | 483 | if (key != NULL) |
484 | key_free(key); | |
485 | xfree(pkalg); | |
486 | xfree(pkblob); | |
487 | ||
41b2f314 | 488 | /* try another method if we did not send a packet */ |
3c0ef626 | 489 | if (sent == 0) |
490 | userauth(authctxt, NULL); | |
0fff78ff | 491 | } |
492 | ||
493 | #ifdef GSSAPI | |
cdd66111 | 494 | int |
0fff78ff | 495 | userauth_gssapi(Authctxt *authctxt) |
496 | { | |
497 | Gssctxt *gssctxt = NULL; | |
cdd66111 | 498 | static gss_OID_set gss_supported = NULL; |
665a873d | 499 | static u_int mech = 0; |
0fff78ff | 500 | OM_uint32 min; |
501 | int ok = 0; | |
502 | ||
503 | /* Try one GSSAPI method at a time, rather than sending them all at | |
504 | * once. */ | |
505 | ||
cdd66111 | 506 | if (gss_supported == NULL) |
507 | gss_indicate_mechs(&min, &gss_supported); | |
0fff78ff | 508 | |
509 | /* Check to see if the mechanism is usable before we offer it */ | |
cdd66111 | 510 | while (mech < gss_supported->count && !ok) { |
0fff78ff | 511 | if (gssctxt) |
512 | ssh_gssapi_delete_ctx(&gssctxt); | |
513 | ssh_gssapi_build_ctx(&gssctxt); | |
cdd66111 | 514 | ssh_gssapi_set_oid(gssctxt, &gss_supported->elements[mech]); |
0fff78ff | 515 | |
516 | /* My DER encoding requires length<128 */ | |
cdd66111 | 517 | if (gss_supported->elements[mech].length < 128 && |
0fff78ff | 518 | !GSS_ERROR(ssh_gssapi_import_name(gssctxt, |
519 | authctxt->host))) { | |
520 | ok = 1; /* Mechanism works */ | |
521 | } else { | |
522 | mech++; | |
523 | } | |
524 | } | |
525 | ||
665a873d | 526 | if (!ok) |
527 | return 0; | |
0fff78ff | 528 | |
529 | authctxt->methoddata=(void *)gssctxt; | |
530 | ||
531 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
532 | packet_put_cstring(authctxt->server_user); | |
533 | packet_put_cstring(authctxt->service); | |
534 | packet_put_cstring(authctxt->method->name); | |
535 | ||
536 | packet_put_int(1); | |
537 | ||
cdd66111 | 538 | packet_put_int((gss_supported->elements[mech].length) + 2); |
539 | packet_put_char(SSH_GSS_OIDTYPE); | |
540 | packet_put_char(gss_supported->elements[mech].length); | |
541 | packet_put_raw(gss_supported->elements[mech].elements, | |
542 | gss_supported->elements[mech].length); | |
0fff78ff | 543 | |
544 | packet_send(); | |
545 | ||
546 | dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE, &input_gssapi_response); | |
547 | dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, &input_gssapi_token); | |
548 | dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERROR, &input_gssapi_error); | |
549 | dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, &input_gssapi_errtok); | |
550 | ||
551 | mech++; /* Move along to next candidate */ | |
552 | ||
553 | return 1; | |
554 | } | |
555 | ||
cdd66111 | 556 | static OM_uint32 |
557 | process_gssapi_token(void *ctxt, gss_buffer_t recv_tok) | |
558 | { | |
559 | Authctxt *authctxt = ctxt; | |
560 | Gssctxt *gssctxt = authctxt->methoddata; | |
561 | gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER; | |
665a873d | 562 | gss_buffer_desc mic = GSS_C_EMPTY_BUFFER; |
563 | gss_buffer_desc gssbuf; | |
cdd66111 | 564 | OM_uint32 status, ms, flags; |
565 | Buffer b; | |
566 | ||
567 | status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds, | |
568 | recv_tok, &send_tok, &flags); | |
569 | ||
570 | if (send_tok.length > 0) { | |
571 | if (GSS_ERROR(status)) | |
572 | packet_start(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK); | |
573 | else | |
574 | packet_start(SSH2_MSG_USERAUTH_GSSAPI_TOKEN); | |
575 | ||
576 | packet_put_string(send_tok.value, send_tok.length); | |
577 | packet_send(); | |
578 | gss_release_buffer(&ms, &send_tok); | |
579 | } | |
580 | ||
581 | if (status == GSS_S_COMPLETE) { | |
582 | /* send either complete or MIC, depending on mechanism */ | |
583 | if (!(flags & GSS_C_INTEG_FLAG)) { | |
584 | packet_start(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE); | |
585 | packet_send(); | |
586 | } else { | |
587 | ssh_gssapi_buildmic(&b, authctxt->server_user, | |
588 | authctxt->service, "gssapi-with-mic"); | |
589 | ||
590 | gssbuf.value = buffer_ptr(&b); | |
591 | gssbuf.length = buffer_len(&b); | |
592 | ||
593 | status = ssh_gssapi_sign(gssctxt, &gssbuf, &mic); | |
594 | ||
595 | if (!GSS_ERROR(status)) { | |
596 | packet_start(SSH2_MSG_USERAUTH_GSSAPI_MIC); | |
597 | packet_put_string(mic.value, mic.length); | |
598 | ||
599 | packet_send(); | |
600 | } | |
601 | ||
602 | buffer_free(&b); | |
603 | gss_release_buffer(&ms, &mic); | |
604 | } | |
605 | } | |
606 | ||
607 | return status; | |
608 | } | |
609 | ||
0fff78ff | 610 | void |
611 | input_gssapi_response(int type, u_int32_t plen, void *ctxt) | |
612 | { | |
613 | Authctxt *authctxt = ctxt; | |
614 | Gssctxt *gssctxt; | |
0fff78ff | 615 | int oidlen; |
616 | char *oidv; | |
0fff78ff | 617 | |
618 | if (authctxt == NULL) | |
619 | fatal("input_gssapi_response: no authentication context"); | |
620 | gssctxt = authctxt->methoddata; | |
621 | ||
622 | /* Setup our OID */ | |
623 | oidv = packet_get_string(&oidlen); | |
624 | ||
cdd66111 | 625 | if (oidlen <= 2 || |
626 | oidv[0] != SSH_GSS_OIDTYPE || | |
627 | oidv[1] != oidlen - 2) { | |
628 | xfree(oidv); | |
629 | debug("Badly encoded mechanism OID received"); | |
630 | userauth(authctxt, NULL); | |
631 | return; | |
0fff78ff | 632 | } |
633 | ||
cdd66111 | 634 | if (!ssh_gssapi_check_oid(gssctxt, oidv + 2, oidlen - 2)) |
635 | fatal("Server returned different OID than expected"); | |
636 | ||
0fff78ff | 637 | packet_check_eom(); |
638 | ||
639 | xfree(oidv); | |
640 | ||
cdd66111 | 641 | if (GSS_ERROR(process_gssapi_token(ctxt, GSS_C_NO_BUFFER))) { |
0fff78ff | 642 | /* Start again with next method on list */ |
643 | debug("Trying to start again"); | |
644 | userauth(authctxt, NULL); | |
645 | return; | |
646 | } | |
0fff78ff | 647 | } |
648 | ||
649 | void | |
650 | input_gssapi_token(int type, u_int32_t plen, void *ctxt) | |
651 | { | |
652 | Authctxt *authctxt = ctxt; | |
0fff78ff | 653 | gss_buffer_desc recv_tok; |
cdd66111 | 654 | OM_uint32 status; |
0fff78ff | 655 | u_int slen; |
656 | ||
657 | if (authctxt == NULL) | |
658 | fatal("input_gssapi_response: no authentication context"); | |
0fff78ff | 659 | |
660 | recv_tok.value = packet_get_string(&slen); | |
661 | recv_tok.length = slen; /* safe typecast */ | |
662 | ||
663 | packet_check_eom(); | |
664 | ||
cdd66111 | 665 | status = process_gssapi_token(ctxt, &recv_tok); |
0fff78ff | 666 | |
667 | xfree(recv_tok.value); | |
668 | ||
669 | if (GSS_ERROR(status)) { | |
0fff78ff | 670 | /* Start again with the next method in the list */ |
671 | userauth(authctxt, NULL); | |
672 | return; | |
673 | } | |
3c0ef626 | 674 | } |
675 | ||
0fff78ff | 676 | void |
677 | input_gssapi_errtok(int type, u_int32_t plen, void *ctxt) | |
678 | { | |
679 | Authctxt *authctxt = ctxt; | |
680 | Gssctxt *gssctxt; | |
681 | gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER; | |
682 | gss_buffer_desc recv_tok; | |
683 | OM_uint32 status, ms; | |
684 | u_int len; | |
685 | ||
686 | if (authctxt == NULL) | |
687 | fatal("input_gssapi_response: no authentication context"); | |
688 | gssctxt = authctxt->methoddata; | |
689 | ||
690 | recv_tok.value = packet_get_string(&len); | |
691 | recv_tok.length = len; | |
692 | ||
693 | packet_check_eom(); | |
694 | ||
695 | /* Stick it into GSSAPI and see what it says */ | |
696 | status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds, | |
665a873d | 697 | &recv_tok, &send_tok, NULL); |
0fff78ff | 698 | |
699 | xfree(recv_tok.value); | |
700 | gss_release_buffer(&ms, &send_tok); | |
701 | ||
702 | /* Server will be returning a failed packet after this one */ | |
703 | } | |
704 | ||
705 | void | |
706 | input_gssapi_error(int type, u_int32_t plen, void *ctxt) | |
707 | { | |
708 | OM_uint32 maj, min; | |
709 | char *msg; | |
710 | char *lang; | |
711 | ||
712 | maj=packet_get_int(); | |
713 | min=packet_get_int(); | |
714 | msg=packet_get_string(NULL); | |
715 | lang=packet_get_string(NULL); | |
716 | ||
717 | packet_check_eom(); | |
718 | ||
2c06c99b | 719 | debug("Server GSSAPI Error:\n%s", msg); |
0fff78ff | 720 | xfree(msg); |
721 | xfree(lang); | |
722 | } | |
723 | #endif /* GSSAPI */ | |
724 | ||
3c0ef626 | 725 | int |
726 | userauth_none(Authctxt *authctxt) | |
727 | { | |
728 | /* initial userauth request */ | |
729 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
730 | packet_put_cstring(authctxt->server_user); | |
731 | packet_put_cstring(authctxt->service); | |
732 | packet_put_cstring(authctxt->method->name); | |
733 | packet_send(); | |
734 | return 1; | |
735 | } | |
736 | ||
737 | int | |
738 | userauth_passwd(Authctxt *authctxt) | |
739 | { | |
740 | static int attempt = 0; | |
700318f3 | 741 | char prompt[150]; |
3c0ef626 | 742 | char *password; |
743 | ||
744 | if (attempt++ >= options.number_of_password_prompts) | |
745 | return 0; | |
746 | ||
e9a17296 | 747 | if (attempt != 1) |
3c0ef626 | 748 | error("Permission denied, please try again."); |
749 | ||
750 | snprintf(prompt, sizeof(prompt), "%.30s@%.128s's password: ", | |
751 | authctxt->server_user, authctxt->host); | |
752 | password = read_passphrase(prompt, 0); | |
753 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
754 | packet_put_cstring(authctxt->server_user); | |
755 | packet_put_cstring(authctxt->service); | |
756 | packet_put_cstring(authctxt->method->name); | |
757 | packet_put_char(0); | |
758 | packet_put_cstring(password); | |
759 | memset(password, 0, strlen(password)); | |
760 | xfree(password); | |
761 | packet_add_padding(64); | |
762 | packet_send(); | |
700318f3 | 763 | |
f5799ae1 | 764 | dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, |
700318f3 | 765 | &input_userauth_passwd_changereq); |
766 | ||
3c0ef626 | 767 | return 1; |
768 | } | |
700318f3 | 769 | /* |
770 | * parse PASSWD_CHANGEREQ, prompt user and send SSH2_MSG_USERAUTH_REQUEST | |
771 | */ | |
772 | void | |
773 | input_userauth_passwd_changereq(int type, u_int32_t seqnr, void *ctxt) | |
774 | { | |
775 | Authctxt *authctxt = ctxt; | |
776 | char *info, *lang, *password = NULL, *retype = NULL; | |
777 | char prompt[150]; | |
778 | ||
779 | debug2("input_userauth_passwd_changereq"); | |
780 | ||
781 | if (authctxt == NULL) | |
782 | fatal("input_userauth_passwd_changereq: " | |
783 | "no authentication context"); | |
784 | ||
785 | info = packet_get_string(NULL); | |
786 | lang = packet_get_string(NULL); | |
787 | if (strlen(info) > 0) | |
0fff78ff | 788 | logit("%s", info); |
700318f3 | 789 | xfree(info); |
790 | xfree(lang); | |
791 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
792 | packet_put_cstring(authctxt->server_user); | |
793 | packet_put_cstring(authctxt->service); | |
794 | packet_put_cstring(authctxt->method->name); | |
795 | packet_put_char(1); /* additional info */ | |
f5799ae1 | 796 | snprintf(prompt, sizeof(prompt), |
700318f3 | 797 | "Enter %.30s@%.128s's old password: ", |
798 | authctxt->server_user, authctxt->host); | |
799 | password = read_passphrase(prompt, 0); | |
800 | packet_put_cstring(password); | |
801 | memset(password, 0, strlen(password)); | |
802 | xfree(password); | |
803 | password = NULL; | |
804 | while (password == NULL) { | |
f5799ae1 | 805 | snprintf(prompt, sizeof(prompt), |
700318f3 | 806 | "Enter %.30s@%.128s's new password: ", |
807 | authctxt->server_user, authctxt->host); | |
808 | password = read_passphrase(prompt, RP_ALLOW_EOF); | |
809 | if (password == NULL) { | |
810 | /* bail out */ | |
811 | return; | |
812 | } | |
f5799ae1 | 813 | snprintf(prompt, sizeof(prompt), |
700318f3 | 814 | "Retype %.30s@%.128s's new password: ", |
815 | authctxt->server_user, authctxt->host); | |
816 | retype = read_passphrase(prompt, 0); | |
817 | if (strcmp(password, retype) != 0) { | |
818 | memset(password, 0, strlen(password)); | |
819 | xfree(password); | |
0fff78ff | 820 | logit("Mismatch; try again, EOF to quit."); |
700318f3 | 821 | password = NULL; |
822 | } | |
823 | memset(retype, 0, strlen(retype)); | |
824 | xfree(retype); | |
825 | } | |
826 | packet_put_cstring(password); | |
827 | memset(password, 0, strlen(password)); | |
828 | xfree(password); | |
829 | packet_add_padding(64); | |
830 | packet_send(); | |
f5799ae1 | 831 | |
832 | dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, | |
700318f3 | 833 | &input_userauth_passwd_changereq); |
834 | } | |
3c0ef626 | 835 | |
0fff78ff | 836 | static int |
837 | identity_sign(Identity *id, u_char **sigp, u_int *lenp, | |
838 | u_char *data, u_int datalen) | |
3c0ef626 | 839 | { |
0fff78ff | 840 | Key *prv; |
841 | int ret; | |
700318f3 | 842 | |
0fff78ff | 843 | /* the agent supports this key */ |
844 | if (id->ac) | |
845 | return (ssh_agent_sign(id->ac, id->key, sigp, lenp, | |
846 | data, datalen)); | |
847 | /* | |
848 | * we have already loaded the private key or | |
849 | * the private key is stored in external hardware | |
850 | */ | |
851 | if (id->isprivate || (id->key->flags & KEY_FLAG_EXT)) | |
852 | return (key_sign(id->key, sigp, lenp, data, datalen)); | |
853 | /* load the private key from the file */ | |
854 | if ((prv = load_identity_file(id->filename)) == NULL) | |
855 | return (-1); | |
856 | ret = key_sign(prv, sigp, lenp, data, datalen); | |
857 | key_free(prv); | |
858 | return (ret); | |
3c0ef626 | 859 | } |
860 | ||
861 | static int | |
0fff78ff | 862 | sign_and_send_pubkey(Authctxt *authctxt, Identity *id) |
3c0ef626 | 863 | { |
864 | Buffer b; | |
865 | u_char *blob, *signature; | |
e9a17296 | 866 | u_int bloblen, slen; |
0fff78ff | 867 | u_int skip = 0; |
3c0ef626 | 868 | int ret = -1; |
869 | int have_sig = 1; | |
870 | ||
871 | debug3("sign_and_send_pubkey"); | |
872 | ||
0fff78ff | 873 | if (key_to_blob(id->key, &blob, &bloblen) == 0) { |
3c0ef626 | 874 | /* we cannot handle this key */ |
875 | debug3("sign_and_send_pubkey: cannot handle key"); | |
876 | return 0; | |
877 | } | |
878 | /* data to be signed */ | |
879 | buffer_init(&b); | |
880 | if (datafellows & SSH_OLD_SESSIONID) { | |
881 | buffer_append(&b, session_id2, session_id2_len); | |
882 | skip = session_id2_len; | |
883 | } else { | |
884 | buffer_put_string(&b, session_id2, session_id2_len); | |
885 | skip = buffer_len(&b); | |
886 | } | |
887 | buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST); | |
888 | buffer_put_cstring(&b, authctxt->server_user); | |
889 | buffer_put_cstring(&b, | |
890 | datafellows & SSH_BUG_PKSERVICE ? | |
891 | "ssh-userauth" : | |
892 | authctxt->service); | |
893 | if (datafellows & SSH_BUG_PKAUTH) { | |
894 | buffer_put_char(&b, have_sig); | |
895 | } else { | |
896 | buffer_put_cstring(&b, authctxt->method->name); | |
897 | buffer_put_char(&b, have_sig); | |
0fff78ff | 898 | buffer_put_cstring(&b, key_ssh_name(id->key)); |
3c0ef626 | 899 | } |
900 | buffer_put_string(&b, blob, bloblen); | |
901 | ||
902 | /* generate signature */ | |
0fff78ff | 903 | ret = identity_sign(id, &signature, &slen, |
3c0ef626 | 904 | buffer_ptr(&b), buffer_len(&b)); |
905 | if (ret == -1) { | |
906 | xfree(blob); | |
907 | buffer_free(&b); | |
908 | return 0; | |
909 | } | |
910 | #ifdef DEBUG_PK | |
911 | buffer_dump(&b); | |
912 | #endif | |
913 | if (datafellows & SSH_BUG_PKSERVICE) { | |
914 | buffer_clear(&b); | |
915 | buffer_append(&b, session_id2, session_id2_len); | |
916 | skip = session_id2_len; | |
917 | buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST); | |
918 | buffer_put_cstring(&b, authctxt->server_user); | |
919 | buffer_put_cstring(&b, authctxt->service); | |
920 | buffer_put_cstring(&b, authctxt->method->name); | |
921 | buffer_put_char(&b, have_sig); | |
922 | if (!(datafellows & SSH_BUG_PKAUTH)) | |
0fff78ff | 923 | buffer_put_cstring(&b, key_ssh_name(id->key)); |
3c0ef626 | 924 | buffer_put_string(&b, blob, bloblen); |
925 | } | |
926 | xfree(blob); | |
927 | ||
928 | /* append signature */ | |
929 | buffer_put_string(&b, signature, slen); | |
930 | xfree(signature); | |
931 | ||
932 | /* skip session id and packet type */ | |
933 | if (buffer_len(&b) < skip + 1) | |
934 | fatal("userauth_pubkey: internal error"); | |
935 | buffer_consume(&b, skip + 1); | |
936 | ||
937 | /* put remaining data from buffer into packet */ | |
938 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
939 | packet_put_raw(buffer_ptr(&b), buffer_len(&b)); | |
940 | buffer_free(&b); | |
941 | packet_send(); | |
942 | ||
943 | return 1; | |
944 | } | |
945 | ||
946 | static int | |
0fff78ff | 947 | send_pubkey_test(Authctxt *authctxt, Identity *id) |
3c0ef626 | 948 | { |
949 | u_char *blob; | |
e9a17296 | 950 | u_int bloblen, have_sig = 0; |
3c0ef626 | 951 | |
952 | debug3("send_pubkey_test"); | |
953 | ||
0fff78ff | 954 | if (key_to_blob(id->key, &blob, &bloblen) == 0) { |
3c0ef626 | 955 | /* we cannot handle this key */ |
956 | debug3("send_pubkey_test: cannot handle key"); | |
957 | return 0; | |
958 | } | |
959 | /* register callback for USERAUTH_PK_OK message */ | |
3c0ef626 | 960 | dispatch_set(SSH2_MSG_USERAUTH_PK_OK, &input_userauth_pk_ok); |
961 | ||
962 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
963 | packet_put_cstring(authctxt->server_user); | |
964 | packet_put_cstring(authctxt->service); | |
965 | packet_put_cstring(authctxt->method->name); | |
966 | packet_put_char(have_sig); | |
967 | if (!(datafellows & SSH_BUG_PKAUTH)) | |
0fff78ff | 968 | packet_put_cstring(key_ssh_name(id->key)); |
3c0ef626 | 969 | packet_put_string(blob, bloblen); |
970 | xfree(blob); | |
971 | packet_send(); | |
972 | return 1; | |
973 | } | |
974 | ||
975 | static Key * | |
976 | load_identity_file(char *filename) | |
977 | { | |
978 | Key *private; | |
979 | char prompt[300], *passphrase; | |
980 | int quit, i; | |
981 | struct stat st; | |
982 | ||
983 | if (stat(filename, &st) < 0) { | |
984 | debug3("no such identity: %s", filename); | |
985 | return NULL; | |
986 | } | |
987 | private = key_load_private_type(KEY_UNSPEC, filename, "", NULL); | |
988 | if (private == NULL) { | |
989 | if (options.batch_mode) | |
990 | return NULL; | |
991 | snprintf(prompt, sizeof prompt, | |
e9a17296 | 992 | "Enter passphrase for key '%.100s': ", filename); |
3c0ef626 | 993 | for (i = 0; i < options.number_of_password_prompts; i++) { |
994 | passphrase = read_passphrase(prompt, 0); | |
995 | if (strcmp(passphrase, "") != 0) { | |
996 | private = key_load_private_type(KEY_UNSPEC, filename, | |
997 | passphrase, NULL); | |
998 | quit = 0; | |
999 | } else { | |
1000 | debug2("no passphrase given, try next key"); | |
1001 | quit = 1; | |
1002 | } | |
1003 | memset(passphrase, 0, strlen(passphrase)); | |
1004 | xfree(passphrase); | |
1005 | if (private != NULL || quit) | |
1006 | break; | |
1007 | debug2("bad passphrase given, try again..."); | |
1008 | } | |
1009 | } | |
1010 | return private; | |
1011 | } | |
1012 | ||
0fff78ff | 1013 | /* |
1014 | * try keys in the following order: | |
1015 | * 1. agent keys that are found in the config file | |
1016 | * 2. other agent keys | |
1017 | * 3. keys that are only listed in the config file | |
1018 | */ | |
1019 | static void | |
1020 | pubkey_prepare(Authctxt *authctxt) | |
3c0ef626 | 1021 | { |
0fff78ff | 1022 | Identity *id; |
1023 | Idlist agent, files, *preferred; | |
1024 | Key *key; | |
1025 | AuthenticationConnection *ac; | |
1026 | char *comment; | |
1027 | int i, found; | |
1028 | ||
1029 | TAILQ_INIT(&agent); /* keys from the agent */ | |
1030 | TAILQ_INIT(&files); /* keys from the config file */ | |
1031 | preferred = &authctxt->keys; | |
1032 | TAILQ_INIT(preferred); /* preferred order of keys */ | |
1033 | ||
1034 | /* list of keys stored in the filesystem */ | |
1035 | for (i = 0; i < options.num_identity_files; i++) { | |
1036 | key = options.identity_keys[i]; | |
1037 | if (key && key->type == KEY_RSA1) | |
1038 | continue; | |
1039 | options.identity_keys[i] = NULL; | |
1040 | id = xmalloc(sizeof(*id)); | |
1041 | memset(id, 0, sizeof(*id)); | |
1042 | id->key = key; | |
1043 | id->filename = xstrdup(options.identity_files[i]); | |
1044 | TAILQ_INSERT_TAIL(&files, id, next); | |
1045 | } | |
1046 | /* list of keys supported by the agent */ | |
1047 | if ((ac = ssh_get_authentication_connection())) { | |
1048 | for (key = ssh_get_first_identity(ac, &comment, 2); | |
1049 | key != NULL; | |
1050 | key = ssh_get_next_identity(ac, &comment, 2)) { | |
1051 | found = 0; | |
1052 | TAILQ_FOREACH(id, &files, next) { | |
cdd66111 | 1053 | /* agent keys from the config file are preferred */ |
0fff78ff | 1054 | if (key_equal(key, id->key)) { |
1055 | key_free(key); | |
1056 | xfree(comment); | |
1057 | TAILQ_REMOVE(&files, id, next); | |
1058 | TAILQ_INSERT_TAIL(preferred, id, next); | |
1059 | id->ac = ac; | |
1060 | found = 1; | |
1061 | break; | |
1062 | } | |
1063 | } | |
99be0775 | 1064 | if (!found && !options.identities_only) { |
0fff78ff | 1065 | id = xmalloc(sizeof(*id)); |
1066 | memset(id, 0, sizeof(*id)); | |
1067 | id->key = key; | |
1068 | id->filename = comment; | |
1069 | id->ac = ac; | |
1070 | TAILQ_INSERT_TAIL(&agent, id, next); | |
1071 | } | |
1072 | } | |
1073 | /* append remaining agent keys */ | |
1074 | for (id = TAILQ_FIRST(&agent); id; id = TAILQ_FIRST(&agent)) { | |
1075 | TAILQ_REMOVE(&agent, id, next); | |
1076 | TAILQ_INSERT_TAIL(preferred, id, next); | |
1077 | } | |
1078 | authctxt->agent = ac; | |
1079 | } | |
1080 | /* append remaining keys from the config file */ | |
1081 | for (id = TAILQ_FIRST(&files); id; id = TAILQ_FIRST(&files)) { | |
1082 | TAILQ_REMOVE(&files, id, next); | |
1083 | TAILQ_INSERT_TAIL(preferred, id, next); | |
1084 | } | |
1085 | TAILQ_FOREACH(id, preferred, next) { | |
1086 | debug2("key: %s (%p)", id->filename, id->key); | |
1087 | } | |
3c0ef626 | 1088 | } |
1089 | ||
0fff78ff | 1090 | static void |
1091 | pubkey_cleanup(Authctxt *authctxt) | |
3c0ef626 | 1092 | { |
0fff78ff | 1093 | Identity *id; |
1094 | ||
1095 | if (authctxt->agent != NULL) | |
1096 | ssh_close_authentication_connection(authctxt->agent); | |
1097 | for (id = TAILQ_FIRST(&authctxt->keys); id; | |
1098 | id = TAILQ_FIRST(&authctxt->keys)) { | |
1099 | TAILQ_REMOVE(&authctxt->keys, id, next); | |
1100 | if (id->key) | |
1101 | key_free(id->key); | |
1102 | if (id->filename) | |
1103 | xfree(id->filename); | |
1104 | xfree(id); | |
3c0ef626 | 1105 | } |
3c0ef626 | 1106 | } |
1107 | ||
1108 | int | |
1109 | userauth_pubkey(Authctxt *authctxt) | |
1110 | { | |
0fff78ff | 1111 | Identity *id; |
3c0ef626 | 1112 | int sent = 0; |
0fff78ff | 1113 | |
1114 | while ((id = TAILQ_FIRST(&authctxt->keys))) { | |
1115 | if (id->tried++) | |
1116 | return (0); | |
cdd66111 | 1117 | /* move key to the end of the queue */ |
0fff78ff | 1118 | TAILQ_REMOVE(&authctxt->keys, id, next); |
1119 | TAILQ_INSERT_TAIL(&authctxt->keys, id, next); | |
1120 | /* | |
1121 | * send a test message if we have the public key. for | |
1122 | * encrypted keys we cannot do this and have to load the | |
1123 | * private key instead | |
1124 | */ | |
1125 | if (id->key && id->key->type != KEY_RSA1) { | |
1126 | debug("Offering public key: %s", id->filename); | |
1127 | sent = send_pubkey_test(authctxt, id); | |
1128 | } else if (id->key == NULL) { | |
1129 | debug("Trying private key: %s", id->filename); | |
1130 | id->key = load_identity_file(id->filename); | |
1131 | if (id->key != NULL) { | |
1132 | id->isprivate = 1; | |
1133 | sent = sign_and_send_pubkey(authctxt, id); | |
1134 | key_free(id->key); | |
1135 | id->key = NULL; | |
3c0ef626 | 1136 | } |
3c0ef626 | 1137 | } |
0fff78ff | 1138 | if (sent) |
1139 | return (sent); | |
3c0ef626 | 1140 | } |
0fff78ff | 1141 | return (0); |
3c0ef626 | 1142 | } |
1143 | ||
1144 | /* | |
1145 | * Send userauth request message specifying keyboard-interactive method. | |
1146 | */ | |
1147 | int | |
1148 | userauth_kbdint(Authctxt *authctxt) | |
1149 | { | |
1150 | static int attempt = 0; | |
1151 | ||
1152 | if (attempt++ >= options.number_of_password_prompts) | |
1153 | return 0; | |
1154 | /* disable if no SSH2_MSG_USERAUTH_INFO_REQUEST has been seen */ | |
1155 | if (attempt > 1 && !authctxt->info_req_seen) { | |
1156 | debug3("userauth_kbdint: disable: no info_req_seen"); | |
1157 | dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, NULL); | |
1158 | return 0; | |
1159 | } | |
1160 | ||
1161 | debug2("userauth_kbdint"); | |
1162 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
1163 | packet_put_cstring(authctxt->server_user); | |
1164 | packet_put_cstring(authctxt->service); | |
1165 | packet_put_cstring(authctxt->method->name); | |
1166 | packet_put_cstring(""); /* lang */ | |
1167 | packet_put_cstring(options.kbd_interactive_devices ? | |
1168 | options.kbd_interactive_devices : ""); | |
1169 | packet_send(); | |
1170 | ||
1171 | dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, &input_userauth_info_req); | |
1172 | return 1; | |
1173 | } | |
1174 | ||
1175 | /* | |
1176 | * parse INFO_REQUEST, prompt user and send INFO_RESPONSE | |
1177 | */ | |
1178 | void | |
e9a17296 | 1179 | input_userauth_info_req(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 1180 | { |
1181 | Authctxt *authctxt = ctxt; | |
1182 | char *name, *inst, *lang, *prompt, *response; | |
1183 | u_int num_prompts, i; | |
1184 | int echo = 0; | |
1185 | ||
1186 | debug2("input_userauth_info_req"); | |
1187 | ||
1188 | if (authctxt == NULL) | |
1189 | fatal("input_userauth_info_req: no authentication context"); | |
1190 | ||
1191 | authctxt->info_req_seen = 1; | |
1192 | ||
1193 | name = packet_get_string(NULL); | |
1194 | inst = packet_get_string(NULL); | |
1195 | lang = packet_get_string(NULL); | |
1196 | if (strlen(name) > 0) | |
0fff78ff | 1197 | logit("%s", name); |
3c0ef626 | 1198 | if (strlen(inst) > 0) |
0fff78ff | 1199 | logit("%s", inst); |
3c0ef626 | 1200 | xfree(name); |
1201 | xfree(inst); | |
1202 | xfree(lang); | |
1203 | ||
1204 | num_prompts = packet_get_int(); | |
1205 | /* | |
1206 | * Begin to build info response packet based on prompts requested. | |
1207 | * We commit to providing the correct number of responses, so if | |
1208 | * further on we run into a problem that prevents this, we have to | |
1209 | * be sure and clean this up and send a correct error response. | |
1210 | */ | |
1211 | packet_start(SSH2_MSG_USERAUTH_INFO_RESPONSE); | |
1212 | packet_put_int(num_prompts); | |
1213 | ||
1214 | debug2("input_userauth_info_req: num_prompts %d", num_prompts); | |
1215 | for (i = 0; i < num_prompts; i++) { | |
1216 | prompt = packet_get_string(NULL); | |
1217 | echo = packet_get_char(); | |
1218 | ||
1219 | response = read_passphrase(prompt, echo ? RP_ECHO : 0); | |
1220 | ||
1221 | packet_put_cstring(response); | |
1222 | memset(response, 0, strlen(response)); | |
1223 | xfree(response); | |
1224 | xfree(prompt); | |
1225 | } | |
e9a17296 | 1226 | packet_check_eom(); /* done with parsing incoming message. */ |
3c0ef626 | 1227 | |
1228 | packet_add_padding(64); | |
1229 | packet_send(); | |
1230 | } | |
1231 | ||
f5799ae1 | 1232 | static int |
680cee3b | 1233 | ssh_keysign(Key *key, u_char **sigp, u_int *lenp, |
f5799ae1 | 1234 | u_char *data, u_int datalen) |
1235 | { | |
1236 | Buffer b; | |
1237 | struct stat st; | |
1238 | pid_t pid; | |
1239 | int to[2], from[2], status, version = 2; | |
1240 | ||
6a9b3198 | 1241 | debug2("ssh_keysign called"); |
f5799ae1 | 1242 | |
1243 | if (stat(_PATH_SSH_KEY_SIGN, &st) < 0) { | |
1244 | error("ssh_keysign: no installed: %s", strerror(errno)); | |
1245 | return -1; | |
1246 | } | |
1247 | if (fflush(stdout) != 0) | |
1248 | error("ssh_keysign: fflush: %s", strerror(errno)); | |
1249 | if (pipe(to) < 0) { | |
1250 | error("ssh_keysign: pipe: %s", strerror(errno)); | |
1251 | return -1; | |
1252 | } | |
1253 | if (pipe(from) < 0) { | |
1254 | error("ssh_keysign: pipe: %s", strerror(errno)); | |
1255 | return -1; | |
1256 | } | |
1257 | if ((pid = fork()) < 0) { | |
1258 | error("ssh_keysign: fork: %s", strerror(errno)); | |
1259 | return -1; | |
1260 | } | |
1261 | if (pid == 0) { | |
1262 | seteuid(getuid()); | |
1263 | setuid(getuid()); | |
1264 | close(from[0]); | |
1265 | if (dup2(from[1], STDOUT_FILENO) < 0) | |
1266 | fatal("ssh_keysign: dup2: %s", strerror(errno)); | |
1267 | close(to[1]); | |
1268 | if (dup2(to[0], STDIN_FILENO) < 0) | |
1269 | fatal("ssh_keysign: dup2: %s", strerror(errno)); | |
1270 | close(from[1]); | |
1271 | close(to[0]); | |
1272 | execl(_PATH_SSH_KEY_SIGN, _PATH_SSH_KEY_SIGN, (char *) 0); | |
1273 | fatal("ssh_keysign: exec(%s): %s", _PATH_SSH_KEY_SIGN, | |
1274 | strerror(errno)); | |
1275 | } | |
1276 | close(from[1]); | |
1277 | close(to[0]); | |
1278 | ||
1279 | buffer_init(&b); | |
1280 | buffer_put_int(&b, packet_get_connection_in()); /* send # of socket */ | |
1281 | buffer_put_string(&b, data, datalen); | |
cdd66111 | 1282 | if (ssh_msg_send(to[1], version, &b) == -1) |
1283 | fatal("ssh_keysign: couldn't send request"); | |
f5799ae1 | 1284 | |
41b2f314 | 1285 | if (ssh_msg_recv(from[0], &b) < 0) { |
f5799ae1 | 1286 | error("ssh_keysign: no reply"); |
cdd66111 | 1287 | buffer_free(&b); |
f5799ae1 | 1288 | return -1; |
1289 | } | |
1290 | close(from[0]); | |
1291 | close(to[1]); | |
1292 | ||
1293 | while (waitpid(pid, &status, 0) < 0) | |
1294 | if (errno != EINTR) | |
1295 | break; | |
1296 | ||
1297 | if (buffer_get_char(&b) != version) { | |
1298 | error("ssh_keysign: bad version"); | |
cdd66111 | 1299 | buffer_free(&b); |
f5799ae1 | 1300 | return -1; |
1301 | } | |
1302 | *sigp = buffer_get_string(&b, lenp); | |
cdd66111 | 1303 | buffer_free(&b); |
f5799ae1 | 1304 | |
1305 | return 0; | |
1306 | } | |
1307 | ||
3c0ef626 | 1308 | int |
1309 | userauth_hostbased(Authctxt *authctxt) | |
1310 | { | |
1311 | Key *private = NULL; | |
f5799ae1 | 1312 | Sensitive *sensitive = authctxt->sensitive; |
3c0ef626 | 1313 | Buffer b; |
1314 | u_char *signature, *blob; | |
1315 | char *chost, *pkalg, *p; | |
1316 | const char *service; | |
1317 | u_int blen, slen; | |
1318 | int ok, i, len, found = 0; | |
1319 | ||
1320 | /* check for a useful key */ | |
f5799ae1 | 1321 | for (i = 0; i < sensitive->nkeys; i++) { |
1322 | private = sensitive->keys[i]; | |
3c0ef626 | 1323 | if (private && private->type != KEY_RSA1) { |
1324 | found = 1; | |
1325 | /* we take and free the key */ | |
f5799ae1 | 1326 | sensitive->keys[i] = NULL; |
3c0ef626 | 1327 | break; |
1328 | } | |
1329 | } | |
1330 | if (!found) { | |
6a9b3198 | 1331 | debug("No more client hostkeys for hostbased authentication."); |
3c0ef626 | 1332 | return 0; |
1333 | } | |
1334 | if (key_to_blob(private, &blob, &blen) == 0) { | |
1335 | key_free(private); | |
1336 | return 0; | |
1337 | } | |
1338 | /* figure out a name for the client host */ | |
1339 | p = get_local_name(packet_get_connection_in()); | |
1340 | if (p == NULL) { | |
1341 | error("userauth_hostbased: cannot get local ipaddr/name"); | |
1342 | key_free(private); | |
1343 | return 0; | |
1344 | } | |
1345 | len = strlen(p) + 2; | |
1346 | chost = xmalloc(len); | |
1347 | strlcpy(chost, p, len); | |
1348 | strlcat(chost, ".", len); | |
1349 | debug2("userauth_hostbased: chost %s", chost); | |
6a9b3198 | 1350 | xfree(p); |
3c0ef626 | 1351 | |
1352 | service = datafellows & SSH_BUG_HBSERVICE ? "ssh-userauth" : | |
1353 | authctxt->service; | |
1354 | pkalg = xstrdup(key_ssh_name(private)); | |
1355 | buffer_init(&b); | |
1356 | /* construct data */ | |
1357 | buffer_put_string(&b, session_id2, session_id2_len); | |
1358 | buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST); | |
1359 | buffer_put_cstring(&b, authctxt->server_user); | |
1360 | buffer_put_cstring(&b, service); | |
1361 | buffer_put_cstring(&b, authctxt->method->name); | |
1362 | buffer_put_cstring(&b, pkalg); | |
1363 | buffer_put_string(&b, blob, blen); | |
1364 | buffer_put_cstring(&b, chost); | |
1365 | buffer_put_cstring(&b, authctxt->local_user); | |
1366 | #ifdef DEBUG_PK | |
1367 | buffer_dump(&b); | |
1368 | #endif | |
f5799ae1 | 1369 | if (sensitive->external_keysign) |
1370 | ok = ssh_keysign(private, &signature, &slen, | |
1371 | buffer_ptr(&b), buffer_len(&b)); | |
1372 | else | |
1373 | ok = key_sign(private, &signature, &slen, | |
1374 | buffer_ptr(&b), buffer_len(&b)); | |
3c0ef626 | 1375 | key_free(private); |
1376 | buffer_free(&b); | |
1377 | if (ok != 0) { | |
1378 | error("key_sign failed"); | |
1379 | xfree(chost); | |
1380 | xfree(pkalg); | |
1381 | return 0; | |
1382 | } | |
1383 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
1384 | packet_put_cstring(authctxt->server_user); | |
1385 | packet_put_cstring(authctxt->service); | |
1386 | packet_put_cstring(authctxt->method->name); | |
1387 | packet_put_cstring(pkalg); | |
1388 | packet_put_string(blob, blen); | |
1389 | packet_put_cstring(chost); | |
1390 | packet_put_cstring(authctxt->local_user); | |
1391 | packet_put_string(signature, slen); | |
1392 | memset(signature, 's', slen); | |
1393 | xfree(signature); | |
1394 | xfree(chost); | |
1395 | xfree(pkalg); | |
1396 | ||
1397 | packet_send(); | |
1398 | return 1; | |
1399 | } | |
1400 | ||
1401 | /* find auth method */ | |
1402 | ||
1403 | /* | |
1404 | * given auth method name, if configurable options permit this method fill | |
1405 | * in auth_ident field and return true, otherwise return false. | |
1406 | */ | |
1407 | static int | |
1408 | authmethod_is_enabled(Authmethod *method) | |
1409 | { | |
1410 | if (method == NULL) | |
1411 | return 0; | |
1412 | /* return false if options indicate this method is disabled */ | |
1413 | if (method->enabled == NULL || *method->enabled == 0) | |
1414 | return 0; | |
1415 | /* return false if batch mode is enabled but method needs interactive mode */ | |
1416 | if (method->batch_flag != NULL && *method->batch_flag != 0) | |
1417 | return 0; | |
1418 | return 1; | |
1419 | } | |
1420 | ||
1421 | static Authmethod * | |
1422 | authmethod_lookup(const char *name) | |
1423 | { | |
1424 | Authmethod *method = NULL; | |
1425 | if (name != NULL) | |
1426 | for (method = authmethods; method->name != NULL; method++) | |
1427 | if (strcmp(name, method->name) == 0) | |
1428 | return method; | |
1429 | debug2("Unrecognized authentication method name: %s", name ? name : "NULL"); | |
1430 | return NULL; | |
1431 | } | |
1432 | ||
1433 | /* XXX internal state */ | |
1434 | static Authmethod *current = NULL; | |
1435 | static char *supported = NULL; | |
1436 | static char *preferred = NULL; | |
680cee3b | 1437 | |
3c0ef626 | 1438 | /* |
1439 | * Given the authentication method list sent by the server, return the | |
1440 | * next method we should try. If the server initially sends a nil list, | |
1441 | * use a built-in default list. | |
1442 | */ | |
1443 | static Authmethod * | |
1444 | authmethod_get(char *authlist) | |
1445 | { | |
3c0ef626 | 1446 | char *name = NULL; |
e9a17296 | 1447 | u_int next; |
3c0ef626 | 1448 | |
1449 | /* Use a suitable default if we're passed a nil list. */ | |
1450 | if (authlist == NULL || strlen(authlist) == 0) | |
1451 | authlist = options.preferred_authentications; | |
1452 | ||
1453 | if (supported == NULL || strcmp(authlist, supported) != 0) { | |
1454 | debug3("start over, passed a different list %s", authlist); | |
1455 | if (supported != NULL) | |
1456 | xfree(supported); | |
1457 | supported = xstrdup(authlist); | |
1458 | preferred = options.preferred_authentications; | |
1459 | debug3("preferred %s", preferred); | |
1460 | current = NULL; | |
1461 | } else if (current != NULL && authmethod_is_enabled(current)) | |
1462 | return current; | |
1463 | ||
1464 | for (;;) { | |
1465 | if ((name = match_list(preferred, supported, &next)) == NULL) { | |
6a9b3198 | 1466 | debug("No more authentication methods to try."); |
3c0ef626 | 1467 | current = NULL; |
1468 | return NULL; | |
1469 | } | |
1470 | preferred += next; | |
1471 | debug3("authmethod_lookup %s", name); | |
1472 | debug3("remaining preferred: %s", preferred); | |
1473 | if ((current = authmethod_lookup(name)) != NULL && | |
1474 | authmethod_is_enabled(current)) { | |
1475 | debug3("authmethod_is_enabled %s", name); | |
6a9b3198 | 1476 | debug("Next authentication method: %s", name); |
3c0ef626 | 1477 | return current; |
1478 | } | |
1479 | } | |
1480 | } | |
1481 | ||
3c0ef626 | 1482 | static char * |
1483 | authmethods_get(void) | |
1484 | { | |
1485 | Authmethod *method = NULL; | |
e9a17296 | 1486 | Buffer b; |
1487 | char *list; | |
3c0ef626 | 1488 | |
e9a17296 | 1489 | buffer_init(&b); |
3c0ef626 | 1490 | for (method = authmethods; method->name != NULL; method++) { |
1491 | if (authmethod_is_enabled(method)) { | |
e9a17296 | 1492 | if (buffer_len(&b) > 0) |
1493 | buffer_append(&b, ",", 1); | |
1494 | buffer_append(&b, method->name, strlen(method->name)); | |
3c0ef626 | 1495 | } |
1496 | } | |
e9a17296 | 1497 | buffer_append(&b, "\0", 1); |
1498 | list = xstrdup(buffer_ptr(&b)); | |
1499 | buffer_free(&b); | |
1500 | return list; | |
3c0ef626 | 1501 | } |