]>
Commit | Line | Data |
---|---|---|
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" | |
c9f39d2c | 26 | RCSID("$OpenBSD: sshconnect2.c,v 1.138 2004/06/13 12:53:24 djm 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; | |
61 | ||
62 | /* | |
63 | * SSH2 key exchange | |
64 | */ | |
65 | ||
66 | u_char *session_id2 = NULL; | |
0fff78ff | 67 | u_int session_id2_len = 0; |
3c0ef626 | 68 | |
69 | char *xxx_host; | |
70 | struct sockaddr *xxx_hostaddr; | |
71 | ||
72 | Kex *xxx_kex = NULL; | |
73 | ||
74 | static int | |
75 | verify_host_key_callback(Key *hostkey) | |
76 | { | |
77 | if (verify_host_key(xxx_host, xxx_hostaddr, hostkey) == -1) | |
78 | fatal("Host key verification failed."); | |
79 | return 0; | |
80 | } | |
81 | ||
82 | void | |
83 | ssh_kex2(char *host, struct sockaddr *hostaddr) | |
84 | { | |
85 | Kex *kex; | |
86 | ||
87 | xxx_host = host; | |
88 | xxx_hostaddr = hostaddr; | |
89 | ||
90 | if (options.ciphers == (char *)-1) { | |
0fff78ff | 91 | logit("No valid ciphers for protocol version 2 given, using defaults."); |
3c0ef626 | 92 | options.ciphers = NULL; |
93 | } | |
94 | if (options.ciphers != NULL) { | |
95 | myproposal[PROPOSAL_ENC_ALGS_CTOS] = | |
96 | myproposal[PROPOSAL_ENC_ALGS_STOC] = options.ciphers; | |
97 | } | |
98 | myproposal[PROPOSAL_ENC_ALGS_CTOS] = | |
99 | compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_CTOS]); | |
100 | myproposal[PROPOSAL_ENC_ALGS_STOC] = | |
101 | compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_STOC]); | |
102 | if (options.compression) { | |
103 | myproposal[PROPOSAL_COMP_ALGS_CTOS] = | |
41b2f314 | 104 | myproposal[PROPOSAL_COMP_ALGS_STOC] = "zlib,none"; |
3c0ef626 | 105 | } else { |
106 | myproposal[PROPOSAL_COMP_ALGS_CTOS] = | |
41b2f314 | 107 | myproposal[PROPOSAL_COMP_ALGS_STOC] = "none,zlib"; |
3c0ef626 | 108 | } |
109 | if (options.macs != NULL) { | |
110 | myproposal[PROPOSAL_MAC_ALGS_CTOS] = | |
111 | myproposal[PROPOSAL_MAC_ALGS_STOC] = options.macs; | |
112 | } | |
113 | if (options.hostkeyalgorithms != NULL) | |
e9a17296 | 114 | myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = |
3c0ef626 | 115 | options.hostkeyalgorithms; |
116 | ||
0fff78ff | 117 | if (options.rekey_limit) |
118 | packet_set_rekey_limit(options.rekey_limit); | |
119 | ||
3c0ef626 | 120 | /* start key exchange */ |
121 | kex = kex_setup(myproposal); | |
6a9b3198 | 122 | kex->kex[KEX_DH_GRP1_SHA1] = kexdh_client; |
c9f39d2c | 123 | kex->kex[KEX_DH_GRP14_SHA1] = kexdh_client; |
6a9b3198 | 124 | kex->kex[KEX_DH_GEX_SHA1] = kexgex_client; |
3c0ef626 | 125 | kex->client_version_string=client_version_string; |
126 | kex->server_version_string=server_version_string; | |
127 | kex->verify_host_key=&verify_host_key_callback; | |
128 | ||
129 | xxx_kex = kex; | |
130 | ||
131 | dispatch_run(DISPATCH_BLOCK, &kex->done, kex); | |
132 | ||
133 | session_id2 = kex->session_id; | |
134 | session_id2_len = kex->session_id_len; | |
135 | ||
136 | #ifdef DEBUG_KEXDH | |
137 | /* send 1st encrypted/maced/compressed message */ | |
138 | packet_start(SSH2_MSG_IGNORE); | |
139 | packet_put_cstring("markus"); | |
140 | packet_send(); | |
141 | packet_write_wait(); | |
142 | #endif | |
3c0ef626 | 143 | } |
144 | ||
145 | /* | |
146 | * Authenticate user | |
147 | */ | |
148 | ||
149 | typedef struct Authctxt Authctxt; | |
150 | typedef struct Authmethod Authmethod; | |
0fff78ff | 151 | typedef struct identity Identity; |
152 | typedef struct idlist Idlist; | |
153 | ||
154 | struct identity { | |
155 | TAILQ_ENTRY(identity) next; | |
156 | AuthenticationConnection *ac; /* set if agent supports key */ | |
157 | Key *key; /* public/private key */ | |
158 | char *filename; /* comment for agent-only keys */ | |
159 | int tried; | |
160 | int isprivate; /* key points to the private key */ | |
161 | }; | |
162 | TAILQ_HEAD(idlist, identity); | |
3c0ef626 | 163 | |
164 | struct Authctxt { | |
165 | const char *server_user; | |
166 | const char *local_user; | |
167 | const char *host; | |
168 | const char *service; | |
169 | Authmethod *method; | |
170 | int success; | |
171 | char *authlist; | |
172 | /* pubkey */ | |
0fff78ff | 173 | Idlist keys; |
3c0ef626 | 174 | AuthenticationConnection *agent; |
175 | /* hostbased */ | |
f5799ae1 | 176 | Sensitive *sensitive; |
3c0ef626 | 177 | /* kbd-interactive */ |
178 | int info_req_seen; | |
0fff78ff | 179 | /* generic */ |
180 | void *methoddata; | |
3c0ef626 | 181 | }; |
182 | struct Authmethod { | |
183 | char *name; /* string to compare against server's list */ | |
184 | int (*userauth)(Authctxt *authctxt); | |
185 | int *enabled; /* flag in option struct that enables method */ | |
186 | int *batch_flag; /* flag in option struct that disables method */ | |
187 | }; | |
188 | ||
e9a17296 | 189 | void input_userauth_success(int, u_int32_t, void *); |
190 | void input_userauth_failure(int, u_int32_t, void *); | |
191 | void input_userauth_banner(int, u_int32_t, void *); | |
192 | void input_userauth_error(int, u_int32_t, void *); | |
193 | void input_userauth_info_req(int, u_int32_t, void *); | |
194 | void input_userauth_pk_ok(int, u_int32_t, void *); | |
700318f3 | 195 | void input_userauth_passwd_changereq(int, u_int32_t, void *); |
3c0ef626 | 196 | |
e9a17296 | 197 | int userauth_none(Authctxt *); |
198 | int userauth_pubkey(Authctxt *); | |
199 | int userauth_passwd(Authctxt *); | |
200 | int userauth_kbdint(Authctxt *); | |
201 | int userauth_hostbased(Authctxt *); | |
0fff78ff | 202 | int userauth_kerberos(Authctxt *); |
203 | ||
204 | #ifdef GSSAPI | |
205 | int userauth_gssapi(Authctxt *authctxt); | |
206 | void input_gssapi_response(int type, u_int32_t, void *); | |
207 | void input_gssapi_token(int type, u_int32_t, void *); | |
208 | void input_gssapi_hash(int type, u_int32_t, void *); | |
209 | void input_gssapi_error(int, u_int32_t, void *); | |
210 | void input_gssapi_errtok(int, u_int32_t, void *); | |
211 | #endif | |
3c0ef626 | 212 | |
e9a17296 | 213 | void userauth(Authctxt *, char *); |
3c0ef626 | 214 | |
0fff78ff | 215 | static int sign_and_send_pubkey(Authctxt *, Identity *); |
216 | static void pubkey_prepare(Authctxt *); | |
217 | static void pubkey_cleanup(Authctxt *); | |
218 | static Key *load_identity_file(char *); | |
3c0ef626 | 219 | |
220 | static Authmethod *authmethod_get(char *authlist); | |
221 | static Authmethod *authmethod_lookup(const char *name); | |
222 | static char *authmethods_get(void); | |
223 | ||
224 | Authmethod authmethods[] = { | |
0fff78ff | 225 | #ifdef GSSAPI |
cdd66111 | 226 | {"gssapi-with-mic", |
0fff78ff | 227 | userauth_gssapi, |
228 | &options.gss_authentication, | |
229 | NULL}, | |
230 | #endif | |
3c0ef626 | 231 | {"hostbased", |
232 | userauth_hostbased, | |
233 | &options.hostbased_authentication, | |
234 | NULL}, | |
235 | {"publickey", | |
236 | userauth_pubkey, | |
237 | &options.pubkey_authentication, | |
238 | NULL}, | |
239 | {"keyboard-interactive", | |
240 | userauth_kbdint, | |
241 | &options.kbd_interactive_authentication, | |
242 | &options.batch_mode}, | |
243 | {"password", | |
244 | userauth_passwd, | |
245 | &options.password_authentication, | |
246 | &options.batch_mode}, | |
247 | {"none", | |
248 | userauth_none, | |
249 | NULL, | |
250 | NULL}, | |
251 | {NULL, NULL, NULL, NULL} | |
252 | }; | |
253 | ||
254 | void | |
255 | ssh_userauth2(const char *local_user, const char *server_user, char *host, | |
f5799ae1 | 256 | Sensitive *sensitive) |
3c0ef626 | 257 | { |
258 | Authctxt authctxt; | |
259 | int type; | |
3c0ef626 | 260 | |
261 | if (options.challenge_response_authentication) | |
262 | options.kbd_interactive_authentication = 1; | |
263 | ||
3c0ef626 | 264 | packet_start(SSH2_MSG_SERVICE_REQUEST); |
265 | packet_put_cstring("ssh-userauth"); | |
266 | packet_send(); | |
6a9b3198 | 267 | debug("SSH2_MSG_SERVICE_REQUEST sent"); |
3c0ef626 | 268 | packet_write_wait(); |
e9a17296 | 269 | type = packet_read(); |
6a9b3198 | 270 | if (type != SSH2_MSG_SERVICE_ACCEPT) |
271 | fatal("Server denied authentication request: %d", type); | |
3c0ef626 | 272 | if (packet_remaining() > 0) { |
e9a17296 | 273 | char *reply = packet_get_string(NULL); |
6a9b3198 | 274 | debug2("service_accept: %s", reply); |
3c0ef626 | 275 | xfree(reply); |
276 | } else { | |
6a9b3198 | 277 | debug2("buggy server: service_accept w/o service"); |
3c0ef626 | 278 | } |
e9a17296 | 279 | packet_check_eom(); |
6a9b3198 | 280 | debug("SSH2_MSG_SERVICE_ACCEPT received"); |
3c0ef626 | 281 | |
282 | if (options.preferred_authentications == NULL) | |
283 | options.preferred_authentications = authmethods_get(); | |
284 | ||
285 | /* setup authentication context */ | |
286 | memset(&authctxt, 0, sizeof(authctxt)); | |
0fff78ff | 287 | pubkey_prepare(&authctxt); |
3c0ef626 | 288 | authctxt.server_user = server_user; |
289 | authctxt.local_user = local_user; | |
290 | authctxt.host = host; | |
291 | authctxt.service = "ssh-connection"; /* service name */ | |
292 | authctxt.success = 0; | |
293 | authctxt.method = authmethod_lookup("none"); | |
294 | authctxt.authlist = NULL; | |
0fff78ff | 295 | authctxt.methoddata = NULL; |
f5799ae1 | 296 | authctxt.sensitive = sensitive; |
3c0ef626 | 297 | authctxt.info_req_seen = 0; |
298 | if (authctxt.method == NULL) | |
299 | fatal("ssh_userauth2: internal error: cannot send userauth none request"); | |
300 | ||
301 | /* initial userauth request */ | |
302 | userauth_none(&authctxt); | |
303 | ||
304 | dispatch_init(&input_userauth_error); | |
305 | dispatch_set(SSH2_MSG_USERAUTH_SUCCESS, &input_userauth_success); | |
306 | dispatch_set(SSH2_MSG_USERAUTH_FAILURE, &input_userauth_failure); | |
307 | dispatch_set(SSH2_MSG_USERAUTH_BANNER, &input_userauth_banner); | |
308 | dispatch_run(DISPATCH_BLOCK, &authctxt.success, &authctxt); /* loop until success */ | |
309 | ||
0fff78ff | 310 | pubkey_cleanup(&authctxt); |
311 | dispatch_range(SSH2_MSG_USERAUTH_MIN, SSH2_MSG_USERAUTH_MAX, NULL); | |
3c0ef626 | 312 | |
6a9b3198 | 313 | debug("Authentication succeeded (%s).", authctxt.method->name); |
3c0ef626 | 314 | } |
0fff78ff | 315 | |
3c0ef626 | 316 | void |
317 | userauth(Authctxt *authctxt, char *authlist) | |
318 | { | |
0fff78ff | 319 | if (authctxt->methoddata) { |
320 | xfree(authctxt->methoddata); | |
321 | authctxt->methoddata = NULL; | |
322 | } | |
3c0ef626 | 323 | if (authlist == NULL) { |
324 | authlist = authctxt->authlist; | |
325 | } else { | |
326 | if (authctxt->authlist) | |
327 | xfree(authctxt->authlist); | |
328 | authctxt->authlist = authlist; | |
329 | } | |
330 | for (;;) { | |
331 | Authmethod *method = authmethod_get(authlist); | |
332 | if (method == NULL) | |
333 | fatal("Permission denied (%s).", authlist); | |
334 | authctxt->method = method; | |
0fff78ff | 335 | |
336 | /* reset the per method handler */ | |
337 | dispatch_range(SSH2_MSG_USERAUTH_PER_METHOD_MIN, | |
338 | SSH2_MSG_USERAUTH_PER_METHOD_MAX, NULL); | |
339 | ||
340 | /* and try new method */ | |
3c0ef626 | 341 | if (method->userauth(authctxt) != 0) { |
342 | debug2("we sent a %s packet, wait for reply", method->name); | |
343 | break; | |
344 | } else { | |
345 | debug2("we did not send a packet, disable method"); | |
346 | method->enabled = NULL; | |
347 | } | |
348 | } | |
349 | } | |
680cee3b | 350 | |
3c0ef626 | 351 | void |
e9a17296 | 352 | input_userauth_error(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 353 | { |
354 | fatal("input_userauth_error: bad message during authentication: " | |
355 | "type %d", type); | |
356 | } | |
680cee3b | 357 | |
3c0ef626 | 358 | void |
e9a17296 | 359 | input_userauth_banner(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 360 | { |
361 | char *msg, *lang; | |
cdd66111 | 362 | |
3c0ef626 | 363 | debug3("input_userauth_banner"); |
364 | msg = packet_get_string(NULL); | |
365 | lang = packet_get_string(NULL); | |
cdd66111 | 366 | if (options.log_level > SYSLOG_LEVEL_QUIET) |
367 | fprintf(stderr, "%s", msg); | |
3c0ef626 | 368 | xfree(msg); |
369 | xfree(lang); | |
370 | } | |
680cee3b | 371 | |
3c0ef626 | 372 | void |
e9a17296 | 373 | input_userauth_success(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 374 | { |
375 | Authctxt *authctxt = ctxt; | |
376 | if (authctxt == NULL) | |
377 | fatal("input_userauth_success: no authentication context"); | |
cdd66111 | 378 | if (authctxt->authlist) { |
3c0ef626 | 379 | xfree(authctxt->authlist); |
cdd66111 | 380 | authctxt->authlist = NULL; |
381 | } | |
382 | if (authctxt->methoddata) { | |
0fff78ff | 383 | xfree(authctxt->methoddata); |
cdd66111 | 384 | authctxt->methoddata = NULL; |
385 | } | |
3c0ef626 | 386 | authctxt->success = 1; /* break out */ |
387 | } | |
680cee3b | 388 | |
3c0ef626 | 389 | void |
e9a17296 | 390 | input_userauth_failure(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 391 | { |
392 | Authctxt *authctxt = ctxt; | |
393 | char *authlist = NULL; | |
394 | int partial; | |
395 | ||
396 | if (authctxt == NULL) | |
397 | fatal("input_userauth_failure: no authentication context"); | |
398 | ||
399 | authlist = packet_get_string(NULL); | |
400 | partial = packet_get_char(); | |
e9a17296 | 401 | packet_check_eom(); |
3c0ef626 | 402 | |
403 | if (partial != 0) | |
0fff78ff | 404 | logit("Authenticated with partial success."); |
6a9b3198 | 405 | debug("Authentications that can continue: %s", authlist); |
3c0ef626 | 406 | |
3c0ef626 | 407 | userauth(authctxt, authlist); |
408 | } | |
409 | void | |
e9a17296 | 410 | input_userauth_pk_ok(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 411 | { |
412 | Authctxt *authctxt = ctxt; | |
413 | Key *key = NULL; | |
0fff78ff | 414 | Identity *id = NULL; |
3c0ef626 | 415 | Buffer b; |
e9a17296 | 416 | int pktype, sent = 0; |
417 | u_int alen, blen; | |
418 | char *pkalg, *fp; | |
419 | u_char *pkblob; | |
3c0ef626 | 420 | |
421 | if (authctxt == NULL) | |
422 | fatal("input_userauth_pk_ok: no authentication context"); | |
423 | if (datafellows & SSH_BUG_PKOK) { | |
424 | /* this is similar to SSH_BUG_PKAUTH */ | |
425 | debug2("input_userauth_pk_ok: SSH_BUG_PKOK"); | |
426 | pkblob = packet_get_string(&blen); | |
427 | buffer_init(&b); | |
428 | buffer_append(&b, pkblob, blen); | |
429 | pkalg = buffer_get_string(&b, &alen); | |
430 | buffer_free(&b); | |
431 | } else { | |
432 | pkalg = packet_get_string(&alen); | |
433 | pkblob = packet_get_string(&blen); | |
434 | } | |
e9a17296 | 435 | packet_check_eom(); |
3c0ef626 | 436 | |
0fff78ff | 437 | debug("Server accepts key: pkalg %s blen %u", pkalg, blen); |
3c0ef626 | 438 | |
0fff78ff | 439 | if ((pktype = key_type_from_name(pkalg)) == KEY_UNSPEC) { |
440 | debug("unknown pkalg %s", pkalg); | |
441 | goto done; | |
442 | } | |
443 | if ((key = key_from_blob(pkblob, blen)) == NULL) { | |
444 | debug("no key from blob. pkalg %s", pkalg); | |
445 | goto done; | |
446 | } | |
447 | if (key->type != pktype) { | |
448 | error("input_userauth_pk_ok: type mismatch " | |
449 | "for decoded key (received %d, expected %d)", | |
450 | key->type, pktype); | |
451 | goto done; | |
452 | } | |
453 | fp = key_fingerprint(key, SSH_FP_MD5, SSH_FP_HEX); | |
454 | debug2("input_userauth_pk_ok: fp %s", fp); | |
455 | xfree(fp); | |
456 | ||
cdd66111 | 457 | /* |
458 | * search keys in the reverse order, because last candidate has been | |
459 | * moved to the end of the queue. this also avoids confusion by | |
460 | * duplicate keys | |
461 | */ | |
c9f39d2c | 462 | TAILQ_FOREACH_REVERSE(id, &authctxt->keys, idlist, next) { |
0fff78ff | 463 | if (key_equal(key, id->key)) { |
464 | sent = sign_and_send_pubkey(authctxt, id); | |
3c0ef626 | 465 | break; |
466 | } | |
0fff78ff | 467 | } |
468 | done: | |
3c0ef626 | 469 | if (key != NULL) |
470 | key_free(key); | |
471 | xfree(pkalg); | |
472 | xfree(pkblob); | |
473 | ||
41b2f314 | 474 | /* try another method if we did not send a packet */ |
3c0ef626 | 475 | if (sent == 0) |
476 | userauth(authctxt, NULL); | |
0fff78ff | 477 | } |
478 | ||
479 | #ifdef GSSAPI | |
cdd66111 | 480 | int |
0fff78ff | 481 | userauth_gssapi(Authctxt *authctxt) |
482 | { | |
483 | Gssctxt *gssctxt = NULL; | |
cdd66111 | 484 | static gss_OID_set gss_supported = NULL; |
0fff78ff | 485 | static int mech = 0; |
486 | OM_uint32 min; | |
487 | int ok = 0; | |
488 | ||
489 | /* Try one GSSAPI method at a time, rather than sending them all at | |
490 | * once. */ | |
491 | ||
cdd66111 | 492 | if (gss_supported == NULL) |
493 | gss_indicate_mechs(&min, &gss_supported); | |
0fff78ff | 494 | |
495 | /* Check to see if the mechanism is usable before we offer it */ | |
cdd66111 | 496 | while (mech < gss_supported->count && !ok) { |
0fff78ff | 497 | if (gssctxt) |
498 | ssh_gssapi_delete_ctx(&gssctxt); | |
499 | ssh_gssapi_build_ctx(&gssctxt); | |
cdd66111 | 500 | ssh_gssapi_set_oid(gssctxt, &gss_supported->elements[mech]); |
0fff78ff | 501 | |
502 | /* My DER encoding requires length<128 */ | |
cdd66111 | 503 | if (gss_supported->elements[mech].length < 128 && |
0fff78ff | 504 | !GSS_ERROR(ssh_gssapi_import_name(gssctxt, |
505 | authctxt->host))) { | |
506 | ok = 1; /* Mechanism works */ | |
507 | } else { | |
508 | mech++; | |
509 | } | |
510 | } | |
511 | ||
512 | if (!ok) 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 | packet_put_int(1); | |
522 | ||
cdd66111 | 523 | packet_put_int((gss_supported->elements[mech].length) + 2); |
524 | packet_put_char(SSH_GSS_OIDTYPE); | |
525 | packet_put_char(gss_supported->elements[mech].length); | |
526 | packet_put_raw(gss_supported->elements[mech].elements, | |
527 | gss_supported->elements[mech].length); | |
0fff78ff | 528 | |
529 | packet_send(); | |
530 | ||
531 | dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE, &input_gssapi_response); | |
532 | dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, &input_gssapi_token); | |
533 | dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERROR, &input_gssapi_error); | |
534 | dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, &input_gssapi_errtok); | |
535 | ||
536 | mech++; /* Move along to next candidate */ | |
537 | ||
538 | return 1; | |
539 | } | |
540 | ||
cdd66111 | 541 | static OM_uint32 |
542 | process_gssapi_token(void *ctxt, gss_buffer_t recv_tok) | |
543 | { | |
544 | Authctxt *authctxt = ctxt; | |
545 | Gssctxt *gssctxt = authctxt->methoddata; | |
546 | gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER; | |
547 | gss_buffer_desc gssbuf, mic; | |
548 | OM_uint32 status, ms, flags; | |
549 | Buffer b; | |
550 | ||
551 | status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds, | |
552 | recv_tok, &send_tok, &flags); | |
553 | ||
554 | if (send_tok.length > 0) { | |
555 | if (GSS_ERROR(status)) | |
556 | packet_start(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK); | |
557 | else | |
558 | packet_start(SSH2_MSG_USERAUTH_GSSAPI_TOKEN); | |
559 | ||
560 | packet_put_string(send_tok.value, send_tok.length); | |
561 | packet_send(); | |
562 | gss_release_buffer(&ms, &send_tok); | |
563 | } | |
564 | ||
565 | if (status == GSS_S_COMPLETE) { | |
566 | /* send either complete or MIC, depending on mechanism */ | |
567 | if (!(flags & GSS_C_INTEG_FLAG)) { | |
568 | packet_start(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE); | |
569 | packet_send(); | |
570 | } else { | |
571 | ssh_gssapi_buildmic(&b, authctxt->server_user, | |
572 | authctxt->service, "gssapi-with-mic"); | |
573 | ||
574 | gssbuf.value = buffer_ptr(&b); | |
575 | gssbuf.length = buffer_len(&b); | |
576 | ||
577 | status = ssh_gssapi_sign(gssctxt, &gssbuf, &mic); | |
578 | ||
579 | if (!GSS_ERROR(status)) { | |
580 | packet_start(SSH2_MSG_USERAUTH_GSSAPI_MIC); | |
581 | packet_put_string(mic.value, mic.length); | |
582 | ||
583 | packet_send(); | |
584 | } | |
585 | ||
586 | buffer_free(&b); | |
587 | gss_release_buffer(&ms, &mic); | |
588 | } | |
589 | } | |
590 | ||
591 | return status; | |
592 | } | |
593 | ||
0fff78ff | 594 | void |
595 | input_gssapi_response(int type, u_int32_t plen, void *ctxt) | |
596 | { | |
597 | Authctxt *authctxt = ctxt; | |
598 | Gssctxt *gssctxt; | |
0fff78ff | 599 | int oidlen; |
600 | char *oidv; | |
0fff78ff | 601 | |
602 | if (authctxt == NULL) | |
603 | fatal("input_gssapi_response: no authentication context"); | |
604 | gssctxt = authctxt->methoddata; | |
605 | ||
606 | /* Setup our OID */ | |
607 | oidv = packet_get_string(&oidlen); | |
608 | ||
cdd66111 | 609 | if (oidlen <= 2 || |
610 | oidv[0] != SSH_GSS_OIDTYPE || | |
611 | oidv[1] != oidlen - 2) { | |
612 | xfree(oidv); | |
613 | debug("Badly encoded mechanism OID received"); | |
614 | userauth(authctxt, NULL); | |
615 | return; | |
0fff78ff | 616 | } |
617 | ||
cdd66111 | 618 | if (!ssh_gssapi_check_oid(gssctxt, oidv + 2, oidlen - 2)) |
619 | fatal("Server returned different OID than expected"); | |
620 | ||
0fff78ff | 621 | packet_check_eom(); |
622 | ||
623 | xfree(oidv); | |
624 | ||
cdd66111 | 625 | if (GSS_ERROR(process_gssapi_token(ctxt, GSS_C_NO_BUFFER))) { |
0fff78ff | 626 | /* Start again with next method on list */ |
627 | debug("Trying to start again"); | |
628 | userauth(authctxt, NULL); | |
629 | return; | |
630 | } | |
0fff78ff | 631 | } |
632 | ||
633 | void | |
634 | input_gssapi_token(int type, u_int32_t plen, void *ctxt) | |
635 | { | |
636 | Authctxt *authctxt = ctxt; | |
0fff78ff | 637 | gss_buffer_desc recv_tok; |
cdd66111 | 638 | OM_uint32 status; |
0fff78ff | 639 | u_int slen; |
640 | ||
641 | if (authctxt == NULL) | |
642 | fatal("input_gssapi_response: no authentication context"); | |
0fff78ff | 643 | |
644 | recv_tok.value = packet_get_string(&slen); | |
645 | recv_tok.length = slen; /* safe typecast */ | |
646 | ||
647 | packet_check_eom(); | |
648 | ||
cdd66111 | 649 | status = process_gssapi_token(ctxt, &recv_tok); |
0fff78ff | 650 | |
651 | xfree(recv_tok.value); | |
652 | ||
653 | if (GSS_ERROR(status)) { | |
0fff78ff | 654 | /* Start again with the next method in the list */ |
655 | userauth(authctxt, NULL); | |
656 | return; | |
657 | } | |
3c0ef626 | 658 | } |
659 | ||
0fff78ff | 660 | void |
661 | input_gssapi_errtok(int type, u_int32_t plen, void *ctxt) | |
662 | { | |
663 | Authctxt *authctxt = ctxt; | |
664 | Gssctxt *gssctxt; | |
665 | gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER; | |
666 | gss_buffer_desc recv_tok; | |
667 | OM_uint32 status, ms; | |
668 | u_int len; | |
669 | ||
670 | if (authctxt == NULL) | |
671 | fatal("input_gssapi_response: no authentication context"); | |
672 | gssctxt = authctxt->methoddata; | |
673 | ||
674 | recv_tok.value = packet_get_string(&len); | |
675 | recv_tok.length = len; | |
676 | ||
677 | packet_check_eom(); | |
678 | ||
679 | /* Stick it into GSSAPI and see what it says */ | |
680 | status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds, | |
681 | &recv_tok, &send_tok, NULL); | |
682 | ||
683 | xfree(recv_tok.value); | |
684 | gss_release_buffer(&ms, &send_tok); | |
685 | ||
686 | /* Server will be returning a failed packet after this one */ | |
687 | } | |
688 | ||
689 | void | |
690 | input_gssapi_error(int type, u_int32_t plen, void *ctxt) | |
691 | { | |
692 | OM_uint32 maj, min; | |
693 | char *msg; | |
694 | char *lang; | |
695 | ||
696 | maj=packet_get_int(); | |
697 | min=packet_get_int(); | |
698 | msg=packet_get_string(NULL); | |
699 | lang=packet_get_string(NULL); | |
700 | ||
701 | packet_check_eom(); | |
702 | ||
703 | debug("Server GSSAPI Error:\n%s\n", msg); | |
704 | xfree(msg); | |
705 | xfree(lang); | |
706 | } | |
707 | #endif /* GSSAPI */ | |
708 | ||
3c0ef626 | 709 | int |
710 | userauth_none(Authctxt *authctxt) | |
711 | { | |
712 | /* initial userauth request */ | |
713 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
714 | packet_put_cstring(authctxt->server_user); | |
715 | packet_put_cstring(authctxt->service); | |
716 | packet_put_cstring(authctxt->method->name); | |
717 | packet_send(); | |
718 | return 1; | |
719 | } | |
720 | ||
721 | int | |
722 | userauth_passwd(Authctxt *authctxt) | |
723 | { | |
724 | static int attempt = 0; | |
700318f3 | 725 | char prompt[150]; |
3c0ef626 | 726 | char *password; |
727 | ||
728 | if (attempt++ >= options.number_of_password_prompts) | |
729 | return 0; | |
730 | ||
e9a17296 | 731 | if (attempt != 1) |
3c0ef626 | 732 | error("Permission denied, please try again."); |
733 | ||
734 | snprintf(prompt, sizeof(prompt), "%.30s@%.128s's password: ", | |
735 | authctxt->server_user, authctxt->host); | |
736 | password = read_passphrase(prompt, 0); | |
737 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
738 | packet_put_cstring(authctxt->server_user); | |
739 | packet_put_cstring(authctxt->service); | |
740 | packet_put_cstring(authctxt->method->name); | |
741 | packet_put_char(0); | |
742 | packet_put_cstring(password); | |
743 | memset(password, 0, strlen(password)); | |
744 | xfree(password); | |
745 | packet_add_padding(64); | |
746 | packet_send(); | |
700318f3 | 747 | |
f5799ae1 | 748 | dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, |
700318f3 | 749 | &input_userauth_passwd_changereq); |
750 | ||
3c0ef626 | 751 | return 1; |
752 | } | |
700318f3 | 753 | /* |
754 | * parse PASSWD_CHANGEREQ, prompt user and send SSH2_MSG_USERAUTH_REQUEST | |
755 | */ | |
756 | void | |
757 | input_userauth_passwd_changereq(int type, u_int32_t seqnr, void *ctxt) | |
758 | { | |
759 | Authctxt *authctxt = ctxt; | |
760 | char *info, *lang, *password = NULL, *retype = NULL; | |
761 | char prompt[150]; | |
762 | ||
763 | debug2("input_userauth_passwd_changereq"); | |
764 | ||
765 | if (authctxt == NULL) | |
766 | fatal("input_userauth_passwd_changereq: " | |
767 | "no authentication context"); | |
768 | ||
769 | info = packet_get_string(NULL); | |
770 | lang = packet_get_string(NULL); | |
771 | if (strlen(info) > 0) | |
0fff78ff | 772 | logit("%s", info); |
700318f3 | 773 | xfree(info); |
774 | xfree(lang); | |
775 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
776 | packet_put_cstring(authctxt->server_user); | |
777 | packet_put_cstring(authctxt->service); | |
778 | packet_put_cstring(authctxt->method->name); | |
779 | packet_put_char(1); /* additional info */ | |
f5799ae1 | 780 | snprintf(prompt, sizeof(prompt), |
700318f3 | 781 | "Enter %.30s@%.128s's old password: ", |
782 | authctxt->server_user, authctxt->host); | |
783 | password = read_passphrase(prompt, 0); | |
784 | packet_put_cstring(password); | |
785 | memset(password, 0, strlen(password)); | |
786 | xfree(password); | |
787 | password = NULL; | |
788 | while (password == NULL) { | |
f5799ae1 | 789 | snprintf(prompt, sizeof(prompt), |
700318f3 | 790 | "Enter %.30s@%.128s's new password: ", |
791 | authctxt->server_user, authctxt->host); | |
792 | password = read_passphrase(prompt, RP_ALLOW_EOF); | |
793 | if (password == NULL) { | |
794 | /* bail out */ | |
795 | return; | |
796 | } | |
f5799ae1 | 797 | snprintf(prompt, sizeof(prompt), |
700318f3 | 798 | "Retype %.30s@%.128s's new password: ", |
799 | authctxt->server_user, authctxt->host); | |
800 | retype = read_passphrase(prompt, 0); | |
801 | if (strcmp(password, retype) != 0) { | |
802 | memset(password, 0, strlen(password)); | |
803 | xfree(password); | |
0fff78ff | 804 | logit("Mismatch; try again, EOF to quit."); |
700318f3 | 805 | password = NULL; |
806 | } | |
807 | memset(retype, 0, strlen(retype)); | |
808 | xfree(retype); | |
809 | } | |
810 | packet_put_cstring(password); | |
811 | memset(password, 0, strlen(password)); | |
812 | xfree(password); | |
813 | packet_add_padding(64); | |
814 | packet_send(); | |
f5799ae1 | 815 | |
816 | dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, | |
700318f3 | 817 | &input_userauth_passwd_changereq); |
818 | } | |
3c0ef626 | 819 | |
0fff78ff | 820 | static int |
821 | identity_sign(Identity *id, u_char **sigp, u_int *lenp, | |
822 | u_char *data, u_int datalen) | |
3c0ef626 | 823 | { |
0fff78ff | 824 | Key *prv; |
825 | int ret; | |
700318f3 | 826 | |
0fff78ff | 827 | /* the agent supports this key */ |
828 | if (id->ac) | |
829 | return (ssh_agent_sign(id->ac, id->key, sigp, lenp, | |
830 | data, datalen)); | |
831 | /* | |
832 | * we have already loaded the private key or | |
833 | * the private key is stored in external hardware | |
834 | */ | |
835 | if (id->isprivate || (id->key->flags & KEY_FLAG_EXT)) | |
836 | return (key_sign(id->key, sigp, lenp, data, datalen)); | |
837 | /* load the private key from the file */ | |
838 | if ((prv = load_identity_file(id->filename)) == NULL) | |
839 | return (-1); | |
840 | ret = key_sign(prv, sigp, lenp, data, datalen); | |
841 | key_free(prv); | |
842 | return (ret); | |
3c0ef626 | 843 | } |
844 | ||
845 | static int | |
0fff78ff | 846 | sign_and_send_pubkey(Authctxt *authctxt, Identity *id) |
3c0ef626 | 847 | { |
848 | Buffer b; | |
849 | u_char *blob, *signature; | |
e9a17296 | 850 | u_int bloblen, slen; |
0fff78ff | 851 | u_int skip = 0; |
3c0ef626 | 852 | int ret = -1; |
853 | int have_sig = 1; | |
854 | ||
855 | debug3("sign_and_send_pubkey"); | |
856 | ||
0fff78ff | 857 | if (key_to_blob(id->key, &blob, &bloblen) == 0) { |
3c0ef626 | 858 | /* we cannot handle this key */ |
859 | debug3("sign_and_send_pubkey: cannot handle key"); | |
860 | return 0; | |
861 | } | |
862 | /* data to be signed */ | |
863 | buffer_init(&b); | |
864 | if (datafellows & SSH_OLD_SESSIONID) { | |
865 | buffer_append(&b, session_id2, session_id2_len); | |
866 | skip = session_id2_len; | |
867 | } else { | |
868 | buffer_put_string(&b, session_id2, session_id2_len); | |
869 | skip = buffer_len(&b); | |
870 | } | |
871 | buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST); | |
872 | buffer_put_cstring(&b, authctxt->server_user); | |
873 | buffer_put_cstring(&b, | |
874 | datafellows & SSH_BUG_PKSERVICE ? | |
875 | "ssh-userauth" : | |
876 | authctxt->service); | |
877 | if (datafellows & SSH_BUG_PKAUTH) { | |
878 | buffer_put_char(&b, have_sig); | |
879 | } else { | |
880 | buffer_put_cstring(&b, authctxt->method->name); | |
881 | buffer_put_char(&b, have_sig); | |
0fff78ff | 882 | buffer_put_cstring(&b, key_ssh_name(id->key)); |
3c0ef626 | 883 | } |
884 | buffer_put_string(&b, blob, bloblen); | |
885 | ||
886 | /* generate signature */ | |
0fff78ff | 887 | ret = identity_sign(id, &signature, &slen, |
3c0ef626 | 888 | buffer_ptr(&b), buffer_len(&b)); |
889 | if (ret == -1) { | |
890 | xfree(blob); | |
891 | buffer_free(&b); | |
892 | return 0; | |
893 | } | |
894 | #ifdef DEBUG_PK | |
895 | buffer_dump(&b); | |
896 | #endif | |
897 | if (datafellows & SSH_BUG_PKSERVICE) { | |
898 | buffer_clear(&b); | |
899 | buffer_append(&b, session_id2, session_id2_len); | |
900 | skip = session_id2_len; | |
901 | buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST); | |
902 | buffer_put_cstring(&b, authctxt->server_user); | |
903 | buffer_put_cstring(&b, authctxt->service); | |
904 | buffer_put_cstring(&b, authctxt->method->name); | |
905 | buffer_put_char(&b, have_sig); | |
906 | if (!(datafellows & SSH_BUG_PKAUTH)) | |
0fff78ff | 907 | buffer_put_cstring(&b, key_ssh_name(id->key)); |
3c0ef626 | 908 | buffer_put_string(&b, blob, bloblen); |
909 | } | |
910 | xfree(blob); | |
911 | ||
912 | /* append signature */ | |
913 | buffer_put_string(&b, signature, slen); | |
914 | xfree(signature); | |
915 | ||
916 | /* skip session id and packet type */ | |
917 | if (buffer_len(&b) < skip + 1) | |
918 | fatal("userauth_pubkey: internal error"); | |
919 | buffer_consume(&b, skip + 1); | |
920 | ||
921 | /* put remaining data from buffer into packet */ | |
922 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
923 | packet_put_raw(buffer_ptr(&b), buffer_len(&b)); | |
924 | buffer_free(&b); | |
925 | packet_send(); | |
926 | ||
927 | return 1; | |
928 | } | |
929 | ||
930 | static int | |
0fff78ff | 931 | send_pubkey_test(Authctxt *authctxt, Identity *id) |
3c0ef626 | 932 | { |
933 | u_char *blob; | |
e9a17296 | 934 | u_int bloblen, have_sig = 0; |
3c0ef626 | 935 | |
936 | debug3("send_pubkey_test"); | |
937 | ||
0fff78ff | 938 | if (key_to_blob(id->key, &blob, &bloblen) == 0) { |
3c0ef626 | 939 | /* we cannot handle this key */ |
940 | debug3("send_pubkey_test: cannot handle key"); | |
941 | return 0; | |
942 | } | |
943 | /* register callback for USERAUTH_PK_OK message */ | |
3c0ef626 | 944 | dispatch_set(SSH2_MSG_USERAUTH_PK_OK, &input_userauth_pk_ok); |
945 | ||
946 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
947 | packet_put_cstring(authctxt->server_user); | |
948 | packet_put_cstring(authctxt->service); | |
949 | packet_put_cstring(authctxt->method->name); | |
950 | packet_put_char(have_sig); | |
951 | if (!(datafellows & SSH_BUG_PKAUTH)) | |
0fff78ff | 952 | packet_put_cstring(key_ssh_name(id->key)); |
3c0ef626 | 953 | packet_put_string(blob, bloblen); |
954 | xfree(blob); | |
955 | packet_send(); | |
956 | return 1; | |
957 | } | |
958 | ||
959 | static Key * | |
960 | load_identity_file(char *filename) | |
961 | { | |
962 | Key *private; | |
963 | char prompt[300], *passphrase; | |
964 | int quit, i; | |
965 | struct stat st; | |
966 | ||
967 | if (stat(filename, &st) < 0) { | |
968 | debug3("no such identity: %s", filename); | |
969 | return NULL; | |
970 | } | |
971 | private = key_load_private_type(KEY_UNSPEC, filename, "", NULL); | |
972 | if (private == NULL) { | |
973 | if (options.batch_mode) | |
974 | return NULL; | |
975 | snprintf(prompt, sizeof prompt, | |
e9a17296 | 976 | "Enter passphrase for key '%.100s': ", filename); |
3c0ef626 | 977 | for (i = 0; i < options.number_of_password_prompts; i++) { |
978 | passphrase = read_passphrase(prompt, 0); | |
979 | if (strcmp(passphrase, "") != 0) { | |
980 | private = key_load_private_type(KEY_UNSPEC, filename, | |
981 | passphrase, NULL); | |
982 | quit = 0; | |
983 | } else { | |
984 | debug2("no passphrase given, try next key"); | |
985 | quit = 1; | |
986 | } | |
987 | memset(passphrase, 0, strlen(passphrase)); | |
988 | xfree(passphrase); | |
989 | if (private != NULL || quit) | |
990 | break; | |
991 | debug2("bad passphrase given, try again..."); | |
992 | } | |
993 | } | |
994 | return private; | |
995 | } | |
996 | ||
0fff78ff | 997 | /* |
998 | * try keys in the following order: | |
999 | * 1. agent keys that are found in the config file | |
1000 | * 2. other agent keys | |
1001 | * 3. keys that are only listed in the config file | |
1002 | */ | |
1003 | static void | |
1004 | pubkey_prepare(Authctxt *authctxt) | |
3c0ef626 | 1005 | { |
0fff78ff | 1006 | Identity *id; |
1007 | Idlist agent, files, *preferred; | |
1008 | Key *key; | |
1009 | AuthenticationConnection *ac; | |
1010 | char *comment; | |
1011 | int i, found; | |
1012 | ||
1013 | TAILQ_INIT(&agent); /* keys from the agent */ | |
1014 | TAILQ_INIT(&files); /* keys from the config file */ | |
1015 | preferred = &authctxt->keys; | |
1016 | TAILQ_INIT(preferred); /* preferred order of keys */ | |
1017 | ||
1018 | /* list of keys stored in the filesystem */ | |
1019 | for (i = 0; i < options.num_identity_files; i++) { | |
1020 | key = options.identity_keys[i]; | |
1021 | if (key && key->type == KEY_RSA1) | |
1022 | continue; | |
1023 | options.identity_keys[i] = NULL; | |
1024 | id = xmalloc(sizeof(*id)); | |
1025 | memset(id, 0, sizeof(*id)); | |
1026 | id->key = key; | |
1027 | id->filename = xstrdup(options.identity_files[i]); | |
1028 | TAILQ_INSERT_TAIL(&files, id, next); | |
1029 | } | |
1030 | /* list of keys supported by the agent */ | |
1031 | if ((ac = ssh_get_authentication_connection())) { | |
1032 | for (key = ssh_get_first_identity(ac, &comment, 2); | |
1033 | key != NULL; | |
1034 | key = ssh_get_next_identity(ac, &comment, 2)) { | |
1035 | found = 0; | |
1036 | TAILQ_FOREACH(id, &files, next) { | |
cdd66111 | 1037 | /* agent keys from the config file are preferred */ |
0fff78ff | 1038 | if (key_equal(key, id->key)) { |
1039 | key_free(key); | |
1040 | xfree(comment); | |
1041 | TAILQ_REMOVE(&files, id, next); | |
1042 | TAILQ_INSERT_TAIL(preferred, id, next); | |
1043 | id->ac = ac; | |
1044 | found = 1; | |
1045 | break; | |
1046 | } | |
1047 | } | |
99be0775 | 1048 | if (!found && !options.identities_only) { |
0fff78ff | 1049 | id = xmalloc(sizeof(*id)); |
1050 | memset(id, 0, sizeof(*id)); | |
1051 | id->key = key; | |
1052 | id->filename = comment; | |
1053 | id->ac = ac; | |
1054 | TAILQ_INSERT_TAIL(&agent, id, next); | |
1055 | } | |
1056 | } | |
1057 | /* append remaining agent keys */ | |
1058 | for (id = TAILQ_FIRST(&agent); id; id = TAILQ_FIRST(&agent)) { | |
1059 | TAILQ_REMOVE(&agent, id, next); | |
1060 | TAILQ_INSERT_TAIL(preferred, id, next); | |
1061 | } | |
1062 | authctxt->agent = ac; | |
1063 | } | |
1064 | /* append remaining keys from the config file */ | |
1065 | for (id = TAILQ_FIRST(&files); id; id = TAILQ_FIRST(&files)) { | |
1066 | TAILQ_REMOVE(&files, id, next); | |
1067 | TAILQ_INSERT_TAIL(preferred, id, next); | |
1068 | } | |
1069 | TAILQ_FOREACH(id, preferred, next) { | |
1070 | debug2("key: %s (%p)", id->filename, id->key); | |
1071 | } | |
3c0ef626 | 1072 | } |
1073 | ||
0fff78ff | 1074 | static void |
1075 | pubkey_cleanup(Authctxt *authctxt) | |
3c0ef626 | 1076 | { |
0fff78ff | 1077 | Identity *id; |
1078 | ||
1079 | if (authctxt->agent != NULL) | |
1080 | ssh_close_authentication_connection(authctxt->agent); | |
1081 | for (id = TAILQ_FIRST(&authctxt->keys); id; | |
1082 | id = TAILQ_FIRST(&authctxt->keys)) { | |
1083 | TAILQ_REMOVE(&authctxt->keys, id, next); | |
1084 | if (id->key) | |
1085 | key_free(id->key); | |
1086 | if (id->filename) | |
1087 | xfree(id->filename); | |
1088 | xfree(id); | |
3c0ef626 | 1089 | } |
3c0ef626 | 1090 | } |
1091 | ||
1092 | int | |
1093 | userauth_pubkey(Authctxt *authctxt) | |
1094 | { | |
0fff78ff | 1095 | Identity *id; |
3c0ef626 | 1096 | int sent = 0; |
0fff78ff | 1097 | |
1098 | while ((id = TAILQ_FIRST(&authctxt->keys))) { | |
1099 | if (id->tried++) | |
1100 | return (0); | |
cdd66111 | 1101 | /* move key to the end of the queue */ |
0fff78ff | 1102 | TAILQ_REMOVE(&authctxt->keys, id, next); |
1103 | TAILQ_INSERT_TAIL(&authctxt->keys, id, next); | |
1104 | /* | |
1105 | * send a test message if we have the public key. for | |
1106 | * encrypted keys we cannot do this and have to load the | |
1107 | * private key instead | |
1108 | */ | |
1109 | if (id->key && id->key->type != KEY_RSA1) { | |
1110 | debug("Offering public key: %s", id->filename); | |
1111 | sent = send_pubkey_test(authctxt, id); | |
1112 | } else if (id->key == NULL) { | |
1113 | debug("Trying private key: %s", id->filename); | |
1114 | id->key = load_identity_file(id->filename); | |
1115 | if (id->key != NULL) { | |
1116 | id->isprivate = 1; | |
1117 | sent = sign_and_send_pubkey(authctxt, id); | |
1118 | key_free(id->key); | |
1119 | id->key = NULL; | |
3c0ef626 | 1120 | } |
3c0ef626 | 1121 | } |
0fff78ff | 1122 | if (sent) |
1123 | return (sent); | |
3c0ef626 | 1124 | } |
0fff78ff | 1125 | return (0); |
3c0ef626 | 1126 | } |
1127 | ||
1128 | /* | |
1129 | * Send userauth request message specifying keyboard-interactive method. | |
1130 | */ | |
1131 | int | |
1132 | userauth_kbdint(Authctxt *authctxt) | |
1133 | { | |
1134 | static int attempt = 0; | |
1135 | ||
1136 | if (attempt++ >= options.number_of_password_prompts) | |
1137 | return 0; | |
1138 | /* disable if no SSH2_MSG_USERAUTH_INFO_REQUEST has been seen */ | |
1139 | if (attempt > 1 && !authctxt->info_req_seen) { | |
1140 | debug3("userauth_kbdint: disable: no info_req_seen"); | |
1141 | dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, NULL); | |
1142 | return 0; | |
1143 | } | |
1144 | ||
1145 | debug2("userauth_kbdint"); | |
1146 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
1147 | packet_put_cstring(authctxt->server_user); | |
1148 | packet_put_cstring(authctxt->service); | |
1149 | packet_put_cstring(authctxt->method->name); | |
1150 | packet_put_cstring(""); /* lang */ | |
1151 | packet_put_cstring(options.kbd_interactive_devices ? | |
1152 | options.kbd_interactive_devices : ""); | |
1153 | packet_send(); | |
1154 | ||
1155 | dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, &input_userauth_info_req); | |
1156 | return 1; | |
1157 | } | |
1158 | ||
1159 | /* | |
1160 | * parse INFO_REQUEST, prompt user and send INFO_RESPONSE | |
1161 | */ | |
1162 | void | |
e9a17296 | 1163 | input_userauth_info_req(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 1164 | { |
1165 | Authctxt *authctxt = ctxt; | |
1166 | char *name, *inst, *lang, *prompt, *response; | |
1167 | u_int num_prompts, i; | |
1168 | int echo = 0; | |
1169 | ||
1170 | debug2("input_userauth_info_req"); | |
1171 | ||
1172 | if (authctxt == NULL) | |
1173 | fatal("input_userauth_info_req: no authentication context"); | |
1174 | ||
1175 | authctxt->info_req_seen = 1; | |
1176 | ||
1177 | name = packet_get_string(NULL); | |
1178 | inst = packet_get_string(NULL); | |
1179 | lang = packet_get_string(NULL); | |
1180 | if (strlen(name) > 0) | |
0fff78ff | 1181 | logit("%s", name); |
3c0ef626 | 1182 | if (strlen(inst) > 0) |
0fff78ff | 1183 | logit("%s", inst); |
3c0ef626 | 1184 | xfree(name); |
1185 | xfree(inst); | |
1186 | xfree(lang); | |
1187 | ||
1188 | num_prompts = packet_get_int(); | |
1189 | /* | |
1190 | * Begin to build info response packet based on prompts requested. | |
1191 | * We commit to providing the correct number of responses, so if | |
1192 | * further on we run into a problem that prevents this, we have to | |
1193 | * be sure and clean this up and send a correct error response. | |
1194 | */ | |
1195 | packet_start(SSH2_MSG_USERAUTH_INFO_RESPONSE); | |
1196 | packet_put_int(num_prompts); | |
1197 | ||
1198 | debug2("input_userauth_info_req: num_prompts %d", num_prompts); | |
1199 | for (i = 0; i < num_prompts; i++) { | |
1200 | prompt = packet_get_string(NULL); | |
1201 | echo = packet_get_char(); | |
1202 | ||
1203 | response = read_passphrase(prompt, echo ? RP_ECHO : 0); | |
1204 | ||
1205 | packet_put_cstring(response); | |
1206 | memset(response, 0, strlen(response)); | |
1207 | xfree(response); | |
1208 | xfree(prompt); | |
1209 | } | |
e9a17296 | 1210 | packet_check_eom(); /* done with parsing incoming message. */ |
3c0ef626 | 1211 | |
1212 | packet_add_padding(64); | |
1213 | packet_send(); | |
1214 | } | |
1215 | ||
f5799ae1 | 1216 | static int |
680cee3b | 1217 | ssh_keysign(Key *key, u_char **sigp, u_int *lenp, |
f5799ae1 | 1218 | u_char *data, u_int datalen) |
1219 | { | |
1220 | Buffer b; | |
1221 | struct stat st; | |
1222 | pid_t pid; | |
1223 | int to[2], from[2], status, version = 2; | |
1224 | ||
6a9b3198 | 1225 | debug2("ssh_keysign called"); |
f5799ae1 | 1226 | |
1227 | if (stat(_PATH_SSH_KEY_SIGN, &st) < 0) { | |
1228 | error("ssh_keysign: no installed: %s", strerror(errno)); | |
1229 | return -1; | |
1230 | } | |
1231 | if (fflush(stdout) != 0) | |
1232 | error("ssh_keysign: fflush: %s", strerror(errno)); | |
1233 | if (pipe(to) < 0) { | |
1234 | error("ssh_keysign: pipe: %s", strerror(errno)); | |
1235 | return -1; | |
1236 | } | |
1237 | if (pipe(from) < 0) { | |
1238 | error("ssh_keysign: pipe: %s", strerror(errno)); | |
1239 | return -1; | |
1240 | } | |
1241 | if ((pid = fork()) < 0) { | |
1242 | error("ssh_keysign: fork: %s", strerror(errno)); | |
1243 | return -1; | |
1244 | } | |
1245 | if (pid == 0) { | |
1246 | seteuid(getuid()); | |
1247 | setuid(getuid()); | |
1248 | close(from[0]); | |
1249 | if (dup2(from[1], STDOUT_FILENO) < 0) | |
1250 | fatal("ssh_keysign: dup2: %s", strerror(errno)); | |
1251 | close(to[1]); | |
1252 | if (dup2(to[0], STDIN_FILENO) < 0) | |
1253 | fatal("ssh_keysign: dup2: %s", strerror(errno)); | |
1254 | close(from[1]); | |
1255 | close(to[0]); | |
1256 | execl(_PATH_SSH_KEY_SIGN, _PATH_SSH_KEY_SIGN, (char *) 0); | |
1257 | fatal("ssh_keysign: exec(%s): %s", _PATH_SSH_KEY_SIGN, | |
1258 | strerror(errno)); | |
1259 | } | |
1260 | close(from[1]); | |
1261 | close(to[0]); | |
1262 | ||
1263 | buffer_init(&b); | |
1264 | buffer_put_int(&b, packet_get_connection_in()); /* send # of socket */ | |
1265 | buffer_put_string(&b, data, datalen); | |
cdd66111 | 1266 | if (ssh_msg_send(to[1], version, &b) == -1) |
1267 | fatal("ssh_keysign: couldn't send request"); | |
f5799ae1 | 1268 | |
41b2f314 | 1269 | if (ssh_msg_recv(from[0], &b) < 0) { |
f5799ae1 | 1270 | error("ssh_keysign: no reply"); |
cdd66111 | 1271 | buffer_free(&b); |
f5799ae1 | 1272 | return -1; |
1273 | } | |
1274 | close(from[0]); | |
1275 | close(to[1]); | |
1276 | ||
1277 | while (waitpid(pid, &status, 0) < 0) | |
1278 | if (errno != EINTR) | |
1279 | break; | |
1280 | ||
1281 | if (buffer_get_char(&b) != version) { | |
1282 | error("ssh_keysign: bad version"); | |
cdd66111 | 1283 | buffer_free(&b); |
f5799ae1 | 1284 | return -1; |
1285 | } | |
1286 | *sigp = buffer_get_string(&b, lenp); | |
cdd66111 | 1287 | buffer_free(&b); |
f5799ae1 | 1288 | |
1289 | return 0; | |
1290 | } | |
1291 | ||
3c0ef626 | 1292 | int |
1293 | userauth_hostbased(Authctxt *authctxt) | |
1294 | { | |
1295 | Key *private = NULL; | |
f5799ae1 | 1296 | Sensitive *sensitive = authctxt->sensitive; |
3c0ef626 | 1297 | Buffer b; |
1298 | u_char *signature, *blob; | |
1299 | char *chost, *pkalg, *p; | |
1300 | const char *service; | |
1301 | u_int blen, slen; | |
1302 | int ok, i, len, found = 0; | |
1303 | ||
1304 | /* check for a useful key */ | |
f5799ae1 | 1305 | for (i = 0; i < sensitive->nkeys; i++) { |
1306 | private = sensitive->keys[i]; | |
3c0ef626 | 1307 | if (private && private->type != KEY_RSA1) { |
1308 | found = 1; | |
1309 | /* we take and free the key */ | |
f5799ae1 | 1310 | sensitive->keys[i] = NULL; |
3c0ef626 | 1311 | break; |
1312 | } | |
1313 | } | |
1314 | if (!found) { | |
6a9b3198 | 1315 | debug("No more client hostkeys for hostbased authentication."); |
3c0ef626 | 1316 | return 0; |
1317 | } | |
1318 | if (key_to_blob(private, &blob, &blen) == 0) { | |
1319 | key_free(private); | |
1320 | return 0; | |
1321 | } | |
1322 | /* figure out a name for the client host */ | |
1323 | p = get_local_name(packet_get_connection_in()); | |
1324 | if (p == NULL) { | |
1325 | error("userauth_hostbased: cannot get local ipaddr/name"); | |
1326 | key_free(private); | |
1327 | return 0; | |
1328 | } | |
1329 | len = strlen(p) + 2; | |
1330 | chost = xmalloc(len); | |
1331 | strlcpy(chost, p, len); | |
1332 | strlcat(chost, ".", len); | |
1333 | debug2("userauth_hostbased: chost %s", chost); | |
6a9b3198 | 1334 | xfree(p); |
3c0ef626 | 1335 | |
1336 | service = datafellows & SSH_BUG_HBSERVICE ? "ssh-userauth" : | |
1337 | authctxt->service; | |
1338 | pkalg = xstrdup(key_ssh_name(private)); | |
1339 | buffer_init(&b); | |
1340 | /* construct data */ | |
1341 | buffer_put_string(&b, session_id2, session_id2_len); | |
1342 | buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST); | |
1343 | buffer_put_cstring(&b, authctxt->server_user); | |
1344 | buffer_put_cstring(&b, service); | |
1345 | buffer_put_cstring(&b, authctxt->method->name); | |
1346 | buffer_put_cstring(&b, pkalg); | |
1347 | buffer_put_string(&b, blob, blen); | |
1348 | buffer_put_cstring(&b, chost); | |
1349 | buffer_put_cstring(&b, authctxt->local_user); | |
1350 | #ifdef DEBUG_PK | |
1351 | buffer_dump(&b); | |
1352 | #endif | |
f5799ae1 | 1353 | if (sensitive->external_keysign) |
1354 | ok = ssh_keysign(private, &signature, &slen, | |
1355 | buffer_ptr(&b), buffer_len(&b)); | |
1356 | else | |
1357 | ok = key_sign(private, &signature, &slen, | |
1358 | buffer_ptr(&b), buffer_len(&b)); | |
3c0ef626 | 1359 | key_free(private); |
1360 | buffer_free(&b); | |
1361 | if (ok != 0) { | |
1362 | error("key_sign failed"); | |
1363 | xfree(chost); | |
1364 | xfree(pkalg); | |
1365 | return 0; | |
1366 | } | |
1367 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
1368 | packet_put_cstring(authctxt->server_user); | |
1369 | packet_put_cstring(authctxt->service); | |
1370 | packet_put_cstring(authctxt->method->name); | |
1371 | packet_put_cstring(pkalg); | |
1372 | packet_put_string(blob, blen); | |
1373 | packet_put_cstring(chost); | |
1374 | packet_put_cstring(authctxt->local_user); | |
1375 | packet_put_string(signature, slen); | |
1376 | memset(signature, 's', slen); | |
1377 | xfree(signature); | |
1378 | xfree(chost); | |
1379 | xfree(pkalg); | |
1380 | ||
1381 | packet_send(); | |
1382 | return 1; | |
1383 | } | |
1384 | ||
1385 | /* find auth method */ | |
1386 | ||
1387 | /* | |
1388 | * given auth method name, if configurable options permit this method fill | |
1389 | * in auth_ident field and return true, otherwise return false. | |
1390 | */ | |
1391 | static int | |
1392 | authmethod_is_enabled(Authmethod *method) | |
1393 | { | |
1394 | if (method == NULL) | |
1395 | return 0; | |
1396 | /* return false if options indicate this method is disabled */ | |
1397 | if (method->enabled == NULL || *method->enabled == 0) | |
1398 | return 0; | |
1399 | /* return false if batch mode is enabled but method needs interactive mode */ | |
1400 | if (method->batch_flag != NULL && *method->batch_flag != 0) | |
1401 | return 0; | |
1402 | return 1; | |
1403 | } | |
1404 | ||
1405 | static Authmethod * | |
1406 | authmethod_lookup(const char *name) | |
1407 | { | |
1408 | Authmethod *method = NULL; | |
1409 | if (name != NULL) | |
1410 | for (method = authmethods; method->name != NULL; method++) | |
1411 | if (strcmp(name, method->name) == 0) | |
1412 | return method; | |
1413 | debug2("Unrecognized authentication method name: %s", name ? name : "NULL"); | |
1414 | return NULL; | |
1415 | } | |
1416 | ||
1417 | /* XXX internal state */ | |
1418 | static Authmethod *current = NULL; | |
1419 | static char *supported = NULL; | |
1420 | static char *preferred = NULL; | |
680cee3b | 1421 | |
3c0ef626 | 1422 | /* |
1423 | * Given the authentication method list sent by the server, return the | |
1424 | * next method we should try. If the server initially sends a nil list, | |
1425 | * use a built-in default list. | |
1426 | */ | |
1427 | static Authmethod * | |
1428 | authmethod_get(char *authlist) | |
1429 | { | |
3c0ef626 | 1430 | char *name = NULL; |
e9a17296 | 1431 | u_int next; |
3c0ef626 | 1432 | |
1433 | /* Use a suitable default if we're passed a nil list. */ | |
1434 | if (authlist == NULL || strlen(authlist) == 0) | |
1435 | authlist = options.preferred_authentications; | |
1436 | ||
1437 | if (supported == NULL || strcmp(authlist, supported) != 0) { | |
1438 | debug3("start over, passed a different list %s", authlist); | |
1439 | if (supported != NULL) | |
1440 | xfree(supported); | |
1441 | supported = xstrdup(authlist); | |
1442 | preferred = options.preferred_authentications; | |
1443 | debug3("preferred %s", preferred); | |
1444 | current = NULL; | |
1445 | } else if (current != NULL && authmethod_is_enabled(current)) | |
1446 | return current; | |
1447 | ||
1448 | for (;;) { | |
1449 | if ((name = match_list(preferred, supported, &next)) == NULL) { | |
6a9b3198 | 1450 | debug("No more authentication methods to try."); |
3c0ef626 | 1451 | current = NULL; |
1452 | return NULL; | |
1453 | } | |
1454 | preferred += next; | |
1455 | debug3("authmethod_lookup %s", name); | |
1456 | debug3("remaining preferred: %s", preferred); | |
1457 | if ((current = authmethod_lookup(name)) != NULL && | |
1458 | authmethod_is_enabled(current)) { | |
1459 | debug3("authmethod_is_enabled %s", name); | |
6a9b3198 | 1460 | debug("Next authentication method: %s", name); |
3c0ef626 | 1461 | return current; |
1462 | } | |
1463 | } | |
1464 | } | |
1465 | ||
3c0ef626 | 1466 | static char * |
1467 | authmethods_get(void) | |
1468 | { | |
1469 | Authmethod *method = NULL; | |
e9a17296 | 1470 | Buffer b; |
1471 | char *list; | |
3c0ef626 | 1472 | |
e9a17296 | 1473 | buffer_init(&b); |
3c0ef626 | 1474 | for (method = authmethods; method->name != NULL; method++) { |
1475 | if (authmethod_is_enabled(method)) { | |
e9a17296 | 1476 | if (buffer_len(&b) > 0) |
1477 | buffer_append(&b, ",", 1); | |
1478 | buffer_append(&b, method->name, strlen(method->name)); | |
3c0ef626 | 1479 | } |
1480 | } | |
e9a17296 | 1481 | buffer_append(&b, "\0", 1); |
1482 | list = xstrdup(buffer_ptr(&b)); | |
1483 | buffer_free(&b); | |
1484 | return list; | |
3c0ef626 | 1485 | } |