]>
Commit | Line | Data |
---|---|---|
a306f2dd | 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. | |
a306f2dd | 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" | |
19e633e7 | 26 | RCSID("$OpenBSD: sshconnect2.c,v 1.125 2003/10/07 01:47:27 dtucker Exp $"); |
a306f2dd | 27 | |
751092f9 | 28 | #include "openbsd-compat/sys-queue.h" |
29 | ||
a306f2dd | 30 | #include "ssh.h" |
42f11eb2 | 31 | #include "ssh2.h" |
a306f2dd | 32 | #include "xmalloc.h" |
a306f2dd | 33 | #include "buffer.h" |
34 | #include "packet.h" | |
a306f2dd | 35 | #include "compat.h" |
a306f2dd | 36 | #include "bufaux.h" |
42f11eb2 | 37 | #include "cipher.h" |
a306f2dd | 38 | #include "kex.h" |
39 | #include "myproposal.h" | |
a306f2dd | 40 | #include "sshconnect.h" |
41 | #include "authfile.h" | |
db1cd2f3 | 42 | #include "dh.h" |
2e73a022 | 43 | #include "authfd.h" |
42f11eb2 | 44 | #include "log.h" |
45 | #include "readconf.h" | |
46 | #include "readpass.h" | |
cab80f75 | 47 | #include "match.h" |
a5c9ffdb | 48 | #include "dispatch.h" |
8002af61 | 49 | #include "canohost.h" |
39c00dc2 | 50 | #include "msg.h" |
51 | #include "pathnames.h" | |
94ec8c6b | 52 | |
7364bd04 | 53 | #ifdef GSSAPI |
54 | #include "ssh-gss.h" | |
55 | #endif | |
56 | ||
a306f2dd | 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 | ||
1e3b8b07 | 66 | u_char *session_id2 = NULL; |
a27002e5 | 67 | u_int session_id2_len = 0; |
a306f2dd | 68 | |
a5c9ffdb | 69 | char *xxx_host; |
70 | struct sockaddr *xxx_hostaddr; | |
71 | ||
e092ce67 | 72 | Kex *xxx_kex = NULL; |
73 | ||
396c147e | 74 | static int |
f49bc4f7 | 75 | verify_host_key_callback(Key *hostkey) |
a5c9ffdb | 76 | { |
f49bc4f7 | 77 | if (verify_host_key(xxx_host, xxx_hostaddr, hostkey) == -1) |
01e9ef57 | 78 | fatal("Host key verification failed."); |
a5c9ffdb | 79 | return 0; |
80 | } | |
81 | ||
a306f2dd | 82 | void |
94ec8c6b | 83 | ssh_kex2(char *host, struct sockaddr *hostaddr) |
84 | { | |
94ec8c6b | 85 | Kex *kex; |
a5c9ffdb | 86 | |
87 | xxx_host = host; | |
88 | xxx_hostaddr = hostaddr; | |
94ec8c6b | 89 | |
c523303b | 90 | if (options.ciphers == (char *)-1) { |
bbe88b6d | 91 | logit("No valid ciphers for protocol version 2 given, using defaults."); |
c523303b | 92 | options.ciphers = NULL; |
94ec8c6b | 93 | } |
94 | if (options.ciphers != NULL) { | |
95 | myproposal[PROPOSAL_ENC_ALGS_CTOS] = | |
96 | myproposal[PROPOSAL_ENC_ALGS_STOC] = options.ciphers; | |
97 | } | |
1ad64a93 | 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]); | |
94ec8c6b | 102 | if (options.compression) { |
b2552997 | 103 | myproposal[PROPOSAL_COMP_ALGS_CTOS] = |
713f6cd9 | 104 | myproposal[PROPOSAL_COMP_ALGS_STOC] = "zlib,none"; |
94ec8c6b | 105 | } else { |
b2552997 | 106 | myproposal[PROPOSAL_COMP_ALGS_CTOS] = |
713f6cd9 | 107 | myproposal[PROPOSAL_COMP_ALGS_STOC] = "none,zlib"; |
94ec8c6b | 108 | } |
b2552997 | 109 | if (options.macs != NULL) { |
110 | myproposal[PROPOSAL_MAC_ALGS_CTOS] = | |
111 | myproposal[PROPOSAL_MAC_ALGS_STOC] = options.macs; | |
112 | } | |
e961a8f9 | 113 | if (options.hostkeyalgorithms != NULL) |
184eed6a | 114 | myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = |
e961a8f9 | 115 | options.hostkeyalgorithms; |
94ec8c6b | 116 | |
ffd7b36b | 117 | if (options.rekey_limit) |
118 | packet_set_rekey_limit(options.rekey_limit); | |
119 | ||
7a37c112 | 120 | /* start key exchange */ |
d8ee838b | 121 | kex = kex_setup(myproposal); |
98a58eda | 122 | kex->kex[KEX_DH_GRP1_SHA1] = kexdh_client; |
123 | kex->kex[KEX_DH_GEX_SHA1] = kexgex_client; | |
a5c9ffdb | 124 | kex->client_version_string=client_version_string; |
125 | kex->server_version_string=server_version_string; | |
f49bc4f7 | 126 | kex->verify_host_key=&verify_host_key_callback; |
94ec8c6b | 127 | |
e092ce67 | 128 | xxx_kex = kex; |
129 | ||
c422989b | 130 | dispatch_run(DISPATCH_BLOCK, &kex->done, kex); |
94ec8c6b | 131 | |
d1ac6175 | 132 | session_id2 = kex->session_id; |
133 | session_id2_len = kex->session_id_len; | |
134 | ||
94ec8c6b | 135 | #ifdef DEBUG_KEXDH |
136 | /* send 1st encrypted/maced/compressed message */ | |
137 | packet_start(SSH2_MSG_IGNORE); | |
138 | packet_put_cstring("markus"); | |
139 | packet_send(); | |
140 | packet_write_wait(); | |
141 | #endif | |
a306f2dd | 142 | } |
71276795 | 143 | |
a306f2dd | 144 | /* |
145 | * Authenticate user | |
146 | */ | |
188adeb2 | 147 | |
148 | typedef struct Authctxt Authctxt; | |
149 | typedef struct Authmethod Authmethod; | |
43348518 | 150 | typedef struct identity Identity; |
151 | typedef struct idlist Idlist; | |
152 | ||
153 | struct identity { | |
154 | TAILQ_ENTRY(identity) next; | |
155 | AuthenticationConnection *ac; /* set if agent supports key */ | |
156 | Key *key; /* public/private key */ | |
157 | char *filename; /* comment for agent-only keys */ | |
158 | int tried; | |
159 | int isprivate; /* key points to the private key */ | |
160 | }; | |
161 | TAILQ_HEAD(idlist, identity); | |
188adeb2 | 162 | |
163 | struct Authctxt { | |
164 | const char *server_user; | |
8002af61 | 165 | const char *local_user; |
188adeb2 | 166 | const char *host; |
167 | const char *service; | |
188adeb2 | 168 | Authmethod *method; |
94ec8c6b | 169 | int success; |
fee56204 | 170 | char *authlist; |
8002af61 | 171 | /* pubkey */ |
43348518 | 172 | Idlist keys; |
8002af61 | 173 | AuthenticationConnection *agent; |
174 | /* hostbased */ | |
39c00dc2 | 175 | Sensitive *sensitive; |
6b759005 | 176 | /* kbd-interactive */ |
177 | int info_req_seen; | |
7364bd04 | 178 | /* generic */ |
179 | void *methoddata; | |
188adeb2 | 180 | }; |
181 | struct Authmethod { | |
182 | char *name; /* string to compare against server's list */ | |
183 | int (*userauth)(Authctxt *authctxt); | |
184 | int *enabled; /* flag in option struct that enables method */ | |
185 | int *batch_flag; /* flag in option struct that disables method */ | |
186 | }; | |
187 | ||
7819b5c3 | 188 | void input_userauth_success(int, u_int32_t, void *); |
189 | void input_userauth_failure(int, u_int32_t, void *); | |
190 | void input_userauth_banner(int, u_int32_t, void *); | |
191 | void input_userauth_error(int, u_int32_t, void *); | |
192 | void input_userauth_info_req(int, u_int32_t, void *); | |
193 | void input_userauth_pk_ok(int, u_int32_t, void *); | |
67ec167d | 194 | void input_userauth_passwd_changereq(int, u_int32_t, void *); |
94ec8c6b | 195 | |
d5bb9418 | 196 | int userauth_none(Authctxt *); |
197 | int userauth_pubkey(Authctxt *); | |
198 | int userauth_passwd(Authctxt *); | |
199 | int userauth_kbdint(Authctxt *); | |
200 | int userauth_hostbased(Authctxt *); | |
802e01b8 | 201 | int userauth_kerberos(Authctxt *); |
188adeb2 | 202 | |
7364bd04 | 203 | #ifdef GSSAPI |
204 | int userauth_gssapi(Authctxt *authctxt); | |
205 | void input_gssapi_response(int type, u_int32_t, void *); | |
206 | void input_gssapi_token(int type, u_int32_t, void *); | |
207 | void input_gssapi_hash(int type, u_int32_t, void *); | |
208 | void input_gssapi_error(int, u_int32_t, void *); | |
209 | void input_gssapi_errtok(int, u_int32_t, void *); | |
210 | #endif | |
211 | ||
d5bb9418 | 212 | void userauth(Authctxt *, char *); |
fee56204 | 213 | |
43348518 | 214 | static int sign_and_send_pubkey(Authctxt *, Identity *); |
43348518 | 215 | static void pubkey_prepare(Authctxt *); |
216 | static void pubkey_cleanup(Authctxt *); | |
217 | static Key *load_identity_file(char *); | |
fee56204 | 218 | |
396c147e | 219 | static Authmethod *authmethod_get(char *authlist); |
220 | static Authmethod *authmethod_lookup(const char *name); | |
221 | static char *authmethods_get(void); | |
188adeb2 | 222 | |
223 | Authmethod authmethods[] = { | |
7364bd04 | 224 | #ifdef GSSAPI |
225 | {"gssapi", | |
226 | userauth_gssapi, | |
227 | &options.gss_authentication, | |
228 | NULL}, | |
229 | #endif | |
3398dda9 | 230 | {"hostbased", |
231 | userauth_hostbased, | |
232 | &options.hostbased_authentication, | |
233 | NULL}, | |
9f37c0af | 234 | {"publickey", |
235 | userauth_pubkey, | |
236 | &options.pubkey_authentication, | |
237 | NULL}, | |
94ec8c6b | 238 | {"keyboard-interactive", |
239 | userauth_kbdint, | |
240 | &options.kbd_interactive_authentication, | |
241 | &options.batch_mode}, | |
9f37c0af | 242 | {"password", |
243 | userauth_passwd, | |
244 | &options.password_authentication, | |
245 | &options.batch_mode}, | |
94ec8c6b | 246 | {"none", |
247 | userauth_none, | |
248 | NULL, | |
249 | NULL}, | |
188adeb2 | 250 | {NULL, NULL, NULL, NULL} |
251 | }; | |
252 | ||
253 | void | |
8002af61 | 254 | ssh_userauth2(const char *local_user, const char *server_user, char *host, |
39c00dc2 | 255 | Sensitive *sensitive) |
188adeb2 | 256 | { |
257 | Authctxt authctxt; | |
258 | int type; | |
188adeb2 | 259 | |
5ba55ada | 260 | if (options.challenge_response_authentication) |
d464095c | 261 | options.kbd_interactive_authentication = 1; |
262 | ||
188adeb2 | 263 | packet_start(SSH2_MSG_SERVICE_REQUEST); |
264 | packet_put_cstring("ssh-userauth"); | |
265 | packet_send(); | |
a77673cc | 266 | debug("SSH2_MSG_SERVICE_REQUEST sent"); |
188adeb2 | 267 | packet_write_wait(); |
54a5250f | 268 | type = packet_read(); |
a77673cc | 269 | if (type != SSH2_MSG_SERVICE_ACCEPT) |
270 | fatal("Server denied authentication request: %d", type); | |
188adeb2 | 271 | if (packet_remaining() > 0) { |
54a5250f | 272 | char *reply = packet_get_string(NULL); |
a77673cc | 273 | debug2("service_accept: %s", reply); |
188adeb2 | 274 | xfree(reply); |
188adeb2 | 275 | } else { |
6226a8f8 | 276 | debug2("buggy server: service_accept w/o service"); |
188adeb2 | 277 | } |
95500969 | 278 | packet_check_eom(); |
a77673cc | 279 | debug("SSH2_MSG_SERVICE_ACCEPT received"); |
188adeb2 | 280 | |
cab80f75 | 281 | if (options.preferred_authentications == NULL) |
282 | options.preferred_authentications = authmethods_get(); | |
283 | ||
188adeb2 | 284 | /* setup authentication context */ |
6b759005 | 285 | memset(&authctxt, 0, sizeof(authctxt)); |
43348518 | 286 | pubkey_prepare(&authctxt); |
188adeb2 | 287 | authctxt.server_user = server_user; |
8002af61 | 288 | authctxt.local_user = local_user; |
188adeb2 | 289 | authctxt.host = host; |
290 | authctxt.service = "ssh-connection"; /* service name */ | |
291 | authctxt.success = 0; | |
94ec8c6b | 292 | authctxt.method = authmethod_lookup("none"); |
fee56204 | 293 | authctxt.authlist = NULL; |
7364bd04 | 294 | authctxt.methoddata = NULL; |
39c00dc2 | 295 | authctxt.sensitive = sensitive; |
6b759005 | 296 | authctxt.info_req_seen = 0; |
94ec8c6b | 297 | if (authctxt.method == NULL) |
298 | fatal("ssh_userauth2: internal error: cannot send userauth none request"); | |
188adeb2 | 299 | |
300 | /* initial userauth request */ | |
94ec8c6b | 301 | userauth_none(&authctxt); |
188adeb2 | 302 | |
7a37c112 | 303 | dispatch_init(&input_userauth_error); |
188adeb2 | 304 | dispatch_set(SSH2_MSG_USERAUTH_SUCCESS, &input_userauth_success); |
305 | dispatch_set(SSH2_MSG_USERAUTH_FAILURE, &input_userauth_failure); | |
9616313f | 306 | dispatch_set(SSH2_MSG_USERAUTH_BANNER, &input_userauth_banner); |
188adeb2 | 307 | dispatch_run(DISPATCH_BLOCK, &authctxt.success, &authctxt); /* loop until success */ |
308 | ||
43348518 | 309 | pubkey_cleanup(&authctxt); |
b8c2031b | 310 | dispatch_range(SSH2_MSG_USERAUTH_MIN, SSH2_MSG_USERAUTH_MAX, NULL); |
311 | ||
6226a8f8 | 312 | debug("Authentication succeeded (%s).", authctxt.method->name); |
188adeb2 | 313 | } |
b8c2031b | 314 | |
188adeb2 | 315 | void |
fee56204 | 316 | userauth(Authctxt *authctxt, char *authlist) |
317 | { | |
7364bd04 | 318 | if (authctxt->methoddata) { |
319 | xfree(authctxt->methoddata); | |
320 | authctxt->methoddata = NULL; | |
321 | } | |
fee56204 | 322 | if (authlist == NULL) { |
323 | authlist = authctxt->authlist; | |
324 | } else { | |
325 | if (authctxt->authlist) | |
326 | xfree(authctxt->authlist); | |
327 | authctxt->authlist = authlist; | |
328 | } | |
329 | for (;;) { | |
330 | Authmethod *method = authmethod_get(authlist); | |
331 | if (method == NULL) | |
332 | fatal("Permission denied (%s).", authlist); | |
333 | authctxt->method = method; | |
b8c2031b | 334 | |
335 | /* reset the per method handler */ | |
336 | dispatch_range(SSH2_MSG_USERAUTH_PER_METHOD_MIN, | |
337 | SSH2_MSG_USERAUTH_PER_METHOD_MAX, NULL); | |
338 | ||
339 | /* and try new method */ | |
fee56204 | 340 | if (method->userauth(authctxt) != 0) { |
341 | debug2("we sent a %s packet, wait for reply", method->name); | |
342 | break; | |
343 | } else { | |
344 | debug2("we did not send a packet, disable method"); | |
345 | method->enabled = NULL; | |
346 | } | |
347 | } | |
348 | } | |
d6133f43 | 349 | |
fee56204 | 350 | void |
7819b5c3 | 351 | input_userauth_error(int type, u_int32_t seq, void *ctxt) |
188adeb2 | 352 | { |
9616313f | 353 | fatal("input_userauth_error: bad message during authentication: " |
354 | "type %d", type); | |
355 | } | |
d6133f43 | 356 | |
9616313f | 357 | void |
7819b5c3 | 358 | input_userauth_banner(int type, u_int32_t seq, void *ctxt) |
9616313f | 359 | { |
360 | char *msg, *lang; | |
361 | debug3("input_userauth_banner"); | |
362 | msg = packet_get_string(NULL); | |
363 | lang = packet_get_string(NULL); | |
19e633e7 | 364 | if (options.log_level > SYSLOG_LEVEL_QUIET) |
365 | fprintf(stderr, "%s", msg); | |
9616313f | 366 | xfree(msg); |
367 | xfree(lang); | |
188adeb2 | 368 | } |
d6133f43 | 369 | |
188adeb2 | 370 | void |
7819b5c3 | 371 | input_userauth_success(int type, u_int32_t seq, void *ctxt) |
188adeb2 | 372 | { |
373 | Authctxt *authctxt = ctxt; | |
374 | if (authctxt == NULL) | |
375 | fatal("input_userauth_success: no authentication context"); | |
fee56204 | 376 | if (authctxt->authlist) |
377 | xfree(authctxt->authlist); | |
7364bd04 | 378 | if (authctxt->methoddata) |
379 | xfree(authctxt->methoddata); | |
188adeb2 | 380 | authctxt->success = 1; /* break out */ |
381 | } | |
d6133f43 | 382 | |
188adeb2 | 383 | void |
7819b5c3 | 384 | input_userauth_failure(int type, u_int32_t seq, void *ctxt) |
188adeb2 | 385 | { |
188adeb2 | 386 | Authctxt *authctxt = ctxt; |
387 | char *authlist = NULL; | |
388 | int partial; | |
188adeb2 | 389 | |
390 | if (authctxt == NULL) | |
391 | fatal("input_userauth_failure: no authentication context"); | |
392 | ||
94ec8c6b | 393 | authlist = packet_get_string(NULL); |
188adeb2 | 394 | partial = packet_get_char(); |
95500969 | 395 | packet_check_eom(); |
188adeb2 | 396 | |
397 | if (partial != 0) | |
bbe88b6d | 398 | logit("Authenticated with partial success."); |
6226a8f8 | 399 | debug("Authentications that can continue: %s", authlist); |
188adeb2 | 400 | |
fee56204 | 401 | userauth(authctxt, authlist); |
402 | } | |
403 | void | |
7819b5c3 | 404 | input_userauth_pk_ok(int type, u_int32_t seq, void *ctxt) |
fee56204 | 405 | { |
406 | Authctxt *authctxt = ctxt; | |
407 | Key *key = NULL; | |
43348518 | 408 | Identity *id = NULL; |
fee56204 | 409 | Buffer b; |
c66f9d0e | 410 | int pktype, sent = 0; |
411 | u_int alen, blen; | |
412 | char *pkalg, *fp; | |
413 | u_char *pkblob; | |
fee56204 | 414 | |
415 | if (authctxt == NULL) | |
416 | fatal("input_userauth_pk_ok: no authentication context"); | |
417 | if (datafellows & SSH_BUG_PKOK) { | |
418 | /* this is similar to SSH_BUG_PKAUTH */ | |
419 | debug2("input_userauth_pk_ok: SSH_BUG_PKOK"); | |
420 | pkblob = packet_get_string(&blen); | |
421 | buffer_init(&b); | |
422 | buffer_append(&b, pkblob, blen); | |
423 | pkalg = buffer_get_string(&b, &alen); | |
424 | buffer_free(&b); | |
425 | } else { | |
426 | pkalg = packet_get_string(&alen); | |
427 | pkblob = packet_get_string(&blen); | |
428 | } | |
95500969 | 429 | packet_check_eom(); |
fee56204 | 430 | |
43348518 | 431 | debug("Server accepts key: pkalg %s blen %u", pkalg, blen); |
fee56204 | 432 | |
43348518 | 433 | if ((pktype = key_type_from_name(pkalg)) == KEY_UNSPEC) { |
434 | debug("unknown pkalg %s", pkalg); | |
435 | goto done; | |
436 | } | |
437 | if ((key = key_from_blob(pkblob, blen)) == NULL) { | |
438 | debug("no key from blob. pkalg %s", pkalg); | |
439 | goto done; | |
440 | } | |
441 | if (key->type != pktype) { | |
442 | error("input_userauth_pk_ok: type mismatch " | |
443 | "for decoded key (received %d, expected %d)", | |
444 | key->type, pktype); | |
445 | goto done; | |
446 | } | |
447 | fp = key_fingerprint(key, SSH_FP_MD5, SSH_FP_HEX); | |
448 | debug2("input_userauth_pk_ok: fp %s", fp); | |
449 | xfree(fp); | |
450 | ||
451 | TAILQ_FOREACH(id, &authctxt->keys, next) { | |
452 | if (key_equal(key, id->key)) { | |
453 | sent = sign_and_send_pubkey(authctxt, id); | |
fee56204 | 454 | break; |
455 | } | |
43348518 | 456 | } |
457 | done: | |
fee56204 | 458 | if (key != NULL) |
459 | key_free(key); | |
460 | xfree(pkalg); | |
461 | xfree(pkblob); | |
462 | ||
343288b8 | 463 | /* try another method if we did not send a packet */ |
fee56204 | 464 | if (sent == 0) |
465 | userauth(authctxt, NULL); | |
188adeb2 | 466 | } |
467 | ||
7364bd04 | 468 | #ifdef GSSAPI |
469 | int | |
470 | userauth_gssapi(Authctxt *authctxt) | |
471 | { | |
472 | Gssctxt *gssctxt = NULL; | |
473 | static gss_OID_set supported = NULL; | |
474 | static int mech = 0; | |
475 | OM_uint32 min; | |
476 | int ok = 0; | |
477 | ||
478 | /* Try one GSSAPI method at a time, rather than sending them all at | |
479 | * once. */ | |
480 | ||
481 | if (supported == NULL) | |
482 | gss_indicate_mechs(&min, &supported); | |
483 | ||
484 | /* Check to see if the mechanism is usable before we offer it */ | |
485 | while (mech<supported->count && !ok) { | |
486 | if (gssctxt) | |
487 | ssh_gssapi_delete_ctx(&gssctxt); | |
488 | ssh_gssapi_build_ctx(&gssctxt); | |
489 | ssh_gssapi_set_oid(gssctxt, &supported->elements[mech]); | |
490 | ||
491 | /* My DER encoding requires length<128 */ | |
492 | if (supported->elements[mech].length < 128 && | |
493 | !GSS_ERROR(ssh_gssapi_import_name(gssctxt, | |
494 | authctxt->host))) { | |
495 | ok = 1; /* Mechanism works */ | |
496 | } else { | |
497 | mech++; | |
498 | } | |
499 | } | |
500 | ||
501 | if (!ok) return 0; | |
502 | ||
503 | authctxt->methoddata=(void *)gssctxt; | |
504 | ||
505 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
506 | packet_put_cstring(authctxt->server_user); | |
507 | packet_put_cstring(authctxt->service); | |
508 | packet_put_cstring(authctxt->method->name); | |
509 | ||
510 | packet_put_int(1); | |
511 | ||
512 | /* Some servers encode the OID incorrectly (as we used to) */ | |
513 | if (datafellows & SSH_BUG_GSSAPI_BER) { | |
514 | packet_put_string(supported->elements[mech].elements, | |
515 | supported->elements[mech].length); | |
516 | } else { | |
517 | packet_put_int((supported->elements[mech].length)+2); | |
518 | packet_put_char(SSH_GSS_OIDTYPE); | |
519 | packet_put_char(supported->elements[mech].length); | |
520 | packet_put_raw(supported->elements[mech].elements, | |
521 | supported->elements[mech].length); | |
522 | } | |
523 | ||
524 | packet_send(); | |
525 | ||
526 | dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE, &input_gssapi_response); | |
527 | dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, &input_gssapi_token); | |
528 | dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERROR, &input_gssapi_error); | |
529 | dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, &input_gssapi_errtok); | |
530 | ||
531 | mech++; /* Move along to next candidate */ | |
532 | ||
533 | return 1; | |
534 | } | |
535 | ||
536 | void | |
537 | input_gssapi_response(int type, u_int32_t plen, void *ctxt) | |
538 | { | |
539 | Authctxt *authctxt = ctxt; | |
540 | Gssctxt *gssctxt; | |
541 | OM_uint32 status, ms; | |
542 | int oidlen; | |
543 | char *oidv; | |
544 | gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER; | |
545 | ||
546 | if (authctxt == NULL) | |
547 | fatal("input_gssapi_response: no authentication context"); | |
548 | gssctxt = authctxt->methoddata; | |
549 | ||
550 | /* Setup our OID */ | |
551 | oidv = packet_get_string(&oidlen); | |
552 | ||
553 | if (datafellows & SSH_BUG_GSSAPI_BER) { | |
554 | if (!ssh_gssapi_check_oid(gssctxt, oidv, oidlen)) | |
555 | fatal("Server returned different OID than expected"); | |
556 | } else { | |
557 | if(oidv[0] != SSH_GSS_OIDTYPE || oidv[1] != oidlen-2) { | |
558 | debug("Badly encoded mechanism OID received"); | |
559 | userauth(authctxt, NULL); | |
560 | xfree(oidv); | |
561 | return; | |
562 | } | |
563 | if (!ssh_gssapi_check_oid(gssctxt, oidv+2, oidlen-2)) | |
564 | fatal("Server returned different OID than expected"); | |
565 | } | |
566 | ||
567 | packet_check_eom(); | |
568 | ||
569 | xfree(oidv); | |
570 | ||
571 | status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds, | |
572 | GSS_C_NO_BUFFER, &send_tok, NULL); | |
573 | if (GSS_ERROR(status)) { | |
574 | if (send_tok.length > 0) { | |
575 | packet_start(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK); | |
576 | packet_put_string(send_tok.value, send_tok.length); | |
577 | packet_send(); | |
578 | gss_release_buffer(&ms, &send_tok); | |
579 | } | |
580 | /* Start again with next method on list */ | |
581 | debug("Trying to start again"); | |
582 | userauth(authctxt, NULL); | |
583 | return; | |
584 | } | |
585 | ||
586 | /* We must have data to send */ | |
587 | packet_start(SSH2_MSG_USERAUTH_GSSAPI_TOKEN); | |
588 | packet_put_string(send_tok.value, send_tok.length); | |
589 | packet_send(); | |
590 | gss_release_buffer(&ms, &send_tok); | |
591 | } | |
592 | ||
593 | void | |
594 | input_gssapi_token(int type, u_int32_t plen, void *ctxt) | |
595 | { | |
596 | Authctxt *authctxt = ctxt; | |
597 | Gssctxt *gssctxt; | |
598 | gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER; | |
599 | gss_buffer_desc recv_tok; | |
600 | OM_uint32 status, ms; | |
601 | u_int slen; | |
602 | ||
603 | if (authctxt == NULL) | |
604 | fatal("input_gssapi_response: no authentication context"); | |
605 | gssctxt = authctxt->methoddata; | |
606 | ||
607 | recv_tok.value = packet_get_string(&slen); | |
608 | recv_tok.length = slen; /* safe typecast */ | |
609 | ||
610 | packet_check_eom(); | |
611 | ||
612 | status=ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds, | |
613 | &recv_tok, &send_tok, NULL); | |
614 | ||
615 | xfree(recv_tok.value); | |
616 | ||
617 | if (GSS_ERROR(status)) { | |
618 | if (send_tok.length > 0) { | |
619 | packet_start(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK); | |
620 | packet_put_string(send_tok.value, send_tok.length); | |
621 | packet_send(); | |
622 | gss_release_buffer(&ms, &send_tok); | |
623 | } | |
624 | /* Start again with the next method in the list */ | |
625 | userauth(authctxt, NULL); | |
626 | return; | |
627 | } | |
628 | ||
629 | if (send_tok.length > 0) { | |
630 | packet_start(SSH2_MSG_USERAUTH_GSSAPI_TOKEN); | |
631 | packet_put_string(send_tok.value, send_tok.length); | |
632 | packet_send(); | |
633 | gss_release_buffer(&ms, &send_tok); | |
634 | } | |
635 | ||
636 | if (status == GSS_S_COMPLETE) { | |
637 | /* If that succeeded, send a exchange complete message */ | |
638 | packet_start(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE); | |
639 | packet_send(); | |
640 | } | |
641 | } | |
642 | ||
643 | void | |
644 | input_gssapi_errtok(int type, u_int32_t plen, void *ctxt) | |
645 | { | |
646 | Authctxt *authctxt = ctxt; | |
647 | Gssctxt *gssctxt; | |
648 | gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER; | |
649 | gss_buffer_desc recv_tok; | |
650 | OM_uint32 status, ms; | |
f99e1ca4 | 651 | u_int len; |
7364bd04 | 652 | |
653 | if (authctxt == NULL) | |
654 | fatal("input_gssapi_response: no authentication context"); | |
655 | gssctxt = authctxt->methoddata; | |
656 | ||
f99e1ca4 | 657 | recv_tok.value = packet_get_string(&len); |
658 | recv_tok.length = len; | |
7364bd04 | 659 | |
660 | packet_check_eom(); | |
661 | ||
662 | /* Stick it into GSSAPI and see what it says */ | |
663 | status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds, | |
664 | &recv_tok, &send_tok, NULL); | |
665 | ||
666 | xfree(recv_tok.value); | |
667 | gss_release_buffer(&ms, &send_tok); | |
668 | ||
669 | /* Server will be returning a failed packet after this one */ | |
670 | } | |
671 | ||
672 | void | |
673 | input_gssapi_error(int type, u_int32_t plen, void *ctxt) | |
674 | { | |
675 | OM_uint32 maj, min; | |
676 | char *msg; | |
677 | char *lang; | |
678 | ||
679 | maj=packet_get_int(); | |
680 | min=packet_get_int(); | |
681 | msg=packet_get_string(NULL); | |
682 | lang=packet_get_string(NULL); | |
683 | ||
684 | packet_check_eom(); | |
685 | ||
686 | debug("Server GSSAPI Error:\n%s\n", msg); | |
687 | xfree(msg); | |
688 | xfree(lang); | |
689 | } | |
690 | #endif /* GSSAPI */ | |
691 | ||
94ec8c6b | 692 | int |
693 | userauth_none(Authctxt *authctxt) | |
694 | { | |
695 | /* initial userauth request */ | |
696 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
697 | packet_put_cstring(authctxt->server_user); | |
698 | packet_put_cstring(authctxt->service); | |
699 | packet_put_cstring(authctxt->method->name); | |
700 | packet_send(); | |
94ec8c6b | 701 | return 1; |
702 | } | |
703 | ||
a306f2dd | 704 | int |
188adeb2 | 705 | userauth_passwd(Authctxt *authctxt) |
a306f2dd | 706 | { |
1d1ffb87 | 707 | static int attempt = 0; |
67ec167d | 708 | char prompt[150]; |
a306f2dd | 709 | char *password; |
710 | ||
fa649821 | 711 | if (attempt++ >= options.number_of_password_prompts) |
1d1ffb87 | 712 | return 0; |
713 | ||
6aacefa7 | 714 | if (attempt != 1) |
fa649821 | 715 | error("Permission denied, please try again."); |
716 | ||
f72e01a5 | 717 | snprintf(prompt, sizeof(prompt), "%.30s@%.128s's password: ", |
188adeb2 | 718 | authctxt->server_user, authctxt->host); |
a306f2dd | 719 | password = read_passphrase(prompt, 0); |
720 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
188adeb2 | 721 | packet_put_cstring(authctxt->server_user); |
722 | packet_put_cstring(authctxt->service); | |
94ec8c6b | 723 | packet_put_cstring(authctxt->method->name); |
a306f2dd | 724 | packet_put_char(0); |
a6215e53 | 725 | packet_put_cstring(password); |
a306f2dd | 726 | memset(password, 0, strlen(password)); |
727 | xfree(password); | |
b4b701be | 728 | packet_add_padding(64); |
a306f2dd | 729 | packet_send(); |
67ec167d | 730 | |
7203d6bb | 731 | dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, |
67ec167d | 732 | &input_userauth_passwd_changereq); |
733 | ||
a306f2dd | 734 | return 1; |
735 | } | |
67ec167d | 736 | /* |
737 | * parse PASSWD_CHANGEREQ, prompt user and send SSH2_MSG_USERAUTH_REQUEST | |
738 | */ | |
739 | void | |
ef077e37 | 740 | input_userauth_passwd_changereq(int type, u_int32_t seqnr, void *ctxt) |
67ec167d | 741 | { |
742 | Authctxt *authctxt = ctxt; | |
743 | char *info, *lang, *password = NULL, *retype = NULL; | |
744 | char prompt[150]; | |
745 | ||
746 | debug2("input_userauth_passwd_changereq"); | |
747 | ||
748 | if (authctxt == NULL) | |
749 | fatal("input_userauth_passwd_changereq: " | |
750 | "no authentication context"); | |
751 | ||
752 | info = packet_get_string(NULL); | |
753 | lang = packet_get_string(NULL); | |
754 | if (strlen(info) > 0) | |
bbe88b6d | 755 | logit("%s", info); |
67ec167d | 756 | xfree(info); |
757 | xfree(lang); | |
758 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
759 | packet_put_cstring(authctxt->server_user); | |
760 | packet_put_cstring(authctxt->service); | |
761 | packet_put_cstring(authctxt->method->name); | |
762 | packet_put_char(1); /* additional info */ | |
7203d6bb | 763 | snprintf(prompt, sizeof(prompt), |
67ec167d | 764 | "Enter %.30s@%.128s's old password: ", |
765 | authctxt->server_user, authctxt->host); | |
766 | password = read_passphrase(prompt, 0); | |
767 | packet_put_cstring(password); | |
768 | memset(password, 0, strlen(password)); | |
769 | xfree(password); | |
770 | password = NULL; | |
771 | while (password == NULL) { | |
7203d6bb | 772 | snprintf(prompt, sizeof(prompt), |
67ec167d | 773 | "Enter %.30s@%.128s's new password: ", |
774 | authctxt->server_user, authctxt->host); | |
775 | password = read_passphrase(prompt, RP_ALLOW_EOF); | |
776 | if (password == NULL) { | |
777 | /* bail out */ | |
778 | return; | |
779 | } | |
7203d6bb | 780 | snprintf(prompt, sizeof(prompt), |
67ec167d | 781 | "Retype %.30s@%.128s's new password: ", |
782 | authctxt->server_user, authctxt->host); | |
783 | retype = read_passphrase(prompt, 0); | |
784 | if (strcmp(password, retype) != 0) { | |
785 | memset(password, 0, strlen(password)); | |
786 | xfree(password); | |
bbe88b6d | 787 | logit("Mismatch; try again, EOF to quit."); |
67ec167d | 788 | password = NULL; |
789 | } | |
790 | memset(retype, 0, strlen(retype)); | |
791 | xfree(retype); | |
792 | } | |
793 | packet_put_cstring(password); | |
794 | memset(password, 0, strlen(password)); | |
795 | xfree(password); | |
796 | packet_add_padding(64); | |
797 | packet_send(); | |
7203d6bb | 798 | |
799 | dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, | |
67ec167d | 800 | &input_userauth_passwd_changereq); |
801 | } | |
a306f2dd | 802 | |
43348518 | 803 | static int |
804 | identity_sign(Identity *id, u_char **sigp, u_int *lenp, | |
805 | u_char *data, u_int datalen) | |
806 | { | |
807 | Key *prv; | |
808 | int ret; | |
809 | ||
810 | /* the agent supports this key */ | |
811 | if (id->ac) | |
812 | return (ssh_agent_sign(id->ac, id->key, sigp, lenp, | |
813 | data, datalen)); | |
814 | /* | |
815 | * we have already loaded the private key or | |
816 | * the private key is stored in external hardware | |
817 | */ | |
818 | if (id->isprivate || (id->key->flags & KEY_FLAG_EXT)) | |
819 | return (key_sign(id->key, sigp, lenp, data, datalen)); | |
820 | /* load the private key from the file */ | |
821 | if ((prv = load_identity_file(id->filename)) == NULL) | |
822 | return (-1); | |
823 | ret = key_sign(prv, sigp, lenp, data, datalen); | |
824 | key_free(prv); | |
825 | return (ret); | |
fee56204 | 826 | } |
827 | ||
396c147e | 828 | static int |
43348518 | 829 | sign_and_send_pubkey(Authctxt *authctxt, Identity *id) |
a306f2dd | 830 | { |
831 | Buffer b; | |
1e3b8b07 | 832 | u_char *blob, *signature; |
c66f9d0e | 833 | u_int bloblen, slen; |
a27002e5 | 834 | u_int skip = 0; |
2e73a022 | 835 | int ret = -1; |
94ec8c6b | 836 | int have_sig = 1; |
a306f2dd | 837 | |
cbc5abf9 | 838 | debug3("sign_and_send_pubkey"); |
fee56204 | 839 | |
43348518 | 840 | if (key_to_blob(id->key, &blob, &bloblen) == 0) { |
fa08c86b | 841 | /* we cannot handle this key */ |
cbc5abf9 | 842 | debug3("sign_and_send_pubkey: cannot handle key"); |
fa08c86b | 843 | return 0; |
844 | } | |
a306f2dd | 845 | /* data to be signed */ |
846 | buffer_init(&b); | |
33de75a3 | 847 | if (datafellows & SSH_OLD_SESSIONID) { |
74fc9186 | 848 | buffer_append(&b, session_id2, session_id2_len); |
2b87da3b | 849 | skip = session_id2_len; |
33de75a3 | 850 | } else { |
851 | buffer_put_string(&b, session_id2, session_id2_len); | |
852 | skip = buffer_len(&b); | |
74fc9186 | 853 | } |
a306f2dd | 854 | buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST); |
188adeb2 | 855 | buffer_put_cstring(&b, authctxt->server_user); |
d0c832f3 | 856 | buffer_put_cstring(&b, |
cbc5abf9 | 857 | datafellows & SSH_BUG_PKSERVICE ? |
d0c832f3 | 858 | "ssh-userauth" : |
188adeb2 | 859 | authctxt->service); |
cbc5abf9 | 860 | if (datafellows & SSH_BUG_PKAUTH) { |
861 | buffer_put_char(&b, have_sig); | |
862 | } else { | |
863 | buffer_put_cstring(&b, authctxt->method->name); | |
864 | buffer_put_char(&b, have_sig); | |
43348518 | 865 | buffer_put_cstring(&b, key_ssh_name(id->key)); |
cbc5abf9 | 866 | } |
a306f2dd | 867 | buffer_put_string(&b, blob, bloblen); |
a306f2dd | 868 | |
869 | /* generate signature */ | |
43348518 | 870 | ret = identity_sign(id, &signature, &slen, |
fee56204 | 871 | buffer_ptr(&b), buffer_len(&b)); |
2e73a022 | 872 | if (ret == -1) { |
873 | xfree(blob); | |
874 | buffer_free(&b); | |
875 | return 0; | |
876 | } | |
fa08c86b | 877 | #ifdef DEBUG_PK |
a306f2dd | 878 | buffer_dump(&b); |
879 | #endif | |
cbc5abf9 | 880 | if (datafellows & SSH_BUG_PKSERVICE) { |
d0c832f3 | 881 | buffer_clear(&b); |
882 | buffer_append(&b, session_id2, session_id2_len); | |
fee56204 | 883 | skip = session_id2_len; |
d0c832f3 | 884 | buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST); |
188adeb2 | 885 | buffer_put_cstring(&b, authctxt->server_user); |
886 | buffer_put_cstring(&b, authctxt->service); | |
94ec8c6b | 887 | buffer_put_cstring(&b, authctxt->method->name); |
888 | buffer_put_char(&b, have_sig); | |
cbc5abf9 | 889 | if (!(datafellows & SSH_BUG_PKAUTH)) |
43348518 | 890 | buffer_put_cstring(&b, key_ssh_name(id->key)); |
d0c832f3 | 891 | buffer_put_string(&b, blob, bloblen); |
892 | } | |
893 | xfree(blob); | |
fee56204 | 894 | |
a306f2dd | 895 | /* append signature */ |
896 | buffer_put_string(&b, signature, slen); | |
897 | xfree(signature); | |
898 | ||
899 | /* skip session id and packet type */ | |
74fc9186 | 900 | if (buffer_len(&b) < skip + 1) |
188adeb2 | 901 | fatal("userauth_pubkey: internal error"); |
74fc9186 | 902 | buffer_consume(&b, skip + 1); |
a306f2dd | 903 | |
904 | /* put remaining data from buffer into packet */ | |
905 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
906 | packet_put_raw(buffer_ptr(&b), buffer_len(&b)); | |
907 | buffer_free(&b); | |
a306f2dd | 908 | packet_send(); |
2e73a022 | 909 | |
910 | return 1; | |
4c8722d9 | 911 | } |
912 | ||
396c147e | 913 | static int |
43348518 | 914 | send_pubkey_test(Authctxt *authctxt, Identity *id) |
4c8722d9 | 915 | { |
fee56204 | 916 | u_char *blob; |
21b30f38 | 917 | u_int bloblen, have_sig = 0; |
4c8722d9 | 918 | |
fee56204 | 919 | debug3("send_pubkey_test"); |
920 | ||
43348518 | 921 | if (key_to_blob(id->key, &blob, &bloblen) == 0) { |
fee56204 | 922 | /* we cannot handle this key */ |
923 | debug3("send_pubkey_test: cannot handle key"); | |
4c8722d9 | 924 | return 0; |
925 | } | |
fee56204 | 926 | /* register callback for USERAUTH_PK_OK message */ |
fee56204 | 927 | dispatch_set(SSH2_MSG_USERAUTH_PK_OK, &input_userauth_pk_ok); |
4c8722d9 | 928 | |
fee56204 | 929 | packet_start(SSH2_MSG_USERAUTH_REQUEST); |
930 | packet_put_cstring(authctxt->server_user); | |
931 | packet_put_cstring(authctxt->service); | |
932 | packet_put_cstring(authctxt->method->name); | |
933 | packet_put_char(have_sig); | |
934 | if (!(datafellows & SSH_BUG_PKAUTH)) | |
43348518 | 935 | packet_put_cstring(key_ssh_name(id->key)); |
fee56204 | 936 | packet_put_string(blob, bloblen); |
937 | xfree(blob); | |
938 | packet_send(); | |
939 | return 1; | |
940 | } | |
941 | ||
396c147e | 942 | static Key * |
fee56204 | 943 | load_identity_file(char *filename) |
944 | { | |
945 | Key *private; | |
946 | char prompt[300], *passphrase; | |
aeaa3d9e | 947 | int quit, i; |
d156519a | 948 | struct stat st; |
fee56204 | 949 | |
d156519a | 950 | if (stat(filename, &st) < 0) { |
951 | debug3("no such identity: %s", filename); | |
952 | return NULL; | |
953 | } | |
aeaa3d9e | 954 | private = key_load_private_type(KEY_UNSPEC, filename, "", NULL); |
955 | if (private == NULL) { | |
956 | if (options.batch_mode) | |
fee56204 | 957 | return NULL; |
4c8722d9 | 958 | snprintf(prompt, sizeof prompt, |
184eed6a | 959 | "Enter passphrase for key '%.100s': ", filename); |
188adeb2 | 960 | for (i = 0; i < options.number_of_password_prompts; i++) { |
961 | passphrase = read_passphrase(prompt, 0); | |
962 | if (strcmp(passphrase, "") != 0) { | |
aeaa3d9e | 963 | private = key_load_private_type(KEY_UNSPEC, filename, |
964 | passphrase, NULL); | |
fee56204 | 965 | quit = 0; |
188adeb2 | 966 | } else { |
967 | debug2("no passphrase given, try next key"); | |
fee56204 | 968 | quit = 1; |
188adeb2 | 969 | } |
970 | memset(passphrase, 0, strlen(passphrase)); | |
971 | xfree(passphrase); | |
aeaa3d9e | 972 | if (private != NULL || quit) |
188adeb2 | 973 | break; |
974 | debug2("bad passphrase given, try again..."); | |
975 | } | |
4c8722d9 | 976 | } |
fee56204 | 977 | return private; |
978 | } | |
979 | ||
43348518 | 980 | /* |
981 | * try keys in the following order: | |
982 | * 1. agent keys that are found in the config file | |
983 | * 2. other agent keys | |
984 | * 3. keys that are only listed in the config file | |
985 | */ | |
986 | static void | |
987 | pubkey_prepare(Authctxt *authctxt) | |
fee56204 | 988 | { |
43348518 | 989 | Identity *id; |
990 | Idlist agent, files, *preferred; | |
991 | Key *key; | |
992 | AuthenticationConnection *ac; | |
993 | char *comment; | |
994 | int i, found; | |
995 | ||
996 | TAILQ_INIT(&agent); /* keys from the agent */ | |
997 | TAILQ_INIT(&files); /* keys from the config file */ | |
998 | preferred = &authctxt->keys; | |
999 | TAILQ_INIT(preferred); /* preferred order of keys */ | |
1000 | ||
1001 | /* list of keys stored in the filesystem */ | |
1002 | for (i = 0; i < options.num_identity_files; i++) { | |
1003 | key = options.identity_keys[i]; | |
1004 | if (key && key->type == KEY_RSA1) | |
1005 | continue; | |
1006 | options.identity_keys[i] = NULL; | |
1007 | id = xmalloc(sizeof(*id)); | |
1008 | memset(id, 0, sizeof(*id)); | |
1009 | id->key = key; | |
1010 | id->filename = xstrdup(options.identity_files[i]); | |
1011 | TAILQ_INSERT_TAIL(&files, id, next); | |
1012 | } | |
1013 | /* list of keys supported by the agent */ | |
1014 | if ((ac = ssh_get_authentication_connection())) { | |
1015 | for (key = ssh_get_first_identity(ac, &comment, 2); | |
1016 | key != NULL; | |
1017 | key = ssh_get_next_identity(ac, &comment, 2)) { | |
1018 | found = 0; | |
1019 | TAILQ_FOREACH(id, &files, next) { | |
1020 | /* agent keys from the config file are preferred */ | |
1021 | if (key_equal(key, id->key)) { | |
1022 | key_free(key); | |
1023 | xfree(comment); | |
1024 | TAILQ_REMOVE(&files, id, next); | |
1025 | TAILQ_INSERT_TAIL(preferred, id, next); | |
1026 | id->ac = ac; | |
1027 | found = 1; | |
1028 | break; | |
1029 | } | |
1030 | } | |
1031 | if (!found) { | |
1032 | id = xmalloc(sizeof(*id)); | |
1033 | memset(id, 0, sizeof(*id)); | |
1034 | id->key = key; | |
1035 | id->filename = comment; | |
1036 | id->ac = ac; | |
1037 | TAILQ_INSERT_TAIL(&agent, id, next); | |
1038 | } | |
1039 | } | |
1040 | /* append remaining agent keys */ | |
1041 | for (id = TAILQ_FIRST(&agent); id; id = TAILQ_FIRST(&agent)) { | |
1042 | TAILQ_REMOVE(&agent, id, next); | |
1043 | TAILQ_INSERT_TAIL(preferred, id, next); | |
1044 | } | |
1045 | authctxt->agent = ac; | |
1046 | } | |
1047 | /* append remaining keys from the config file */ | |
1048 | for (id = TAILQ_FIRST(&files); id; id = TAILQ_FIRST(&files)) { | |
1049 | TAILQ_REMOVE(&files, id, next); | |
1050 | TAILQ_INSERT_TAIL(preferred, id, next); | |
1051 | } | |
1052 | TAILQ_FOREACH(id, preferred, next) { | |
1053 | debug2("key: %s (%p)", id->filename, id->key); | |
1054 | } | |
fee56204 | 1055 | } |
1056 | ||
43348518 | 1057 | static void |
1058 | pubkey_cleanup(Authctxt *authctxt) | |
2e73a022 | 1059 | { |
43348518 | 1060 | Identity *id; |
1061 | ||
1062 | if (authctxt->agent != NULL) | |
1063 | ssh_close_authentication_connection(authctxt->agent); | |
1064 | for (id = TAILQ_FIRST(&authctxt->keys); id; | |
1065 | id = TAILQ_FIRST(&authctxt->keys)) { | |
1066 | TAILQ_REMOVE(&authctxt->keys, id, next); | |
1067 | if (id->key) | |
1068 | key_free(id->key); | |
1069 | if (id->filename) | |
1070 | xfree(id->filename); | |
1071 | xfree(id); | |
2e73a022 | 1072 | } |
a306f2dd | 1073 | } |
1074 | ||
188adeb2 | 1075 | int |
1076 | userauth_pubkey(Authctxt *authctxt) | |
a306f2dd | 1077 | { |
43348518 | 1078 | Identity *id; |
188adeb2 | 1079 | int sent = 0; |
1080 | ||
43348518 | 1081 | while ((id = TAILQ_FIRST(&authctxt->keys))) { |
1082 | if (id->tried++) | |
1083 | return (0); | |
1084 | TAILQ_REMOVE(&authctxt->keys, id, next); | |
1085 | TAILQ_INSERT_TAIL(&authctxt->keys, id, next); | |
1086 | /* | |
1087 | * send a test message if we have the public key. for | |
1088 | * encrypted keys we cannot do this and have to load the | |
1089 | * private key instead | |
1090 | */ | |
1091 | if (id->key && id->key->type != KEY_RSA1) { | |
1092 | debug("Offering public key: %s", id->filename); | |
1093 | sent = send_pubkey_test(authctxt, id); | |
1094 | } else if (id->key == NULL) { | |
1095 | debug("Trying private key: %s", id->filename); | |
1096 | id->key = load_identity_file(id->filename); | |
1097 | if (id->key != NULL) { | |
1098 | id->isprivate = 1; | |
1099 | sent = sign_and_send_pubkey(authctxt, id); | |
1100 | key_free(id->key); | |
1101 | id->key = NULL; | |
fee56204 | 1102 | } |
fee56204 | 1103 | } |
43348518 | 1104 | if (sent) |
1105 | return (sent); | |
fa08c86b | 1106 | } |
43348518 | 1107 | return (0); |
188adeb2 | 1108 | } |
a306f2dd | 1109 | |
94ec8c6b | 1110 | /* |
1111 | * Send userauth request message specifying keyboard-interactive method. | |
1112 | */ | |
1113 | int | |
1114 | userauth_kbdint(Authctxt *authctxt) | |
1115 | { | |
1116 | static int attempt = 0; | |
1117 | ||
1118 | if (attempt++ >= options.number_of_password_prompts) | |
1119 | return 0; | |
6b759005 | 1120 | /* disable if no SSH2_MSG_USERAUTH_INFO_REQUEST has been seen */ |
1121 | if (attempt > 1 && !authctxt->info_req_seen) { | |
1122 | debug3("userauth_kbdint: disable: no info_req_seen"); | |
1123 | dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, NULL); | |
1124 | return 0; | |
1125 | } | |
94ec8c6b | 1126 | |
1127 | debug2("userauth_kbdint"); | |
1128 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
1129 | packet_put_cstring(authctxt->server_user); | |
1130 | packet_put_cstring(authctxt->service); | |
1131 | packet_put_cstring(authctxt->method->name); | |
1132 | packet_put_cstring(""); /* lang */ | |
1133 | packet_put_cstring(options.kbd_interactive_devices ? | |
1134 | options.kbd_interactive_devices : ""); | |
1135 | packet_send(); | |
94ec8c6b | 1136 | |
1137 | dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, &input_userauth_info_req); | |
1138 | return 1; | |
1139 | } | |
1140 | ||
1141 | /* | |
f72e01a5 | 1142 | * parse INFO_REQUEST, prompt user and send INFO_RESPONSE |
94ec8c6b | 1143 | */ |
1144 | void | |
7819b5c3 | 1145 | input_userauth_info_req(int type, u_int32_t seq, void *ctxt) |
94ec8c6b | 1146 | { |
1147 | Authctxt *authctxt = ctxt; | |
f72e01a5 | 1148 | char *name, *inst, *lang, *prompt, *response; |
1e3b8b07 | 1149 | u_int num_prompts, i; |
94ec8c6b | 1150 | int echo = 0; |
1151 | ||
1152 | debug2("input_userauth_info_req"); | |
1153 | ||
1154 | if (authctxt == NULL) | |
1155 | fatal("input_userauth_info_req: no authentication context"); | |
1156 | ||
6b759005 | 1157 | authctxt->info_req_seen = 1; |
1158 | ||
94ec8c6b | 1159 | name = packet_get_string(NULL); |
1160 | inst = packet_get_string(NULL); | |
1161 | lang = packet_get_string(NULL); | |
94ec8c6b | 1162 | if (strlen(name) > 0) |
bbe88b6d | 1163 | logit("%s", name); |
94ec8c6b | 1164 | if (strlen(inst) > 0) |
bbe88b6d | 1165 | logit("%s", inst); |
f72e01a5 | 1166 | xfree(name); |
94ec8c6b | 1167 | xfree(inst); |
f72e01a5 | 1168 | xfree(lang); |
94ec8c6b | 1169 | |
1170 | num_prompts = packet_get_int(); | |
1171 | /* | |
1172 | * Begin to build info response packet based on prompts requested. | |
1173 | * We commit to providing the correct number of responses, so if | |
1174 | * further on we run into a problem that prevents this, we have to | |
1175 | * be sure and clean this up and send a correct error response. | |
1176 | */ | |
1177 | packet_start(SSH2_MSG_USERAUTH_INFO_RESPONSE); | |
1178 | packet_put_int(num_prompts); | |
1179 | ||
5ba55ada | 1180 | debug2("input_userauth_info_req: num_prompts %d", num_prompts); |
94ec8c6b | 1181 | for (i = 0; i < num_prompts; i++) { |
1182 | prompt = packet_get_string(NULL); | |
1183 | echo = packet_get_char(); | |
1184 | ||
1843a425 | 1185 | response = read_passphrase(prompt, echo ? RP_ECHO : 0); |
94ec8c6b | 1186 | |
a6215e53 | 1187 | packet_put_cstring(response); |
94ec8c6b | 1188 | memset(response, 0, strlen(response)); |
1189 | xfree(response); | |
1190 | xfree(prompt); | |
1191 | } | |
95500969 | 1192 | packet_check_eom(); /* done with parsing incoming message. */ |
94ec8c6b | 1193 | |
b4b701be | 1194 | packet_add_padding(64); |
94ec8c6b | 1195 | packet_send(); |
94ec8c6b | 1196 | } |
a306f2dd | 1197 | |
39c00dc2 | 1198 | static int |
d6133f43 | 1199 | ssh_keysign(Key *key, u_char **sigp, u_int *lenp, |
39c00dc2 | 1200 | u_char *data, u_int datalen) |
1201 | { | |
1202 | Buffer b; | |
7091a26b | 1203 | struct stat st; |
39c00dc2 | 1204 | pid_t pid; |
d4826734 | 1205 | int to[2], from[2], status, version = 2; |
39c00dc2 | 1206 | |
6226a8f8 | 1207 | debug2("ssh_keysign called"); |
39c00dc2 | 1208 | |
7091a26b | 1209 | if (stat(_PATH_SSH_KEY_SIGN, &st) < 0) { |
1210 | error("ssh_keysign: no installed: %s", strerror(errno)); | |
1211 | return -1; | |
1212 | } | |
39c00dc2 | 1213 | if (fflush(stdout) != 0) |
1214 | error("ssh_keysign: fflush: %s", strerror(errno)); | |
1215 | if (pipe(to) < 0) { | |
1216 | error("ssh_keysign: pipe: %s", strerror(errno)); | |
1217 | return -1; | |
1218 | } | |
1219 | if (pipe(from) < 0) { | |
1220 | error("ssh_keysign: pipe: %s", strerror(errno)); | |
1221 | return -1; | |
1222 | } | |
1223 | if ((pid = fork()) < 0) { | |
1224 | error("ssh_keysign: fork: %s", strerror(errno)); | |
1225 | return -1; | |
1226 | } | |
1227 | if (pid == 0) { | |
1228 | seteuid(getuid()); | |
1229 | setuid(getuid()); | |
1230 | close(from[0]); | |
1231 | if (dup2(from[1], STDOUT_FILENO) < 0) | |
1232 | fatal("ssh_keysign: dup2: %s", strerror(errno)); | |
1233 | close(to[1]); | |
1234 | if (dup2(to[0], STDIN_FILENO) < 0) | |
1235 | fatal("ssh_keysign: dup2: %s", strerror(errno)); | |
d4826734 | 1236 | close(from[1]); |
1237 | close(to[0]); | |
a3f69458 | 1238 | execl(_PATH_SSH_KEY_SIGN, _PATH_SSH_KEY_SIGN, (char *) 0); |
39c00dc2 | 1239 | fatal("ssh_keysign: exec(%s): %s", _PATH_SSH_KEY_SIGN, |
1240 | strerror(errno)); | |
1241 | } | |
1242 | close(from[1]); | |
1243 | close(to[0]); | |
1244 | ||
1245 | buffer_init(&b); | |
d4826734 | 1246 | buffer_put_int(&b, packet_get_connection_in()); /* send # of socket */ |
39c00dc2 | 1247 | buffer_put_string(&b, data, datalen); |
e987fdbe | 1248 | ssh_msg_send(to[1], version, &b); |
39c00dc2 | 1249 | |
e987fdbe | 1250 | if (ssh_msg_recv(from[0], &b) < 0) { |
7091a26b | 1251 | error("ssh_keysign: no reply"); |
39c00dc2 | 1252 | buffer_clear(&b); |
1253 | return -1; | |
1254 | } | |
39c00dc2 | 1255 | close(from[0]); |
1256 | close(to[1]); | |
1257 | ||
d4826734 | 1258 | while (waitpid(pid, &status, 0) < 0) |
1259 | if (errno != EINTR) | |
1260 | break; | |
39c00dc2 | 1261 | |
7091a26b | 1262 | if (buffer_get_char(&b) != version) { |
1263 | error("ssh_keysign: bad version"); | |
1264 | buffer_clear(&b); | |
1265 | return -1; | |
1266 | } | |
1267 | *sigp = buffer_get_string(&b, lenp); | |
1268 | buffer_clear(&b); | |
1269 | ||
39c00dc2 | 1270 | return 0; |
1271 | } | |
1272 | ||
8002af61 | 1273 | int |
1274 | userauth_hostbased(Authctxt *authctxt) | |
1275 | { | |
1276 | Key *private = NULL; | |
39c00dc2 | 1277 | Sensitive *sensitive = authctxt->sensitive; |
8002af61 | 1278 | Buffer b; |
1279 | u_char *signature, *blob; | |
1280 | char *chost, *pkalg, *p; | |
8dddf799 | 1281 | const char *service; |
8002af61 | 1282 | u_int blen, slen; |
f98c3421 | 1283 | int ok, i, len, found = 0; |
8002af61 | 1284 | |
8002af61 | 1285 | /* check for a useful key */ |
39c00dc2 | 1286 | for (i = 0; i < sensitive->nkeys; i++) { |
1287 | private = sensitive->keys[i]; | |
8002af61 | 1288 | if (private && private->type != KEY_RSA1) { |
1289 | found = 1; | |
1290 | /* we take and free the key */ | |
39c00dc2 | 1291 | sensitive->keys[i] = NULL; |
8002af61 | 1292 | break; |
1293 | } | |
1294 | } | |
1295 | if (!found) { | |
6226a8f8 | 1296 | debug("No more client hostkeys for hostbased authentication."); |
8002af61 | 1297 | return 0; |
1298 | } | |
1299 | if (key_to_blob(private, &blob, &blen) == 0) { | |
1300 | key_free(private); | |
8002af61 | 1301 | return 0; |
1302 | } | |
e8d59b4d | 1303 | /* figure out a name for the client host */ |
1304 | p = get_local_name(packet_get_connection_in()); | |
1305 | if (p == NULL) { | |
1306 | error("userauth_hostbased: cannot get local ipaddr/name"); | |
1307 | key_free(private); | |
1308 | return 0; | |
1309 | } | |
1310 | len = strlen(p) + 2; | |
1311 | chost = xmalloc(len); | |
1312 | strlcpy(chost, p, len); | |
1313 | strlcat(chost, ".", len); | |
1314 | debug2("userauth_hostbased: chost %s", chost); | |
3e2f2431 | 1315 | xfree(p); |
e8d59b4d | 1316 | |
8dddf799 | 1317 | service = datafellows & SSH_BUG_HBSERVICE ? "ssh-userauth" : |
1318 | authctxt->service; | |
8002af61 | 1319 | pkalg = xstrdup(key_ssh_name(private)); |
1320 | buffer_init(&b); | |
8002af61 | 1321 | /* construct data */ |
8dddf799 | 1322 | buffer_put_string(&b, session_id2, session_id2_len); |
8002af61 | 1323 | buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST); |
1324 | buffer_put_cstring(&b, authctxt->server_user); | |
8dddf799 | 1325 | buffer_put_cstring(&b, service); |
8002af61 | 1326 | buffer_put_cstring(&b, authctxt->method->name); |
1327 | buffer_put_cstring(&b, pkalg); | |
1328 | buffer_put_string(&b, blob, blen); | |
1329 | buffer_put_cstring(&b, chost); | |
1330 | buffer_put_cstring(&b, authctxt->local_user); | |
1331 | #ifdef DEBUG_PK | |
1332 | buffer_dump(&b); | |
1333 | #endif | |
39c00dc2 | 1334 | if (sensitive->external_keysign) |
1335 | ok = ssh_keysign(private, &signature, &slen, | |
1336 | buffer_ptr(&b), buffer_len(&b)); | |
1337 | else | |
1338 | ok = key_sign(private, &signature, &slen, | |
1339 | buffer_ptr(&b), buffer_len(&b)); | |
8002af61 | 1340 | key_free(private); |
1341 | buffer_free(&b); | |
1342 | if (ok != 0) { | |
1343 | error("key_sign failed"); | |
1344 | xfree(chost); | |
1345 | xfree(pkalg); | |
1346 | return 0; | |
1347 | } | |
1348 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
1349 | packet_put_cstring(authctxt->server_user); | |
1350 | packet_put_cstring(authctxt->service); | |
1351 | packet_put_cstring(authctxt->method->name); | |
1352 | packet_put_cstring(pkalg); | |
1353 | packet_put_string(blob, blen); | |
1354 | packet_put_cstring(chost); | |
1355 | packet_put_cstring(authctxt->local_user); | |
1356 | packet_put_string(signature, slen); | |
1357 | memset(signature, 's', slen); | |
1358 | xfree(signature); | |
1359 | xfree(chost); | |
1360 | xfree(pkalg); | |
1361 | ||
1362 | packet_send(); | |
1363 | return 1; | |
1364 | } | |
1365 | ||
188adeb2 | 1366 | /* find auth method */ |
1367 | ||
188adeb2 | 1368 | /* |
1369 | * given auth method name, if configurable options permit this method fill | |
1370 | * in auth_ident field and return true, otherwise return false. | |
1371 | */ | |
396c147e | 1372 | static int |
188adeb2 | 1373 | authmethod_is_enabled(Authmethod *method) |
1374 | { | |
1375 | if (method == NULL) | |
1376 | return 0; | |
1377 | /* return false if options indicate this method is disabled */ | |
1378 | if (method->enabled == NULL || *method->enabled == 0) | |
1379 | return 0; | |
1380 | /* return false if batch mode is enabled but method needs interactive mode */ | |
1381 | if (method->batch_flag != NULL && *method->batch_flag != 0) | |
1382 | return 0; | |
1383 | return 1; | |
1384 | } | |
a306f2dd | 1385 | |
396c147e | 1386 | static Authmethod * |
188adeb2 | 1387 | authmethod_lookup(const char *name) |
1388 | { | |
1389 | Authmethod *method = NULL; | |
1390 | if (name != NULL) | |
1391 | for (method = authmethods; method->name != NULL; method++) | |
1392 | if (strcmp(name, method->name) == 0) | |
1393 | return method; | |
1394 | debug2("Unrecognized authentication method name: %s", name ? name : "NULL"); | |
1395 | return NULL; | |
1396 | } | |
1397 | ||
cab80f75 | 1398 | /* XXX internal state */ |
1399 | static Authmethod *current = NULL; | |
1400 | static char *supported = NULL; | |
1401 | static char *preferred = NULL; | |
d6133f43 | 1402 | |
188adeb2 | 1403 | /* |
1404 | * Given the authentication method list sent by the server, return the | |
1405 | * next method we should try. If the server initially sends a nil list, | |
cd332296 | 1406 | * use a built-in default list. |
2b87da3b | 1407 | */ |
396c147e | 1408 | static Authmethod * |
188adeb2 | 1409 | authmethod_get(char *authlist) |
1410 | { | |
cab80f75 | 1411 | char *name = NULL; |
21b30f38 | 1412 | u_int next; |
2b87da3b | 1413 | |
188adeb2 | 1414 | /* Use a suitable default if we're passed a nil list. */ |
1415 | if (authlist == NULL || strlen(authlist) == 0) | |
cab80f75 | 1416 | authlist = options.preferred_authentications; |
1417 | ||
1418 | if (supported == NULL || strcmp(authlist, supported) != 0) { | |
1419 | debug3("start over, passed a different list %s", authlist); | |
1420 | if (supported != NULL) | |
1421 | xfree(supported); | |
1422 | supported = xstrdup(authlist); | |
1423 | preferred = options.preferred_authentications; | |
1424 | debug3("preferred %s", preferred); | |
1425 | current = NULL; | |
1426 | } else if (current != NULL && authmethod_is_enabled(current)) | |
1427 | return current; | |
188adeb2 | 1428 | |
cab80f75 | 1429 | for (;;) { |
1430 | if ((name = match_list(preferred, supported, &next)) == NULL) { | |
6226a8f8 | 1431 | debug("No more authentication methods to try."); |
cab80f75 | 1432 | current = NULL; |
1433 | return NULL; | |
1434 | } | |
1435 | preferred += next; | |
94ec8c6b | 1436 | debug3("authmethod_lookup %s", name); |
cab80f75 | 1437 | debug3("remaining preferred: %s", preferred); |
1438 | if ((current = authmethod_lookup(name)) != NULL && | |
1439 | authmethod_is_enabled(current)) { | |
94ec8c6b | 1440 | debug3("authmethod_is_enabled %s", name); |
6226a8f8 | 1441 | debug("Next authentication method: %s", name); |
cab80f75 | 1442 | return current; |
94ec8c6b | 1443 | } |
a306f2dd | 1444 | } |
cab80f75 | 1445 | } |
a22aff1f | 1446 | |
ffb215be | 1447 | static char * |
cab80f75 | 1448 | authmethods_get(void) |
1449 | { | |
1450 | Authmethod *method = NULL; | |
3469eac4 | 1451 | Buffer b; |
1452 | char *list; | |
cab80f75 | 1453 | |
3469eac4 | 1454 | buffer_init(&b); |
cab80f75 | 1455 | for (method = authmethods; method->name != NULL; method++) { |
1456 | if (authmethod_is_enabled(method)) { | |
3469eac4 | 1457 | if (buffer_len(&b) > 0) |
1458 | buffer_append(&b, ",", 1); | |
1459 | buffer_append(&b, method->name, strlen(method->name)); | |
cab80f75 | 1460 | } |
1461 | } | |
3469eac4 | 1462 | buffer_append(&b, "\0", 1); |
1463 | list = xstrdup(buffer_ptr(&b)); | |
1464 | buffer_free(&b); | |
1465 | return list; | |
a306f2dd | 1466 | } |