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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" | |
d3cbe6f8 | 26 | RCSID("$OpenBSD: sshconnect2.c,v 1.131 2003/11/17 09:45:39 djm 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; | |
c8f0cf13 | 361 | |
9616313f | 362 | debug3("input_userauth_banner"); |
363 | msg = packet_get_string(NULL); | |
364 | lang = packet_get_string(NULL); | |
19e633e7 | 365 | if (options.log_level > SYSLOG_LEVEL_QUIET) |
366 | fprintf(stderr, "%s", msg); | |
9616313f | 367 | xfree(msg); |
368 | xfree(lang); | |
188adeb2 | 369 | } |
d6133f43 | 370 | |
188adeb2 | 371 | void |
7819b5c3 | 372 | input_userauth_success(int type, u_int32_t seq, void *ctxt) |
188adeb2 | 373 | { |
374 | Authctxt *authctxt = ctxt; | |
375 | if (authctxt == NULL) | |
376 | fatal("input_userauth_success: no authentication context"); | |
c8f0cf13 | 377 | if (authctxt->authlist) { |
fee56204 | 378 | xfree(authctxt->authlist); |
c8f0cf13 | 379 | authctxt->authlist = NULL; |
380 | } | |
381 | if (authctxt->methoddata) { | |
7364bd04 | 382 | xfree(authctxt->methoddata); |
c8f0cf13 | 383 | authctxt->methoddata = NULL; |
384 | } | |
188adeb2 | 385 | authctxt->success = 1; /* break out */ |
386 | } | |
d6133f43 | 387 | |
188adeb2 | 388 | void |
7819b5c3 | 389 | input_userauth_failure(int type, u_int32_t seq, void *ctxt) |
188adeb2 | 390 | { |
188adeb2 | 391 | Authctxt *authctxt = ctxt; |
392 | char *authlist = NULL; | |
393 | int partial; | |
188adeb2 | 394 | |
395 | if (authctxt == NULL) | |
396 | fatal("input_userauth_failure: no authentication context"); | |
397 | ||
94ec8c6b | 398 | authlist = packet_get_string(NULL); |
188adeb2 | 399 | partial = packet_get_char(); |
95500969 | 400 | packet_check_eom(); |
188adeb2 | 401 | |
402 | if (partial != 0) | |
bbe88b6d | 403 | logit("Authenticated with partial success."); |
6226a8f8 | 404 | debug("Authentications that can continue: %s", authlist); |
188adeb2 | 405 | |
fee56204 | 406 | userauth(authctxt, authlist); |
407 | } | |
408 | void | |
7819b5c3 | 409 | input_userauth_pk_ok(int type, u_int32_t seq, void *ctxt) |
fee56204 | 410 | { |
411 | Authctxt *authctxt = ctxt; | |
412 | Key *key = NULL; | |
43348518 | 413 | Identity *id = NULL; |
fee56204 | 414 | Buffer b; |
c66f9d0e | 415 | int pktype, sent = 0; |
416 | u_int alen, blen; | |
417 | char *pkalg, *fp; | |
418 | u_char *pkblob; | |
fee56204 | 419 | |
420 | if (authctxt == NULL) | |
421 | fatal("input_userauth_pk_ok: no authentication context"); | |
422 | if (datafellows & SSH_BUG_PKOK) { | |
423 | /* this is similar to SSH_BUG_PKAUTH */ | |
424 | debug2("input_userauth_pk_ok: SSH_BUG_PKOK"); | |
425 | pkblob = packet_get_string(&blen); | |
426 | buffer_init(&b); | |
427 | buffer_append(&b, pkblob, blen); | |
428 | pkalg = buffer_get_string(&b, &alen); | |
429 | buffer_free(&b); | |
430 | } else { | |
431 | pkalg = packet_get_string(&alen); | |
432 | pkblob = packet_get_string(&blen); | |
433 | } | |
95500969 | 434 | packet_check_eom(); |
fee56204 | 435 | |
43348518 | 436 | debug("Server accepts key: pkalg %s blen %u", pkalg, blen); |
fee56204 | 437 | |
43348518 | 438 | if ((pktype = key_type_from_name(pkalg)) == KEY_UNSPEC) { |
439 | debug("unknown pkalg %s", pkalg); | |
440 | goto done; | |
441 | } | |
442 | if ((key = key_from_blob(pkblob, blen)) == NULL) { | |
443 | debug("no key from blob. pkalg %s", pkalg); | |
444 | goto done; | |
445 | } | |
446 | if (key->type != pktype) { | |
447 | error("input_userauth_pk_ok: type mismatch " | |
448 | "for decoded key (received %d, expected %d)", | |
449 | key->type, pktype); | |
450 | goto done; | |
451 | } | |
452 | fp = key_fingerprint(key, SSH_FP_MD5, SSH_FP_HEX); | |
453 | debug2("input_userauth_pk_ok: fp %s", fp); | |
454 | xfree(fp); | |
455 | ||
b56e99e2 | 456 | /* |
457 | * search keys in the reverse order, because last candidate has been | |
458 | * moved to the end of the queue. this also avoids confusion by | |
459 | * duplicate keys | |
460 | */ | |
461 | TAILQ_FOREACH_REVERSE(id, &authctxt->keys, next, idlist) { | |
43348518 | 462 | if (key_equal(key, id->key)) { |
463 | sent = sign_and_send_pubkey(authctxt, id); | |
fee56204 | 464 | break; |
465 | } | |
43348518 | 466 | } |
467 | done: | |
fee56204 | 468 | if (key != NULL) |
469 | key_free(key); | |
470 | xfree(pkalg); | |
471 | xfree(pkblob); | |
472 | ||
343288b8 | 473 | /* try another method if we did not send a packet */ |
fee56204 | 474 | if (sent == 0) |
475 | userauth(authctxt, NULL); | |
188adeb2 | 476 | } |
477 | ||
7364bd04 | 478 | #ifdef GSSAPI |
479 | int | |
480 | userauth_gssapi(Authctxt *authctxt) | |
481 | { | |
482 | Gssctxt *gssctxt = NULL; | |
b0b30ca6 | 483 | static gss_OID_set gss_supported = NULL; |
7364bd04 | 484 | static int mech = 0; |
485 | OM_uint32 min; | |
486 | int ok = 0; | |
487 | ||
488 | /* Try one GSSAPI method at a time, rather than sending them all at | |
489 | * once. */ | |
490 | ||
b0b30ca6 | 491 | if (gss_supported == NULL) |
492 | gss_indicate_mechs(&min, &gss_supported); | |
7364bd04 | 493 | |
494 | /* Check to see if the mechanism is usable before we offer it */ | |
b0b30ca6 | 495 | while (mech < gss_supported->count && !ok) { |
7364bd04 | 496 | if (gssctxt) |
497 | ssh_gssapi_delete_ctx(&gssctxt); | |
498 | ssh_gssapi_build_ctx(&gssctxt); | |
b0b30ca6 | 499 | ssh_gssapi_set_oid(gssctxt, &gss_supported->elements[mech]); |
7364bd04 | 500 | |
501 | /* My DER encoding requires length<128 */ | |
b0b30ca6 | 502 | if (gss_supported->elements[mech].length < 128 && |
7364bd04 | 503 | !GSS_ERROR(ssh_gssapi_import_name(gssctxt, |
504 | authctxt->host))) { | |
505 | ok = 1; /* Mechanism works */ | |
506 | } else { | |
507 | mech++; | |
508 | } | |
509 | } | |
510 | ||
511 | if (!ok) return 0; | |
512 | ||
513 | authctxt->methoddata=(void *)gssctxt; | |
514 | ||
515 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
516 | packet_put_cstring(authctxt->server_user); | |
517 | packet_put_cstring(authctxt->service); | |
518 | packet_put_cstring(authctxt->method->name); | |
519 | ||
520 | packet_put_int(1); | |
521 | ||
d8d9afd0 | 522 | packet_put_int((gss_supported->elements[mech].length) + 2); |
523 | packet_put_char(SSH_GSS_OIDTYPE); | |
524 | packet_put_char(gss_supported->elements[mech].length); | |
525 | packet_put_raw(gss_supported->elements[mech].elements, | |
526 | gss_supported->elements[mech].length); | |
7364bd04 | 527 | |
528 | packet_send(); | |
529 | ||
530 | dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE, &input_gssapi_response); | |
531 | dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, &input_gssapi_token); | |
532 | dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERROR, &input_gssapi_error); | |
533 | dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, &input_gssapi_errtok); | |
534 | ||
535 | mech++; /* Move along to next candidate */ | |
536 | ||
537 | return 1; | |
538 | } | |
539 | ||
b930668c | 540 | static OM_uint32 |
541 | process_gssapi_token(void *ctxt, gss_buffer_t recv_tok) | |
542 | { | |
543 | Authctxt *authctxt = ctxt; | |
544 | Gssctxt *gssctxt = authctxt->methoddata; | |
545 | gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER; | |
546 | OM_uint32 status, ms; | |
547 | ||
548 | status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds, | |
549 | recv_tok, &send_tok, NULL); | |
550 | ||
551 | if (send_tok.length > 0) { | |
552 | if (GSS_ERROR(status)) | |
553 | packet_start(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK); | |
554 | else | |
555 | packet_start(SSH2_MSG_USERAUTH_GSSAPI_TOKEN); | |
556 | ||
557 | packet_put_string(send_tok.value, send_tok.length); | |
558 | packet_send(); | |
559 | gss_release_buffer(&ms, &send_tok); | |
560 | } | |
561 | ||
562 | if (status == GSS_S_COMPLETE) { | |
563 | /* If that succeeded, send a exchange complete message */ | |
564 | packet_start(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE); | |
565 | packet_send(); | |
566 | } | |
567 | ||
568 | return status; | |
569 | } | |
570 | ||
7364bd04 | 571 | void |
572 | input_gssapi_response(int type, u_int32_t plen, void *ctxt) | |
573 | { | |
574 | Authctxt *authctxt = ctxt; | |
575 | Gssctxt *gssctxt; | |
7364bd04 | 576 | int oidlen; |
577 | char *oidv; | |
7364bd04 | 578 | |
579 | if (authctxt == NULL) | |
580 | fatal("input_gssapi_response: no authentication context"); | |
581 | gssctxt = authctxt->methoddata; | |
582 | ||
583 | /* Setup our OID */ | |
584 | oidv = packet_get_string(&oidlen); | |
585 | ||
d8d9afd0 | 586 | if (oidlen <= 2 || |
587 | oidv[0] != SSH_GSS_OIDTYPE || | |
588 | oidv[1] != oidlen - 2) { | |
b930668c | 589 | xfree(oidv); |
d8d9afd0 | 590 | debug("Badly encoded mechanism OID received"); |
591 | userauth(authctxt, NULL); | |
d8d9afd0 | 592 | return; |
7364bd04 | 593 | } |
594 | ||
d8d9afd0 | 595 | if (!ssh_gssapi_check_oid(gssctxt, oidv + 2, oidlen - 2)) |
596 | fatal("Server returned different OID than expected"); | |
597 | ||
7364bd04 | 598 | packet_check_eom(); |
599 | ||
600 | xfree(oidv); | |
601 | ||
b930668c | 602 | if (GSS_ERROR(process_gssapi_token(ctxt, GSS_C_NO_BUFFER))) { |
7364bd04 | 603 | /* Start again with next method on list */ |
604 | debug("Trying to start again"); | |
605 | userauth(authctxt, NULL); | |
606 | return; | |
607 | } | |
7364bd04 | 608 | } |
609 | ||
610 | void | |
611 | input_gssapi_token(int type, u_int32_t plen, void *ctxt) | |
612 | { | |
613 | Authctxt *authctxt = ctxt; | |
7364bd04 | 614 | gss_buffer_desc recv_tok; |
b930668c | 615 | OM_uint32 status; |
7364bd04 | 616 | u_int slen; |
617 | ||
618 | if (authctxt == NULL) | |
619 | fatal("input_gssapi_response: no authentication context"); | |
7364bd04 | 620 | |
621 | recv_tok.value = packet_get_string(&slen); | |
622 | recv_tok.length = slen; /* safe typecast */ | |
623 | ||
624 | packet_check_eom(); | |
625 | ||
b930668c | 626 | status = process_gssapi_token(ctxt, &recv_tok); |
7364bd04 | 627 | |
628 | xfree(recv_tok.value); | |
629 | ||
630 | if (GSS_ERROR(status)) { | |
7364bd04 | 631 | /* Start again with the next method in the list */ |
632 | userauth(authctxt, NULL); | |
633 | return; | |
634 | } | |
7364bd04 | 635 | } |
636 | ||
637 | void | |
638 | input_gssapi_errtok(int type, u_int32_t plen, void *ctxt) | |
639 | { | |
640 | Authctxt *authctxt = ctxt; | |
641 | Gssctxt *gssctxt; | |
642 | gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER; | |
643 | gss_buffer_desc recv_tok; | |
644 | OM_uint32 status, ms; | |
f99e1ca4 | 645 | u_int len; |
7364bd04 | 646 | |
647 | if (authctxt == NULL) | |
648 | fatal("input_gssapi_response: no authentication context"); | |
649 | gssctxt = authctxt->methoddata; | |
650 | ||
f99e1ca4 | 651 | recv_tok.value = packet_get_string(&len); |
652 | recv_tok.length = len; | |
7364bd04 | 653 | |
654 | packet_check_eom(); | |
655 | ||
656 | /* Stick it into GSSAPI and see what it says */ | |
657 | status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds, | |
658 | &recv_tok, &send_tok, NULL); | |
659 | ||
660 | xfree(recv_tok.value); | |
661 | gss_release_buffer(&ms, &send_tok); | |
662 | ||
663 | /* Server will be returning a failed packet after this one */ | |
664 | } | |
665 | ||
666 | void | |
667 | input_gssapi_error(int type, u_int32_t plen, void *ctxt) | |
668 | { | |
669 | OM_uint32 maj, min; | |
670 | char *msg; | |
671 | char *lang; | |
672 | ||
673 | maj=packet_get_int(); | |
674 | min=packet_get_int(); | |
675 | msg=packet_get_string(NULL); | |
676 | lang=packet_get_string(NULL); | |
677 | ||
678 | packet_check_eom(); | |
679 | ||
680 | debug("Server GSSAPI Error:\n%s\n", msg); | |
681 | xfree(msg); | |
682 | xfree(lang); | |
683 | } | |
684 | #endif /* GSSAPI */ | |
685 | ||
94ec8c6b | 686 | int |
687 | userauth_none(Authctxt *authctxt) | |
688 | { | |
689 | /* initial userauth request */ | |
690 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
691 | packet_put_cstring(authctxt->server_user); | |
692 | packet_put_cstring(authctxt->service); | |
693 | packet_put_cstring(authctxt->method->name); | |
694 | packet_send(); | |
94ec8c6b | 695 | return 1; |
696 | } | |
697 | ||
a306f2dd | 698 | int |
188adeb2 | 699 | userauth_passwd(Authctxt *authctxt) |
a306f2dd | 700 | { |
1d1ffb87 | 701 | static int attempt = 0; |
67ec167d | 702 | char prompt[150]; |
a306f2dd | 703 | char *password; |
704 | ||
fa649821 | 705 | if (attempt++ >= options.number_of_password_prompts) |
1d1ffb87 | 706 | return 0; |
707 | ||
6aacefa7 | 708 | if (attempt != 1) |
fa649821 | 709 | error("Permission denied, please try again."); |
710 | ||
f72e01a5 | 711 | snprintf(prompt, sizeof(prompt), "%.30s@%.128s's password: ", |
188adeb2 | 712 | authctxt->server_user, authctxt->host); |
a306f2dd | 713 | password = read_passphrase(prompt, 0); |
714 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
188adeb2 | 715 | packet_put_cstring(authctxt->server_user); |
716 | packet_put_cstring(authctxt->service); | |
94ec8c6b | 717 | packet_put_cstring(authctxt->method->name); |
a306f2dd | 718 | packet_put_char(0); |
a6215e53 | 719 | packet_put_cstring(password); |
a306f2dd | 720 | memset(password, 0, strlen(password)); |
721 | xfree(password); | |
b4b701be | 722 | packet_add_padding(64); |
a306f2dd | 723 | packet_send(); |
67ec167d | 724 | |
7203d6bb | 725 | dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, |
67ec167d | 726 | &input_userauth_passwd_changereq); |
727 | ||
a306f2dd | 728 | return 1; |
729 | } | |
67ec167d | 730 | /* |
731 | * parse PASSWD_CHANGEREQ, prompt user and send SSH2_MSG_USERAUTH_REQUEST | |
732 | */ | |
733 | void | |
ef077e37 | 734 | input_userauth_passwd_changereq(int type, u_int32_t seqnr, void *ctxt) |
67ec167d | 735 | { |
736 | Authctxt *authctxt = ctxt; | |
737 | char *info, *lang, *password = NULL, *retype = NULL; | |
738 | char prompt[150]; | |
739 | ||
740 | debug2("input_userauth_passwd_changereq"); | |
741 | ||
742 | if (authctxt == NULL) | |
743 | fatal("input_userauth_passwd_changereq: " | |
744 | "no authentication context"); | |
745 | ||
746 | info = packet_get_string(NULL); | |
747 | lang = packet_get_string(NULL); | |
748 | if (strlen(info) > 0) | |
bbe88b6d | 749 | logit("%s", info); |
67ec167d | 750 | xfree(info); |
751 | xfree(lang); | |
752 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
753 | packet_put_cstring(authctxt->server_user); | |
754 | packet_put_cstring(authctxt->service); | |
755 | packet_put_cstring(authctxt->method->name); | |
756 | packet_put_char(1); /* additional info */ | |
7203d6bb | 757 | snprintf(prompt, sizeof(prompt), |
67ec167d | 758 | "Enter %.30s@%.128s's old password: ", |
759 | authctxt->server_user, authctxt->host); | |
760 | password = read_passphrase(prompt, 0); | |
761 | packet_put_cstring(password); | |
762 | memset(password, 0, strlen(password)); | |
763 | xfree(password); | |
764 | password = NULL; | |
765 | while (password == NULL) { | |
7203d6bb | 766 | snprintf(prompt, sizeof(prompt), |
67ec167d | 767 | "Enter %.30s@%.128s's new password: ", |
768 | authctxt->server_user, authctxt->host); | |
769 | password = read_passphrase(prompt, RP_ALLOW_EOF); | |
770 | if (password == NULL) { | |
771 | /* bail out */ | |
772 | return; | |
773 | } | |
7203d6bb | 774 | snprintf(prompt, sizeof(prompt), |
67ec167d | 775 | "Retype %.30s@%.128s's new password: ", |
776 | authctxt->server_user, authctxt->host); | |
777 | retype = read_passphrase(prompt, 0); | |
778 | if (strcmp(password, retype) != 0) { | |
779 | memset(password, 0, strlen(password)); | |
780 | xfree(password); | |
bbe88b6d | 781 | logit("Mismatch; try again, EOF to quit."); |
67ec167d | 782 | password = NULL; |
783 | } | |
784 | memset(retype, 0, strlen(retype)); | |
785 | xfree(retype); | |
786 | } | |
787 | packet_put_cstring(password); | |
788 | memset(password, 0, strlen(password)); | |
789 | xfree(password); | |
790 | packet_add_padding(64); | |
791 | packet_send(); | |
7203d6bb | 792 | |
793 | dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, | |
67ec167d | 794 | &input_userauth_passwd_changereq); |
795 | } | |
a306f2dd | 796 | |
43348518 | 797 | static int |
798 | identity_sign(Identity *id, u_char **sigp, u_int *lenp, | |
799 | u_char *data, u_int datalen) | |
800 | { | |
801 | Key *prv; | |
802 | int ret; | |
803 | ||
804 | /* the agent supports this key */ | |
805 | if (id->ac) | |
806 | return (ssh_agent_sign(id->ac, id->key, sigp, lenp, | |
807 | data, datalen)); | |
808 | /* | |
809 | * we have already loaded the private key or | |
810 | * the private key is stored in external hardware | |
811 | */ | |
812 | if (id->isprivate || (id->key->flags & KEY_FLAG_EXT)) | |
813 | return (key_sign(id->key, sigp, lenp, data, datalen)); | |
814 | /* load the private key from the file */ | |
815 | if ((prv = load_identity_file(id->filename)) == NULL) | |
816 | return (-1); | |
817 | ret = key_sign(prv, sigp, lenp, data, datalen); | |
818 | key_free(prv); | |
819 | return (ret); | |
fee56204 | 820 | } |
821 | ||
396c147e | 822 | static int |
43348518 | 823 | sign_and_send_pubkey(Authctxt *authctxt, Identity *id) |
a306f2dd | 824 | { |
825 | Buffer b; | |
1e3b8b07 | 826 | u_char *blob, *signature; |
c66f9d0e | 827 | u_int bloblen, slen; |
a27002e5 | 828 | u_int skip = 0; |
2e73a022 | 829 | int ret = -1; |
94ec8c6b | 830 | int have_sig = 1; |
a306f2dd | 831 | |
cbc5abf9 | 832 | debug3("sign_and_send_pubkey"); |
fee56204 | 833 | |
43348518 | 834 | if (key_to_blob(id->key, &blob, &bloblen) == 0) { |
fa08c86b | 835 | /* we cannot handle this key */ |
cbc5abf9 | 836 | debug3("sign_and_send_pubkey: cannot handle key"); |
fa08c86b | 837 | return 0; |
838 | } | |
a306f2dd | 839 | /* data to be signed */ |
840 | buffer_init(&b); | |
33de75a3 | 841 | if (datafellows & SSH_OLD_SESSIONID) { |
74fc9186 | 842 | buffer_append(&b, session_id2, session_id2_len); |
2b87da3b | 843 | skip = session_id2_len; |
33de75a3 | 844 | } else { |
845 | buffer_put_string(&b, session_id2, session_id2_len); | |
846 | skip = buffer_len(&b); | |
74fc9186 | 847 | } |
a306f2dd | 848 | buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST); |
188adeb2 | 849 | buffer_put_cstring(&b, authctxt->server_user); |
d0c832f3 | 850 | buffer_put_cstring(&b, |
cbc5abf9 | 851 | datafellows & SSH_BUG_PKSERVICE ? |
d0c832f3 | 852 | "ssh-userauth" : |
188adeb2 | 853 | authctxt->service); |
cbc5abf9 | 854 | if (datafellows & SSH_BUG_PKAUTH) { |
855 | buffer_put_char(&b, have_sig); | |
856 | } else { | |
857 | buffer_put_cstring(&b, authctxt->method->name); | |
858 | buffer_put_char(&b, have_sig); | |
43348518 | 859 | buffer_put_cstring(&b, key_ssh_name(id->key)); |
cbc5abf9 | 860 | } |
a306f2dd | 861 | buffer_put_string(&b, blob, bloblen); |
a306f2dd | 862 | |
863 | /* generate signature */ | |
43348518 | 864 | ret = identity_sign(id, &signature, &slen, |
fee56204 | 865 | buffer_ptr(&b), buffer_len(&b)); |
2e73a022 | 866 | if (ret == -1) { |
867 | xfree(blob); | |
868 | buffer_free(&b); | |
869 | return 0; | |
870 | } | |
fa08c86b | 871 | #ifdef DEBUG_PK |
a306f2dd | 872 | buffer_dump(&b); |
873 | #endif | |
cbc5abf9 | 874 | if (datafellows & SSH_BUG_PKSERVICE) { |
d0c832f3 | 875 | buffer_clear(&b); |
876 | buffer_append(&b, session_id2, session_id2_len); | |
fee56204 | 877 | skip = session_id2_len; |
d0c832f3 | 878 | buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST); |
188adeb2 | 879 | buffer_put_cstring(&b, authctxt->server_user); |
880 | buffer_put_cstring(&b, authctxt->service); | |
94ec8c6b | 881 | buffer_put_cstring(&b, authctxt->method->name); |
882 | buffer_put_char(&b, have_sig); | |
cbc5abf9 | 883 | if (!(datafellows & SSH_BUG_PKAUTH)) |
43348518 | 884 | buffer_put_cstring(&b, key_ssh_name(id->key)); |
d0c832f3 | 885 | buffer_put_string(&b, blob, bloblen); |
886 | } | |
887 | xfree(blob); | |
fee56204 | 888 | |
a306f2dd | 889 | /* append signature */ |
890 | buffer_put_string(&b, signature, slen); | |
891 | xfree(signature); | |
892 | ||
893 | /* skip session id and packet type */ | |
74fc9186 | 894 | if (buffer_len(&b) < skip + 1) |
188adeb2 | 895 | fatal("userauth_pubkey: internal error"); |
74fc9186 | 896 | buffer_consume(&b, skip + 1); |
a306f2dd | 897 | |
898 | /* put remaining data from buffer into packet */ | |
899 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
900 | packet_put_raw(buffer_ptr(&b), buffer_len(&b)); | |
901 | buffer_free(&b); | |
a306f2dd | 902 | packet_send(); |
2e73a022 | 903 | |
904 | return 1; | |
4c8722d9 | 905 | } |
906 | ||
396c147e | 907 | static int |
43348518 | 908 | send_pubkey_test(Authctxt *authctxt, Identity *id) |
4c8722d9 | 909 | { |
fee56204 | 910 | u_char *blob; |
21b30f38 | 911 | u_int bloblen, have_sig = 0; |
4c8722d9 | 912 | |
fee56204 | 913 | debug3("send_pubkey_test"); |
914 | ||
43348518 | 915 | if (key_to_blob(id->key, &blob, &bloblen) == 0) { |
fee56204 | 916 | /* we cannot handle this key */ |
917 | debug3("send_pubkey_test: cannot handle key"); | |
4c8722d9 | 918 | return 0; |
919 | } | |
fee56204 | 920 | /* register callback for USERAUTH_PK_OK message */ |
fee56204 | 921 | dispatch_set(SSH2_MSG_USERAUTH_PK_OK, &input_userauth_pk_ok); |
4c8722d9 | 922 | |
fee56204 | 923 | packet_start(SSH2_MSG_USERAUTH_REQUEST); |
924 | packet_put_cstring(authctxt->server_user); | |
925 | packet_put_cstring(authctxt->service); | |
926 | packet_put_cstring(authctxt->method->name); | |
927 | packet_put_char(have_sig); | |
928 | if (!(datafellows & SSH_BUG_PKAUTH)) | |
43348518 | 929 | packet_put_cstring(key_ssh_name(id->key)); |
fee56204 | 930 | packet_put_string(blob, bloblen); |
931 | xfree(blob); | |
932 | packet_send(); | |
933 | return 1; | |
934 | } | |
935 | ||
396c147e | 936 | static Key * |
fee56204 | 937 | load_identity_file(char *filename) |
938 | { | |
939 | Key *private; | |
940 | char prompt[300], *passphrase; | |
aeaa3d9e | 941 | int quit, i; |
d156519a | 942 | struct stat st; |
fee56204 | 943 | |
d156519a | 944 | if (stat(filename, &st) < 0) { |
945 | debug3("no such identity: %s", filename); | |
946 | return NULL; | |
947 | } | |
aeaa3d9e | 948 | private = key_load_private_type(KEY_UNSPEC, filename, "", NULL); |
949 | if (private == NULL) { | |
950 | if (options.batch_mode) | |
fee56204 | 951 | return NULL; |
4c8722d9 | 952 | snprintf(prompt, sizeof prompt, |
184eed6a | 953 | "Enter passphrase for key '%.100s': ", filename); |
188adeb2 | 954 | for (i = 0; i < options.number_of_password_prompts; i++) { |
955 | passphrase = read_passphrase(prompt, 0); | |
956 | if (strcmp(passphrase, "") != 0) { | |
aeaa3d9e | 957 | private = key_load_private_type(KEY_UNSPEC, filename, |
958 | passphrase, NULL); | |
fee56204 | 959 | quit = 0; |
188adeb2 | 960 | } else { |
961 | debug2("no passphrase given, try next key"); | |
fee56204 | 962 | quit = 1; |
188adeb2 | 963 | } |
964 | memset(passphrase, 0, strlen(passphrase)); | |
965 | xfree(passphrase); | |
aeaa3d9e | 966 | if (private != NULL || quit) |
188adeb2 | 967 | break; |
968 | debug2("bad passphrase given, try again..."); | |
969 | } | |
4c8722d9 | 970 | } |
fee56204 | 971 | return private; |
972 | } | |
973 | ||
43348518 | 974 | /* |
975 | * try keys in the following order: | |
976 | * 1. agent keys that are found in the config file | |
977 | * 2. other agent keys | |
978 | * 3. keys that are only listed in the config file | |
979 | */ | |
980 | static void | |
981 | pubkey_prepare(Authctxt *authctxt) | |
fee56204 | 982 | { |
43348518 | 983 | Identity *id; |
984 | Idlist agent, files, *preferred; | |
985 | Key *key; | |
986 | AuthenticationConnection *ac; | |
987 | char *comment; | |
988 | int i, found; | |
989 | ||
990 | TAILQ_INIT(&agent); /* keys from the agent */ | |
991 | TAILQ_INIT(&files); /* keys from the config file */ | |
992 | preferred = &authctxt->keys; | |
993 | TAILQ_INIT(preferred); /* preferred order of keys */ | |
994 | ||
995 | /* list of keys stored in the filesystem */ | |
996 | for (i = 0; i < options.num_identity_files; i++) { | |
997 | key = options.identity_keys[i]; | |
998 | if (key && key->type == KEY_RSA1) | |
999 | continue; | |
1000 | options.identity_keys[i] = NULL; | |
1001 | id = xmalloc(sizeof(*id)); | |
1002 | memset(id, 0, sizeof(*id)); | |
1003 | id->key = key; | |
1004 | id->filename = xstrdup(options.identity_files[i]); | |
1005 | TAILQ_INSERT_TAIL(&files, id, next); | |
1006 | } | |
1007 | /* list of keys supported by the agent */ | |
1008 | if ((ac = ssh_get_authentication_connection())) { | |
1009 | for (key = ssh_get_first_identity(ac, &comment, 2); | |
1010 | key != NULL; | |
1011 | key = ssh_get_next_identity(ac, &comment, 2)) { | |
1012 | found = 0; | |
1013 | TAILQ_FOREACH(id, &files, next) { | |
1014 | /* agent keys from the config file are preferred */ | |
1015 | if (key_equal(key, id->key)) { | |
1016 | key_free(key); | |
1017 | xfree(comment); | |
1018 | TAILQ_REMOVE(&files, id, next); | |
1019 | TAILQ_INSERT_TAIL(preferred, id, next); | |
1020 | id->ac = ac; | |
1021 | found = 1; | |
1022 | break; | |
1023 | } | |
1024 | } | |
1025 | if (!found) { | |
1026 | id = xmalloc(sizeof(*id)); | |
1027 | memset(id, 0, sizeof(*id)); | |
1028 | id->key = key; | |
1029 | id->filename = comment; | |
1030 | id->ac = ac; | |
1031 | TAILQ_INSERT_TAIL(&agent, id, next); | |
1032 | } | |
1033 | } | |
1034 | /* append remaining agent keys */ | |
1035 | for (id = TAILQ_FIRST(&agent); id; id = TAILQ_FIRST(&agent)) { | |
1036 | TAILQ_REMOVE(&agent, id, next); | |
1037 | TAILQ_INSERT_TAIL(preferred, id, next); | |
1038 | } | |
1039 | authctxt->agent = ac; | |
1040 | } | |
1041 | /* append remaining keys from the config file */ | |
1042 | for (id = TAILQ_FIRST(&files); id; id = TAILQ_FIRST(&files)) { | |
1043 | TAILQ_REMOVE(&files, id, next); | |
1044 | TAILQ_INSERT_TAIL(preferred, id, next); | |
1045 | } | |
1046 | TAILQ_FOREACH(id, preferred, next) { | |
1047 | debug2("key: %s (%p)", id->filename, id->key); | |
1048 | } | |
fee56204 | 1049 | } |
1050 | ||
43348518 | 1051 | static void |
1052 | pubkey_cleanup(Authctxt *authctxt) | |
2e73a022 | 1053 | { |
43348518 | 1054 | Identity *id; |
1055 | ||
1056 | if (authctxt->agent != NULL) | |
1057 | ssh_close_authentication_connection(authctxt->agent); | |
1058 | for (id = TAILQ_FIRST(&authctxt->keys); id; | |
1059 | id = TAILQ_FIRST(&authctxt->keys)) { | |
1060 | TAILQ_REMOVE(&authctxt->keys, id, next); | |
1061 | if (id->key) | |
1062 | key_free(id->key); | |
1063 | if (id->filename) | |
1064 | xfree(id->filename); | |
1065 | xfree(id); | |
2e73a022 | 1066 | } |
a306f2dd | 1067 | } |
1068 | ||
188adeb2 | 1069 | int |
1070 | userauth_pubkey(Authctxt *authctxt) | |
a306f2dd | 1071 | { |
43348518 | 1072 | Identity *id; |
188adeb2 | 1073 | int sent = 0; |
1074 | ||
43348518 | 1075 | while ((id = TAILQ_FIRST(&authctxt->keys))) { |
1076 | if (id->tried++) | |
1077 | return (0); | |
b56e99e2 | 1078 | /* move key to the end of the queue */ |
43348518 | 1079 | TAILQ_REMOVE(&authctxt->keys, id, next); |
1080 | TAILQ_INSERT_TAIL(&authctxt->keys, id, next); | |
1081 | /* | |
1082 | * send a test message if we have the public key. for | |
1083 | * encrypted keys we cannot do this and have to load the | |
1084 | * private key instead | |
1085 | */ | |
1086 | if (id->key && id->key->type != KEY_RSA1) { | |
1087 | debug("Offering public key: %s", id->filename); | |
1088 | sent = send_pubkey_test(authctxt, id); | |
1089 | } else if (id->key == NULL) { | |
1090 | debug("Trying private key: %s", id->filename); | |
1091 | id->key = load_identity_file(id->filename); | |
1092 | if (id->key != NULL) { | |
1093 | id->isprivate = 1; | |
1094 | sent = sign_and_send_pubkey(authctxt, id); | |
1095 | key_free(id->key); | |
1096 | id->key = NULL; | |
fee56204 | 1097 | } |
fee56204 | 1098 | } |
43348518 | 1099 | if (sent) |
1100 | return (sent); | |
fa08c86b | 1101 | } |
43348518 | 1102 | return (0); |
188adeb2 | 1103 | } |
a306f2dd | 1104 | |
94ec8c6b | 1105 | /* |
1106 | * Send userauth request message specifying keyboard-interactive method. | |
1107 | */ | |
1108 | int | |
1109 | userauth_kbdint(Authctxt *authctxt) | |
1110 | { | |
1111 | static int attempt = 0; | |
1112 | ||
1113 | if (attempt++ >= options.number_of_password_prompts) | |
1114 | return 0; | |
6b759005 | 1115 | /* disable if no SSH2_MSG_USERAUTH_INFO_REQUEST has been seen */ |
1116 | if (attempt > 1 && !authctxt->info_req_seen) { | |
1117 | debug3("userauth_kbdint: disable: no info_req_seen"); | |
1118 | dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, NULL); | |
1119 | return 0; | |
1120 | } | |
94ec8c6b | 1121 | |
1122 | debug2("userauth_kbdint"); | |
1123 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
1124 | packet_put_cstring(authctxt->server_user); | |
1125 | packet_put_cstring(authctxt->service); | |
1126 | packet_put_cstring(authctxt->method->name); | |
1127 | packet_put_cstring(""); /* lang */ | |
1128 | packet_put_cstring(options.kbd_interactive_devices ? | |
1129 | options.kbd_interactive_devices : ""); | |
1130 | packet_send(); | |
94ec8c6b | 1131 | |
1132 | dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, &input_userauth_info_req); | |
1133 | return 1; | |
1134 | } | |
1135 | ||
1136 | /* | |
f72e01a5 | 1137 | * parse INFO_REQUEST, prompt user and send INFO_RESPONSE |
94ec8c6b | 1138 | */ |
1139 | void | |
7819b5c3 | 1140 | input_userauth_info_req(int type, u_int32_t seq, void *ctxt) |
94ec8c6b | 1141 | { |
1142 | Authctxt *authctxt = ctxt; | |
f72e01a5 | 1143 | char *name, *inst, *lang, *prompt, *response; |
1e3b8b07 | 1144 | u_int num_prompts, i; |
94ec8c6b | 1145 | int echo = 0; |
1146 | ||
1147 | debug2("input_userauth_info_req"); | |
1148 | ||
1149 | if (authctxt == NULL) | |
1150 | fatal("input_userauth_info_req: no authentication context"); | |
1151 | ||
6b759005 | 1152 | authctxt->info_req_seen = 1; |
1153 | ||
94ec8c6b | 1154 | name = packet_get_string(NULL); |
1155 | inst = packet_get_string(NULL); | |
1156 | lang = packet_get_string(NULL); | |
94ec8c6b | 1157 | if (strlen(name) > 0) |
bbe88b6d | 1158 | logit("%s", name); |
94ec8c6b | 1159 | if (strlen(inst) > 0) |
bbe88b6d | 1160 | logit("%s", inst); |
f72e01a5 | 1161 | xfree(name); |
94ec8c6b | 1162 | xfree(inst); |
f72e01a5 | 1163 | xfree(lang); |
94ec8c6b | 1164 | |
1165 | num_prompts = packet_get_int(); | |
1166 | /* | |
1167 | * Begin to build info response packet based on prompts requested. | |
1168 | * We commit to providing the correct number of responses, so if | |
1169 | * further on we run into a problem that prevents this, we have to | |
1170 | * be sure and clean this up and send a correct error response. | |
1171 | */ | |
1172 | packet_start(SSH2_MSG_USERAUTH_INFO_RESPONSE); | |
1173 | packet_put_int(num_prompts); | |
1174 | ||
5ba55ada | 1175 | debug2("input_userauth_info_req: num_prompts %d", num_prompts); |
94ec8c6b | 1176 | for (i = 0; i < num_prompts; i++) { |
1177 | prompt = packet_get_string(NULL); | |
1178 | echo = packet_get_char(); | |
1179 | ||
1843a425 | 1180 | response = read_passphrase(prompt, echo ? RP_ECHO : 0); |
94ec8c6b | 1181 | |
a6215e53 | 1182 | packet_put_cstring(response); |
94ec8c6b | 1183 | memset(response, 0, strlen(response)); |
1184 | xfree(response); | |
1185 | xfree(prompt); | |
1186 | } | |
95500969 | 1187 | packet_check_eom(); /* done with parsing incoming message. */ |
94ec8c6b | 1188 | |
b4b701be | 1189 | packet_add_padding(64); |
94ec8c6b | 1190 | packet_send(); |
94ec8c6b | 1191 | } |
a306f2dd | 1192 | |
39c00dc2 | 1193 | static int |
d6133f43 | 1194 | ssh_keysign(Key *key, u_char **sigp, u_int *lenp, |
39c00dc2 | 1195 | u_char *data, u_int datalen) |
1196 | { | |
1197 | Buffer b; | |
7091a26b | 1198 | struct stat st; |
39c00dc2 | 1199 | pid_t pid; |
d4826734 | 1200 | int to[2], from[2], status, version = 2; |
39c00dc2 | 1201 | |
6226a8f8 | 1202 | debug2("ssh_keysign called"); |
39c00dc2 | 1203 | |
7091a26b | 1204 | if (stat(_PATH_SSH_KEY_SIGN, &st) < 0) { |
1205 | error("ssh_keysign: no installed: %s", strerror(errno)); | |
1206 | return -1; | |
1207 | } | |
39c00dc2 | 1208 | if (fflush(stdout) != 0) |
1209 | error("ssh_keysign: fflush: %s", strerror(errno)); | |
1210 | if (pipe(to) < 0) { | |
1211 | error("ssh_keysign: pipe: %s", strerror(errno)); | |
1212 | return -1; | |
1213 | } | |
1214 | if (pipe(from) < 0) { | |
1215 | error("ssh_keysign: pipe: %s", strerror(errno)); | |
1216 | return -1; | |
1217 | } | |
1218 | if ((pid = fork()) < 0) { | |
1219 | error("ssh_keysign: fork: %s", strerror(errno)); | |
1220 | return -1; | |
1221 | } | |
1222 | if (pid == 0) { | |
1223 | seteuid(getuid()); | |
1224 | setuid(getuid()); | |
1225 | close(from[0]); | |
1226 | if (dup2(from[1], STDOUT_FILENO) < 0) | |
1227 | fatal("ssh_keysign: dup2: %s", strerror(errno)); | |
1228 | close(to[1]); | |
1229 | if (dup2(to[0], STDIN_FILENO) < 0) | |
1230 | fatal("ssh_keysign: dup2: %s", strerror(errno)); | |
d4826734 | 1231 | close(from[1]); |
1232 | close(to[0]); | |
a3f69458 | 1233 | execl(_PATH_SSH_KEY_SIGN, _PATH_SSH_KEY_SIGN, (char *) 0); |
39c00dc2 | 1234 | fatal("ssh_keysign: exec(%s): %s", _PATH_SSH_KEY_SIGN, |
1235 | strerror(errno)); | |
1236 | } | |
1237 | close(from[1]); | |
1238 | close(to[0]); | |
1239 | ||
1240 | buffer_init(&b); | |
d4826734 | 1241 | buffer_put_int(&b, packet_get_connection_in()); /* send # of socket */ |
39c00dc2 | 1242 | buffer_put_string(&b, data, datalen); |
d3cbe6f8 | 1243 | if (ssh_msg_send(to[1], version, &b) == -1) |
1244 | fatal("ssh_keysign: couldn't send request"); | |
39c00dc2 | 1245 | |
e987fdbe | 1246 | if (ssh_msg_recv(from[0], &b) < 0) { |
7091a26b | 1247 | error("ssh_keysign: no reply"); |
39c00dc2 | 1248 | buffer_clear(&b); |
1249 | return -1; | |
1250 | } | |
39c00dc2 | 1251 | close(from[0]); |
1252 | close(to[1]); | |
1253 | ||
d4826734 | 1254 | while (waitpid(pid, &status, 0) < 0) |
1255 | if (errno != EINTR) | |
1256 | break; | |
39c00dc2 | 1257 | |
7091a26b | 1258 | if (buffer_get_char(&b) != version) { |
1259 | error("ssh_keysign: bad version"); | |
1260 | buffer_clear(&b); | |
1261 | return -1; | |
1262 | } | |
1263 | *sigp = buffer_get_string(&b, lenp); | |
1264 | buffer_clear(&b); | |
1265 | ||
39c00dc2 | 1266 | return 0; |
1267 | } | |
1268 | ||
8002af61 | 1269 | int |
1270 | userauth_hostbased(Authctxt *authctxt) | |
1271 | { | |
1272 | Key *private = NULL; | |
39c00dc2 | 1273 | Sensitive *sensitive = authctxt->sensitive; |
8002af61 | 1274 | Buffer b; |
1275 | u_char *signature, *blob; | |
1276 | char *chost, *pkalg, *p; | |
8dddf799 | 1277 | const char *service; |
8002af61 | 1278 | u_int blen, slen; |
f98c3421 | 1279 | int ok, i, len, found = 0; |
8002af61 | 1280 | |
8002af61 | 1281 | /* check for a useful key */ |
39c00dc2 | 1282 | for (i = 0; i < sensitive->nkeys; i++) { |
1283 | private = sensitive->keys[i]; | |
8002af61 | 1284 | if (private && private->type != KEY_RSA1) { |
1285 | found = 1; | |
1286 | /* we take and free the key */ | |
39c00dc2 | 1287 | sensitive->keys[i] = NULL; |
8002af61 | 1288 | break; |
1289 | } | |
1290 | } | |
1291 | if (!found) { | |
6226a8f8 | 1292 | debug("No more client hostkeys for hostbased authentication."); |
8002af61 | 1293 | return 0; |
1294 | } | |
1295 | if (key_to_blob(private, &blob, &blen) == 0) { | |
1296 | key_free(private); | |
8002af61 | 1297 | return 0; |
1298 | } | |
e8d59b4d | 1299 | /* figure out a name for the client host */ |
1300 | p = get_local_name(packet_get_connection_in()); | |
1301 | if (p == NULL) { | |
1302 | error("userauth_hostbased: cannot get local ipaddr/name"); | |
1303 | key_free(private); | |
1304 | return 0; | |
1305 | } | |
1306 | len = strlen(p) + 2; | |
1307 | chost = xmalloc(len); | |
1308 | strlcpy(chost, p, len); | |
1309 | strlcat(chost, ".", len); | |
1310 | debug2("userauth_hostbased: chost %s", chost); | |
3e2f2431 | 1311 | xfree(p); |
e8d59b4d | 1312 | |
8dddf799 | 1313 | service = datafellows & SSH_BUG_HBSERVICE ? "ssh-userauth" : |
1314 | authctxt->service; | |
8002af61 | 1315 | pkalg = xstrdup(key_ssh_name(private)); |
1316 | buffer_init(&b); | |
8002af61 | 1317 | /* construct data */ |
8dddf799 | 1318 | buffer_put_string(&b, session_id2, session_id2_len); |
8002af61 | 1319 | buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST); |
1320 | buffer_put_cstring(&b, authctxt->server_user); | |
8dddf799 | 1321 | buffer_put_cstring(&b, service); |
8002af61 | 1322 | buffer_put_cstring(&b, authctxt->method->name); |
1323 | buffer_put_cstring(&b, pkalg); | |
1324 | buffer_put_string(&b, blob, blen); | |
1325 | buffer_put_cstring(&b, chost); | |
1326 | buffer_put_cstring(&b, authctxt->local_user); | |
1327 | #ifdef DEBUG_PK | |
1328 | buffer_dump(&b); | |
1329 | #endif | |
39c00dc2 | 1330 | if (sensitive->external_keysign) |
1331 | ok = ssh_keysign(private, &signature, &slen, | |
1332 | buffer_ptr(&b), buffer_len(&b)); | |
1333 | else | |
1334 | ok = key_sign(private, &signature, &slen, | |
1335 | buffer_ptr(&b), buffer_len(&b)); | |
8002af61 | 1336 | key_free(private); |
1337 | buffer_free(&b); | |
1338 | if (ok != 0) { | |
1339 | error("key_sign failed"); | |
1340 | xfree(chost); | |
1341 | xfree(pkalg); | |
1342 | return 0; | |
1343 | } | |
1344 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
1345 | packet_put_cstring(authctxt->server_user); | |
1346 | packet_put_cstring(authctxt->service); | |
1347 | packet_put_cstring(authctxt->method->name); | |
1348 | packet_put_cstring(pkalg); | |
1349 | packet_put_string(blob, blen); | |
1350 | packet_put_cstring(chost); | |
1351 | packet_put_cstring(authctxt->local_user); | |
1352 | packet_put_string(signature, slen); | |
1353 | memset(signature, 's', slen); | |
1354 | xfree(signature); | |
1355 | xfree(chost); | |
1356 | xfree(pkalg); | |
1357 | ||
1358 | packet_send(); | |
1359 | return 1; | |
1360 | } | |
1361 | ||
188adeb2 | 1362 | /* find auth method */ |
1363 | ||
188adeb2 | 1364 | /* |
1365 | * given auth method name, if configurable options permit this method fill | |
1366 | * in auth_ident field and return true, otherwise return false. | |
1367 | */ | |
396c147e | 1368 | static int |
188adeb2 | 1369 | authmethod_is_enabled(Authmethod *method) |
1370 | { | |
1371 | if (method == NULL) | |
1372 | return 0; | |
1373 | /* return false if options indicate this method is disabled */ | |
1374 | if (method->enabled == NULL || *method->enabled == 0) | |
1375 | return 0; | |
1376 | /* return false if batch mode is enabled but method needs interactive mode */ | |
1377 | if (method->batch_flag != NULL && *method->batch_flag != 0) | |
1378 | return 0; | |
1379 | return 1; | |
1380 | } | |
a306f2dd | 1381 | |
396c147e | 1382 | static Authmethod * |
188adeb2 | 1383 | authmethod_lookup(const char *name) |
1384 | { | |
1385 | Authmethod *method = NULL; | |
1386 | if (name != NULL) | |
1387 | for (method = authmethods; method->name != NULL; method++) | |
1388 | if (strcmp(name, method->name) == 0) | |
1389 | return method; | |
1390 | debug2("Unrecognized authentication method name: %s", name ? name : "NULL"); | |
1391 | return NULL; | |
1392 | } | |
1393 | ||
cab80f75 | 1394 | /* XXX internal state */ |
1395 | static Authmethod *current = NULL; | |
1396 | static char *supported = NULL; | |
1397 | static char *preferred = NULL; | |
d6133f43 | 1398 | |
188adeb2 | 1399 | /* |
1400 | * Given the authentication method list sent by the server, return the | |
1401 | * next method we should try. If the server initially sends a nil list, | |
cd332296 | 1402 | * use a built-in default list. |
2b87da3b | 1403 | */ |
396c147e | 1404 | static Authmethod * |
188adeb2 | 1405 | authmethod_get(char *authlist) |
1406 | { | |
cab80f75 | 1407 | char *name = NULL; |
21b30f38 | 1408 | u_int next; |
2b87da3b | 1409 | |
188adeb2 | 1410 | /* Use a suitable default if we're passed a nil list. */ |
1411 | if (authlist == NULL || strlen(authlist) == 0) | |
cab80f75 | 1412 | authlist = options.preferred_authentications; |
1413 | ||
1414 | if (supported == NULL || strcmp(authlist, supported) != 0) { | |
1415 | debug3("start over, passed a different list %s", authlist); | |
1416 | if (supported != NULL) | |
1417 | xfree(supported); | |
1418 | supported = xstrdup(authlist); | |
1419 | preferred = options.preferred_authentications; | |
1420 | debug3("preferred %s", preferred); | |
1421 | current = NULL; | |
1422 | } else if (current != NULL && authmethod_is_enabled(current)) | |
1423 | return current; | |
188adeb2 | 1424 | |
cab80f75 | 1425 | for (;;) { |
1426 | if ((name = match_list(preferred, supported, &next)) == NULL) { | |
6226a8f8 | 1427 | debug("No more authentication methods to try."); |
cab80f75 | 1428 | current = NULL; |
1429 | return NULL; | |
1430 | } | |
1431 | preferred += next; | |
94ec8c6b | 1432 | debug3("authmethod_lookup %s", name); |
cab80f75 | 1433 | debug3("remaining preferred: %s", preferred); |
1434 | if ((current = authmethod_lookup(name)) != NULL && | |
1435 | authmethod_is_enabled(current)) { | |
94ec8c6b | 1436 | debug3("authmethod_is_enabled %s", name); |
6226a8f8 | 1437 | debug("Next authentication method: %s", name); |
cab80f75 | 1438 | return current; |
94ec8c6b | 1439 | } |
a306f2dd | 1440 | } |
cab80f75 | 1441 | } |
a22aff1f | 1442 | |
ffb215be | 1443 | static char * |
cab80f75 | 1444 | authmethods_get(void) |
1445 | { | |
1446 | Authmethod *method = NULL; | |
3469eac4 | 1447 | Buffer b; |
1448 | char *list; | |
cab80f75 | 1449 | |
3469eac4 | 1450 | buffer_init(&b); |
cab80f75 | 1451 | for (method = authmethods; method->name != NULL; method++) { |
1452 | if (authmethod_is_enabled(method)) { | |
3469eac4 | 1453 | if (buffer_len(&b) > 0) |
1454 | buffer_append(&b, ",", 1); | |
1455 | buffer_append(&b, method->name, strlen(method->name)); | |
cab80f75 | 1456 | } |
1457 | } | |
3469eac4 | 1458 | buffer_append(&b, "\0", 1); |
1459 | list = xstrdup(buffer_ptr(&b)); | |
1460 | buffer_free(&b); | |
1461 | return list; | |
a306f2dd | 1462 | } |