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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" | |
0608f8a7 | 26 | RCSID("$OpenBSD: sshconnect2.c,v 1.116 2003/04/08 20:21:29 itojun Exp $"); |
a306f2dd | 27 | |
28 | #include "ssh.h" | |
42f11eb2 | 29 | #include "ssh2.h" |
a306f2dd | 30 | #include "xmalloc.h" |
a306f2dd | 31 | #include "buffer.h" |
32 | #include "packet.h" | |
a306f2dd | 33 | #include "compat.h" |
a306f2dd | 34 | #include "bufaux.h" |
42f11eb2 | 35 | #include "cipher.h" |
a306f2dd | 36 | #include "kex.h" |
37 | #include "myproposal.h" | |
a306f2dd | 38 | #include "sshconnect.h" |
39 | #include "authfile.h" | |
db1cd2f3 | 40 | #include "dh.h" |
2e73a022 | 41 | #include "authfd.h" |
42f11eb2 | 42 | #include "log.h" |
43 | #include "readconf.h" | |
44 | #include "readpass.h" | |
cab80f75 | 45 | #include "match.h" |
a5c9ffdb | 46 | #include "dispatch.h" |
8002af61 | 47 | #include "canohost.h" |
39c00dc2 | 48 | #include "msg.h" |
49 | #include "pathnames.h" | |
94ec8c6b | 50 | |
a306f2dd | 51 | /* import */ |
52 | extern char *client_version_string; | |
53 | extern char *server_version_string; | |
54 | extern Options options; | |
55 | ||
56 | /* | |
57 | * SSH2 key exchange | |
58 | */ | |
59 | ||
1e3b8b07 | 60 | u_char *session_id2 = NULL; |
a306f2dd | 61 | int session_id2_len = 0; |
62 | ||
a5c9ffdb | 63 | char *xxx_host; |
64 | struct sockaddr *xxx_hostaddr; | |
65 | ||
e092ce67 | 66 | Kex *xxx_kex = NULL; |
67 | ||
396c147e | 68 | static int |
f49bc4f7 | 69 | verify_host_key_callback(Key *hostkey) |
a5c9ffdb | 70 | { |
f49bc4f7 | 71 | if (verify_host_key(xxx_host, xxx_hostaddr, hostkey) == -1) |
01e9ef57 | 72 | fatal("Host key verification failed."); |
a5c9ffdb | 73 | return 0; |
74 | } | |
75 | ||
a306f2dd | 76 | void |
94ec8c6b | 77 | ssh_kex2(char *host, struct sockaddr *hostaddr) |
78 | { | |
94ec8c6b | 79 | Kex *kex; |
a5c9ffdb | 80 | |
81 | xxx_host = host; | |
82 | xxx_hostaddr = hostaddr; | |
94ec8c6b | 83 | |
c523303b | 84 | if (options.ciphers == (char *)-1) { |
bbe88b6d | 85 | logit("No valid ciphers for protocol version 2 given, using defaults."); |
c523303b | 86 | options.ciphers = NULL; |
94ec8c6b | 87 | } |
88 | if (options.ciphers != NULL) { | |
89 | myproposal[PROPOSAL_ENC_ALGS_CTOS] = | |
90 | myproposal[PROPOSAL_ENC_ALGS_STOC] = options.ciphers; | |
91 | } | |
1ad64a93 | 92 | myproposal[PROPOSAL_ENC_ALGS_CTOS] = |
93 | compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_CTOS]); | |
94 | myproposal[PROPOSAL_ENC_ALGS_STOC] = | |
95 | compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_STOC]); | |
94ec8c6b | 96 | if (options.compression) { |
b2552997 | 97 | myproposal[PROPOSAL_COMP_ALGS_CTOS] = |
713f6cd9 | 98 | myproposal[PROPOSAL_COMP_ALGS_STOC] = "zlib,none"; |
94ec8c6b | 99 | } else { |
b2552997 | 100 | myproposal[PROPOSAL_COMP_ALGS_CTOS] = |
713f6cd9 | 101 | myproposal[PROPOSAL_COMP_ALGS_STOC] = "none,zlib"; |
94ec8c6b | 102 | } |
b2552997 | 103 | if (options.macs != NULL) { |
104 | myproposal[PROPOSAL_MAC_ALGS_CTOS] = | |
105 | myproposal[PROPOSAL_MAC_ALGS_STOC] = options.macs; | |
106 | } | |
e961a8f9 | 107 | if (options.hostkeyalgorithms != NULL) |
184eed6a | 108 | myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = |
e961a8f9 | 109 | options.hostkeyalgorithms; |
94ec8c6b | 110 | |
ffd7b36b | 111 | if (options.rekey_limit) |
112 | packet_set_rekey_limit(options.rekey_limit); | |
113 | ||
7a37c112 | 114 | /* start key exchange */ |
d8ee838b | 115 | kex = kex_setup(myproposal); |
98a58eda | 116 | kex->kex[KEX_DH_GRP1_SHA1] = kexdh_client; |
117 | kex->kex[KEX_DH_GEX_SHA1] = kexgex_client; | |
a5c9ffdb | 118 | kex->client_version_string=client_version_string; |
119 | kex->server_version_string=server_version_string; | |
f49bc4f7 | 120 | kex->verify_host_key=&verify_host_key_callback; |
94ec8c6b | 121 | |
e092ce67 | 122 | xxx_kex = kex; |
123 | ||
c422989b | 124 | dispatch_run(DISPATCH_BLOCK, &kex->done, kex); |
94ec8c6b | 125 | |
d1ac6175 | 126 | session_id2 = kex->session_id; |
127 | session_id2_len = kex->session_id_len; | |
128 | ||
94ec8c6b | 129 | #ifdef DEBUG_KEXDH |
130 | /* send 1st encrypted/maced/compressed message */ | |
131 | packet_start(SSH2_MSG_IGNORE); | |
132 | packet_put_cstring("markus"); | |
133 | packet_send(); | |
134 | packet_write_wait(); | |
135 | #endif | |
a306f2dd | 136 | } |
71276795 | 137 | |
a306f2dd | 138 | /* |
139 | * Authenticate user | |
140 | */ | |
188adeb2 | 141 | |
142 | typedef struct Authctxt Authctxt; | |
143 | typedef struct Authmethod Authmethod; | |
144 | ||
145 | typedef int sign_cb_fn( | |
146 | Authctxt *authctxt, Key *key, | |
c66f9d0e | 147 | u_char **sigp, u_int *lenp, u_char *data, u_int datalen); |
188adeb2 | 148 | |
149 | struct Authctxt { | |
150 | const char *server_user; | |
8002af61 | 151 | const char *local_user; |
188adeb2 | 152 | const char *host; |
153 | const char *service; | |
188adeb2 | 154 | Authmethod *method; |
94ec8c6b | 155 | int success; |
fee56204 | 156 | char *authlist; |
8002af61 | 157 | /* pubkey */ |
fee56204 | 158 | Key *last_key; |
159 | sign_cb_fn *last_key_sign; | |
160 | int last_key_hint; | |
8002af61 | 161 | AuthenticationConnection *agent; |
162 | /* hostbased */ | |
39c00dc2 | 163 | Sensitive *sensitive; |
6b759005 | 164 | /* kbd-interactive */ |
165 | int info_req_seen; | |
188adeb2 | 166 | }; |
167 | struct Authmethod { | |
168 | char *name; /* string to compare against server's list */ | |
169 | int (*userauth)(Authctxt *authctxt); | |
170 | int *enabled; /* flag in option struct that enables method */ | |
171 | int *batch_flag; /* flag in option struct that disables method */ | |
172 | }; | |
173 | ||
7819b5c3 | 174 | void input_userauth_success(int, u_int32_t, void *); |
175 | void input_userauth_failure(int, u_int32_t, void *); | |
176 | void input_userauth_banner(int, u_int32_t, void *); | |
177 | void input_userauth_error(int, u_int32_t, void *); | |
178 | void input_userauth_info_req(int, u_int32_t, void *); | |
179 | void input_userauth_pk_ok(int, u_int32_t, void *); | |
67ec167d | 180 | void input_userauth_passwd_changereq(int, u_int32_t, void *); |
94ec8c6b | 181 | |
d5bb9418 | 182 | int userauth_none(Authctxt *); |
183 | int userauth_pubkey(Authctxt *); | |
184 | int userauth_passwd(Authctxt *); | |
185 | int userauth_kbdint(Authctxt *); | |
186 | int userauth_hostbased(Authctxt *); | |
188adeb2 | 187 | |
d5bb9418 | 188 | void userauth(Authctxt *, char *); |
fee56204 | 189 | |
396c147e | 190 | static int sign_and_send_pubkey(Authctxt *, Key *, sign_cb_fn *); |
191 | static void clear_auth_state(Authctxt *); | |
fee56204 | 192 | |
396c147e | 193 | static Authmethod *authmethod_get(char *authlist); |
194 | static Authmethod *authmethod_lookup(const char *name); | |
195 | static char *authmethods_get(void); | |
188adeb2 | 196 | |
197 | Authmethod authmethods[] = { | |
3398dda9 | 198 | {"hostbased", |
199 | userauth_hostbased, | |
200 | &options.hostbased_authentication, | |
201 | NULL}, | |
9f37c0af | 202 | {"publickey", |
203 | userauth_pubkey, | |
204 | &options.pubkey_authentication, | |
205 | NULL}, | |
94ec8c6b | 206 | {"keyboard-interactive", |
207 | userauth_kbdint, | |
208 | &options.kbd_interactive_authentication, | |
209 | &options.batch_mode}, | |
9f37c0af | 210 | {"password", |
211 | userauth_passwd, | |
212 | &options.password_authentication, | |
213 | &options.batch_mode}, | |
94ec8c6b | 214 | {"none", |
215 | userauth_none, | |
216 | NULL, | |
217 | NULL}, | |
188adeb2 | 218 | {NULL, NULL, NULL, NULL} |
219 | }; | |
220 | ||
221 | void | |
8002af61 | 222 | ssh_userauth2(const char *local_user, const char *server_user, char *host, |
39c00dc2 | 223 | Sensitive *sensitive) |
188adeb2 | 224 | { |
225 | Authctxt authctxt; | |
226 | int type; | |
188adeb2 | 227 | |
5ba55ada | 228 | if (options.challenge_response_authentication) |
d464095c | 229 | options.kbd_interactive_authentication = 1; |
230 | ||
188adeb2 | 231 | packet_start(SSH2_MSG_SERVICE_REQUEST); |
232 | packet_put_cstring("ssh-userauth"); | |
233 | packet_send(); | |
a77673cc | 234 | debug("SSH2_MSG_SERVICE_REQUEST sent"); |
188adeb2 | 235 | packet_write_wait(); |
54a5250f | 236 | type = packet_read(); |
a77673cc | 237 | if (type != SSH2_MSG_SERVICE_ACCEPT) |
238 | fatal("Server denied authentication request: %d", type); | |
188adeb2 | 239 | if (packet_remaining() > 0) { |
54a5250f | 240 | char *reply = packet_get_string(NULL); |
a77673cc | 241 | debug2("service_accept: %s", reply); |
188adeb2 | 242 | xfree(reply); |
188adeb2 | 243 | } else { |
6226a8f8 | 244 | debug2("buggy server: service_accept w/o service"); |
188adeb2 | 245 | } |
95500969 | 246 | packet_check_eom(); |
a77673cc | 247 | debug("SSH2_MSG_SERVICE_ACCEPT received"); |
188adeb2 | 248 | |
cab80f75 | 249 | if (options.preferred_authentications == NULL) |
250 | options.preferred_authentications = authmethods_get(); | |
251 | ||
188adeb2 | 252 | /* setup authentication context */ |
6b759005 | 253 | memset(&authctxt, 0, sizeof(authctxt)); |
188adeb2 | 254 | authctxt.agent = ssh_get_authentication_connection(); |
255 | authctxt.server_user = server_user; | |
8002af61 | 256 | authctxt.local_user = local_user; |
188adeb2 | 257 | authctxt.host = host; |
258 | authctxt.service = "ssh-connection"; /* service name */ | |
259 | authctxt.success = 0; | |
94ec8c6b | 260 | authctxt.method = authmethod_lookup("none"); |
fee56204 | 261 | authctxt.authlist = NULL; |
39c00dc2 | 262 | authctxt.sensitive = sensitive; |
6b759005 | 263 | authctxt.info_req_seen = 0; |
94ec8c6b | 264 | if (authctxt.method == NULL) |
265 | fatal("ssh_userauth2: internal error: cannot send userauth none request"); | |
188adeb2 | 266 | |
267 | /* initial userauth request */ | |
94ec8c6b | 268 | userauth_none(&authctxt); |
188adeb2 | 269 | |
7a37c112 | 270 | dispatch_init(&input_userauth_error); |
188adeb2 | 271 | dispatch_set(SSH2_MSG_USERAUTH_SUCCESS, &input_userauth_success); |
272 | dispatch_set(SSH2_MSG_USERAUTH_FAILURE, &input_userauth_failure); | |
9616313f | 273 | dispatch_set(SSH2_MSG_USERAUTH_BANNER, &input_userauth_banner); |
188adeb2 | 274 | dispatch_run(DISPATCH_BLOCK, &authctxt.success, &authctxt); /* loop until success */ |
275 | ||
276 | if (authctxt.agent != NULL) | |
277 | ssh_close_authentication_connection(authctxt.agent); | |
278 | ||
6226a8f8 | 279 | debug("Authentication succeeded (%s).", authctxt.method->name); |
188adeb2 | 280 | } |
281 | void | |
fee56204 | 282 | userauth(Authctxt *authctxt, char *authlist) |
283 | { | |
284 | if (authlist == NULL) { | |
285 | authlist = authctxt->authlist; | |
286 | } else { | |
287 | if (authctxt->authlist) | |
288 | xfree(authctxt->authlist); | |
289 | authctxt->authlist = authlist; | |
290 | } | |
291 | for (;;) { | |
292 | Authmethod *method = authmethod_get(authlist); | |
293 | if (method == NULL) | |
294 | fatal("Permission denied (%s).", authlist); | |
295 | authctxt->method = method; | |
296 | if (method->userauth(authctxt) != 0) { | |
297 | debug2("we sent a %s packet, wait for reply", method->name); | |
298 | break; | |
299 | } else { | |
300 | debug2("we did not send a packet, disable method"); | |
301 | method->enabled = NULL; | |
302 | } | |
303 | } | |
304 | } | |
d6133f43 | 305 | |
fee56204 | 306 | void |
7819b5c3 | 307 | input_userauth_error(int type, u_int32_t seq, void *ctxt) |
188adeb2 | 308 | { |
9616313f | 309 | fatal("input_userauth_error: bad message during authentication: " |
310 | "type %d", type); | |
311 | } | |
d6133f43 | 312 | |
9616313f | 313 | void |
7819b5c3 | 314 | input_userauth_banner(int type, u_int32_t seq, void *ctxt) |
9616313f | 315 | { |
316 | char *msg, *lang; | |
317 | debug3("input_userauth_banner"); | |
318 | msg = packet_get_string(NULL); | |
319 | lang = packet_get_string(NULL); | |
320 | fprintf(stderr, "%s", msg); | |
321 | xfree(msg); | |
322 | xfree(lang); | |
188adeb2 | 323 | } |
d6133f43 | 324 | |
188adeb2 | 325 | void |
7819b5c3 | 326 | input_userauth_success(int type, u_int32_t seq, void *ctxt) |
188adeb2 | 327 | { |
328 | Authctxt *authctxt = ctxt; | |
329 | if (authctxt == NULL) | |
330 | fatal("input_userauth_success: no authentication context"); | |
fee56204 | 331 | if (authctxt->authlist) |
332 | xfree(authctxt->authlist); | |
333 | clear_auth_state(authctxt); | |
188adeb2 | 334 | authctxt->success = 1; /* break out */ |
335 | } | |
d6133f43 | 336 | |
188adeb2 | 337 | void |
7819b5c3 | 338 | input_userauth_failure(int type, u_int32_t seq, void *ctxt) |
188adeb2 | 339 | { |
188adeb2 | 340 | Authctxt *authctxt = ctxt; |
341 | char *authlist = NULL; | |
342 | int partial; | |
188adeb2 | 343 | |
344 | if (authctxt == NULL) | |
345 | fatal("input_userauth_failure: no authentication context"); | |
346 | ||
94ec8c6b | 347 | authlist = packet_get_string(NULL); |
188adeb2 | 348 | partial = packet_get_char(); |
95500969 | 349 | packet_check_eom(); |
188adeb2 | 350 | |
351 | if (partial != 0) | |
bbe88b6d | 352 | logit("Authenticated with partial success."); |
6226a8f8 | 353 | debug("Authentications that can continue: %s", authlist); |
188adeb2 | 354 | |
fee56204 | 355 | clear_auth_state(authctxt); |
356 | userauth(authctxt, authlist); | |
357 | } | |
358 | void | |
7819b5c3 | 359 | input_userauth_pk_ok(int type, u_int32_t seq, void *ctxt) |
fee56204 | 360 | { |
361 | Authctxt *authctxt = ctxt; | |
362 | Key *key = NULL; | |
363 | Buffer b; | |
c66f9d0e | 364 | int pktype, sent = 0; |
365 | u_int alen, blen; | |
366 | char *pkalg, *fp; | |
367 | u_char *pkblob; | |
fee56204 | 368 | |
369 | if (authctxt == NULL) | |
370 | fatal("input_userauth_pk_ok: no authentication context"); | |
371 | if (datafellows & SSH_BUG_PKOK) { | |
372 | /* this is similar to SSH_BUG_PKAUTH */ | |
373 | debug2("input_userauth_pk_ok: SSH_BUG_PKOK"); | |
374 | pkblob = packet_get_string(&blen); | |
375 | buffer_init(&b); | |
376 | buffer_append(&b, pkblob, blen); | |
377 | pkalg = buffer_get_string(&b, &alen); | |
378 | buffer_free(&b); | |
379 | } else { | |
380 | pkalg = packet_get_string(&alen); | |
381 | pkblob = packet_get_string(&blen); | |
382 | } | |
95500969 | 383 | packet_check_eom(); |
fee56204 | 384 | |
6226a8f8 | 385 | debug("Server accepts key: pkalg %s blen %u lastkey %p hint %d", |
fee56204 | 386 | pkalg, blen, authctxt->last_key, authctxt->last_key_hint); |
387 | ||
388 | do { | |
389 | if (authctxt->last_key == NULL || | |
390 | authctxt->last_key_sign == NULL) { | |
391 | debug("no last key or no sign cb"); | |
188adeb2 | 392 | break; |
188adeb2 | 393 | } |
0dbdc37c | 394 | if ((pktype = key_type_from_name(pkalg)) == KEY_UNSPEC) { |
fee56204 | 395 | debug("unknown pkalg %s", pkalg); |
396 | break; | |
397 | } | |
398 | if ((key = key_from_blob(pkblob, blen)) == NULL) { | |
399 | debug("no key from blob. pkalg %s", pkalg); | |
400 | break; | |
401 | } | |
762715ce | 402 | if (key->type != pktype) { |
0dbdc37c | 403 | error("input_userauth_pk_ok: type mismatch " |
404 | "for decoded key (received %d, expected %d)", | |
7203d6bb | 405 | key->type, pktype); |
0dbdc37c | 406 | break; |
407 | } | |
22138a36 | 408 | fp = key_fingerprint(key, SSH_FP_MD5, SSH_FP_HEX); |
409 | debug2("input_userauth_pk_ok: fp %s", fp); | |
410 | xfree(fp); | |
fee56204 | 411 | if (!key_equal(key, authctxt->last_key)) { |
412 | debug("key != last_key"); | |
413 | break; | |
414 | } | |
415 | sent = sign_and_send_pubkey(authctxt, key, | |
416 | authctxt->last_key_sign); | |
6aacefa7 | 417 | } while (0); |
fee56204 | 418 | |
419 | if (key != NULL) | |
420 | key_free(key); | |
421 | xfree(pkalg); | |
422 | xfree(pkblob); | |
423 | ||
424 | /* unregister */ | |
425 | clear_auth_state(authctxt); | |
426 | dispatch_set(SSH2_MSG_USERAUTH_PK_OK, NULL); | |
427 | ||
343288b8 | 428 | /* try another method if we did not send a packet */ |
fee56204 | 429 | if (sent == 0) |
430 | userauth(authctxt, NULL); | |
431 | ||
188adeb2 | 432 | } |
433 | ||
94ec8c6b | 434 | int |
435 | userauth_none(Authctxt *authctxt) | |
436 | { | |
437 | /* initial userauth request */ | |
438 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
439 | packet_put_cstring(authctxt->server_user); | |
440 | packet_put_cstring(authctxt->service); | |
441 | packet_put_cstring(authctxt->method->name); | |
442 | packet_send(); | |
94ec8c6b | 443 | return 1; |
444 | } | |
445 | ||
a306f2dd | 446 | int |
188adeb2 | 447 | userauth_passwd(Authctxt *authctxt) |
a306f2dd | 448 | { |
1d1ffb87 | 449 | static int attempt = 0; |
67ec167d | 450 | char prompt[150]; |
a306f2dd | 451 | char *password; |
452 | ||
fa649821 | 453 | if (attempt++ >= options.number_of_password_prompts) |
1d1ffb87 | 454 | return 0; |
455 | ||
6aacefa7 | 456 | if (attempt != 1) |
fa649821 | 457 | error("Permission denied, please try again."); |
458 | ||
f72e01a5 | 459 | snprintf(prompt, sizeof(prompt), "%.30s@%.128s's password: ", |
188adeb2 | 460 | authctxt->server_user, authctxt->host); |
a306f2dd | 461 | password = read_passphrase(prompt, 0); |
462 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
188adeb2 | 463 | packet_put_cstring(authctxt->server_user); |
464 | packet_put_cstring(authctxt->service); | |
94ec8c6b | 465 | packet_put_cstring(authctxt->method->name); |
a306f2dd | 466 | packet_put_char(0); |
a6215e53 | 467 | packet_put_cstring(password); |
a306f2dd | 468 | memset(password, 0, strlen(password)); |
469 | xfree(password); | |
b4b701be | 470 | packet_add_padding(64); |
a306f2dd | 471 | packet_send(); |
67ec167d | 472 | |
7203d6bb | 473 | dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, |
67ec167d | 474 | &input_userauth_passwd_changereq); |
475 | ||
a306f2dd | 476 | return 1; |
477 | } | |
67ec167d | 478 | /* |
479 | * parse PASSWD_CHANGEREQ, prompt user and send SSH2_MSG_USERAUTH_REQUEST | |
480 | */ | |
481 | void | |
ef077e37 | 482 | input_userauth_passwd_changereq(int type, u_int32_t seqnr, void *ctxt) |
67ec167d | 483 | { |
484 | Authctxt *authctxt = ctxt; | |
485 | char *info, *lang, *password = NULL, *retype = NULL; | |
486 | char prompt[150]; | |
487 | ||
488 | debug2("input_userauth_passwd_changereq"); | |
489 | ||
490 | if (authctxt == NULL) | |
491 | fatal("input_userauth_passwd_changereq: " | |
492 | "no authentication context"); | |
493 | ||
494 | info = packet_get_string(NULL); | |
495 | lang = packet_get_string(NULL); | |
496 | if (strlen(info) > 0) | |
bbe88b6d | 497 | logit("%s", info); |
67ec167d | 498 | xfree(info); |
499 | xfree(lang); | |
500 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
501 | packet_put_cstring(authctxt->server_user); | |
502 | packet_put_cstring(authctxt->service); | |
503 | packet_put_cstring(authctxt->method->name); | |
504 | packet_put_char(1); /* additional info */ | |
7203d6bb | 505 | snprintf(prompt, sizeof(prompt), |
67ec167d | 506 | "Enter %.30s@%.128s's old password: ", |
507 | authctxt->server_user, authctxt->host); | |
508 | password = read_passphrase(prompt, 0); | |
509 | packet_put_cstring(password); | |
510 | memset(password, 0, strlen(password)); | |
511 | xfree(password); | |
512 | password = NULL; | |
513 | while (password == NULL) { | |
7203d6bb | 514 | snprintf(prompt, sizeof(prompt), |
67ec167d | 515 | "Enter %.30s@%.128s's new password: ", |
516 | authctxt->server_user, authctxt->host); | |
517 | password = read_passphrase(prompt, RP_ALLOW_EOF); | |
518 | if (password == NULL) { | |
519 | /* bail out */ | |
520 | return; | |
521 | } | |
7203d6bb | 522 | snprintf(prompt, sizeof(prompt), |
67ec167d | 523 | "Retype %.30s@%.128s's new password: ", |
524 | authctxt->server_user, authctxt->host); | |
525 | retype = read_passphrase(prompt, 0); | |
526 | if (strcmp(password, retype) != 0) { | |
527 | memset(password, 0, strlen(password)); | |
528 | xfree(password); | |
bbe88b6d | 529 | logit("Mismatch; try again, EOF to quit."); |
67ec167d | 530 | password = NULL; |
531 | } | |
532 | memset(retype, 0, strlen(retype)); | |
533 | xfree(retype); | |
534 | } | |
535 | packet_put_cstring(password); | |
536 | memset(password, 0, strlen(password)); | |
537 | xfree(password); | |
538 | packet_add_padding(64); | |
539 | packet_send(); | |
7203d6bb | 540 | |
541 | dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, | |
67ec167d | 542 | &input_userauth_passwd_changereq); |
543 | } | |
a306f2dd | 544 | |
ffb215be | 545 | static void |
fee56204 | 546 | clear_auth_state(Authctxt *authctxt) |
547 | { | |
548 | /* XXX clear authentication state */ | |
67ec167d | 549 | dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, NULL); |
550 | ||
fee56204 | 551 | if (authctxt->last_key != NULL && authctxt->last_key_hint == -1) { |
552 | debug3("clear_auth_state: key_free %p", authctxt->last_key); | |
553 | key_free(authctxt->last_key); | |
554 | } | |
555 | authctxt->last_key = NULL; | |
556 | authctxt->last_key_hint = -2; | |
557 | authctxt->last_key_sign = NULL; | |
558 | } | |
559 | ||
396c147e | 560 | static int |
188adeb2 | 561 | sign_and_send_pubkey(Authctxt *authctxt, Key *k, sign_cb_fn *sign_callback) |
a306f2dd | 562 | { |
563 | Buffer b; | |
1e3b8b07 | 564 | u_char *blob, *signature; |
c66f9d0e | 565 | u_int bloblen, slen; |
74fc9186 | 566 | int skip = 0; |
2e73a022 | 567 | int ret = -1; |
94ec8c6b | 568 | int have_sig = 1; |
a306f2dd | 569 | |
cbc5abf9 | 570 | debug3("sign_and_send_pubkey"); |
fee56204 | 571 | |
fa08c86b | 572 | if (key_to_blob(k, &blob, &bloblen) == 0) { |
573 | /* we cannot handle this key */ | |
cbc5abf9 | 574 | debug3("sign_and_send_pubkey: cannot handle key"); |
fa08c86b | 575 | return 0; |
576 | } | |
a306f2dd | 577 | /* data to be signed */ |
578 | buffer_init(&b); | |
33de75a3 | 579 | if (datafellows & SSH_OLD_SESSIONID) { |
74fc9186 | 580 | buffer_append(&b, session_id2, session_id2_len); |
2b87da3b | 581 | skip = session_id2_len; |
33de75a3 | 582 | } else { |
583 | buffer_put_string(&b, session_id2, session_id2_len); | |
584 | skip = buffer_len(&b); | |
74fc9186 | 585 | } |
a306f2dd | 586 | buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST); |
188adeb2 | 587 | buffer_put_cstring(&b, authctxt->server_user); |
d0c832f3 | 588 | buffer_put_cstring(&b, |
cbc5abf9 | 589 | datafellows & SSH_BUG_PKSERVICE ? |
d0c832f3 | 590 | "ssh-userauth" : |
188adeb2 | 591 | authctxt->service); |
cbc5abf9 | 592 | if (datafellows & SSH_BUG_PKAUTH) { |
593 | buffer_put_char(&b, have_sig); | |
594 | } else { | |
595 | buffer_put_cstring(&b, authctxt->method->name); | |
596 | buffer_put_char(&b, have_sig); | |
2b87da3b | 597 | buffer_put_cstring(&b, key_ssh_name(k)); |
cbc5abf9 | 598 | } |
a306f2dd | 599 | buffer_put_string(&b, blob, bloblen); |
a306f2dd | 600 | |
601 | /* generate signature */ | |
fee56204 | 602 | ret = (*sign_callback)(authctxt, k, &signature, &slen, |
603 | buffer_ptr(&b), buffer_len(&b)); | |
2e73a022 | 604 | if (ret == -1) { |
605 | xfree(blob); | |
606 | buffer_free(&b); | |
607 | return 0; | |
608 | } | |
fa08c86b | 609 | #ifdef DEBUG_PK |
a306f2dd | 610 | buffer_dump(&b); |
611 | #endif | |
cbc5abf9 | 612 | if (datafellows & SSH_BUG_PKSERVICE) { |
d0c832f3 | 613 | buffer_clear(&b); |
614 | buffer_append(&b, session_id2, session_id2_len); | |
fee56204 | 615 | skip = session_id2_len; |
d0c832f3 | 616 | buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST); |
188adeb2 | 617 | buffer_put_cstring(&b, authctxt->server_user); |
618 | buffer_put_cstring(&b, authctxt->service); | |
94ec8c6b | 619 | buffer_put_cstring(&b, authctxt->method->name); |
620 | buffer_put_char(&b, have_sig); | |
cbc5abf9 | 621 | if (!(datafellows & SSH_BUG_PKAUTH)) |
2b87da3b | 622 | buffer_put_cstring(&b, key_ssh_name(k)); |
d0c832f3 | 623 | buffer_put_string(&b, blob, bloblen); |
624 | } | |
625 | xfree(blob); | |
fee56204 | 626 | |
a306f2dd | 627 | /* append signature */ |
628 | buffer_put_string(&b, signature, slen); | |
629 | xfree(signature); | |
630 | ||
631 | /* skip session id and packet type */ | |
74fc9186 | 632 | if (buffer_len(&b) < skip + 1) |
188adeb2 | 633 | fatal("userauth_pubkey: internal error"); |
74fc9186 | 634 | buffer_consume(&b, skip + 1); |
a306f2dd | 635 | |
636 | /* put remaining data from buffer into packet */ | |
637 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
638 | packet_put_raw(buffer_ptr(&b), buffer_len(&b)); | |
639 | buffer_free(&b); | |
a306f2dd | 640 | packet_send(); |
2e73a022 | 641 | |
642 | return 1; | |
4c8722d9 | 643 | } |
644 | ||
396c147e | 645 | static int |
fee56204 | 646 | send_pubkey_test(Authctxt *authctxt, Key *k, sign_cb_fn *sign_callback, |
647 | int hint) | |
4c8722d9 | 648 | { |
fee56204 | 649 | u_char *blob; |
21b30f38 | 650 | u_int bloblen, have_sig = 0; |
4c8722d9 | 651 | |
fee56204 | 652 | debug3("send_pubkey_test"); |
653 | ||
654 | if (key_to_blob(k, &blob, &bloblen) == 0) { | |
655 | /* we cannot handle this key */ | |
656 | debug3("send_pubkey_test: cannot handle key"); | |
4c8722d9 | 657 | return 0; |
658 | } | |
fee56204 | 659 | /* register callback for USERAUTH_PK_OK message */ |
660 | authctxt->last_key_sign = sign_callback; | |
661 | authctxt->last_key_hint = hint; | |
662 | authctxt->last_key = k; | |
663 | dispatch_set(SSH2_MSG_USERAUTH_PK_OK, &input_userauth_pk_ok); | |
4c8722d9 | 664 | |
fee56204 | 665 | packet_start(SSH2_MSG_USERAUTH_REQUEST); |
666 | packet_put_cstring(authctxt->server_user); | |
667 | packet_put_cstring(authctxt->service); | |
668 | packet_put_cstring(authctxt->method->name); | |
669 | packet_put_char(have_sig); | |
670 | if (!(datafellows & SSH_BUG_PKAUTH)) | |
671 | packet_put_cstring(key_ssh_name(k)); | |
672 | packet_put_string(blob, bloblen); | |
673 | xfree(blob); | |
674 | packet_send(); | |
675 | return 1; | |
676 | } | |
677 | ||
396c147e | 678 | static Key * |
fee56204 | 679 | load_identity_file(char *filename) |
680 | { | |
681 | Key *private; | |
682 | char prompt[300], *passphrase; | |
aeaa3d9e | 683 | int quit, i; |
d156519a | 684 | struct stat st; |
fee56204 | 685 | |
d156519a | 686 | if (stat(filename, &st) < 0) { |
687 | debug3("no such identity: %s", filename); | |
688 | return NULL; | |
689 | } | |
aeaa3d9e | 690 | private = key_load_private_type(KEY_UNSPEC, filename, "", NULL); |
691 | if (private == NULL) { | |
692 | if (options.batch_mode) | |
fee56204 | 693 | return NULL; |
4c8722d9 | 694 | snprintf(prompt, sizeof prompt, |
184eed6a | 695 | "Enter passphrase for key '%.100s': ", filename); |
188adeb2 | 696 | for (i = 0; i < options.number_of_password_prompts; i++) { |
697 | passphrase = read_passphrase(prompt, 0); | |
698 | if (strcmp(passphrase, "") != 0) { | |
aeaa3d9e | 699 | private = key_load_private_type(KEY_UNSPEC, filename, |
700 | passphrase, NULL); | |
fee56204 | 701 | quit = 0; |
188adeb2 | 702 | } else { |
703 | debug2("no passphrase given, try next key"); | |
fee56204 | 704 | quit = 1; |
188adeb2 | 705 | } |
706 | memset(passphrase, 0, strlen(passphrase)); | |
707 | xfree(passphrase); | |
aeaa3d9e | 708 | if (private != NULL || quit) |
188adeb2 | 709 | break; |
710 | debug2("bad passphrase given, try again..."); | |
711 | } | |
4c8722d9 | 712 | } |
fee56204 | 713 | return private; |
714 | } | |
715 | ||
396c147e | 716 | static int |
c66f9d0e | 717 | identity_sign_cb(Authctxt *authctxt, Key *key, u_char **sigp, u_int *lenp, |
718 | u_char *data, u_int datalen) | |
fee56204 | 719 | { |
720 | Key *private; | |
721 | int idx, ret; | |
722 | ||
723 | idx = authctxt->last_key_hint; | |
724 | if (idx < 0) | |
725 | return -1; | |
383546c4 | 726 | |
727 | /* private key is stored in external hardware */ | |
184eed6a | 728 | if (options.identity_keys[idx]->flags & KEY_FLAG_EXT) |
383546c4 | 729 | return key_sign(options.identity_keys[idx], sigp, lenp, data, datalen); |
730 | ||
fee56204 | 731 | private = load_identity_file(options.identity_files[idx]); |
732 | if (private == NULL) | |
733 | return -1; | |
734 | ret = key_sign(private, sigp, lenp, data, datalen); | |
735 | key_free(private); | |
2e73a022 | 736 | return ret; |
737 | } | |
738 | ||
396c147e | 739 | static int |
c66f9d0e | 740 | agent_sign_cb(Authctxt *authctxt, Key *key, u_char **sigp, u_int *lenp, |
741 | u_char *data, u_int datalen) | |
2e73a022 | 742 | { |
188adeb2 | 743 | return ssh_agent_sign(authctxt->agent, key, sigp, lenp, data, datalen); |
2e73a022 | 744 | } |
745 | ||
396c147e | 746 | static int |
c66f9d0e | 747 | key_sign_cb(Authctxt *authctxt, Key *key, u_char **sigp, u_int *lenp, |
748 | u_char *data, u_int datalen) | |
fee56204 | 749 | { |
cd332296 | 750 | return key_sign(key, sigp, lenp, data, datalen); |
fee56204 | 751 | } |
752 | ||
396c147e | 753 | static int |
188adeb2 | 754 | userauth_pubkey_agent(Authctxt *authctxt) |
2e73a022 | 755 | { |
756 | static int called = 0; | |
fa08c86b | 757 | int ret = 0; |
2e73a022 | 758 | char *comment; |
759 | Key *k; | |
2e73a022 | 760 | |
761 | if (called == 0) { | |
fa08c86b | 762 | if (ssh_get_num_identities(authctxt->agent, 2) == 0) |
763 | debug2("userauth_pubkey_agent: no keys at all"); | |
188adeb2 | 764 | called = 1; |
2e73a022 | 765 | } |
fa08c86b | 766 | k = ssh_get_next_identity(authctxt->agent, &comment, 2); |
188adeb2 | 767 | if (k == NULL) { |
fa08c86b | 768 | debug2("userauth_pubkey_agent: no more keys"); |
769 | } else { | |
6226a8f8 | 770 | debug("Offering agent key: %s", comment); |
fa08c86b | 771 | xfree(comment); |
fee56204 | 772 | ret = send_pubkey_test(authctxt, k, agent_sign_cb, -1); |
773 | if (ret == 0) | |
774 | key_free(k); | |
188adeb2 | 775 | } |
fa08c86b | 776 | if (ret == 0) |
777 | debug2("userauth_pubkey_agent: no message sent"); | |
2e73a022 | 778 | return ret; |
a306f2dd | 779 | } |
780 | ||
188adeb2 | 781 | int |
782 | userauth_pubkey(Authctxt *authctxt) | |
a306f2dd | 783 | { |
188adeb2 | 784 | static int idx = 0; |
785 | int sent = 0; | |
fee56204 | 786 | Key *key; |
787 | char *filename; | |
188adeb2 | 788 | |
fa08c86b | 789 | if (authctxt->agent != NULL) { |
790 | do { | |
791 | sent = userauth_pubkey_agent(authctxt); | |
6aacefa7 | 792 | } while (!sent && authctxt->agent->howmany > 0); |
fa08c86b | 793 | } |
794 | while (!sent && idx < options.num_identity_files) { | |
fee56204 | 795 | key = options.identity_keys[idx]; |
796 | filename = options.identity_files[idx]; | |
797 | if (key == NULL) { | |
6226a8f8 | 798 | debug("Trying private key: %s", filename); |
fee56204 | 799 | key = load_identity_file(filename); |
800 | if (key != NULL) { | |
801 | sent = sign_and_send_pubkey(authctxt, key, | |
802 | key_sign_cb); | |
803 | key_free(key); | |
804 | } | |
805 | } else if (key->type != KEY_RSA1) { | |
6226a8f8 | 806 | debug("Offering public key: %s", filename); |
fee56204 | 807 | sent = send_pubkey_test(authctxt, key, |
808 | identity_sign_cb, idx); | |
809 | } | |
fa08c86b | 810 | idx++; |
811 | } | |
188adeb2 | 812 | return sent; |
813 | } | |
a306f2dd | 814 | |
94ec8c6b | 815 | /* |
816 | * Send userauth request message specifying keyboard-interactive method. | |
817 | */ | |
818 | int | |
819 | userauth_kbdint(Authctxt *authctxt) | |
820 | { | |
821 | static int attempt = 0; | |
822 | ||
823 | if (attempt++ >= options.number_of_password_prompts) | |
824 | return 0; | |
6b759005 | 825 | /* disable if no SSH2_MSG_USERAUTH_INFO_REQUEST has been seen */ |
826 | if (attempt > 1 && !authctxt->info_req_seen) { | |
827 | debug3("userauth_kbdint: disable: no info_req_seen"); | |
828 | dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, NULL); | |
829 | return 0; | |
830 | } | |
94ec8c6b | 831 | |
832 | debug2("userauth_kbdint"); | |
833 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
834 | packet_put_cstring(authctxt->server_user); | |
835 | packet_put_cstring(authctxt->service); | |
836 | packet_put_cstring(authctxt->method->name); | |
837 | packet_put_cstring(""); /* lang */ | |
838 | packet_put_cstring(options.kbd_interactive_devices ? | |
839 | options.kbd_interactive_devices : ""); | |
840 | packet_send(); | |
94ec8c6b | 841 | |
842 | dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, &input_userauth_info_req); | |
843 | return 1; | |
844 | } | |
845 | ||
846 | /* | |
f72e01a5 | 847 | * parse INFO_REQUEST, prompt user and send INFO_RESPONSE |
94ec8c6b | 848 | */ |
849 | void | |
7819b5c3 | 850 | input_userauth_info_req(int type, u_int32_t seq, void *ctxt) |
94ec8c6b | 851 | { |
852 | Authctxt *authctxt = ctxt; | |
f72e01a5 | 853 | char *name, *inst, *lang, *prompt, *response; |
1e3b8b07 | 854 | u_int num_prompts, i; |
94ec8c6b | 855 | int echo = 0; |
856 | ||
857 | debug2("input_userauth_info_req"); | |
858 | ||
859 | if (authctxt == NULL) | |
860 | fatal("input_userauth_info_req: no authentication context"); | |
861 | ||
6b759005 | 862 | authctxt->info_req_seen = 1; |
863 | ||
94ec8c6b | 864 | name = packet_get_string(NULL); |
865 | inst = packet_get_string(NULL); | |
866 | lang = packet_get_string(NULL); | |
94ec8c6b | 867 | if (strlen(name) > 0) |
bbe88b6d | 868 | logit("%s", name); |
94ec8c6b | 869 | if (strlen(inst) > 0) |
bbe88b6d | 870 | logit("%s", inst); |
f72e01a5 | 871 | xfree(name); |
94ec8c6b | 872 | xfree(inst); |
f72e01a5 | 873 | xfree(lang); |
94ec8c6b | 874 | |
875 | num_prompts = packet_get_int(); | |
876 | /* | |
877 | * Begin to build info response packet based on prompts requested. | |
878 | * We commit to providing the correct number of responses, so if | |
879 | * further on we run into a problem that prevents this, we have to | |
880 | * be sure and clean this up and send a correct error response. | |
881 | */ | |
882 | packet_start(SSH2_MSG_USERAUTH_INFO_RESPONSE); | |
883 | packet_put_int(num_prompts); | |
884 | ||
5ba55ada | 885 | debug2("input_userauth_info_req: num_prompts %d", num_prompts); |
94ec8c6b | 886 | for (i = 0; i < num_prompts; i++) { |
887 | prompt = packet_get_string(NULL); | |
888 | echo = packet_get_char(); | |
889 | ||
1843a425 | 890 | response = read_passphrase(prompt, echo ? RP_ECHO : 0); |
94ec8c6b | 891 | |
a6215e53 | 892 | packet_put_cstring(response); |
94ec8c6b | 893 | memset(response, 0, strlen(response)); |
894 | xfree(response); | |
895 | xfree(prompt); | |
896 | } | |
95500969 | 897 | packet_check_eom(); /* done with parsing incoming message. */ |
94ec8c6b | 898 | |
b4b701be | 899 | packet_add_padding(64); |
94ec8c6b | 900 | packet_send(); |
94ec8c6b | 901 | } |
a306f2dd | 902 | |
39c00dc2 | 903 | static int |
d6133f43 | 904 | ssh_keysign(Key *key, u_char **sigp, u_int *lenp, |
39c00dc2 | 905 | u_char *data, u_int datalen) |
906 | { | |
907 | Buffer b; | |
7091a26b | 908 | struct stat st; |
39c00dc2 | 909 | pid_t pid; |
d4826734 | 910 | int to[2], from[2], status, version = 2; |
39c00dc2 | 911 | |
6226a8f8 | 912 | debug2("ssh_keysign called"); |
39c00dc2 | 913 | |
7091a26b | 914 | if (stat(_PATH_SSH_KEY_SIGN, &st) < 0) { |
915 | error("ssh_keysign: no installed: %s", strerror(errno)); | |
916 | return -1; | |
917 | } | |
39c00dc2 | 918 | if (fflush(stdout) != 0) |
919 | error("ssh_keysign: fflush: %s", strerror(errno)); | |
920 | if (pipe(to) < 0) { | |
921 | error("ssh_keysign: pipe: %s", strerror(errno)); | |
922 | return -1; | |
923 | } | |
924 | if (pipe(from) < 0) { | |
925 | error("ssh_keysign: pipe: %s", strerror(errno)); | |
926 | return -1; | |
927 | } | |
928 | if ((pid = fork()) < 0) { | |
929 | error("ssh_keysign: fork: %s", strerror(errno)); | |
930 | return -1; | |
931 | } | |
932 | if (pid == 0) { | |
933 | seteuid(getuid()); | |
934 | setuid(getuid()); | |
935 | close(from[0]); | |
936 | if (dup2(from[1], STDOUT_FILENO) < 0) | |
937 | fatal("ssh_keysign: dup2: %s", strerror(errno)); | |
938 | close(to[1]); | |
939 | if (dup2(to[0], STDIN_FILENO) < 0) | |
940 | fatal("ssh_keysign: dup2: %s", strerror(errno)); | |
d4826734 | 941 | close(from[1]); |
942 | close(to[0]); | |
a3f69458 | 943 | execl(_PATH_SSH_KEY_SIGN, _PATH_SSH_KEY_SIGN, (char *) 0); |
39c00dc2 | 944 | fatal("ssh_keysign: exec(%s): %s", _PATH_SSH_KEY_SIGN, |
945 | strerror(errno)); | |
946 | } | |
947 | close(from[1]); | |
948 | close(to[0]); | |
949 | ||
950 | buffer_init(&b); | |
d4826734 | 951 | buffer_put_int(&b, packet_get_connection_in()); /* send # of socket */ |
39c00dc2 | 952 | buffer_put_string(&b, data, datalen); |
e987fdbe | 953 | ssh_msg_send(to[1], version, &b); |
39c00dc2 | 954 | |
e987fdbe | 955 | if (ssh_msg_recv(from[0], &b) < 0) { |
7091a26b | 956 | error("ssh_keysign: no reply"); |
39c00dc2 | 957 | buffer_clear(&b); |
958 | return -1; | |
959 | } | |
39c00dc2 | 960 | close(from[0]); |
961 | close(to[1]); | |
962 | ||
d4826734 | 963 | while (waitpid(pid, &status, 0) < 0) |
964 | if (errno != EINTR) | |
965 | break; | |
39c00dc2 | 966 | |
7091a26b | 967 | if (buffer_get_char(&b) != version) { |
968 | error("ssh_keysign: bad version"); | |
969 | buffer_clear(&b); | |
970 | return -1; | |
971 | } | |
972 | *sigp = buffer_get_string(&b, lenp); | |
973 | buffer_clear(&b); | |
974 | ||
39c00dc2 | 975 | return 0; |
976 | } | |
977 | ||
8002af61 | 978 | int |
979 | userauth_hostbased(Authctxt *authctxt) | |
980 | { | |
981 | Key *private = NULL; | |
39c00dc2 | 982 | Sensitive *sensitive = authctxt->sensitive; |
8002af61 | 983 | Buffer b; |
984 | u_char *signature, *blob; | |
985 | char *chost, *pkalg, *p; | |
8dddf799 | 986 | const char *service; |
8002af61 | 987 | u_int blen, slen; |
f98c3421 | 988 | int ok, i, len, found = 0; |
8002af61 | 989 | |
8002af61 | 990 | /* check for a useful key */ |
39c00dc2 | 991 | for (i = 0; i < sensitive->nkeys; i++) { |
992 | private = sensitive->keys[i]; | |
8002af61 | 993 | if (private && private->type != KEY_RSA1) { |
994 | found = 1; | |
995 | /* we take and free the key */ | |
39c00dc2 | 996 | sensitive->keys[i] = NULL; |
8002af61 | 997 | break; |
998 | } | |
999 | } | |
1000 | if (!found) { | |
6226a8f8 | 1001 | debug("No more client hostkeys for hostbased authentication."); |
8002af61 | 1002 | return 0; |
1003 | } | |
1004 | if (key_to_blob(private, &blob, &blen) == 0) { | |
1005 | key_free(private); | |
8002af61 | 1006 | return 0; |
1007 | } | |
e8d59b4d | 1008 | /* figure out a name for the client host */ |
1009 | p = get_local_name(packet_get_connection_in()); | |
1010 | if (p == NULL) { | |
1011 | error("userauth_hostbased: cannot get local ipaddr/name"); | |
1012 | key_free(private); | |
1013 | return 0; | |
1014 | } | |
1015 | len = strlen(p) + 2; | |
1016 | chost = xmalloc(len); | |
1017 | strlcpy(chost, p, len); | |
1018 | strlcat(chost, ".", len); | |
1019 | debug2("userauth_hostbased: chost %s", chost); | |
3e2f2431 | 1020 | xfree(p); |
e8d59b4d | 1021 | |
8dddf799 | 1022 | service = datafellows & SSH_BUG_HBSERVICE ? "ssh-userauth" : |
1023 | authctxt->service; | |
8002af61 | 1024 | pkalg = xstrdup(key_ssh_name(private)); |
1025 | buffer_init(&b); | |
8002af61 | 1026 | /* construct data */ |
8dddf799 | 1027 | buffer_put_string(&b, session_id2, session_id2_len); |
8002af61 | 1028 | buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST); |
1029 | buffer_put_cstring(&b, authctxt->server_user); | |
8dddf799 | 1030 | buffer_put_cstring(&b, service); |
8002af61 | 1031 | buffer_put_cstring(&b, authctxt->method->name); |
1032 | buffer_put_cstring(&b, pkalg); | |
1033 | buffer_put_string(&b, blob, blen); | |
1034 | buffer_put_cstring(&b, chost); | |
1035 | buffer_put_cstring(&b, authctxt->local_user); | |
1036 | #ifdef DEBUG_PK | |
1037 | buffer_dump(&b); | |
1038 | #endif | |
39c00dc2 | 1039 | if (sensitive->external_keysign) |
1040 | ok = ssh_keysign(private, &signature, &slen, | |
1041 | buffer_ptr(&b), buffer_len(&b)); | |
1042 | else | |
1043 | ok = key_sign(private, &signature, &slen, | |
1044 | buffer_ptr(&b), buffer_len(&b)); | |
8002af61 | 1045 | key_free(private); |
1046 | buffer_free(&b); | |
1047 | if (ok != 0) { | |
1048 | error("key_sign failed"); | |
1049 | xfree(chost); | |
1050 | xfree(pkalg); | |
1051 | return 0; | |
1052 | } | |
1053 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
1054 | packet_put_cstring(authctxt->server_user); | |
1055 | packet_put_cstring(authctxt->service); | |
1056 | packet_put_cstring(authctxt->method->name); | |
1057 | packet_put_cstring(pkalg); | |
1058 | packet_put_string(blob, blen); | |
1059 | packet_put_cstring(chost); | |
1060 | packet_put_cstring(authctxt->local_user); | |
1061 | packet_put_string(signature, slen); | |
1062 | memset(signature, 's', slen); | |
1063 | xfree(signature); | |
1064 | xfree(chost); | |
1065 | xfree(pkalg); | |
1066 | ||
1067 | packet_send(); | |
1068 | return 1; | |
1069 | } | |
1070 | ||
188adeb2 | 1071 | /* find auth method */ |
1072 | ||
188adeb2 | 1073 | /* |
1074 | * given auth method name, if configurable options permit this method fill | |
1075 | * in auth_ident field and return true, otherwise return false. | |
1076 | */ | |
396c147e | 1077 | static int |
188adeb2 | 1078 | authmethod_is_enabled(Authmethod *method) |
1079 | { | |
1080 | if (method == NULL) | |
1081 | return 0; | |
1082 | /* return false if options indicate this method is disabled */ | |
1083 | if (method->enabled == NULL || *method->enabled == 0) | |
1084 | return 0; | |
1085 | /* return false if batch mode is enabled but method needs interactive mode */ | |
1086 | if (method->batch_flag != NULL && *method->batch_flag != 0) | |
1087 | return 0; | |
1088 | return 1; | |
1089 | } | |
a306f2dd | 1090 | |
396c147e | 1091 | static Authmethod * |
188adeb2 | 1092 | authmethod_lookup(const char *name) |
1093 | { | |
1094 | Authmethod *method = NULL; | |
1095 | if (name != NULL) | |
1096 | for (method = authmethods; method->name != NULL; method++) | |
1097 | if (strcmp(name, method->name) == 0) | |
1098 | return method; | |
1099 | debug2("Unrecognized authentication method name: %s", name ? name : "NULL"); | |
1100 | return NULL; | |
1101 | } | |
1102 | ||
cab80f75 | 1103 | /* XXX internal state */ |
1104 | static Authmethod *current = NULL; | |
1105 | static char *supported = NULL; | |
1106 | static char *preferred = NULL; | |
d6133f43 | 1107 | |
188adeb2 | 1108 | /* |
1109 | * Given the authentication method list sent by the server, return the | |
1110 | * next method we should try. If the server initially sends a nil list, | |
cd332296 | 1111 | * use a built-in default list. |
2b87da3b | 1112 | */ |
396c147e | 1113 | static Authmethod * |
188adeb2 | 1114 | authmethod_get(char *authlist) |
1115 | { | |
cab80f75 | 1116 | char *name = NULL; |
21b30f38 | 1117 | u_int next; |
2b87da3b | 1118 | |
188adeb2 | 1119 | /* Use a suitable default if we're passed a nil list. */ |
1120 | if (authlist == NULL || strlen(authlist) == 0) | |
cab80f75 | 1121 | authlist = options.preferred_authentications; |
1122 | ||
1123 | if (supported == NULL || strcmp(authlist, supported) != 0) { | |
1124 | debug3("start over, passed a different list %s", authlist); | |
1125 | if (supported != NULL) | |
1126 | xfree(supported); | |
1127 | supported = xstrdup(authlist); | |
1128 | preferred = options.preferred_authentications; | |
1129 | debug3("preferred %s", preferred); | |
1130 | current = NULL; | |
1131 | } else if (current != NULL && authmethod_is_enabled(current)) | |
1132 | return current; | |
188adeb2 | 1133 | |
cab80f75 | 1134 | for (;;) { |
1135 | if ((name = match_list(preferred, supported, &next)) == NULL) { | |
6226a8f8 | 1136 | debug("No more authentication methods to try."); |
cab80f75 | 1137 | current = NULL; |
1138 | return NULL; | |
1139 | } | |
1140 | preferred += next; | |
94ec8c6b | 1141 | debug3("authmethod_lookup %s", name); |
cab80f75 | 1142 | debug3("remaining preferred: %s", preferred); |
1143 | if ((current = authmethod_lookup(name)) != NULL && | |
1144 | authmethod_is_enabled(current)) { | |
94ec8c6b | 1145 | debug3("authmethod_is_enabled %s", name); |
6226a8f8 | 1146 | debug("Next authentication method: %s", name); |
cab80f75 | 1147 | return current; |
94ec8c6b | 1148 | } |
a306f2dd | 1149 | } |
cab80f75 | 1150 | } |
a22aff1f | 1151 | |
ffb215be | 1152 | static char * |
cab80f75 | 1153 | authmethods_get(void) |
1154 | { | |
1155 | Authmethod *method = NULL; | |
3469eac4 | 1156 | Buffer b; |
1157 | char *list; | |
cab80f75 | 1158 | |
3469eac4 | 1159 | buffer_init(&b); |
cab80f75 | 1160 | for (method = authmethods; method->name != NULL; method++) { |
1161 | if (authmethod_is_enabled(method)) { | |
3469eac4 | 1162 | if (buffer_len(&b) > 0) |
1163 | buffer_append(&b, ",", 1); | |
1164 | buffer_append(&b, method->name, strlen(method->name)); | |
cab80f75 | 1165 | } |
1166 | } | |
3469eac4 | 1167 | buffer_append(&b, "\0", 1); |
1168 | list = xstrdup(buffer_ptr(&b)); | |
1169 | buffer_free(&b); | |
1170 | return list; | |
a306f2dd | 1171 | } |