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9108f8d9 | 1 | /* $OpenBSD: sshconnect2.c,v 1.162 2006/08/30 00:06:51 dtucker Exp $ */ |
3c0ef626 | 2 | /* |
3 | * Copyright (c) 2000 Markus Friedl. All rights reserved. | |
4 | * | |
5 | * Redistribution and use in source and binary forms, with or without | |
6 | * modification, are permitted provided that the following conditions | |
7 | * are met: | |
8 | * 1. Redistributions of source code must retain the above copyright | |
9 | * notice, this list of conditions and the following disclaimer. | |
10 | * 2. Redistributions in binary form must reproduce the above copyright | |
11 | * notice, this list of conditions and the following disclaimer in the | |
12 | * documentation and/or other materials provided with the distribution. | |
13 | * | |
14 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR | |
15 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES | |
16 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. | |
17 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, | |
18 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT | |
19 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, | |
20 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY | |
21 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT | |
22 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF | |
23 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | |
24 | */ | |
25 | ||
26 | #include "includes.h" | |
9108f8d9 | 27 | |
28 | #include <sys/types.h> | |
29 | #include <sys/socket.h> | |
30 | #include <sys/wait.h> | |
31 | #include <sys/stat.h> | |
32 | ||
33 | #include <errno.h> | |
34 | #include <pwd.h> | |
35 | #include <signal.h> | |
36 | #include <stdarg.h> | |
37 | #include <stdio.h> | |
38 | #include <string.h> | |
39 | #include <unistd.h> | |
0fff78ff | 40 | |
41 | #include "openbsd-compat/sys-queue.h" | |
3c0ef626 | 42 | |
9108f8d9 | 43 | #include "xmalloc.h" |
3c0ef626 | 44 | #include "ssh.h" |
45 | #include "ssh2.h" | |
3c0ef626 | 46 | #include "buffer.h" |
47 | #include "packet.h" | |
3c0ef626 | 48 | #include "compat.h" |
3c0ef626 | 49 | #include "cipher.h" |
9108f8d9 | 50 | #include "key.h" |
3c0ef626 | 51 | #include "kex.h" |
52 | #include "myproposal.h" | |
3c0ef626 | 53 | #include "sshconnect.h" |
54 | #include "authfile.h" | |
55 | #include "dh.h" | |
56 | #include "authfd.h" | |
57 | #include "log.h" | |
58 | #include "readconf.h" | |
c9f39d2c | 59 | #include "misc.h" |
3c0ef626 | 60 | #include "match.h" |
61 | #include "dispatch.h" | |
62 | #include "canohost.h" | |
f5799ae1 | 63 | #include "msg.h" |
64 | #include "pathnames.h" | |
9108f8d9 | 65 | #include "uidswap.h" |
3c0ef626 | 66 | |
0fff78ff | 67 | #ifdef GSSAPI |
68 | #include "ssh-gss.h" | |
69 | #endif | |
70 | ||
3c0ef626 | 71 | /* import */ |
72 | extern char *client_version_string; | |
73 | extern char *server_version_string; | |
74 | extern Options options; | |
d6f3ca1e | 75 | extern Kex *xxx_kex; |
76 | ||
77 | /* tty_flag is set in ssh.c. use this in ssh_userauth2 */ | |
78 | /* if it is set then prevent the switch to the null cipher */ | |
79 | ||
80 | extern int tty_flag; | |
3c0ef626 | 81 | |
82 | /* | |
83 | * SSH2 key exchange | |
84 | */ | |
85 | ||
86 | u_char *session_id2 = NULL; | |
0fff78ff | 87 | u_int session_id2_len = 0; |
3c0ef626 | 88 | |
89 | char *xxx_host; | |
90 | struct sockaddr *xxx_hostaddr; | |
91 | ||
92 | Kex *xxx_kex = NULL; | |
93 | ||
94 | static int | |
95 | verify_host_key_callback(Key *hostkey) | |
96 | { | |
97 | if (verify_host_key(xxx_host, xxx_hostaddr, hostkey) == -1) | |
98 | fatal("Host key verification failed."); | |
99 | return 0; | |
100 | } | |
101 | ||
102 | void | |
103 | ssh_kex2(char *host, struct sockaddr *hostaddr) | |
104 | { | |
105 | Kex *kex; | |
106 | ||
70e5f740 | 107 | #ifdef GSSAPI |
108 | char *orig = NULL, *gss = NULL; | |
109 | char *gss_host = NULL; | |
110 | #endif | |
111 | ||
3c0ef626 | 112 | xxx_host = host; |
113 | xxx_hostaddr = hostaddr; | |
114 | ||
70e5f740 | 115 | #ifdef GSSAPI |
116 | if (options.gss_keyex) { | |
117 | /* Add the GSSAPI mechanisms currently supported on this | |
118 | * client to the key exchange algorithm proposal */ | |
119 | orig = myproposal[PROPOSAL_KEX_ALGS]; | |
120 | ||
121 | if (options.gss_trust_dns) | |
122 | gss_host = (char *)get_canonical_hostname(1); | |
123 | else | |
124 | gss_host = host; | |
125 | ||
126 | gss = ssh_gssapi_client_mechanisms(gss_host); | |
127 | if (gss) { | |
128 | debug("Offering GSSAPI proposal: %s", gss); | |
129 | xasprintf(&myproposal[PROPOSAL_KEX_ALGS], | |
130 | "%s,%s", gss, orig); | |
131 | } | |
132 | } | |
133 | #endif | |
134 | ||
3c0ef626 | 135 | if (options.ciphers == (char *)-1) { |
0fff78ff | 136 | logit("No valid ciphers for protocol version 2 given, using defaults."); |
3c0ef626 | 137 | options.ciphers = NULL; |
138 | } | |
139 | if (options.ciphers != NULL) { | |
140 | myproposal[PROPOSAL_ENC_ALGS_CTOS] = | |
141 | myproposal[PROPOSAL_ENC_ALGS_STOC] = options.ciphers; | |
d6f3ca1e | 142 | } |
143 | ||
3c0ef626 | 144 | myproposal[PROPOSAL_ENC_ALGS_CTOS] = |
145 | compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_CTOS]); | |
146 | myproposal[PROPOSAL_ENC_ALGS_STOC] = | |
147 | compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_STOC]); | |
148 | if (options.compression) { | |
149 | myproposal[PROPOSAL_COMP_ALGS_CTOS] = | |
665a873d | 150 | myproposal[PROPOSAL_COMP_ALGS_STOC] = "zlib@openssh.com,zlib,none"; |
3c0ef626 | 151 | } else { |
152 | myproposal[PROPOSAL_COMP_ALGS_CTOS] = | |
665a873d | 153 | myproposal[PROPOSAL_COMP_ALGS_STOC] = "none,zlib@openssh.com,zlib"; |
3c0ef626 | 154 | } |
155 | if (options.macs != NULL) { | |
156 | myproposal[PROPOSAL_MAC_ALGS_CTOS] = | |
157 | myproposal[PROPOSAL_MAC_ALGS_STOC] = options.macs; | |
158 | } | |
159 | if (options.hostkeyalgorithms != NULL) | |
e9a17296 | 160 | myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = |
3c0ef626 | 161 | options.hostkeyalgorithms; |
162 | ||
70e5f740 | 163 | #ifdef GSSAPI |
164 | /* If we've got GSSAPI algorithms, then we also support the | |
165 | * 'null' hostkey, as a last resort */ | |
166 | if (options.gss_keyex && gss) { | |
167 | orig = myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS]; | |
168 | xasprintf(&myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS], | |
169 | "%s,null", orig); | |
170 | } | |
171 | #endif | |
172 | ||
0fff78ff | 173 | if (options.rekey_limit) |
174 | packet_set_rekey_limit(options.rekey_limit); | |
175 | ||
3c0ef626 | 176 | /* start key exchange */ |
177 | kex = kex_setup(myproposal); | |
6a9b3198 | 178 | kex->kex[KEX_DH_GRP1_SHA1] = kexdh_client; |
c9f39d2c | 179 | kex->kex[KEX_DH_GRP14_SHA1] = kexdh_client; |
6a9b3198 | 180 | kex->kex[KEX_DH_GEX_SHA1] = kexgex_client; |
9108f8d9 | 181 | kex->kex[KEX_DH_GEX_SHA256] = kexgex_client; |
70e5f740 | 182 | #ifdef GSSAPI |
183 | kex->kex[KEX_GSS_GRP1_SHA1] = kexgss_client; | |
184 | kex->kex[KEX_GSS_GRP14_SHA1] = kexgss_client; | |
185 | kex->kex[KEX_GSS_GEX_SHA1] = kexgss_client; | |
186 | #endif | |
3c0ef626 | 187 | kex->client_version_string=client_version_string; |
188 | kex->server_version_string=server_version_string; | |
189 | kex->verify_host_key=&verify_host_key_callback; | |
190 | ||
70e5f740 | 191 | #ifdef GSSAPI |
192 | kex->gss_deleg_creds = options.gss_deleg_creds; | |
193 | kex->gss_trust_dns = options.gss_trust_dns; | |
194 | kex->gss_host = gss_host; | |
195 | #endif | |
196 | ||
3c0ef626 | 197 | xxx_kex = kex; |
198 | ||
199 | dispatch_run(DISPATCH_BLOCK, &kex->done, kex); | |
200 | ||
201 | session_id2 = kex->session_id; | |
202 | session_id2_len = kex->session_id_len; | |
203 | ||
204 | #ifdef DEBUG_KEXDH | |
205 | /* send 1st encrypted/maced/compressed message */ | |
206 | packet_start(SSH2_MSG_IGNORE); | |
207 | packet_put_cstring("markus"); | |
208 | packet_send(); | |
209 | packet_write_wait(); | |
210 | #endif | |
3c0ef626 | 211 | } |
212 | ||
213 | /* | |
214 | * Authenticate user | |
215 | */ | |
216 | ||
217 | typedef struct Authctxt Authctxt; | |
218 | typedef struct Authmethod Authmethod; | |
0fff78ff | 219 | typedef struct identity Identity; |
220 | typedef struct idlist Idlist; | |
221 | ||
222 | struct identity { | |
223 | TAILQ_ENTRY(identity) next; | |
224 | AuthenticationConnection *ac; /* set if agent supports key */ | |
225 | Key *key; /* public/private key */ | |
226 | char *filename; /* comment for agent-only keys */ | |
227 | int tried; | |
228 | int isprivate; /* key points to the private key */ | |
229 | }; | |
230 | TAILQ_HEAD(idlist, identity); | |
3c0ef626 | 231 | |
232 | struct Authctxt { | |
233 | const char *server_user; | |
234 | const char *local_user; | |
235 | const char *host; | |
236 | const char *service; | |
237 | Authmethod *method; | |
238 | int success; | |
239 | char *authlist; | |
240 | /* pubkey */ | |
0fff78ff | 241 | Idlist keys; |
3c0ef626 | 242 | AuthenticationConnection *agent; |
243 | /* hostbased */ | |
f5799ae1 | 244 | Sensitive *sensitive; |
3c0ef626 | 245 | /* kbd-interactive */ |
246 | int info_req_seen; | |
0fff78ff | 247 | /* generic */ |
248 | void *methoddata; | |
3c0ef626 | 249 | }; |
250 | struct Authmethod { | |
251 | char *name; /* string to compare against server's list */ | |
252 | int (*userauth)(Authctxt *authctxt); | |
253 | int *enabled; /* flag in option struct that enables method */ | |
254 | int *batch_flag; /* flag in option struct that disables method */ | |
255 | }; | |
256 | ||
e9a17296 | 257 | void input_userauth_success(int, u_int32_t, void *); |
258 | void input_userauth_failure(int, u_int32_t, void *); | |
259 | void input_userauth_banner(int, u_int32_t, void *); | |
260 | void input_userauth_error(int, u_int32_t, void *); | |
261 | void input_userauth_info_req(int, u_int32_t, void *); | |
262 | void input_userauth_pk_ok(int, u_int32_t, void *); | |
700318f3 | 263 | void input_userauth_passwd_changereq(int, u_int32_t, void *); |
3c0ef626 | 264 | |
e9a17296 | 265 | int userauth_none(Authctxt *); |
266 | int userauth_pubkey(Authctxt *); | |
267 | int userauth_passwd(Authctxt *); | |
268 | int userauth_kbdint(Authctxt *); | |
269 | int userauth_hostbased(Authctxt *); | |
0fff78ff | 270 | int userauth_kerberos(Authctxt *); |
271 | ||
272 | #ifdef GSSAPI | |
273 | int userauth_gssapi(Authctxt *authctxt); | |
274 | void input_gssapi_response(int type, u_int32_t, void *); | |
275 | void input_gssapi_token(int type, u_int32_t, void *); | |
276 | void input_gssapi_hash(int type, u_int32_t, void *); | |
277 | void input_gssapi_error(int, u_int32_t, void *); | |
278 | void input_gssapi_errtok(int, u_int32_t, void *); | |
70e5f740 | 279 | int userauth_gsskeyex(Authctxt *authctxt); |
0fff78ff | 280 | #endif |
3c0ef626 | 281 | |
e9a17296 | 282 | void userauth(Authctxt *, char *); |
3c0ef626 | 283 | |
0fff78ff | 284 | static int sign_and_send_pubkey(Authctxt *, Identity *); |
285 | static void pubkey_prepare(Authctxt *); | |
286 | static void pubkey_cleanup(Authctxt *); | |
287 | static Key *load_identity_file(char *); | |
3c0ef626 | 288 | |
289 | static Authmethod *authmethod_get(char *authlist); | |
290 | static Authmethod *authmethod_lookup(const char *name); | |
291 | static char *authmethods_get(void); | |
292 | ||
293 | Authmethod authmethods[] = { | |
0fff78ff | 294 | #ifdef GSSAPI |
70e5f740 | 295 | {"gssapi-keyex", |
296 | userauth_gsskeyex, | |
297 | &options.gss_authentication, | |
298 | NULL}, | |
cdd66111 | 299 | {"gssapi-with-mic", |
0fff78ff | 300 | userauth_gssapi, |
301 | &options.gss_authentication, | |
302 | NULL}, | |
303 | #endif | |
3c0ef626 | 304 | {"hostbased", |
305 | userauth_hostbased, | |
306 | &options.hostbased_authentication, | |
307 | NULL}, | |
308 | {"publickey", | |
309 | userauth_pubkey, | |
310 | &options.pubkey_authentication, | |
311 | NULL}, | |
312 | {"keyboard-interactive", | |
313 | userauth_kbdint, | |
314 | &options.kbd_interactive_authentication, | |
315 | &options.batch_mode}, | |
316 | {"password", | |
317 | userauth_passwd, | |
318 | &options.password_authentication, | |
319 | &options.batch_mode}, | |
320 | {"none", | |
321 | userauth_none, | |
322 | NULL, | |
323 | NULL}, | |
324 | {NULL, NULL, NULL, NULL} | |
325 | }; | |
326 | ||
327 | void | |
328 | ssh_userauth2(const char *local_user, const char *server_user, char *host, | |
f5799ae1 | 329 | Sensitive *sensitive) |
3c0ef626 | 330 | { |
331 | Authctxt authctxt; | |
332 | int type; | |
3c0ef626 | 333 | |
334 | if (options.challenge_response_authentication) | |
335 | options.kbd_interactive_authentication = 1; | |
336 | ||
3c0ef626 | 337 | packet_start(SSH2_MSG_SERVICE_REQUEST); |
338 | packet_put_cstring("ssh-userauth"); | |
339 | packet_send(); | |
6a9b3198 | 340 | debug("SSH2_MSG_SERVICE_REQUEST sent"); |
3c0ef626 | 341 | packet_write_wait(); |
e9a17296 | 342 | type = packet_read(); |
6a9b3198 | 343 | if (type != SSH2_MSG_SERVICE_ACCEPT) |
344 | fatal("Server denied authentication request: %d", type); | |
3c0ef626 | 345 | if (packet_remaining() > 0) { |
e9a17296 | 346 | char *reply = packet_get_string(NULL); |
6a9b3198 | 347 | debug2("service_accept: %s", reply); |
3c0ef626 | 348 | xfree(reply); |
349 | } else { | |
6a9b3198 | 350 | debug2("buggy server: service_accept w/o service"); |
3c0ef626 | 351 | } |
e9a17296 | 352 | packet_check_eom(); |
6a9b3198 | 353 | debug("SSH2_MSG_SERVICE_ACCEPT received"); |
3c0ef626 | 354 | |
355 | if (options.preferred_authentications == NULL) | |
356 | options.preferred_authentications = authmethods_get(); | |
357 | ||
358 | /* setup authentication context */ | |
359 | memset(&authctxt, 0, sizeof(authctxt)); | |
0fff78ff | 360 | pubkey_prepare(&authctxt); |
3c0ef626 | 361 | authctxt.server_user = server_user; |
362 | authctxt.local_user = local_user; | |
363 | authctxt.host = host; | |
364 | authctxt.service = "ssh-connection"; /* service name */ | |
365 | authctxt.success = 0; | |
366 | authctxt.method = authmethod_lookup("none"); | |
367 | authctxt.authlist = NULL; | |
0fff78ff | 368 | authctxt.methoddata = NULL; |
f5799ae1 | 369 | authctxt.sensitive = sensitive; |
3c0ef626 | 370 | authctxt.info_req_seen = 0; |
371 | if (authctxt.method == NULL) | |
372 | fatal("ssh_userauth2: internal error: cannot send userauth none request"); | |
373 | ||
374 | /* initial userauth request */ | |
375 | userauth_none(&authctxt); | |
376 | ||
377 | dispatch_init(&input_userauth_error); | |
378 | dispatch_set(SSH2_MSG_USERAUTH_SUCCESS, &input_userauth_success); | |
379 | dispatch_set(SSH2_MSG_USERAUTH_FAILURE, &input_userauth_failure); | |
380 | dispatch_set(SSH2_MSG_USERAUTH_BANNER, &input_userauth_banner); | |
381 | dispatch_run(DISPATCH_BLOCK, &authctxt.success, &authctxt); /* loop until success */ | |
382 | ||
0fff78ff | 383 | pubkey_cleanup(&authctxt); |
384 | dispatch_range(SSH2_MSG_USERAUTH_MIN, SSH2_MSG_USERAUTH_MAX, NULL); | |
3c0ef626 | 385 | |
d6f3ca1e | 386 | /* if the user wants to use the none cipher do it */ |
387 | /* post authentication and only if the right conditions are met */ | |
388 | /* both of the NONE commands must be true and there must be no */ | |
389 | /* tty allocated */ | |
390 | if ((options.none_switch == 1) && (options.none_enabled == 1)) | |
391 | { | |
392 | if (!tty_flag) /* no null on tty sessions */ | |
393 | { | |
394 | debug("Requesting none rekeying..."); | |
395 | myproposal[PROPOSAL_ENC_ALGS_STOC] = "none"; | |
396 | myproposal[PROPOSAL_ENC_ALGS_CTOS] = "none"; | |
397 | kex_prop2buf(&xxx_kex->my,myproposal); | |
398 | packet_request_rekeying(); | |
399 | fprintf(stderr, "WARNING: ENABLED NONE CIPHER\n"); | |
400 | } | |
401 | else | |
402 | { | |
403 | /* requested NONE cipher when in a tty */ | |
404 | debug("Cannot switch to NONE cipher with tty allocated"); | |
405 | fprintf(stderr, "NONE cipher switch disabled when a TTY is allocated\n"); | |
406 | } | |
407 | } | |
6a9b3198 | 408 | debug("Authentication succeeded (%s).", authctxt.method->name); |
3c0ef626 | 409 | } |
0fff78ff | 410 | |
3c0ef626 | 411 | void |
412 | userauth(Authctxt *authctxt, char *authlist) | |
413 | { | |
0fff78ff | 414 | if (authctxt->methoddata) { |
415 | xfree(authctxt->methoddata); | |
416 | authctxt->methoddata = NULL; | |
417 | } | |
3c0ef626 | 418 | if (authlist == NULL) { |
419 | authlist = authctxt->authlist; | |
420 | } else { | |
421 | if (authctxt->authlist) | |
422 | xfree(authctxt->authlist); | |
423 | authctxt->authlist = authlist; | |
424 | } | |
425 | for (;;) { | |
426 | Authmethod *method = authmethod_get(authlist); | |
427 | if (method == NULL) | |
428 | fatal("Permission denied (%s).", authlist); | |
429 | authctxt->method = method; | |
0fff78ff | 430 | |
431 | /* reset the per method handler */ | |
432 | dispatch_range(SSH2_MSG_USERAUTH_PER_METHOD_MIN, | |
433 | SSH2_MSG_USERAUTH_PER_METHOD_MAX, NULL); | |
434 | ||
435 | /* and try new method */ | |
3c0ef626 | 436 | if (method->userauth(authctxt) != 0) { |
437 | debug2("we sent a %s packet, wait for reply", method->name); | |
438 | break; | |
439 | } else { | |
440 | debug2("we did not send a packet, disable method"); | |
441 | method->enabled = NULL; | |
442 | } | |
443 | } | |
444 | } | |
680cee3b | 445 | |
3c0ef626 | 446 | void |
e9a17296 | 447 | input_userauth_error(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 448 | { |
449 | fatal("input_userauth_error: bad message during authentication: " | |
665a873d | 450 | "type %d", type); |
3c0ef626 | 451 | } |
680cee3b | 452 | |
3c0ef626 | 453 | void |
e9a17296 | 454 | input_userauth_banner(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 455 | { |
456 | char *msg, *lang; | |
cdd66111 | 457 | |
3c0ef626 | 458 | debug3("input_userauth_banner"); |
459 | msg = packet_get_string(NULL); | |
460 | lang = packet_get_string(NULL); | |
9108f8d9 | 461 | if (options.log_level >= SYSLOG_LEVEL_INFO) |
cdd66111 | 462 | fprintf(stderr, "%s", msg); |
3c0ef626 | 463 | xfree(msg); |
464 | xfree(lang); | |
465 | } | |
680cee3b | 466 | |
3c0ef626 | 467 | void |
e9a17296 | 468 | input_userauth_success(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 469 | { |
470 | Authctxt *authctxt = ctxt; | |
471 | if (authctxt == NULL) | |
472 | fatal("input_userauth_success: no authentication context"); | |
cdd66111 | 473 | if (authctxt->authlist) { |
3c0ef626 | 474 | xfree(authctxt->authlist); |
cdd66111 | 475 | authctxt->authlist = NULL; |
476 | } | |
477 | if (authctxt->methoddata) { | |
0fff78ff | 478 | xfree(authctxt->methoddata); |
cdd66111 | 479 | authctxt->methoddata = NULL; |
480 | } | |
3c0ef626 | 481 | authctxt->success = 1; /* break out */ |
482 | } | |
680cee3b | 483 | |
3c0ef626 | 484 | void |
e9a17296 | 485 | input_userauth_failure(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 486 | { |
487 | Authctxt *authctxt = ctxt; | |
488 | char *authlist = NULL; | |
489 | int partial; | |
490 | ||
491 | if (authctxt == NULL) | |
492 | fatal("input_userauth_failure: no authentication context"); | |
493 | ||
494 | authlist = packet_get_string(NULL); | |
495 | partial = packet_get_char(); | |
e9a17296 | 496 | packet_check_eom(); |
3c0ef626 | 497 | |
498 | if (partial != 0) | |
0fff78ff | 499 | logit("Authenticated with partial success."); |
6a9b3198 | 500 | debug("Authentications that can continue: %s", authlist); |
3c0ef626 | 501 | |
3c0ef626 | 502 | userauth(authctxt, authlist); |
503 | } | |
504 | void | |
e9a17296 | 505 | input_userauth_pk_ok(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 506 | { |
507 | Authctxt *authctxt = ctxt; | |
508 | Key *key = NULL; | |
0fff78ff | 509 | Identity *id = NULL; |
3c0ef626 | 510 | Buffer b; |
e9a17296 | 511 | int pktype, sent = 0; |
512 | u_int alen, blen; | |
513 | char *pkalg, *fp; | |
514 | u_char *pkblob; | |
3c0ef626 | 515 | |
516 | if (authctxt == NULL) | |
517 | fatal("input_userauth_pk_ok: no authentication context"); | |
518 | if (datafellows & SSH_BUG_PKOK) { | |
519 | /* this is similar to SSH_BUG_PKAUTH */ | |
520 | debug2("input_userauth_pk_ok: SSH_BUG_PKOK"); | |
521 | pkblob = packet_get_string(&blen); | |
522 | buffer_init(&b); | |
523 | buffer_append(&b, pkblob, blen); | |
524 | pkalg = buffer_get_string(&b, &alen); | |
525 | buffer_free(&b); | |
526 | } else { | |
527 | pkalg = packet_get_string(&alen); | |
528 | pkblob = packet_get_string(&blen); | |
529 | } | |
e9a17296 | 530 | packet_check_eom(); |
3c0ef626 | 531 | |
0fff78ff | 532 | debug("Server accepts key: pkalg %s blen %u", pkalg, blen); |
3c0ef626 | 533 | |
0fff78ff | 534 | if ((pktype = key_type_from_name(pkalg)) == KEY_UNSPEC) { |
535 | debug("unknown pkalg %s", pkalg); | |
536 | goto done; | |
537 | } | |
538 | if ((key = key_from_blob(pkblob, blen)) == NULL) { | |
539 | debug("no key from blob. pkalg %s", pkalg); | |
540 | goto done; | |
541 | } | |
542 | if (key->type != pktype) { | |
543 | error("input_userauth_pk_ok: type mismatch " | |
544 | "for decoded key (received %d, expected %d)", | |
545 | key->type, pktype); | |
546 | goto done; | |
547 | } | |
548 | fp = key_fingerprint(key, SSH_FP_MD5, SSH_FP_HEX); | |
549 | debug2("input_userauth_pk_ok: fp %s", fp); | |
550 | xfree(fp); | |
551 | ||
cdd66111 | 552 | /* |
553 | * search keys in the reverse order, because last candidate has been | |
554 | * moved to the end of the queue. this also avoids confusion by | |
555 | * duplicate keys | |
556 | */ | |
c9f39d2c | 557 | TAILQ_FOREACH_REVERSE(id, &authctxt->keys, idlist, next) { |
0fff78ff | 558 | if (key_equal(key, id->key)) { |
559 | sent = sign_and_send_pubkey(authctxt, id); | |
3c0ef626 | 560 | break; |
561 | } | |
0fff78ff | 562 | } |
563 | done: | |
3c0ef626 | 564 | if (key != NULL) |
565 | key_free(key); | |
566 | xfree(pkalg); | |
567 | xfree(pkblob); | |
568 | ||
41b2f314 | 569 | /* try another method if we did not send a packet */ |
3c0ef626 | 570 | if (sent == 0) |
571 | userauth(authctxt, NULL); | |
0fff78ff | 572 | } |
573 | ||
574 | #ifdef GSSAPI | |
cdd66111 | 575 | int |
0fff78ff | 576 | userauth_gssapi(Authctxt *authctxt) |
577 | { | |
578 | Gssctxt *gssctxt = NULL; | |
cdd66111 | 579 | static gss_OID_set gss_supported = NULL; |
665a873d | 580 | static u_int mech = 0; |
0fff78ff | 581 | OM_uint32 min; |
582 | int ok = 0; | |
70e5f740 | 583 | char *gss_host = NULL; |
584 | ||
585 | if (options.gss_trust_dns) | |
586 | gss_host = (char *)get_canonical_hostname(1); | |
587 | else | |
588 | gss_host = (char *)authctxt->host; | |
0fff78ff | 589 | |
590 | /* Try one GSSAPI method at a time, rather than sending them all at | |
591 | * once. */ | |
592 | ||
cdd66111 | 593 | if (gss_supported == NULL) |
594 | gss_indicate_mechs(&min, &gss_supported); | |
0fff78ff | 595 | |
596 | /* Check to see if the mechanism is usable before we offer it */ | |
cdd66111 | 597 | while (mech < gss_supported->count && !ok) { |
0fff78ff | 598 | /* My DER encoding requires length<128 */ |
cdd66111 | 599 | if (gss_supported->elements[mech].length < 128 && |
9108f8d9 | 600 | ssh_gssapi_check_mechanism(&gssctxt, |
70e5f740 | 601 | &gss_supported->elements[mech], gss_host)) { |
0fff78ff | 602 | ok = 1; /* Mechanism works */ |
603 | } else { | |
604 | mech++; | |
605 | } | |
606 | } | |
607 | ||
665a873d | 608 | if (!ok) |
609 | return 0; | |
0fff78ff | 610 | |
611 | authctxt->methoddata=(void *)gssctxt; | |
612 | ||
613 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
614 | packet_put_cstring(authctxt->server_user); | |
615 | packet_put_cstring(authctxt->service); | |
616 | packet_put_cstring(authctxt->method->name); | |
617 | ||
618 | packet_put_int(1); | |
619 | ||
cdd66111 | 620 | packet_put_int((gss_supported->elements[mech].length) + 2); |
621 | packet_put_char(SSH_GSS_OIDTYPE); | |
622 | packet_put_char(gss_supported->elements[mech].length); | |
623 | packet_put_raw(gss_supported->elements[mech].elements, | |
624 | gss_supported->elements[mech].length); | |
0fff78ff | 625 | |
626 | packet_send(); | |
627 | ||
628 | dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE, &input_gssapi_response); | |
629 | dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, &input_gssapi_token); | |
630 | dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERROR, &input_gssapi_error); | |
631 | dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, &input_gssapi_errtok); | |
632 | ||
633 | mech++; /* Move along to next candidate */ | |
634 | ||
635 | return 1; | |
636 | } | |
637 | ||
cdd66111 | 638 | static OM_uint32 |
639 | process_gssapi_token(void *ctxt, gss_buffer_t recv_tok) | |
640 | { | |
641 | Authctxt *authctxt = ctxt; | |
642 | Gssctxt *gssctxt = authctxt->methoddata; | |
643 | gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER; | |
665a873d | 644 | gss_buffer_desc mic = GSS_C_EMPTY_BUFFER; |
645 | gss_buffer_desc gssbuf; | |
cdd66111 | 646 | OM_uint32 status, ms, flags; |
647 | Buffer b; | |
648 | ||
649 | status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds, | |
650 | recv_tok, &send_tok, &flags); | |
651 | ||
652 | if (send_tok.length > 0) { | |
653 | if (GSS_ERROR(status)) | |
654 | packet_start(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK); | |
655 | else | |
656 | packet_start(SSH2_MSG_USERAUTH_GSSAPI_TOKEN); | |
657 | ||
658 | packet_put_string(send_tok.value, send_tok.length); | |
659 | packet_send(); | |
660 | gss_release_buffer(&ms, &send_tok); | |
661 | } | |
662 | ||
663 | if (status == GSS_S_COMPLETE) { | |
664 | /* send either complete or MIC, depending on mechanism */ | |
665 | if (!(flags & GSS_C_INTEG_FLAG)) { | |
666 | packet_start(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE); | |
667 | packet_send(); | |
668 | } else { | |
669 | ssh_gssapi_buildmic(&b, authctxt->server_user, | |
670 | authctxt->service, "gssapi-with-mic"); | |
671 | ||
672 | gssbuf.value = buffer_ptr(&b); | |
673 | gssbuf.length = buffer_len(&b); | |
674 | ||
675 | status = ssh_gssapi_sign(gssctxt, &gssbuf, &mic); | |
676 | ||
677 | if (!GSS_ERROR(status)) { | |
678 | packet_start(SSH2_MSG_USERAUTH_GSSAPI_MIC); | |
679 | packet_put_string(mic.value, mic.length); | |
680 | ||
681 | packet_send(); | |
682 | } | |
683 | ||
684 | buffer_free(&b); | |
685 | gss_release_buffer(&ms, &mic); | |
686 | } | |
687 | } | |
688 | ||
689 | return status; | |
690 | } | |
691 | ||
0fff78ff | 692 | void |
693 | input_gssapi_response(int type, u_int32_t plen, void *ctxt) | |
694 | { | |
695 | Authctxt *authctxt = ctxt; | |
696 | Gssctxt *gssctxt; | |
70e5f740 | 697 | u_int oidlen; |
698 | u_char *oidv; | |
0fff78ff | 699 | |
700 | if (authctxt == NULL) | |
701 | fatal("input_gssapi_response: no authentication context"); | |
702 | gssctxt = authctxt->methoddata; | |
703 | ||
704 | /* Setup our OID */ | |
705 | oidv = packet_get_string(&oidlen); | |
706 | ||
cdd66111 | 707 | if (oidlen <= 2 || |
708 | oidv[0] != SSH_GSS_OIDTYPE || | |
709 | oidv[1] != oidlen - 2) { | |
710 | xfree(oidv); | |
711 | debug("Badly encoded mechanism OID received"); | |
712 | userauth(authctxt, NULL); | |
713 | return; | |
0fff78ff | 714 | } |
715 | ||
cdd66111 | 716 | if (!ssh_gssapi_check_oid(gssctxt, oidv + 2, oidlen - 2)) |
717 | fatal("Server returned different OID than expected"); | |
718 | ||
0fff78ff | 719 | packet_check_eom(); |
720 | ||
721 | xfree(oidv); | |
722 | ||
cdd66111 | 723 | if (GSS_ERROR(process_gssapi_token(ctxt, GSS_C_NO_BUFFER))) { |
0fff78ff | 724 | /* Start again with next method on list */ |
725 | debug("Trying to start again"); | |
726 | userauth(authctxt, NULL); | |
727 | return; | |
728 | } | |
0fff78ff | 729 | } |
730 | ||
731 | void | |
732 | input_gssapi_token(int type, u_int32_t plen, void *ctxt) | |
733 | { | |
734 | Authctxt *authctxt = ctxt; | |
0fff78ff | 735 | gss_buffer_desc recv_tok; |
cdd66111 | 736 | OM_uint32 status; |
0fff78ff | 737 | u_int slen; |
738 | ||
739 | if (authctxt == NULL) | |
740 | fatal("input_gssapi_response: no authentication context"); | |
0fff78ff | 741 | |
742 | recv_tok.value = packet_get_string(&slen); | |
743 | recv_tok.length = slen; /* safe typecast */ | |
744 | ||
745 | packet_check_eom(); | |
746 | ||
cdd66111 | 747 | status = process_gssapi_token(ctxt, &recv_tok); |
0fff78ff | 748 | |
749 | xfree(recv_tok.value); | |
750 | ||
751 | if (GSS_ERROR(status)) { | |
0fff78ff | 752 | /* Start again with the next method in the list */ |
753 | userauth(authctxt, NULL); | |
754 | return; | |
755 | } | |
3c0ef626 | 756 | } |
757 | ||
0fff78ff | 758 | void |
759 | input_gssapi_errtok(int type, u_int32_t plen, void *ctxt) | |
760 | { | |
761 | Authctxt *authctxt = ctxt; | |
762 | Gssctxt *gssctxt; | |
763 | gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER; | |
764 | gss_buffer_desc recv_tok; | |
765 | OM_uint32 status, ms; | |
766 | u_int len; | |
767 | ||
768 | if (authctxt == NULL) | |
769 | fatal("input_gssapi_response: no authentication context"); | |
770 | gssctxt = authctxt->methoddata; | |
771 | ||
772 | recv_tok.value = packet_get_string(&len); | |
773 | recv_tok.length = len; | |
774 | ||
775 | packet_check_eom(); | |
776 | ||
777 | /* Stick it into GSSAPI and see what it says */ | |
778 | status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds, | |
665a873d | 779 | &recv_tok, &send_tok, NULL); |
0fff78ff | 780 | |
781 | xfree(recv_tok.value); | |
782 | gss_release_buffer(&ms, &send_tok); | |
783 | ||
784 | /* Server will be returning a failed packet after this one */ | |
785 | } | |
786 | ||
787 | void | |
788 | input_gssapi_error(int type, u_int32_t plen, void *ctxt) | |
789 | { | |
790 | OM_uint32 maj, min; | |
791 | char *msg; | |
792 | char *lang; | |
793 | ||
794 | maj=packet_get_int(); | |
795 | min=packet_get_int(); | |
796 | msg=packet_get_string(NULL); | |
797 | lang=packet_get_string(NULL); | |
798 | ||
799 | packet_check_eom(); | |
800 | ||
2c06c99b | 801 | debug("Server GSSAPI Error:\n%s", msg); |
0fff78ff | 802 | xfree(msg); |
803 | xfree(lang); | |
804 | } | |
70e5f740 | 805 | |
806 | int | |
807 | userauth_gsskeyex(Authctxt *authctxt) | |
808 | { | |
809 | Buffer b; | |
810 | gss_buffer_desc gssbuf; | |
811 | gss_buffer_desc mic = GSS_C_EMPTY_BUFFER; | |
812 | OM_uint32 ms; | |
813 | ||
814 | static int attempt = 0; | |
815 | if (attempt++ >= 1) | |
816 | return (0); | |
817 | ||
818 | if (gss_kex_context == NULL) { | |
819 | debug("No valid Key exchange context"); | |
820 | return (0); | |
821 | } | |
822 | ||
823 | ssh_gssapi_buildmic(&b, authctxt->server_user, authctxt->service, | |
824 | "gssapi-keyex"); | |
825 | ||
826 | gssbuf.value = buffer_ptr(&b); | |
827 | gssbuf.length = buffer_len(&b); | |
828 | ||
829 | if (GSS_ERROR(ssh_gssapi_sign(gss_kex_context, &gssbuf, &mic))) { | |
830 | buffer_free(&b); | |
831 | return (0); | |
832 | } | |
833 | ||
834 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
835 | packet_put_cstring(authctxt->server_user); | |
836 | packet_put_cstring(authctxt->service); | |
837 | packet_put_cstring(authctxt->method->name); | |
838 | packet_put_string(mic.value, mic.length); | |
839 | packet_send(); | |
840 | ||
841 | buffer_free(&b); | |
842 | gss_release_buffer(&ms, &mic); | |
843 | ||
844 | return (1); | |
845 | } | |
846 | ||
0fff78ff | 847 | #endif /* GSSAPI */ |
848 | ||
3c0ef626 | 849 | int |
850 | userauth_none(Authctxt *authctxt) | |
851 | { | |
852 | /* initial userauth request */ | |
853 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
854 | packet_put_cstring(authctxt->server_user); | |
855 | packet_put_cstring(authctxt->service); | |
856 | packet_put_cstring(authctxt->method->name); | |
857 | packet_send(); | |
858 | return 1; | |
859 | } | |
860 | ||
861 | int | |
862 | userauth_passwd(Authctxt *authctxt) | |
863 | { | |
864 | static int attempt = 0; | |
700318f3 | 865 | char prompt[150]; |
3c0ef626 | 866 | char *password; |
867 | ||
868 | if (attempt++ >= options.number_of_password_prompts) | |
869 | return 0; | |
870 | ||
e9a17296 | 871 | if (attempt != 1) |
3c0ef626 | 872 | error("Permission denied, please try again."); |
873 | ||
874 | snprintf(prompt, sizeof(prompt), "%.30s@%.128s's password: ", | |
875 | authctxt->server_user, authctxt->host); | |
876 | password = read_passphrase(prompt, 0); | |
877 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
878 | packet_put_cstring(authctxt->server_user); | |
879 | packet_put_cstring(authctxt->service); | |
880 | packet_put_cstring(authctxt->method->name); | |
881 | packet_put_char(0); | |
882 | packet_put_cstring(password); | |
883 | memset(password, 0, strlen(password)); | |
884 | xfree(password); | |
885 | packet_add_padding(64); | |
886 | packet_send(); | |
700318f3 | 887 | |
f5799ae1 | 888 | dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, |
700318f3 | 889 | &input_userauth_passwd_changereq); |
890 | ||
3c0ef626 | 891 | return 1; |
892 | } | |
700318f3 | 893 | /* |
894 | * parse PASSWD_CHANGEREQ, prompt user and send SSH2_MSG_USERAUTH_REQUEST | |
895 | */ | |
896 | void | |
897 | input_userauth_passwd_changereq(int type, u_int32_t seqnr, void *ctxt) | |
898 | { | |
899 | Authctxt *authctxt = ctxt; | |
900 | char *info, *lang, *password = NULL, *retype = NULL; | |
901 | char prompt[150]; | |
902 | ||
903 | debug2("input_userauth_passwd_changereq"); | |
904 | ||
905 | if (authctxt == NULL) | |
906 | fatal("input_userauth_passwd_changereq: " | |
907 | "no authentication context"); | |
908 | ||
909 | info = packet_get_string(NULL); | |
910 | lang = packet_get_string(NULL); | |
911 | if (strlen(info) > 0) | |
0fff78ff | 912 | logit("%s", info); |
700318f3 | 913 | xfree(info); |
914 | xfree(lang); | |
915 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
916 | packet_put_cstring(authctxt->server_user); | |
917 | packet_put_cstring(authctxt->service); | |
918 | packet_put_cstring(authctxt->method->name); | |
919 | packet_put_char(1); /* additional info */ | |
f5799ae1 | 920 | snprintf(prompt, sizeof(prompt), |
700318f3 | 921 | "Enter %.30s@%.128s's old password: ", |
922 | authctxt->server_user, authctxt->host); | |
923 | password = read_passphrase(prompt, 0); | |
924 | packet_put_cstring(password); | |
925 | memset(password, 0, strlen(password)); | |
926 | xfree(password); | |
927 | password = NULL; | |
928 | while (password == NULL) { | |
f5799ae1 | 929 | snprintf(prompt, sizeof(prompt), |
700318f3 | 930 | "Enter %.30s@%.128s's new password: ", |
931 | authctxt->server_user, authctxt->host); | |
932 | password = read_passphrase(prompt, RP_ALLOW_EOF); | |
933 | if (password == NULL) { | |
934 | /* bail out */ | |
935 | return; | |
936 | } | |
f5799ae1 | 937 | snprintf(prompt, sizeof(prompt), |
700318f3 | 938 | "Retype %.30s@%.128s's new password: ", |
939 | authctxt->server_user, authctxt->host); | |
940 | retype = read_passphrase(prompt, 0); | |
941 | if (strcmp(password, retype) != 0) { | |
942 | memset(password, 0, strlen(password)); | |
943 | xfree(password); | |
0fff78ff | 944 | logit("Mismatch; try again, EOF to quit."); |
700318f3 | 945 | password = NULL; |
946 | } | |
947 | memset(retype, 0, strlen(retype)); | |
948 | xfree(retype); | |
949 | } | |
950 | packet_put_cstring(password); | |
951 | memset(password, 0, strlen(password)); | |
952 | xfree(password); | |
953 | packet_add_padding(64); | |
954 | packet_send(); | |
f5799ae1 | 955 | |
956 | dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, | |
700318f3 | 957 | &input_userauth_passwd_changereq); |
958 | } | |
3c0ef626 | 959 | |
0fff78ff | 960 | static int |
961 | identity_sign(Identity *id, u_char **sigp, u_int *lenp, | |
962 | u_char *data, u_int datalen) | |
3c0ef626 | 963 | { |
0fff78ff | 964 | Key *prv; |
965 | int ret; | |
700318f3 | 966 | |
0fff78ff | 967 | /* the agent supports this key */ |
968 | if (id->ac) | |
969 | return (ssh_agent_sign(id->ac, id->key, sigp, lenp, | |
970 | data, datalen)); | |
971 | /* | |
972 | * we have already loaded the private key or | |
973 | * the private key is stored in external hardware | |
974 | */ | |
975 | if (id->isprivate || (id->key->flags & KEY_FLAG_EXT)) | |
976 | return (key_sign(id->key, sigp, lenp, data, datalen)); | |
977 | /* load the private key from the file */ | |
978 | if ((prv = load_identity_file(id->filename)) == NULL) | |
979 | return (-1); | |
980 | ret = key_sign(prv, sigp, lenp, data, datalen); | |
981 | key_free(prv); | |
982 | return (ret); | |
3c0ef626 | 983 | } |
984 | ||
985 | static int | |
0fff78ff | 986 | sign_and_send_pubkey(Authctxt *authctxt, Identity *id) |
3c0ef626 | 987 | { |
988 | Buffer b; | |
989 | u_char *blob, *signature; | |
e9a17296 | 990 | u_int bloblen, slen; |
0fff78ff | 991 | u_int skip = 0; |
3c0ef626 | 992 | int ret = -1; |
993 | int have_sig = 1; | |
994 | ||
995 | debug3("sign_and_send_pubkey"); | |
996 | ||
0fff78ff | 997 | if (key_to_blob(id->key, &blob, &bloblen) == 0) { |
3c0ef626 | 998 | /* we cannot handle this key */ |
999 | debug3("sign_and_send_pubkey: cannot handle key"); | |
1000 | return 0; | |
1001 | } | |
1002 | /* data to be signed */ | |
1003 | buffer_init(&b); | |
1004 | if (datafellows & SSH_OLD_SESSIONID) { | |
1005 | buffer_append(&b, session_id2, session_id2_len); | |
1006 | skip = session_id2_len; | |
1007 | } else { | |
1008 | buffer_put_string(&b, session_id2, session_id2_len); | |
1009 | skip = buffer_len(&b); | |
1010 | } | |
1011 | buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST); | |
1012 | buffer_put_cstring(&b, authctxt->server_user); | |
1013 | buffer_put_cstring(&b, | |
1014 | datafellows & SSH_BUG_PKSERVICE ? | |
1015 | "ssh-userauth" : | |
1016 | authctxt->service); | |
1017 | if (datafellows & SSH_BUG_PKAUTH) { | |
1018 | buffer_put_char(&b, have_sig); | |
1019 | } else { | |
1020 | buffer_put_cstring(&b, authctxt->method->name); | |
1021 | buffer_put_char(&b, have_sig); | |
0fff78ff | 1022 | buffer_put_cstring(&b, key_ssh_name(id->key)); |
3c0ef626 | 1023 | } |
1024 | buffer_put_string(&b, blob, bloblen); | |
1025 | ||
1026 | /* generate signature */ | |
0fff78ff | 1027 | ret = identity_sign(id, &signature, &slen, |
3c0ef626 | 1028 | buffer_ptr(&b), buffer_len(&b)); |
1029 | if (ret == -1) { | |
1030 | xfree(blob); | |
1031 | buffer_free(&b); | |
1032 | return 0; | |
1033 | } | |
1034 | #ifdef DEBUG_PK | |
1035 | buffer_dump(&b); | |
1036 | #endif | |
1037 | if (datafellows & SSH_BUG_PKSERVICE) { | |
1038 | buffer_clear(&b); | |
1039 | buffer_append(&b, session_id2, session_id2_len); | |
1040 | skip = session_id2_len; | |
1041 | buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST); | |
1042 | buffer_put_cstring(&b, authctxt->server_user); | |
1043 | buffer_put_cstring(&b, authctxt->service); | |
1044 | buffer_put_cstring(&b, authctxt->method->name); | |
1045 | buffer_put_char(&b, have_sig); | |
1046 | if (!(datafellows & SSH_BUG_PKAUTH)) | |
0fff78ff | 1047 | buffer_put_cstring(&b, key_ssh_name(id->key)); |
3c0ef626 | 1048 | buffer_put_string(&b, blob, bloblen); |
1049 | } | |
1050 | xfree(blob); | |
1051 | ||
1052 | /* append signature */ | |
1053 | buffer_put_string(&b, signature, slen); | |
1054 | xfree(signature); | |
1055 | ||
1056 | /* skip session id and packet type */ | |
1057 | if (buffer_len(&b) < skip + 1) | |
1058 | fatal("userauth_pubkey: internal error"); | |
1059 | buffer_consume(&b, skip + 1); | |
1060 | ||
1061 | /* put remaining data from buffer into packet */ | |
1062 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
1063 | packet_put_raw(buffer_ptr(&b), buffer_len(&b)); | |
1064 | buffer_free(&b); | |
1065 | packet_send(); | |
1066 | ||
1067 | return 1; | |
1068 | } | |
1069 | ||
1070 | static int | |
0fff78ff | 1071 | send_pubkey_test(Authctxt *authctxt, Identity *id) |
3c0ef626 | 1072 | { |
1073 | u_char *blob; | |
e9a17296 | 1074 | u_int bloblen, have_sig = 0; |
3c0ef626 | 1075 | |
1076 | debug3("send_pubkey_test"); | |
1077 | ||
0fff78ff | 1078 | if (key_to_blob(id->key, &blob, &bloblen) == 0) { |
3c0ef626 | 1079 | /* we cannot handle this key */ |
1080 | debug3("send_pubkey_test: cannot handle key"); | |
1081 | return 0; | |
1082 | } | |
1083 | /* register callback for USERAUTH_PK_OK message */ | |
3c0ef626 | 1084 | dispatch_set(SSH2_MSG_USERAUTH_PK_OK, &input_userauth_pk_ok); |
1085 | ||
1086 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
1087 | packet_put_cstring(authctxt->server_user); | |
1088 | packet_put_cstring(authctxt->service); | |
1089 | packet_put_cstring(authctxt->method->name); | |
1090 | packet_put_char(have_sig); | |
1091 | if (!(datafellows & SSH_BUG_PKAUTH)) | |
0fff78ff | 1092 | packet_put_cstring(key_ssh_name(id->key)); |
3c0ef626 | 1093 | packet_put_string(blob, bloblen); |
1094 | xfree(blob); | |
1095 | packet_send(); | |
1096 | return 1; | |
1097 | } | |
1098 | ||
1099 | static Key * | |
1100 | load_identity_file(char *filename) | |
1101 | { | |
1102 | Key *private; | |
1103 | char prompt[300], *passphrase; | |
9108f8d9 | 1104 | int perm_ok, quit, i; |
3c0ef626 | 1105 | struct stat st; |
1106 | ||
1107 | if (stat(filename, &st) < 0) { | |
1108 | debug3("no such identity: %s", filename); | |
1109 | return NULL; | |
1110 | } | |
9108f8d9 | 1111 | private = key_load_private_type(KEY_UNSPEC, filename, "", NULL, &perm_ok); |
1112 | if (!perm_ok) | |
1113 | return NULL; | |
3c0ef626 | 1114 | if (private == NULL) { |
1115 | if (options.batch_mode) | |
1116 | return NULL; | |
1117 | snprintf(prompt, sizeof prompt, | |
e9a17296 | 1118 | "Enter passphrase for key '%.100s': ", filename); |
3c0ef626 | 1119 | for (i = 0; i < options.number_of_password_prompts; i++) { |
1120 | passphrase = read_passphrase(prompt, 0); | |
1121 | if (strcmp(passphrase, "") != 0) { | |
9108f8d9 | 1122 | private = key_load_private_type(KEY_UNSPEC, |
1123 | filename, passphrase, NULL, NULL); | |
3c0ef626 | 1124 | quit = 0; |
1125 | } else { | |
1126 | debug2("no passphrase given, try next key"); | |
1127 | quit = 1; | |
1128 | } | |
1129 | memset(passphrase, 0, strlen(passphrase)); | |
1130 | xfree(passphrase); | |
1131 | if (private != NULL || quit) | |
1132 | break; | |
1133 | debug2("bad passphrase given, try again..."); | |
1134 | } | |
1135 | } | |
1136 | return private; | |
1137 | } | |
1138 | ||
0fff78ff | 1139 | /* |
1140 | * try keys in the following order: | |
1141 | * 1. agent keys that are found in the config file | |
1142 | * 2. other agent keys | |
1143 | * 3. keys that are only listed in the config file | |
1144 | */ | |
1145 | static void | |
1146 | pubkey_prepare(Authctxt *authctxt) | |
3c0ef626 | 1147 | { |
0fff78ff | 1148 | Identity *id; |
1149 | Idlist agent, files, *preferred; | |
1150 | Key *key; | |
1151 | AuthenticationConnection *ac; | |
1152 | char *comment; | |
1153 | int i, found; | |
1154 | ||
1155 | TAILQ_INIT(&agent); /* keys from the agent */ | |
1156 | TAILQ_INIT(&files); /* keys from the config file */ | |
1157 | preferred = &authctxt->keys; | |
1158 | TAILQ_INIT(preferred); /* preferred order of keys */ | |
1159 | ||
1160 | /* list of keys stored in the filesystem */ | |
1161 | for (i = 0; i < options.num_identity_files; i++) { | |
1162 | key = options.identity_keys[i]; | |
1163 | if (key && key->type == KEY_RSA1) | |
1164 | continue; | |
1165 | options.identity_keys[i] = NULL; | |
9108f8d9 | 1166 | id = xcalloc(1, sizeof(*id)); |
0fff78ff | 1167 | id->key = key; |
1168 | id->filename = xstrdup(options.identity_files[i]); | |
1169 | TAILQ_INSERT_TAIL(&files, id, next); | |
1170 | } | |
1171 | /* list of keys supported by the agent */ | |
1172 | if ((ac = ssh_get_authentication_connection())) { | |
1173 | for (key = ssh_get_first_identity(ac, &comment, 2); | |
1174 | key != NULL; | |
1175 | key = ssh_get_next_identity(ac, &comment, 2)) { | |
1176 | found = 0; | |
1177 | TAILQ_FOREACH(id, &files, next) { | |
cdd66111 | 1178 | /* agent keys from the config file are preferred */ |
0fff78ff | 1179 | if (key_equal(key, id->key)) { |
1180 | key_free(key); | |
1181 | xfree(comment); | |
1182 | TAILQ_REMOVE(&files, id, next); | |
1183 | TAILQ_INSERT_TAIL(preferred, id, next); | |
1184 | id->ac = ac; | |
1185 | found = 1; | |
1186 | break; | |
1187 | } | |
1188 | } | |
99be0775 | 1189 | if (!found && !options.identities_only) { |
9108f8d9 | 1190 | id = xcalloc(1, sizeof(*id)); |
0fff78ff | 1191 | id->key = key; |
1192 | id->filename = comment; | |
1193 | id->ac = ac; | |
1194 | TAILQ_INSERT_TAIL(&agent, id, next); | |
1195 | } | |
1196 | } | |
1197 | /* append remaining agent keys */ | |
1198 | for (id = TAILQ_FIRST(&agent); id; id = TAILQ_FIRST(&agent)) { | |
1199 | TAILQ_REMOVE(&agent, id, next); | |
1200 | TAILQ_INSERT_TAIL(preferred, id, next); | |
1201 | } | |
1202 | authctxt->agent = ac; | |
1203 | } | |
1204 | /* append remaining keys from the config file */ | |
1205 | for (id = TAILQ_FIRST(&files); id; id = TAILQ_FIRST(&files)) { | |
1206 | TAILQ_REMOVE(&files, id, next); | |
1207 | TAILQ_INSERT_TAIL(preferred, id, next); | |
1208 | } | |
1209 | TAILQ_FOREACH(id, preferred, next) { | |
1210 | debug2("key: %s (%p)", id->filename, id->key); | |
1211 | } | |
3c0ef626 | 1212 | } |
1213 | ||
0fff78ff | 1214 | static void |
1215 | pubkey_cleanup(Authctxt *authctxt) | |
3c0ef626 | 1216 | { |
0fff78ff | 1217 | Identity *id; |
1218 | ||
1219 | if (authctxt->agent != NULL) | |
1220 | ssh_close_authentication_connection(authctxt->agent); | |
1221 | for (id = TAILQ_FIRST(&authctxt->keys); id; | |
1222 | id = TAILQ_FIRST(&authctxt->keys)) { | |
1223 | TAILQ_REMOVE(&authctxt->keys, id, next); | |
1224 | if (id->key) | |
1225 | key_free(id->key); | |
1226 | if (id->filename) | |
1227 | xfree(id->filename); | |
1228 | xfree(id); | |
3c0ef626 | 1229 | } |
3c0ef626 | 1230 | } |
1231 | ||
1232 | int | |
1233 | userauth_pubkey(Authctxt *authctxt) | |
1234 | { | |
0fff78ff | 1235 | Identity *id; |
3c0ef626 | 1236 | int sent = 0; |
0fff78ff | 1237 | |
1238 | while ((id = TAILQ_FIRST(&authctxt->keys))) { | |
1239 | if (id->tried++) | |
1240 | return (0); | |
cdd66111 | 1241 | /* move key to the end of the queue */ |
0fff78ff | 1242 | TAILQ_REMOVE(&authctxt->keys, id, next); |
1243 | TAILQ_INSERT_TAIL(&authctxt->keys, id, next); | |
1244 | /* | |
1245 | * send a test message if we have the public key. for | |
1246 | * encrypted keys we cannot do this and have to load the | |
1247 | * private key instead | |
1248 | */ | |
1249 | if (id->key && id->key->type != KEY_RSA1) { | |
1250 | debug("Offering public key: %s", id->filename); | |
1251 | sent = send_pubkey_test(authctxt, id); | |
1252 | } else if (id->key == NULL) { | |
1253 | debug("Trying private key: %s", id->filename); | |
1254 | id->key = load_identity_file(id->filename); | |
1255 | if (id->key != NULL) { | |
1256 | id->isprivate = 1; | |
1257 | sent = sign_and_send_pubkey(authctxt, id); | |
1258 | key_free(id->key); | |
1259 | id->key = NULL; | |
3c0ef626 | 1260 | } |
3c0ef626 | 1261 | } |
0fff78ff | 1262 | if (sent) |
1263 | return (sent); | |
3c0ef626 | 1264 | } |
0fff78ff | 1265 | return (0); |
3c0ef626 | 1266 | } |
1267 | ||
1268 | /* | |
1269 | * Send userauth request message specifying keyboard-interactive method. | |
1270 | */ | |
1271 | int | |
1272 | userauth_kbdint(Authctxt *authctxt) | |
1273 | { | |
1274 | static int attempt = 0; | |
1275 | ||
1276 | if (attempt++ >= options.number_of_password_prompts) | |
1277 | return 0; | |
1278 | /* disable if no SSH2_MSG_USERAUTH_INFO_REQUEST has been seen */ | |
1279 | if (attempt > 1 && !authctxt->info_req_seen) { | |
1280 | debug3("userauth_kbdint: disable: no info_req_seen"); | |
1281 | dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, NULL); | |
1282 | return 0; | |
1283 | } | |
1284 | ||
1285 | debug2("userauth_kbdint"); | |
1286 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
1287 | packet_put_cstring(authctxt->server_user); | |
1288 | packet_put_cstring(authctxt->service); | |
1289 | packet_put_cstring(authctxt->method->name); | |
1290 | packet_put_cstring(""); /* lang */ | |
1291 | packet_put_cstring(options.kbd_interactive_devices ? | |
1292 | options.kbd_interactive_devices : ""); | |
1293 | packet_send(); | |
1294 | ||
1295 | dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, &input_userauth_info_req); | |
1296 | return 1; | |
1297 | } | |
1298 | ||
1299 | /* | |
1300 | * parse INFO_REQUEST, prompt user and send INFO_RESPONSE | |
1301 | */ | |
1302 | void | |
e9a17296 | 1303 | input_userauth_info_req(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 1304 | { |
1305 | Authctxt *authctxt = ctxt; | |
1306 | char *name, *inst, *lang, *prompt, *response; | |
1307 | u_int num_prompts, i; | |
1308 | int echo = 0; | |
1309 | ||
1310 | debug2("input_userauth_info_req"); | |
1311 | ||
1312 | if (authctxt == NULL) | |
1313 | fatal("input_userauth_info_req: no authentication context"); | |
1314 | ||
1315 | authctxt->info_req_seen = 1; | |
1316 | ||
1317 | name = packet_get_string(NULL); | |
1318 | inst = packet_get_string(NULL); | |
1319 | lang = packet_get_string(NULL); | |
1320 | if (strlen(name) > 0) | |
0fff78ff | 1321 | logit("%s", name); |
3c0ef626 | 1322 | if (strlen(inst) > 0) |
0fff78ff | 1323 | logit("%s", inst); |
3c0ef626 | 1324 | xfree(name); |
1325 | xfree(inst); | |
1326 | xfree(lang); | |
1327 | ||
1328 | num_prompts = packet_get_int(); | |
1329 | /* | |
1330 | * Begin to build info response packet based on prompts requested. | |
1331 | * We commit to providing the correct number of responses, so if | |
1332 | * further on we run into a problem that prevents this, we have to | |
1333 | * be sure and clean this up and send a correct error response. | |
1334 | */ | |
1335 | packet_start(SSH2_MSG_USERAUTH_INFO_RESPONSE); | |
1336 | packet_put_int(num_prompts); | |
1337 | ||
1338 | debug2("input_userauth_info_req: num_prompts %d", num_prompts); | |
1339 | for (i = 0; i < num_prompts; i++) { | |
1340 | prompt = packet_get_string(NULL); | |
1341 | echo = packet_get_char(); | |
1342 | ||
1343 | response = read_passphrase(prompt, echo ? RP_ECHO : 0); | |
1344 | ||
1345 | packet_put_cstring(response); | |
1346 | memset(response, 0, strlen(response)); | |
1347 | xfree(response); | |
1348 | xfree(prompt); | |
1349 | } | |
e9a17296 | 1350 | packet_check_eom(); /* done with parsing incoming message. */ |
3c0ef626 | 1351 | |
1352 | packet_add_padding(64); | |
1353 | packet_send(); | |
1354 | } | |
1355 | ||
f5799ae1 | 1356 | static int |
680cee3b | 1357 | ssh_keysign(Key *key, u_char **sigp, u_int *lenp, |
f5799ae1 | 1358 | u_char *data, u_int datalen) |
1359 | { | |
1360 | Buffer b; | |
1361 | struct stat st; | |
1362 | pid_t pid; | |
1363 | int to[2], from[2], status, version = 2; | |
1364 | ||
6a9b3198 | 1365 | debug2("ssh_keysign called"); |
f5799ae1 | 1366 | |
1367 | if (stat(_PATH_SSH_KEY_SIGN, &st) < 0) { | |
1368 | error("ssh_keysign: no installed: %s", strerror(errno)); | |
1369 | return -1; | |
1370 | } | |
1371 | if (fflush(stdout) != 0) | |
1372 | error("ssh_keysign: fflush: %s", strerror(errno)); | |
1373 | if (pipe(to) < 0) { | |
1374 | error("ssh_keysign: pipe: %s", strerror(errno)); | |
1375 | return -1; | |
1376 | } | |
1377 | if (pipe(from) < 0) { | |
1378 | error("ssh_keysign: pipe: %s", strerror(errno)); | |
1379 | return -1; | |
1380 | } | |
1381 | if ((pid = fork()) < 0) { | |
1382 | error("ssh_keysign: fork: %s", strerror(errno)); | |
1383 | return -1; | |
1384 | } | |
1385 | if (pid == 0) { | |
9108f8d9 | 1386 | permanently_drop_suid(getuid()); |
f5799ae1 | 1387 | close(from[0]); |
1388 | if (dup2(from[1], STDOUT_FILENO) < 0) | |
1389 | fatal("ssh_keysign: dup2: %s", strerror(errno)); | |
1390 | close(to[1]); | |
1391 | if (dup2(to[0], STDIN_FILENO) < 0) | |
1392 | fatal("ssh_keysign: dup2: %s", strerror(errno)); | |
1393 | close(from[1]); | |
1394 | close(to[0]); | |
1395 | execl(_PATH_SSH_KEY_SIGN, _PATH_SSH_KEY_SIGN, (char *) 0); | |
1396 | fatal("ssh_keysign: exec(%s): %s", _PATH_SSH_KEY_SIGN, | |
1397 | strerror(errno)); | |
1398 | } | |
1399 | close(from[1]); | |
1400 | close(to[0]); | |
1401 | ||
1402 | buffer_init(&b); | |
1403 | buffer_put_int(&b, packet_get_connection_in()); /* send # of socket */ | |
1404 | buffer_put_string(&b, data, datalen); | |
cdd66111 | 1405 | if (ssh_msg_send(to[1], version, &b) == -1) |
1406 | fatal("ssh_keysign: couldn't send request"); | |
f5799ae1 | 1407 | |
41b2f314 | 1408 | if (ssh_msg_recv(from[0], &b) < 0) { |
f5799ae1 | 1409 | error("ssh_keysign: no reply"); |
cdd66111 | 1410 | buffer_free(&b); |
f5799ae1 | 1411 | return -1; |
1412 | } | |
1413 | close(from[0]); | |
1414 | close(to[1]); | |
1415 | ||
1416 | while (waitpid(pid, &status, 0) < 0) | |
1417 | if (errno != EINTR) | |
1418 | break; | |
1419 | ||
1420 | if (buffer_get_char(&b) != version) { | |
1421 | error("ssh_keysign: bad version"); | |
cdd66111 | 1422 | buffer_free(&b); |
f5799ae1 | 1423 | return -1; |
1424 | } | |
1425 | *sigp = buffer_get_string(&b, lenp); | |
cdd66111 | 1426 | buffer_free(&b); |
f5799ae1 | 1427 | |
1428 | return 0; | |
1429 | } | |
1430 | ||
3c0ef626 | 1431 | int |
1432 | userauth_hostbased(Authctxt *authctxt) | |
1433 | { | |
1434 | Key *private = NULL; | |
f5799ae1 | 1435 | Sensitive *sensitive = authctxt->sensitive; |
3c0ef626 | 1436 | Buffer b; |
1437 | u_char *signature, *blob; | |
1438 | char *chost, *pkalg, *p; | |
1439 | const char *service; | |
1440 | u_int blen, slen; | |
1441 | int ok, i, len, found = 0; | |
1442 | ||
1443 | /* check for a useful key */ | |
f5799ae1 | 1444 | for (i = 0; i < sensitive->nkeys; i++) { |
1445 | private = sensitive->keys[i]; | |
3c0ef626 | 1446 | if (private && private->type != KEY_RSA1) { |
1447 | found = 1; | |
1448 | /* we take and free the key */ | |
f5799ae1 | 1449 | sensitive->keys[i] = NULL; |
3c0ef626 | 1450 | break; |
1451 | } | |
1452 | } | |
1453 | if (!found) { | |
6a9b3198 | 1454 | debug("No more client hostkeys for hostbased authentication."); |
3c0ef626 | 1455 | return 0; |
1456 | } | |
1457 | if (key_to_blob(private, &blob, &blen) == 0) { | |
1458 | key_free(private); | |
1459 | return 0; | |
1460 | } | |
1461 | /* figure out a name for the client host */ | |
1462 | p = get_local_name(packet_get_connection_in()); | |
1463 | if (p == NULL) { | |
1464 | error("userauth_hostbased: cannot get local ipaddr/name"); | |
1465 | key_free(private); | |
9108f8d9 | 1466 | xfree(blob); |
3c0ef626 | 1467 | return 0; |
1468 | } | |
1469 | len = strlen(p) + 2; | |
9108f8d9 | 1470 | xasprintf(&chost, "%s.", p); |
3c0ef626 | 1471 | debug2("userauth_hostbased: chost %s", chost); |
6a9b3198 | 1472 | xfree(p); |
3c0ef626 | 1473 | |
1474 | service = datafellows & SSH_BUG_HBSERVICE ? "ssh-userauth" : | |
1475 | authctxt->service; | |
1476 | pkalg = xstrdup(key_ssh_name(private)); | |
1477 | buffer_init(&b); | |
1478 | /* construct data */ | |
1479 | buffer_put_string(&b, session_id2, session_id2_len); | |
1480 | buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST); | |
1481 | buffer_put_cstring(&b, authctxt->server_user); | |
1482 | buffer_put_cstring(&b, service); | |
1483 | buffer_put_cstring(&b, authctxt->method->name); | |
1484 | buffer_put_cstring(&b, pkalg); | |
1485 | buffer_put_string(&b, blob, blen); | |
1486 | buffer_put_cstring(&b, chost); | |
1487 | buffer_put_cstring(&b, authctxt->local_user); | |
1488 | #ifdef DEBUG_PK | |
1489 | buffer_dump(&b); | |
1490 | #endif | |
f5799ae1 | 1491 | if (sensitive->external_keysign) |
1492 | ok = ssh_keysign(private, &signature, &slen, | |
1493 | buffer_ptr(&b), buffer_len(&b)); | |
1494 | else | |
1495 | ok = key_sign(private, &signature, &slen, | |
1496 | buffer_ptr(&b), buffer_len(&b)); | |
3c0ef626 | 1497 | key_free(private); |
1498 | buffer_free(&b); | |
1499 | if (ok != 0) { | |
1500 | error("key_sign failed"); | |
1501 | xfree(chost); | |
1502 | xfree(pkalg); | |
9108f8d9 | 1503 | xfree(blob); |
3c0ef626 | 1504 | return 0; |
1505 | } | |
1506 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
1507 | packet_put_cstring(authctxt->server_user); | |
1508 | packet_put_cstring(authctxt->service); | |
1509 | packet_put_cstring(authctxt->method->name); | |
1510 | packet_put_cstring(pkalg); | |
1511 | packet_put_string(blob, blen); | |
1512 | packet_put_cstring(chost); | |
1513 | packet_put_cstring(authctxt->local_user); | |
1514 | packet_put_string(signature, slen); | |
1515 | memset(signature, 's', slen); | |
1516 | xfree(signature); | |
1517 | xfree(chost); | |
1518 | xfree(pkalg); | |
9108f8d9 | 1519 | xfree(blob); |
3c0ef626 | 1520 | |
1521 | packet_send(); | |
1522 | return 1; | |
1523 | } | |
1524 | ||
1525 | /* find auth method */ | |
1526 | ||
1527 | /* | |
1528 | * given auth method name, if configurable options permit this method fill | |
1529 | * in auth_ident field and return true, otherwise return false. | |
1530 | */ | |
1531 | static int | |
1532 | authmethod_is_enabled(Authmethod *method) | |
1533 | { | |
1534 | if (method == NULL) | |
1535 | return 0; | |
1536 | /* return false if options indicate this method is disabled */ | |
1537 | if (method->enabled == NULL || *method->enabled == 0) | |
1538 | return 0; | |
1539 | /* return false if batch mode is enabled but method needs interactive mode */ | |
1540 | if (method->batch_flag != NULL && *method->batch_flag != 0) | |
1541 | return 0; | |
1542 | return 1; | |
1543 | } | |
1544 | ||
1545 | static Authmethod * | |
1546 | authmethod_lookup(const char *name) | |
1547 | { | |
1548 | Authmethod *method = NULL; | |
1549 | if (name != NULL) | |
1550 | for (method = authmethods; method->name != NULL; method++) | |
1551 | if (strcmp(name, method->name) == 0) | |
1552 | return method; | |
1553 | debug2("Unrecognized authentication method name: %s", name ? name : "NULL"); | |
1554 | return NULL; | |
1555 | } | |
1556 | ||
1557 | /* XXX internal state */ | |
1558 | static Authmethod *current = NULL; | |
1559 | static char *supported = NULL; | |
1560 | static char *preferred = NULL; | |
680cee3b | 1561 | |
3c0ef626 | 1562 | /* |
1563 | * Given the authentication method list sent by the server, return the | |
1564 | * next method we should try. If the server initially sends a nil list, | |
1565 | * use a built-in default list. | |
1566 | */ | |
1567 | static Authmethod * | |
1568 | authmethod_get(char *authlist) | |
1569 | { | |
3c0ef626 | 1570 | char *name = NULL; |
e9a17296 | 1571 | u_int next; |
3c0ef626 | 1572 | |
1573 | /* Use a suitable default if we're passed a nil list. */ | |
1574 | if (authlist == NULL || strlen(authlist) == 0) | |
1575 | authlist = options.preferred_authentications; | |
1576 | ||
1577 | if (supported == NULL || strcmp(authlist, supported) != 0) { | |
1578 | debug3("start over, passed a different list %s", authlist); | |
1579 | if (supported != NULL) | |
1580 | xfree(supported); | |
1581 | supported = xstrdup(authlist); | |
1582 | preferred = options.preferred_authentications; | |
1583 | debug3("preferred %s", preferred); | |
1584 | current = NULL; | |
1585 | } else if (current != NULL && authmethod_is_enabled(current)) | |
1586 | return current; | |
1587 | ||
1588 | for (;;) { | |
1589 | if ((name = match_list(preferred, supported, &next)) == NULL) { | |
6a9b3198 | 1590 | debug("No more authentication methods to try."); |
3c0ef626 | 1591 | current = NULL; |
1592 | return NULL; | |
1593 | } | |
1594 | preferred += next; | |
1595 | debug3("authmethod_lookup %s", name); | |
1596 | debug3("remaining preferred: %s", preferred); | |
1597 | if ((current = authmethod_lookup(name)) != NULL && | |
1598 | authmethod_is_enabled(current)) { | |
1599 | debug3("authmethod_is_enabled %s", name); | |
6a9b3198 | 1600 | debug("Next authentication method: %s", name); |
3c0ef626 | 1601 | return current; |
1602 | } | |
1603 | } | |
1604 | } | |
1605 | ||
3c0ef626 | 1606 | static char * |
1607 | authmethods_get(void) | |
1608 | { | |
1609 | Authmethod *method = NULL; | |
e9a17296 | 1610 | Buffer b; |
1611 | char *list; | |
3c0ef626 | 1612 | |
e9a17296 | 1613 | buffer_init(&b); |
3c0ef626 | 1614 | for (method = authmethods; method->name != NULL; method++) { |
1615 | if (authmethod_is_enabled(method)) { | |
e9a17296 | 1616 | if (buffer_len(&b) > 0) |
1617 | buffer_append(&b, ",", 1); | |
1618 | buffer_append(&b, method->name, strlen(method->name)); | |
3c0ef626 | 1619 | } |
1620 | } | |
e9a17296 | 1621 | buffer_append(&b, "\0", 1); |
1622 | list = xstrdup(buffer_ptr(&b)); | |
1623 | buffer_free(&b); | |
1624 | return list; | |
3c0ef626 | 1625 | } |