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22616013 | 1 | /* $OpenBSD: sshconnect2.c,v 1.166 2008/07/17 08:48:00 djm 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> | |
d4487008 | 34 | #include <netdb.h> |
9108f8d9 | 35 | #include <pwd.h> |
36 | #include <signal.h> | |
37 | #include <stdarg.h> | |
38 | #include <stdio.h> | |
39 | #include <string.h> | |
40 | #include <unistd.h> | |
22616013 | 41 | #if defined(HAVE_STRNVIS) && defined(HAVE_VIS_H) |
42 | #include <vis.h> | |
43 | #endif | |
0fff78ff | 44 | |
45 | #include "openbsd-compat/sys-queue.h" | |
3c0ef626 | 46 | |
9108f8d9 | 47 | #include "xmalloc.h" |
3c0ef626 | 48 | #include "ssh.h" |
49 | #include "ssh2.h" | |
3c0ef626 | 50 | #include "buffer.h" |
51 | #include "packet.h" | |
3c0ef626 | 52 | #include "compat.h" |
3c0ef626 | 53 | #include "cipher.h" |
9108f8d9 | 54 | #include "key.h" |
3c0ef626 | 55 | #include "kex.h" |
56 | #include "myproposal.h" | |
3c0ef626 | 57 | #include "sshconnect.h" |
58 | #include "authfile.h" | |
59 | #include "dh.h" | |
60 | #include "authfd.h" | |
61 | #include "log.h" | |
62 | #include "readconf.h" | |
c9f39d2c | 63 | #include "misc.h" |
3c0ef626 | 64 | #include "match.h" |
65 | #include "dispatch.h" | |
66 | #include "canohost.h" | |
f5799ae1 | 67 | #include "msg.h" |
68 | #include "pathnames.h" | |
9108f8d9 | 69 | #include "uidswap.h" |
3c0ef626 | 70 | |
0fff78ff | 71 | #ifdef GSSAPI |
72 | #include "ssh-gss.h" | |
73 | #endif | |
74 | ||
3c0ef626 | 75 | /* import */ |
76 | extern char *client_version_string; | |
77 | extern char *server_version_string; | |
78 | extern Options options; | |
79 | ||
80 | /* | |
81 | * SSH2 key exchange | |
82 | */ | |
83 | ||
84 | u_char *session_id2 = NULL; | |
0fff78ff | 85 | u_int session_id2_len = 0; |
3c0ef626 | 86 | |
87 | char *xxx_host; | |
88 | struct sockaddr *xxx_hostaddr; | |
89 | ||
90 | Kex *xxx_kex = NULL; | |
91 | ||
92 | static int | |
93 | verify_host_key_callback(Key *hostkey) | |
94 | { | |
95 | if (verify_host_key(xxx_host, xxx_hostaddr, hostkey) == -1) | |
96 | fatal("Host key verification failed."); | |
97 | return 0; | |
98 | } | |
99 | ||
100 | void | |
101 | ssh_kex2(char *host, struct sockaddr *hostaddr) | |
102 | { | |
103 | Kex *kex; | |
104 | ||
105 | xxx_host = host; | |
106 | xxx_hostaddr = hostaddr; | |
107 | ||
108 | if (options.ciphers == (char *)-1) { | |
0fff78ff | 109 | logit("No valid ciphers for protocol version 2 given, using defaults."); |
3c0ef626 | 110 | options.ciphers = NULL; |
111 | } | |
112 | if (options.ciphers != NULL) { | |
113 | myproposal[PROPOSAL_ENC_ALGS_CTOS] = | |
114 | myproposal[PROPOSAL_ENC_ALGS_STOC] = options.ciphers; | |
115 | } | |
116 | myproposal[PROPOSAL_ENC_ALGS_CTOS] = | |
117 | compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_CTOS]); | |
118 | myproposal[PROPOSAL_ENC_ALGS_STOC] = | |
119 | compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_STOC]); | |
120 | if (options.compression) { | |
121 | myproposal[PROPOSAL_COMP_ALGS_CTOS] = | |
665a873d | 122 | myproposal[PROPOSAL_COMP_ALGS_STOC] = "zlib@openssh.com,zlib,none"; |
3c0ef626 | 123 | } else { |
124 | myproposal[PROPOSAL_COMP_ALGS_CTOS] = | |
665a873d | 125 | myproposal[PROPOSAL_COMP_ALGS_STOC] = "none,zlib@openssh.com,zlib"; |
3c0ef626 | 126 | } |
127 | if (options.macs != NULL) { | |
128 | myproposal[PROPOSAL_MAC_ALGS_CTOS] = | |
129 | myproposal[PROPOSAL_MAC_ALGS_STOC] = options.macs; | |
130 | } | |
131 | if (options.hostkeyalgorithms != NULL) | |
e9a17296 | 132 | myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = |
3c0ef626 | 133 | options.hostkeyalgorithms; |
134 | ||
0fff78ff | 135 | if (options.rekey_limit) |
47686178 | 136 | packet_set_rekey_limit((u_int32_t)options.rekey_limit); |
0fff78ff | 137 | |
3c0ef626 | 138 | /* start key exchange */ |
139 | kex = kex_setup(myproposal); | |
6a9b3198 | 140 | kex->kex[KEX_DH_GRP1_SHA1] = kexdh_client; |
c9f39d2c | 141 | kex->kex[KEX_DH_GRP14_SHA1] = kexdh_client; |
6a9b3198 | 142 | kex->kex[KEX_DH_GEX_SHA1] = kexgex_client; |
9108f8d9 | 143 | kex->kex[KEX_DH_GEX_SHA256] = kexgex_client; |
3c0ef626 | 144 | kex->client_version_string=client_version_string; |
145 | kex->server_version_string=server_version_string; | |
146 | kex->verify_host_key=&verify_host_key_callback; | |
147 | ||
148 | xxx_kex = kex; | |
149 | ||
150 | dispatch_run(DISPATCH_BLOCK, &kex->done, kex); | |
151 | ||
152 | session_id2 = kex->session_id; | |
153 | session_id2_len = kex->session_id_len; | |
154 | ||
155 | #ifdef DEBUG_KEXDH | |
156 | /* send 1st encrypted/maced/compressed message */ | |
157 | packet_start(SSH2_MSG_IGNORE); | |
158 | packet_put_cstring("markus"); | |
159 | packet_send(); | |
160 | packet_write_wait(); | |
161 | #endif | |
3c0ef626 | 162 | } |
163 | ||
164 | /* | |
165 | * Authenticate user | |
166 | */ | |
167 | ||
168 | typedef struct Authctxt Authctxt; | |
169 | typedef struct Authmethod Authmethod; | |
0fff78ff | 170 | typedef struct identity Identity; |
171 | typedef struct idlist Idlist; | |
172 | ||
173 | struct identity { | |
174 | TAILQ_ENTRY(identity) next; | |
175 | AuthenticationConnection *ac; /* set if agent supports key */ | |
176 | Key *key; /* public/private key */ | |
177 | char *filename; /* comment for agent-only keys */ | |
178 | int tried; | |
179 | int isprivate; /* key points to the private key */ | |
180 | }; | |
181 | TAILQ_HEAD(idlist, identity); | |
3c0ef626 | 182 | |
183 | struct Authctxt { | |
184 | const char *server_user; | |
185 | const char *local_user; | |
186 | const char *host; | |
187 | const char *service; | |
188 | Authmethod *method; | |
189 | int success; | |
190 | char *authlist; | |
191 | /* pubkey */ | |
0fff78ff | 192 | Idlist keys; |
3c0ef626 | 193 | AuthenticationConnection *agent; |
194 | /* hostbased */ | |
f5799ae1 | 195 | Sensitive *sensitive; |
3c0ef626 | 196 | /* kbd-interactive */ |
197 | int info_req_seen; | |
0fff78ff | 198 | /* generic */ |
199 | void *methoddata; | |
3c0ef626 | 200 | }; |
201 | struct Authmethod { | |
202 | char *name; /* string to compare against server's list */ | |
203 | int (*userauth)(Authctxt *authctxt); | |
204 | int *enabled; /* flag in option struct that enables method */ | |
205 | int *batch_flag; /* flag in option struct that disables method */ | |
206 | }; | |
207 | ||
e9a17296 | 208 | void input_userauth_success(int, u_int32_t, void *); |
209 | void input_userauth_failure(int, u_int32_t, void *); | |
210 | void input_userauth_banner(int, u_int32_t, void *); | |
211 | void input_userauth_error(int, u_int32_t, void *); | |
212 | void input_userauth_info_req(int, u_int32_t, void *); | |
213 | void input_userauth_pk_ok(int, u_int32_t, void *); | |
700318f3 | 214 | void input_userauth_passwd_changereq(int, u_int32_t, void *); |
3c0ef626 | 215 | |
e9a17296 | 216 | int userauth_none(Authctxt *); |
217 | int userauth_pubkey(Authctxt *); | |
218 | int userauth_passwd(Authctxt *); | |
219 | int userauth_kbdint(Authctxt *); | |
220 | int userauth_hostbased(Authctxt *); | |
0fff78ff | 221 | int userauth_kerberos(Authctxt *); |
222 | ||
223 | #ifdef GSSAPI | |
224 | int userauth_gssapi(Authctxt *authctxt); | |
225 | void input_gssapi_response(int type, u_int32_t, void *); | |
226 | void input_gssapi_token(int type, u_int32_t, void *); | |
227 | void input_gssapi_hash(int type, u_int32_t, void *); | |
228 | void input_gssapi_error(int, u_int32_t, void *); | |
229 | void input_gssapi_errtok(int, u_int32_t, void *); | |
230 | #endif | |
3c0ef626 | 231 | |
e9a17296 | 232 | void userauth(Authctxt *, char *); |
3c0ef626 | 233 | |
0fff78ff | 234 | static int sign_and_send_pubkey(Authctxt *, Identity *); |
235 | static void pubkey_prepare(Authctxt *); | |
236 | static void pubkey_cleanup(Authctxt *); | |
237 | static Key *load_identity_file(char *); | |
3c0ef626 | 238 | |
239 | static Authmethod *authmethod_get(char *authlist); | |
240 | static Authmethod *authmethod_lookup(const char *name); | |
241 | static char *authmethods_get(void); | |
242 | ||
243 | Authmethod authmethods[] = { | |
0fff78ff | 244 | #ifdef GSSAPI |
cdd66111 | 245 | {"gssapi-with-mic", |
0fff78ff | 246 | userauth_gssapi, |
247 | &options.gss_authentication, | |
248 | NULL}, | |
249 | #endif | |
3c0ef626 | 250 | {"hostbased", |
251 | userauth_hostbased, | |
252 | &options.hostbased_authentication, | |
253 | NULL}, | |
254 | {"publickey", | |
255 | userauth_pubkey, | |
256 | &options.pubkey_authentication, | |
257 | NULL}, | |
258 | {"keyboard-interactive", | |
259 | userauth_kbdint, | |
260 | &options.kbd_interactive_authentication, | |
261 | &options.batch_mode}, | |
262 | {"password", | |
263 | userauth_passwd, | |
264 | &options.password_authentication, | |
265 | &options.batch_mode}, | |
266 | {"none", | |
267 | userauth_none, | |
268 | NULL, | |
269 | NULL}, | |
270 | {NULL, NULL, NULL, NULL} | |
271 | }; | |
272 | ||
273 | void | |
274 | ssh_userauth2(const char *local_user, const char *server_user, char *host, | |
f5799ae1 | 275 | Sensitive *sensitive) |
3c0ef626 | 276 | { |
277 | Authctxt authctxt; | |
278 | int type; | |
3c0ef626 | 279 | |
280 | if (options.challenge_response_authentication) | |
281 | options.kbd_interactive_authentication = 1; | |
282 | ||
3c0ef626 | 283 | packet_start(SSH2_MSG_SERVICE_REQUEST); |
284 | packet_put_cstring("ssh-userauth"); | |
285 | packet_send(); | |
6a9b3198 | 286 | debug("SSH2_MSG_SERVICE_REQUEST sent"); |
3c0ef626 | 287 | packet_write_wait(); |
e9a17296 | 288 | type = packet_read(); |
6a9b3198 | 289 | if (type != SSH2_MSG_SERVICE_ACCEPT) |
290 | fatal("Server denied authentication request: %d", type); | |
3c0ef626 | 291 | if (packet_remaining() > 0) { |
e9a17296 | 292 | char *reply = packet_get_string(NULL); |
6a9b3198 | 293 | debug2("service_accept: %s", reply); |
3c0ef626 | 294 | xfree(reply); |
295 | } else { | |
6a9b3198 | 296 | debug2("buggy server: service_accept w/o service"); |
3c0ef626 | 297 | } |
e9a17296 | 298 | packet_check_eom(); |
6a9b3198 | 299 | debug("SSH2_MSG_SERVICE_ACCEPT received"); |
3c0ef626 | 300 | |
301 | if (options.preferred_authentications == NULL) | |
302 | options.preferred_authentications = authmethods_get(); | |
303 | ||
304 | /* setup authentication context */ | |
305 | memset(&authctxt, 0, sizeof(authctxt)); | |
0fff78ff | 306 | pubkey_prepare(&authctxt); |
3c0ef626 | 307 | authctxt.server_user = server_user; |
308 | authctxt.local_user = local_user; | |
309 | authctxt.host = host; | |
310 | authctxt.service = "ssh-connection"; /* service name */ | |
311 | authctxt.success = 0; | |
312 | authctxt.method = authmethod_lookup("none"); | |
313 | authctxt.authlist = NULL; | |
0fff78ff | 314 | authctxt.methoddata = NULL; |
f5799ae1 | 315 | authctxt.sensitive = sensitive; |
3c0ef626 | 316 | authctxt.info_req_seen = 0; |
317 | if (authctxt.method == NULL) | |
318 | fatal("ssh_userauth2: internal error: cannot send userauth none request"); | |
319 | ||
320 | /* initial userauth request */ | |
321 | userauth_none(&authctxt); | |
322 | ||
323 | dispatch_init(&input_userauth_error); | |
324 | dispatch_set(SSH2_MSG_USERAUTH_SUCCESS, &input_userauth_success); | |
325 | dispatch_set(SSH2_MSG_USERAUTH_FAILURE, &input_userauth_failure); | |
326 | dispatch_set(SSH2_MSG_USERAUTH_BANNER, &input_userauth_banner); | |
327 | dispatch_run(DISPATCH_BLOCK, &authctxt.success, &authctxt); /* loop until success */ | |
328 | ||
0fff78ff | 329 | pubkey_cleanup(&authctxt); |
330 | dispatch_range(SSH2_MSG_USERAUTH_MIN, SSH2_MSG_USERAUTH_MAX, NULL); | |
3c0ef626 | 331 | |
6a9b3198 | 332 | debug("Authentication succeeded (%s).", authctxt.method->name); |
3c0ef626 | 333 | } |
0fff78ff | 334 | |
3c0ef626 | 335 | void |
336 | userauth(Authctxt *authctxt, char *authlist) | |
337 | { | |
0fff78ff | 338 | if (authctxt->methoddata) { |
339 | xfree(authctxt->methoddata); | |
340 | authctxt->methoddata = NULL; | |
341 | } | |
3c0ef626 | 342 | if (authlist == NULL) { |
343 | authlist = authctxt->authlist; | |
344 | } else { | |
345 | if (authctxt->authlist) | |
346 | xfree(authctxt->authlist); | |
347 | authctxt->authlist = authlist; | |
348 | } | |
349 | for (;;) { | |
350 | Authmethod *method = authmethod_get(authlist); | |
351 | if (method == NULL) | |
352 | fatal("Permission denied (%s).", authlist); | |
353 | authctxt->method = method; | |
0fff78ff | 354 | |
355 | /* reset the per method handler */ | |
356 | dispatch_range(SSH2_MSG_USERAUTH_PER_METHOD_MIN, | |
357 | SSH2_MSG_USERAUTH_PER_METHOD_MAX, NULL); | |
358 | ||
359 | /* and try new method */ | |
3c0ef626 | 360 | if (method->userauth(authctxt) != 0) { |
361 | debug2("we sent a %s packet, wait for reply", method->name); | |
362 | break; | |
363 | } else { | |
364 | debug2("we did not send a packet, disable method"); | |
365 | method->enabled = NULL; | |
366 | } | |
367 | } | |
368 | } | |
680cee3b | 369 | |
3c0ef626 | 370 | void |
e9a17296 | 371 | input_userauth_error(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 372 | { |
373 | fatal("input_userauth_error: bad message during authentication: " | |
665a873d | 374 | "type %d", type); |
3c0ef626 | 375 | } |
680cee3b | 376 | |
3c0ef626 | 377 | void |
e9a17296 | 378 | input_userauth_banner(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 379 | { |
22616013 | 380 | char *msg, *raw, *lang; |
381 | u_int len; | |
cdd66111 | 382 | |
3c0ef626 | 383 | debug3("input_userauth_banner"); |
22616013 | 384 | raw = packet_get_string(&len); |
3c0ef626 | 385 | lang = packet_get_string(NULL); |
22616013 | 386 | if (options.log_level >= SYSLOG_LEVEL_INFO) { |
387 | if (len > 65536) | |
388 | len = 65536; | |
389 | msg = xmalloc(len * 4); /* max expansion from strnvis() */ | |
390 | strnvis(msg, raw, len * 4, VIS_SAFE|VIS_OCTAL); | |
cdd66111 | 391 | fprintf(stderr, "%s", msg); |
22616013 | 392 | xfree(msg); |
393 | } | |
394 | xfree(raw); | |
3c0ef626 | 395 | xfree(lang); |
396 | } | |
680cee3b | 397 | |
3c0ef626 | 398 | void |
e9a17296 | 399 | input_userauth_success(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 400 | { |
401 | Authctxt *authctxt = ctxt; | |
402 | if (authctxt == NULL) | |
403 | fatal("input_userauth_success: no authentication context"); | |
cdd66111 | 404 | if (authctxt->authlist) { |
3c0ef626 | 405 | xfree(authctxt->authlist); |
cdd66111 | 406 | authctxt->authlist = NULL; |
407 | } | |
408 | if (authctxt->methoddata) { | |
0fff78ff | 409 | xfree(authctxt->methoddata); |
cdd66111 | 410 | authctxt->methoddata = NULL; |
411 | } | |
3c0ef626 | 412 | authctxt->success = 1; /* break out */ |
413 | } | |
680cee3b | 414 | |
3c0ef626 | 415 | void |
e9a17296 | 416 | input_userauth_failure(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 417 | { |
418 | Authctxt *authctxt = ctxt; | |
419 | char *authlist = NULL; | |
420 | int partial; | |
421 | ||
422 | if (authctxt == NULL) | |
423 | fatal("input_userauth_failure: no authentication context"); | |
424 | ||
425 | authlist = packet_get_string(NULL); | |
426 | partial = packet_get_char(); | |
e9a17296 | 427 | packet_check_eom(); |
3c0ef626 | 428 | |
429 | if (partial != 0) | |
0fff78ff | 430 | logit("Authenticated with partial success."); |
6a9b3198 | 431 | debug("Authentications that can continue: %s", authlist); |
3c0ef626 | 432 | |
3c0ef626 | 433 | userauth(authctxt, authlist); |
434 | } | |
435 | void | |
e9a17296 | 436 | input_userauth_pk_ok(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 437 | { |
438 | Authctxt *authctxt = ctxt; | |
439 | Key *key = NULL; | |
0fff78ff | 440 | Identity *id = NULL; |
3c0ef626 | 441 | Buffer b; |
e9a17296 | 442 | int pktype, sent = 0; |
443 | u_int alen, blen; | |
444 | char *pkalg, *fp; | |
445 | u_char *pkblob; | |
3c0ef626 | 446 | |
447 | if (authctxt == NULL) | |
448 | fatal("input_userauth_pk_ok: no authentication context"); | |
449 | if (datafellows & SSH_BUG_PKOK) { | |
450 | /* this is similar to SSH_BUG_PKAUTH */ | |
451 | debug2("input_userauth_pk_ok: SSH_BUG_PKOK"); | |
452 | pkblob = packet_get_string(&blen); | |
453 | buffer_init(&b); | |
454 | buffer_append(&b, pkblob, blen); | |
455 | pkalg = buffer_get_string(&b, &alen); | |
456 | buffer_free(&b); | |
457 | } else { | |
458 | pkalg = packet_get_string(&alen); | |
459 | pkblob = packet_get_string(&blen); | |
460 | } | |
e9a17296 | 461 | packet_check_eom(); |
3c0ef626 | 462 | |
0fff78ff | 463 | debug("Server accepts key: pkalg %s blen %u", pkalg, blen); |
3c0ef626 | 464 | |
0fff78ff | 465 | if ((pktype = key_type_from_name(pkalg)) == KEY_UNSPEC) { |
466 | debug("unknown pkalg %s", pkalg); | |
467 | goto done; | |
468 | } | |
469 | if ((key = key_from_blob(pkblob, blen)) == NULL) { | |
470 | debug("no key from blob. pkalg %s", pkalg); | |
471 | goto done; | |
472 | } | |
473 | if (key->type != pktype) { | |
474 | error("input_userauth_pk_ok: type mismatch " | |
475 | "for decoded key (received %d, expected %d)", | |
476 | key->type, pktype); | |
477 | goto done; | |
478 | } | |
479 | fp = key_fingerprint(key, SSH_FP_MD5, SSH_FP_HEX); | |
480 | debug2("input_userauth_pk_ok: fp %s", fp); | |
481 | xfree(fp); | |
482 | ||
cdd66111 | 483 | /* |
484 | * search keys in the reverse order, because last candidate has been | |
485 | * moved to the end of the queue. this also avoids confusion by | |
486 | * duplicate keys | |
487 | */ | |
c9f39d2c | 488 | TAILQ_FOREACH_REVERSE(id, &authctxt->keys, idlist, next) { |
0fff78ff | 489 | if (key_equal(key, id->key)) { |
490 | sent = sign_and_send_pubkey(authctxt, id); | |
3c0ef626 | 491 | break; |
492 | } | |
0fff78ff | 493 | } |
494 | done: | |
3c0ef626 | 495 | if (key != NULL) |
496 | key_free(key); | |
497 | xfree(pkalg); | |
498 | xfree(pkblob); | |
499 | ||
41b2f314 | 500 | /* try another method if we did not send a packet */ |
3c0ef626 | 501 | if (sent == 0) |
502 | userauth(authctxt, NULL); | |
0fff78ff | 503 | } |
504 | ||
505 | #ifdef GSSAPI | |
cdd66111 | 506 | int |
0fff78ff | 507 | userauth_gssapi(Authctxt *authctxt) |
508 | { | |
509 | Gssctxt *gssctxt = NULL; | |
cdd66111 | 510 | static gss_OID_set gss_supported = NULL; |
665a873d | 511 | static u_int mech = 0; |
0fff78ff | 512 | OM_uint32 min; |
513 | int ok = 0; | |
514 | ||
515 | /* Try one GSSAPI method at a time, rather than sending them all at | |
516 | * once. */ | |
517 | ||
cdd66111 | 518 | if (gss_supported == NULL) |
519 | gss_indicate_mechs(&min, &gss_supported); | |
0fff78ff | 520 | |
521 | /* Check to see if the mechanism is usable before we offer it */ | |
cdd66111 | 522 | while (mech < gss_supported->count && !ok) { |
0fff78ff | 523 | /* My DER encoding requires length<128 */ |
cdd66111 | 524 | if (gss_supported->elements[mech].length < 128 && |
9108f8d9 | 525 | ssh_gssapi_check_mechanism(&gssctxt, |
526 | &gss_supported->elements[mech], authctxt->host)) { | |
0fff78ff | 527 | ok = 1; /* Mechanism works */ |
528 | } else { | |
529 | mech++; | |
530 | } | |
531 | } | |
532 | ||
665a873d | 533 | if (!ok) |
534 | return 0; | |
0fff78ff | 535 | |
536 | authctxt->methoddata=(void *)gssctxt; | |
537 | ||
538 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
539 | packet_put_cstring(authctxt->server_user); | |
540 | packet_put_cstring(authctxt->service); | |
541 | packet_put_cstring(authctxt->method->name); | |
542 | ||
543 | packet_put_int(1); | |
544 | ||
cdd66111 | 545 | packet_put_int((gss_supported->elements[mech].length) + 2); |
546 | packet_put_char(SSH_GSS_OIDTYPE); | |
547 | packet_put_char(gss_supported->elements[mech].length); | |
548 | packet_put_raw(gss_supported->elements[mech].elements, | |
549 | gss_supported->elements[mech].length); | |
0fff78ff | 550 | |
551 | packet_send(); | |
552 | ||
553 | dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE, &input_gssapi_response); | |
554 | dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, &input_gssapi_token); | |
555 | dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERROR, &input_gssapi_error); | |
556 | dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, &input_gssapi_errtok); | |
557 | ||
558 | mech++; /* Move along to next candidate */ | |
559 | ||
560 | return 1; | |
561 | } | |
562 | ||
cdd66111 | 563 | static OM_uint32 |
564 | process_gssapi_token(void *ctxt, gss_buffer_t recv_tok) | |
565 | { | |
566 | Authctxt *authctxt = ctxt; | |
567 | Gssctxt *gssctxt = authctxt->methoddata; | |
568 | gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER; | |
665a873d | 569 | gss_buffer_desc mic = GSS_C_EMPTY_BUFFER; |
570 | gss_buffer_desc gssbuf; | |
cdd66111 | 571 | OM_uint32 status, ms, flags; |
572 | Buffer b; | |
573 | ||
574 | status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds, | |
575 | recv_tok, &send_tok, &flags); | |
576 | ||
577 | if (send_tok.length > 0) { | |
578 | if (GSS_ERROR(status)) | |
579 | packet_start(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK); | |
580 | else | |
581 | packet_start(SSH2_MSG_USERAUTH_GSSAPI_TOKEN); | |
582 | ||
583 | packet_put_string(send_tok.value, send_tok.length); | |
584 | packet_send(); | |
585 | gss_release_buffer(&ms, &send_tok); | |
586 | } | |
587 | ||
588 | if (status == GSS_S_COMPLETE) { | |
589 | /* send either complete or MIC, depending on mechanism */ | |
590 | if (!(flags & GSS_C_INTEG_FLAG)) { | |
591 | packet_start(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE); | |
592 | packet_send(); | |
593 | } else { | |
594 | ssh_gssapi_buildmic(&b, authctxt->server_user, | |
595 | authctxt->service, "gssapi-with-mic"); | |
596 | ||
597 | gssbuf.value = buffer_ptr(&b); | |
598 | gssbuf.length = buffer_len(&b); | |
599 | ||
600 | status = ssh_gssapi_sign(gssctxt, &gssbuf, &mic); | |
601 | ||
602 | if (!GSS_ERROR(status)) { | |
603 | packet_start(SSH2_MSG_USERAUTH_GSSAPI_MIC); | |
604 | packet_put_string(mic.value, mic.length); | |
605 | ||
606 | packet_send(); | |
607 | } | |
608 | ||
609 | buffer_free(&b); | |
610 | gss_release_buffer(&ms, &mic); | |
611 | } | |
612 | } | |
613 | ||
614 | return status; | |
615 | } | |
616 | ||
0fff78ff | 617 | void |
618 | input_gssapi_response(int type, u_int32_t plen, void *ctxt) | |
619 | { | |
620 | Authctxt *authctxt = ctxt; | |
621 | Gssctxt *gssctxt; | |
0fff78ff | 622 | int oidlen; |
623 | char *oidv; | |
0fff78ff | 624 | |
625 | if (authctxt == NULL) | |
626 | fatal("input_gssapi_response: no authentication context"); | |
627 | gssctxt = authctxt->methoddata; | |
628 | ||
629 | /* Setup our OID */ | |
630 | oidv = packet_get_string(&oidlen); | |
631 | ||
cdd66111 | 632 | if (oidlen <= 2 || |
633 | oidv[0] != SSH_GSS_OIDTYPE || | |
634 | oidv[1] != oidlen - 2) { | |
635 | xfree(oidv); | |
636 | debug("Badly encoded mechanism OID received"); | |
637 | userauth(authctxt, NULL); | |
638 | return; | |
0fff78ff | 639 | } |
640 | ||
cdd66111 | 641 | if (!ssh_gssapi_check_oid(gssctxt, oidv + 2, oidlen - 2)) |
642 | fatal("Server returned different OID than expected"); | |
643 | ||
0fff78ff | 644 | packet_check_eom(); |
645 | ||
646 | xfree(oidv); | |
647 | ||
cdd66111 | 648 | if (GSS_ERROR(process_gssapi_token(ctxt, GSS_C_NO_BUFFER))) { |
0fff78ff | 649 | /* Start again with next method on list */ |
650 | debug("Trying to start again"); | |
651 | userauth(authctxt, NULL); | |
652 | return; | |
653 | } | |
0fff78ff | 654 | } |
655 | ||
656 | void | |
657 | input_gssapi_token(int type, u_int32_t plen, void *ctxt) | |
658 | { | |
659 | Authctxt *authctxt = ctxt; | |
0fff78ff | 660 | gss_buffer_desc recv_tok; |
cdd66111 | 661 | OM_uint32 status; |
0fff78ff | 662 | u_int slen; |
663 | ||
664 | if (authctxt == NULL) | |
665 | fatal("input_gssapi_response: no authentication context"); | |
0fff78ff | 666 | |
667 | recv_tok.value = packet_get_string(&slen); | |
668 | recv_tok.length = slen; /* safe typecast */ | |
669 | ||
670 | packet_check_eom(); | |
671 | ||
cdd66111 | 672 | status = process_gssapi_token(ctxt, &recv_tok); |
0fff78ff | 673 | |
674 | xfree(recv_tok.value); | |
675 | ||
676 | if (GSS_ERROR(status)) { | |
0fff78ff | 677 | /* Start again with the next method in the list */ |
678 | userauth(authctxt, NULL); | |
679 | return; | |
680 | } | |
3c0ef626 | 681 | } |
682 | ||
0fff78ff | 683 | void |
684 | input_gssapi_errtok(int type, u_int32_t plen, void *ctxt) | |
685 | { | |
686 | Authctxt *authctxt = ctxt; | |
687 | Gssctxt *gssctxt; | |
688 | gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER; | |
689 | gss_buffer_desc recv_tok; | |
690 | OM_uint32 status, ms; | |
691 | u_int len; | |
692 | ||
693 | if (authctxt == NULL) | |
694 | fatal("input_gssapi_response: no authentication context"); | |
695 | gssctxt = authctxt->methoddata; | |
696 | ||
697 | recv_tok.value = packet_get_string(&len); | |
698 | recv_tok.length = len; | |
699 | ||
700 | packet_check_eom(); | |
701 | ||
702 | /* Stick it into GSSAPI and see what it says */ | |
703 | status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds, | |
665a873d | 704 | &recv_tok, &send_tok, NULL); |
0fff78ff | 705 | |
706 | xfree(recv_tok.value); | |
707 | gss_release_buffer(&ms, &send_tok); | |
708 | ||
709 | /* Server will be returning a failed packet after this one */ | |
710 | } | |
711 | ||
712 | void | |
713 | input_gssapi_error(int type, u_int32_t plen, void *ctxt) | |
714 | { | |
715 | OM_uint32 maj, min; | |
716 | char *msg; | |
717 | char *lang; | |
718 | ||
719 | maj=packet_get_int(); | |
720 | min=packet_get_int(); | |
721 | msg=packet_get_string(NULL); | |
722 | lang=packet_get_string(NULL); | |
723 | ||
724 | packet_check_eom(); | |
725 | ||
2c06c99b | 726 | debug("Server GSSAPI Error:\n%s", msg); |
0fff78ff | 727 | xfree(msg); |
728 | xfree(lang); | |
729 | } | |
730 | #endif /* GSSAPI */ | |
731 | ||
3c0ef626 | 732 | int |
733 | userauth_none(Authctxt *authctxt) | |
734 | { | |
735 | /* initial userauth request */ | |
736 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
737 | packet_put_cstring(authctxt->server_user); | |
738 | packet_put_cstring(authctxt->service); | |
739 | packet_put_cstring(authctxt->method->name); | |
740 | packet_send(); | |
741 | return 1; | |
742 | } | |
743 | ||
744 | int | |
745 | userauth_passwd(Authctxt *authctxt) | |
746 | { | |
747 | static int attempt = 0; | |
700318f3 | 748 | char prompt[150]; |
3c0ef626 | 749 | char *password; |
750 | ||
751 | if (attempt++ >= options.number_of_password_prompts) | |
752 | return 0; | |
753 | ||
e9a17296 | 754 | if (attempt != 1) |
3c0ef626 | 755 | error("Permission denied, please try again."); |
756 | ||
757 | snprintf(prompt, sizeof(prompt), "%.30s@%.128s's password: ", | |
758 | authctxt->server_user, authctxt->host); | |
759 | password = read_passphrase(prompt, 0); | |
760 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
761 | packet_put_cstring(authctxt->server_user); | |
762 | packet_put_cstring(authctxt->service); | |
763 | packet_put_cstring(authctxt->method->name); | |
764 | packet_put_char(0); | |
765 | packet_put_cstring(password); | |
766 | memset(password, 0, strlen(password)); | |
767 | xfree(password); | |
768 | packet_add_padding(64); | |
769 | packet_send(); | |
700318f3 | 770 | |
f5799ae1 | 771 | dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, |
700318f3 | 772 | &input_userauth_passwd_changereq); |
773 | ||
3c0ef626 | 774 | return 1; |
775 | } | |
700318f3 | 776 | /* |
777 | * parse PASSWD_CHANGEREQ, prompt user and send SSH2_MSG_USERAUTH_REQUEST | |
778 | */ | |
779 | void | |
780 | input_userauth_passwd_changereq(int type, u_int32_t seqnr, void *ctxt) | |
781 | { | |
782 | Authctxt *authctxt = ctxt; | |
783 | char *info, *lang, *password = NULL, *retype = NULL; | |
784 | char prompt[150]; | |
785 | ||
786 | debug2("input_userauth_passwd_changereq"); | |
787 | ||
788 | if (authctxt == NULL) | |
789 | fatal("input_userauth_passwd_changereq: " | |
790 | "no authentication context"); | |
791 | ||
792 | info = packet_get_string(NULL); | |
793 | lang = packet_get_string(NULL); | |
794 | if (strlen(info) > 0) | |
0fff78ff | 795 | logit("%s", info); |
700318f3 | 796 | xfree(info); |
797 | xfree(lang); | |
798 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
799 | packet_put_cstring(authctxt->server_user); | |
800 | packet_put_cstring(authctxt->service); | |
801 | packet_put_cstring(authctxt->method->name); | |
802 | packet_put_char(1); /* additional info */ | |
f5799ae1 | 803 | snprintf(prompt, sizeof(prompt), |
700318f3 | 804 | "Enter %.30s@%.128s's old password: ", |
805 | authctxt->server_user, authctxt->host); | |
806 | password = read_passphrase(prompt, 0); | |
807 | packet_put_cstring(password); | |
808 | memset(password, 0, strlen(password)); | |
809 | xfree(password); | |
810 | password = NULL; | |
811 | while (password == NULL) { | |
f5799ae1 | 812 | snprintf(prompt, sizeof(prompt), |
700318f3 | 813 | "Enter %.30s@%.128s's new password: ", |
814 | authctxt->server_user, authctxt->host); | |
815 | password = read_passphrase(prompt, RP_ALLOW_EOF); | |
816 | if (password == NULL) { | |
817 | /* bail out */ | |
818 | return; | |
819 | } | |
f5799ae1 | 820 | snprintf(prompt, sizeof(prompt), |
700318f3 | 821 | "Retype %.30s@%.128s's new password: ", |
822 | authctxt->server_user, authctxt->host); | |
823 | retype = read_passphrase(prompt, 0); | |
824 | if (strcmp(password, retype) != 0) { | |
825 | memset(password, 0, strlen(password)); | |
826 | xfree(password); | |
0fff78ff | 827 | logit("Mismatch; try again, EOF to quit."); |
700318f3 | 828 | password = NULL; |
829 | } | |
830 | memset(retype, 0, strlen(retype)); | |
831 | xfree(retype); | |
832 | } | |
833 | packet_put_cstring(password); | |
834 | memset(password, 0, strlen(password)); | |
835 | xfree(password); | |
836 | packet_add_padding(64); | |
837 | packet_send(); | |
f5799ae1 | 838 | |
839 | dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, | |
700318f3 | 840 | &input_userauth_passwd_changereq); |
841 | } | |
3c0ef626 | 842 | |
0fff78ff | 843 | static int |
844 | identity_sign(Identity *id, u_char **sigp, u_int *lenp, | |
845 | u_char *data, u_int datalen) | |
3c0ef626 | 846 | { |
0fff78ff | 847 | Key *prv; |
848 | int ret; | |
700318f3 | 849 | |
0fff78ff | 850 | /* the agent supports this key */ |
851 | if (id->ac) | |
852 | return (ssh_agent_sign(id->ac, id->key, sigp, lenp, | |
853 | data, datalen)); | |
854 | /* | |
855 | * we have already loaded the private key or | |
856 | * the private key is stored in external hardware | |
857 | */ | |
858 | if (id->isprivate || (id->key->flags & KEY_FLAG_EXT)) | |
859 | return (key_sign(id->key, sigp, lenp, data, datalen)); | |
860 | /* load the private key from the file */ | |
861 | if ((prv = load_identity_file(id->filename)) == NULL) | |
862 | return (-1); | |
863 | ret = key_sign(prv, sigp, lenp, data, datalen); | |
864 | key_free(prv); | |
865 | return (ret); | |
3c0ef626 | 866 | } |
867 | ||
868 | static int | |
0fff78ff | 869 | sign_and_send_pubkey(Authctxt *authctxt, Identity *id) |
3c0ef626 | 870 | { |
871 | Buffer b; | |
872 | u_char *blob, *signature; | |
e9a17296 | 873 | u_int bloblen, slen; |
0fff78ff | 874 | u_int skip = 0; |
3c0ef626 | 875 | int ret = -1; |
876 | int have_sig = 1; | |
877 | ||
878 | debug3("sign_and_send_pubkey"); | |
879 | ||
0fff78ff | 880 | if (key_to_blob(id->key, &blob, &bloblen) == 0) { |
3c0ef626 | 881 | /* we cannot handle this key */ |
882 | debug3("sign_and_send_pubkey: cannot handle key"); | |
883 | return 0; | |
884 | } | |
885 | /* data to be signed */ | |
886 | buffer_init(&b); | |
887 | if (datafellows & SSH_OLD_SESSIONID) { | |
888 | buffer_append(&b, session_id2, session_id2_len); | |
889 | skip = session_id2_len; | |
890 | } else { | |
891 | buffer_put_string(&b, session_id2, session_id2_len); | |
892 | skip = buffer_len(&b); | |
893 | } | |
894 | buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST); | |
895 | buffer_put_cstring(&b, authctxt->server_user); | |
896 | buffer_put_cstring(&b, | |
897 | datafellows & SSH_BUG_PKSERVICE ? | |
898 | "ssh-userauth" : | |
899 | authctxt->service); | |
900 | if (datafellows & SSH_BUG_PKAUTH) { | |
901 | buffer_put_char(&b, have_sig); | |
902 | } else { | |
903 | buffer_put_cstring(&b, authctxt->method->name); | |
904 | buffer_put_char(&b, have_sig); | |
0fff78ff | 905 | buffer_put_cstring(&b, key_ssh_name(id->key)); |
3c0ef626 | 906 | } |
907 | buffer_put_string(&b, blob, bloblen); | |
908 | ||
909 | /* generate signature */ | |
0fff78ff | 910 | ret = identity_sign(id, &signature, &slen, |
3c0ef626 | 911 | buffer_ptr(&b), buffer_len(&b)); |
912 | if (ret == -1) { | |
913 | xfree(blob); | |
914 | buffer_free(&b); | |
915 | return 0; | |
916 | } | |
917 | #ifdef DEBUG_PK | |
918 | buffer_dump(&b); | |
919 | #endif | |
920 | if (datafellows & SSH_BUG_PKSERVICE) { | |
921 | buffer_clear(&b); | |
922 | buffer_append(&b, session_id2, session_id2_len); | |
923 | skip = session_id2_len; | |
924 | buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST); | |
925 | buffer_put_cstring(&b, authctxt->server_user); | |
926 | buffer_put_cstring(&b, authctxt->service); | |
927 | buffer_put_cstring(&b, authctxt->method->name); | |
928 | buffer_put_char(&b, have_sig); | |
929 | if (!(datafellows & SSH_BUG_PKAUTH)) | |
0fff78ff | 930 | buffer_put_cstring(&b, key_ssh_name(id->key)); |
3c0ef626 | 931 | buffer_put_string(&b, blob, bloblen); |
932 | } | |
933 | xfree(blob); | |
934 | ||
935 | /* append signature */ | |
936 | buffer_put_string(&b, signature, slen); | |
937 | xfree(signature); | |
938 | ||
939 | /* skip session id and packet type */ | |
940 | if (buffer_len(&b) < skip + 1) | |
941 | fatal("userauth_pubkey: internal error"); | |
942 | buffer_consume(&b, skip + 1); | |
943 | ||
944 | /* put remaining data from buffer into packet */ | |
945 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
946 | packet_put_raw(buffer_ptr(&b), buffer_len(&b)); | |
947 | buffer_free(&b); | |
948 | packet_send(); | |
949 | ||
950 | return 1; | |
951 | } | |
952 | ||
953 | static int | |
0fff78ff | 954 | send_pubkey_test(Authctxt *authctxt, Identity *id) |
3c0ef626 | 955 | { |
956 | u_char *blob; | |
e9a17296 | 957 | u_int bloblen, have_sig = 0; |
3c0ef626 | 958 | |
959 | debug3("send_pubkey_test"); | |
960 | ||
0fff78ff | 961 | if (key_to_blob(id->key, &blob, &bloblen) == 0) { |
3c0ef626 | 962 | /* we cannot handle this key */ |
963 | debug3("send_pubkey_test: cannot handle key"); | |
964 | return 0; | |
965 | } | |
966 | /* register callback for USERAUTH_PK_OK message */ | |
3c0ef626 | 967 | dispatch_set(SSH2_MSG_USERAUTH_PK_OK, &input_userauth_pk_ok); |
968 | ||
969 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
970 | packet_put_cstring(authctxt->server_user); | |
971 | packet_put_cstring(authctxt->service); | |
972 | packet_put_cstring(authctxt->method->name); | |
973 | packet_put_char(have_sig); | |
974 | if (!(datafellows & SSH_BUG_PKAUTH)) | |
0fff78ff | 975 | packet_put_cstring(key_ssh_name(id->key)); |
3c0ef626 | 976 | packet_put_string(blob, bloblen); |
977 | xfree(blob); | |
978 | packet_send(); | |
979 | return 1; | |
980 | } | |
981 | ||
982 | static Key * | |
983 | load_identity_file(char *filename) | |
984 | { | |
985 | Key *private; | |
986 | char prompt[300], *passphrase; | |
9108f8d9 | 987 | int perm_ok, quit, i; |
3c0ef626 | 988 | struct stat st; |
989 | ||
990 | if (stat(filename, &st) < 0) { | |
991 | debug3("no such identity: %s", filename); | |
992 | return NULL; | |
993 | } | |
9108f8d9 | 994 | private = key_load_private_type(KEY_UNSPEC, filename, "", NULL, &perm_ok); |
995 | if (!perm_ok) | |
996 | return NULL; | |
3c0ef626 | 997 | if (private == NULL) { |
998 | if (options.batch_mode) | |
999 | return NULL; | |
1000 | snprintf(prompt, sizeof prompt, | |
e9a17296 | 1001 | "Enter passphrase for key '%.100s': ", filename); |
3c0ef626 | 1002 | for (i = 0; i < options.number_of_password_prompts; i++) { |
1003 | passphrase = read_passphrase(prompt, 0); | |
1004 | if (strcmp(passphrase, "") != 0) { | |
9108f8d9 | 1005 | private = key_load_private_type(KEY_UNSPEC, |
1006 | filename, passphrase, NULL, NULL); | |
3c0ef626 | 1007 | quit = 0; |
1008 | } else { | |
1009 | debug2("no passphrase given, try next key"); | |
1010 | quit = 1; | |
1011 | } | |
1012 | memset(passphrase, 0, strlen(passphrase)); | |
1013 | xfree(passphrase); | |
1014 | if (private != NULL || quit) | |
1015 | break; | |
1016 | debug2("bad passphrase given, try again..."); | |
1017 | } | |
1018 | } | |
1019 | return private; | |
1020 | } | |
1021 | ||
0fff78ff | 1022 | /* |
1023 | * try keys in the following order: | |
1024 | * 1. agent keys that are found in the config file | |
1025 | * 2. other agent keys | |
1026 | * 3. keys that are only listed in the config file | |
1027 | */ | |
1028 | static void | |
1029 | pubkey_prepare(Authctxt *authctxt) | |
3c0ef626 | 1030 | { |
0fff78ff | 1031 | Identity *id; |
1032 | Idlist agent, files, *preferred; | |
1033 | Key *key; | |
1034 | AuthenticationConnection *ac; | |
1035 | char *comment; | |
1036 | int i, found; | |
1037 | ||
1038 | TAILQ_INIT(&agent); /* keys from the agent */ | |
1039 | TAILQ_INIT(&files); /* keys from the config file */ | |
1040 | preferred = &authctxt->keys; | |
1041 | TAILQ_INIT(preferred); /* preferred order of keys */ | |
1042 | ||
1043 | /* list of keys stored in the filesystem */ | |
1044 | for (i = 0; i < options.num_identity_files; i++) { | |
1045 | key = options.identity_keys[i]; | |
1046 | if (key && key->type == KEY_RSA1) | |
1047 | continue; | |
1048 | options.identity_keys[i] = NULL; | |
9108f8d9 | 1049 | id = xcalloc(1, sizeof(*id)); |
0fff78ff | 1050 | id->key = key; |
1051 | id->filename = xstrdup(options.identity_files[i]); | |
1052 | TAILQ_INSERT_TAIL(&files, id, next); | |
1053 | } | |
1054 | /* list of keys supported by the agent */ | |
1055 | if ((ac = ssh_get_authentication_connection())) { | |
1056 | for (key = ssh_get_first_identity(ac, &comment, 2); | |
1057 | key != NULL; | |
1058 | key = ssh_get_next_identity(ac, &comment, 2)) { | |
1059 | found = 0; | |
1060 | TAILQ_FOREACH(id, &files, next) { | |
cdd66111 | 1061 | /* agent keys from the config file are preferred */ |
0fff78ff | 1062 | if (key_equal(key, id->key)) { |
1063 | key_free(key); | |
1064 | xfree(comment); | |
1065 | TAILQ_REMOVE(&files, id, next); | |
1066 | TAILQ_INSERT_TAIL(preferred, id, next); | |
1067 | id->ac = ac; | |
1068 | found = 1; | |
1069 | break; | |
1070 | } | |
1071 | } | |
99be0775 | 1072 | if (!found && !options.identities_only) { |
9108f8d9 | 1073 | id = xcalloc(1, sizeof(*id)); |
0fff78ff | 1074 | id->key = key; |
1075 | id->filename = comment; | |
1076 | id->ac = ac; | |
1077 | TAILQ_INSERT_TAIL(&agent, id, next); | |
1078 | } | |
1079 | } | |
1080 | /* append remaining agent keys */ | |
1081 | for (id = TAILQ_FIRST(&agent); id; id = TAILQ_FIRST(&agent)) { | |
1082 | TAILQ_REMOVE(&agent, id, next); | |
1083 | TAILQ_INSERT_TAIL(preferred, id, next); | |
1084 | } | |
1085 | authctxt->agent = ac; | |
1086 | } | |
1087 | /* append remaining keys from the config file */ | |
1088 | for (id = TAILQ_FIRST(&files); id; id = TAILQ_FIRST(&files)) { | |
1089 | TAILQ_REMOVE(&files, id, next); | |
1090 | TAILQ_INSERT_TAIL(preferred, id, next); | |
1091 | } | |
1092 | TAILQ_FOREACH(id, preferred, next) { | |
1093 | debug2("key: %s (%p)", id->filename, id->key); | |
1094 | } | |
3c0ef626 | 1095 | } |
1096 | ||
0fff78ff | 1097 | static void |
1098 | pubkey_cleanup(Authctxt *authctxt) | |
3c0ef626 | 1099 | { |
0fff78ff | 1100 | Identity *id; |
1101 | ||
1102 | if (authctxt->agent != NULL) | |
1103 | ssh_close_authentication_connection(authctxt->agent); | |
1104 | for (id = TAILQ_FIRST(&authctxt->keys); id; | |
1105 | id = TAILQ_FIRST(&authctxt->keys)) { | |
1106 | TAILQ_REMOVE(&authctxt->keys, id, next); | |
1107 | if (id->key) | |
1108 | key_free(id->key); | |
1109 | if (id->filename) | |
1110 | xfree(id->filename); | |
1111 | xfree(id); | |
3c0ef626 | 1112 | } |
3c0ef626 | 1113 | } |
1114 | ||
1115 | int | |
1116 | userauth_pubkey(Authctxt *authctxt) | |
1117 | { | |
0fff78ff | 1118 | Identity *id; |
3c0ef626 | 1119 | int sent = 0; |
0fff78ff | 1120 | |
1121 | while ((id = TAILQ_FIRST(&authctxt->keys))) { | |
1122 | if (id->tried++) | |
1123 | return (0); | |
cdd66111 | 1124 | /* move key to the end of the queue */ |
0fff78ff | 1125 | TAILQ_REMOVE(&authctxt->keys, id, next); |
1126 | TAILQ_INSERT_TAIL(&authctxt->keys, id, next); | |
1127 | /* | |
1128 | * send a test message if we have the public key. for | |
1129 | * encrypted keys we cannot do this and have to load the | |
1130 | * private key instead | |
1131 | */ | |
1132 | if (id->key && id->key->type != KEY_RSA1) { | |
1133 | debug("Offering public key: %s", id->filename); | |
1134 | sent = send_pubkey_test(authctxt, id); | |
1135 | } else if (id->key == NULL) { | |
1136 | debug("Trying private key: %s", id->filename); | |
1137 | id->key = load_identity_file(id->filename); | |
1138 | if (id->key != NULL) { | |
1139 | id->isprivate = 1; | |
1140 | sent = sign_and_send_pubkey(authctxt, id); | |
1141 | key_free(id->key); | |
1142 | id->key = NULL; | |
3c0ef626 | 1143 | } |
3c0ef626 | 1144 | } |
0fff78ff | 1145 | if (sent) |
1146 | return (sent); | |
3c0ef626 | 1147 | } |
0fff78ff | 1148 | return (0); |
3c0ef626 | 1149 | } |
1150 | ||
1151 | /* | |
1152 | * Send userauth request message specifying keyboard-interactive method. | |
1153 | */ | |
1154 | int | |
1155 | userauth_kbdint(Authctxt *authctxt) | |
1156 | { | |
1157 | static int attempt = 0; | |
1158 | ||
1159 | if (attempt++ >= options.number_of_password_prompts) | |
1160 | return 0; | |
1161 | /* disable if no SSH2_MSG_USERAUTH_INFO_REQUEST has been seen */ | |
1162 | if (attempt > 1 && !authctxt->info_req_seen) { | |
1163 | debug3("userauth_kbdint: disable: no info_req_seen"); | |
1164 | dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, NULL); | |
1165 | return 0; | |
1166 | } | |
1167 | ||
1168 | debug2("userauth_kbdint"); | |
1169 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
1170 | packet_put_cstring(authctxt->server_user); | |
1171 | packet_put_cstring(authctxt->service); | |
1172 | packet_put_cstring(authctxt->method->name); | |
1173 | packet_put_cstring(""); /* lang */ | |
1174 | packet_put_cstring(options.kbd_interactive_devices ? | |
1175 | options.kbd_interactive_devices : ""); | |
1176 | packet_send(); | |
1177 | ||
1178 | dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, &input_userauth_info_req); | |
1179 | return 1; | |
1180 | } | |
1181 | ||
1182 | /* | |
1183 | * parse INFO_REQUEST, prompt user and send INFO_RESPONSE | |
1184 | */ | |
1185 | void | |
e9a17296 | 1186 | input_userauth_info_req(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 1187 | { |
1188 | Authctxt *authctxt = ctxt; | |
1189 | char *name, *inst, *lang, *prompt, *response; | |
1190 | u_int num_prompts, i; | |
1191 | int echo = 0; | |
1192 | ||
1193 | debug2("input_userauth_info_req"); | |
1194 | ||
1195 | if (authctxt == NULL) | |
1196 | fatal("input_userauth_info_req: no authentication context"); | |
1197 | ||
1198 | authctxt->info_req_seen = 1; | |
1199 | ||
1200 | name = packet_get_string(NULL); | |
1201 | inst = packet_get_string(NULL); | |
1202 | lang = packet_get_string(NULL); | |
1203 | if (strlen(name) > 0) | |
0fff78ff | 1204 | logit("%s", name); |
3c0ef626 | 1205 | if (strlen(inst) > 0) |
0fff78ff | 1206 | logit("%s", inst); |
3c0ef626 | 1207 | xfree(name); |
1208 | xfree(inst); | |
1209 | xfree(lang); | |
1210 | ||
1211 | num_prompts = packet_get_int(); | |
1212 | /* | |
1213 | * Begin to build info response packet based on prompts requested. | |
1214 | * We commit to providing the correct number of responses, so if | |
1215 | * further on we run into a problem that prevents this, we have to | |
1216 | * be sure and clean this up and send a correct error response. | |
1217 | */ | |
1218 | packet_start(SSH2_MSG_USERAUTH_INFO_RESPONSE); | |
1219 | packet_put_int(num_prompts); | |
1220 | ||
1221 | debug2("input_userauth_info_req: num_prompts %d", num_prompts); | |
1222 | for (i = 0; i < num_prompts; i++) { | |
1223 | prompt = packet_get_string(NULL); | |
1224 | echo = packet_get_char(); | |
1225 | ||
1226 | response = read_passphrase(prompt, echo ? RP_ECHO : 0); | |
1227 | ||
1228 | packet_put_cstring(response); | |
1229 | memset(response, 0, strlen(response)); | |
1230 | xfree(response); | |
1231 | xfree(prompt); | |
1232 | } | |
e9a17296 | 1233 | packet_check_eom(); /* done with parsing incoming message. */ |
3c0ef626 | 1234 | |
1235 | packet_add_padding(64); | |
1236 | packet_send(); | |
1237 | } | |
1238 | ||
f5799ae1 | 1239 | static int |
680cee3b | 1240 | ssh_keysign(Key *key, u_char **sigp, u_int *lenp, |
f5799ae1 | 1241 | u_char *data, u_int datalen) |
1242 | { | |
1243 | Buffer b; | |
1244 | struct stat st; | |
1245 | pid_t pid; | |
1246 | int to[2], from[2], status, version = 2; | |
1247 | ||
6a9b3198 | 1248 | debug2("ssh_keysign called"); |
f5799ae1 | 1249 | |
1250 | if (stat(_PATH_SSH_KEY_SIGN, &st) < 0) { | |
1251 | error("ssh_keysign: no installed: %s", strerror(errno)); | |
1252 | return -1; | |
1253 | } | |
1254 | if (fflush(stdout) != 0) | |
1255 | error("ssh_keysign: fflush: %s", strerror(errno)); | |
1256 | if (pipe(to) < 0) { | |
1257 | error("ssh_keysign: pipe: %s", strerror(errno)); | |
1258 | return -1; | |
1259 | } | |
1260 | if (pipe(from) < 0) { | |
1261 | error("ssh_keysign: pipe: %s", strerror(errno)); | |
1262 | return -1; | |
1263 | } | |
1264 | if ((pid = fork()) < 0) { | |
1265 | error("ssh_keysign: fork: %s", strerror(errno)); | |
1266 | return -1; | |
1267 | } | |
1268 | if (pid == 0) { | |
9108f8d9 | 1269 | permanently_drop_suid(getuid()); |
f5799ae1 | 1270 | close(from[0]); |
1271 | if (dup2(from[1], STDOUT_FILENO) < 0) | |
1272 | fatal("ssh_keysign: dup2: %s", strerror(errno)); | |
1273 | close(to[1]); | |
1274 | if (dup2(to[0], STDIN_FILENO) < 0) | |
1275 | fatal("ssh_keysign: dup2: %s", strerror(errno)); | |
1276 | close(from[1]); | |
1277 | close(to[0]); | |
1278 | execl(_PATH_SSH_KEY_SIGN, _PATH_SSH_KEY_SIGN, (char *) 0); | |
1279 | fatal("ssh_keysign: exec(%s): %s", _PATH_SSH_KEY_SIGN, | |
1280 | strerror(errno)); | |
1281 | } | |
1282 | close(from[1]); | |
1283 | close(to[0]); | |
1284 | ||
1285 | buffer_init(&b); | |
1286 | buffer_put_int(&b, packet_get_connection_in()); /* send # of socket */ | |
1287 | buffer_put_string(&b, data, datalen); | |
cdd66111 | 1288 | if (ssh_msg_send(to[1], version, &b) == -1) |
1289 | fatal("ssh_keysign: couldn't send request"); | |
f5799ae1 | 1290 | |
41b2f314 | 1291 | if (ssh_msg_recv(from[0], &b) < 0) { |
f5799ae1 | 1292 | error("ssh_keysign: no reply"); |
cdd66111 | 1293 | buffer_free(&b); |
f5799ae1 | 1294 | return -1; |
1295 | } | |
1296 | close(from[0]); | |
1297 | close(to[1]); | |
1298 | ||
1299 | while (waitpid(pid, &status, 0) < 0) | |
1300 | if (errno != EINTR) | |
1301 | break; | |
1302 | ||
1303 | if (buffer_get_char(&b) != version) { | |
1304 | error("ssh_keysign: bad version"); | |
cdd66111 | 1305 | buffer_free(&b); |
f5799ae1 | 1306 | return -1; |
1307 | } | |
1308 | *sigp = buffer_get_string(&b, lenp); | |
cdd66111 | 1309 | buffer_free(&b); |
f5799ae1 | 1310 | |
1311 | return 0; | |
1312 | } | |
1313 | ||
3c0ef626 | 1314 | int |
1315 | userauth_hostbased(Authctxt *authctxt) | |
1316 | { | |
1317 | Key *private = NULL; | |
f5799ae1 | 1318 | Sensitive *sensitive = authctxt->sensitive; |
3c0ef626 | 1319 | Buffer b; |
1320 | u_char *signature, *blob; | |
d4487008 | 1321 | char *chost, *pkalg, *p, myname[NI_MAXHOST]; |
3c0ef626 | 1322 | const char *service; |
1323 | u_int blen, slen; | |
1324 | int ok, i, len, found = 0; | |
1325 | ||
1326 | /* check for a useful key */ | |
f5799ae1 | 1327 | for (i = 0; i < sensitive->nkeys; i++) { |
1328 | private = sensitive->keys[i]; | |
3c0ef626 | 1329 | if (private && private->type != KEY_RSA1) { |
1330 | found = 1; | |
1331 | /* we take and free the key */ | |
f5799ae1 | 1332 | sensitive->keys[i] = NULL; |
3c0ef626 | 1333 | break; |
1334 | } | |
1335 | } | |
1336 | if (!found) { | |
6a9b3198 | 1337 | debug("No more client hostkeys for hostbased authentication."); |
3c0ef626 | 1338 | return 0; |
1339 | } | |
1340 | if (key_to_blob(private, &blob, &blen) == 0) { | |
1341 | key_free(private); | |
1342 | return 0; | |
1343 | } | |
1344 | /* figure out a name for the client host */ | |
d4487008 | 1345 | p = NULL; |
1346 | if (packet_connection_is_on_socket()) | |
1347 | p = get_local_name(packet_get_connection_in()); | |
1348 | if (p == NULL) { | |
1349 | if (gethostname(myname, sizeof(myname)) == -1) { | |
1350 | verbose("userauth_hostbased: gethostname: %s", | |
1351 | strerror(errno)); | |
1352 | } else | |
1353 | p = xstrdup(myname); | |
1354 | } | |
3c0ef626 | 1355 | if (p == NULL) { |
1356 | error("userauth_hostbased: cannot get local ipaddr/name"); | |
1357 | key_free(private); | |
9108f8d9 | 1358 | xfree(blob); |
3c0ef626 | 1359 | return 0; |
1360 | } | |
1361 | len = strlen(p) + 2; | |
9108f8d9 | 1362 | xasprintf(&chost, "%s.", p); |
3c0ef626 | 1363 | debug2("userauth_hostbased: chost %s", chost); |
6a9b3198 | 1364 | xfree(p); |
3c0ef626 | 1365 | |
1366 | service = datafellows & SSH_BUG_HBSERVICE ? "ssh-userauth" : | |
1367 | authctxt->service; | |
1368 | pkalg = xstrdup(key_ssh_name(private)); | |
1369 | buffer_init(&b); | |
1370 | /* construct data */ | |
1371 | buffer_put_string(&b, session_id2, session_id2_len); | |
1372 | buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST); | |
1373 | buffer_put_cstring(&b, authctxt->server_user); | |
1374 | buffer_put_cstring(&b, service); | |
1375 | buffer_put_cstring(&b, authctxt->method->name); | |
1376 | buffer_put_cstring(&b, pkalg); | |
1377 | buffer_put_string(&b, blob, blen); | |
1378 | buffer_put_cstring(&b, chost); | |
1379 | buffer_put_cstring(&b, authctxt->local_user); | |
1380 | #ifdef DEBUG_PK | |
1381 | buffer_dump(&b); | |
1382 | #endif | |
f5799ae1 | 1383 | if (sensitive->external_keysign) |
1384 | ok = ssh_keysign(private, &signature, &slen, | |
1385 | buffer_ptr(&b), buffer_len(&b)); | |
1386 | else | |
1387 | ok = key_sign(private, &signature, &slen, | |
1388 | buffer_ptr(&b), buffer_len(&b)); | |
3c0ef626 | 1389 | key_free(private); |
1390 | buffer_free(&b); | |
1391 | if (ok != 0) { | |
1392 | error("key_sign failed"); | |
1393 | xfree(chost); | |
1394 | xfree(pkalg); | |
9108f8d9 | 1395 | xfree(blob); |
3c0ef626 | 1396 | return 0; |
1397 | } | |
1398 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
1399 | packet_put_cstring(authctxt->server_user); | |
1400 | packet_put_cstring(authctxt->service); | |
1401 | packet_put_cstring(authctxt->method->name); | |
1402 | packet_put_cstring(pkalg); | |
1403 | packet_put_string(blob, blen); | |
1404 | packet_put_cstring(chost); | |
1405 | packet_put_cstring(authctxt->local_user); | |
1406 | packet_put_string(signature, slen); | |
1407 | memset(signature, 's', slen); | |
1408 | xfree(signature); | |
1409 | xfree(chost); | |
1410 | xfree(pkalg); | |
9108f8d9 | 1411 | xfree(blob); |
3c0ef626 | 1412 | |
1413 | packet_send(); | |
1414 | return 1; | |
1415 | } | |
1416 | ||
1417 | /* find auth method */ | |
1418 | ||
1419 | /* | |
1420 | * given auth method name, if configurable options permit this method fill | |
1421 | * in auth_ident field and return true, otherwise return false. | |
1422 | */ | |
1423 | static int | |
1424 | authmethod_is_enabled(Authmethod *method) | |
1425 | { | |
1426 | if (method == NULL) | |
1427 | return 0; | |
1428 | /* return false if options indicate this method is disabled */ | |
1429 | if (method->enabled == NULL || *method->enabled == 0) | |
1430 | return 0; | |
1431 | /* return false if batch mode is enabled but method needs interactive mode */ | |
1432 | if (method->batch_flag != NULL && *method->batch_flag != 0) | |
1433 | return 0; | |
1434 | return 1; | |
1435 | } | |
1436 | ||
1437 | static Authmethod * | |
1438 | authmethod_lookup(const char *name) | |
1439 | { | |
1440 | Authmethod *method = NULL; | |
1441 | if (name != NULL) | |
1442 | for (method = authmethods; method->name != NULL; method++) | |
1443 | if (strcmp(name, method->name) == 0) | |
1444 | return method; | |
1445 | debug2("Unrecognized authentication method name: %s", name ? name : "NULL"); | |
1446 | return NULL; | |
1447 | } | |
1448 | ||
1449 | /* XXX internal state */ | |
1450 | static Authmethod *current = NULL; | |
1451 | static char *supported = NULL; | |
1452 | static char *preferred = NULL; | |
680cee3b | 1453 | |
3c0ef626 | 1454 | /* |
1455 | * Given the authentication method list sent by the server, return the | |
1456 | * next method we should try. If the server initially sends a nil list, | |
1457 | * use a built-in default list. | |
1458 | */ | |
1459 | static Authmethod * | |
1460 | authmethod_get(char *authlist) | |
1461 | { | |
3c0ef626 | 1462 | char *name = NULL; |
e9a17296 | 1463 | u_int next; |
3c0ef626 | 1464 | |
1465 | /* Use a suitable default if we're passed a nil list. */ | |
1466 | if (authlist == NULL || strlen(authlist) == 0) | |
1467 | authlist = options.preferred_authentications; | |
1468 | ||
1469 | if (supported == NULL || strcmp(authlist, supported) != 0) { | |
1470 | debug3("start over, passed a different list %s", authlist); | |
1471 | if (supported != NULL) | |
1472 | xfree(supported); | |
1473 | supported = xstrdup(authlist); | |
1474 | preferred = options.preferred_authentications; | |
1475 | debug3("preferred %s", preferred); | |
1476 | current = NULL; | |
1477 | } else if (current != NULL && authmethod_is_enabled(current)) | |
1478 | return current; | |
1479 | ||
1480 | for (;;) { | |
1481 | if ((name = match_list(preferred, supported, &next)) == NULL) { | |
6a9b3198 | 1482 | debug("No more authentication methods to try."); |
3c0ef626 | 1483 | current = NULL; |
1484 | return NULL; | |
1485 | } | |
1486 | preferred += next; | |
1487 | debug3("authmethod_lookup %s", name); | |
1488 | debug3("remaining preferred: %s", preferred); | |
1489 | if ((current = authmethod_lookup(name)) != NULL && | |
1490 | authmethod_is_enabled(current)) { | |
1491 | debug3("authmethod_is_enabled %s", name); | |
6a9b3198 | 1492 | debug("Next authentication method: %s", name); |
3c0ef626 | 1493 | return current; |
1494 | } | |
1495 | } | |
1496 | } | |
1497 | ||
3c0ef626 | 1498 | static char * |
1499 | authmethods_get(void) | |
1500 | { | |
1501 | Authmethod *method = NULL; | |
e9a17296 | 1502 | Buffer b; |
1503 | char *list; | |
3c0ef626 | 1504 | |
e9a17296 | 1505 | buffer_init(&b); |
3c0ef626 | 1506 | for (method = authmethods; method->name != NULL; method++) { |
1507 | if (authmethod_is_enabled(method)) { | |
e9a17296 | 1508 | if (buffer_len(&b) > 0) |
1509 | buffer_append(&b, ",", 1); | |
1510 | buffer_append(&b, method->name, strlen(method->name)); | |
3c0ef626 | 1511 | } |
1512 | } | |
e9a17296 | 1513 | buffer_append(&b, "\0", 1); |
1514 | list = xstrdup(buffer_ptr(&b)); | |
1515 | buffer_free(&b); | |
1516 | return list; | |
3c0ef626 | 1517 | } |