]>
Commit | Line | Data |
---|---|---|
a306f2dd | 1 | /* |
2 | * Copyright (c) 2000 Markus Friedl. All rights reserved. | |
3 | * | |
4 | * Redistribution and use in source and binary forms, with or without | |
5 | * modification, are permitted provided that the following conditions | |
6 | * are met: | |
7 | * 1. Redistributions of source code must retain the above copyright | |
8 | * notice, this list of conditions and the following disclaimer. | |
9 | * 2. Redistributions in binary form must reproduce the above copyright | |
10 | * notice, this list of conditions and the following disclaimer in the | |
11 | * documentation and/or other materials provided with the distribution. | |
a306f2dd | 12 | * |
13 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR | |
14 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES | |
15 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. | |
16 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, | |
17 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT | |
18 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, | |
19 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY | |
20 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT | |
21 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF | |
22 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | |
23 | */ | |
bcbf86ec | 24 | |
a306f2dd | 25 | #include "includes.h" |
bb5639fe | 26 | RCSID("$OpenBSD: auth2.c,v 1.48 2001/03/21 11:43:44 markus Exp $"); |
94ec8c6b | 27 | |
a306f2dd | 28 | #include <openssl/evp.h> |
29 | ||
42f11eb2 | 30 | #include "ssh2.h" |
a306f2dd | 31 | #include "xmalloc.h" |
32 | #include "rsa.h" | |
1729c161 | 33 | #include "sshpty.h" |
a306f2dd | 34 | #include "packet.h" |
35 | #include "buffer.h" | |
42f11eb2 | 36 | #include "log.h" |
a306f2dd | 37 | #include "servconf.h" |
38 | #include "compat.h" | |
39 | #include "channels.h" | |
40 | #include "bufaux.h" | |
a306f2dd | 41 | #include "auth.h" |
42 | #include "session.h" | |
43 | #include "dispatch.h" | |
a306f2dd | 44 | #include "key.h" |
b0e305c9 | 45 | #include "cipher.h" |
a306f2dd | 46 | #include "kex.h" |
42f11eb2 | 47 | #include "pathnames.h" |
a306f2dd | 48 | #include "uidswap.h" |
38c295d6 | 49 | #include "auth-options.h" |
3b1a83df | 50 | #include "misc.h" |
a306f2dd | 51 | |
52 | /* import */ | |
53 | extern ServerOptions options; | |
1e3b8b07 | 54 | extern u_char *session_id2; |
a306f2dd | 55 | extern int session_id2_len; |
56 | ||
94ec8c6b | 57 | #ifdef WITH_AIXAUTHENTICATE |
58 | extern char *aixloginmsg; | |
59 | #endif | |
94ec8c6b | 60 | |
61 | static Authctxt *x_authctxt = NULL; | |
62 | static int one = 1; | |
63 | ||
64 | typedef struct Authmethod Authmethod; | |
65 | struct Authmethod { | |
66 | char *name; | |
67 | int (*userauth)(Authctxt *authctxt); | |
68 | int *enabled; | |
69 | }; | |
70 | ||
a306f2dd | 71 | /* protocol */ |
72 | ||
188adeb2 | 73 | void input_service_request(int type, int plen, void *ctxt); |
74 | void input_userauth_request(int type, int plen, void *ctxt); | |
75 | void protocol_error(int type, int plen, void *ctxt); | |
a306f2dd | 76 | |
a306f2dd | 77 | /* helper */ |
94ec8c6b | 78 | Authmethod *authmethod_lookup(const char *name); |
fa08c86b | 79 | int user_key_allowed(struct passwd *pw, Key *key); |
94ec8c6b | 80 | char *authmethods_get(void); |
a306f2dd | 81 | |
94ec8c6b | 82 | /* auth */ |
eea39c02 | 83 | void userauth_banner(void); |
94ec8c6b | 84 | int userauth_none(Authctxt *authctxt); |
85 | int userauth_passwd(Authctxt *authctxt); | |
86 | int userauth_pubkey(Authctxt *authctxt); | |
87 | int userauth_kbdint(Authctxt *authctxt); | |
88 | ||
89 | Authmethod authmethods[] = { | |
90 | {"none", | |
91 | userauth_none, | |
92 | &one}, | |
93 | {"publickey", | |
94 | userauth_pubkey, | |
fa08c86b | 95 | &options.pubkey_authentication}, |
94ec8c6b | 96 | {"password", |
97 | userauth_passwd, | |
98 | &options.password_authentication}, | |
c845316f | 99 | {"keyboard-interactive", |
100 | userauth_kbdint, | |
101 | &options.kbd_interactive_authentication}, | |
94ec8c6b | 102 | {NULL, NULL, NULL} |
a306f2dd | 103 | }; |
a306f2dd | 104 | |
105 | /* | |
94ec8c6b | 106 | * loop until authctxt->success == TRUE |
a306f2dd | 107 | */ |
108 | ||
109 | void | |
110 | do_authentication2() | |
111 | { | |
59c97189 | 112 | Authctxt *authctxt = authctxt_new(); |
113 | ||
94ec8c6b | 114 | x_authctxt = authctxt; /*XXX*/ |
115 | ||
d464095c | 116 | /* challenge-reponse is implemented via keyboard interactive */ |
117 | if (options.challenge_reponse_authentication) | |
118 | options.kbd_interactive_authentication = 1; | |
119 | ||
a306f2dd | 120 | dispatch_init(&protocol_error); |
121 | dispatch_set(SSH2_MSG_SERVICE_REQUEST, &input_service_request); | |
94ec8c6b | 122 | dispatch_run(DISPATCH_BLOCK, &authctxt->success, authctxt); |
bb5639fe | 123 | do_authenticated(authctxt); |
a306f2dd | 124 | } |
125 | ||
126 | void | |
188adeb2 | 127 | protocol_error(int type, int plen, void *ctxt) |
a306f2dd | 128 | { |
129 | log("auth: protocol error: type %d plen %d", type, plen); | |
130 | packet_start(SSH2_MSG_UNIMPLEMENTED); | |
131 | packet_put_int(0); | |
132 | packet_send(); | |
133 | packet_write_wait(); | |
134 | } | |
135 | ||
136 | void | |
188adeb2 | 137 | input_service_request(int type, int plen, void *ctxt) |
a306f2dd | 138 | { |
94ec8c6b | 139 | Authctxt *authctxt = ctxt; |
1e3b8b07 | 140 | u_int len; |
a306f2dd | 141 | int accept = 0; |
142 | char *service = packet_get_string(&len); | |
143 | packet_done(); | |
144 | ||
94ec8c6b | 145 | if (authctxt == NULL) |
146 | fatal("input_service_request: no authctxt"); | |
147 | ||
a306f2dd | 148 | if (strcmp(service, "ssh-userauth") == 0) { |
94ec8c6b | 149 | if (!authctxt->success) { |
a306f2dd | 150 | accept = 1; |
151 | /* now we can handle user-auth requests */ | |
152 | dispatch_set(SSH2_MSG_USERAUTH_REQUEST, &input_userauth_request); | |
153 | } | |
154 | } | |
155 | /* XXX all other service requests are denied */ | |
156 | ||
157 | if (accept) { | |
158 | packet_start(SSH2_MSG_SERVICE_ACCEPT); | |
159 | packet_put_cstring(service); | |
160 | packet_send(); | |
161 | packet_write_wait(); | |
162 | } else { | |
163 | debug("bad service request %s", service); | |
164 | packet_disconnect("bad service request %s", service); | |
165 | } | |
166 | xfree(service); | |
167 | } | |
168 | ||
169 | void | |
188adeb2 | 170 | input_userauth_request(int type, int plen, void *ctxt) |
a306f2dd | 171 | { |
94ec8c6b | 172 | Authctxt *authctxt = ctxt; |
173 | Authmethod *m = NULL; | |
59c97189 | 174 | char *user, *service, *method, *style = NULL; |
a306f2dd | 175 | int authenticated = 0; |
a306f2dd | 176 | |
94ec8c6b | 177 | if (authctxt == NULL) |
178 | fatal("input_userauth_request: no authctxt"); | |
a306f2dd | 179 | |
94ec8c6b | 180 | user = packet_get_string(NULL); |
181 | service = packet_get_string(NULL); | |
182 | method = packet_get_string(NULL); | |
183 | debug("userauth-request for user %s service %s method %s", user, service, method); | |
8abcdba4 | 184 | debug("attempt %d failures %d", authctxt->attempt, authctxt->failures); |
94ec8c6b | 185 | |
59c97189 | 186 | if ((style = strchr(user, ':')) != NULL) |
187 | *style++ = 0; | |
188 | ||
2b87da3b | 189 | if (authctxt->attempt++ == 0) { |
94ec8c6b | 190 | /* setup auth context */ |
191 | struct passwd *pw = NULL; | |
94ec8c6b | 192 | pw = getpwnam(user); |
193 | if (pw && allowed_user(pw) && strcmp(service, "ssh-connection")==0) { | |
194 | authctxt->pw = pwcopy(pw); | |
195 | authctxt->valid = 1; | |
196 | debug2("input_userauth_request: setting up authctxt for %s", user); | |
197 | #ifdef USE_PAM | |
04fc7a67 | 198 | start_pam(pw->pw_name); |
94ec8c6b | 199 | #endif |
200 | } else { | |
201 | log("input_userauth_request: illegal user %s", user); | |
04fc7a67 | 202 | #ifdef USE_PAM |
203 | start_pam("NOUSER"); | |
204 | #endif | |
94ec8c6b | 205 | } |
6172e290 | 206 | setproctitle("%s", pw ? user : "unknown"); |
94ec8c6b | 207 | authctxt->user = xstrdup(user); |
208 | authctxt->service = xstrdup(service); | |
59c97189 | 209 | authctxt->style = style ? xstrdup(style) : NULL; /* currently unused */ |
94ec8c6b | 210 | } else if (authctxt->valid) { |
211 | if (strcmp(user, authctxt->user) != 0 || | |
212 | strcmp(service, authctxt->service) != 0) { | |
213 | log("input_userauth_request: missmatch: (%s,%s)!=(%s,%s)", | |
214 | user, service, authctxt->user, authctxt->service); | |
215 | authctxt->valid = 0; | |
a306f2dd | 216 | } |
217 | } | |
59c97189 | 218 | /* reset state */ |
219 | dispatch_set(SSH2_MSG_USERAUTH_INFO_RESPONSE, &protocol_error); | |
220 | authctxt->postponed = 0; | |
af774732 | 221 | #ifdef BSD_AUTH |
222 | if (authctxt->as) { | |
223 | auth_close(authctxt->as); | |
224 | authctxt->as = NULL; | |
225 | } | |
226 | #endif | |
9cd45ea4 | 227 | |
59c97189 | 228 | /* try to authenticate user */ |
94ec8c6b | 229 | m = authmethod_lookup(method); |
230 | if (m != NULL) { | |
231 | debug2("input_userauth_request: try method %s", method); | |
232 | authenticated = m->userauth(authctxt); | |
9cd45ea4 | 233 | } |
59c97189 | 234 | if (!authctxt->valid && authenticated) |
235 | fatal("INTERNAL ERROR: authenticated invalid user %s", | |
236 | authctxt->user); | |
9cd45ea4 | 237 | |
94ec8c6b | 238 | /* Special handling for root */ |
15853e93 | 239 | if (authenticated && authctxt->pw->pw_uid == 0 && |
240 | !auth_root_allowed(method)) | |
a306f2dd | 241 | authenticated = 0; |
a306f2dd | 242 | |
243 | #ifdef USE_PAM | |
edef62bf | 244 | if (authenticated && authctxt->user && !do_pam_account(authctxt->user, |
245 | NULL)) | |
9cd45ea4 | 246 | authenticated = 0; |
a306f2dd | 247 | #endif /* USE_PAM */ |
248 | ||
94ec8c6b | 249 | /* Log before sending the reply */ |
59c97189 | 250 | auth_log(authctxt, authenticated, method, " ssh2"); |
251 | ||
252 | if (!authctxt->postponed) | |
253 | userauth_reply(authctxt, authenticated); | |
94ec8c6b | 254 | |
255 | xfree(service); | |
256 | xfree(user); | |
257 | xfree(method); | |
258 | } | |
259 | ||
eea39c02 | 260 | void |
261 | userauth_banner(void) | |
262 | { | |
263 | struct stat st; | |
264 | char *banner = NULL; | |
265 | off_t len, n; | |
266 | int fd; | |
267 | ||
268 | if (options.banner == NULL || (datafellows & SSH_BUG_BANNER)) | |
269 | return; | |
270 | if ((fd = open(options.banner, O_RDONLY)) < 0) { | |
271 | error("userauth_banner: open %s failed: %s", | |
272 | options.banner, strerror(errno)); | |
273 | return; | |
274 | } | |
275 | if (fstat(fd, &st) < 0) | |
276 | goto done; | |
277 | len = st.st_size; | |
278 | banner = xmalloc(len + 1); | |
279 | if ((n = read(fd, banner, len)) < 0) | |
280 | goto done; | |
281 | banner[n] = '\0'; | |
282 | packet_start(SSH2_MSG_USERAUTH_BANNER); | |
283 | packet_put_cstring(banner); | |
284 | packet_put_cstring(""); /* language, unused */ | |
285 | packet_send(); | |
286 | debug("userauth_banner: sent"); | |
287 | done: | |
288 | if (banner) | |
289 | xfree(banner); | |
290 | close(fd); | |
291 | return; | |
292 | } | |
94ec8c6b | 293 | |
2b87da3b | 294 | void |
94ec8c6b | 295 | userauth_reply(Authctxt *authctxt, int authenticated) |
296 | { | |
8abcdba4 | 297 | char *methods; |
59c97189 | 298 | |
1d1ffb87 | 299 | /* XXX todo: check if multiple auth methods are needed */ |
25f4c264 | 300 | if (authenticated == 1) { |
c1ef8333 | 301 | #ifdef WITH_AIXAUTHENTICATE |
302 | /* We don't have a pty yet, so just label the line as "ssh" */ | |
2b87da3b | 303 | if (loginsuccess(authctxt->user?authctxt->user:"NOUSER", |
304 | get_canonical_hostname(options.reverse_mapping_check), | |
61e96248 | 305 | "ssh", &aixloginmsg) < 0) |
c1ef8333 | 306 | aixloginmsg = NULL; |
307 | #endif /* WITH_AIXAUTHENTICATE */ | |
a306f2dd | 308 | /* turn off userauth */ |
309 | dispatch_set(SSH2_MSG_USERAUTH_REQUEST, &protocol_error); | |
310 | packet_start(SSH2_MSG_USERAUTH_SUCCESS); | |
311 | packet_send(); | |
312 | packet_write_wait(); | |
313 | /* now we can break out */ | |
94ec8c6b | 314 | authctxt->success = 1; |
59c97189 | 315 | } else { |
316 | if (authctxt->failures++ > AUTH_FAIL_MAX) | |
2b87da3b | 317 | packet_disconnect(AUTH_FAIL_MSG, authctxt->user); |
8abcdba4 | 318 | methods = authmethods_get(); |
a306f2dd | 319 | packet_start(SSH2_MSG_USERAUTH_FAILURE); |
94ec8c6b | 320 | packet_put_cstring(methods); |
321 | packet_put_char(0); /* XXX partial success, unused */ | |
a306f2dd | 322 | packet_send(); |
323 | packet_write_wait(); | |
94ec8c6b | 324 | xfree(methods); |
a306f2dd | 325 | } |
a306f2dd | 326 | } |
327 | ||
328 | int | |
94ec8c6b | 329 | userauth_none(Authctxt *authctxt) |
a306f2dd | 330 | { |
94ec8c6b | 331 | /* disable method "none", only allowed one time */ |
332 | Authmethod *m = authmethod_lookup("none"); | |
333 | if (m != NULL) | |
334 | m->enabled = NULL; | |
a306f2dd | 335 | packet_done(); |
2b87da3b | 336 | userauth_banner(); |
4d33e531 | 337 | |
94ec8c6b | 338 | if (authctxt->valid == 0) |
339 | return(0); | |
2b87da3b | 340 | |
94ec8c6b | 341 | #ifdef HAVE_CYGWIN |
342 | if (check_nt_auth(1, authctxt->pw->pw_uid) == 0) | |
343 | return(0); | |
344 | #endif | |
a306f2dd | 345 | #ifdef USE_PAM |
94ec8c6b | 346 | return auth_pam_password(authctxt->pw, ""); |
4d33e531 | 347 | #elif defined(HAVE_OSF_SIA) |
b7ccb051 | 348 | return 0; |
4d33e531 | 349 | #else /* !HAVE_OSF_SIA && !USE_PAM */ |
af774732 | 350 | return auth_password(authctxt, ""); |
a306f2dd | 351 | #endif /* USE_PAM */ |
352 | } | |
94ec8c6b | 353 | |
a306f2dd | 354 | int |
94ec8c6b | 355 | userauth_passwd(Authctxt *authctxt) |
a306f2dd | 356 | { |
357 | char *password; | |
358 | int authenticated = 0; | |
359 | int change; | |
1e3b8b07 | 360 | u_int len; |
a306f2dd | 361 | change = packet_get_char(); |
362 | if (change) | |
363 | log("password change not supported"); | |
364 | password = packet_get_string(&len); | |
365 | packet_done(); | |
94ec8c6b | 366 | if (authctxt->valid && |
367 | #ifdef HAVE_CYGWIN | |
368 | check_nt_auth(1, authctxt->pw->pw_uid) && | |
369 | #endif | |
a306f2dd | 370 | #ifdef USE_PAM |
94ec8c6b | 371 | auth_pam_password(authctxt->pw, password) == 1) |
4d33e531 | 372 | #elif defined(HAVE_OSF_SIA) |
b7ccb051 | 373 | auth_sia_password(authctxt->user, password) == 1) |
4d33e531 | 374 | #else /* !USE_PAM && !HAVE_OSF_SIA */ |
af774732 | 375 | auth_password(authctxt, password) == 1) |
a306f2dd | 376 | #endif /* USE_PAM */ |
377 | authenticated = 1; | |
378 | memset(password, 0, len); | |
379 | xfree(password); | |
380 | return authenticated; | |
381 | } | |
94ec8c6b | 382 | |
383 | int | |
384 | userauth_kbdint(Authctxt *authctxt) | |
385 | { | |
386 | int authenticated = 0; | |
387 | char *lang = NULL; | |
388 | char *devs = NULL; | |
389 | ||
390 | lang = packet_get_string(NULL); | |
391 | devs = packet_get_string(NULL); | |
392 | packet_done(); | |
393 | ||
394 | debug("keyboard-interactive language %s devs %s", lang, devs); | |
59c97189 | 395 | |
d464095c | 396 | if (options.challenge_reponse_authentication) |
397 | authenticated = auth2_challenge(authctxt, devs); | |
59c97189 | 398 | |
8c9fe09e | 399 | #ifdef USE_PAM |
400 | if (authenticated == 0) | |
401 | authenticated = auth2_pam(authctxt); | |
94ec8c6b | 402 | #endif |
403 | xfree(lang); | |
404 | xfree(devs); | |
405 | #ifdef HAVE_CYGWIN | |
406 | if (check_nt_auth(0, authctxt->pw->pw_uid) == 0) | |
407 | return(0); | |
408 | #endif | |
409 | return authenticated; | |
410 | } | |
411 | ||
a306f2dd | 412 | int |
94ec8c6b | 413 | userauth_pubkey(Authctxt *authctxt) |
a306f2dd | 414 | { |
415 | Buffer b; | |
416 | Key *key; | |
417 | char *pkalg, *pkblob, *sig; | |
1e3b8b07 | 418 | u_int alen, blen, slen; |
fa08c86b | 419 | int have_sig, pktype; |
a306f2dd | 420 | int authenticated = 0; |
421 | ||
94ec8c6b | 422 | if (!authctxt->valid) { |
423 | debug2("userauth_pubkey: disabled because of invalid user"); | |
a306f2dd | 424 | return 0; |
425 | } | |
426 | have_sig = packet_get_char(); | |
cbc5abf9 | 427 | if (datafellows & SSH_BUG_PKAUTH) { |
428 | debug2("userauth_pubkey: SSH_BUG_PKAUTH"); | |
429 | /* no explicit pkalg given */ | |
430 | pkblob = packet_get_string(&blen); | |
431 | buffer_init(&b); | |
432 | buffer_append(&b, pkblob, blen); | |
433 | /* so we have to extract the pkalg from the pkblob */ | |
434 | pkalg = buffer_get_string(&b, &alen); | |
435 | buffer_free(&b); | |
436 | } else { | |
437 | pkalg = packet_get_string(&alen); | |
438 | pkblob = packet_get_string(&blen); | |
439 | } | |
fa08c86b | 440 | pktype = key_type_from_name(pkalg); |
441 | if (pktype == KEY_UNSPEC) { | |
cbc5abf9 | 442 | /* this is perfectly legal */ |
443 | log("userauth_pubkey: unsupported public key algorithm: %s", pkalg); | |
94ec8c6b | 444 | xfree(pkalg); |
cbc5abf9 | 445 | xfree(pkblob); |
a306f2dd | 446 | return 0; |
447 | } | |
fa08c86b | 448 | key = key_from_blob(pkblob, blen); |
a306f2dd | 449 | if (key != NULL) { |
450 | if (have_sig) { | |
451 | sig = packet_get_string(&slen); | |
452 | packet_done(); | |
453 | buffer_init(&b); | |
33de75a3 | 454 | if (datafellows & SSH_OLD_SESSIONID) { |
74fc9186 | 455 | buffer_append(&b, session_id2, session_id2_len); |
33de75a3 | 456 | } else { |
457 | buffer_put_string(&b, session_id2, session_id2_len); | |
74fc9186 | 458 | } |
38c295d6 | 459 | /* reconstruct packet */ |
a306f2dd | 460 | buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST); |
94ec8c6b | 461 | buffer_put_cstring(&b, authctxt->user); |
38c295d6 | 462 | buffer_put_cstring(&b, |
cbc5abf9 | 463 | datafellows & SSH_BUG_PKSERVICE ? |
38c295d6 | 464 | "ssh-userauth" : |
94ec8c6b | 465 | authctxt->service); |
cbc5abf9 | 466 | if (datafellows & SSH_BUG_PKAUTH) { |
467 | buffer_put_char(&b, have_sig); | |
468 | } else { | |
469 | buffer_put_cstring(&b, "publickey"); | |
470 | buffer_put_char(&b, have_sig); | |
471 | buffer_put_cstring(&b, key_ssh_name(key)); | |
472 | } | |
38c295d6 | 473 | buffer_put_string(&b, pkblob, blen); |
fa08c86b | 474 | #ifdef DEBUG_PK |
a306f2dd | 475 | buffer_dump(&b); |
476 | #endif | |
477 | /* test for correct signature */ | |
fa08c86b | 478 | if (user_key_allowed(authctxt->pw, key) && |
479 | key_verify(key, sig, slen, buffer_ptr(&b), buffer_len(&b)) == 1) | |
a306f2dd | 480 | authenticated = 1; |
481 | buffer_clear(&b); | |
482 | xfree(sig); | |
483 | } else { | |
94ec8c6b | 484 | debug("test whether pkalg/pkblob are acceptable"); |
a306f2dd | 485 | packet_done(); |
94ec8c6b | 486 | |
a306f2dd | 487 | /* XXX fake reply and always send PK_OK ? */ |
1d1ffb87 | 488 | /* |
489 | * XXX this allows testing whether a user is allowed | |
490 | * to login: if you happen to have a valid pubkey this | |
491 | * message is sent. the message is NEVER sent at all | |
492 | * if a user is not allowed to login. is this an | |
493 | * issue? -markus | |
494 | */ | |
fa08c86b | 495 | if (user_key_allowed(authctxt->pw, key)) { |
a306f2dd | 496 | packet_start(SSH2_MSG_USERAUTH_PK_OK); |
497 | packet_put_string(pkalg, alen); | |
498 | packet_put_string(pkblob, blen); | |
499 | packet_send(); | |
500 | packet_write_wait(); | |
25f4c264 | 501 | authctxt->postponed = 1; |
a306f2dd | 502 | } |
503 | } | |
94ec8c6b | 504 | if (authenticated != 1) |
505 | auth_clear_options(); | |
a306f2dd | 506 | key_free(key); |
507 | } | |
fa08c86b | 508 | debug2("userauth_pubkey: authenticated %d pkalg %s", authenticated, pkalg); |
a306f2dd | 509 | xfree(pkalg); |
510 | xfree(pkblob); | |
94ec8c6b | 511 | #ifdef HAVE_CYGWIN |
512 | if (check_nt_auth(0, authctxt->pw->pw_uid) == 0) | |
513 | return(0); | |
514 | #endif | |
a306f2dd | 515 | return authenticated; |
516 | } | |
517 | ||
94ec8c6b | 518 | /* get current user */ |
a306f2dd | 519 | |
520 | struct passwd* | |
521 | auth_get_user(void) | |
522 | { | |
94ec8c6b | 523 | return (x_authctxt != NULL && x_authctxt->valid) ? x_authctxt->pw : NULL; |
a306f2dd | 524 | } |
525 | ||
94ec8c6b | 526 | #define DELIM "," |
527 | ||
528 | char * | |
529 | authmethods_get(void) | |
a306f2dd | 530 | { |
94ec8c6b | 531 | Authmethod *method = NULL; |
1e3b8b07 | 532 | u_int size = 0; |
94ec8c6b | 533 | char *list; |
534 | ||
535 | for (method = authmethods; method->name != NULL; method++) { | |
536 | if (strcmp(method->name, "none") == 0) | |
537 | continue; | |
538 | if (method->enabled != NULL && *(method->enabled) != 0) { | |
539 | if (size != 0) | |
540 | size += strlen(DELIM); | |
541 | size += strlen(method->name); | |
a306f2dd | 542 | } |
94ec8c6b | 543 | } |
544 | size++; /* trailing '\0' */ | |
545 | list = xmalloc(size); | |
546 | list[0] = '\0'; | |
547 | ||
548 | for (method = authmethods; method->name != NULL; method++) { | |
549 | if (strcmp(method->name, "none") == 0) | |
550 | continue; | |
551 | if (method->enabled != NULL && *(method->enabled) != 0) { | |
552 | if (list[0] != '\0') | |
553 | strlcat(list, DELIM, size); | |
554 | strlcat(list, method->name, size); | |
a306f2dd | 555 | } |
556 | } | |
94ec8c6b | 557 | return list; |
558 | } | |
559 | ||
560 | Authmethod * | |
561 | authmethod_lookup(const char *name) | |
562 | { | |
563 | Authmethod *method = NULL; | |
564 | if (name != NULL) | |
565 | for (method = authmethods; method->name != NULL; method++) | |
566 | if (method->enabled != NULL && | |
567 | *(method->enabled) != 0 && | |
568 | strcmp(name, method->name) == 0) | |
569 | return method; | |
570 | debug2("Unrecognized authentication method name: %s", name ? name : "NULL"); | |
571 | return NULL; | |
a306f2dd | 572 | } |
573 | ||
574 | /* return 1 if user allows given key */ | |
575 | int | |
fa08c86b | 576 | user_key_allowed(struct passwd *pw, Key *key) |
a306f2dd | 577 | { |
42f11eb2 | 578 | char line[8192], file[MAXPATHLEN]; |
a306f2dd | 579 | int found_key = 0; |
a306f2dd | 580 | FILE *f; |
1e3b8b07 | 581 | u_long linenum = 0; |
a306f2dd | 582 | struct stat st; |
583 | Key *found; | |
584 | ||
94ec8c6b | 585 | if (pw == NULL) |
586 | return 0; | |
587 | ||
a306f2dd | 588 | /* Temporarily use the user's uid. */ |
589 | temporarily_use_uid(pw->pw_uid); | |
590 | ||
591 | /* The authorized keys. */ | |
592 | snprintf(file, sizeof file, "%.500s/%.100s", pw->pw_dir, | |
42f11eb2 | 593 | _PATH_SSH_USER_PERMITTED_KEYS2); |
a306f2dd | 594 | |
595 | /* Fail quietly if file does not exist */ | |
596 | if (stat(file, &st) < 0) { | |
597 | /* Restore the privileged uid. */ | |
598 | restore_uid(); | |
599 | return 0; | |
600 | } | |
601 | /* Open the file containing the authorized keys. */ | |
602 | f = fopen(file, "r"); | |
603 | if (!f) { | |
604 | /* Restore the privileged uid. */ | |
605 | restore_uid(); | |
606 | return 0; | |
607 | } | |
608 | if (options.strict_modes) { | |
609 | int fail = 0; | |
610 | char buf[1024]; | |
611 | /* Check open file in order to avoid open/stat races */ | |
612 | if (fstat(fileno(f), &st) < 0 || | |
613 | (st.st_uid != 0 && st.st_uid != pw->pw_uid) || | |
614 | (st.st_mode & 022) != 0) { | |
de273eef | 615 | snprintf(buf, sizeof buf, |
616 | "%s authentication refused for %.100s: " | |
617 | "bad ownership or modes for '%s'.", | |
618 | key_type(key), pw->pw_name, file); | |
a306f2dd | 619 | fail = 1; |
620 | } else { | |
42f11eb2 | 621 | /* Check path to _PATH_SSH_USER_PERMITTED_KEYS */ |
a306f2dd | 622 | int i; |
623 | static const char *check[] = { | |
42f11eb2 | 624 | "", _PATH_SSH_USER_DIR, NULL |
a306f2dd | 625 | }; |
626 | for (i = 0; check[i]; i++) { | |
627 | snprintf(line, sizeof line, "%.500s/%.100s", | |
628 | pw->pw_dir, check[i]); | |
629 | if (stat(line, &st) < 0 || | |
630 | (st.st_uid != 0 && st.st_uid != pw->pw_uid) || | |
631 | (st.st_mode & 022) != 0) { | |
632 | snprintf(buf, sizeof buf, | |
de273eef | 633 | "%s authentication refused for %.100s: " |
a306f2dd | 634 | "bad ownership or modes for '%s'.", |
de273eef | 635 | key_type(key), pw->pw_name, line); |
a306f2dd | 636 | fail = 1; |
637 | break; | |
638 | } | |
639 | } | |
640 | } | |
641 | if (fail) { | |
a306f2dd | 642 | fclose(f); |
12bf85ed | 643 | log("%s", buf); |
a306f2dd | 644 | restore_uid(); |
645 | return 0; | |
646 | } | |
647 | } | |
648 | found_key = 0; | |
de273eef | 649 | found = key_new(key->type); |
a306f2dd | 650 | |
651 | while (fgets(line, sizeof(line), f)) { | |
38c295d6 | 652 | char *cp, *options = NULL; |
a306f2dd | 653 | linenum++; |
654 | /* Skip leading whitespace, empty and comment lines. */ | |
655 | for (cp = line; *cp == ' ' || *cp == '\t'; cp++) | |
656 | ; | |
657 | if (!*cp || *cp == '\n' || *cp == '#') | |
658 | continue; | |
38c295d6 | 659 | |
fa08c86b | 660 | if (key_read(found, &cp) == -1) { |
38c295d6 | 661 | /* no key? check if there are options for this key */ |
662 | int quoted = 0; | |
fa08c86b | 663 | debug2("user_key_allowed: check options: '%s'", cp); |
38c295d6 | 664 | options = cp; |
665 | for (; *cp && (quoted || (*cp != ' ' && *cp != '\t')); cp++) { | |
666 | if (*cp == '\\' && cp[1] == '"') | |
667 | cp++; /* Skip both */ | |
668 | else if (*cp == '"') | |
669 | quoted = !quoted; | |
670 | } | |
671 | /* Skip remaining whitespace. */ | |
672 | for (; *cp == ' ' || *cp == '\t'; cp++) | |
673 | ; | |
fa08c86b | 674 | if (key_read(found, &cp) == -1) { |
675 | debug2("user_key_allowed: advance: '%s'", cp); | |
38c295d6 | 676 | /* still no key? advance to next line*/ |
677 | continue; | |
678 | } | |
679 | } | |
680 | if (key_equal(found, key) && | |
42f11eb2 | 681 | auth_parse_options(pw, options, file, linenum) == 1) { |
a306f2dd | 682 | found_key = 1; |
683 | debug("matching key found: file %s, line %ld", | |
684 | file, linenum); | |
685 | break; | |
686 | } | |
687 | } | |
688 | restore_uid(); | |
689 | fclose(f); | |
690 | key_free(found); | |
539af7f5 | 691 | if (!found_key) |
692 | debug2("key not found"); | |
a306f2dd | 693 | return found_key; |
694 | } |