blob: f34b586d4c5f1048a78d6ebe3ea3f0d732d5cf6e [file] [log] [blame]
Damien Millereba71ba2000-04-29 23:57:08 +10001/*
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.
Damien Millereba71ba2000-04-29 23:57:08 +100012 *
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 */
Damien Millere4340be2000-09-16 13:29:08 +110024
Damien Millereba71ba2000-04-29 23:57:08 +100025#include "includes.h"
Damien Miller874d77b2000-10-14 16:23:11 +110026RCSID("$OpenBSD: auth2.c,v 1.19 2000/10/11 20:27:23 markus Exp $");
27
28#ifdef HAVE_OSF_SIA
29# include <sia.h>
30# include <siad.h>
31#endif
Damien Millereba71ba2000-04-29 23:57:08 +100032
33#include <openssl/dsa.h>
34#include <openssl/rsa.h>
35#include <openssl/evp.h>
36
37#include "xmalloc.h"
38#include "rsa.h"
39#include "ssh.h"
40#include "pty.h"
41#include "packet.h"
42#include "buffer.h"
Damien Millereba71ba2000-04-29 23:57:08 +100043#include "servconf.h"
44#include "compat.h"
45#include "channels.h"
46#include "bufaux.h"
47#include "ssh2.h"
48#include "auth.h"
49#include "session.h"
50#include "dispatch.h"
51#include "auth.h"
52#include "key.h"
53#include "kex.h"
54
55#include "dsa.h"
56#include "uidswap.h"
Damien Millerf6d9e222000-06-18 14:50:44 +100057#include "auth-options.h"
Damien Millereba71ba2000-04-29 23:57:08 +100058
59/* import */
60extern ServerOptions options;
61extern unsigned char *session_id2;
62extern int session_id2_len;
63
Damien Miller874d77b2000-10-14 16:23:11 +110064#ifdef WITH_AIXAUTHENTICATE
65extern char *aixloginmsg;
66#endif
67#ifdef HAVE_OSF_SIA
68extern int saved_argc;
69extern char **saved_argv;
70#endif
71
72static Authctxt *x_authctxt = NULL;
73static int one = 1;
74
75typedef struct Authmethod Authmethod;
76struct Authmethod {
77 char *name;
78 int (*userauth)(Authctxt *authctxt);
79 int *enabled;
80};
81
Damien Millereba71ba2000-04-29 23:57:08 +100082/* protocol */
83
Damien Miller62cee002000-09-23 17:15:56 +110084void input_service_request(int type, int plen, void *ctxt);
85void input_userauth_request(int type, int plen, void *ctxt);
86void protocol_error(int type, int plen, void *ctxt);
Damien Millereba71ba2000-04-29 23:57:08 +100087
Damien Millereba71ba2000-04-29 23:57:08 +100088
89/* helper */
Damien Miller874d77b2000-10-14 16:23:11 +110090Authmethod *authmethod_lookup(const char *name);
91struct passwd *pwcopy(struct passwd *pw);
Damien Millereba71ba2000-04-29 23:57:08 +100092int user_dsa_key_allowed(struct passwd *pw, Key *key);
Damien Miller874d77b2000-10-14 16:23:11 +110093char *authmethods_get(void);
Damien Millereba71ba2000-04-29 23:57:08 +100094
Damien Miller874d77b2000-10-14 16:23:11 +110095/* auth */
96int userauth_none(Authctxt *authctxt);
97int userauth_passwd(Authctxt *authctxt);
98int userauth_pubkey(Authctxt *authctxt);
99int userauth_kbdint(Authctxt *authctxt);
100
101Authmethod authmethods[] = {
102 {"none",
103 userauth_none,
104 &one},
105 {"publickey",
106 userauth_pubkey,
107 &options.dsa_authentication},
108 {"keyboard-interactive",
109 userauth_kbdint,
110 &options.kbd_interactive_authentication},
111 {"password",
112 userauth_passwd,
113 &options.password_authentication},
114 {NULL, NULL, NULL}
Damien Millereba71ba2000-04-29 23:57:08 +1000115};
Damien Millereba71ba2000-04-29 23:57:08 +1000116
117/*
Damien Miller874d77b2000-10-14 16:23:11 +1100118 * loop until authctxt->success == TRUE
Damien Millereba71ba2000-04-29 23:57:08 +1000119 */
120
121void
122do_authentication2()
123{
Damien Miller874d77b2000-10-14 16:23:11 +1100124 Authctxt *authctxt = xmalloc(sizeof(*authctxt));
125 memset(authctxt, 'a', sizeof(*authctxt));
126 authctxt->valid = 0;
127 authctxt->attempt = 0;
128 authctxt->success = 0;
129 x_authctxt = authctxt; /*XXX*/
130
Damien Miller1cead2c2000-05-01 22:55:23 +1000131#ifdef KRB4
Damien Miller874d77b2000-10-14 16:23:11 +1100132 /* turn off kerberos, not supported by SSH2 */
Damien Miller35dabd02000-05-01 21:10:33 +1000133 options.kerberos_authentication = 0;
Damien Miller1cead2c2000-05-01 22:55:23 +1000134#endif
Damien Millereba71ba2000-04-29 23:57:08 +1000135 dispatch_init(&protocol_error);
136 dispatch_set(SSH2_MSG_SERVICE_REQUEST, &input_service_request);
Damien Miller874d77b2000-10-14 16:23:11 +1100137 dispatch_run(DISPATCH_BLOCK, &authctxt->success, authctxt);
Damien Millereba71ba2000-04-29 23:57:08 +1000138 do_authenticated2();
139}
140
141void
Damien Miller62cee002000-09-23 17:15:56 +1100142protocol_error(int type, int plen, void *ctxt)
Damien Millereba71ba2000-04-29 23:57:08 +1000143{
144 log("auth: protocol error: type %d plen %d", type, plen);
145 packet_start(SSH2_MSG_UNIMPLEMENTED);
146 packet_put_int(0);
147 packet_send();
148 packet_write_wait();
149}
150
151void
Damien Miller62cee002000-09-23 17:15:56 +1100152input_service_request(int type, int plen, void *ctxt)
Damien Millereba71ba2000-04-29 23:57:08 +1000153{
Damien Miller874d77b2000-10-14 16:23:11 +1100154 Authctxt *authctxt = ctxt;
Damien Millereba71ba2000-04-29 23:57:08 +1000155 unsigned int len;
156 int accept = 0;
157 char *service = packet_get_string(&len);
158 packet_done();
159
Damien Miller874d77b2000-10-14 16:23:11 +1100160 if (authctxt == NULL)
161 fatal("input_service_request: no authctxt");
162
Damien Millereba71ba2000-04-29 23:57:08 +1000163 if (strcmp(service, "ssh-userauth") == 0) {
Damien Miller874d77b2000-10-14 16:23:11 +1100164 if (!authctxt->success) {
Damien Millereba71ba2000-04-29 23:57:08 +1000165 accept = 1;
166 /* now we can handle user-auth requests */
167 dispatch_set(SSH2_MSG_USERAUTH_REQUEST, &input_userauth_request);
168 }
169 }
170 /* XXX all other service requests are denied */
171
172 if (accept) {
173 packet_start(SSH2_MSG_SERVICE_ACCEPT);
174 packet_put_cstring(service);
175 packet_send();
176 packet_write_wait();
177 } else {
178 debug("bad service request %s", service);
179 packet_disconnect("bad service request %s", service);
180 }
181 xfree(service);
182}
183
184void
Damien Miller62cee002000-09-23 17:15:56 +1100185input_userauth_request(int type, int plen, void *ctxt)
Damien Millereba71ba2000-04-29 23:57:08 +1000186{
Damien Miller874d77b2000-10-14 16:23:11 +1100187 Authctxt *authctxt = ctxt;
188 Authmethod *m = NULL;
189 char *user, *service, *method;
Damien Millereba71ba2000-04-29 23:57:08 +1000190 int authenticated = 0;
Damien Millereba71ba2000-04-29 23:57:08 +1000191
Damien Miller874d77b2000-10-14 16:23:11 +1100192 if (authctxt == NULL)
193 fatal("input_userauth_request: no authctxt");
194 if (authctxt->attempt++ >= AUTH_FAIL_MAX) {
Damien Millerd2c208a2000-05-17 22:00:02 +1000195#ifdef WITH_AIXAUTHENTICATE
196 loginfailed(user,get_canonical_hostname(),"ssh");
197#endif /* WITH_AIXAUTHENTICATE */
198 packet_disconnect("too many failed userauth_requests");
199 }
Damien Millereba71ba2000-04-29 23:57:08 +1000200
Damien Miller874d77b2000-10-14 16:23:11 +1100201 user = packet_get_string(NULL);
202 service = packet_get_string(NULL);
203 method = packet_get_string(NULL);
204 debug("userauth-request for user %s service %s method %s", user, service, method);
205 debug("attempt #%d", authctxt->attempt);
206
207 if (authctxt->attempt == 1) {
208 /* setup auth context */
209 struct passwd *pw = NULL;
210 setproctitle("%s", user);
211 pw = getpwnam(user);
212 if (pw && allowed_user(pw) && strcmp(service, "ssh-connection")==0) {
213 authctxt->pw = pwcopy(pw);
214 authctxt->valid = 1;
215 debug2("input_userauth_request: setting up authctxt for %s", user);
216#ifdef USE_PAM
217 start_pam(pw);
218#endif
219 } else {
220 log("input_userauth_request: illegal user %s", user);
221 }
222 authctxt->user = xstrdup(user);
223 authctxt->service = xstrdup(service);
224 } else if (authctxt->valid) {
225 if (strcmp(user, authctxt->user) != 0 ||
226 strcmp(service, authctxt->service) != 0) {
227 log("input_userauth_request: missmatch: (%s,%s)!=(%s,%s)",
228 user, service, authctxt->user, authctxt->service);
229 authctxt->valid = 0;
Damien Millereba71ba2000-04-29 23:57:08 +1000230 }
231 }
Damien Millerb70b61f2000-09-16 16:25:12 +1100232
Damien Miller874d77b2000-10-14 16:23:11 +1100233 m = authmethod_lookup(method);
234 if (m != NULL) {
235 debug2("input_userauth_request: try method %s", method);
236 authenticated = m->userauth(authctxt);
237 } else {
238 debug2("input_userauth_request: unsupported method %s", method);
239 }
240 if (!authctxt->valid && authenticated == 1) {
241 log("input_userauth_request: INTERNAL ERROR: authenticated invalid user %s service %s", user, method);
Damien Millerb70b61f2000-09-16 16:25:12 +1100242 authenticated = 0;
243 }
Damien Millerb70b61f2000-09-16 16:25:12 +1100244
Damien Miller874d77b2000-10-14 16:23:11 +1100245 /* Special handling for root */
246 if (authenticated == 1 &&
247 authctxt->valid && authctxt->pw->pw_uid == 0 && !options.permit_root_login) {
Damien Millereba71ba2000-04-29 23:57:08 +1000248 authenticated = 0;
Damien Miller874d77b2000-10-14 16:23:11 +1100249 log("ROOT LOGIN REFUSED FROM %.200s", get_canonical_hostname());
Damien Millereba71ba2000-04-29 23:57:08 +1000250 }
251
252#ifdef USE_PAM
Damien Miller874d77b2000-10-14 16:23:11 +1100253 if (authenticated && !do_pam_account(authctxt->pw->pw_name, NULL))
Damien Millerb70b61f2000-09-16 16:25:12 +1100254 authenticated = 0;
Damien Millereba71ba2000-04-29 23:57:08 +1000255#endif /* USE_PAM */
256
Damien Miller874d77b2000-10-14 16:23:11 +1100257 /* Log before sending the reply */
258 userauth_log(authctxt, authenticated, method);
259 userauth_reply(authctxt, authenticated);
260
261 xfree(service);
262 xfree(user);
263 xfree(method);
264}
265
266
267void
268userauth_log(Authctxt *authctxt, int authenticated, char *method)
269{
270 void (*authlog) (const char *fmt,...) = verbose;
271 char *user = NULL, *authmsg = NULL;
272
Damien Millere247cc42000-05-07 12:03:14 +1000273 /* Raise logging level */
274 if (authenticated == 1 ||
Damien Miller874d77b2000-10-14 16:23:11 +1100275 !authctxt->valid ||
276 authctxt->attempt >= AUTH_FAIL_LOG ||
Damien Millere247cc42000-05-07 12:03:14 +1000277 strcmp(method, "password") == 0)
278 authlog = log;
279
Damien Millereba71ba2000-04-29 23:57:08 +1000280 if (authenticated == 1) {
281 authmsg = "Accepted";
Damien Millere247cc42000-05-07 12:03:14 +1000282 } else if (authenticated == 0) {
283 authmsg = "Failed";
284 } else {
285 authmsg = "Postponed";
286 }
Damien Millere247cc42000-05-07 12:03:14 +1000287
Damien Miller874d77b2000-10-14 16:23:11 +1100288 if (authctxt->valid) {
289 user = authctxt->pw->pw_uid == 0 ? "ROOT" : authctxt->user;
290 } else {
291 user = "NOUSER";
292 }
293
294 authlog("%s %s for %.200s from %.200s port %d ssh2",
295 authmsg,
296 method,
297 user,
298 get_remote_ipaddr(),
299 get_remote_port());
300}
301
302void
303userauth_reply(Authctxt *authctxt, int authenticated)
304{
Damien Millere247cc42000-05-07 12:03:14 +1000305 /* XXX todo: check if multiple auth methods are needed */
306 if (authenticated == 1) {
Damien Millerd2c208a2000-05-17 22:00:02 +1000307#ifdef WITH_AIXAUTHENTICATE
308 /* We don't have a pty yet, so just label the line as "ssh" */
Damien Miller874d77b2000-10-14 16:23:11 +1100309 if (loginsuccess(user, get_canonical_hostname(), "ssh",
Damien Millerd2c208a2000-05-17 22:00:02 +1000310 &aixloginmsg) < 0)
311 aixloginmsg = NULL;
312#endif /* WITH_AIXAUTHENTICATE */
Damien Millereba71ba2000-04-29 23:57:08 +1000313 /* turn off userauth */
314 dispatch_set(SSH2_MSG_USERAUTH_REQUEST, &protocol_error);
315 packet_start(SSH2_MSG_USERAUTH_SUCCESS);
316 packet_send();
317 packet_write_wait();
318 /* now we can break out */
Damien Miller874d77b2000-10-14 16:23:11 +1100319 authctxt->success = 1;
Damien Millereba71ba2000-04-29 23:57:08 +1000320 } else if (authenticated == 0) {
Damien Miller874d77b2000-10-14 16:23:11 +1100321 char *methods = authmethods_get();
Damien Millereba71ba2000-04-29 23:57:08 +1000322 packet_start(SSH2_MSG_USERAUTH_FAILURE);
Damien Miller874d77b2000-10-14 16:23:11 +1100323 packet_put_cstring(methods);
324 packet_put_char(0); /* XXX partial success, unused */
Damien Millereba71ba2000-04-29 23:57:08 +1000325 packet_send();
326 packet_write_wait();
Damien Miller874d77b2000-10-14 16:23:11 +1100327 xfree(methods);
328 } else {
329 /* do nothing, we did already send a reply */
Damien Millereba71ba2000-04-29 23:57:08 +1000330 }
Damien Millereba71ba2000-04-29 23:57:08 +1000331}
332
333int
Damien Miller874d77b2000-10-14 16:23:11 +1100334userauth_none(Authctxt *authctxt)
Damien Millereba71ba2000-04-29 23:57:08 +1000335{
Damien Miller874d77b2000-10-14 16:23:11 +1100336 /* disable method "none", only allowed one time */
337 Authmethod *m = authmethod_lookup("none");
338 if (m != NULL)
339 m->enabled = NULL;
Damien Millereba71ba2000-04-29 23:57:08 +1000340 packet_done();
Damien Millerb8c656e2000-06-28 15:22:41 +1000341
Damien Miller874d77b2000-10-14 16:23:11 +1100342 if (authctxt->valid == 0)
343 return(0);
344
345#ifdef HAVE_CYGWIN
346 if (check_nt_auth(1, authctxt->pw->pw_uid) == 0)
347 return(0);
348#endif
Damien Millereba71ba2000-04-29 23:57:08 +1000349#ifdef USE_PAM
Damien Miller874d77b2000-10-14 16:23:11 +1100350 return auth_pam_password(authctxt->pw, "");
Damien Millerb8c656e2000-06-28 15:22:41 +1000351#elif defined(HAVE_OSF_SIA)
Damien Miller874d77b2000-10-14 16:23:11 +1100352 return (sia_validate_user(NULL, saved_argc, saved_argv,
353 get_canonical_hostname(), authctxt->pw->pw_name, NULL,
354 0, NULL, "") == SIASUCCESS);
Damien Millerb8c656e2000-06-28 15:22:41 +1000355#else /* !HAVE_OSF_SIA && !USE_PAM */
Damien Miller874d77b2000-10-14 16:23:11 +1100356 return auth_password(authctxt->pw, "");
Damien Millereba71ba2000-04-29 23:57:08 +1000357#endif /* USE_PAM */
358}
Damien Miller874d77b2000-10-14 16:23:11 +1100359
Damien Millereba71ba2000-04-29 23:57:08 +1000360int
Damien Miller874d77b2000-10-14 16:23:11 +1100361userauth_passwd(Authctxt *authctxt)
Damien Millereba71ba2000-04-29 23:57:08 +1000362{
363 char *password;
364 int authenticated = 0;
365 int change;
366 unsigned int len;
367 change = packet_get_char();
368 if (change)
369 log("password change not supported");
370 password = packet_get_string(&len);
371 packet_done();
Damien Miller874d77b2000-10-14 16:23:11 +1100372 if (authctxt->valid &&
373#ifdef HAVE_CYGWIN
374 check_nt_auth(1, authctxt->pw->pw_uid) &&
375#endif
Damien Millereba71ba2000-04-29 23:57:08 +1000376#ifdef USE_PAM
Damien Miller874d77b2000-10-14 16:23:11 +1100377 auth_pam_password(authctxt->pw, password) == 1)
Damien Millerb8c656e2000-06-28 15:22:41 +1000378#elif defined(HAVE_OSF_SIA)
379 sia_validate_user(NULL, saved_argc, saved_argv,
Damien Miller874d77b2000-10-14 16:23:11 +1100380 get_canonical_hostname(), authctxt->pw->pw_name, NULL, 0,
Damien Millerb8c656e2000-06-28 15:22:41 +1000381 NULL, password) == SIASUCCESS)
382#else /* !USE_PAM && !HAVE_OSF_SIA */
Damien Miller874d77b2000-10-14 16:23:11 +1100383 auth_password(authctxt->pw, password) == 1)
Damien Millereba71ba2000-04-29 23:57:08 +1000384#endif /* USE_PAM */
385 authenticated = 1;
386 memset(password, 0, len);
387 xfree(password);
388 return authenticated;
389}
Damien Miller874d77b2000-10-14 16:23:11 +1100390
Damien Millereba71ba2000-04-29 23:57:08 +1000391int
Damien Miller874d77b2000-10-14 16:23:11 +1100392userauth_kbdint(Authctxt *authctxt)
393{
394 int authenticated = 0;
395 char *lang = NULL;
396 char *devs = NULL;
397
398 lang = packet_get_string(NULL);
399 devs = packet_get_string(NULL);
400 packet_done();
401
402 debug("keyboard-interactive language %s devs %s", lang, devs);
403#ifdef SKEY
404 /* XXX hardcoded, we should look at devs */
405 if (options.skey_authentication != 0)
406 authenticated = auth2_skey(authctxt);
407#endif
408 xfree(lang);
409 xfree(devs);
410#ifdef HAVE_CYGWIN
411 if (check_nt_auth(0, authctxt->pw->pw_uid) == 0)
412 return(0);
413#endif
414 return authenticated;
415}
416
417int
418userauth_pubkey(Authctxt *authctxt)
Damien Millereba71ba2000-04-29 23:57:08 +1000419{
420 Buffer b;
421 Key *key;
422 char *pkalg, *pkblob, *sig;
423 unsigned int alen, blen, slen;
424 int have_sig;
425 int authenticated = 0;
426
Damien Miller874d77b2000-10-14 16:23:11 +1100427 if (!authctxt->valid) {
428 debug2("userauth_pubkey: disabled because of invalid user");
Damien Millereba71ba2000-04-29 23:57:08 +1000429 return 0;
430 }
431 have_sig = packet_get_char();
432 pkalg = packet_get_string(&alen);
433 if (strcmp(pkalg, KEX_DSS) != 0) {
Damien Millereba71ba2000-04-29 23:57:08 +1000434 log("bad pkalg %s", pkalg); /*XXX*/
Damien Miller874d77b2000-10-14 16:23:11 +1100435 xfree(pkalg);
Damien Millereba71ba2000-04-29 23:57:08 +1000436 return 0;
437 }
438 pkblob = packet_get_string(&blen);
439 key = dsa_key_from_blob(pkblob, blen);
440 if (key != NULL) {
441 if (have_sig) {
442 sig = packet_get_string(&slen);
443 packet_done();
444 buffer_init(&b);
Damien Miller6536c7d2000-06-22 21:32:31 +1000445 if (datafellows & SSH_COMPAT_SESSIONID_ENCODING) {
446 buffer_put_string(&b, session_id2, session_id2_len);
447 } else {
448 buffer_append(&b, session_id2, session_id2_len);
449 }
Damien Millerf6d9e222000-06-18 14:50:44 +1000450 /* reconstruct packet */
Damien Millereba71ba2000-04-29 23:57:08 +1000451 buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
Damien Miller874d77b2000-10-14 16:23:11 +1100452 buffer_put_cstring(&b, authctxt->user);
Damien Millerf6d9e222000-06-18 14:50:44 +1000453 buffer_put_cstring(&b,
454 datafellows & SSH_BUG_PUBKEYAUTH ?
455 "ssh-userauth" :
Damien Miller874d77b2000-10-14 16:23:11 +1100456 authctxt->service);
Damien Millerf6d9e222000-06-18 14:50:44 +1000457 buffer_put_cstring(&b, "publickey");
458 buffer_put_char(&b, have_sig);
459 buffer_put_cstring(&b, KEX_DSS);
460 buffer_put_string(&b, pkblob, blen);
Damien Millereba71ba2000-04-29 23:57:08 +1000461#ifdef DEBUG_DSS
462 buffer_dump(&b);
463#endif
464 /* test for correct signature */
Damien Miller874d77b2000-10-14 16:23:11 +1100465 if (user_dsa_key_allowed(authctxt->pw, key) &&
Damien Millereba71ba2000-04-29 23:57:08 +1000466 dsa_verify(key, sig, slen, buffer_ptr(&b), buffer_len(&b)) == 1)
467 authenticated = 1;
468 buffer_clear(&b);
469 xfree(sig);
470 } else {
Damien Miller874d77b2000-10-14 16:23:11 +1100471 debug("test whether pkalg/pkblob are acceptable");
Damien Millereba71ba2000-04-29 23:57:08 +1000472 packet_done();
Damien Miller874d77b2000-10-14 16:23:11 +1100473
Damien Millereba71ba2000-04-29 23:57:08 +1000474 /* XXX fake reply and always send PK_OK ? */
Damien Millere247cc42000-05-07 12:03:14 +1000475 /*
476 * XXX this allows testing whether a user is allowed
477 * to login: if you happen to have a valid pubkey this
478 * message is sent. the message is NEVER sent at all
479 * if a user is not allowed to login. is this an
480 * issue? -markus
481 */
Damien Miller874d77b2000-10-14 16:23:11 +1100482 if (user_dsa_key_allowed(authctxt->pw, key)) {
Damien Millereba71ba2000-04-29 23:57:08 +1000483 packet_start(SSH2_MSG_USERAUTH_PK_OK);
484 packet_put_string(pkalg, alen);
485 packet_put_string(pkblob, blen);
486 packet_send();
487 packet_write_wait();
488 authenticated = -1;
489 }
490 }
Damien Miller874d77b2000-10-14 16:23:11 +1100491 if (authenticated != 1)
492 auth_clear_options();
Damien Millereba71ba2000-04-29 23:57:08 +1000493 key_free(key);
494 }
495 xfree(pkalg);
496 xfree(pkblob);
Damien Miller874d77b2000-10-14 16:23:11 +1100497#ifdef HAVE_CYGWIN
498 if (check_nt_auth(0, authctxt->pw->pw_uid) == 0)
499 return(0);
500#endif
Damien Millereba71ba2000-04-29 23:57:08 +1000501 return authenticated;
502}
503
Damien Miller874d77b2000-10-14 16:23:11 +1100504/* get current user */
Damien Millereba71ba2000-04-29 23:57:08 +1000505
506struct passwd*
507auth_get_user(void)
508{
Damien Miller874d77b2000-10-14 16:23:11 +1100509 return (x_authctxt != NULL && x_authctxt->valid) ? x_authctxt->pw : NULL;
Damien Millereba71ba2000-04-29 23:57:08 +1000510}
511
Damien Miller874d77b2000-10-14 16:23:11 +1100512#define DELIM ","
Damien Millereba71ba2000-04-29 23:57:08 +1000513
Damien Miller874d77b2000-10-14 16:23:11 +1100514char *
515authmethods_get(void)
516{
517 Authmethod *method = NULL;
518 unsigned int size = 0;
519 char *list;
520
521 for (method = authmethods; method->name != NULL; method++) {
522 if (strcmp(method->name, "none") == 0)
523 continue;
524 if (method->enabled != NULL && *(method->enabled) != 0) {
525 if (size != 0)
526 size += strlen(DELIM);
527 size += strlen(method->name);
Damien Millereba71ba2000-04-29 23:57:08 +1000528 }
529 }
Damien Miller874d77b2000-10-14 16:23:11 +1100530 size++; /* trailing '\0' */
531 list = xmalloc(size);
532 list[0] = '\0';
533
534 for (method = authmethods; method->name != NULL; method++) {
535 if (strcmp(method->name, "none") == 0)
536 continue;
537 if (method->enabled != NULL && *(method->enabled) != 0) {
538 if (list[0] != '\0')
539 strlcat(list, DELIM, size);
540 strlcat(list, method->name, size);
541 }
542 }
543 return list;
544}
545
546Authmethod *
547authmethod_lookup(const char *name)
548{
549 Authmethod *method = NULL;
550 if (name != NULL)
551 for (method = authmethods; method->name != NULL; method++)
552 if (method->enabled != NULL &&
553 *(method->enabled) != 0 &&
554 strcmp(name, method->name) == 0)
555 return method;
556 debug2("Unrecognized authentication method name: %s", name ? name : "NULL");
557 return NULL;
Damien Millereba71ba2000-04-29 23:57:08 +1000558}
559
560/* return 1 if user allows given key */
561int
562user_dsa_key_allowed(struct passwd *pw, Key *key)
563{
564 char line[8192], file[1024];
565 int found_key = 0;
566 unsigned int bits = -1;
567 FILE *f;
568 unsigned long linenum = 0;
569 struct stat st;
570 Key *found;
571
Damien Miller874d77b2000-10-14 16:23:11 +1100572 if (pw == NULL)
573 return 0;
574
Damien Millereba71ba2000-04-29 23:57:08 +1000575 /* Temporarily use the user's uid. */
576 temporarily_use_uid(pw->pw_uid);
577
578 /* The authorized keys. */
579 snprintf(file, sizeof file, "%.500s/%.100s", pw->pw_dir,
580 SSH_USER_PERMITTED_KEYS2);
581
582 /* Fail quietly if file does not exist */
583 if (stat(file, &st) < 0) {
584 /* Restore the privileged uid. */
585 restore_uid();
586 return 0;
587 }
588 /* Open the file containing the authorized keys. */
589 f = fopen(file, "r");
590 if (!f) {
591 /* Restore the privileged uid. */
592 restore_uid();
593 return 0;
594 }
595 if (options.strict_modes) {
596 int fail = 0;
597 char buf[1024];
598 /* Check open file in order to avoid open/stat races */
599 if (fstat(fileno(f), &st) < 0 ||
600 (st.st_uid != 0 && st.st_uid != pw->pw_uid) ||
601 (st.st_mode & 022) != 0) {
Damien Millerd3444942000-09-30 14:20:03 +1100602 snprintf(buf, sizeof buf,
603 "%s authentication refused for %.100s: "
604 "bad ownership or modes for '%s'.",
605 key_type(key), pw->pw_name, file);
Damien Millereba71ba2000-04-29 23:57:08 +1000606 fail = 1;
607 } else {
608 /* Check path to SSH_USER_PERMITTED_KEYS */
609 int i;
610 static const char *check[] = {
611 "", SSH_USER_DIR, NULL
612 };
613 for (i = 0; check[i]; i++) {
614 snprintf(line, sizeof line, "%.500s/%.100s",
615 pw->pw_dir, check[i]);
616 if (stat(line, &st) < 0 ||
617 (st.st_uid != 0 && st.st_uid != pw->pw_uid) ||
618 (st.st_mode & 022) != 0) {
619 snprintf(buf, sizeof buf,
Damien Millerd3444942000-09-30 14:20:03 +1100620 "%s authentication refused for %.100s: "
Damien Millereba71ba2000-04-29 23:57:08 +1000621 "bad ownership or modes for '%s'.",
Damien Millerd3444942000-09-30 14:20:03 +1100622 key_type(key), pw->pw_name, line);
Damien Millereba71ba2000-04-29 23:57:08 +1000623 fail = 1;
624 break;
625 }
626 }
627 }
628 if (fail) {
Damien Millereba71ba2000-04-29 23:57:08 +1000629 fclose(f);
Damien Miller37023962000-07-11 17:31:38 +1000630 log("%s",buf);
Damien Millereba71ba2000-04-29 23:57:08 +1000631 restore_uid();
632 return 0;
633 }
634 }
635 found_key = 0;
Damien Millerd3444942000-09-30 14:20:03 +1100636 found = key_new(key->type);
Damien Millereba71ba2000-04-29 23:57:08 +1000637
638 while (fgets(line, sizeof(line), f)) {
Damien Millerf6d9e222000-06-18 14:50:44 +1000639 char *cp, *options = NULL;
Damien Millereba71ba2000-04-29 23:57:08 +1000640 linenum++;
641 /* Skip leading whitespace, empty and comment lines. */
642 for (cp = line; *cp == ' ' || *cp == '\t'; cp++)
643 ;
644 if (!*cp || *cp == '\n' || *cp == '#')
645 continue;
Damien Millerf6d9e222000-06-18 14:50:44 +1000646
Damien Millereba71ba2000-04-29 23:57:08 +1000647 bits = key_read(found, &cp);
Damien Millerf6d9e222000-06-18 14:50:44 +1000648 if (bits == 0) {
649 /* no key? check if there are options for this key */
650 int quoted = 0;
651 options = cp;
652 for (; *cp && (quoted || (*cp != ' ' && *cp != '\t')); cp++) {
653 if (*cp == '\\' && cp[1] == '"')
654 cp++; /* Skip both */
655 else if (*cp == '"')
656 quoted = !quoted;
657 }
658 /* Skip remaining whitespace. */
659 for (; *cp == ' ' || *cp == '\t'; cp++)
660 ;
661 bits = key_read(found, &cp);
662 if (bits == 0) {
663 /* still no key? advance to next line*/
664 continue;
665 }
666 }
667 if (key_equal(found, key) &&
668 auth_parse_options(pw, options, linenum) == 1) {
Damien Millereba71ba2000-04-29 23:57:08 +1000669 found_key = 1;
670 debug("matching key found: file %s, line %ld",
671 file, linenum);
672 break;
673 }
674 }
675 restore_uid();
676 fclose(f);
677 key_free(found);
678 return found_key;
679}
Damien Miller874d77b2000-10-14 16:23:11 +1100680
681struct passwd *
682pwcopy(struct passwd *pw)
683{
684 struct passwd *copy = xmalloc(sizeof(*copy));
685 memset(copy, 0, sizeof(*copy));
686 copy->pw_name = xstrdup(pw->pw_name);
687 copy->pw_passwd = xstrdup(pw->pw_passwd);
688 copy->pw_uid = pw->pw_uid;
689 copy->pw_gid = pw->pw_gid;
690#ifdef HAVE_PW_CLASS_IN_PASSWD
691 copy->pw_class = xstrdup(pw->pw_class);
692#endif
693 copy->pw_dir = xstrdup(pw->pw_dir);
694 copy->pw_shell = xstrdup(pw->pw_shell);
695 return copy;
696}