blob: 0a6f826e79db48dff9987a7709ba07caf3ecdcfc [file] [log] [blame]
Damien Miller964fed52001-09-25 12:58:23 +10001/*
2 * Kerberos v5 authentication and ticket-passing routines.
Ben Lindstrom6328ab32002-03-22 02:54:23 +00003 *
Damien Miller964fed52001-09-25 12:58:23 +10004 * $FreeBSD: src/crypto/openssh/auth-krb5.c,v 1.6 2001/02/13 16:58:04 assar Exp $
Damien Miller964fed52001-09-25 12:58:23 +10005 */
Ben Lindstromeacc71b2002-03-22 01:22:27 +00006/*
7 * Copyright (c) 2002 Daniel Kouril. All rights reserved.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 */
Damien Miller964fed52001-09-25 12:58:23 +100029
30#include "includes.h"
Ben Lindstrom93576d92002-12-23 02:06:19 +000031RCSID("$OpenBSD: auth-krb5.c,v 1.10 2002/11/21 23:03:51 deraadt Exp $");
Ben Lindstrom05764b92002-03-05 01:53:02 +000032
Damien Miller964fed52001-09-25 12:58:23 +100033#include "ssh.h"
34#include "ssh1.h"
35#include "packet.h"
36#include "xmalloc.h"
37#include "log.h"
38#include "servconf.h"
39#include "uidswap.h"
40#include "auth.h"
41
42#ifdef KRB5
Damien Miller9c617692003-05-14 14:31:11 +100043
Damien Miller964fed52001-09-25 12:58:23 +100044#include <krb5.h>
Damien Millerfd4c9ee2002-04-13 11:04:40 +100045#ifndef HEIMDAL
46#define krb5_get_err_text(context,code) error_message(code)
47#endif /* !HEIMDAL */
Damien Miller964fed52001-09-25 12:58:23 +100048
49extern ServerOptions options;
50
51static int
52krb5_init(void *context)
53{
54 Authctxt *authctxt = (Authctxt *)context;
55 krb5_error_code problem;
56 static int cleanup_registered = 0;
Damien Millerdb95e4e2002-02-13 16:56:44 +110057
Damien Miller964fed52001-09-25 12:58:23 +100058 if (authctxt->krb5_ctx == NULL) {
59 problem = krb5_init_context(&authctxt->krb5_ctx);
60 if (problem)
61 return (problem);
62 krb5_init_ets(authctxt->krb5_ctx);
63 }
64 if (!cleanup_registered) {
65 fatal_add_cleanup(krb5_cleanup_proc, authctxt);
66 cleanup_registered = 1;
67 }
68 return (0);
69}
70
71/*
72 * Try krb5 authentication. server_user is passed for logging purposes
73 * only, in auth is received ticket, in client is returned principal
74 * from the ticket
75 */
Damien Millerdb95e4e2002-02-13 16:56:44 +110076int
Damien Miller25162f22002-09-12 09:47:29 +100077auth_krb5(Authctxt *authctxt, krb5_data *auth, char **client, krb5_data *reply)
Damien Miller964fed52001-09-25 12:58:23 +100078{
79 krb5_error_code problem;
80 krb5_principal server;
Damien Miller964fed52001-09-25 12:58:23 +100081 krb5_ticket *ticket;
Damien Miller61b05cf2001-11-14 00:02:10 +110082 int fd, ret;
83
84 ret = 0;
Damien Miller964fed52001-09-25 12:58:23 +100085 server = NULL;
86 ticket = NULL;
Damien Miller25162f22002-09-12 09:47:29 +100087 reply->length = 0;
Damien Millerdb95e4e2002-02-13 16:56:44 +110088
Damien Miller964fed52001-09-25 12:58:23 +100089 problem = krb5_init(authctxt);
Damien Millerdb95e4e2002-02-13 16:56:44 +110090 if (problem)
Damien Miller964fed52001-09-25 12:58:23 +100091 goto err;
Damien Millerdb95e4e2002-02-13 16:56:44 +110092
Damien Miller964fed52001-09-25 12:58:23 +100093 problem = krb5_auth_con_init(authctxt->krb5_ctx,
94 &authctxt->krb5_auth_ctx);
95 if (problem)
96 goto err;
Damien Millerdb95e4e2002-02-13 16:56:44 +110097
Damien Miller964fed52001-09-25 12:58:23 +100098 fd = packet_get_connection_in();
Damien Millerfd4c9ee2002-04-13 11:04:40 +100099#ifdef HEIMDAL
Damien Miller964fed52001-09-25 12:58:23 +1000100 problem = krb5_auth_con_setaddrs_from_fd(authctxt->krb5_ctx,
101 authctxt->krb5_auth_ctx, &fd);
Damien Millerfd4c9ee2002-04-13 11:04:40 +1000102#else
103 problem = krb5_auth_con_genaddrs(authctxt->krb5_ctx,
104 authctxt->krb5_auth_ctx,fd,
105 KRB5_AUTH_CONTEXT_GENERATE_REMOTE_FULL_ADDR |
106 KRB5_AUTH_CONTEXT_GENERATE_LOCAL_FULL_ADDR);
107#endif
Damien Miller964fed52001-09-25 12:58:23 +1000108 if (problem)
109 goto err;
Damien Millerdb95e4e2002-02-13 16:56:44 +1100110
Ben Lindstrom93576d92002-12-23 02:06:19 +0000111 problem = krb5_sname_to_principal(authctxt->krb5_ctx, NULL, NULL,
Damien Miller964fed52001-09-25 12:58:23 +1000112 KRB5_NT_SRV_HST, &server);
113 if (problem)
114 goto err;
Damien Millerdb95e4e2002-02-13 16:56:44 +1100115
Damien Miller964fed52001-09-25 12:58:23 +1000116 problem = krb5_rd_req(authctxt->krb5_ctx, &authctxt->krb5_auth_ctx,
117 auth, server, NULL, NULL, &ticket);
118 if (problem)
119 goto err;
Damien Millerdb95e4e2002-02-13 16:56:44 +1100120
Damien Millerfd4c9ee2002-04-13 11:04:40 +1000121#ifdef HEIMDAL
Damien Miller964fed52001-09-25 12:58:23 +1000122 problem = krb5_copy_principal(authctxt->krb5_ctx, ticket->client,
123 &authctxt->krb5_user);
Damien Millerfd4c9ee2002-04-13 11:04:40 +1000124#else
125 problem = krb5_copy_principal(authctxt->krb5_ctx,
126 ticket->enc_part2->client,
127 &authctxt->krb5_user);
128#endif
Damien Miller964fed52001-09-25 12:58:23 +1000129 if (problem)
130 goto err;
Damien Millerdb95e4e2002-02-13 16:56:44 +1100131
Damien Miller964fed52001-09-25 12:58:23 +1000132 /* if client wants mutual auth */
133 problem = krb5_mk_rep(authctxt->krb5_ctx, authctxt->krb5_auth_ctx,
Damien Miller25162f22002-09-12 09:47:29 +1000134 reply);
Damien Miller964fed52001-09-25 12:58:23 +1000135 if (problem)
136 goto err;
Damien Millerdb95e4e2002-02-13 16:56:44 +1100137
Damien Miller964fed52001-09-25 12:58:23 +1000138 /* Check .k5login authorization now. */
139 if (!krb5_kuserok(authctxt->krb5_ctx, authctxt->krb5_user,
140 authctxt->pw->pw_name))
141 goto err;
Damien Millerdb95e4e2002-02-13 16:56:44 +1100142
Damien Miller964fed52001-09-25 12:58:23 +1000143 if (client)
144 krb5_unparse_name(authctxt->krb5_ctx, authctxt->krb5_user,
145 client);
Damien Millerdb95e4e2002-02-13 16:56:44 +1100146
Damien Miller61b05cf2001-11-14 00:02:10 +1100147 ret = 1;
Damien Miller964fed52001-09-25 12:58:23 +1000148 err:
149 if (server)
150 krb5_free_principal(authctxt->krb5_ctx, server);
151 if (ticket)
152 krb5_free_ticket(authctxt->krb5_ctx, ticket);
Damien Miller25162f22002-09-12 09:47:29 +1000153 if (!ret && reply->length) {
154 xfree(reply->data);
155 memset(reply, 0, sizeof(*reply));
156 }
Damien Millerdb95e4e2002-02-13 16:56:44 +1100157
Ben Lindstromb8550282002-02-26 17:46:11 +0000158 if (problem) {
159 if (authctxt->krb5_ctx != NULL)
160 debug("Kerberos v5 authentication failed: %s",
161 krb5_get_err_text(authctxt->krb5_ctx, problem));
162 else
163 debug("Kerberos v5 authentication failed: %d",
164 problem);
165 }
Damien Miller61b05cf2001-11-14 00:02:10 +1100166
167 return (ret);
Damien Miller964fed52001-09-25 12:58:23 +1000168}
169
170int
171auth_krb5_tgt(Authctxt *authctxt, krb5_data *tgt)
172{
173 krb5_error_code problem;
174 krb5_ccache ccache = NULL;
175 char *pname;
Damien Millerfd4c9ee2002-04-13 11:04:40 +1000176 krb5_creds **creds;
Damien Millerdb95e4e2002-02-13 16:56:44 +1100177
Damien Miller964fed52001-09-25 12:58:23 +1000178 if (authctxt->pw == NULL || authctxt->krb5_user == NULL)
179 return (0);
Damien Millerdb95e4e2002-02-13 16:56:44 +1100180
Damien Miller964fed52001-09-25 12:58:23 +1000181 temporarily_use_uid(authctxt->pw);
Damien Millerdb95e4e2002-02-13 16:56:44 +1100182
Damien Millerfd4c9ee2002-04-13 11:04:40 +1000183#ifdef HEIMDAL
Damien Miller964fed52001-09-25 12:58:23 +1000184 problem = krb5_cc_gen_new(authctxt->krb5_ctx, &krb5_fcc_ops, &ccache);
Damien Millerfd4c9ee2002-04-13 11:04:40 +1000185#else
186{
187 char ccname[40];
188 int tmpfd;
189
190 snprintf(ccname,sizeof(ccname),"FILE:/tmp/krb5cc_%d_XXXXXX",geteuid());
191
192 if ((tmpfd = mkstemp(ccname+strlen("FILE:")))==-1) {
Damien Miller996acd22003-04-09 20:59:48 +1000193 logit("mkstemp(): %.100s", strerror(errno));
Damien Millerfd4c9ee2002-04-13 11:04:40 +1000194 problem = errno;
195 goto fail;
196 }
197 if (fchmod(tmpfd,S_IRUSR | S_IWUSR) == -1) {
Damien Miller996acd22003-04-09 20:59:48 +1000198 logit("fchmod(): %.100s", strerror(errno));
Damien Millerfd4c9ee2002-04-13 11:04:40 +1000199 close(tmpfd);
200 problem = errno;
201 goto fail;
202 }
203 close(tmpfd);
204 problem = krb5_cc_resolve(authctxt->krb5_ctx, ccname, &ccache);
205}
206#endif
Damien Miller964fed52001-09-25 12:58:23 +1000207 if (problem)
208 goto fail;
Damien Millerdb95e4e2002-02-13 16:56:44 +1100209
Damien Miller964fed52001-09-25 12:58:23 +1000210 problem = krb5_cc_initialize(authctxt->krb5_ctx, ccache,
211 authctxt->krb5_user);
212 if (problem)
213 goto fail;
Damien Millerdb95e4e2002-02-13 16:56:44 +1100214
Damien Millerfd4c9ee2002-04-13 11:04:40 +1000215#ifdef HEIMDAL
Damien Miller964fed52001-09-25 12:58:23 +1000216 problem = krb5_rd_cred2(authctxt->krb5_ctx, authctxt->krb5_auth_ctx,
217 ccache, tgt);
218 if (problem)
219 goto fail;
Damien Millerfd4c9ee2002-04-13 11:04:40 +1000220#else
221 problem = krb5_rd_cred(authctxt->krb5_ctx, authctxt->krb5_auth_ctx,
222 tgt, &creds, NULL);
223 if (problem)
224 goto fail;
225 problem = krb5_cc_store_cred(authctxt->krb5_ctx, ccache, *creds);
226 if (problem)
227 goto fail;
228#endif
Damien Millerdb95e4e2002-02-13 16:56:44 +1100229
Damien Miller964fed52001-09-25 12:58:23 +1000230 authctxt->krb5_fwd_ccache = ccache;
231 ccache = NULL;
Damien Millerdb95e4e2002-02-13 16:56:44 +1100232
Damien Miller964fed52001-09-25 12:58:23 +1000233 authctxt->krb5_ticket_file = (char *)krb5_cc_get_name(authctxt->krb5_ctx, authctxt->krb5_fwd_ccache);
Damien Millerdb95e4e2002-02-13 16:56:44 +1100234
Damien Miller964fed52001-09-25 12:58:23 +1000235 problem = krb5_unparse_name(authctxt->krb5_ctx, authctxt->krb5_user,
236 &pname);
237 if (problem)
238 goto fail;
Damien Millerdb95e4e2002-02-13 16:56:44 +1100239
Damien Miller964fed52001-09-25 12:58:23 +1000240 debug("Kerberos v5 TGT accepted (%s)", pname);
Damien Millerdb95e4e2002-02-13 16:56:44 +1100241
Damien Miller964fed52001-09-25 12:58:23 +1000242 restore_uid();
Damien Millerdb95e4e2002-02-13 16:56:44 +1100243
Damien Miller964fed52001-09-25 12:58:23 +1000244 return (1);
Damien Millerdb95e4e2002-02-13 16:56:44 +1100245
Damien Miller964fed52001-09-25 12:58:23 +1000246 fail:
247 if (problem)
248 debug("Kerberos v5 TGT passing failed: %s",
249 krb5_get_err_text(authctxt->krb5_ctx, problem));
250 if (ccache)
251 krb5_cc_destroy(authctxt->krb5_ctx, ccache);
Damien Millerdb95e4e2002-02-13 16:56:44 +1100252
Damien Miller964fed52001-09-25 12:58:23 +1000253 restore_uid();
Damien Millerdb95e4e2002-02-13 16:56:44 +1100254
Damien Miller964fed52001-09-25 12:58:23 +1000255 return (0);
256}
257
258int
259auth_krb5_password(Authctxt *authctxt, const char *password)
260{
Damien Millerfd4c9ee2002-04-13 11:04:40 +1000261#ifndef HEIMDAL
262 krb5_creds creds;
263 krb5_principal server;
264 char ccname[40];
265 int tmpfd;
266#endif
Damien Miller964fed52001-09-25 12:58:23 +1000267 krb5_error_code problem;
Damien Millerdb95e4e2002-02-13 16:56:44 +1100268
Damien Miller964fed52001-09-25 12:58:23 +1000269 if (authctxt->pw == NULL)
270 return (0);
Damien Millerdb95e4e2002-02-13 16:56:44 +1100271
Damien Miller964fed52001-09-25 12:58:23 +1000272 temporarily_use_uid(authctxt->pw);
Damien Millerdb95e4e2002-02-13 16:56:44 +1100273
Damien Miller964fed52001-09-25 12:58:23 +1000274 problem = krb5_init(authctxt);
275 if (problem)
276 goto out;
Damien Millerdb95e4e2002-02-13 16:56:44 +1100277
Damien Miller964fed52001-09-25 12:58:23 +1000278 problem = krb5_parse_name(authctxt->krb5_ctx, authctxt->pw->pw_name,
279 &authctxt->krb5_user);
280 if (problem)
281 goto out;
Damien Millerdb95e4e2002-02-13 16:56:44 +1100282
Damien Millerfd4c9ee2002-04-13 11:04:40 +1000283#ifdef HEIMDAL
Damien Miller964fed52001-09-25 12:58:23 +1000284 problem = krb5_cc_gen_new(authctxt->krb5_ctx, &krb5_mcc_ops,
285 &authctxt->krb5_fwd_ccache);
286 if (problem)
287 goto out;
Damien Millerdb95e4e2002-02-13 16:56:44 +1100288
Damien Miller964fed52001-09-25 12:58:23 +1000289 problem = krb5_cc_initialize(authctxt->krb5_ctx,
290 authctxt->krb5_fwd_ccache, authctxt->krb5_user);
291 if (problem)
292 goto out;
Damien Millerdb95e4e2002-02-13 16:56:44 +1100293
294 restore_uid();
Damien Miller964fed52001-09-25 12:58:23 +1000295 problem = krb5_verify_user(authctxt->krb5_ctx, authctxt->krb5_user,
296 authctxt->krb5_fwd_ccache, password, 1, NULL);
Damien Millerdb95e4e2002-02-13 16:56:44 +1100297 temporarily_use_uid(authctxt->pw);
298
Damien Miller964fed52001-09-25 12:58:23 +1000299 if (problem)
300 goto out;
Damien Millerdb95e4e2002-02-13 16:56:44 +1100301
Damien Millerfd4c9ee2002-04-13 11:04:40 +1000302#else
303 problem = krb5_get_init_creds_password(authctxt->krb5_ctx, &creds,
304 authctxt->krb5_user, (char *)password, NULL, NULL, 0, NULL, NULL);
305 if (problem)
306 goto out;
307
308 problem = krb5_sname_to_principal(authctxt->krb5_ctx, NULL, NULL,
309 KRB5_NT_SRV_HST, &server);
310 if (problem)
311 goto out;
312
313 restore_uid();
314 problem = krb5_verify_init_creds(authctxt->krb5_ctx, &creds, server,
315 NULL, NULL, NULL);
316 krb5_free_principal(authctxt->krb5_ctx, server);
317 temporarily_use_uid(authctxt->pw);
318 if (problem)
319 goto out;
320
321 if (!krb5_kuserok(authctxt->krb5_ctx, authctxt->krb5_user,
322 authctxt->pw->pw_name)) {
Ben Lindstrom5a6abda2002-06-09 19:41:48 +0000323 problem = -1;
Damien Millerfd4c9ee2002-04-13 11:04:40 +1000324 goto out;
325 }
326
327 snprintf(ccname,sizeof(ccname),"FILE:/tmp/krb5cc_%d_XXXXXX",geteuid());
328
329 if ((tmpfd = mkstemp(ccname+strlen("FILE:")))==-1) {
Damien Miller996acd22003-04-09 20:59:48 +1000330 logit("mkstemp(): %.100s", strerror(errno));
Damien Millerfd4c9ee2002-04-13 11:04:40 +1000331 problem = errno;
332 goto out;
333 }
334
335 if (fchmod(tmpfd,S_IRUSR | S_IWUSR) == -1) {
Damien Miller996acd22003-04-09 20:59:48 +1000336 logit("fchmod(): %.100s", strerror(errno));
Damien Millerfd4c9ee2002-04-13 11:04:40 +1000337 close(tmpfd);
338 problem = errno;
339 goto out;
340 }
341 close(tmpfd);
342
343 problem = krb5_cc_resolve(authctxt->krb5_ctx, ccname, &authctxt->krb5_fwd_ccache);
344 if (problem)
345 goto out;
346
347 problem = krb5_cc_initialize(authctxt->krb5_ctx, authctxt->krb5_fwd_ccache,
348 authctxt->krb5_user);
349 if (problem)
350 goto out;
351
352 problem= krb5_cc_store_cred(authctxt->krb5_ctx, authctxt->krb5_fwd_ccache,
353 &creds);
354 if (problem)
355 goto out;
356#endif
357
Damien Miller964fed52001-09-25 12:58:23 +1000358 authctxt->krb5_ticket_file = (char *)krb5_cc_get_name(authctxt->krb5_ctx, authctxt->krb5_fwd_ccache);
Damien Millerdb95e4e2002-02-13 16:56:44 +1100359
Damien Miller964fed52001-09-25 12:58:23 +1000360 out:
361 restore_uid();
Damien Millerdb95e4e2002-02-13 16:56:44 +1100362
Damien Miller964fed52001-09-25 12:58:23 +1000363 if (problem) {
Damien Millerfd4c9ee2002-04-13 11:04:40 +1000364 if (authctxt->krb5_ctx != NULL && problem!=-1)
Ben Lindstromb8550282002-02-26 17:46:11 +0000365 debug("Kerberos password authentication failed: %s",
366 krb5_get_err_text(authctxt->krb5_ctx, problem));
367 else
368 debug("Kerberos password authentication failed: %d",
369 problem);
Damien Millerdb95e4e2002-02-13 16:56:44 +1100370
Damien Miller964fed52001-09-25 12:58:23 +1000371 krb5_cleanup_proc(authctxt);
Damien Millerdb95e4e2002-02-13 16:56:44 +1100372
Damien Miller964fed52001-09-25 12:58:23 +1000373 if (options.kerberos_or_local_passwd)
374 return (-1);
375 else
376 return (0);
377 }
378 return (1);
379}
380
381void
382krb5_cleanup_proc(void *context)
383{
384 Authctxt *authctxt = (Authctxt *)context;
Damien Millerdb95e4e2002-02-13 16:56:44 +1100385
Damien Miller964fed52001-09-25 12:58:23 +1000386 debug("krb5_cleanup_proc called");
387 if (authctxt->krb5_fwd_ccache) {
388 krb5_cc_destroy(authctxt->krb5_ctx, authctxt->krb5_fwd_ccache);
389 authctxt->krb5_fwd_ccache = NULL;
390 }
391 if (authctxt->krb5_user) {
392 krb5_free_principal(authctxt->krb5_ctx, authctxt->krb5_user);
393 authctxt->krb5_user = NULL;
394 }
395 if (authctxt->krb5_auth_ctx) {
396 krb5_auth_con_free(authctxt->krb5_ctx,
397 authctxt->krb5_auth_ctx);
398 authctxt->krb5_auth_ctx = NULL;
399 }
400 if (authctxt->krb5_ctx) {
401 krb5_free_context(authctxt->krb5_ctx);
402 authctxt->krb5_ctx = NULL;
403 }
404}
405
406#endif /* KRB5 */