blob: f878b511f0ee7ac2b4dcf3bb19b6e94acda0240b [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 Lindstrom6328ab32002-03-22 02:54:23 +000031RCSID("$OpenBSD: auth-krb5.c,v 1.8 2002/03/19 10:49:35 markus 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
43#include <krb5.h>
44
45extern ServerOptions options;
46
47static int
48krb5_init(void *context)
49{
50 Authctxt *authctxt = (Authctxt *)context;
51 krb5_error_code problem;
52 static int cleanup_registered = 0;
Damien Millerdb95e4e2002-02-13 16:56:44 +110053
Damien Miller964fed52001-09-25 12:58:23 +100054 if (authctxt->krb5_ctx == NULL) {
55 problem = krb5_init_context(&authctxt->krb5_ctx);
56 if (problem)
57 return (problem);
58 krb5_init_ets(authctxt->krb5_ctx);
59 }
60 if (!cleanup_registered) {
61 fatal_add_cleanup(krb5_cleanup_proc, authctxt);
62 cleanup_registered = 1;
63 }
64 return (0);
65}
66
67/*
68 * Try krb5 authentication. server_user is passed for logging purposes
69 * only, in auth is received ticket, in client is returned principal
70 * from the ticket
71 */
Damien Millerdb95e4e2002-02-13 16:56:44 +110072int
Damien Miller964fed52001-09-25 12:58:23 +100073auth_krb5(Authctxt *authctxt, krb5_data *auth, char **client)
74{
75 krb5_error_code problem;
76 krb5_principal server;
77 krb5_data reply;
78 krb5_ticket *ticket;
Damien Miller61b05cf2001-11-14 00:02:10 +110079 int fd, ret;
80
81 ret = 0;
Damien Miller964fed52001-09-25 12:58:23 +100082 server = NULL;
83 ticket = NULL;
84 reply.length = 0;
Damien Millerdb95e4e2002-02-13 16:56:44 +110085
Damien Miller964fed52001-09-25 12:58:23 +100086 problem = krb5_init(authctxt);
Damien Millerdb95e4e2002-02-13 16:56:44 +110087 if (problem)
Damien Miller964fed52001-09-25 12:58:23 +100088 goto err;
Damien Millerdb95e4e2002-02-13 16:56:44 +110089
Damien Miller964fed52001-09-25 12:58:23 +100090 problem = krb5_auth_con_init(authctxt->krb5_ctx,
91 &authctxt->krb5_auth_ctx);
92 if (problem)
93 goto err;
Damien Millerdb95e4e2002-02-13 16:56:44 +110094
Damien Miller964fed52001-09-25 12:58:23 +100095 fd = packet_get_connection_in();
96 problem = krb5_auth_con_setaddrs_from_fd(authctxt->krb5_ctx,
97 authctxt->krb5_auth_ctx, &fd);
98 if (problem)
99 goto err;
Damien Millerdb95e4e2002-02-13 16:56:44 +1100100
Damien Miller964fed52001-09-25 12:58:23 +1000101 problem = krb5_sname_to_principal(authctxt->krb5_ctx, NULL, NULL ,
102 KRB5_NT_SRV_HST, &server);
103 if (problem)
104 goto err;
Damien Millerdb95e4e2002-02-13 16:56:44 +1100105
Damien Miller964fed52001-09-25 12:58:23 +1000106 problem = krb5_rd_req(authctxt->krb5_ctx, &authctxt->krb5_auth_ctx,
107 auth, server, NULL, NULL, &ticket);
108 if (problem)
109 goto err;
Damien Millerdb95e4e2002-02-13 16:56:44 +1100110
Damien Miller964fed52001-09-25 12:58:23 +1000111 problem = krb5_copy_principal(authctxt->krb5_ctx, ticket->client,
112 &authctxt->krb5_user);
113 if (problem)
114 goto err;
Damien Millerdb95e4e2002-02-13 16:56:44 +1100115
Damien Miller964fed52001-09-25 12:58:23 +1000116 /* if client wants mutual auth */
117 problem = krb5_mk_rep(authctxt->krb5_ctx, authctxt->krb5_auth_ctx,
118 &reply);
119 if (problem)
120 goto err;
Damien Millerdb95e4e2002-02-13 16:56:44 +1100121
Damien Miller964fed52001-09-25 12:58:23 +1000122 /* Check .k5login authorization now. */
123 if (!krb5_kuserok(authctxt->krb5_ctx, authctxt->krb5_user,
124 authctxt->pw->pw_name))
125 goto err;
Damien Millerdb95e4e2002-02-13 16:56:44 +1100126
Damien Miller964fed52001-09-25 12:58:23 +1000127 if (client)
128 krb5_unparse_name(authctxt->krb5_ctx, authctxt->krb5_user,
129 client);
Damien Millerdb95e4e2002-02-13 16:56:44 +1100130
Damien Miller964fed52001-09-25 12:58:23 +1000131 packet_start(SSH_SMSG_AUTH_KERBEROS_RESPONSE);
132 packet_put_string((char *) reply.data, reply.length);
133 packet_send();
134 packet_write_wait();
Damien Miller61b05cf2001-11-14 00:02:10 +1100135
136 ret = 1;
Damien Miller964fed52001-09-25 12:58:23 +1000137 err:
138 if (server)
139 krb5_free_principal(authctxt->krb5_ctx, server);
140 if (ticket)
141 krb5_free_ticket(authctxt->krb5_ctx, ticket);
142 if (reply.length)
143 xfree(reply.data);
Damien Millerdb95e4e2002-02-13 16:56:44 +1100144
Ben Lindstromb8550282002-02-26 17:46:11 +0000145 if (problem) {
146 if (authctxt->krb5_ctx != NULL)
147 debug("Kerberos v5 authentication failed: %s",
148 krb5_get_err_text(authctxt->krb5_ctx, problem));
149 else
150 debug("Kerberos v5 authentication failed: %d",
151 problem);
152 }
Damien Miller61b05cf2001-11-14 00:02:10 +1100153
154 return (ret);
Damien Miller964fed52001-09-25 12:58:23 +1000155}
156
157int
158auth_krb5_tgt(Authctxt *authctxt, krb5_data *tgt)
159{
160 krb5_error_code problem;
161 krb5_ccache ccache = NULL;
162 char *pname;
Damien Millerdb95e4e2002-02-13 16:56:44 +1100163
Damien Miller964fed52001-09-25 12:58:23 +1000164 if (authctxt->pw == NULL || authctxt->krb5_user == NULL)
165 return (0);
Damien Millerdb95e4e2002-02-13 16:56:44 +1100166
Damien Miller964fed52001-09-25 12:58:23 +1000167 temporarily_use_uid(authctxt->pw);
Damien Millerdb95e4e2002-02-13 16:56:44 +1100168
Damien Miller964fed52001-09-25 12:58:23 +1000169 problem = krb5_cc_gen_new(authctxt->krb5_ctx, &krb5_fcc_ops, &ccache);
170 if (problem)
171 goto fail;
Damien Millerdb95e4e2002-02-13 16:56:44 +1100172
Damien Miller964fed52001-09-25 12:58:23 +1000173 problem = krb5_cc_initialize(authctxt->krb5_ctx, ccache,
174 authctxt->krb5_user);
175 if (problem)
176 goto fail;
Damien Millerdb95e4e2002-02-13 16:56:44 +1100177
Damien Miller964fed52001-09-25 12:58:23 +1000178 problem = krb5_rd_cred2(authctxt->krb5_ctx, authctxt->krb5_auth_ctx,
179 ccache, tgt);
180 if (problem)
181 goto fail;
Damien Millerdb95e4e2002-02-13 16:56:44 +1100182
Damien Miller964fed52001-09-25 12:58:23 +1000183 authctxt->krb5_fwd_ccache = ccache;
184 ccache = NULL;
Damien Millerdb95e4e2002-02-13 16:56:44 +1100185
Damien Miller964fed52001-09-25 12:58:23 +1000186 authctxt->krb5_ticket_file = (char *)krb5_cc_get_name(authctxt->krb5_ctx, authctxt->krb5_fwd_ccache);
Damien Millerdb95e4e2002-02-13 16:56:44 +1100187
Damien Miller964fed52001-09-25 12:58:23 +1000188 problem = krb5_unparse_name(authctxt->krb5_ctx, authctxt->krb5_user,
189 &pname);
190 if (problem)
191 goto fail;
Damien Millerdb95e4e2002-02-13 16:56:44 +1100192
Damien Miller964fed52001-09-25 12:58:23 +1000193 debug("Kerberos v5 TGT accepted (%s)", pname);
Damien Millerdb95e4e2002-02-13 16:56:44 +1100194
Damien Miller964fed52001-09-25 12:58:23 +1000195 restore_uid();
Damien Millerdb95e4e2002-02-13 16:56:44 +1100196
Damien Miller964fed52001-09-25 12:58:23 +1000197 return (1);
Damien Millerdb95e4e2002-02-13 16:56:44 +1100198
Damien Miller964fed52001-09-25 12:58:23 +1000199 fail:
200 if (problem)
201 debug("Kerberos v5 TGT passing failed: %s",
202 krb5_get_err_text(authctxt->krb5_ctx, problem));
203 if (ccache)
204 krb5_cc_destroy(authctxt->krb5_ctx, ccache);
Damien Millerdb95e4e2002-02-13 16:56:44 +1100205
Damien Miller964fed52001-09-25 12:58:23 +1000206 restore_uid();
Damien Millerdb95e4e2002-02-13 16:56:44 +1100207
Damien Miller964fed52001-09-25 12:58:23 +1000208 return (0);
209}
210
211int
212auth_krb5_password(Authctxt *authctxt, const char *password)
213{
214 krb5_error_code problem;
Damien Millerdb95e4e2002-02-13 16:56:44 +1100215
Damien Miller964fed52001-09-25 12:58:23 +1000216 if (authctxt->pw == NULL)
217 return (0);
Damien Millerdb95e4e2002-02-13 16:56:44 +1100218
Damien Miller964fed52001-09-25 12:58:23 +1000219 temporarily_use_uid(authctxt->pw);
Damien Millerdb95e4e2002-02-13 16:56:44 +1100220
Damien Miller964fed52001-09-25 12:58:23 +1000221 problem = krb5_init(authctxt);
222 if (problem)
223 goto out;
Damien Millerdb95e4e2002-02-13 16:56:44 +1100224
Damien Miller964fed52001-09-25 12:58:23 +1000225 problem = krb5_parse_name(authctxt->krb5_ctx, authctxt->pw->pw_name,
226 &authctxt->krb5_user);
227 if (problem)
228 goto out;
Damien Millerdb95e4e2002-02-13 16:56:44 +1100229
Damien Miller964fed52001-09-25 12:58:23 +1000230 problem = krb5_cc_gen_new(authctxt->krb5_ctx, &krb5_mcc_ops,
231 &authctxt->krb5_fwd_ccache);
232 if (problem)
233 goto out;
Damien Millerdb95e4e2002-02-13 16:56:44 +1100234
Damien Miller964fed52001-09-25 12:58:23 +1000235 problem = krb5_cc_initialize(authctxt->krb5_ctx,
236 authctxt->krb5_fwd_ccache, authctxt->krb5_user);
237 if (problem)
238 goto out;
Damien Millerdb95e4e2002-02-13 16:56:44 +1100239
240 restore_uid();
Damien Miller964fed52001-09-25 12:58:23 +1000241 problem = krb5_verify_user(authctxt->krb5_ctx, authctxt->krb5_user,
242 authctxt->krb5_fwd_ccache, password, 1, NULL);
Damien Millerdb95e4e2002-02-13 16:56:44 +1100243 temporarily_use_uid(authctxt->pw);
244
Damien Miller964fed52001-09-25 12:58:23 +1000245 if (problem)
246 goto out;
Damien Millerdb95e4e2002-02-13 16:56:44 +1100247
Damien Miller964fed52001-09-25 12:58:23 +1000248 authctxt->krb5_ticket_file = (char *)krb5_cc_get_name(authctxt->krb5_ctx, authctxt->krb5_fwd_ccache);
Damien Millerdb95e4e2002-02-13 16:56:44 +1100249
Damien Miller964fed52001-09-25 12:58:23 +1000250 out:
251 restore_uid();
Damien Millerdb95e4e2002-02-13 16:56:44 +1100252
Damien Miller964fed52001-09-25 12:58:23 +1000253 if (problem) {
Ben Lindstromb8550282002-02-26 17:46:11 +0000254 if (authctxt->krb5_ctx != NULL)
255 debug("Kerberos password authentication failed: %s",
256 krb5_get_err_text(authctxt->krb5_ctx, problem));
257 else
258 debug("Kerberos password authentication failed: %d",
259 problem);
Damien Millerdb95e4e2002-02-13 16:56:44 +1100260
Damien Miller964fed52001-09-25 12:58:23 +1000261 krb5_cleanup_proc(authctxt);
Damien Millerdb95e4e2002-02-13 16:56:44 +1100262
Damien Miller964fed52001-09-25 12:58:23 +1000263 if (options.kerberos_or_local_passwd)
264 return (-1);
265 else
266 return (0);
267 }
268 return (1);
269}
270
271void
272krb5_cleanup_proc(void *context)
273{
274 Authctxt *authctxt = (Authctxt *)context;
Damien Millerdb95e4e2002-02-13 16:56:44 +1100275
Damien Miller964fed52001-09-25 12:58:23 +1000276 debug("krb5_cleanup_proc called");
277 if (authctxt->krb5_fwd_ccache) {
278 krb5_cc_destroy(authctxt->krb5_ctx, authctxt->krb5_fwd_ccache);
279 authctxt->krb5_fwd_ccache = NULL;
280 }
281 if (authctxt->krb5_user) {
282 krb5_free_principal(authctxt->krb5_ctx, authctxt->krb5_user);
283 authctxt->krb5_user = NULL;
284 }
285 if (authctxt->krb5_auth_ctx) {
286 krb5_auth_con_free(authctxt->krb5_ctx,
287 authctxt->krb5_auth_ctx);
288 authctxt->krb5_auth_ctx = NULL;
289 }
290 if (authctxt->krb5_ctx) {
291 krb5_free_context(authctxt->krb5_ctx);
292 authctxt->krb5_ctx = NULL;
293 }
294}
295
296#endif /* KRB5 */