blob: 64d613543db05d21ae648b71eee936727fd0c777 [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"
Darren Tuckerf4732f62005-11-22 19:42:42 +110031RCSID("$OpenBSD: auth-krb5.c,v 1.16 2005/11/21 09:42:10 dtucker 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;
Damien Millerdb95e4e2002-02-13 16:56:44 +110052
Damien Miller964fed52001-09-25 12:58:23 +100053 if (authctxt->krb5_ctx == NULL) {
54 problem = krb5_init_context(&authctxt->krb5_ctx);
55 if (problem)
56 return (problem);
Damien Miller964fed52001-09-25 12:58:23 +100057 }
Damien Miller964fed52001-09-25 12:58:23 +100058 return (0);
59}
60
Damien Miller964fed52001-09-25 12:58:23 +100061int
62auth_krb5_password(Authctxt *authctxt, const char *password)
63{
Damien Millerfd4c9ee2002-04-13 11:04:40 +100064#ifndef HEIMDAL
65 krb5_creds creds;
66 krb5_principal server;
Damien Miller787b2ec2003-11-21 23:56:47 +110067#endif
Damien Miller964fed52001-09-25 12:58:23 +100068 krb5_error_code problem;
Darren Tuckerec0943a2003-08-11 22:55:36 +100069 krb5_ccache ccache = NULL;
Damien Miller9c870f92004-04-16 22:47:55 +100070 int len;
Damien Millerdb95e4e2002-02-13 16:56:44 +110071
Damien Miller964fed52001-09-25 12:58:23 +100072 temporarily_use_uid(authctxt->pw);
Damien Millerdb95e4e2002-02-13 16:56:44 +110073
Damien Miller964fed52001-09-25 12:58:23 +100074 problem = krb5_init(authctxt);
75 if (problem)
76 goto out;
Damien Millerdb95e4e2002-02-13 16:56:44 +110077
Damien Miller964fed52001-09-25 12:58:23 +100078 problem = krb5_parse_name(authctxt->krb5_ctx, authctxt->pw->pw_name,
79 &authctxt->krb5_user);
80 if (problem)
81 goto out;
Damien Millerdb95e4e2002-02-13 16:56:44 +110082
Damien Millerfd4c9ee2002-04-13 11:04:40 +100083#ifdef HEIMDAL
Darren Tuckerec0943a2003-08-11 22:55:36 +100084 problem = krb5_cc_gen_new(authctxt->krb5_ctx, &krb5_mcc_ops, &ccache);
Damien Miller964fed52001-09-25 12:58:23 +100085 if (problem)
86 goto out;
Damien Millerdb95e4e2002-02-13 16:56:44 +110087
Darren Tuckerec0943a2003-08-11 22:55:36 +100088 problem = krb5_cc_initialize(authctxt->krb5_ctx, ccache,
89 authctxt->krb5_user);
Damien Miller964fed52001-09-25 12:58:23 +100090 if (problem)
91 goto out;
Damien Millerdb95e4e2002-02-13 16:56:44 +110092
93 restore_uid();
Damien Miller787b2ec2003-11-21 23:56:47 +110094
Damien Miller964fed52001-09-25 12:58:23 +100095 problem = krb5_verify_user(authctxt->krb5_ctx, authctxt->krb5_user,
Darren Tuckerec0943a2003-08-11 22:55:36 +100096 ccache, password, 1, NULL);
Damien Miller787b2ec2003-11-21 23:56:47 +110097
Damien Millerdb95e4e2002-02-13 16:56:44 +110098 temporarily_use_uid(authctxt->pw);
99
Damien Miller964fed52001-09-25 12:58:23 +1000100 if (problem)
101 goto out;
Darren Tuckerec217ad2003-11-22 12:11:06 +1100102
Darren Tuckerec0943a2003-08-11 22:55:36 +1000103 problem = krb5_cc_gen_new(authctxt->krb5_ctx, &krb5_fcc_ops,
104 &authctxt->krb5_fwd_ccache);
105 if (problem)
106 goto out;
107
108 problem = krb5_cc_copy_cache(authctxt->krb5_ctx, ccache,
109 authctxt->krb5_fwd_ccache);
110 krb5_cc_destroy(authctxt->krb5_ctx, ccache);
111 ccache = NULL;
112 if (problem)
113 goto out;
Damien Millerdb95e4e2002-02-13 16:56:44 +1100114
Damien Millerfd4c9ee2002-04-13 11:04:40 +1000115#else
116 problem = krb5_get_init_creds_password(authctxt->krb5_ctx, &creds,
117 authctxt->krb5_user, (char *)password, NULL, NULL, 0, NULL, NULL);
118 if (problem)
119 goto out;
120
121 problem = krb5_sname_to_principal(authctxt->krb5_ctx, NULL, NULL,
122 KRB5_NT_SRV_HST, &server);
123 if (problem)
124 goto out;
125
126 restore_uid();
127 problem = krb5_verify_init_creds(authctxt->krb5_ctx, &creds, server,
128 NULL, NULL, NULL);
129 krb5_free_principal(authctxt->krb5_ctx, server);
130 temporarily_use_uid(authctxt->pw);
131 if (problem)
132 goto out;
Damien Miller787b2ec2003-11-21 23:56:47 +1100133
Damien Millera8e06ce2003-11-21 23:48:55 +1100134 if (!krb5_kuserok(authctxt->krb5_ctx, authctxt->krb5_user,
Damien Millerfd4c9ee2002-04-13 11:04:40 +1000135 authctxt->pw->pw_name)) {
Ben Lindstrom5a6abda2002-06-09 19:41:48 +0000136 problem = -1;
Damien Millerfd4c9ee2002-04-13 11:04:40 +1000137 goto out;
Damien Millera8e06ce2003-11-21 23:48:55 +1100138 }
Damien Millerfd4c9ee2002-04-13 11:04:40 +1000139
Darren Tuckera916d142005-07-07 11:50:20 +1000140 problem = ssh_krb5_cc_gen(authctxt->krb5_ctx, &authctxt->krb5_fwd_ccache);
Damien Millerfd4c9ee2002-04-13 11:04:40 +1000141 if (problem)
142 goto out;
143
144 problem = krb5_cc_initialize(authctxt->krb5_ctx, authctxt->krb5_fwd_ccache,
145 authctxt->krb5_user);
146 if (problem)
147 goto out;
Damien Miller787b2ec2003-11-21 23:56:47 +1100148
Damien Millerfd4c9ee2002-04-13 11:04:40 +1000149 problem= krb5_cc_store_cred(authctxt->krb5_ctx, authctxt->krb5_fwd_ccache,
150 &creds);
151 if (problem)
152 goto out;
Damien Miller787b2ec2003-11-21 23:56:47 +1100153#endif
Damien Millerfd4c9ee2002-04-13 11:04:40 +1000154
Damien Miller964fed52001-09-25 12:58:23 +1000155 authctxt->krb5_ticket_file = (char *)krb5_cc_get_name(authctxt->krb5_ctx, authctxt->krb5_fwd_ccache);
Damien Millerdb95e4e2002-02-13 16:56:44 +1100156
Damien Miller9c870f92004-04-16 22:47:55 +1000157 len = strlen(authctxt->krb5_ticket_file) + 6;
158 authctxt->krb5_ccname = xmalloc(len);
159 snprintf(authctxt->krb5_ccname, len, "FILE:%s",
160 authctxt->krb5_ticket_file);
161
Darren Tucker5614d8f2004-09-11 23:32:09 +1000162#ifdef USE_PAM
163 if (options.use_pam)
164 do_pam_putenv("KRB5CCNAME", authctxt->krb5_ccname);
165#endif
166
Damien Miller964fed52001-09-25 12:58:23 +1000167 out:
168 restore_uid();
Damien Millerdb95e4e2002-02-13 16:56:44 +1100169
Damien Miller964fed52001-09-25 12:58:23 +1000170 if (problem) {
Darren Tuckerec0943a2003-08-11 22:55:36 +1000171 if (ccache)
172 krb5_cc_destroy(authctxt->krb5_ctx, ccache);
173
Damien Millerfd4c9ee2002-04-13 11:04:40 +1000174 if (authctxt->krb5_ctx != NULL && problem!=-1)
Ben Lindstromb8550282002-02-26 17:46:11 +0000175 debug("Kerberos password authentication failed: %s",
176 krb5_get_err_text(authctxt->krb5_ctx, problem));
177 else
178 debug("Kerberos password authentication failed: %d",
179 problem);
Damien Millerdb95e4e2002-02-13 16:56:44 +1100180
Damien Miller964fed52001-09-25 12:58:23 +1000181 krb5_cleanup_proc(authctxt);
Damien Millerdb95e4e2002-02-13 16:56:44 +1100182
Damien Miller964fed52001-09-25 12:58:23 +1000183 if (options.kerberos_or_local_passwd)
184 return (-1);
185 else
186 return (0);
187 }
Darren Tuckerf4732f62005-11-22 19:42:42 +1100188 return (authctxt->valid ? 1 : 0);
Damien Miller964fed52001-09-25 12:58:23 +1000189}
190
191void
Darren Tucker3e33cec2003-10-02 16:12:36 +1000192krb5_cleanup_proc(Authctxt *authctxt)
Damien Miller964fed52001-09-25 12:58:23 +1000193{
Damien Miller964fed52001-09-25 12:58:23 +1000194 debug("krb5_cleanup_proc called");
195 if (authctxt->krb5_fwd_ccache) {
196 krb5_cc_destroy(authctxt->krb5_ctx, authctxt->krb5_fwd_ccache);
197 authctxt->krb5_fwd_ccache = NULL;
198 }
199 if (authctxt->krb5_user) {
200 krb5_free_principal(authctxt->krb5_ctx, authctxt->krb5_user);
201 authctxt->krb5_user = NULL;
202 }
Damien Miller964fed52001-09-25 12:58:23 +1000203 if (authctxt->krb5_ctx) {
204 krb5_free_context(authctxt->krb5_ctx);
205 authctxt->krb5_ctx = NULL;
206 }
207}
208
Darren Tuckera916d142005-07-07 11:50:20 +1000209#ifndef HEIMDAL
210krb5_error_code
211ssh_krb5_cc_gen(krb5_context ctx, krb5_ccache *ccache) {
212 int tmpfd, ret;
213 char ccname[40];
214 mode_t old_umask;
215
216 ret = snprintf(ccname, sizeof(ccname),
217 "FILE:/tmp/krb5cc_%d_XXXXXXXXXX", geteuid());
Darren Tucker618db972005-11-10 14:43:11 +1100218 if (ret < 0 || (size_t)ret >= sizeof(ccname))
Darren Tuckera83f2612005-07-07 20:09:35 +1000219 return ENOMEM;
Darren Tuckera916d142005-07-07 11:50:20 +1000220
221 old_umask = umask(0177);
222 tmpfd = mkstemp(ccname + strlen("FILE:"));
223 umask(old_umask);
224 if (tmpfd == -1) {
225 logit("mkstemp(): %.100s", strerror(errno));
226 return errno;
227 }
228
229 if (fchmod(tmpfd,S_IRUSR | S_IWUSR) == -1) {
230 logit("fchmod(): %.100s", strerror(errno));
231 close(tmpfd);
232 return errno;
233 }
234 close(tmpfd);
235
236 return (krb5_cc_resolve(ctx, ccname, ccache));
237}
238#endif /* !HEIMDAL */
Damien Miller964fed52001-09-25 12:58:23 +1000239#endif /* KRB5 */