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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"
Damien Millera8e06ce2003-11-21 23:48:55 +110031RCSID("$OpenBSD: auth-krb5.c,v 1.15 2003/11/21 11:57:02 djm 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);
Ben Lindstroma8104b52004-04-07 04:16:11 +000057#ifdef KRB5_INIT_ETS
Damien Miller964fed52001-09-25 12:58:23 +100058 krb5_init_ets(authctxt->krb5_ctx);
Ben Lindstroma8104b52004-04-07 04:16:11 +000059#endif
Damien Miller964fed52001-09-25 12:58:23 +100060 }
Damien Miller964fed52001-09-25 12:58:23 +100061 return (0);
62}
63
Damien Miller964fed52001-09-25 12:58:23 +100064int
65auth_krb5_password(Authctxt *authctxt, const char *password)
66{
Damien Millerfd4c9ee2002-04-13 11:04:40 +100067#ifndef HEIMDAL
68 krb5_creds creds;
69 krb5_principal server;
70 char ccname[40];
71 int tmpfd;
Darren Tucker06696932004-08-14 23:55:37 +100072 mode_t old_umask;
Damien Miller787b2ec2003-11-21 23:56:47 +110073#endif
Damien Miller964fed52001-09-25 12:58:23 +100074 krb5_error_code problem;
Darren Tuckerec0943a2003-08-11 22:55:36 +100075 krb5_ccache ccache = NULL;
Damien Miller9c870f92004-04-16 22:47:55 +100076 int len;
Damien Millerdb95e4e2002-02-13 16:56:44 +110077
Damien Miller3e3b5142003-11-17 21:13:40 +110078 if (!authctxt->valid)
Damien Miller964fed52001-09-25 12:58:23 +100079 return (0);
Damien Millerdb95e4e2002-02-13 16:56:44 +110080
Damien Miller964fed52001-09-25 12:58:23 +100081 temporarily_use_uid(authctxt->pw);
Damien Millerdb95e4e2002-02-13 16:56:44 +110082
Damien Miller964fed52001-09-25 12:58:23 +100083 problem = krb5_init(authctxt);
84 if (problem)
85 goto out;
Damien Millerdb95e4e2002-02-13 16:56:44 +110086
Damien Miller964fed52001-09-25 12:58:23 +100087 problem = krb5_parse_name(authctxt->krb5_ctx, authctxt->pw->pw_name,
88 &authctxt->krb5_user);
89 if (problem)
90 goto out;
Damien Millerdb95e4e2002-02-13 16:56:44 +110091
Damien Millerfd4c9ee2002-04-13 11:04:40 +100092#ifdef HEIMDAL
Darren Tuckerec0943a2003-08-11 22:55:36 +100093 problem = krb5_cc_gen_new(authctxt->krb5_ctx, &krb5_mcc_ops, &ccache);
Damien Miller964fed52001-09-25 12:58:23 +100094 if (problem)
95 goto out;
Damien Millerdb95e4e2002-02-13 16:56:44 +110096
Darren Tuckerec0943a2003-08-11 22:55:36 +100097 problem = krb5_cc_initialize(authctxt->krb5_ctx, ccache,
98 authctxt->krb5_user);
Damien Miller964fed52001-09-25 12:58:23 +100099 if (problem)
100 goto out;
Damien Millerdb95e4e2002-02-13 16:56:44 +1100101
102 restore_uid();
Damien Miller787b2ec2003-11-21 23:56:47 +1100103
Damien Miller964fed52001-09-25 12:58:23 +1000104 problem = krb5_verify_user(authctxt->krb5_ctx, authctxt->krb5_user,
Darren Tuckerec0943a2003-08-11 22:55:36 +1000105 ccache, password, 1, NULL);
Damien Miller787b2ec2003-11-21 23:56:47 +1100106
Damien Millerdb95e4e2002-02-13 16:56:44 +1100107 temporarily_use_uid(authctxt->pw);
108
Damien Miller964fed52001-09-25 12:58:23 +1000109 if (problem)
110 goto out;
Darren Tuckerec217ad2003-11-22 12:11:06 +1100111
Darren Tuckerec0943a2003-08-11 22:55:36 +1000112 problem = krb5_cc_gen_new(authctxt->krb5_ctx, &krb5_fcc_ops,
113 &authctxt->krb5_fwd_ccache);
114 if (problem)
115 goto out;
116
117 problem = krb5_cc_copy_cache(authctxt->krb5_ctx, ccache,
118 authctxt->krb5_fwd_ccache);
119 krb5_cc_destroy(authctxt->krb5_ctx, ccache);
120 ccache = NULL;
121 if (problem)
122 goto out;
Damien Millerdb95e4e2002-02-13 16:56:44 +1100123
Damien Millerfd4c9ee2002-04-13 11:04:40 +1000124#else
125 problem = krb5_get_init_creds_password(authctxt->krb5_ctx, &creds,
126 authctxt->krb5_user, (char *)password, NULL, NULL, 0, NULL, NULL);
127 if (problem)
128 goto out;
129
130 problem = krb5_sname_to_principal(authctxt->krb5_ctx, NULL, NULL,
131 KRB5_NT_SRV_HST, &server);
132 if (problem)
133 goto out;
134
135 restore_uid();
136 problem = krb5_verify_init_creds(authctxt->krb5_ctx, &creds, server,
137 NULL, NULL, NULL);
138 krb5_free_principal(authctxt->krb5_ctx, server);
139 temporarily_use_uid(authctxt->pw);
140 if (problem)
141 goto out;
Damien Miller787b2ec2003-11-21 23:56:47 +1100142
Damien Millera8e06ce2003-11-21 23:48:55 +1100143 if (!krb5_kuserok(authctxt->krb5_ctx, authctxt->krb5_user,
Damien Millerfd4c9ee2002-04-13 11:04:40 +1000144 authctxt->pw->pw_name)) {
Ben Lindstrom5a6abda2002-06-09 19:41:48 +0000145 problem = -1;
Damien Millerfd4c9ee2002-04-13 11:04:40 +1000146 goto out;
Damien Millera8e06ce2003-11-21 23:48:55 +1100147 }
Damien Millerfd4c9ee2002-04-13 11:04:40 +1000148
149 snprintf(ccname,sizeof(ccname),"FILE:/tmp/krb5cc_%d_XXXXXX",geteuid());
Damien Miller787b2ec2003-11-21 23:56:47 +1100150
Darren Tucker06696932004-08-14 23:55:37 +1000151 old_umask = umask(0177);
152 tmpfd = mkstemp(ccname + strlen("FILE:"));
153 umask(old_umask);
154 if (tmpfd == -1) {
Damien Miller996acd22003-04-09 20:59:48 +1000155 logit("mkstemp(): %.100s", strerror(errno));
Damien Millerfd4c9ee2002-04-13 11:04:40 +1000156 problem = errno;
157 goto out;
158 }
Damien Miller787b2ec2003-11-21 23:56:47 +1100159
Damien Millerfd4c9ee2002-04-13 11:04:40 +1000160 if (fchmod(tmpfd,S_IRUSR | S_IWUSR) == -1) {
Damien Miller996acd22003-04-09 20:59:48 +1000161 logit("fchmod(): %.100s", strerror(errno));
Damien Millerfd4c9ee2002-04-13 11:04:40 +1000162 close(tmpfd);
163 problem = errno;
164 goto out;
165 }
166 close(tmpfd);
167
168 problem = krb5_cc_resolve(authctxt->krb5_ctx, ccname, &authctxt->krb5_fwd_ccache);
169 if (problem)
170 goto out;
171
172 problem = krb5_cc_initialize(authctxt->krb5_ctx, authctxt->krb5_fwd_ccache,
173 authctxt->krb5_user);
174 if (problem)
175 goto out;
Damien Miller787b2ec2003-11-21 23:56:47 +1100176
Damien Millerfd4c9ee2002-04-13 11:04:40 +1000177 problem= krb5_cc_store_cred(authctxt->krb5_ctx, authctxt->krb5_fwd_ccache,
178 &creds);
179 if (problem)
180 goto out;
Damien Miller787b2ec2003-11-21 23:56:47 +1100181#endif
Damien Millerfd4c9ee2002-04-13 11:04:40 +1000182
Damien Miller964fed52001-09-25 12:58:23 +1000183 authctxt->krb5_ticket_file = (char *)krb5_cc_get_name(authctxt->krb5_ctx, authctxt->krb5_fwd_ccache);
Damien Millerdb95e4e2002-02-13 16:56:44 +1100184
Damien Miller9c870f92004-04-16 22:47:55 +1000185 len = strlen(authctxt->krb5_ticket_file) + 6;
186 authctxt->krb5_ccname = xmalloc(len);
187 snprintf(authctxt->krb5_ccname, len, "FILE:%s",
188 authctxt->krb5_ticket_file);
189
Damien Miller964fed52001-09-25 12:58:23 +1000190 out:
191 restore_uid();
Damien Millerdb95e4e2002-02-13 16:56:44 +1100192
Damien Miller964fed52001-09-25 12:58:23 +1000193 if (problem) {
Darren Tuckerec0943a2003-08-11 22:55:36 +1000194 if (ccache)
195 krb5_cc_destroy(authctxt->krb5_ctx, ccache);
196
Damien Millerfd4c9ee2002-04-13 11:04:40 +1000197 if (authctxt->krb5_ctx != NULL && problem!=-1)
Ben Lindstromb8550282002-02-26 17:46:11 +0000198 debug("Kerberos password authentication failed: %s",
199 krb5_get_err_text(authctxt->krb5_ctx, problem));
200 else
201 debug("Kerberos password authentication failed: %d",
202 problem);
Damien Millerdb95e4e2002-02-13 16:56:44 +1100203
Damien Miller964fed52001-09-25 12:58:23 +1000204 krb5_cleanup_proc(authctxt);
Damien Millerdb95e4e2002-02-13 16:56:44 +1100205
Damien Miller964fed52001-09-25 12:58:23 +1000206 if (options.kerberos_or_local_passwd)
207 return (-1);
208 else
209 return (0);
210 }
211 return (1);
212}
213
214void
Darren Tucker3e33cec2003-10-02 16:12:36 +1000215krb5_cleanup_proc(Authctxt *authctxt)
Damien Miller964fed52001-09-25 12:58:23 +1000216{
Damien Miller964fed52001-09-25 12:58:23 +1000217 debug("krb5_cleanup_proc called");
218 if (authctxt->krb5_fwd_ccache) {
219 krb5_cc_destroy(authctxt->krb5_ctx, authctxt->krb5_fwd_ccache);
220 authctxt->krb5_fwd_ccache = NULL;
221 }
222 if (authctxt->krb5_user) {
223 krb5_free_principal(authctxt->krb5_ctx, authctxt->krb5_user);
224 authctxt->krb5_user = NULL;
225 }
Damien Miller964fed52001-09-25 12:58:23 +1000226 if (authctxt->krb5_ctx) {
227 krb5_free_context(authctxt->krb5_ctx);
228 authctxt->krb5_ctx = NULL;
229 }
230}
231
232#endif /* KRB5 */