blob: 8beacc0d4680080f50c8316c31dd6a156964ac32 [file] [log] [blame]
Darren Tucker43ff44e2006-05-06 18:40:53 +10001/* $OpenBSD: auth-krb5.c,v 1.18 2006/05/06 08:35:40 dtucker Exp $ */
Damien Miller964fed52001-09-25 12:58:23 +10002/*
3 * Kerberos v5 authentication and ticket-passing routines.
Ben Lindstrom6328ab32002-03-22 02:54:23 +00004 *
Damien Miller964fed52001-09-25 12:58:23 +10005 * $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 +10006 */
Ben Lindstromeacc71b2002-03-22 01:22:27 +00007/*
8 * Copyright (c) 2002 Daniel Kouril. All rights reserved.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
20 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
21 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
22 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
23 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
24 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
28 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 */
Damien Miller964fed52001-09-25 12:58:23 +100030
31#include "includes.h"
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
Darren Tucker341dae52006-07-13 08:45:14 +100043#include <errno.h>
Damien Miller964fed52001-09-25 12:58:23 +100044#include <krb5.h>
45
46extern ServerOptions options;
47
48static int
49krb5_init(void *context)
50{
51 Authctxt *authctxt = (Authctxt *)context;
52 krb5_error_code problem;
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);
Damien Miller964fed52001-09-25 12:58:23 +100058 }
Damien Miller964fed52001-09-25 12:58:23 +100059 return (0);
60}
61
Damien Miller964fed52001-09-25 12:58:23 +100062int
63auth_krb5_password(Authctxt *authctxt, const char *password)
64{
Damien Millerfd4c9ee2002-04-13 11:04:40 +100065#ifndef HEIMDAL
66 krb5_creds creds;
67 krb5_principal server;
Damien Miller787b2ec2003-11-21 23:56:47 +110068#endif
Damien Miller964fed52001-09-25 12:58:23 +100069 krb5_error_code problem;
Darren Tuckerec0943a2003-08-11 22:55:36 +100070 krb5_ccache ccache = NULL;
Damien Miller9c870f92004-04-16 22:47:55 +100071 int len;
Damien Millerdb95e4e2002-02-13 16:56:44 +110072
Damien Miller964fed52001-09-25 12:58:23 +100073 temporarily_use_uid(authctxt->pw);
Damien Millerdb95e4e2002-02-13 16:56:44 +110074
Damien Miller964fed52001-09-25 12:58:23 +100075 problem = krb5_init(authctxt);
76 if (problem)
77 goto out;
Damien Millerdb95e4e2002-02-13 16:56:44 +110078
Damien Miller964fed52001-09-25 12:58:23 +100079 problem = krb5_parse_name(authctxt->krb5_ctx, authctxt->pw->pw_name,
80 &authctxt->krb5_user);
81 if (problem)
82 goto out;
Damien Millerdb95e4e2002-02-13 16:56:44 +110083
Damien Millerfd4c9ee2002-04-13 11:04:40 +100084#ifdef HEIMDAL
Darren Tuckerec0943a2003-08-11 22:55:36 +100085 problem = krb5_cc_gen_new(authctxt->krb5_ctx, &krb5_mcc_ops, &ccache);
Damien Miller964fed52001-09-25 12:58:23 +100086 if (problem)
87 goto out;
Damien Millerdb95e4e2002-02-13 16:56:44 +110088
Darren Tuckerec0943a2003-08-11 22:55:36 +100089 problem = krb5_cc_initialize(authctxt->krb5_ctx, ccache,
90 authctxt->krb5_user);
Damien Miller964fed52001-09-25 12:58:23 +100091 if (problem)
92 goto out;
Damien Millerdb95e4e2002-02-13 16:56:44 +110093
94 restore_uid();
Damien Miller787b2ec2003-11-21 23:56:47 +110095
Damien Miller964fed52001-09-25 12:58:23 +100096 problem = krb5_verify_user(authctxt->krb5_ctx, authctxt->krb5_user,
Darren Tuckerec0943a2003-08-11 22:55:36 +100097 ccache, password, 1, NULL);
Damien Miller787b2ec2003-11-21 23:56:47 +110098
Damien Millerdb95e4e2002-02-13 16:56:44 +110099 temporarily_use_uid(authctxt->pw);
100
Damien Miller964fed52001-09-25 12:58:23 +1000101 if (problem)
102 goto out;
Darren Tuckerec217ad2003-11-22 12:11:06 +1100103
Darren Tuckerec0943a2003-08-11 22:55:36 +1000104 problem = krb5_cc_gen_new(authctxt->krb5_ctx, &krb5_fcc_ops,
105 &authctxt->krb5_fwd_ccache);
106 if (problem)
107 goto out;
108
109 problem = krb5_cc_copy_cache(authctxt->krb5_ctx, ccache,
110 authctxt->krb5_fwd_ccache);
111 krb5_cc_destroy(authctxt->krb5_ctx, ccache);
112 ccache = NULL;
113 if (problem)
114 goto out;
Damien Millerdb95e4e2002-02-13 16:56:44 +1100115
Damien Millerfd4c9ee2002-04-13 11:04:40 +1000116#else
117 problem = krb5_get_init_creds_password(authctxt->krb5_ctx, &creds,
118 authctxt->krb5_user, (char *)password, NULL, NULL, 0, NULL, NULL);
119 if (problem)
120 goto out;
121
122 problem = krb5_sname_to_principal(authctxt->krb5_ctx, NULL, NULL,
123 KRB5_NT_SRV_HST, &server);
124 if (problem)
125 goto out;
126
127 restore_uid();
128 problem = krb5_verify_init_creds(authctxt->krb5_ctx, &creds, server,
129 NULL, NULL, NULL);
130 krb5_free_principal(authctxt->krb5_ctx, server);
131 temporarily_use_uid(authctxt->pw);
132 if (problem)
133 goto out;
Damien Miller787b2ec2003-11-21 23:56:47 +1100134
Damien Millera8e06ce2003-11-21 23:48:55 +1100135 if (!krb5_kuserok(authctxt->krb5_ctx, authctxt->krb5_user,
Damien Millerfd4c9ee2002-04-13 11:04:40 +1000136 authctxt->pw->pw_name)) {
Ben Lindstrom5a6abda2002-06-09 19:41:48 +0000137 problem = -1;
Damien Millerfd4c9ee2002-04-13 11:04:40 +1000138 goto out;
Damien Millera8e06ce2003-11-21 23:48:55 +1100139 }
Damien Millerfd4c9ee2002-04-13 11:04:40 +1000140
Darren Tuckera916d142005-07-07 11:50:20 +1000141 problem = ssh_krb5_cc_gen(authctxt->krb5_ctx, &authctxt->krb5_fwd_ccache);
Damien Millerfd4c9ee2002-04-13 11:04:40 +1000142 if (problem)
143 goto out;
144
145 problem = krb5_cc_initialize(authctxt->krb5_ctx, authctxt->krb5_fwd_ccache,
146 authctxt->krb5_user);
147 if (problem)
148 goto out;
Damien Miller787b2ec2003-11-21 23:56:47 +1100149
Damien Millerfd4c9ee2002-04-13 11:04:40 +1000150 problem= krb5_cc_store_cred(authctxt->krb5_ctx, authctxt->krb5_fwd_ccache,
151 &creds);
152 if (problem)
153 goto out;
Damien Miller787b2ec2003-11-21 23:56:47 +1100154#endif
Damien Millerfd4c9ee2002-04-13 11:04:40 +1000155
Damien Miller964fed52001-09-25 12:58:23 +1000156 authctxt->krb5_ticket_file = (char *)krb5_cc_get_name(authctxt->krb5_ctx, authctxt->krb5_fwd_ccache);
Damien Millerdb95e4e2002-02-13 16:56:44 +1100157
Damien Miller9c870f92004-04-16 22:47:55 +1000158 len = strlen(authctxt->krb5_ticket_file) + 6;
159 authctxt->krb5_ccname = xmalloc(len);
160 snprintf(authctxt->krb5_ccname, len, "FILE:%s",
161 authctxt->krb5_ticket_file);
162
Darren Tucker5614d8f2004-09-11 23:32:09 +1000163#ifdef USE_PAM
164 if (options.use_pam)
165 do_pam_putenv("KRB5CCNAME", authctxt->krb5_ccname);
166#endif
167
Damien Miller964fed52001-09-25 12:58:23 +1000168 out:
169 restore_uid();
Damien Millerdb95e4e2002-02-13 16:56:44 +1100170
Damien Miller964fed52001-09-25 12:58:23 +1000171 if (problem) {
Darren Tuckerec0943a2003-08-11 22:55:36 +1000172 if (ccache)
173 krb5_cc_destroy(authctxt->krb5_ctx, ccache);
174
Damien Millerfd4c9ee2002-04-13 11:04:40 +1000175 if (authctxt->krb5_ctx != NULL && problem!=-1)
Ben Lindstromb8550282002-02-26 17:46:11 +0000176 debug("Kerberos password authentication failed: %s",
177 krb5_get_err_text(authctxt->krb5_ctx, problem));
178 else
179 debug("Kerberos password authentication failed: %d",
180 problem);
Damien Millerdb95e4e2002-02-13 16:56:44 +1100181
Damien Miller964fed52001-09-25 12:58:23 +1000182 krb5_cleanup_proc(authctxt);
Damien Millerdb95e4e2002-02-13 16:56:44 +1100183
Damien Miller964fed52001-09-25 12:58:23 +1000184 if (options.kerberos_or_local_passwd)
185 return (-1);
186 else
187 return (0);
188 }
Darren Tuckerf4732f62005-11-22 19:42:42 +1100189 return (authctxt->valid ? 1 : 0);
Damien Miller964fed52001-09-25 12:58:23 +1000190}
191
192void
Darren Tucker3e33cec2003-10-02 16:12:36 +1000193krb5_cleanup_proc(Authctxt *authctxt)
Damien Miller964fed52001-09-25 12:58:23 +1000194{
Damien Miller964fed52001-09-25 12:58:23 +1000195 debug("krb5_cleanup_proc called");
196 if (authctxt->krb5_fwd_ccache) {
197 krb5_cc_destroy(authctxt->krb5_ctx, authctxt->krb5_fwd_ccache);
198 authctxt->krb5_fwd_ccache = NULL;
199 }
200 if (authctxt->krb5_user) {
201 krb5_free_principal(authctxt->krb5_ctx, authctxt->krb5_user);
202 authctxt->krb5_user = NULL;
203 }
Damien Miller964fed52001-09-25 12:58:23 +1000204 if (authctxt->krb5_ctx) {
205 krb5_free_context(authctxt->krb5_ctx);
206 authctxt->krb5_ctx = NULL;
207 }
208}
209
Darren Tuckera916d142005-07-07 11:50:20 +1000210#ifndef HEIMDAL
211krb5_error_code
212ssh_krb5_cc_gen(krb5_context ctx, krb5_ccache *ccache) {
213 int tmpfd, ret;
214 char ccname[40];
215 mode_t old_umask;
216
217 ret = snprintf(ccname, sizeof(ccname),
218 "FILE:/tmp/krb5cc_%d_XXXXXXXXXX", geteuid());
Darren Tucker618db972005-11-10 14:43:11 +1100219 if (ret < 0 || (size_t)ret >= sizeof(ccname))
Darren Tuckera83f2612005-07-07 20:09:35 +1000220 return ENOMEM;
Darren Tuckera916d142005-07-07 11:50:20 +1000221
222 old_umask = umask(0177);
223 tmpfd = mkstemp(ccname + strlen("FILE:"));
224 umask(old_umask);
225 if (tmpfd == -1) {
226 logit("mkstemp(): %.100s", strerror(errno));
227 return errno;
228 }
229
230 if (fchmod(tmpfd,S_IRUSR | S_IWUSR) == -1) {
231 logit("fchmod(): %.100s", strerror(errno));
232 close(tmpfd);
233 return errno;
234 }
235 close(tmpfd);
236
237 return (krb5_cc_resolve(ctx, ccname, ccache));
238}
239#endif /* !HEIMDAL */
Damien Miller964fed52001-09-25 12:58:23 +1000240#endif /* KRB5 */