auth-krb5.c revision 1.1.1.3 
1/* $OpenBSD: auth-krb5.c,v 1.20 2013/07/20 01:55:13 djm Exp $ */
2/*
3 *    Kerberos v5 authentication and ticket-passing routines.
4 *
5 * $FreeBSD: src/crypto/openssh/auth-krb5.c,v 1.6 2001/02/13 16:58:04 assar Exp $
6 */
7/*
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 */
30
31#include <sys/types.h>
32#include <pwd.h>
33#include <stdarg.h>
34
35#include "xmalloc.h"
36#include "ssh.h"
37#include "ssh1.h"
38#include "packet.h"
39#include "log.h"
40#include "buffer.h"
41#include "servconf.h"
42#include "uidswap.h"
43#include "key.h"
44#include "hostfile.h"
45#include "auth.h"
46
47#ifdef KRB5
48#include <krb5.h>
49
50extern ServerOptions	 options;
51
52static int
53krb5_init(void *context)
54{
55	Authctxt *authctxt = (Authctxt *)context;
56	krb5_error_code problem;
57
58	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	return (0);
65}
66
67int
68auth_krb5_password(Authctxt *authctxt, const char *password)
69{
70	krb5_error_code problem;
71	krb5_ccache ccache = NULL;
72	const char *errmsg;
73
74	temporarily_use_uid(authctxt->pw);
75
76	problem = krb5_init(authctxt);
77	if (problem)
78		goto out;
79
80	problem = krb5_parse_name(authctxt->krb5_ctx, authctxt->pw->pw_name,
81		    &authctxt->krb5_user);
82	if (problem)
83		goto out;
84
85	problem = krb5_cc_new_unique(authctxt->krb5_ctx,
86	     krb5_mcc_ops.prefix, NULL, &ccache);
87	if (problem)
88		goto out;
89
90	problem = krb5_cc_initialize(authctxt->krb5_ctx, ccache,
91		authctxt->krb5_user);
92	if (problem)
93		goto out;
94
95	restore_uid();
96
97	problem = krb5_verify_user(authctxt->krb5_ctx, authctxt->krb5_user,
98	    ccache, password, 1, NULL);
99
100	temporarily_use_uid(authctxt->pw);
101
102	if (problem)
103		goto out;
104
105	problem = krb5_cc_new_unique(authctxt->krb5_ctx,
106	     krb5_fcc_ops.prefix, NULL, &authctxt->krb5_fwd_ccache);
107	if (problem)
108		goto out;
109
110	problem = krb5_cc_copy_cache(authctxt->krb5_ctx, ccache,
111	    authctxt->krb5_fwd_ccache);
112	krb5_cc_destroy(authctxt->krb5_ctx, ccache);
113	ccache = NULL;
114	if (problem)
115		goto out;
116
117	authctxt->krb5_ticket_file = (char *)krb5_cc_get_name(authctxt->krb5_ctx,
118	    authctxt->krb5_fwd_ccache);
119
120 out:
121	restore_uid();
122
123	if (problem) {
124		if (ccache)
125			krb5_cc_destroy(authctxt->krb5_ctx, ccache);
126
127		if (authctxt->krb5_ctx != NULL) {
128			errmsg = krb5_get_error_message(authctxt->krb5_ctx,
129			    problem);
130			debug("Kerberos password authentication failed: %s",
131			    errmsg);
132			krb5_free_error_message(authctxt->krb5_ctx, errmsg);
133		} else
134			debug("Kerberos password authentication failed: %d",
135			    problem);
136
137		krb5_cleanup_proc(authctxt);
138
139		if (options.kerberos_or_local_passwd)
140			return (-1);
141		else
142			return (0);
143	}
144	return (authctxt->valid ? 1 : 0);
145}
146
147void
148krb5_cleanup_proc(Authctxt *authctxt)
149{
150	debug("krb5_cleanup_proc called");
151	if (authctxt->krb5_fwd_ccache) {
152		krb5_cc_destroy(authctxt->krb5_ctx, authctxt->krb5_fwd_ccache);
153		authctxt->krb5_fwd_ccache = NULL;
154	}
155	if (authctxt->krb5_user) {
156		krb5_free_principal(authctxt->krb5_ctx, authctxt->krb5_user);
157		authctxt->krb5_user = NULL;
158	}
159	if (authctxt->krb5_ctx) {
160		krb5_free_context(authctxt->krb5_ctx);
161		authctxt->krb5_ctx = NULL;
162	}
163}
164
165#endif /* KRB5 */
166