1/*
2 * Copyright (c) 1997 - 2008 Kungliga Tekniska Högskolan
3 * (Royal Institute of Technology, Stockholm, Sweden).
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 *
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 *
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 *
17 * 3. Neither the name of the Institute nor the names of its contributors
18 *    may be used to endorse or promote products derived from this software
19 *    without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34#include "krb5_locl.h"
35
36KRB5_LIB_FUNCTION void KRB5_LIB_CALL
37krb5_verify_init_creds_opt_init(krb5_verify_init_creds_opt *options)
38{
39    memset (options, 0, sizeof(*options));
40}
41
42KRB5_LIB_FUNCTION void KRB5_LIB_CALL
43krb5_verify_init_creds_opt_set_ap_req_nofail(krb5_verify_init_creds_opt *options,
44					     int ap_req_nofail)
45{
46    options->flags |= KRB5_VERIFY_INIT_CREDS_OPT_AP_REQ_NOFAIL;
47    options->ap_req_nofail = ap_req_nofail;
48}
49
50/*
51 *
52 */
53
54static krb5_boolean
55fail_verify_is_ok (krb5_context context,
56		   krb5_verify_init_creds_opt *options)
57{
58    if ((options->flags & KRB5_VERIFY_INIT_CREDS_OPT_AP_REQ_NOFAIL
59	 && options->ap_req_nofail != 0)
60	|| krb5_config_get_bool (context,
61				 NULL,
62				 "libdefaults",
63				 "verify_ap_req_nofail",
64				 NULL))
65	return FALSE;
66    else
67	return TRUE;
68}
69
70KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
71krb5_verify_init_creds(krb5_context context,
72		       krb5_creds *creds,
73		       krb5_principal ap_req_server,
74		       krb5_keytab ap_req_keytab,
75		       krb5_ccache *ccache,
76		       krb5_verify_init_creds_opt *options)
77{
78    krb5_error_code ret;
79    krb5_data req;
80    krb5_ccache local_ccache = NULL;
81    krb5_creds *new_creds = NULL;
82    krb5_auth_context auth_context = NULL;
83    krb5_principal server = NULL;
84    krb5_keytab keytab = NULL;
85
86    krb5_data_zero (&req);
87
88    if (ap_req_server == NULL) {
89	char local_hostname[MAXHOSTNAMELEN];
90
91	if (gethostname (local_hostname, sizeof(local_hostname)) < 0) {
92	    ret = errno;
93	    krb5_set_error_message (context, ret, "gethostname: %s",
94				    strerror(ret));
95	    return ret;
96	}
97
98	ret = krb5_sname_to_principal (context,
99				       local_hostname,
100				       "host",
101				       KRB5_NT_SRV_HST,
102				       &server);
103	if (ret)
104	    goto cleanup;
105    } else
106	server = ap_req_server;
107
108    if (ap_req_keytab == NULL) {
109	ret = krb5_kt_default (context, &keytab);
110	if (ret)
111	    goto cleanup;
112    } else
113	keytab = ap_req_keytab;
114
115    if (ccache && *ccache)
116	local_ccache = *ccache;
117    else {
118	ret = krb5_cc_new_unique(context, krb5_cc_type_memory,
119				 NULL, &local_ccache);
120	if (ret)
121	    goto cleanup;
122	ret = krb5_cc_initialize (context,
123				  local_ccache,
124				  creds->client);
125	if (ret)
126	    goto cleanup;
127	ret = krb5_cc_store_cred (context,
128				  local_ccache,
129				  creds);
130	if (ret)
131	    goto cleanup;
132    }
133
134    if (!krb5_principal_compare (context, server, creds->server)) {
135	krb5_creds match_cred;
136
137	memset (&match_cred, 0, sizeof(match_cred));
138
139	match_cred.client = creds->client;
140	match_cred.server = server;
141
142	ret = krb5_get_credentials (context,
143				    0,
144				    local_ccache,
145				    &match_cred,
146				    &new_creds);
147	if (ret) {
148	    if (fail_verify_is_ok (context, options))
149		ret = 0;
150	    goto cleanup;
151	}
152	creds = new_creds;
153    }
154
155    ret = krb5_mk_req_extended (context,
156				&auth_context,
157				0,
158				NULL,
159				creds,
160				&req);
161
162    krb5_auth_con_free (context, auth_context);
163    auth_context = NULL;
164
165    if (ret)
166	goto cleanup;
167
168    ret = krb5_rd_req (context,
169		       &auth_context,
170		       &req,
171		       server,
172		       keytab,
173		       0,
174		       NULL);
175
176    if (ret == KRB5_KT_NOTFOUND && fail_verify_is_ok (context, options))
177	ret = 0;
178cleanup:
179    if (auth_context)
180	krb5_auth_con_free (context, auth_context);
181    krb5_data_free (&req);
182    if (new_creds != NULL)
183	krb5_free_creds (context, new_creds);
184    if (ap_req_server == NULL && server)
185	krb5_free_principal (context, server);
186    if (ap_req_keytab == NULL && keytab)
187	krb5_kt_close (context, keytab);
188    if (local_ccache != NULL
189	&&
190	(ccache == NULL
191	 || (ret != 0 && *ccache == NULL)))
192	krb5_cc_destroy (context, local_ccache);
193
194    if (ret == 0 && ccache != NULL && *ccache == NULL)
195	*ccache = local_ccache;
196
197    return ret;
198}
199
200/**
201 * Validate the newly fetch credential, see also krb5_verify_init_creds().
202 *
203 * @param context a Kerberos 5 context
204 * @param creds the credentials to verify
205 * @param client the client name to match up
206 * @param ccache the credential cache to use
207 * @param service a service name to use, used with
208 *        krb5_sname_to_principal() to build a hostname to use to
209 *        verify.
210 *
211 * @ingroup krb5_ccache
212 */
213
214KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
215krb5_get_validated_creds(krb5_context context,
216			 krb5_creds *creds,
217			 krb5_principal client,
218			 krb5_ccache ccache,
219			 char *service)
220{
221    krb5_verify_init_creds_opt vopt;
222    krb5_principal server;
223    krb5_error_code ret;
224
225    if (krb5_principal_compare(context, creds->client, client) != TRUE) {
226	krb5_set_error_message(context, KRB5_PRINC_NOMATCH,
227			       N_("Validation credentials and client "
228				  "doesn't match", ""));
229	return KRB5_PRINC_NOMATCH;
230    }
231
232    ret = krb5_sname_to_principal (context, NULL, service,
233				   KRB5_NT_SRV_HST, &server);
234    if(ret)
235	return ret;
236
237    krb5_verify_init_creds_opt_init(&vopt);
238
239    ret = krb5_verify_init_creds(context, creds, server, NULL, NULL, &vopt);
240    krb5_free_principal(context, server);
241
242    return ret;
243}
244