xref: /freebsd/crypto/heimdal/lib/krb5/verify_init.c (revision a7623790fb345e6dc986dfd31df0ace115e6f2e4)
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 
36 KRB5_LIB_FUNCTION void KRB5_LIB_CALL
37 krb5_verify_init_creds_opt_init(krb5_verify_init_creds_opt *options)
38 {
39     memset (options, 0, sizeof(*options));
40 }
41 
42 KRB5_LIB_FUNCTION void KRB5_LIB_CALL
43 krb5_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 
54 static krb5_boolean
55 fail_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 
70 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
71 krb5_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;
178 cleanup:
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 
214 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
215 krb5_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