1/*
2 * Copyright (c) 1997 - 2007 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
36static krb5_error_code
37compare_addrs(krb5_context context,
38	      krb5_address *a,
39	      krb5_address *b,
40	      const char *message)
41{
42    char a_str[64], b_str[64];
43    size_t len;
44
45    if(krb5_address_compare (context, a, b))
46	return 0;
47
48    krb5_print_address (a, a_str, sizeof(a_str), &len);
49    krb5_print_address (b, b_str, sizeof(b_str), &len);
50    krb5_set_error_message(context, KRB5KRB_AP_ERR_BADADDR,
51			   "%s: %s != %s", message, b_str, a_str);
52    return KRB5KRB_AP_ERR_BADADDR;
53}
54
55KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
56krb5_rd_cred(krb5_context context,
57	     krb5_auth_context auth_context,
58	     krb5_data *in_data,
59	     krb5_creds ***ret_creds,
60	     krb5_replay_data *outdata)
61{
62    krb5_error_code ret;
63    size_t len;
64    KRB_CRED cred;
65    EncKrbCredPart enc_krb_cred_part;
66    krb5_data enc_krb_cred_part_data;
67    krb5_crypto crypto;
68    size_t i;
69
70    memset(&enc_krb_cred_part, 0, sizeof(enc_krb_cred_part));
71    krb5_data_zero(&enc_krb_cred_part_data);
72
73    if ((auth_context->flags &
74	 (KRB5_AUTH_CONTEXT_RET_TIME | KRB5_AUTH_CONTEXT_RET_SEQUENCE)) &&
75	outdata == NULL)
76	return KRB5_RC_REQUIRED; /* XXX better error, MIT returns this */
77
78    *ret_creds = NULL;
79
80    ret = decode_KRB_CRED(in_data->data, in_data->length,
81			  &cred, &len);
82    if(ret) {
83	krb5_clear_error_message(context);
84	return ret;
85    }
86
87    if (cred.pvno != 5) {
88	ret = KRB5KRB_AP_ERR_BADVERSION;
89	krb5_clear_error_message (context);
90	goto out;
91    }
92
93    if (cred.msg_type != krb_cred) {
94	ret = KRB5KRB_AP_ERR_MSG_TYPE;
95	krb5_clear_error_message (context);
96	goto out;
97    }
98
99    if (cred.enc_part.etype == ETYPE_NULL) {
100	/* DK: MIT GSS-API Compatibility */
101	enc_krb_cred_part_data.length = cred.enc_part.cipher.length;
102	enc_krb_cred_part_data.data   = cred.enc_part.cipher.data;
103    } else {
104	/* Try both subkey and session key.
105	 *
106	 * RFC4120 claims we should use the session key, but Heimdal
107	 * before 0.8 used the remote subkey if it was send in the
108	 * auth_context.
109	 */
110
111	if (auth_context->remote_subkey) {
112	    ret = krb5_crypto_init(context, auth_context->remote_subkey,
113				   0, &crypto);
114	    if (ret)
115		goto out;
116
117	    ret = krb5_decrypt_EncryptedData(context,
118					     crypto,
119					     KRB5_KU_KRB_CRED,
120					     &cred.enc_part,
121					     &enc_krb_cred_part_data);
122
123	    krb5_crypto_destroy(context, crypto);
124	}
125
126	/*
127	 * If there was not subkey, or we failed using subkey,
128	 * retry using the session key
129	 */
130	if (auth_context->remote_subkey == NULL || ret == KRB5KRB_AP_ERR_BAD_INTEGRITY)
131	{
132
133	    ret = krb5_crypto_init(context, auth_context->keyblock,
134				   0, &crypto);
135
136	    if (ret)
137		goto out;
138
139	    ret = krb5_decrypt_EncryptedData(context,
140					     crypto,
141					     KRB5_KU_KRB_CRED,
142					     &cred.enc_part,
143					     &enc_krb_cred_part_data);
144
145	    krb5_crypto_destroy(context, crypto);
146	}
147	if (ret)
148	    goto out;
149    }
150
151    ret = decode_EncKrbCredPart(enc_krb_cred_part_data.data,
152				enc_krb_cred_part_data.length,
153				&enc_krb_cred_part,
154				&len);
155    if (enc_krb_cred_part_data.data != cred.enc_part.cipher.data)
156	krb5_data_free(&enc_krb_cred_part_data);
157    if (ret) {
158	krb5_set_error_message(context, ret,
159			       N_("Failed to decode "
160				  "encrypte credential part", ""));
161	goto out;
162    }
163
164    /* check sender address */
165
166    if (enc_krb_cred_part.s_address
167	&& auth_context->remote_address
168	&& auth_context->remote_port) {
169	krb5_address *a;
170
171	ret = krb5_make_addrport (context, &a,
172				  auth_context->remote_address,
173				  auth_context->remote_port);
174	if (ret)
175	    goto out;
176
177
178	ret = compare_addrs(context, a, enc_krb_cred_part.s_address,
179			    N_("sender address is wrong "
180			       "in received creds", ""));
181	krb5_free_address(context, a);
182	free(a);
183	if(ret)
184	    goto out;
185    }
186
187    /* check receiver address */
188
189    if (enc_krb_cred_part.r_address
190	&& auth_context->local_address) {
191	if(auth_context->local_port &&
192	   enc_krb_cred_part.r_address->addr_type == KRB5_ADDRESS_ADDRPORT) {
193	    krb5_address *a;
194	    ret = krb5_make_addrport (context, &a,
195				      auth_context->local_address,
196				      auth_context->local_port);
197	    if (ret)
198		goto out;
199
200	    ret = compare_addrs(context, a, enc_krb_cred_part.r_address,
201				N_("receiver address is wrong "
202				   "in received creds", ""));
203	    krb5_free_address(context, a);
204	    free(a);
205	    if(ret)
206		goto out;
207	} else {
208	    ret = compare_addrs(context, auth_context->local_address,
209				enc_krb_cred_part.r_address,
210				N_("receiver address is wrong "
211				   "in received creds", ""));
212	    if(ret)
213		goto out;
214	}
215    }
216
217    /* check timestamp */
218    if (auth_context->flags & KRB5_AUTH_CONTEXT_DO_TIME) {
219	krb5_timestamp sec;
220
221	krb5_timeofday (context, &sec);
222
223	if (enc_krb_cred_part.timestamp == NULL ||
224	    enc_krb_cred_part.usec      == NULL ||
225	    abs(*enc_krb_cred_part.timestamp - sec)
226	    > context->max_skew) {
227	    krb5_clear_error_message (context);
228	    ret = KRB5KRB_AP_ERR_SKEW;
229	    goto out;
230	}
231    }
232
233    if ((auth_context->flags &
234	 (KRB5_AUTH_CONTEXT_RET_TIME | KRB5_AUTH_CONTEXT_RET_SEQUENCE))) {
235	/* if these fields are not present in the cred-part, silently
236           return zero */
237	memset(outdata, 0, sizeof(*outdata));
238	if(enc_krb_cred_part.timestamp)
239	    outdata->timestamp = *enc_krb_cred_part.timestamp;
240	if(enc_krb_cred_part.usec)
241	    outdata->usec = *enc_krb_cred_part.usec;
242	if(enc_krb_cred_part.nonce)
243	    outdata->seq = *enc_krb_cred_part.nonce;
244    }
245
246    /* Convert to NULL terminated list of creds */
247
248    *ret_creds = calloc(enc_krb_cred_part.ticket_info.len + 1,
249			sizeof(**ret_creds));
250
251    if (*ret_creds == NULL) {
252	ret = ENOMEM;
253	krb5_set_error_message(context, ret,
254			       N_("malloc: out of memory", ""));
255	goto out;
256    }
257
258    for (i = 0; i < enc_krb_cred_part.ticket_info.len; ++i) {
259	KrbCredInfo *kci = &enc_krb_cred_part.ticket_info.val[i];
260	krb5_creds *creds;
261
262	creds = calloc(1, sizeof(*creds));
263	if(creds == NULL) {
264	    ret = ENOMEM;
265	    krb5_set_error_message(context, ret,
266				   N_("malloc: out of memory", ""));
267	    goto out;
268	}
269
270	ASN1_MALLOC_ENCODE(Ticket, creds->ticket.data, creds->ticket.length,
271			   &cred.tickets.val[i], &len, ret);
272	if (ret) {
273	    free(creds);
274	    goto out;
275	}
276	if(creds->ticket.length != len)
277	    krb5_abortx(context, "internal error in ASN.1 encoder");
278	copy_EncryptionKey (&kci->key, &creds->session);
279	if (kci->prealm && kci->pname)
280	    _krb5_principalname2krb5_principal (context,
281						&creds->client,
282						*kci->pname,
283						*kci->prealm);
284	if (kci->flags)
285	    creds->flags.b = *kci->flags;
286	if (kci->authtime)
287	    creds->times.authtime = *kci->authtime;
288	if (kci->starttime)
289	    creds->times.starttime = *kci->starttime;
290	if (kci->endtime)
291	    creds->times.endtime = *kci->endtime;
292	if (kci->renew_till)
293	    creds->times.renew_till = *kci->renew_till;
294	if (kci->srealm && kci->sname)
295	    _krb5_principalname2krb5_principal (context,
296						&creds->server,
297						*kci->sname,
298						*kci->srealm);
299	if (kci->caddr)
300	    krb5_copy_addresses (context,
301				 kci->caddr,
302				 &creds->addresses);
303
304	(*ret_creds)[i] = creds;
305
306    }
307    (*ret_creds)[i] = NULL;
308
309    free_KRB_CRED (&cred);
310    free_EncKrbCredPart(&enc_krb_cred_part);
311
312    return 0;
313
314  out:
315    free_EncKrbCredPart(&enc_krb_cred_part);
316    free_KRB_CRED (&cred);
317    if(*ret_creds) {
318	for(i = 0; (*ret_creds)[i]; i++)
319	    krb5_free_creds(context, (*ret_creds)[i]);
320	free(*ret_creds);
321	*ret_creds = NULL;
322    }
323    return ret;
324}
325
326KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
327krb5_rd_cred2 (krb5_context      context,
328	       krb5_auth_context auth_context,
329	       krb5_ccache       ccache,
330	       krb5_data         *in_data)
331{
332    krb5_error_code ret;
333    krb5_creds **creds;
334    int i;
335
336    ret = krb5_rd_cred(context, auth_context, in_data, &creds, NULL);
337    if(ret)
338	return ret;
339
340    /* Store the creds in the ccache */
341
342    for(i = 0; creds && creds[i]; i++) {
343	krb5_cc_store_cred(context, ccache, creds[i]);
344	krb5_free_creds(context, creds[i]);
345    }
346    free(creds);
347    return 0;
348}
349