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	ret = krb5_crypto_init(context, auth_context->keyblock,
112				   0, &crypto);
113
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	 * Retry using the subkey if we failed
127	 */
128	if (ret && auth_context->remote_subkey) {
129	    ret = krb5_crypto_init(context, auth_context->remote_subkey,
130				   0, &crypto);
131	    if (ret)
132		goto out;
133
134	    ret = krb5_decrypt_EncryptedData(context,
135					     crypto,
136					     KRB5_KU_KRB_CRED,
137					     &cred.enc_part,
138					     &enc_krb_cred_part_data);
139
140	    krb5_crypto_destroy(context, crypto);
141	}
142	if (ret)
143	    goto out;
144    }
145
146    ret = decode_EncKrbCredPart(enc_krb_cred_part_data.data,
147				enc_krb_cred_part_data.length,
148				&enc_krb_cred_part,
149				&len);
150    if (enc_krb_cred_part_data.data != cred.enc_part.cipher.data)
151	krb5_data_free(&enc_krb_cred_part_data);
152    if (ret) {
153	krb5_set_error_message(context, ret,
154			       N_("Failed to decode "
155				  "encrypte credential part", ""));
156	goto out;
157    }
158
159    /* check sender address */
160
161    if (enc_krb_cred_part.s_address
162	&& auth_context->remote_address
163	&& auth_context->remote_port) {
164	krb5_address *a;
165
166	ret = krb5_make_addrport (context, &a,
167				  auth_context->remote_address,
168				  auth_context->remote_port);
169	if (ret)
170	    goto out;
171
172
173	ret = compare_addrs(context, a, enc_krb_cred_part.s_address,
174			    N_("sender address is wrong "
175			       "in received creds", ""));
176	krb5_free_address(context, a);
177	free(a);
178	if(ret)
179	    goto out;
180    }
181
182    /* check receiver address */
183
184    if (enc_krb_cred_part.r_address
185	&& auth_context->local_address) {
186	if(auth_context->local_port &&
187	   enc_krb_cred_part.r_address->addr_type == KRB5_ADDRESS_ADDRPORT) {
188	    krb5_address *a;
189	    ret = krb5_make_addrport (context, &a,
190				      auth_context->local_address,
191				      auth_context->local_port);
192	    if (ret)
193		goto out;
194
195	    ret = compare_addrs(context, a, enc_krb_cred_part.r_address,
196				N_("receiver address is wrong "
197				   "in received creds", ""));
198	    krb5_free_address(context, a);
199	    free(a);
200	    if(ret)
201		goto out;
202	} else {
203	    ret = compare_addrs(context, auth_context->local_address,
204				enc_krb_cred_part.r_address,
205				N_("receiver address is wrong "
206				   "in received creds", ""));
207	    if(ret)
208		goto out;
209	}
210    }
211
212    /* check timestamp */
213    if (auth_context->flags & KRB5_AUTH_CONTEXT_DO_TIME) {
214	krb5_timestamp sec;
215
216	krb5_timeofday (context, &sec);
217
218	if (enc_krb_cred_part.timestamp == NULL ||
219	    enc_krb_cred_part.usec      == NULL ||
220	    krb5_time_abs(*enc_krb_cred_part.timestamp, sec)
221	    > context->max_skew) {
222	    krb5_clear_error_message (context);
223	    ret = KRB5KRB_AP_ERR_SKEW;
224	    goto out;
225	}
226    }
227
228    if ((auth_context->flags &
229	 (KRB5_AUTH_CONTEXT_RET_TIME | KRB5_AUTH_CONTEXT_RET_SEQUENCE))) {
230	/* if these fields are not present in the cred-part, silently
231           return zero */
232	memset(outdata, 0, sizeof(*outdata));
233	if(enc_krb_cred_part.timestamp)
234	    outdata->timestamp = *enc_krb_cred_part.timestamp;
235	if(enc_krb_cred_part.usec)
236	    outdata->usec = *enc_krb_cred_part.usec;
237	if(enc_krb_cred_part.nonce)
238	    outdata->seq = *enc_krb_cred_part.nonce;
239    }
240
241    /* Convert to NULL terminated list of creds */
242
243    *ret_creds = calloc(enc_krb_cred_part.ticket_info.len + 1,
244			sizeof(**ret_creds));
245
246    if (*ret_creds == NULL) {
247	ret = ENOMEM;
248	krb5_set_error_message(context, ret,
249			       N_("malloc: out of memory", ""));
250	goto out;
251    }
252
253    for (i = 0; i < enc_krb_cred_part.ticket_info.len; ++i) {
254	KrbCredInfo *kci = &enc_krb_cred_part.ticket_info.val[i];
255	krb5_creds *creds;
256
257	creds = calloc(1, sizeof(*creds));
258	if(creds == NULL) {
259	    ret = ENOMEM;
260	    krb5_set_error_message(context, ret,
261				   N_("malloc: out of memory", ""));
262	    goto out;
263	}
264
265	ASN1_MALLOC_ENCODE(Ticket, creds->ticket.data, creds->ticket.length,
266			   &cred.tickets.val[i], &len, ret);
267	if (ret) {
268	    free(creds);
269	    goto out;
270	}
271	if(creds->ticket.length != len)
272	    krb5_abortx(context, "internal error in ASN.1 encoder");
273	copy_EncryptionKey (&kci->key, &creds->session);
274	if (kci->prealm && kci->pname)
275	    _krb5_principalname2krb5_principal (context,
276						&creds->client,
277						*kci->pname,
278						*kci->prealm);
279	if (kci->flags)
280	    creds->flags.b = *kci->flags;
281	if (kci->authtime)
282	    creds->times.authtime = *kci->authtime;
283	if (kci->starttime)
284	    creds->times.starttime = *kci->starttime;
285	if (kci->endtime)
286	    creds->times.endtime = *kci->endtime;
287	if (kci->renew_till)
288	    creds->times.renew_till = *kci->renew_till;
289	if (kci->srealm && kci->sname)
290	    _krb5_principalname2krb5_principal (context,
291						&creds->server,
292						*kci->sname,
293						*kci->srealm);
294	if (kci->caddr)
295	    krb5_copy_addresses (context,
296				 kci->caddr,
297				 &creds->addresses);
298
299	(*ret_creds)[i] = creds;
300
301    }
302    (*ret_creds)[i] = NULL;
303
304    free_KRB_CRED (&cred);
305    free_EncKrbCredPart(&enc_krb_cred_part);
306
307    return 0;
308
309  out:
310    free_EncKrbCredPart(&enc_krb_cred_part);
311    free_KRB_CRED (&cred);
312    if(*ret_creds) {
313	for(i = 0; (*ret_creds)[i]; i++)
314	    krb5_free_creds(context, (*ret_creds)[i]);
315	free(*ret_creds);
316	*ret_creds = NULL;
317    }
318    return ret;
319}
320
321KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
322krb5_rd_cred2 (krb5_context      context,
323	       krb5_auth_context auth_context,
324	       krb5_ccache       ccache,
325	       krb5_data         *in_data)
326{
327    krb5_error_code ret;
328    krb5_creds **creds;
329    int i;
330
331    ret = krb5_rd_cred(context, auth_context, in_data, &creds, NULL);
332    if(ret)
333	return ret;
334
335    /* Store the creds in the ccache */
336
337    for(i = 0; creds && creds[i]; i++) {
338	krb5_cc_store_cred(context, ccache, creds[i]);
339	krb5_free_creds(context, creds[i]);
340    }
341    free(creds);
342    return 0;
343}
344