1 /* -*- mode: c; c-basic-offset: 4; indent-tabs-mode: nil -*- */
2 /*
3 * Copyright (C) 1998 by the FundsXpress, INC.
4 *
5 * All rights reserved.
6 *
7 * Export of this software from the United States of America may require
8 * a specific license from the United States Government. It is the
9 * responsibility of any person or organization contemplating export to
10 * obtain such a license before exporting.
11 *
12 * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
13 * distribute this software and its documentation for any purpose and
14 * without fee is hereby granted, provided that the above copyright
15 * notice appear in all copies and that both that copyright notice and
16 * this permission notice appear in supporting documentation, and that
17 * the name of FundsXpress. not be used in advertising or publicity pertaining
18 * to distribution of the software without specific, written prior
19 * permission. FundsXpress makes no representations about the suitability of
20 * this software for any purpose. It is provided "as is" without express
21 * or implied warranty.
22 *
23 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
24 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
25 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
26 */
27
28 #include "crypto_int.h"
29
30 krb5_error_code KRB5_CALLCONV
krb5_k_verify_checksum(krb5_context context,krb5_key key,krb5_keyusage usage,const krb5_data * data,const krb5_checksum * cksum,krb5_boolean * valid)31 krb5_k_verify_checksum(krb5_context context, krb5_key key,
32 krb5_keyusage usage, const krb5_data *data,
33 const krb5_checksum *cksum, krb5_boolean *valid)
34 {
35 const struct krb5_cksumtypes *ctp;
36 krb5_cksumtype cksumtype;
37 krb5_crypto_iov iov;
38 krb5_error_code ret;
39 krb5_data cksum_data;
40 krb5_checksum computed;
41
42 iov.flags = KRB5_CRYPTO_TYPE_DATA;
43 iov.data = *data;
44
45 /* A 0 checksum type means use the mandatory checksum. */
46 cksumtype = cksum->checksum_type;
47 if (cksumtype == 0 && key != NULL) {
48 ret = krb5int_c_mandatory_cksumtype(context, key->keyblock.enctype,
49 &cksumtype);
50 if (ret)
51 return ret;
52 }
53 ctp = find_cksumtype(cksumtype);
54 if (ctp == NULL)
55 return KRB5_BAD_ENCTYPE;
56
57 ret = verify_key(ctp, key);
58 if (ret != 0)
59 return ret;
60
61 /* If there's actually a verify function, call it. */
62 cksum_data = make_data(cksum->contents, cksum->length);
63 if (ctp->verify != NULL)
64 return ctp->verify(ctp, key, usage, &iov, 1, &cksum_data, valid);
65
66 /* Otherwise, make the checksum again, and compare. */
67 if (cksum->length != ctp->output_size)
68 return KRB5_BAD_MSIZE;
69
70 ret = krb5_k_make_checksum(context, cksum->checksum_type, key, usage,
71 data, &computed);
72 if (ret)
73 return ret;
74
75 *valid = (k5_bcmp(computed.contents, cksum->contents,
76 ctp->output_size) == 0);
77
78 free(computed.contents);
79 return 0;
80 }
81
82 krb5_error_code KRB5_CALLCONV
krb5_c_verify_checksum(krb5_context context,const krb5_keyblock * keyblock,krb5_keyusage usage,const krb5_data * data,const krb5_checksum * cksum,krb5_boolean * valid)83 krb5_c_verify_checksum(krb5_context context, const krb5_keyblock *keyblock,
84 krb5_keyusage usage, const krb5_data *data,
85 const krb5_checksum *cksum, krb5_boolean *valid)
86 {
87 krb5_key key = NULL;
88 krb5_error_code ret;
89
90 if (keyblock != NULL) {
91 ret = krb5_k_create_key(context, keyblock, &key);
92 if (ret != 0)
93 return ret;
94 }
95 ret = krb5_k_verify_checksum(context, key, usage, data, cksum, valid);
96 krb5_k_free_key(context, key);
97 return ret;
98 }
99