1 /* -*- mode: c; c-basic-offset: 4; indent-tabs-mode: nil -*- */
2 /* lib/crypto/krb/verify_checksum_iov.c */
3 /*
4 * Copyright 2008 by the Massachusetts Institute of Technology.
5 * All Rights Reserved.
6 *
7 * Export of this software from the United States of America may
8 * require a specific license from the United States Government.
9 * It is the responsibility of any person or organization contemplating
10 * export to 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 M.I.T. not be used in advertising or publicity pertaining
18 * to distribution of the software without specific, written prior
19 * permission. Furthermore if you modify this software you must label
20 * your software as modified software and not distribute it in such a
21 * fashion that it might be confused with the original M.I.T. software.
22 * M.I.T. makes no representations about the suitability of
23 * this software for any purpose. It is provided "as is" without express
24 * or implied warranty.
25 */
26
27 #include "crypto_int.h"
28
29 krb5_error_code KRB5_CALLCONV
krb5_k_verify_checksum_iov(krb5_context context,krb5_cksumtype checksum_type,krb5_key key,krb5_keyusage usage,const krb5_crypto_iov * data,size_t num_data,krb5_boolean * valid)30 krb5_k_verify_checksum_iov(krb5_context context,
31 krb5_cksumtype checksum_type,
32 krb5_key key,
33 krb5_keyusage usage,
34 const krb5_crypto_iov *data,
35 size_t num_data,
36 krb5_boolean *valid)
37 {
38 const struct krb5_cksumtypes *ctp;
39 krb5_error_code ret;
40 krb5_data computed;
41 krb5_crypto_iov *checksum;
42
43 if (checksum_type == 0 && key != NULL) {
44 ret = krb5int_c_mandatory_cksumtype(context, key->keyblock.enctype,
45 &checksum_type);
46 if (ret != 0)
47 return ret;
48 }
49 ctp = find_cksumtype(checksum_type);
50 if (ctp == NULL)
51 return KRB5_BAD_ENCTYPE;
52
53 ret = verify_key(ctp, key);
54 if (ret != 0)
55 return ret;
56
57 checksum = krb5int_c_locate_iov((krb5_crypto_iov *)data, num_data,
58 KRB5_CRYPTO_TYPE_CHECKSUM);
59 if (checksum == NULL || checksum->data.length != ctp->output_size)
60 return KRB5_BAD_MSIZE;
61
62 /* If there's actually a verify function, call it. */
63 if (ctp->verify != NULL) {
64 return ctp->verify(ctp, key, usage, data, num_data, &checksum->data,
65 valid);
66 }
67
68 ret = alloc_data(&computed, ctp->compute_size);
69 if (ret != 0)
70 return ret;
71
72 ret = ctp->checksum(ctp, key, usage, data, num_data, &computed);
73 if (ret == 0) {
74 *valid = (k5_bcmp(computed.data, checksum->data.data,
75 ctp->output_size) == 0);
76 }
77
78 zapfree(computed.data, ctp->compute_size);
79 return ret;
80 }
81
82 krb5_error_code KRB5_CALLCONV
krb5_c_verify_checksum_iov(krb5_context context,krb5_cksumtype checksum_type,const krb5_keyblock * keyblock,krb5_keyusage usage,const krb5_crypto_iov * data,size_t num_data,krb5_boolean * valid)83 krb5_c_verify_checksum_iov(krb5_context context,
84 krb5_cksumtype checksum_type,
85 const krb5_keyblock *keyblock,
86 krb5_keyusage usage,
87 const krb5_crypto_iov *data,
88 size_t num_data,
89 krb5_boolean *valid)
90 {
91 krb5_key key = NULL;
92 krb5_error_code ret;
93
94 if (keyblock != NULL) {
95 ret = krb5_k_create_key(context, keyblock, &key);
96 if (ret != 0)
97 return ret;
98 }
99 ret = krb5_k_verify_checksum_iov(context, checksum_type, key, usage, data,
100 num_data, valid);
101 krb5_k_free_key(context, key);
102 return ret;
103 }
104