1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
|
/*
* Copyright (C) 1998 by the FundsXpress, INC.
*
* All rights reserved.
*
* Export of this software from the United States of America may require
* a specific license from the United States Government. It is the
* responsibility of any person or organization contemplating export to
* obtain such a license before exporting.
*
* WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
* distribute this software and its documentation for any purpose and
* without fee is hereby granted, provided that the above copyright
* notice appear in all copies and that both that copyright notice and
* this permission notice appear in supporting documentation, and that
* the name of FundsXpress. not be used in advertising or publicity pertaining
* to distribution of the software without specific, written prior
* permission. FundsXpress makes no representations about the suitability of
* this software for any purpose. It is provided "as is" without express
* or implied warranty.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
* WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*/
#include "k5-int.h"
#include "cksumtypes.h"
krb5_error_code KRB5_CALLCONV
krb5_c_verify_checksum(krb5_context context, const krb5_keyblock *key,
krb5_keyusage usage, const krb5_data *data,
const krb5_checksum *cksum, krb5_boolean *valid)
{
unsigned int i;
const struct krb5_cksumtypes *ctp;
const struct krb5_keyhash_provider *keyhash;
size_t hashsize;
krb5_error_code ret;
krb5_data indata;
krb5_checksum computed;
for (i=0; i<krb5_cksumtypes_length; i++) {
if (krb5_cksumtypes_list[i].ctype == cksum->checksum_type)
break;
}
if (i == krb5_cksumtypes_length)
return KRB5_BAD_ENCTYPE;
ctp = &krb5_cksumtypes_list[i];
indata.length = cksum->length;
indata.data = (char *) cksum->contents;
/* If there's actually a verify function, call it. */
if (ctp->keyhash) {
keyhash = ctp->keyhash;
if (keyhash->verify == NULL && keyhash->verify_iov != NULL) {
krb5_crypto_iov iov[1];
iov[0].flags = KRB5_CRYPTO_TYPE_DATA;
iov[0].data = *data;
return (*keyhash->verify_iov)(key, usage, 0, iov, 1, &indata,
valid);
} else if (keyhash->verify != NULL) {
return (*keyhash->verify)(key, usage, 0, data, &indata, valid);
}
}
/* Otherwise, make the checksum again, and compare. */
ret = krb5_c_checksum_length(context, cksum->checksum_type, &hashsize);
if (ret)
return ret;
if (cksum->length != hashsize)
return KRB5_BAD_MSIZE;
computed.length = hashsize;
ret = krb5_c_make_checksum(context, cksum->checksum_type, key, usage,
data, &computed);
if (ret)
return ret;
*valid = (memcmp(computed.contents, cksum->contents, hashsize) == 0);
free(computed.contents);
return 0;
}
|
