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/*
* 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_DLLIMP krb5_error_code KRB5_CALLCONV
krb5_c_verify_checksum(context, key, usage, data, cksum, valid)
krb5_context context;
krb5_const krb5_keyblock *key;
krb5_keyusage usage;
krb5_const krb5_data *data;
krb5_const krb5_checksum *cksum;
krb5_boolean *valid;
{
int i;
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);
/* if there's actually a verify function, call it */
indata.length = cksum->length;
indata.data = cksum->contents;
if (krb5_cksumtypes_list[i].keyhash &&
krb5_cksumtypes_list[i].keyhash->verify)
return((*(krb5_cksumtypes_list[i].keyhash->verify))(key, 0, data,
&indata, valid));
/* otherwise, make the checksum again, and compare */
if ((ret = krb5_c_checksum_length(context, cksum->checksum_type, &hashsize)))
return(ret);
if (cksum->length != hashsize)
return(KRB5_BAD_MSIZE);
computed.length = hashsize;
if ((ret = krb5_c_make_checksum(context, cksum->checksum_type, key, usage,
data, &computed))) {
free(computed.contents);
return(ret);
}
*valid = (memcmp(computed.contents, cksum->contents, hashsize) == 0);
free(computed.contents);
return(0);
}
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