/* -*- mode: c; c-basic-offset: 4; indent-tabs-mode: nil -*- */
/* lib/crypto/krb/prf_cmac.c - CMAC-based PRF */
/*
* Copyright (C) 2010 by the Massachusetts Institute of Technology.
* 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 M.I.T. not be used in advertising or publicity pertaining
* to distribution of the software without specific, written prior
* permission. Furthermore if you modify this software you must label
* your software as modified software and not distribute it in such a
* fashion that it might be confused with the original M.I.T. software.
* M.I.T. makes no representations about the suitability of
* this software for any purpose. It is provided "as is" without express
* or implied warranty.
*/
#include "crypto_int.h"
krb5_error_code
krb5int_dk_cmac_prf(const struct krb5_keytypes *ktp, krb5_key key,
const krb5_data *in, krb5_data *out)
{
krb5_crypto_iov iov;
krb5_data prfconst = make_data("prf", 3);
krb5_key kp = NULL;
krb5_error_code ret;
if (ktp->prf_length != ktp->enc->block_size)
return KRB5_BAD_MSIZE;
iov.flags = KRB5_CRYPTO_TYPE_DATA;
iov.data = *in;
/* Derive a key using the PRF constant. */
ret = krb5int_derive_key(ktp->enc, NULL, key, &kp, &prfconst,
DERIVE_SP800_108_CMAC);
if (ret != 0)
goto cleanup;
/* PRF is CMAC of input */
ret = krb5int_cmac_checksum(ktp->enc, kp, &iov, 1, out);
if (ret != 0)
goto cleanup;
cleanup:
krb5_k_free_key(NULL, kp);
return ret;
}