55 lines
1.4 KiB
C
55 lines
1.4 KiB
C
/*
|
|
* Crypto wrapper for internal crypto implementation - modexp
|
|
* Copyright (c) 2006-2009, Jouni Malinen <j@w1.fi>
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License version 2 as
|
|
* published by the Free Software Foundation.
|
|
*
|
|
* Alternatively, this software may be distributed under the terms of BSD
|
|
* license.
|
|
*
|
|
* See README and COPYING for more details.
|
|
*/
|
|
|
|
#include "includes.h"
|
|
|
|
#include "common.h"
|
|
#include "tls/bignum.h"
|
|
#include "crypto.h"
|
|
|
|
|
|
int crypto_mod_exp(const u8 *base, size_t base_len,
|
|
const u8 *power, size_t power_len,
|
|
const u8 *modulus, size_t modulus_len,
|
|
u8 *result, size_t *result_len)
|
|
{
|
|
struct bignum *bn_base, *bn_exp, *bn_modulus, *bn_result;
|
|
int ret = -1;
|
|
|
|
bn_base = bignum_init();
|
|
bn_exp = bignum_init();
|
|
bn_modulus = bignum_init();
|
|
bn_result = bignum_init();
|
|
|
|
if (bn_base == NULL || bn_exp == NULL || bn_modulus == NULL ||
|
|
bn_result == NULL)
|
|
goto error;
|
|
|
|
if (bignum_set_unsigned_bin(bn_base, base, base_len) < 0 ||
|
|
bignum_set_unsigned_bin(bn_exp, power, power_len) < 0 ||
|
|
bignum_set_unsigned_bin(bn_modulus, modulus, modulus_len) < 0)
|
|
goto error;
|
|
|
|
if (bignum_exptmod(bn_base, bn_exp, bn_modulus, bn_result) < 0)
|
|
goto error;
|
|
|
|
ret = bignum_get_unsigned_bin(bn_result, result, result_len);
|
|
|
|
error:
|
|
bignum_deinit(bn_base);
|
|
bignum_deinit(bn_exp);
|
|
bignum_deinit(bn_modulus);
|
|
bignum_deinit(bn_result);
|
|
return ret;
|
|
}
|