1 /* 2 * Crypto wrapper for internal crypto implementation - modexp 3 * Copyright (c) 2006-2009, Jouni Malinen <j (at) w1.fi> 4 * 5 * This software may be distributed under the terms of the BSD license. 6 * See README for more details. 7 */ 8 9 #include "includes.h" 10 11 #include "common.h" 12 #include "tls/bignum.h" 13 #include "crypto.h" 14 15 16 int crypto_mod_exp(const u8 *base, size_t base_len, 17 const u8 *power, size_t power_len, 18 const u8 *modulus, size_t modulus_len, 19 u8 *result, size_t *result_len) 20 { 21 struct bignum *bn_base, *bn_exp, *bn_modulus, *bn_result; 22 int ret = -1; 23 24 bn_base = bignum_init(); 25 bn_exp = bignum_init(); 26 bn_modulus = bignum_init(); 27 bn_result = bignum_init(); 28 29 if (bn_base == NULL || bn_exp == NULL || bn_modulus == NULL || 30 bn_result == NULL) 31 goto error; 32 33 if (bignum_set_unsigned_bin(bn_base, base, base_len) < 0 || 34 bignum_set_unsigned_bin(bn_exp, power, power_len) < 0 || 35 bignum_set_unsigned_bin(bn_modulus, modulus, modulus_len) < 0) 36 goto error; 37 38 if (bignum_exptmod(bn_base, bn_exp, bn_modulus, bn_result) < 0) 39 goto error; 40 41 ret = bignum_get_unsigned_bin(bn_result, result, result_len); 42 43 error: 44 bignum_deinit(bn_base); 45 bignum_deinit(bn_exp); 46 bignum_deinit(bn_modulus); 47 bignum_deinit(bn_result); 48 return ret; 49 } 50
