crypto_internal-modexp.c File Reference

Crypto wrapper for internal crypto implementation - modexp. More...

#include "includes.h"
#include "common.h"
#include "tls/bignum.h"
#include "crypto.h"

Functions
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)
	Modular exponentiation of large integers. More...

Detailed Description

Crypto wrapper for internal crypto implementation - modexp.

Function Documentation

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
	)

Modular exponentiation of large integers.

Parameters

base	Base integer (big endian byte array)
base_len	Length of base integer in bytes
power	Power integer (big endian byte array)
power_len	Length of power integer in bytes
modulus	Modulus integer (big endian byte array)
modulus_len	Length of modulus integer in bytes
result	Buffer for the result
result_len	Result length (max buffer size on input, real len on output)

Returns

0 on success, -1 on failure

This function calculates result = base ^ power mod modulus. modules_len is used as the maximum size of modulus buffer. It is set to the used size on success.

This function is only used with internal TLSv1 implementation (CONFIG_TLS=internal). If that is not used, the crypto wrapper does not need to implement this.