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/*
* (C) 2018 Jack Lloyd
*
* Botan is released under the Simplified BSD License (see license.txt)
*/
#ifndef BOTAN_POINT_MUL_H_
#define BOTAN_POINT_MUL_H_
#include <botan/point_gfp.h>
namespace Botan {
class Modular_Reducer;
static const size_t PointGFp_SCALAR_BLINDING_BITS = 80;
class PointGFp_Base_Point_Precompute final
{
public:
PointGFp_Base_Point_Precompute(const PointGFp& base_point,
const Modular_Reducer& mod_order);
PointGFp mul(const BigInt& k,
RandomNumberGenerator& rng,
const BigInt& group_order,
std::vector<BigInt>& ws) const;
private:
const PointGFp& m_base_point;
const Modular_Reducer& m_mod_order;
enum { WINDOW_BITS = 3 };
enum { WINDOW_SIZE = (1 << WINDOW_BITS) - 1 };
const size_t m_p_words;
const size_t m_T_size;
/*
* This is a table of T_size * 3*p_word words
*/
std::vector<word> m_W;
};
class PointGFp_Var_Point_Precompute final
{
public:
PointGFp_Var_Point_Precompute(const PointGFp& point,
RandomNumberGenerator& rng,
std::vector<BigInt>& ws);
PointGFp mul(const BigInt& k,
RandomNumberGenerator& rng,
const BigInt& group_order,
std::vector<BigInt>& ws) const;
private:
const CurveGFp m_curve;
const size_t m_p_words;
const size_t m_window_bits;
/*
* Table of 2^window_bits * 3*2*p_word words
* Kept in locked vector since the base point might be sensitive
* (normally isn't in most protocols but hard to say anything
* categorically.)
*/
secure_vector<word> m_T;
};
class PointGFp_Multi_Point_Precompute final
{
public:
PointGFp_Multi_Point_Precompute(const PointGFp& g1,
const PointGFp& g2);
/*
* Return (g1*k1 + g2*k2)
* Not constant time, intended to use with public inputs
*/
PointGFp multi_exp(const BigInt& k1,
const BigInt& k2) const;
private:
std::vector<PointGFp> m_M;
};
}
#endif
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