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/*
* (C) 2018 Jack Lloyd
*
* Botan is released under the Simplified BSD License (see license.txt)
*/
#ifndef BOTAN_MONTY_INT_H_
#define BOTAN_MONTY_INT_H_
#include <botan/bigint.h>
BOTAN_FUTURE_INTERNAL_HEADER(monty.h)
namespace Botan {
class Modular_Reducer;
class Montgomery_Params;
/**
* The Montgomery representation of an integer
*/
class BOTAN_UNSTABLE_API Montgomery_Int final
{
public:
/**
* Create a zero-initialized Montgomery_Int
*/
Montgomery_Int(std::shared_ptr<const Montgomery_Params> params) : m_params(params) {}
/**
* Create a Montgomery_Int
*/
Montgomery_Int(std::shared_ptr<const Montgomery_Params> params,
const BigInt& v,
bool redc_needed = true);
/**
* Create a Montgomery_Int
*/
Montgomery_Int(std::shared_ptr<const Montgomery_Params> params,
const uint8_t bits[], size_t len,
bool redc_needed = true);
/**
* Create a Montgomery_Int
*/
Montgomery_Int(std::shared_ptr<const Montgomery_Params> params,
const word words[], size_t len,
bool redc_needed = true);
bool operator==(const Montgomery_Int& other) const;
bool operator!=(const Montgomery_Int& other) const { return (m_v != other.m_v); }
std::vector<uint8_t> serialize() const;
size_t size() const;
bool is_one() const;
bool is_zero() const;
void fix_size();
/**
* Return the value to normal mod-p space
*/
BigInt value() const;
/**
* Return the Montgomery representation
*/
const BigInt& repr() const { return m_v; }
Montgomery_Int operator+(const Montgomery_Int& other) const;
Montgomery_Int operator-(const Montgomery_Int& other) const;
Montgomery_Int& operator+=(const Montgomery_Int& other);
Montgomery_Int& operator-=(const Montgomery_Int& other);
Montgomery_Int operator*(const Montgomery_Int& other) const;
Montgomery_Int& operator*=(const Montgomery_Int& other);
Montgomery_Int& operator*=(const secure_vector<word>& other);
Montgomery_Int& add(const Montgomery_Int& other,
secure_vector<word>& ws);
Montgomery_Int& sub(const Montgomery_Int& other,
secure_vector<word>& ws);
Montgomery_Int mul(const Montgomery_Int& other,
secure_vector<word>& ws) const;
Montgomery_Int& mul_by(const Montgomery_Int& other,
secure_vector<word>& ws);
Montgomery_Int& mul_by(const secure_vector<word>& other,
secure_vector<word>& ws);
Montgomery_Int square(secure_vector<word>& ws) const;
Montgomery_Int& square_this(secure_vector<word>& ws);
Montgomery_Int& square_this_n_times(secure_vector<word>& ws, size_t n);
Montgomery_Int multiplicative_inverse() const;
Montgomery_Int additive_inverse() const;
Montgomery_Int& mul_by_2(secure_vector<word>& ws);
Montgomery_Int& mul_by_3(secure_vector<word>& ws);
Montgomery_Int& mul_by_4(secure_vector<word>& ws);
Montgomery_Int& mul_by_8(secure_vector<word>& ws);
void const_time_poison() const { m_v.const_time_poison(); }
void const_time_unpoison() const { return m_v.const_time_unpoison(); }
private:
std::shared_ptr<const Montgomery_Params> m_params;
BigInt m_v;
};
/**
* Parameters for Montgomery Reduction
*/
class BOTAN_UNSTABLE_API Montgomery_Params final
{
public:
/**
* Initialize a set of Montgomery reduction parameters. These values
* can be shared by all values in a specific Montgomery domain.
*/
Montgomery_Params(const BigInt& p, const Modular_Reducer& mod_p);
/**
* Initialize a set of Montgomery reduction parameters. These values
* can be shared by all values in a specific Montgomery domain.
*/
Montgomery_Params(const BigInt& p);
const BigInt& p() const { return m_p; }
const BigInt& R1() const { return m_r1; }
const BigInt& R2() const { return m_r2; }
const BigInt& R3() const { return m_r3; }
word p_dash() const { return m_p_dash; }
size_t p_words() const { return m_p_words; }
BigInt redc(const BigInt& x,
secure_vector<word>& ws) const;
BigInt mul(const BigInt& x,
const BigInt& y,
secure_vector<word>& ws) const;
BigInt mul(const BigInt& x,
const secure_vector<word>& y,
secure_vector<word>& ws) const;
void mul_by(BigInt& x,
const secure_vector<word>& y,
secure_vector<word>& ws) const;
void mul_by(BigInt& x, const BigInt& y,
secure_vector<word>& ws) const;
BigInt sqr(const BigInt& x,
secure_vector<word>& ws) const;
void square_this(BigInt& x,
secure_vector<word>& ws) const;
BigInt inv_mod_p(const BigInt& x) const;
private:
BigInt m_p;
BigInt m_r1;
BigInt m_r2;
BigInt m_r3;
word m_p_dash;
size_t m_p_words;
};
}
#endif