Botan::Montgomery_Int Class Reference

#include <monty.h>

Public Member Functions
Montgomery_Int &	add (const Montgomery_Int &other, secure_vector< word > &ws)
Montgomery_Int	additive_inverse () const
void	const_time_poison () const
void	const_time_unpoison () const
void	fix_size ()
bool	is_one () const
bool	is_zero () const
	Montgomery_Int (std::shared_ptr< const Montgomery_Params > params)
	Montgomery_Int (std::shared_ptr< const Montgomery_Params > params, const BigInt &v, bool redc_needed=true)
	Montgomery_Int (std::shared_ptr< const Montgomery_Params > params, const uint8_t bits[], size_t len, bool redc_needed=true)
	Montgomery_Int (std::shared_ptr< const Montgomery_Params > params, const word words[], size_t len, bool redc_needed=true)
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 &	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)
Montgomery_Int	multiplicative_inverse () const
bool	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 secure_vector< word > &other)
Montgomery_Int	operator+ (const Montgomery_Int &other) const
Montgomery_Int &	operator+= (const Montgomery_Int &other)
Montgomery_Int	operator- (const Montgomery_Int &other) const
Montgomery_Int &	operator-= (const Montgomery_Int &other)
bool	operator== (const Montgomery_Int &other) const
const BigInt &	repr () const
std::vector< uint8_t >	serialize () const
size_t	size () const
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 &	sub (const Montgomery_Int &other, secure_vector< word > &ws)
BigInt	value () const

Detailed Description

The Montgomery representation of an integer

Definition at line 21 of file monty.h.

Constructor & Destructor Documentation

Montgomery_Int() [1/4]

Botan::Montgomery_Int::Montgomery_Int ( std::shared_ptr< const Montgomery_Params >  params )

inline

Create a zero-initialized Montgomery_Int

Definition at line 27 of file monty.h.

Referenced by additive_inverse(), mul(), multiplicative_inverse(), operator*(), operator+(), operator-(), and square().

: m_params(params) {}

Montgomery_Int() [2/4]

Botan::Montgomery_Int::Montgomery_Int	(	std::shared_ptr< const Montgomery_Params >	params,
		const BigInt &	v,
		bool	redc_needed = true
	)

Create a Montgomery_Int

Definition at line 222 of file monty.cpp.

References BOTAN_ASSERT_NOMSG.

                                                 :
   m_params(params)
   {
   if(redc_needed == false)
      {
      m_v = v;
      }
   else
      {
      BOTAN_ASSERT_NOMSG(m_v < m_params->p());
      secure_vector<word> ws;
      m_v = m_params->mul(v, m_params->R2(), ws);
      }
   }

Montgomery_Int() [3/4]

Botan::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

Definition at line 239 of file monty.cpp.

References BOTAN_ASSERT_NOMSG.

                                                 :
   m_params(params),
   m_v(bits, len)
   {
   if(redc_needed)
      {
      BOTAN_ASSERT_NOMSG(m_v < m_params->p());
      secure_vector<word> ws;
      m_v = m_params->mul(m_v, m_params->R2(), ws);
      }
   }

Montgomery_Int() [4/4]

Botan::Montgomery_Int::Montgomery_Int	(	std::shared_ptr< const Montgomery_Params >	params,
		const word	words[],
		size_t	len,
		bool	redc_needed = true
	)

Create a Montgomery_Int

Definition at line 253 of file monty.cpp.

References BOTAN_ASSERT_NOMSG.

                                                 :
   m_params(params),
   m_v(words, len)
   {
   if(redc_needed)
      {
      BOTAN_ASSERT_NOMSG(m_v < m_params->p());
      secure_vector<word> ws;
      m_v = m_params->mul(m_v, m_params->R2(), ws);
      }
   }

Member Function Documentation

add()

Montgomery_Int & Botan::Montgomery_Int::add	(	const Montgomery_Int &	other,
		secure_vector< word > &	ws
	)

Definition at line 338 of file monty.cpp.

References Botan::BigInt::mod_add().

Referenced by operator+=().

   {
   m_v.mod_add(other.m_v, m_params->p(), ws);
   return (*this);
   }

additive_inverse()

Montgomery_Int Botan::Montgomery_Int::additive_inverse

(

)

const

Definition at line 419 of file monty.cpp.

References Montgomery_Int().

   {
   return Montgomery_Int(m_params, m_params->p()) - (*this);
   }

const_time_poison()

void Botan::Montgomery_Int::const_time_poison ( ) const

inline

Definition at line 118 of file monty.h.

{ m_v.const_time_poison(); }

const_time_unpoison()

void Botan::Montgomery_Int::const_time_unpoison ( ) const

inline

Definition at line 119 of file monty.h.

{ return m_v.const_time_unpoison(); }

fix_size()

void Botan::Montgomery_Int::fix_size

(

)

Definition at line 267 of file monty.cpp.

References Botan::BigInt::get_word_vector(), and Botan::BigInt::sig_words().

   {
   const size_t p_words = m_params->p_words();

   if(m_v.sig_words() > p_words)
      throw Internal_Error("Montgomery_Int::fix_size v too large");

   secure_vector<word>& w = m_v.get_word_vector();

   if(w.size() != p_words)
      {
      w.resize(p_words);
      w.shrink_to_fit();
      }
   }

is_one()

bool Botan::Montgomery_Int::is_one

(

)

const

Definition at line 300 of file monty.cpp.

   {
   return m_v == m_params->R1();
   }

is_zero()

bool Botan::Montgomery_Int::is_zero

(

)

const

Definition at line 305 of file monty.cpp.

References Botan::BigInt::is_zero().

   {
   return m_v.is_zero();
   }

mul()

Montgomery_Int Botan::Montgomery_Int::mul	(	const Montgomery_Int &	other,
		secure_vector< word > &	ws
	)		const

Definition at line 362 of file monty.cpp.

References Montgomery_Int().

Referenced by Botan::monty_multi_exp().

   {
   return Montgomery_Int(m_params, m_params->mul(m_v, other.m_v, ws), false);
   }

mul_by() [1/2]

Montgomery_Int & Botan::Montgomery_Int::mul_by	(	const Montgomery_Int &	other,
		secure_vector< word > &	ws
	)

Definition at line 368 of file monty.cpp.

Referenced by Botan::monty_multi_exp(), and operator*=().

   {
   m_params->mul_by(m_v, other.m_v, ws);
   return (*this);
   }

mul_by() [2/2]

Montgomery_Int & Botan::Montgomery_Int::mul_by	(	const secure_vector< word > &	other,
		secure_vector< word > &	ws
	)

Definition at line 375 of file monty.cpp.

   {
   m_params->mul_by(m_v, other, ws);
   return (*this);
   }

mul_by_2()

Montgomery_Int & Botan::Montgomery_Int::mul_by_2

(

secure_vector< word > &

ws

)

Definition at line 424 of file monty.cpp.

References Botan::BigInt::mod_mul().

   {
   m_v.mod_mul(2, m_params->p(), ws);
   return (*this);
   }

mul_by_3()

Montgomery_Int & Botan::Montgomery_Int::mul_by_3

(

secure_vector< word > &

ws

)

Definition at line 430 of file monty.cpp.

References Botan::BigInt::mod_mul().

   {
   m_v.mod_mul(3, m_params->p(), ws);
   return (*this);
   }

mul_by_4()

Montgomery_Int & Botan::Montgomery_Int::mul_by_4

(

secure_vector< word > &

ws

)

Definition at line 436 of file monty.cpp.

References Botan::BigInt::mod_mul().

   {
   m_v.mod_mul(4, m_params->p(), ws);
   return (*this);
   }

mul_by_8()

Montgomery_Int & Botan::Montgomery_Int::mul_by_8

(

secure_vector< word > &

ws

)

Definition at line 442 of file monty.cpp.

References Botan::BigInt::mod_mul().

   {
   m_v.mod_mul(8, m_params->p(), ws);
   return (*this);
   }

multiplicative_inverse()

Montgomery_Int Botan::Montgomery_Int::multiplicative_inverse

(

)

const

Definition at line 412 of file monty.cpp.

References Montgomery_Int().

   {
   secure_vector<word> ws;
   const BigInt iv = m_params->mul(m_params->inv_mod_p(m_v), m_params->R3(), ws);
   return Montgomery_Int(m_params, iv, false);
   }

operator!=()

bool Botan::Montgomery_Int::operator!= ( const Montgomery_Int &  other ) const

inline

Definition at line 51 of file monty.h.

{ return (m_v != other.m_v); }

operator*()

Montgomery_Int Botan::Montgomery_Int::operator*

(

const Montgomery_Int &

other

)

const

Definition at line 356 of file monty.cpp.

References Montgomery_Int().

   {
   secure_vector<word> ws;
   return Montgomery_Int(m_params, m_params->mul(m_v, other.m_v, ws), false);
   }

operator*=() [1/2]

Montgomery_Int & Botan::Montgomery_Int::operator*=

(

const Montgomery_Int &

other

)

Definition at line 382 of file monty.cpp.

References mul_by().

   {
   secure_vector<word> ws;
   return mul_by(other, ws);
   }

operator*=() [2/2]

Montgomery_Int & Botan::Montgomery_Int::operator*=

(

const secure_vector< word > &

other

)

Definition at line 388 of file monty.cpp.

References mul_by().

   {
   secure_vector<word> ws;
   return mul_by(other, ws);
   }

operator+()

Montgomery_Int Botan::Montgomery_Int::operator+

(

const Montgomery_Int &

other

)

const

Definition at line 316 of file monty.cpp.

References Botan::BigInt::mod_add(), and Montgomery_Int().

   {
   secure_vector<word> ws;
   BigInt z = m_v;
   z.mod_add(other.m_v, m_params->p(), ws);
   return Montgomery_Int(m_params, z, false);
   }

operator+=()

Montgomery_Int & Botan::Montgomery_Int::operator+=

(

const Montgomery_Int &

other

)

Definition at line 332 of file monty.cpp.

References add().

   {
   secure_vector<word> ws;
   return this->add(other, ws);
   }

operator-()

Montgomery_Int Botan::Montgomery_Int::operator-

(

const Montgomery_Int &

other

)

const

Definition at line 324 of file monty.cpp.

References Botan::BigInt::mod_sub(), and Montgomery_Int().

   {
   secure_vector<word> ws;
   BigInt z = m_v;
   z.mod_sub(other.m_v, m_params->p(), ws);
   return Montgomery_Int(m_params, z, false);
   }

operator-=()

Montgomery_Int & Botan::Montgomery_Int::operator-=

(

const Montgomery_Int &

other

)

Definition at line 344 of file monty.cpp.

References sub().

   {
   secure_vector<word> ws;
   return this->sub(other, ws);
   }

operator==()

bool Botan::Montgomery_Int::operator==

(

const Montgomery_Int &

other

)

const

Definition at line 283 of file monty.cpp.

   {
   return m_v == other.m_v && m_params->p() == other.m_params->p();
   }

repr()

const BigInt& Botan::Montgomery_Int::repr ( ) const

inline

Return the Montgomery representation

Definition at line 69 of file monty.h.

{ return m_v; }

serialize()

std::vector< uint8_t > Botan::Montgomery_Int::serialize

(

)

const

Definition at line 288 of file monty.cpp.

References Botan::BigInt::encode_1363(), size(), and value().

   {
   std::vector<uint8_t> v(size());
   BigInt::encode_1363(v.data(), v.size(), value());
   return v;
   }

size()

size_t Botan::Montgomery_Int::size

(

)

const

Definition at line 295 of file monty.cpp.

Referenced by serialize().

   {
   return m_params->p().bytes();
   }

square()

Montgomery_Int Botan::Montgomery_Int::square

(

secure_vector< word > &

ws

)

const

Definition at line 407 of file monty.cpp.

References Montgomery_Int().

Referenced by Botan::monty_multi_exp().

   {
   return Montgomery_Int(m_params, m_params->sqr(m_v, ws), false);
   }

square_this()

Montgomery_Int & Botan::Montgomery_Int::square_this

(

secure_vector< word > &

ws

)

Definition at line 401 of file monty.cpp.

Referenced by Botan::monty_multi_exp().

   {
   m_params->square_this(m_v, ws);
   return (*this);
   }

square_this_n_times()

Montgomery_Int & Botan::Montgomery_Int::square_this_n_times	(	secure_vector< word > &	ws,
		size_t	n
	)

Definition at line 394 of file monty.cpp.

   {
   for(size_t i = 0; i != n; ++i)
      m_params->square_this(m_v, ws);
   return (*this);
   }

sub()

Montgomery_Int & Botan::Montgomery_Int::sub	(	const Montgomery_Int &	other,
		secure_vector< word > &	ws
	)

Definition at line 350 of file monty.cpp.

References Botan::BigInt::mod_sub().

Referenced by operator-=().

   {
   m_v.mod_sub(other.m_v, m_params->p(), ws);
   return (*this);
   }

value()

BigInt Botan::Montgomery_Int::value

(

)

const

Return the value to normal mod-p space

Definition at line 310 of file monty.cpp.

Referenced by Botan::monty_multi_exp(), and serialize().

   {
   secure_vector<word> ws;
   return m_params->redc(m_v, ws);
   }

---

The documentation for this class was generated from the following files:

• src/lib/math/numbertheory/monty.h
• src/lib/math/numbertheory/monty.cpp