Botan::EC_Group::Mul2Table Class Reference

Table for computing g*x + h*y. More...

#include <ec_group.h>

Public Member Functions
std::optional< EC_AffinePoint >	mul2_vartime (const EC_Scalar &x, const EC_Scalar &y) const
bool	mul2_vartime_x_mod_order_eq (const EC_Scalar &v, const EC_Scalar &c, const EC_Scalar &x, const EC_Scalar &y) const
bool	mul2_vartime_x_mod_order_eq (const EC_Scalar &v, const EC_Scalar &x, const EC_Scalar &y) const
	Mul2Table (const EC_AffinePoint &h)
	~Mul2Table ()

Detailed Description

Table for computing g*x + h*y.

Definition at line 255 of file ec_group.h.

Constructor & Destructor Documentation

Mul2Table()

Botan::EC_Group::Mul2Table::Mul2Table

(

const EC_AffinePoint &

h

)

Create a table for computing g*x + h*y

Definition at line 639 of file ec_group.cpp.

: m_tbl(h._group()->make_mul2_table(h._inner())) {}

~Mul2Table()

Botan::EC_Group::Mul2Table::~Mul2Table ( )

default

Member Function Documentation

mul2_vartime()

std::optional< EC_AffinePoint > Botan::EC_Group::Mul2Table::mul2_vartime	(	const EC_Scalar &	x,
		const EC_Scalar &	y ) const

Return the elliptic curve point g*x + h*y

Where g is the group generator and h is the value passed to the constructor

Returns nullopt if g*x + h*y was the point at infinity

Warning

this function is variable time with respect to x and y

Definition at line 643 of file ec_group.cpp.

                                                                                                        {
   auto pt = m_tbl->mul2_vartime(x._inner(), y._inner());
   if(pt) {
      return EC_AffinePoint::_from_inner(std::move(pt));
   } else {
      return {};
   }
}

References Botan::EC_AffinePoint::_from_inner(), and Botan::EC_Scalar::_inner().

Referenced by Botan::EC_Group::point_multiply().

mul2_vartime_x_mod_order_eq() [1/2]

bool Botan::EC_Group::Mul2Table::mul2_vartime_x_mod_order_eq	(	const EC_Scalar &	v,
		const EC_Scalar &	c,
		const EC_Scalar &	x,
		const EC_Scalar &	y ) const

Check if v equals the x coordinate of g*x*c + h*y*c reduced modulo the order

Where g is the group generator and h is the value passed to the constructor

Returns false if unequal, including if g*x*c + h*y*c was the point at infinity

Warning

this function is variable time with respect to x and y

Definition at line 658 of file ec_group.cpp.

                                                                                {
   return this->mul2_vartime_x_mod_order_eq(v, c * x, c * y);
}

mul2_vartime_x_mod_order_eq() [2/2]

bool Botan::EC_Group::Mul2Table::mul2_vartime_x_mod_order_eq	(	const EC_Scalar &	v,
		const EC_Scalar &	x,
		const EC_Scalar &	y ) const

Check if v equals the x coordinate of g*x + h*y reduced modulo the order

Where g is the group generator and h is the value passed to the constructor

Returns false if unequal, including if g*x + h*y was the point at infinity

Warning

this function is variable time with respect to x and y

Definition at line 652 of file ec_group.cpp.

                                                                                {
   return m_tbl->mul2_vartime_x_mod_order_eq(v._inner(), x._inner(), y._inner());
}

References Botan::EC_Scalar::_inner().

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

• src/lib/pubkey/ec_group/ec_group.h
• src/lib/pubkey/ec_group/ec_group.cpp