Botan::AffineCurvePoint< FieldElement > Class Template Reference

#include <pcurves_impl.h>

Public Types
using	Self = AffineCurvePoint<FieldElement>

Public Member Functions
constexpr void	_const_time_poison () const
constexpr void	_const_time_unpoison () const
constexpr	AffineCurvePoint ()
constexpr	AffineCurvePoint (const FieldElement &x, const FieldElement &y)
	AffineCurvePoint (const Self &other)=default
	AffineCurvePoint (Self &&other)=default
constexpr void	conditional_assign (CT::Choice cond, const Self &pt)
constexpr CT::Choice	is_identity () const
constexpr Self	negate () const
AffineCurvePoint &	operator= (const Self &other)=default
AffineCurvePoint &	operator= (Self &&other)=default
constexpr void	serialize_to (std::span< uint8_t, Self::BYTES > bytes) const
constexpr const FieldElement &	x () const
constexpr const FieldElement &	y () const
	~AffineCurvePoint ()=default

Static Public Member Functions
static constexpr auto	ct_select (std::span< const Self > pts, size_t idx)
static constexpr Self	identity ()
static constexpr Self	identity (const Self &)

Static Public Attributes
static constexpr size_t	BYTES = 1 + 2 * FieldElement::BYTES

Detailed Description

template<typename FieldElement>
class Botan::AffineCurvePoint< FieldElement >

Affine Curve Point

This contains a pair of integers (x,y) which satisfy the curve equation

Definition at line 909 of file pcurves_impl.h.

Member Typedef Documentation

Self

template<typename FieldElement>

using Botan::AffineCurvePoint< FieldElement >::Self = AffineCurvePoint<FieldElement>

Definition at line 913 of file pcurves_impl.h.

Constructor & Destructor Documentation

AffineCurvePoint() [1/4]

template<typename FieldElement>

Botan::AffineCurvePoint< FieldElement >::AffineCurvePoint ( const FieldElement & x, const FieldElement & y )

inlineconstexpr

Definition at line 917 of file pcurves_impl.h.

: m_x(x), m_y(y) {}

References x(), and y().

Referenced by operator=(), and operator=().

AffineCurvePoint() [2/4]

template<typename FieldElement>

Botan::AffineCurvePoint< FieldElement >::AffineCurvePoint ( )

inlineconstexpr

Definition at line 919 of file pcurves_impl.h.

: m_x(FieldElement::zero()), m_y(FieldElement::zero()) {}

AffineCurvePoint() [3/4]

template<typename FieldElement>

Botan::AffineCurvePoint< FieldElement >::AffineCurvePoint ( const Self & other )

default

AffineCurvePoint() [4/4]

template<typename FieldElement>

Botan::AffineCurvePoint< FieldElement >::AffineCurvePoint ( Self && other )

default

~AffineCurvePoint()

template<typename FieldElement>

Botan::AffineCurvePoint< FieldElement >::~AffineCurvePoint ( )

default

Member Function Documentation

_const_time_poison()

template<typename FieldElement>

void Botan::AffineCurvePoint< FieldElement >::_const_time_poison ( ) const

inlineconstexpr

Definition at line 985 of file pcurves_impl.h.

{ CT::poison_all(m_x, m_y); }

References Botan::CT::poison_all().

_const_time_unpoison()

template<typename FieldElement>

void Botan::AffineCurvePoint< FieldElement >::_const_time_unpoison ( ) const

inlineconstexpr

Definition at line 987 of file pcurves_impl.h.

{ CT::unpoison_all(m_x, m_y); }

References Botan::CT::unpoison_all().

conditional_assign()

template<typename FieldElement>

void Botan::AffineCurvePoint< FieldElement >::conditional_assign ( CT::Choice cond, const Self & pt )

inlineconstexpr

Conditional assignment of an affine point

Definition at line 981 of file pcurves_impl.h.

                                                                       {
         FieldElement::conditional_assign(m_x, m_y, cond, pt.x(), pt.y());
      }

References x(), and y().

ct_select()

template<typename FieldElement>

constexpr auto Botan::AffineCurvePoint< FieldElement >::ct_select ( std::span< const Self > pts, size_t idx )

inlinestaticconstexpr

If idx is zero then return the identity element. Otherwise return pts[idx - 1]

Returns the identity element also if idx is out of range

Definition at line 955 of file pcurves_impl.h.

                                                                           {
         auto result = Self::identity(pts[0]);
 
         // Intentionally wrapping; set to maximum size_t if idx == 0
         const size_t idx1 = static_cast<size_t>(idx - 1);
         for(size_t i = 0; i != pts.size(); ++i) {
            const auto found = CT::Mask<size_t>::is_equal(idx1, i).as_choice();
            result.conditional_assign(found, pts[i]);
         }
 
         return result;
      }

References identity(), and Botan::CT::Mask< T >::is_equal().

identity() [1/2]

template<typename FieldElement>

constexpr Self Botan::AffineCurvePoint< FieldElement >::identity ( )

inlinestaticconstexpr

Definition at line 921 of file pcurves_impl.h.

{ return Self(FieldElement::zero(), FieldElement::zero()); }

Referenced by ct_select().

identity() [2/2]

template<typename FieldElement>

constexpr Self Botan::AffineCurvePoint< FieldElement >::identity ( const Self & )

inlinestaticconstexpr

Definition at line 924 of file pcurves_impl.h.

                                                    {
         return Self(FieldElement::zero(), FieldElement::zero());
      }

is_identity()

template<typename FieldElement>

CT::Choice Botan::AffineCurvePoint< FieldElement >::is_identity ( ) const

inlineconstexpr

Definition at line 928 of file pcurves_impl.h.

{ return x().is_zero() && y().is_zero(); }

References x(), and y().

Referenced by Botan::ProjectiveCurvePoint< FieldElement, Params >::from_affine(), and serialize_to().

negate()

template<typename FieldElement>

Self Botan::AffineCurvePoint< FieldElement >::negate ( ) const

inlineconstexpr

Definition at line 936 of file pcurves_impl.h.

{ return Self(x(), y().negate()); }

References negate(), x(), and y().

Referenced by negate().

operator=() [1/2]

template<typename FieldElement>

AffineCurvePoint & Botan::AffineCurvePoint< FieldElement >::operator= ( const Self & other )

default

References AffineCurvePoint().

operator=() [2/2]

template<typename FieldElement>

AffineCurvePoint & Botan::AffineCurvePoint< FieldElement >::operator= ( Self && other )

default

References AffineCurvePoint().

serialize_to()

template<typename FieldElement>

void Botan::AffineCurvePoint< FieldElement >::serialize_to ( std::span< uint8_t, Self::BYTES > bytes ) const

inlineconstexpr

Serialize the point in uncompressed format

Definition at line 941 of file pcurves_impl.h.

                                                                           {
         BOTAN_STATE_CHECK(this->is_identity().as_bool() == false);
         BufferStuffer pack(bytes);
         pack.append(0x04);
         x().serialize_to(pack.next<FieldElement::BYTES>());
         y().serialize_to(pack.next<FieldElement::BYTES>());
         BOTAN_DEBUG_ASSERT(pack.full());
      }

References BOTAN_DEBUG_ASSERT, BOTAN_STATE_CHECK, is_identity(), x(), and y().

x()

template<typename FieldElement>

const FieldElement & Botan::AffineCurvePoint< FieldElement >::x ( ) const

inlineconstexpr

Return the affine x coordinate

Definition at line 971 of file pcurves_impl.h.

{ return m_x; }

Referenced by AffineCurvePoint(), conditional_assign(), Botan::ProjectiveCurvePoint< FieldElement, Params >::from_affine(), is_identity(), negate(), and serialize_to().

y()

template<typename FieldElement>

const FieldElement & Botan::AffineCurvePoint< FieldElement >::y ( ) const

inlineconstexpr

Return the affine y coordinate

Definition at line 976 of file pcurves_impl.h.

{ return m_y; }

Referenced by AffineCurvePoint(), conditional_assign(), Botan::ProjectiveCurvePoint< FieldElement, Params >::from_affine(), is_identity(), negate(), and serialize_to().

Member Data Documentation

BYTES

template<typename FieldElement>

size_t Botan::AffineCurvePoint< FieldElement >::BYTES = 1 + 2 * FieldElement::BYTES

staticconstexpr

Definition at line 911 of file pcurves_impl.h.

---

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

• src/lib/math/pcurves/pcurves_impl/pcurves_impl.h