p256

package
v0.0.0-...-7685c8a Latest Latest
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 Go to latest Published: Feb 26, 2026 License: Apache-2.0 Imports: 20 Imported by: 0

README

p256

This package implements the NIST P-256 curve, field, scalar, and point types.

Documentation

Overview

Package p256 implements the NIST P-256 curve, field, scalar, and point types.

See README.md for details.

Index

Constants

View Source 
const (
	// CurveName is the curve name.
	CurveName = "P256"
	// Hash2CurveSuite is the hash-to-curve suite string.
	Hash2CurveSuite = "P256_XMD:SHA-256_SSWU_RO_"
	// Hash2CurveScalarSuite is the hash-to-curve scalar suite string.
	Hash2CurveScalarSuite = "P256_XMD:SHA-256_SSWU_RO_SC_"
)
View Source 
const (
	// BaseFieldName is the base field name.
	BaseFieldName = "P256Fp"
)
View Source 
const (
	// ScalarFieldName is the scalar field name.
	ScalarFieldName = "P256Fq"
)

Variables

This section is empty.

Functions

This section is empty.

Types

type BaseField 

type BaseField struct {
	traits.PrimeFieldTrait[*p256Impl.Fp, *BaseFieldElement, BaseFieldElement]
}

BaseField represents the curve base field.

func NewBaseField 

func NewBaseField() *BaseField

NewBaseField returns the base field instance.

func (*BaseField) BitLen 

func (*BaseField) BitLen() int

BitLen returns the field modulus bit length.

func (*BaseField) Characteristic 

func (*BaseField) Characteristic() cardinal.Cardinal

Characteristic returns the field characteristic.

func (*BaseField) ElementSize 

func (*BaseField) ElementSize() int

ElementSize returns the element size in bytes.

func (*BaseField) FromBytesBEReduce 

func (f *BaseField) FromBytesBEReduce(input []byte) (*BaseFieldElement, error)

FromBytesBEReduce reduces a big-endian integer into the field.

func (*BaseField) Hash 

func (*BaseField) Hash(bytes []byte) (*BaseFieldElement, error)

Hash maps input bytes to an element or point.

func (*BaseField) Name 

func (*BaseField) Name() string

Name returns the name of the structure.

func (*BaseField) Order 

func (*BaseField) Order() cardinal.Cardinal

Order returns the group or field order.

func (*BaseField) WideElementSize 

func (*BaseField) WideElementSize() int

WideElementSize returns the wide element size in bytes.

type BaseFieldElement 

type BaseFieldElement struct {
	traits.PrimeFieldElementTrait[*p256Impl.Fp, p256Impl.Fp, *BaseFieldElement, BaseFieldElement]
}

BaseFieldElement represents an element of the base field.

func (*BaseFieldElement) MarshalBinary 

func (fe *BaseFieldElement) MarshalBinary() (data []byte, err error)

MarshalBinary implements encoding.BinaryMarshaler.

func (*BaseFieldElement) MarshalCBOR 

func (fe *BaseFieldElement) MarshalCBOR() ([]byte, error)

MarshalCBOR implements cbor.Marshaler.

func (*BaseFieldElement) Structure 

func (*BaseFieldElement) Structure() algebra.Structure[*BaseFieldElement]

Structure returns the algebraic structure for the receiver.

func (*BaseFieldElement) UnmarshalBinary 

func (fe *BaseFieldElement) UnmarshalBinary(data []byte) error

UnmarshalBinary implements encoding.BinaryUnmarshaler.

func (*BaseFieldElement) UnmarshalCBOR 

func (fe *BaseFieldElement) UnmarshalCBOR(data []byte) error

UnmarshalCBOR implements cbor.Unmarshaler.

type Curve 

type Curve struct {
	traits.PrimeCurveTrait[*p256Impl.Fp, *p256Impl.Point, *Point, Point]
}

Curve represents the elliptic curve group.

func NewCurve 

func NewCurve() *Curve

NewCurve returns the curve instance.

func (*Curve) BaseField 

func (*Curve) BaseField() algebra.FiniteField[*BaseFieldElement]

BaseField returns the base field.

func (*Curve) BaseStructure 

func (*Curve) BaseStructure() algebra.Structure[*BaseFieldElement]

BaseStructure returns the base field structure.

func (*Curve) Cofactor 

func (*Curve) Cofactor() cardinal.Cardinal

Cofactor returns the curve cofactor.

func (*Curve) ElementSize 

func (*Curve) ElementSize() int

ElementSize returns the element size in bytes.

func (*Curve) FromAffine 

func (*Curve) FromAffine(x, y *BaseFieldElement) (*Point, error)

FromAffine builds a point from affine coordinates.

func (*Curve) FromAffineX 

func (*Curve) FromAffineX(x *BaseFieldElement, b bool) (*Point, error)

FromAffineX builds a point from an affine x-coordinate.

func (*Curve) FromBytes 

func (c *Curve) FromBytes(input []byte) (*Point, error)

FromBytes decodes an element from bytes.

func (*Curve) FromCompressed 

func (c *Curve) FromCompressed(input []byte) (*Point, error)

FromCompressed decodes a compressed point.

func (*Curve) FromUncompressed 

func (c *Curve) FromUncompressed(input []byte) (*Point, error)

FromUncompressed decodes an uncompressed point.

func (*Curve) FromWideBytes 

func (c *Curve) FromWideBytes(input []byte) (*Point, error)

FromWideBytes decodes an element from wide bytes.

func (*Curve) Hash 

func (c *Curve) Hash(bytes []byte) (*Point, error)

Hash maps input bytes to an element or point.

func (*Curve) HashWithDst 

func (*Curve) HashWithDst(dst string, bytes []byte) (*Point, error)

HashWithDst maps input bytes to a point with a custom DST.

func (*Curve) MultiScalarMul 

func (*Curve) MultiScalarMul(scalars []*Scalar, points []*Point) (*Point, error)

MultiScalarMul computes a multiscalar multiplication.

func (*Curve) MultiScalarOp 

func (c *Curve) MultiScalarOp(scalars []*Scalar, points []*Point) (*Point, error)

MultiScalarOp computes a multiscalar operation.

func (*Curve) Name 

func (*Curve) Name() string

Name returns the name of the structure.

func (*Curve) Order 

func (*Curve) Order() cardinal.Cardinal

Order returns the group or field order.

func (*Curve) ScalarBaseMul 

func (c *Curve) ScalarBaseMul(sc *Scalar) *Point

ScalarBaseMul multiplies the generator by a scalar.

func (*Curve) ScalarBaseOp 

func (c *Curve) ScalarBaseOp(sc *Scalar) *Point

ScalarBaseOp adds a scalar multiple of the generator.

func (*Curve) ScalarField 

func (*Curve) ScalarField() algebra.PrimeField[*Scalar]

ScalarField returns the scalar field.

func (*Curve) ScalarRing 

func (*Curve) ScalarRing() algebra.ZModLike[*Scalar]

ScalarRing returns the scalar ring.

func (*Curve) ScalarStructure 

func (*Curve) ScalarStructure() algebra.Structure[*Scalar]

ScalarStructure returns the scalar structure.

func (*Curve) ToElliptic 

func (*Curve) ToElliptic() elliptic.Curve

ToElliptic returns the standard library elliptic.Curve adapter.

func (*Curve) WideElementSize 

func (*Curve) WideElementSize() int

WideElementSize returns the wide element size in bytes.

type Point 

type Point struct {
	traits.PrimePointTrait[*p256Impl.Fp, *p256Impl.Point, p256Impl.Point, *Point, Point]
}

Point represents a curve point.

func (*Point) AffineX 

func (p *Point) AffineX() (*BaseFieldElement, error)

AffineX returns the affine x-coordinate.

func (*Point) AffineY 

func (p *Point) AffineY() (*BaseFieldElement, error)

AffineY returns the affine y-coordinate.

func (*Point) Bytes 

func (p *Point) Bytes() []byte

Bytes returns the canonical byte encoding.

func (*Point) HashCode 

func (p *Point) HashCode() base.HashCode

HashCode returns a hash code for the receiver.

func (*Point) IsTorsionFree 

func (*Point) IsTorsionFree() bool

IsTorsionFree reports whether the point is torsion-free.

func (*Point) MarshalBinary 

func (p *Point) MarshalBinary() (data []byte, err error)

MarshalBinary implements encoding.BinaryMarshaler.

func (*Point) MarshalCBOR 

func (p *Point) MarshalCBOR() ([]byte, error)

MarshalCBOR implements cbor.Marshaler.

func (*Point) ScalarMul 

func (p *Point) ScalarMul(actor *Scalar) *Point

ScalarMul multiplies the point by a scalar.

func (*Point) ScalarOp 

func (p *Point) ScalarOp(sc *Scalar) *Point

ScalarOp adds a scalar multiple of q to the receiver.

func (*Point) String 

func (p *Point) String() string

String returns the string form of the receiver.

func (*Point) Structure 

func (*Point) Structure() algebra.Structure[*Point]

Structure returns the algebraic structure for the receiver.

func (*Point) ToCompressed 

func (p *Point) ToCompressed() []byte

ToCompressed encodes the point in compressed form.

func (*Point) ToUncompressed 

func (p *Point) ToUncompressed() []byte

ToUncompressed encodes the point in uncompressed form.

func (*Point) UnmarshalBinary 

func (p *Point) UnmarshalBinary(data []byte) error

UnmarshalBinary implements encoding.BinaryUnmarshaler.

func (*Point) UnmarshalCBOR 

func (p *Point) UnmarshalCBOR(data []byte) error

UnmarshalCBOR implements cbor.Unmarshaler.

type Scalar 

type Scalar struct {
	traits.PrimeFieldElementTrait[*p256Impl.Fq, p256Impl.Fq, *Scalar, Scalar]
}

Scalar represents a scalar field element.

func (*Scalar) MarshalBinary 

func (fe *Scalar) MarshalBinary() (data []byte, err error)

MarshalBinary implements encoding.BinaryMarshaler.

func (*Scalar) MarshalCBOR 

func (fe *Scalar) MarshalCBOR() ([]byte, error)

MarshalCBOR implements cbor.Marshaler.

func (*Scalar) Structure 

func (*Scalar) Structure() algebra.Structure[*Scalar]

Structure returns the algebraic structure for the receiver.

func (*Scalar) UnmarshalBinary 

func (fe *Scalar) UnmarshalBinary(data []byte) error

UnmarshalBinary implements encoding.BinaryUnmarshaler.

func (*Scalar) UnmarshalCBOR 

func (fe *Scalar) UnmarshalCBOR(data []byte) error

UnmarshalCBOR implements cbor.Unmarshaler.

type ScalarField 

type ScalarField struct {
	traits.PrimeFieldTrait[*p256Impl.Fq, *Scalar, Scalar]
}

ScalarField represents the scalar field.

func NewScalarField 

func NewScalarField() *ScalarField

NewScalarField returns the scalar field instance.

func (*ScalarField) BitLen 

func (*ScalarField) BitLen() int

BitLen returns the field modulus bit length.

func (*ScalarField) Characteristic 

func (*ScalarField) Characteristic() cardinal.Cardinal

Characteristic returns the field characteristic.

func (*ScalarField) ElementSize 

func (*ScalarField) ElementSize() int

ElementSize returns the element size in bytes.

func (*ScalarField) FromBytesBEReduce 

func (f *ScalarField) FromBytesBEReduce(input []byte) (*Scalar, error)

FromBytesBEReduce reduces a big-endian integer into the field.

func (*ScalarField) Hash 

func (*ScalarField) Hash(bytes []byte) (*Scalar, error)

Hash maps input bytes to an element or point.

func (*ScalarField) Name 

func (*ScalarField) Name() string

Name returns the name of the structure.

func (*ScalarField) Order 

func (*ScalarField) Order() cardinal.Cardinal

Order returns the group or field order.

func (*ScalarField) WideElementSize 

func (*ScalarField) WideElementSize() int

WideElementSize returns the wide element size in bytes.

Source Files

View all Source files

Directories

Path Synopsis
Package impl contains low-level P-256 field arithmetic and point operations.
 Package impl contains low-level P-256 field arithmetic and point operations.

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