version: 1.10

## package elliptic

import "crypto/elliptic"

## Overview

Package elliptic implements several standard elliptic curves over prime fields.

## func GenerateKey¶

func GenerateKey(curve Curve, rand io.Reader) (priv []byte, x, y *big.Int, err error)

GenerateKey returns a public/private key pair. The private key is generated
using the given reader, which must return random data.

## func Marshal¶

func Marshal(curve Curve, x, y *big.Int) []byte

Marshal converts a point into the uncompressed form specified in section 4.3.6
of ANSI X9.62.

## func Unmarshal¶

func Unmarshal(curve Curve, data []byte) (x, y *big.Int)

Unmarshal converts a point, serialized by Marshal, into an x, y pair. It is an
error if the point is not in uncompressed form or is not on the curve. On error,
x = nil.

## type Curve¶

type Curve interface {    // Params returns the parameters for the curve.    Params() *CurveParams    // IsOnCurve reports whether the given (x,y) lies on the curve.    IsOnCurve(x, y *big.Int) bool    // Add returns the sum of (x1,y1) and (x2,y2)    Add(x1, y1, x2, y2 *big.Int) (x, y *big.Int)    // Double returns 2*(x,y)    Double(x1, y1 *big.Int) (x, y *big.Int)    // ScalarMult returns k*(Bx,By) where k is a number in big-endian form.    ScalarMult(x1, y1 *big.Int, k []byte) (x, y *big.Int)    // ScalarBaseMult returns k*G, where G is the base point of the group    // and k is an integer in big-endian form.    ScalarBaseMult(k []byte) (x, y *big.Int)}

A Curve represents a short-form Weierstrass curve with a=-3. See
http://www.hyperelliptic.org/EFD/g1p/auto-shortw.html

### func P224¶

func P224() Curve

P224 returns a Curve which implements P-224 (see FIPS 186-3, section D.2.2).

The cryptographic operations are implemented using constant-time algorithms.

### func P256¶

func P256() Curve

P256 returns a Curve which implements P-256 (see FIPS 186-3, section D.2.3)

The cryptographic operations are implemented using constant-time algorithms.

### func P384¶

func P384() Curve

P384 returns a Curve which implements P-384 (see FIPS 186-3, section D.2.4)

The cryptographic operations do not use constant-time algorithms.

### func P521¶

func P521() Curve

P521 returns a Curve which implements P-521 (see FIPS 186-3, section D.2.5)

The cryptographic operations do not use constant-time algorithms.

## type CurveParams¶

type CurveParams struct {    P       *big.Int // the order of the underlying field    N       *big.Int // the order of the base point    B       *big.Int // the constant of the curve equation    Gx, Gy  *big.Int // (x,y) of the base point    BitSize int      // the size of the underlying field    Name    string   // the canonical name of the curve}

CurveParams contains the parameters of an elliptic curve and also provides a
generic, non-constant time implementation of Curve.

func (curve *CurveParams) Add(x1, y1, x2, y2 *big.Int) (*big.Int, *big.Int)

### func (*CurveParams) Double¶

func (curve *CurveParams) Double(x1, y1 *big.Int) (*big.Int, *big.Int)

### func (*CurveParams) IsOnCurve¶

func (curve *CurveParams) IsOnCurve(x, y *big.Int) bool

### func (*CurveParams) Params¶

func (curve *CurveParams) Params() *CurveParams

### func (*CurveParams) ScalarBaseMult¶

func (curve *CurveParams) ScalarBaseMult(k []byte) (*big.Int, *big.Int)

### func (*CurveParams) ScalarMult¶

func (curve *CurveParams) ScalarMult(Bx, By *big.Int, k []byte) (*big.Int, *big.Int)