vrf

Documentation

Overview

Package p256 implements a verifiable random function using curve p256.

Index

• Variables
• func GenerateKey() (*PrivateKey, *PublicKey)
• func H1(m []byte) (x, y *big.Int)
• func H2(m []byte) *big.Int
• func Unmarshal(curve elliptic.Curve, data []byte) (x, y *big.Int)
• type Output
• type PrivateKey
  • func (k PrivateKey) Evaluate(m []byte) (index [32]byte, proof []byte)
  • func (k PrivateKey) Public() crypto.PublicKey
• type Proof
• type PublicKey
  • func (pk *PublicKey) ProofToHash(m, proof []byte) (index [32]byte, err error)

Variables

var (

	// ErrPointNotOnCurve occurs when a public key is not on the curve.
	ErrPointNotOnCurve = errors.New("point is not on the S256 curve")
	// ErrWrongKeyType occurs when a key is not an ECDSA key.
	ErrWrongKeyType = errors.New("not an ECDSA key")
	// ErrNoPEMFound occurs when attempting to parse a non PEM data structure.
	ErrNoPEMFound = errors.New("no PEM block found")
	// ErrInvalidVRF occurs when the VRF does not validate.
	ErrInvalidVRF = errors.New("invalid VRF proof")
)

Functions

func GenerateKey

func GenerateKey() (*PrivateKey, *PublicKey)

GenerateKey generates a fresh keypair for this VRF

func H1

func H1(m []byte) (x, y *big.Int)

H1 hashes m to a curve point

func H2

func H2(m []byte) *big.Int

H2 hashes to an integer [1,N-1]

func Unmarshal

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

Unmarshal a compressed point in the form specified in section 4.3.6 of ANSI X9.62.

Types

type Output

type Output [32]byte

type PrivateKey

type PrivateKey struct {
	*ecdsa.PrivateKey
}

PrivateKey holds a private VRF key.

func (PrivateKey) Evaluate

func (k PrivateKey) Evaluate(m []byte) (index [32]byte, proof []byte)

Evaluate returns the verifiable unpredictable function evaluated at m

func (PrivateKey) Public

func (k PrivateKey) Public() crypto.PublicKey

Public returns the corresponding public key as bytes.

type Proof

type Proof []byte

type PublicKey

type PublicKey struct {
	*ecdsa.PublicKey
}

PublicKey holds a public VRF key.

func (*PublicKey) ProofToHash

func (pk *PublicKey) ProofToHash(m, proof []byte) (index [32]byte, err error)

ProofToHash asserts that proof is correct for m and outputs index.