ecdh

Documentation

Overview

Package ecdh implements the Diffie-Hellman key exchange with elliptic curves. This package directly implements generic curves imlementing elliptic.Curve (the NIST curves P224, P256, P384 and P521) and Bernstein's Curve25519. Other curves can be used by implementing the KeyExchange interface.

For generic curves this implementation of ECDH only uses the x-coordinate as the computed secret.

Index

• type KeyExchange
  • func Curve25519() KeyExchange
  • func GenericCurve(c elliptic.Curve) KeyExchange
• type PrivateKey
• type PublicKey

Types

type KeyExchange

type KeyExchange interface {
	// GenerateKey generates a private/public key pair using entropy from rand.
	// If rand is nil, crypto/rand.Reader will be used.
	GenerateKey(rand io.Reader) (private PrivateKey, public PublicKey, err error)

	// PublicKey returns the public key corresponding to the given private one.
	PublicKey(private PrivateKey) (public PublicKey)

	// Check returns a non-nil error if the peers public key cannot used for the
	// key exchange (e.g. the public key isn't a point of the elliptic curve)
	// It's recommended to check peer's public key before computing the secret.
	Check(peersPublic PublicKey) (err error)

	// ComputeSecret returns the secret value computed from the given private key
	// and the peers public key.
	ComputeSecret(private PrivateKey, peersPublic PublicKey) (secret []byte)
}

KeyExchange is the interface defining all functions necessary for ECDH.

func Curve25519

func Curve25519() KeyExchange

Curve25519 creates a new ecdh.KeyExchange with the elliptic curve Curve25519.

func GenericCurve

func GenericCurve(c elliptic.Curve) KeyExchange

GenericCurve creates a new ecdh.KeyExchange with generic elliptic.Curve implementations.

type PrivateKey

type PrivateKey []byte

PrivateKey is the type of ECDH private keys.

type PublicKey

type PublicKey []byte

PublicKey is the type of ECDH public keys.