ecdh

Documentation

Index

• Variables
• func DeriveSharedSecret(ours EphemeralKeyPair, theirs PeerPublicKey) ([]byte, error)
• type EphemeralKeyPair
  • func NewEphemeralKeyPair() EphemeralKeyPair
• type PeerPublicKey
• type PeerType

Variables

var (
	ErrInvalidPeerType = errors.New("invalid peer type")
)

Functions

func DeriveSharedSecret

func DeriveSharedSecret(ours EphemeralKeyPair, theirs PeerPublicKey) ([]byte, error)

Derives a 64-byte shared secret given one party's ephemeral keypair and another party's ephemeral public key obtained from ECDH.

The secret is computed using the following KDF (similar to libsodium):

blake2b-512(q || client-pub || server-pub).

where q is the 32-byte x25519 shared secret.

The client and server's public keys must be ordered the same way on both sides, so the peer's type (client or server) must be provided along with the peer's public key.

Types

type EphemeralKeyPair

type EphemeralKeyPair struct {
	PrivateKey []byte
	PublicKey  []byte
}

func NewEphemeralKeyPair

func NewEphemeralKeyPair() EphemeralKeyPair

Creates a new x25519 keypair for use in ECDH key exchange.

type PeerPublicKey

type PeerPublicKey struct {
	PublicKey []byte
	PeerType  PeerType
}

type PeerType

type PeerType int

const (
	PeerTypeClient PeerType = iota
	PeerTypeServer
)