package crypto

import "io"

// KEM defines the contract for a Key Encapsulation Mechanism.
type KEM interface {
	SchemeID() uint16
	GenerateKeyPair(
		rand io.Reader,
	) (
		RecipientPub,
		RecipientPriv,
		error,
	)
	Encapsulate(
		pub RecipientPub,
		rand io.Reader,
	) (
		ciphertext []byte,
		sharedSecret []byte,
		err error,
	)
	Decapsulate(
		priv RecipientPriv,
		ciphertext []byte,
	) (
		sharedSecret []byte,
		err error,
	)
	LoadPriv(
		raw []byte,
	) (
		RecipientPriv,
		error,
	)
}

// RecipientPub represents a public recipient key.
type RecipientPub interface {
	SchemeID() uint16
	KeyID() []byte
	Raw() []byte
}

// RecipientPriv represents a private recipient key.
type RecipientPriv interface {
	SchemeID() uint16
	KeyID() []byte
	Raw() []byte
}