cipher

type API interface {
	// Seal returns an authenticated and encrypted version of the supplied
	// data. Seal appends the encrypted data to the supplied buf and the
	// the returned slice points to the newly encrypted data that can be used
	// as the argument to Open (it includes he MAC).
	Seal(buf, data []byte) ([]byte, error)

	// Open authenticates and decrypts a box produced by Seal and returns true
	// on success. The decrypted data is appended to buf and the returned slice
	// points to the newly decrypted data.
	Open(buf, data []byte) ([]byte, bool)

	// ChannelBinding Returns a byte slice that is unique for the the
	// particular cipher (and the parties between which it is operating).
	// Having both parties assert out of the band that they are indeed
	// participating in a connection with that channel binding value is
	// sufficient to authenticate the data received through the cipher.
	ChannelBinding() []byte

	// Overhead is the max difference between the plaintext and ciphertext sizes.
	Overhead() int
}