xaes256gcm

README

import "filippo.io/xaes256gcm"

Package xaes256gcm implements the XAES-256-GCM extended-nonce AEAD, an efficient combination of a NIST SP 800-108r1 KDF and AES-256-GCM.

Documentation

Overview

Package xaes256gcm implements the XAES-256-GCM extended-nonce AEAD, an efficient combination of a NIST SP 800-108r1 KDF and AES-256-GCM.

Index

• Constants
• func NewWithManualNonces(key []byte) (cipher.AEAD, error)

Constants

const KeySize = 32

KeySize is the size of XAES-256-GCM keys.

const NonceSize = 24

NonceSize is the size of nonces that must be passed to Seal and Open, if the AEAD was created with NewWithManualNonces.

const Overhead = 40

Overhead is the difference between the lengths of a plaintext and its ciphertext, if the AEAD was created with [New]. It includes the length of the randomly-generated and automatically-managed nonce.

const OverheadWithManualNonces = 16

OverheadWithManualNonces is the difference between the lengths of a plaintext and its ciphertext, if the AEAD was created with NewWithManualNonces.

Functions

func NewWithManualNonces

func NewWithManualNonces(key []byte) (cipher.AEAD, error)

NewWithManualNonces returns a new XAES-256-GCM instance that expects 24-byte nonces to be passed to Open and Seal. nonces can be safely generated with crypto/rand.Read. key must be exactly 32 bytes long.

Most applications should use [New] instead, which automatically generates random nonces and prepends them to the ciphertext. (Note that New is not implemented yet.)