Sha256: bd5fec02b99f969e5848db4b2440b55382b3312d0fece61c1987d5bef23c8b5c
Contents?: true
Size: 1.04 KB
Versions: 9
Compression:
Stored size: 1.04 KB
Contents
require 'aead/cipher'
#
# Encrypt plaintext using the Galois Counter Mode of AES.
#
class AEAD::Cipher::AES_256_GCM < AEAD::Cipher
def self.key_len; 32; end
def self.iv_len; 12; end
def self.nonce_len; 12; end
def self.tag_len; 16; end
#
# Instantiates the cipher with a secret key.
#
# @param [String] key a secret encryption key
#
def initialize(key)
super('aes-256-gcm', key)
end
protected
def _encrypt(nonce, aad, plaintext)
self.cipher(:encrypt) do |cipher|
cipher.key = self.key
cipher.iv = nonce
cipher.aad = aad.to_s if aad
cipher.update(plaintext) + cipher.final + cipher.gcm_tag
end
end
def _decrypt(nonce, aad, ciphertext, tag)
self.cipher(:decrypt) do |cipher|
cipher.key = self.key
cipher.iv = nonce
cipher.gcm_tag = tag
cipher.aad = aad.to_s if aad
cipher.update(ciphertext).tap { cipher.verify }
end
rescue OpenSSL::Cipher::CipherError
raise ArgumentError, 'ciphertext failed authentication step'
end
end
Version data entries
9 entries across 9 versions & 1 rubygems