MessageEncryptor is a simple way to encrypt values which get stored somewhere you don't trust.
The cipher text and initialization vector are base64 encoded and returned to you.
This can be used in situations similar to the MessageVerifier
,
but where you don't want users to be able to determine the value of the
payload.
# File lib/active_support/message_encryptor.rb, line 26 def initialize(secret, options = {}) unless options.is_a?(Hash) ActiveSupport::Deprecation.warn "The second parameter should be an options hash. Use :cipher => 'algorithm' to specify the cipher algorithm." options = { :cipher => options } end @secret = secret @cipher = options[:cipher] || 'aes-256-cbc' @verifier = MessageVerifier.new(@secret, :serializer => NullSerializer) @serializer = options[:serializer] || Marshal end
# File lib/active_support/message_encryptor.rb, line 44 def decrypt(value) ActiveSupport::Deprecation.warn "MessageEncryptor#decrypt is deprecated as it is not safe without a signature. " "Please use MessageEncryptor#decrypt_and_verify instead." _decrypt(value) end
Decrypt and verify a message. We need to verify the message in order to avoid padding attacks. Reference: www.limited-entropy.com/padding-oracle-attacks
# File lib/active_support/message_encryptor.rb, line 58 def decrypt_and_verify(value) _decrypt(verifier.verify(value)) end
# File lib/active_support/message_encryptor.rb, line 38 def encrypt(value) ActiveSupport::Deprecation.warn "MessageEncryptor#encrypt is deprecated as it is not safe without a signature. " "Please use MessageEncryptor#encrypt_and_sign instead." _encrypt(value) end
Encrypt and sign a message. We need to sign the message in order to avoid padding attacks. Reference: www.limited-entropy.com/padding-oracle-attacks
# File lib/active_support/message_encryptor.rb, line 52 def encrypt_and_sign(value) verifier.generate(_encrypt(value)) end
# File lib/active_support/message_encryptor.rb, line 79 def _decrypt(encrypted_message) cipher = new_cipher encrypted_data, iv = encrypted_message.split("--").map {|v| ::Base64.decode64(v)} cipher.decrypt cipher.key = @secret cipher.iv = iv decrypted_data = cipher.update(encrypted_data) decrypted_data << cipher.final @serializer.load(decrypted_data) rescue OpenSSLCipherError, TypeError raise InvalidMessage end
# File lib/active_support/message_encryptor.rb, line 64 def _encrypt(value) cipher = new_cipher # Rely on OpenSSL for the initialization vector iv = cipher.random_iv cipher.encrypt cipher.key = @secret cipher.iv = iv encrypted_data = cipher.update(@serializer.dump(value)) encrypted_data << cipher.final [encrypted_data, iv].map {|v| ::Base64.strict_encode64(v)}.join("--") end
# File lib/active_support/message_encryptor.rb, line 95 def new_cipher OpenSSL::Cipher::Cipher.new(@cipher) end
# File lib/active_support/message_encryptor.rb, line 99 def verifier @verifier end