Class: ActiveSupport::MessageEncryptor

Inherits:
Object
  • Object
show all
Defined in:
activesupport/lib/active_support/message_encryptor.rb

Overview

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.

Defined Under Namespace

Classes: InvalidMessage

Constant Summary collapse

OpenSSLCipherError = 
OpenSSL::Cipher.const_defined?(:CipherError) ? OpenSSL::Cipher::CipherError : OpenSSL::CipherError

Instance Method Summary collapse

Constructor Details

#initialize(secret, cipher = 'aes-256-cbc') ⇒ MessageEncryptor

Returns a new instance of MessageEncryptor.



16
17
18
19
 
# File 'activesupport/lib/active_support/message_encryptor.rb', line 16

def initialize(secret, cipher = 'aes-256-cbc')
  @secret = secret
  @cipher = cipher
end

Instance Method Details

#decrypt(encrypted_message) ⇒ Object 



36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
 
# File 'activesupport/lib/active_support/message_encryptor.rb', line 36

def decrypt(encrypted_message)
  cipher = new_cipher
  encrypted_data, iv = encrypted_message.split("--").map {|v| ActiveSupport::Base64.decode64(v)}

  cipher.decrypt
  cipher.key = @secret
  cipher.iv  = iv

  decrypted_data = cipher.update(encrypted_data)
  decrypted_data << cipher.final

  Marshal.load(decrypted_data)
rescue OpenSSLCipherError, TypeError
  raise InvalidMessage
end

#decrypt_and_verify(value) ⇒ Object 



56
57
58
 
# File 'activesupport/lib/active_support/message_encryptor.rb', line 56

def decrypt_and_verify(value)
  decrypt(verifier.verify(value))
end

#encrypt(value) ⇒ Object 



21
22
23
24
25
26
27
28
29
30
31
32
33
34
 
# File 'activesupport/lib/active_support/message_encryptor.rb', line 21

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(Marshal.dump(value))
  encrypted_data << cipher.final

  [encrypted_data, iv].map {|v| ActiveSupport::Base64.encode64s(v)}.join("--")
end

#encrypt_and_sign(value) ⇒ Object 



52
53
54
 
# File 'activesupport/lib/active_support/message_encryptor.rb', line 52

def encrypt_and_sign(value)
  verifier.generate(encrypt(value))
end