class ActiveSupport::KeyGenerator - activesupport-4.2.3 Documentation

# class ActiveSupport::KeyGenerator

KeyGenerator is a simple wrapper around OpenSSL's implementation of PBKDF2 It can be used to derive a number of keys for various purposes from a given secret. This lets Rails applications have a single secure secret, but avoid reusing that key in multiple incompatible contexts.

### Public Class Methods

new(secret, options = {}) click to toggle source

    # File lib/active_support/key_generator.rb, line 10
    def initialize(secret, options = {})
      @secret = secret
      # The default iterations are higher than required for our key derivation uses
      # on the off chance someone uses this for password storage
      @iterations = options[:iterations] || 2**16
    end

### Public Instance Methods

generate_key(salt, key_size=64) click to toggle source

Returns a derived key suitable for use. The default key_size is chosen to be compatible with the default settings of ActiveSupport::MessageVerifier. i.e. OpenSSL::Digest::SHA1#block_length

    # File lib/active_support/key_generator.rb, line 20
    def generate_key(salt, key_size=64)
      OpenSSL::PKCS5.pbkdf2_hmac_sha1(@secret, salt, @iterations, key_size)
    end