Adding SHA256 as a crypto provider

lib/authlogic.rb

@@ -11,6 +11,7 @@
 
 require File.dirname(__FILE__) + "/authlogic/crypto_providers/md5"
 require File.dirname(__FILE__) + "/authlogic/crypto_providers/sha1"
+require File.dirname(__FILE__) + "/authlogic/crypto_providers/sha256"
 require File.dirname(__FILE__) + "/authlogic/crypto_providers/sha512"
 require File.dirname(__FILE__) + "/authlogic/crypto_providers/bcrypt"
 require File.dirname(__FILE__) + "/authlogic/crypto_providers/aes256"

lib/authlogic/crypto_providers/sha256.rb

@@ -0,0 +1,50 @@
+require "digest/sha2"
+
+module Authlogic
+  # The acts_as_authentic method has a crypto_provider option. This allows you to use any type of encryption you like.
+  # Just create a class with a class level encrypt and matches? method. See example below.
+  #
+  # === Example
+  #
+  #   class MyAwesomeEncryptionMethod
+  #     def self.encrypt(*tokens)
+  #       # the tokens passed will be an array of objects, what type of object is irrelevant,
+  #       # just do what you need to do with them and return a single encrypted string.
+  #       # for example, you will most likely join all of the objects into a single string and then encrypt that string
+  #     end
+  #
+  #     def self.matches?(crypted, *tokens)
+  #       # return true if the crypted string matches the tokens.
+  #       # depending on your algorithm you might decrypt the string then compare it to the token, or you might
+  #       # encrypt the tokens and make sure it matches the crypted string, its up to you
+  #     end
+  #   end
+  module CryptoProviders
+    # = Sha256
+    #
+    # Uses the Sha256 hash algorithm to encrypt passwords.
+    class Sha256
+      class << self
+        attr_accessor :join_token
+
+        # The number of times to loop through the encryption. This is ten because that is what restful_authentication defaults to.
+        def stretches
+          @stretches ||= 20
+        end
+        attr_writer :stretches
+
+        # Turns your raw password into a Sha256 hash.
+        def encrypt(*tokens)
+          digest = tokens.flatten.join(join_token)
+          stretches.times { digest = Digest::SHA256.hexdigest(digest) }
+          digest
+        end
+
+        # Does the crypted password match the tokens? Uses the same tokens that were used to encrypt.
+        def matches?(crypted, *tokens)
+          encrypt(*tokens) == crypted
+        end
+      end
+    end
+  end
+end

test/crypto_provider_test/sha256_test.rb

@@ -0,0 +1,14 @@
+require File.dirname(__FILE__) + '/../test_helper.rb'
+
+module CryptoProviderTest
+  class Sha256Test < ActiveSupport::TestCase
+    def test_encrypt
+      assert Authlogic::CryptoProviders::Sha256.encrypt("mypass")
+    end
+
+    def test_matches
+      hash = Authlogic::CryptoProviders::Sha256.encrypt("mypass")
+      assert Authlogic::CryptoProviders::Sha256.matches?(hash, "mypass")
+    end
+  end
+end