Added ActiveRecord::Base#has_secure_password (via ActiveModel::SecurePassword) to encapsulate dead-simple password usage with SHA2 encryption and salting

7 files changed, 148 insertions, 1 deletions

diff --git a/activemodel/CHANGELOG b/activemodel/CHANGELOG
index 4e963c77b0..a19d029217 100644
--- a/activemodel/CHANGELOG
+++ b/activemodel/CHANGELOG
@@ -1,15 +1,18 @@
 *Rails 3.1.0 (unreleased)*
 
-* No changes
+* Added ActiveModel::SecurePassword to encapsulate dead-simple password usage with SHA2 encryption and salting [DHH]
+
 
 *Rails 3.0.2 (unreleased)*
 
 * No changes
 
+
 *Rails 3.0.1 (October 15, 2010)*
 
 * No Changes, just a version bump.
 
+
 *Rails 3.0.0 (August 29, 2010)*
 
 * Added ActiveModel::MassAssignmentSecurity [Eric Chapweske, Josh Kalderimis]
diff --git a/activemodel/lib/active_model.rb b/activemodel/lib/active_model.rb
index be0f24ff92..dd6ee058cc 100644
--- a/activemodel/lib/active_model.rb
+++ b/activemodel/lib/active_model.rb
@@ -42,6 +42,7 @@ module ActiveModel
   autoload :Naming
   autoload :Observer, 'active_model/observing'
   autoload :Observing
+  autoload :SecurePassword
   autoload :Serialization
   autoload :TestCase
   autoload :Translation
diff --git a/activemodel/lib/active_model/secure_password.rb b/activemodel/lib/active_model/secure_password.rb
new file mode 100644
index 0000000000..0599ce6865
--- /dev/null
+++ b/activemodel/lib/active_model/secure_password.rb
@@ -0,0 +1,73 @@
+require 'digest/sha2'
+
+module ActiveModel
+  module SecurePassword
+    extend ActiveSupport::Concern
+
+    module ClassMethods
+      # Adds methods to set and authenticate against a SHA2-encrypted and salted password.
+      # This mechanism requires you to have password_digest and password_salt attributes.
+      # 
+      # Validations for presence of password, confirmation of password (using a "password_confirmation" attribute),
+      # and strength of password (at least 6 chars, not "password") are automatically added.
+      # You can add more validations by hand if need be.
+      #
+      # Example using Active Record (which automatically includes ActiveModel::SecurePassword):
+      #
+      #   # Schema: User(name:string, password_digest:string, password_salt:string)
+      #   class User < ActiveRecord::Base
+      #     has_secure_password
+      #   end
+      #
+      #   user = User.new(:name => "david", :password => "secret", :password_confirmation => "nomatch")
+      #   user.save                                                      # => false, password not long enough
+      #   user.password = "mUc3m00RsqyRe"                                
+      #   user.save                                                      # => false, confirmation doesn't match
+      #   user.password_confirmation = "mUc3m00RsqyRe"                   
+      #   user.save                                                      # => true
+      #   user.authenticate("notright")                                  # => false
+      #   user.authenticate("mUc3m00RsqyRe")                             # => user
+      #   User.find_by_name("david").try(:authenticate, "notright")      # => nil
+      #   User.find_by_name("david").try(:authenticate, "mUc3m00RsqyRe") # => user
+      def has_secure_password
+        attr_reader   :password
+        attr_accessor :password_confirmation
+
+        attr_protected(:password_digest, :password_salt) if respond_to?(:attr_protected)
+
+        validates_confirmation_of :password
+        validates_presence_of     :password_digest
+        validate                  :password_must_be_strong
+      end
+    end
+
+    module InstanceMethods
+      # Returns self if the password is correct, otherwise false.
+      def authenticate(unencrypted_password)
+        password_digest == encrypt_password(unencrypted_password) ? self : false
+      end
+
+      # Encrypts the password into the password_digest attribute.
+      def password=(unencrypted_password)
+        @password = unencrypted_password
+        self.password_digest = encrypt_password(unencrypted_password)
+      end
+
+      private
+        def salt_for_password
+          self.password_salt ||= self.object_id.to_s + rand.to_s
+        end
+
+        def encrypt_password(unencrypted_password)
+          Digest::SHA2.hexdigest(unencrypted_password + salt_for_password)
+        end
+        
+        def password_must_be_strong
+          if @password.present?
+            errors.add(:password, "must be longer than 6 characters") unless @password.size > 6
+            errors.add(:password, "can't be 'password'") if @password == "password"
+          end
+        end
+    end
+  end
+end
\ No newline at end of file
diff --git a/activemodel/test/cases/secure_password_test.rb b/activemodel/test/cases/secure_password_test.rb
new file mode 100644
index 0000000000..7d7c51e6cb
--- /dev/null
+++ b/activemodel/test/cases/secure_password_test.rb
@@ -0,0 +1,42 @@
+require 'cases/helper'
+require 'models/user'
+
+class SecurePasswordTest < ActiveModel::TestCase
+  setup do
+    @user = User.new
+  end
+
+  test "password must be present" do
+    assert !@user.valid?
+    assert_equal 1, @user.errors.size
+  end
+  
+  test "password must match confirmation" do
+    @user.password = "thiswillberight"
+    @user.password_confirmation = "wrong"
+    
+    assert !@user.valid?
+    
+    @user.password_confirmation = "thiswillberight"
+    
+    assert @user.valid?
+  end
+  
+  test "password must pass validation rules" do
+    @user.password = "password"
+    assert !@user.valid?
+    
+    @user.password = "short"
+    assert !@user.valid?
+    
+    @user.password = "plentylongenough"
+    assert @user.valid?
+  end
+  
+  test "authenticate" do
+    @user.password = "secret"
+    
+    assert !@user.authenticate("wrong")
+    assert @user.authenticate("secret")
+  end
+end
\ No newline at end of file
diff --git a/activemodel/test/models/user.rb b/activemodel/test/models/user.rb
new file mode 100644
index 0000000000..e221bb8091
--- /dev/null
+++ b/activemodel/test/models/user.rb
@@ -0,0 +1,8 @@
+class User
+  include ActiveModel::Validations
+  include ActiveModel::SecurePassword
+
+  has_secure_password
+
+  attr_accessor :password_digest, :password_salt
+end
diff --git a/activerecord/CHANGELOG b/activerecord/CHANGELOG
index 056de18cde..0f7e65e8cd 100644
--- a/activerecord/CHANGELOG
+++ b/activerecord/CHANGELOG
@@ -1,5 +1,24 @@
 *Rails 3.1.0 (unreleased)*
 
+* Added ActiveRecord::Base#has_secure_password (via ActiveModel::SecurePassword) to encapsulate dead-simple password usage with SHA2 encryption and salting [DHH]. Example:
+
+    # Schema: User(name:string, password_digest:string, password_salt:string)
+    class User < ActiveRecord::Base
+      has_secure_password
+    end
+    
+    user = User.new(:name => "david", :password => "secret", :password_confirmation => "nomatch")
+    user.save                                                      # => false, password not long enough
+    user.password = "mUc3m00RsqyRe"                                
+    user.save                                                      # => false, confirmation doesn't match
+    user.password_confirmation = "mUc3m00RsqyRe"                   
+    user.save                                                      # => true
+    user.authenticate("notright")                                  # => false
+    user.authenticate("mUc3m00RsqyRe")                             # => user
+    User.find_by_name("david").try(:authenticate, "notright")      # => nil
+    User.find_by_name("david").try(:authenticate, "mUc3m00RsqyRe") # => user
+
+
 * When a model is generated add_index is added by default for belongs_to or references columns 
 
   rails g model post user:belongs_to will generate the following:
diff --git a/activerecord/lib/active_record/base.rb b/activerecord/lib/active_record/base.rb
index d0f33c1d18..858ccebbfa 100644
--- a/activerecord/lib/active_record/base.rb
+++ b/activerecord/lib/active_record/base.rb
@@ -1851,6 +1851,7 @@ MSG
     include ActiveModel::MassAssignmentSecurity
     include Callbacks, ActiveModel::Observing, Timestamp
     include Associations, AssociationPreload, NamedScope
+    include ActiveModel::SecurePassword
 
     # AutosaveAssociation needs to be included before Transactions, because we want
     # #save_with_autosave_associations to be wrapped inside a transaction.