Avoid session fixation attacks.

Rakefile

@@ -45,7 +45,7 @@ begin
     s.authors = ['José Valim', 'Carlos Antônio']
     s.files =  FileList["[A-Z]*", "{app,config,lib}/**/*"]
     s.extra_rdoc_files = FileList["[A-Z]*"] - %w(Gemfile Rakefile)
-    s.add_dependency("warden", "~> 0.10.7")
+    s.add_dependency("warden", "~> 1.0.2")
     s.add_dependency("bcrypt-ruby", "~> 2.1.2")
   end
 

lib/devise.rb

@@ -265,6 +265,11 @@ module Devise
     @@warden_config_block = block
   end
 
+  # Returns true if Rails version is bigger than 3.0.x
+  def self.rack_session?
+    Rails::VERSION::STRING[0,3] != "3.0"
+  end
+
   # A method used internally to setup warden manager from the Rails initialize
   # block.
   def self.configure_warden! #:nodoc:

lib/devise/controllers/helpers.rb

@@ -83,7 +83,7 @@ module Devise
       #
       def stored_location_for(resource_or_scope)
         scope = Devise::Mapping.find_scope!(resource_or_scope)
-        session.delete(:"#{scope}_return_to")
+        session.delete("#{scope}_return_to")
       end
 
       # The default url to be used after signing in. This is used by all Devise
@@ -114,7 +114,7 @@ module Devise
       #
       def after_sign_in_path_for(resource_or_scope)
         scope = Devise::Mapping.find_scope!(resource_or_scope)
-        home_path = :"#{scope}_root_path"
+        home_path = "#{scope}_root_path"
         respond_to?(home_path, true) ? send(home_path) : root_path
       end
 

lib/devise/rails/warden_compat.rb

@@ -36,4 +36,25 @@ class Warden::SessionSerializer
       raise
     end
   end
+end
+
+unless Devise.rack_session?
+  class ActionDispatch::Request
+    def reset_session
+      session.destroy if session && session.respond_to?(:destroy)
+      self.session = {}
+      @env['action_dispatch.request.flash_hash'] = nil
+    end
+  end
+
+  Warden::Manager.after_set_user :event => [:set_user, :authentication] do |record, warden, options|
+    if options[:scope] && warden.authenticated?(options[:scope])
+      request, flash = warden.request, warden.env['action_dispatch.request.flash_hash']
+      backup = request.session.to_hash
+      backup.delete("session_id")
+      request.reset_session
+      warden.env['action_dispatch.request.flash_hash'] = flash
+      request.session.update(backup)
+    end
+  end
 end

test/integration/authenticatable_test.rb

@@ -236,6 +236,17 @@ class AuthenticationSessionTest < ActionController::IntegrationTest
     get '/users'
     assert_equal "Cart", @controller.user_session[:cart]
   end
+
+  test 'session id is changed on sign in' do
+    get '/users'
+    session_id = request.session["session_id"]
+
+    get '/users'
+    assert_equal session_id, request.session["session_id"]
+
+    sign_in_as_user
+    assert_not_equal session_id, request.session["session_id"]
+  end
 end
 
 class AuthenticationWithScopesTest < ActionController::IntegrationTest