Merge csrf_killer plugin into rails. Adds RequestForgeryProtection model that verifies session-specific _tokens for non-GET requests. [Rick]

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@7592 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

actionpack/CHANGELOG

@@ -1,5 +1,7 @@
 *SVN*
 
+* Merge csrf_killer plugin into rails.  Adds RequestForgeryProtection model that verifies session-specific _tokens for non-GET requests.  [Rick]
+
 * Secure #sanitize, #strip_tags, and #strip_links helpers against xss attacks.  Closes #8877. [Rick, lifofifo, Jacques Distler]
 
   This merges and renames the popular white_list helper (along with some css sanitizing from Jacques Distler version of the same plugin).

actionpack/lib/action_controller.rb

@@ -54,6 +54,7 @@ require 'action_controller/session_management'
 require 'action_controller/http_authentication'
 require 'action_controller/components'
 require 'action_controller/record_identifier'
+require 'action_controller/request_forgery_protection'
 
 require 'action_view'
 ActionController::Base.template_class = ActionView::Base
@@ -74,4 +75,5 @@ ActionController::Base.class_eval do
   include ActionController::HttpAuthentication::Basic::ControllerMethods
   include ActionController::Components
   include ActionController::RecordIdentifier
+  include ActionController::RequestForgeryProtection
 end

actionpack/lib/action_controller/base.rb

@@ -326,6 +326,10 @@ module ActionController #:nodoc:
     # Controls the resource action separator
     @@resource_action_separator = "/"
     cattr_accessor :resource_action_separator
+    
+    # Sets the token parameter name for RequestForgery.  Calling #verify_token sets it to :_token by default
+    @@request_forgery_protection_token = nil
+    cattr_accessor :request_forgery_protection_token
 
     # Holds the request object that's primarily used to get environment variables through access like
     # <tt>request.env["REQUEST_URI"]</tt>.

actionpack/lib/action_controller/request_forgery_protection.rb

@@ -0,0 +1,75 @@
+module ActionController #:nodoc:
+  class InvalidToken < ActionControllerError; end
+
+  # Protect a controller's actions with the #verify_token method.  Failure to validate will result in a ActionController::InvalidToken 
+  # exception.  Customize the error message through the use of rescue_templates and rescue_action_in_public.
+  #
+  #   class FooController < ApplicationController
+  #     # uses the cookie session store
+  #     verify_token :except => :index
+  #
+  #     # uses one of the other session stores that uses a session_id value.
+  #     verify_token :secret => 'my-little-pony', :except => :index
+  #   end
+  #
+  # Valid Options:
+  #
+  # * <tt>:only/:except</tt> - passed to the before_filter call.  Set which actions are verified.
+  # * <tt>:secret</tt> - Custom salt used to generate the form_token.  Leave this off if you are using the cookie session store.
+  # * <tt>:digest</tt> - Message digest used for hashing.  Defaults to 'SHA1'
+  module RequestForgeryProtection
+    def self.included(base)
+      base.class_eval do
+        class_inheritable_accessor :verify_token_options
+        self.verify_token_options = {}
+        helper_method :form_token
+      end
+      base.extend(ClassMethods)
+    end
+    
+    module ClassMethods
+      def verify_token(options = {})
+        self.request_forgery_protection_token ||= :_token
+        before_filter :verify_request_token, :only => options.delete(:only), :except => options.delete(:except)
+        verify_token_options.update(options)
+      end
+    end
+
+    protected
+      # The actual before_filter that is used.  Modify this to change how you handle unverified requests.
+      def verify_request_token
+        verified_request? || raise(ActionController::InvalidToken)
+      end
+      
+      # Returns true or false if a request is verified.  Checks:
+      #
+      # * is the format restricted?  By default, only HTML and AJAX requests are checked.
+      # * is it a GET request?  Gets should be safe and idempotent
+      # * Does the form_token match the given _token value from the params?
+      def verified_request?
+        request_forgery_protection_token.nil? || request.method == :get || !verifiable_request_format? || form_token == params[request_forgery_protection_token]
+      end
+    
+      def verifiable_request_format?
+        request.format.html? || request.format.js?
+      end
+    
+      # Sets the token value for the current session.  Pass a :secret option in #verify_token to add a custom salt to the hash.
+      def form_token
+        @form_token ||= verify_token_options[:secret] ? token_from_session_id : token_from_cookie_session
+      end
+      
+      # Generates a unique digest using the session_id and the CSRF secret.
+      def token_from_session_id
+        key    = verify_token_options[:secret].respond_to?(:call) ? verify_token_options[:secret].call(@session) : verify_token_options[:secret]
+        digest = verify_token_options[:digest] || 'SHA1'
+        OpenSSL::HMAC.hexdigest(OpenSSL::Digest::Digest.new(digest), key.to_s, session.session_id.to_s)
+      end
+      
+      # No secret was given, so assume this is a cookie session store.
+      def token_from_cookie_session
+        session[:csrf_id] ||= CGI::Session.generate_unique_id
+        session.dbman.generate_digest(session[:csrf_id])
+      end
+  end
+end

actionpack/lib/action_controller/rescue.rb

@@ -20,7 +20,8 @@ module ActionController #:nodoc:
       'ActiveRecord::RecordInvalid'        => :unprocessable_entity,
       'ActiveRecord::RecordNotSaved'       => :unprocessable_entity,
       'ActionController::MethodNotAllowed' => :method_not_allowed,
-      'ActionController::NotImplemented'   => :not_implemented
+      'ActionController::NotImplemented'   => :not_implemented,
+      'ActionController::InvalidToken'     => :unprocessable_entity
     }
 
     DEFAULT_RESCUE_TEMPLATE = 'diagnostics'

actionpack/lib/action_view/base.rb

@@ -328,6 +328,8 @@ module ActionView #:nodoc:
       @@sanitized_allowed_protocols.merge(attributes)
     end
 
+    delegate :request_forgery_protection_token, :to => :controller
+
     @@template_handlers = HashWithIndifferentAccess.new
  
     module CompiledTemplates #:nodoc:

actionpack/lib/action_view/helpers/form_tag_helper.rb

@@ -401,10 +401,10 @@ module ActionView
               ''
             when /^post$/i, "", nil
               html_options["method"] = "post"
-              ''
+              request_forgery_protection_token ? content_tag(:div, token_tag, :style => 'margin:0;padding:0') : ''
             else
               html_options["method"] = "post"
-              content_tag(:div, tag(:input, :type => "hidden", :name => "_method", :value => method), :style => 'margin:0;padding:0')
+              content_tag(:div, tag(:input, :type => "hidden", :name => "_method", :value => method) + token_tag, :style => 'margin:0;padding:0')
           end
         end
         
@@ -419,6 +419,14 @@ module ActionView
           concat(content, block.binding)
           concat("</form>", block.binding)
         end
+
+        def token_tag
+          if request_forgery_protection_token.nil?
+            ''
+          else
+            tag(:input, :type => "hidden", :name => request_forgery_protection_token.to_s, :value => form_token)
+          end
+        end
     end
   end
 end

actionpack/lib/action_view/helpers/prototype_helper.rb

@@ -738,6 +738,15 @@ module ActionView
         elsif options[:with]
           js_options['parameters'] = options[:with]
         end
+        
+        if request_forgery_protection_token
+          if js_options['parameters']
+            js_options['parameters'] << " + '&"
+          else
+            js_options['parameters'] = "'"
+          end
+          js_options['parameters'] << "_token=' + encodeURIComponent('#{escape_javascript form_token}')"
+        end
       
         options_for_javascript(js_options)
       end

actionpack/lib/action_view/helpers/text_helper.rb

@@ -325,15 +325,15 @@ module ActionView
       #   strip_links('Blog: <a href="http://www.myblog.com/" class="nav" target=\"_blank\">Visit</a>.')
       #   # => Blog: Visit
       def strip_links(html)
-        # Stupid firefox treats '<href="http://whatever.com" onClick="alert()">something' as link! 
-        if html.index("<a") || html.index("<href")   
-          tokenizer = HTML::Tokenizer.new(html) 
-          result = ''
-          while token = tokenizer.next 
-            node = HTML::Node.parse(nil, 0, 0, token, false) 
-            result << node.to_s unless node.is_a?(HTML::Tag) && ["a", "href"].include?(node.name) 
-          end 
-          strip_links(result) # Recurse - handle all dirty nested links
+        if !html.blank? && html.index("<a") || html.index("<href")
+          tokenizer = HTML::Tokenizer.new(html)
+          result = returning [] do |result|
+            while token = tokenizer.next 
+              node = HTML::Node.parse(nil, 0, 0, token, false) 
+              result << node.to_s unless node.is_a?(HTML::Tag) && ["a", "href"].include?(node.name) 
+            end 
+          end
+          strip_links(result.join) # Recurse - handle all dirty nested links
         else
           html
         end
@@ -441,6 +441,7 @@ module ActionView
       # that of html-scanner.
       #
       # ==== Examples
+      #
       #   strip_tags("Strip <i>these</i> tags!")
       #   # => Strip these tags!
       #
@@ -450,22 +451,21 @@ module ActionView
       #   strip_tags("<div id='top-bar'>Welcome to my website!</div>")
       #   # => Welcome to my website!
       def strip_tags(html)     
-        return html if html.blank?
-        if html.index("<")
-          text = ""
-          tokenizer = HTML::Tokenizer.new(html)
+        return html if html.blank? || !html.index("<")
+        tokenizer = HTML::Tokenizer.new(html)
 
+        text = returning [] do |text|
           while token = tokenizer.next
             node = HTML::Node.parse(nil, 0, 0, token, false)
             # result is only the content of any Text nodes
             text << node.to_s if node.class == HTML::Text  
           end
-          # strip any comments, and if they have a newline at the end (ie. line with
-          # only a comment) strip that too
-          strip_tags(text.gsub(/<!--(.*?)-->[\n]?/m, "")) # Recurse - handle all dirty nested tags
-        else
-          html # already plain text
-        end 
+        end
+        
+        # strip any comments, and if they have a newline at the end (ie. line with
+        # only a comment) strip that too
+        # Recurse - handle all dirty nested tags
+        strip_tags(text.join.gsub(/<!--(.*?)-->[\n]?/m, ""))
       end
       
       # Creates a Cycle object whose _to_s_ method cycles through elements of an

actionpack/lib/action_view/helpers/url_helper.rb

@@ -472,6 +472,10 @@ module ActionView
             submit_function << "m.setAttribute('name', '_method'); m.setAttribute('value', '#{method}'); f.appendChild(m);"
           end
 
+          if request_forgery_protection_token
+            submit_function << "var s = document.createElement('input'); s.setAttribute('type', 'hidden'); "
+            submit_function << "s.setAttribute('name', '_token'); s.setAttribute('value', '#{escape_javascript form_token}'); f.appendChild(s);"
+          end
           submit_function << "f.submit();"
         end
 

actionpack/test/controller/request_forgery_protection_test.rb

@@ -0,0 +1,217 @@
+require File.dirname(__FILE__) + '/../abstract_unit'
+
+ActionController::Routing::Routes.draw do |map|
+  map.connect ':controller/:action/:id'
+end
+
+class RequestForgeryProtectionController < ActionController::Base
+  verify_token :only => :index, :secret => 'abc'
+
+  def index
+    render :inline => "<%= form_tag('/') {} %>"
+  end
+  
+  def unsafe
+    render :text => 'pwn'
+  end
+  
+  def rescue_action(e) raise e end
+end
+
+class RequestForgeryProtectionControllerTest < Test::Unit::TestCase
+  def setup
+    @controller = RequestForgeryProtectionController.new
+    @request    = ActionController::TestRequest.new
+    @response   = ActionController::TestResponse.new
+    class << @request.session
+      def session_id() '123' end
+    end
+    @token = OpenSSL::HMAC.hexdigest(OpenSSL::Digest::Digest.new('SHA1'), 'abc', '123')
+    ActionController::Base.request_forgery_protection_token = :_token
+  end
+  
+  def teardown
+    ActionController::Base.request_forgery_protection_token = nil
+  end
+
+  def test_should_render_form_with_token_tag
+    get :index
+    assert_select 'form>div>input[name=?][value=?]', '_token', @token
+  end
+
+  # Replace this with your real tests.
+  def test_should_allow_get
+    get :index
+    assert_response :success
+  end
+  
+  def test_should_allow_post_without_token_on_unsafe_action
+    post :unsafe
+    assert_response :success
+  end
+  
+  def test_should_not_allow_post_without_token
+    assert_raises(ActionController::InvalidToken) { post :index }
+  end
+  
+  def test_should_not_allow_put_without_token
+    assert_raises(ActionController::InvalidToken) { put :index }
+  end
+  
+  def test_should_not_allow_delete_without_token
+    assert_raises(ActionController::InvalidToken) { delete :index }
+  end
+  
+  def test_should_not_allow_xhr_post_without_token
+    assert_raises(ActionController::InvalidToken) { xhr :post, :index }
+  end
+  
+  def test_should_not_allow_xhr_put_without_token
+    assert_raises(ActionController::InvalidToken) { xhr :put, :index }
+  end
+  
+  def test_should_not_allow_xhr_delete_without_token
+    assert_raises(ActionController::InvalidToken) { xhr :delete, :index }
+  end
+  
+  def test_should_allow_post_with_token
+    post :index, :_token => @token
+    assert_response :success
+  end
+  
+  def test_should_allow_put_with_token
+    put :index, :_token => @token
+    assert_response :success
+  end
+  
+  def test_should_allow_delete_with_token
+    delete :index, :_token => @token
+    assert_response :success
+  end
+  
+  def test_should_allow_post_with_xml
+    post :index, :format => 'xml'
+    assert_response :success
+  end
+  
+  def test_should_allow_put_with_xml
+    put :index, :format => 'xml'
+    assert_response :success
+  end
+  
+  def test_should_allow_delete_with_xml
+    delete :index, :format => 'xml'
+    assert_response :success
+  end
+end
+
+# no token is given, assume the cookie store is used
+class CsrfCookieMonsterController < ActionController::Base
+  verify_token :only => :index
+
+  def index
+    render :inline => "<%= form_tag('/') {} %>"
+  end
+  
+  def unsafe
+    render :text => 'pwn'
+  end
+  
+  def rescue_action(e) raise e end
+end
+
+class FakeSessionDbMan
+  def self.generate_digest(data)
+    Digest::SHA1.hexdigest("secure")
+  end
+end
+
+class CsrfCookieMonsterControllerTest < Test::Unit::TestCase
+  def setup
+    @controller = CsrfCookieMonsterController.new
+    @request    = ActionController::TestRequest.new
+    @response   = ActionController::TestResponse.new
+    # simulate a cookie session store
+    @request.session.instance_variable_set(:@dbman, FakeSessionDbMan)
+    class << @request.session
+      attr_reader :dbman
+    end
+    @token = Digest::SHA1.hexdigest("secure")
+    ActionController::Base.request_forgery_protection_token = :_token
+  end
+  
+  def teardown
+    ActionController::Base.request_forgery_protection_token = nil
+  end
+
+  def test_should_render_form_with_token_tag
+    get :index
+    assert_select 'form>div>input[name=?][value=?]', '_token', @token
+  end
+
+  # Replace this with your real tests.
+  def test_should_allow_get
+    get :index
+    assert_response :success
+  end
+  
+  def test_should_allow_post_without_token_on_unsafe_action
+    post :unsafe
+    assert_response :success
+  end
+  
+  def test_should_not_allow_post_without_token
+    assert_raises(ActionController::InvalidToken) { post :index }
+  end
+  
+  def test_should_not_allow_put_without_token
+    assert_raises(ActionController::InvalidToken) { put :index }
+  end
+  
+  def test_should_not_allow_delete_without_token
+    assert_raises(ActionController::InvalidToken) { delete :index }
+  end
+  
+  def test_should_not_allow_xhr_post_without_token
+    assert_raises(ActionController::InvalidToken) { xhr :post, :index }
+  end
+  
+  def test_should_not_allow_xhr_put_without_token
+    assert_raises(ActionController::InvalidToken) { xhr :put, :index }
+  end
+  
+  def test_should_not_allow_xhr_delete_without_token
+    assert_raises(ActionController::InvalidToken) { xhr :delete, :index }
+  end
+  
+  def test_should_allow_post_with_token
+    post :index, :_token => @token
+    assert_response :success
+  end
+  
+  def test_should_allow_put_with_token
+    put :index, :_token => @token
+    assert_response :success
+  end
+  
+  def test_should_allow_delete_with_token
+    delete :index, :_token => @token
+    assert_response :success
+  end
+  
+  def test_should_allow_post_with_xml
+    post :index, :format => 'xml'
+    assert_response :success
+  end
+  
+  def test_should_allow_put_with_xml
+    put :index, :format => 'xml'
+    assert_response :success
+  end
+  
+  def test_should_allow_delete_with_xml
+    delete :index, :format => 'xml'
+    assert_response :success
+  end
+end
+

actionpack/test/template/form_helper_test.rb

@@ -711,4 +711,8 @@ class FormHelperTest < Test::Unit::TestCase
     def post_path(post)
       "/posts/#{post.id}"
     end
+    
+    def request_forgery_protection_token
+      nil
+    end
 end

actionpack/test/template/form_tag_helper_test.rb

@@ -177,4 +177,9 @@ class FormTagHelperTest < Test::Unit::TestCase
     expected = %(<fieldset>Hello world!</fieldset>)
     assert_dom_equal expected, _erbout
   end
+  
+  def request_forgery_protection_token
+    nil
+    
+  end
 end

actionpack/test/template/prototype_helper_test.rb

@@ -60,6 +60,11 @@ module BaseTest
   end
 
 protected
+  
+  def request_forgery_protection_token
+    nil
+  end
+  
   def create_generator
     block = Proc.new { |*args| yield *args if block_given? } 
     JavaScriptGenerator.new self, &block

actionpack/test/template/scriptaculous_helper_test.rb

@@ -89,4 +89,8 @@ class ScriptaculousHelperTest < Test::Unit::TestCase
     assert_dom_equal %(<script type=\"text/javascript\">\n//<![CDATA[\nDroppables.add(\"droptarget1\", {accept:['tshirts','mugs'], onDrop:function(element){new Ajax.Updater('infobox', 'http://www.example.com/', {asynchronous:true, evalScripts:true, parameters:'id=' + encodeURIComponent(element.id)})}})\n//]]>\n</script>),
       drop_receiving_element("droptarget1", :accept => ['tshirts','mugs'], :update => 'infobox')
   end
+  
+  def request_forgery_protection_token
+    nil
+  end
 end

actionpack/test/template/url_helper_test.rb

@@ -267,6 +267,10 @@ class UrlHelperTest < Test::Unit::TestCase
     assert_dom_equal "<a href=\"&#109;&#97;&#105;&#108;&#116;&#111;&#58;%6d%65@%64%6f%6d%61%69%6e.%63%6f%6d\">&#109;&#101;&#40;&#97;&#116;&#41;&#100;&#111;&#109;&#97;&#105;&#110;&#40;&#100;&#111;&#116;&#41;&#99;&#111;&#109;</a>", mail_to("me@domain.com", nil, :encode => "hex", :replace_at => "(at)", :replace_dot => "(dot)")
     assert_dom_equal "<script type=\"text/javascript\">eval(unescape('%64%6f%63%75%6d%65%6e%74%2e%77%72%69%74%65%28%27%3c%61%20%68%72%65%66%3d%22%6d%61%69%6c%74%6f%3a%6d%65%40%64%6f%6d%61%69%6e%2e%63%6f%6d%22%3e%4d%79%20%65%6d%61%69%6c%3c%2f%61%3e%27%29%3b'))</script>", mail_to("me@domain.com", "My email", :encode => "javascript", :replace_at => "(at)", :replace_dot => "(dot)")
   end
+  
+  def request_forgery_protection_token
+    nil
+  end
 end
 
 class UrlHelperWithControllerTest < Test::Unit::TestCase