added XPermittedCrossDomainPolicies header support

README.md

@@ -6,6 +6,7 @@ The gem will automatically apply several headers that are related to security.
 - X-Frame-Options (XFO) - Prevents your content from being framed and potentially clickjacked. [X-Frame-Options draft](https://tools.ietf.org/html/draft-ietf-websec-x-frame-options-02)
 - X-XSS-Protection - [Cross site scripting heuristic filter for IE/Chrome](http://msdn.microsoft.com/en-us/library/dd565647\(v=vs.85\).aspx)
 - X-Content-Type-Options - [Prevent content type sniffing](http://msdn.microsoft.com/en-us/library/ie/gg622941\(v=vs.85\).aspx)
+- X-Permitted-Cross-Domain-Policies - [Restrict Adobe Flash Player's access to data](https://www.adobe.com/devnet/adobe-media-server/articles/cross-domain-xml-for-streaming.html)
 
 This gem has integration with Rails, but works for any Ruby code. See the sinatra example section.
 
@@ -48,6 +49,7 @@ The following methods are going to be called, unless they are provided in a `ski
 * `:set_x_frame_options_header`
 * `:set_x_xss_protection_header`
 * `:set_x_content_type_options_header`
+* `:set_x_permitted_cross_domain_policies_header`
 
 ### Bonus Features
 
@@ -65,6 +67,7 @@ This gem makes a few assumptions about how you will use some features.  For exam
   config.x_frame_options = 'DENY'
   config.x_content_type_options = "nosniff"
   config.x_xss_protection = {:value => 1, :mode => 'block'}
+  config.x_permitted_cross_domain_policies = 'none'
   config.csp = {
     :default_src => "https: self",
     :frame_src => "https: http:.twimg.com http://itunes.apple.com",
@@ -106,6 +109,7 @@ This configuration will likely work for most applications without modification.
 :x_frame_options  => {:value => 'SAMEORIGIN'}
 :x_xss_protection => {:value => 1, :mode => 'block'}  # set the :mode option to false to use "warning only" mode
 :x_content_type_options => {:value => 'nosniff'}
+:x_permitted_cross_domain_policies => {:value => 'none'}
 ```
 
 ### Content Security Policy (CSP)
@@ -335,6 +339,7 @@ require 'secure_headers'
   config.x_frame_options = 'DENY'
   config.x_content_type_options = "nosniff"
   config.x_xss_protection = {:value => 1, :mode => false}
+  config.x_permitted_cross_domain_policies = 'none'
   config.csp = {
     :default_src => "https: inline eval",
     :report_uri => '//example.com/uri-directive',
@@ -390,6 +395,7 @@ def before_load
     config.x_frame_options        = 'DENY'
     config.x_content_type_options = "nosniff"
     config.x_xss_protection       = {:value   => '1', :mode => false}
+    config.x_permitted_cross_domain_policies = 'none'
     config.csp                    = {
       :default_src => "https: inline eval",
       :report_uri => '//example.com/uri-directive',

fixtures/rails_3_2_12/config/initializers/secure_headers.rb

@@ -3,6 +3,7 @@
   config.x_frame_options = 'SAMEORIGIN'
   config.x_content_type_options = "nosniff"
   config.x_xss_protection = {:value => 1, :mode => 'block'}
+  config.x_permitted_cross_domain_policies = 'none'
   csp = {
     :default_src => "self",
     :script_src => "self nonce",

fixtures/rails_3_2_12/spec/controllers/other_things_controller_spec.rb

@@ -67,6 +67,11 @@ describe OtherThingsController, :type => :controller do
       expect(@env['X-Content-Type-Options']).to eq("nosniff")
     end
 
+    it "sets the X-Permitted-Cross-Domain-Policies" do
+      get '/'
+      expect(@env['X-Permitted-Cross-Domain-Policies']).to eq("none")
+    end
+
     context "using IE" do
       it "sets the X-Content-Type-Options header" do
         @env['HTTP_USER_AGENT'] = "Mozilla/5.0 (compatible; MSIE 10.6; Windows NT 6.1; Trident/5.0; InfoPath.2; SLCC1; .NET CLR 3.0.4506.2152; .NET CLR 3.5.30729; .NET CLR 2.0.50727) 3gpp-gba UNTRUSTED/1.0"

fixtures/rails_3_2_12/spec/controllers/things_controller_spec.rb

@@ -38,6 +38,11 @@ describe ThingsController, :type => :controller do
       expect(response.headers['X-Content-Type-Options']).to eq("nosniff")
     end
 
+    it "sets the X-Permitted-Cross-Domain-Policies" do
+      get :index
+      expect(response.headers['X-Permitted-Cross-Domain-Policies']).to eq("none")
+    end
+
     context "using IE" do
       it "sets the X-Content-Type-Options header" do
         request.env['HTTP_USER_AGENT'] = "Mozilla/5.0 (compatible; MSIE 10.6; Windows NT 6.1; Trident/5.0; InfoPath.2; SLCC1; .NET CLR 3.0.4506.2152; .NET CLR 3.5.30729; .NET CLR 2.0.50727) 3gpp-gba UNTRUSTED/1.0"

fixtures/rails_3_2_12_no_init/spec/controllers/other_things_controller_spec.rb

@@ -34,6 +34,11 @@ describe OtherThingsController, :type => :controller do
       expect(response.headers['X-Content-Type-Options']).to eq(SecureHeaders::XContentTypeOptions::Constants::DEFAULT_VALUE)
     end
 
+    it "sets the X-Permitted-Cross-Domain-Policies" do
+      get :index
+      expect(response.headers['X-Permitted-Cross-Domain-Policies']).to eq("none")
+    end
+
     context "using IE" do
       it "sets the X-Content-Type-Options header" do
         request.env['HTTP_USER_AGENT'] = "Mozilla/5.0 (compatible; MSIE 10.6; Windows NT 6.1; Trident/5.0; InfoPath.2; SLCC1; .NET CLR 3.0.4506.2152; .NET CLR 3.5.30729; .NET CLR 2.0.50727) 3gpp-gba UNTRUSTED/1.0"

fixtures/rails_3_2_12_no_init/spec/controllers/things_controller_spec.rb

@@ -38,6 +38,11 @@ describe ThingsController, :type => :controller do
       expect(response.headers['X-Content-Type-Options']).to eq(SecureHeaders::XContentTypeOptions::Constants::DEFAULT_VALUE)
     end
 
+    it "sets the X-Permitted-Cross-Domain-Policies" do
+      get :index
+      expect(response.headers['X-Permitted-Cross-Domain-Policies']).to eq("none")
+    end
+
     context "using IE" do
       it "sets the X-Content-Type-Options header" do
         request.env['HTTP_USER_AGENT'] = "Mozilla/5.0 (compatible; MSIE 10.6; Windows NT 6.1; Trident/5.0; InfoPath.2; SLCC1; .NET CLR 3.0.4506.2152; .NET CLR 3.5.30729; .NET CLR 2.0.50727) 3gpp-gba UNTRUSTED/1.0"

lib/secure_headers.rb

@@ -5,7 +5,8 @@ module SecureHeaders
   module Configuration
     class << self
       attr_accessor :hsts, :x_frame_options, :x_content_type_options,
-        :x_xss_protection, :csp, :x_download_options, :script_hashes
+        :x_xss_protection, :csp, :x_download_options, :script_hashes,
+        :x_permitted_cross_domain_policies
 
       def configure &block
         instance_eval &block
@@ -46,6 +47,7 @@ module SecureHeaders
       before_filter :set_x_xss_protection_header
       before_filter :set_x_content_type_options_header
       before_filter :set_x_download_options_header
+      before_filter :set_x_permitted_cross_domain_policies_header
     end
 
     # we can't use ||= because I'm overloading false => disable, nil => default
@@ -63,6 +65,7 @@ module SecureHeaders
       set_x_xss_protection_header(options[:x_xss_protection])
       set_x_content_type_options_header(options[:x_content_type_options])
       set_x_download_options_header(options[:x_download_options])
+      set_x_permitted_cross_domain_policies_header(options[:x_permitted_cross_domain_policies])
     end
 
     # set_csp_header - uses the request accessor and SecureHeader::Configuration settings
@@ -137,6 +140,10 @@ module SecureHeaders
       set_a_header(:x_download_options, XDownloadOptions, options)
     end
 
+    def set_x_permitted_cross_domain_policies_header(options=self.class.secure_headers_options[:x_permitted_cross_domain_policies])
+      set_a_header(:x_permitted_cross_domain_policies, XPermittedCrossDomainPolicies, options)
+    end
+
     private
 
     def set_a_header(name, klass, options=nil)
@@ -167,6 +174,7 @@ require "secure_headers/headers/strict_transport_security"
 require "secure_headers/headers/x_xss_protection"
 require "secure_headers/headers/x_content_type_options"
 require "secure_headers/headers/x_download_options"
+require "secure_headers/headers/x_permitted_cross_domain_policies"
 require "secure_headers/railtie"
 require "secure_headers/hash_helper"
 require "secure_headers/view_helper"

lib/secure_headers/headers/x_permitted_cross_domain_policies.rb

@@ -0,0 +1,40 @@
+module SecureHeaders
+  class XPCDPBuildError < StandardError; end
+  class XPermittedCrossDomainPolicies < Header
+    module Constants
+      XPCDP_HEADER_NAME = "X-Permitted-Cross-Domain-Policies"
+      DEFAULT_VALUE = 'none'
+      VALID_POLICIES = %w(all none master-only by-content-type by-ftp-filename)
+    end
+    include Constants
+
+    def initialize(config = nil)
+      @config = config
+      validate_config unless @config.nil?
+    end
+
+    def name
+      XPCDP_HEADER_NAME
+    end
+
+    def value
+      case @config
+      when NilClass
+        DEFAULT_VALUE
+      when String
+        @config
+      else
+        @config[:value]
+      end
+    end
+
+    private
+
+    def validate_config
+      value = @config.is_a?(Hash) ? @config[:value] : @config
+      unless VALID_POLICIES.include?(value.downcase)
+        raise XPCDPBuildError.new("Value can only be one of #{VALID_POLICIES.join(', ')}")
+      end
+    end
+  end
+end

spec/lib/secure_headers/headers/x_permitted_cross_domain_policies_spec.rb

@@ -0,0 +1,64 @@
+module SecureHeaders
+  describe XPermittedCrossDomainPolicies do
+    specify { expect(XPermittedCrossDomainPolicies.new.name).to eq(XPermittedCrossDomainPolicies::Constants::XPCDP_HEADER_NAME)}
+    specify { expect(XPermittedCrossDomainPolicies.new.value).to eq("none")}
+    specify { expect(XPermittedCrossDomainPolicies.new('master-only').value).to eq('master-only')}
+    specify { expect(XPermittedCrossDomainPolicies.new(:value => 'master-only').value).to eq('master-only') }
+
+    context "valid configuration values" do
+      it "accepts 'all'" do
+        expect {
+          XPermittedCrossDomainPolicies.new("all")
+        }.not_to raise_error
+
+        expect {
+          XPermittedCrossDomainPolicies.new(:value => "all")
+        }.not_to raise_error
+      end
+
+      it "accepts 'by-ftp-filename'" do
+        expect {
+          XPermittedCrossDomainPolicies.new("by-ftp-filename")
+        }.not_to raise_error
+
+        expect {
+          XPermittedCrossDomainPolicies.new(:value => "by-ftp-filename")
+        }.not_to raise_error
+      end
+
+      it "accepts 'by-content-type'" do
+        expect {
+          XPermittedCrossDomainPolicies.new("by-content-type")
+        }.not_to raise_error
+
+        expect {
+          XPermittedCrossDomainPolicies.new(:value => "by-content-type")
+        }.not_to raise_error
+      end
+      it "accepts 'master-only'" do
+        expect {
+          XPermittedCrossDomainPolicies.new("master-only")
+        }.not_to raise_error
+
+        expect {
+          XPermittedCrossDomainPolicies.new(:value => "master-only")
+        }.not_to raise_error
+      end
+
+      it "accepts nil" do
+        expect {
+          XPermittedCrossDomainPolicies.new
+        }.not_to raise_error
+      end
+    end
+
+    context 'invlaid configuration values' do
+
+      it "doesn't accept invalid values" do
+        expect {
+          XPermittedCrossDomainPolicies.new("open")
+        }.to raise_error
+      end
+    end
+  end
+end

spec/lib/secure_headers_spec.rb

@@ -18,7 +18,7 @@ describe SecureHeaders do
     allow(subject).to receive(:request).and_return(request)
   end
 
-  ALL_HEADERS = Hash[[:hsts, :csp, :x_frame_options, :x_content_type_options, :x_xss_protection].map{|header| [header, false]}]
+  ALL_HEADERS = Hash[[:hsts, :csp, :x_frame_options, :x_content_type_options, :x_xss_protection, :x_permitted_cross_domain_policies].map{|header| [header, false]}]
 
   def stub_user_agent val
     allow(request).to receive_message_chain(:env, :[]).and_return(val)
@@ -36,6 +36,7 @@ describe SecureHeaders do
       config.x_xss_protection = nil
       config.csp = nil
       config.x_download_options = nil
+      config.x_permitted_cross_domain_policies = nil
     end
   end
 
@@ -46,6 +47,7 @@ describe SecureHeaders do
     subject.set_x_content_type_options_header
     subject.set_x_xss_protection_header
     subject.set_x_download_options_header
+    subject.set_x_permitted_cross_domain_policies_header
   end
 
   describe "#set_header" do
@@ -64,7 +66,7 @@ describe SecureHeaders do
     USER_AGENTS.each do |name, useragent|
       it "sets all default headers for #{name} (smoke test)" do
         stub_user_agent(useragent)
-        number_of_headers = 6
+        number_of_headers = 7
         expect(subject).to receive(:set_header).exactly(number_of_headers).times # a request for a given header
         subject.set_csp_header
         subject.set_x_frame_options_header
@@ -72,6 +74,7 @@ describe SecureHeaders do
         subject.set_x_xss_protection_header
         subject.set_x_content_type_options_header
         subject.set_x_download_options_header
+        subject.set_x_permitted_cross_domain_policies_header
       end
     end
 
@@ -96,6 +99,11 @@ describe SecureHeaders do
       subject.set_x_frame_options_header(false)
     end
 
+    it "does not set the X-Permitted-Cross-Domain-Policies header if disabled" do
+      should_not_assign_header(XPCDP_HEADER_NAME)
+      subject.set_x_permitted_cross_domain_policies_header(false)
+    end
+
     it "does not set the HSTS header if disabled" do
       should_not_assign_header(HSTS_HEADER_NAME)
       subject.set_hsts_header(false)
@@ -133,6 +141,7 @@ describe SecureHeaders do
           config.x_xss_protection = false
           config.csp = false
           config.x_download_options = false
+          config.x_permitted_cross_domain_policies = false
         end
         expect(subject).not_to receive(:set_header)
         set_security_headers(subject)
@@ -249,4 +258,16 @@ describe SecureHeaders do
       end
     end
   end
+
+  describe "#set_x_permitted_cross_domain_policies_header" do
+    it "sets the X-Permitted-Cross-Domain-Policies header" do
+      should_assign_header(XPCDP_HEADER_NAME, SecureHeaders::XPermittedCrossDomainPolicies::Constants::DEFAULT_VALUE)
+      subject.set_x_permitted_cross_domain_policies_header
+    end
+
+    it "allows a custom X-Permitted-Cross-Domain-Policies header" do
+      should_assign_header(XPCDP_HEADER_NAME, "master-only")
+      subject.set_x_permitted_cross_domain_policies_header(:value => 'master-only')
+    end
+  end
 end

spec/spec_helper.rb

@@ -13,6 +13,7 @@ include ::SecureHeaders::XFrameOptions::Constants
 include ::SecureHeaders::XXssProtection::Constants
 include ::SecureHeaders::XContentTypeOptions::Constants
 include ::SecureHeaders::XDownloadOptions::Constants
+include ::SecureHeaders::XPermittedCrossDomainPolicies::Constants
 
 USER_AGENTS = {
   :firefox => 'Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:14.0) Gecko/20100101 Firefox/14.0.1',