HTTP Digest authentication [#1230 state:resolved]

actionpack/lib/action_controller/http_authentication.rb

@@ -55,7 +55,31 @@ module HttpAuthentication
     #       end
     #   end
     # 
-    # 
+    # Simple Digest example. Note the block must return the user's password so the framework 
+    # can appropriately hash it to check the user's credentials. Returning nil will cause authentication to fail. 
+    #  
+    #   class PostsController < ApplicationController 
+    #     Users = {"dhh" => "secret"} 
+    #    
+    #     before_filter :authenticate, :except => [ :index ] 
+    #    
+    #     def index 
+    #       render :text => "Everyone can see me!" 
+    #     end 
+    #    
+    #     def edit 
+    #       render :text => "I'm only accessible if you know the password" 
+    #     end 
+    #    
+    #     private 
+    #       def authenticate 
+    #         authenticate_or_request_with_http_digest(realm) do |user_name|  
+    #           Users[user_name] 
+    #         end 
+    #       end 
+    #   end
+    #
+    #
     # In your integration tests, you can do something like this:
     # 
     #   def test_access_granted_from_xml
@@ -108,7 +132,10 @@ def authorization(request)
       end
 
       def decode_credentials(request)
-        ActiveSupport::Base64.decode64(authorization(request).split.last || '')
+        # Properly decode credentials spanning a new-line
+        auth = authorization(request)
+        auth.slice!('Basic ')
+        ActiveSupport::Base64.decode64(auth || '')
       end
 
       def encode_credentials(user_name, password)
@@ -120,5 +147,165 @@ def authentication_request(controller, realm)
         controller.__send__ :render, :text => "HTTP Basic: Access denied.\n", :status => :unauthorized
       end
     end
+
+    module Digest
+      extend self
+
+      module ControllerMethods
+        def authenticate_or_request_with_http_digest(realm = "Application", &password_procedure)
+          begin 
+            authenticate_with_http_digest!(realm, &password_procedure)
+          rescue ActionController::HttpAuthentication::Error => e
+            msg = e.message
+            msg = "#{msg} expected '#{e.expected}' was '#{e.was}'" unless e.expected.nil?
+            raise msg if e.fatal?
+            request_http_digest_authentication(realm, msg)
+          end
+        end
+
+        # Authenticate using HTTP Digest, throwing ActionController::HttpAuthentication::Error on failure.
+        # This allows more detailed analysis of authentication failures
+        # to be relayed to the client.
+        def authenticate_with_http_digest!(realm = "Application", &login_procedure)
+            HttpAuthentication::Digest.authenticate(self, realm, &login_procedure)
+        end
+
+        # Authenticate with HTTP Digest, returns true or false
+        def authenticate_with_http_digest(realm = "Application", &login_procedure)
+          HttpAuthentication::Digest.authenticate(self, realm, &login_procedure) rescue false
+        end
+
+        # Render output including the HTTP Digest authentication header
+        def request_http_digest_authentication(realm = "Application", message = nil)
+          HttpAuthentication::Digest.authentication_request(self, realm, message)
+        end
+
+        # Add HTTP Digest authentication header to result headers
+        def http_digest_authentication_header(realm = "Application")
+          HttpAuthentication::Digest.authentication_header(self, realm)
+        end
+      end
+
+      # Raises error unless authentictaion succeeds, returns true otherwise
+      def authenticate(controller, realm, &password_procedure)
+        raise Error.new(false), "No authorization header found" unless authorization(controller.request)
+        validate_digest_response(controller, realm, &password_procedure)
+        true
+      end
+
+      def authorization(request)
+        request.env['HTTP_AUTHORIZATION']   ||
+        request.env['X-HTTP_AUTHORIZATION'] ||
+        request.env['X_HTTP_AUTHORIZATION'] ||
+        request.env['REDIRECT_X_HTTP_AUTHORIZATION']
+      end
+
+      # Raises error unless the request credentials response value matches the expected value.
+      def validate_digest_response(controller, realm, &password_procedure) 
+        credentials = decode_credentials(controller.request) 
+
+        # Check the nonce, opaque and realm.
+        # Ignore nc, as we have no way to validate the number of times this nonce has been used
+        validate_nonce(controller.request, credentials[:nonce])
+        raise Error.new(false, realm, credentials[:realm]), "Realm doesn't match" unless realm == credentials[:realm]
+        raise Error.new(true, opaque(controller.request), credentials[:opaque]),"Opaque doesn't match" unless opaque(controller.request) == credentials[:opaque]
+
+        password = password_procedure.call(credentials[:username])
+        raise Error.new(false), "No password" if password.nil?
+        expected = expected_response(controller.request.env['REQUEST_METHOD'], controller.request.url, credentials, password)
+        raise Error.new(false, expected, credentials[:response]), "Invalid response" unless expected == credentials[:response]
+      end 
+
+      # Returns the expected response for a request of +http_method+ to +uri+ with the decoded +credentials+ and the expected +password+ 
+      def expected_response(http_method, uri, credentials, password) 
+        ha1 = ::Digest::MD5.hexdigest([credentials[:username], credentials[:realm], password].join(':')) 
+        ha2 = ::Digest::MD5.hexdigest([http_method.to_s.upcase,uri].join(':')) 
+        ::Digest::MD5.hexdigest([ha1,credentials[:nonce], credentials[:nc], credentials[:cnonce],credentials[:qop],ha2].join(':')) 
+      end  
+
+      def encode_credentials(http_method, credentials, password) 
+        credentials[:response] = expected_response(http_method, credentials[:uri], credentials, password) 
+        "Digest " + credentials.sort_by {|x| x[0].to_s }.inject([]) {|a, v| a << "#{v[0]}='#{v[1]}'" }.join(', ') 
+      end 
+
+      def decode_credentials(request) 
+        authorization(request).to_s.gsub(/^Digest\s+/,'').split(',').inject({}) do |hash, pair| 
+          key, value = pair.split('=', 2) 
+          hash[key.strip.to_sym] = value.to_s.gsub(/^"|"$/,'').gsub(/'/, '') 
+          hash 
+        end 
+      end 
+
+      def authentication_header(controller, realm)
+        controller.headers["WWW-Authenticate"] = %(Digest realm="#{realm}", qop="auth", algorithm=MD5, nonce="#{nonce(controller.request)}", opaque="#{opaque(controller.request)}") 
+      end
+
+      def authentication_request(controller, realm, message = "HTTP Digest: Access denied")
+        authentication_header(controller, realm)
+        controller.send! :render, :text => message, :status => :unauthorized
+      end
+
+      # Uses an MD5 digest based on time to generate a value to be used only once.
+      #
+      # A server-specified data string which should be uniquely generated each time a 401 response is made.
+      # It is recommended that this string be base64 or hexadecimal data.
+      # Specifically, since the string is passed in the header lines as a quoted string, the double-quote character is not allowed.
+      #
+      # The contents of the nonce are implementation dependent.
+      # The quality of the implementation depends on a good choice.
+      # A nonce might, for example, be constructed as the base 64 encoding of
+      #
+      # => time-stamp H(time-stamp ":" ETag ":" private-key)
+      #
+      # where time-stamp is a server-generated time or other non-repeating value,
+      # ETag is the value of the HTTP ETag header associated with the requested entity,
+      # and private-key is data known only to the server.
+      # With a nonce of this form a server would recalculate the hash portion after receiving the client authentication header and
+      # reject the request if it did not match the nonce from that header or
+      # if the time-stamp value is not recent enough. In this way the server can limit the time of the nonce's validity.
+      # The inclusion of the ETag prevents a replay request for an updated version of the resource.
+      # (Note: including the IP address of the client in the nonce would appear to offer the server the ability
+      # to limit the reuse of the nonce to the same client that originally got it.
+      # However, that would break proxy farms, where requests from a single user often go through different proxies in the farm.
+      # Also, IP address spoofing is not that hard.)
+      #
+      # An implementation might choose not to accept a previously used nonce or a previously used digest, in order to
+      # protect against a replay attack. Or, an implementation might choose to use one-time nonces or digests for
+      # POST or PUT requests and a time-stamp for GET requests. For more details on the issues involved see Section 4
+      # of this document.
+      #
+      # The nonce is opaque to the client.
+      def nonce(request, time = Time.now)
+        session_id = request.is_a?(String) ? request : request.session.session_id
+        t = time.to_i
+        hashed = [t, session_id]
+        digest = ::Digest::MD5.hexdigest(hashed.join(":"))
+        Base64.encode64("#{t}:#{digest}").gsub("\n", '')
+      end
+
+      def validate_nonce(request, value)
+        t = Base64.decode64(value).split(":").first.to_i
+        raise Error.new(true), "Stale Nonce" if (t - Time.now.to_i).abs > 10 * 60
+        n = nonce(request, t)
+        raise Error.new(true, value, n), "Bad Nonce" unless n == value
+      end
+
+      # Opaque based on digest of session_id
+      def opaque(request)
+        session_id = request.is_a?(String) ? request : request.session.session_id
+        @opaque ||= Base64.encode64(::Digest::MD5::hexdigest(session_id)).gsub("\n", '')
+      end
+    end
+
+    class Error < RuntimeError
+      attr_accessor :expected, :was
+      def initialize(fatal = false, expected = nil, was = nil)
+        @fatal = fatal
+        @expected = expected
+        @was = was
+      end
+
+      def fatal?; @fatal; end
+    end
   end
 end

actionpack/lib/action_controller/integration.rb

@@ -68,6 +68,15 @@ class Session
       # A running counter of the number of requests processed.
       attr_accessor :request_count
 
+      # Nonce value for Digest Authentication, implicitly set on response with WWW-Authentication
+      attr_accessor :nonce
+
+      # Opaque value for Digest Authentication, implicitly set on response with WWW-Authentication
+      attr_accessor :opaque
+
+      # Opaque value for Authentication, implicitly set on response with WWW-Authentication
+      attr_accessor :realm
+
       class MultiPartNeededException < Exception
       end
 
@@ -243,6 +252,53 @@ def xml_http_request(request_method, path, parameters = nil, headers = nil)
       end
       alias xhr :xml_http_request
 
+      def request_with_noauth(http_method, uri, parameters, headers) 
+        process_with_auth http_method, uri, parameters, headers
+      end 
+
+      # Performs a request with the given http_method and parameters, including HTTP Basic authorization headers. 
+      # See get() for more details on paramters and headers. 
+      # 
+      # You can perform GET, POST, PUT, DELETE, and HEAD requests with #get_with_basic, #post_with_basic, 
+      # #put_with_basic, #delete_with_basic, and #head_with_basic. 
+      def request_with_basic(http_method, uri, parameters, headers, user_name, password) 
+        process_with_auth http_method, uri, parameters, headers.merge(:authorization => ActionController::HttpAuthentication::Basic.encode_credentials(user_name, password)) 
+      end 
+
+      # Performs a request with the given http_method and parameters, including HTTP Digest authorization headers. 
+      # See get() for more details on paramters and headers. 
+      # 
+      # You can perform GET, POST, PUT, DELETE, and HEAD requests with #get_with_digest, #post_with_digest, 
+      # #put_with_digest, #delete_with_digest, and #head_with_digest. 
+      def request_with_digest(http_method, uri, parameters, headers, user_name, password) 
+        # Realm, Nonce, and Opaque taken from previoius 401 response
+
+        credentials = {
+          :username => user_name,
+          :realm    => @realm,
+          :nonce    => @nonce,
+          :qop      => "auth",
+          :nc       => "00000001",
+          :cnonce   => "0a4f113b",
+          :opaque   => @opaque,
+          :uri      => uri
+        }
+
+        raise "Digest request without previous 401 response" if @opaque.nil?
+
+        process_with_auth http_method, uri, parameters, headers.merge(:authorization => ActionController::HttpAuthentication::Digest.encode_credentials(http_method, credentials, password)) 
+      end 
+
+      # def get_with_basic, def post_with_basic, def put_with_basic, def delete_with_basic, def head_with_basic 
+      # def get_with_digest, def post_with_digest, def put_with_digest, def delete_with_digest, def head_with_digest 
+      [:get, :post, :put, :delete, :head].each do |method| 
+        [:noauth, :basic, :digest].each do |auth_type| 
+          define_method("#{method}_with_#{auth_type}") do |uri, parameters, headers, *auth| 
+            send("request_with_#{auth_type}", method, uri, parameters, headers, *auth) 
+          end 
+        end 
+      end
+
       # Returns the URL for the given options, according to the rules specified
       # in the application's routes.
       def url_for(options)
@@ -364,6 +420,32 @@ def process(method, path, parameters = nil, headers = nil)
           return status
         end
 
+        # Same as process, but handles authentication returns to perform
+        # Basic or Digest authentication
+        def process_with_auth(method, path, parameters = nil, headers = nil)
+          status = process(method, path, parameters, headers)
+
+          if status == 401
+            # Extract authentication information from response
+            auth_data = @response.headers['WWW-Authenticate']
+            if /^Basic /.match(auth_data)
+              # extract realm, to be used in subsequent request
+              @realm = auth_header.split(' ')[1]
+            elsif /^Digest/.match(auth_data)
+              creds = auth_data.to_s.gsub(/^Digest\s+/,'').split(',').inject({}) do |hash, pair| 
+                key, value = pair.split('=', 2) 
+                hash[key.strip.to_sym] = value.to_s.gsub(/^"|"$/,'').gsub(/'/, '') 
+                hash 
+              end 
+              @realm = creds[:realm]
+              @nonce = creds[:nonce]
+              @opaque = creds[:opaque]
+            end
+          end
+
+          return status
+        end
+
         # Encode the cookies hash in a format suitable for passing to a
         # request.
         def encode_cookies

actionpack/test/controller/http_digest_authentication_test.rb

@@ -0,0 +1,73 @@
+require 'abstract_unit'
+
+class HttpDigestAuthenticationTest < Test::Unit::TestCase
+  include ActionController::HttpAuthentication::Digest
+
+  class DummyController
+    attr_accessor :headers, :renders, :request, :response
+
+    def initialize
+      @headers, @renders = {}, []
+      @request = ActionController::TestRequest.new
+      @response = ActionController::TestResponse.new
+      request.session.session_id = "test_session"
+    end
+
+    def render(options)
+      self.renderers << options
+    end
+  end
+
+  def setup
+    @controller = DummyController.new
+    @credentials = {
+      :username => "dhh",
+      :realm    => "testrealm@host.com",
+      :nonce    => ActionController::HttpAuthentication::Digest.nonce(@controller.request),
+      :qop      => "auth",
+      :nc       => "00000001",
+      :cnonce   => "0a4f113b",
+      :opaque   => ActionController::HttpAuthentication::Digest.opaque(@controller.request),
+      :uri      => "http://test.host/"
+    }
+    @encoded_credentials = ActionController::HttpAuthentication::Digest.encode_credentials("GET", @credentials, "secret")
+  end
+
+  def test_decode_credentials
+    set_headers
+    assert_equal @credentials, decode_credentials(@controller.request) 
+  end 
+
+  def test_nonce_format
+    assert_nothing_thrown do
+      validate_nonce(@controller.request, nonce(@controller.request))
+    end
+  end
+
+  def test_authenticate_should_raise_for_nil_password
+    set_headers ActionController::HttpAuthentication::Digest.encode_credentials(:get, @credentials, nil)
+    assert_raise ActionController::HttpAuthentication::Error do
+      authenticate(@controller, @credentials[:realm]) { |user| user == "dhh" && "secret" }
+    end
+  end 
+
+  def test_authenticate_should_raise_for_incorrect_password 
+    set_headers
+    assert_raise ActionController::HttpAuthentication::Error do
+      authenticate(@controller, @credentials[:realm]) { |user| user == "dhh" && "bad password" }
+    end
+  end 
+
+  def test_authenticate_should_not_raise_for_correct_password 
+    set_headers
+    assert_nothing_thrown do
+      authenticate(@controller, @credentials[:realm]) { |user| user == "dhh" && "secret" }
+    end
+  end 
+
+  private
+    def set_headers(value = @encoded_credentials, name = 'HTTP_AUTHORIZATION', method = "GET")
+      @controller.request.env[name] = value
+      @controller.request.env["REQUEST_METHOD"] = method
+    end
+end