Makes it dead easy to do HTTP Token authentication.

Simple Token example:

  class PostsController < ApplicationController
    TOKEN = "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_token do |token, options|
          token == TOKEN
        end
      end
  end

Here is a more advanced Token example where only Atom feeds and the XML API is protected by HTTP token authentication, the regular HTML interface is protected by a session approach:

  class ApplicationController < ActionController::Base
    before_filter :set_account, :authenticate

    protected
      def set_account
        @account = Account.find_by_url_name(request.subdomains.first)
      end

      def authenticate
        case request.format
        when Mime::XML, Mime::ATOM
          if user = authenticate_with_http_token { |t, o| @account.users.authenticate(t, o) }
            @current_user = user
          else
            request_http_token_authentication
          end
        else
          if session_authenticated?
            @current_user = @account.users.find(session[:authenticated][:user_id])
          else
            redirect_to(login_url) and return false
          end
        end
      end
  end

In your integration tests, you can do something like this:

  def test_access_granted_from_xml
    get(
      "/notes/1.xml", nil,
      :authorization => ActionController::HttpAuthentication::Token.encode_credentials(users(:dhh).token)
    )

    assert_equal 200, status
  end

On shared hosts, Apache sometimes doesn’t pass authentication headers to FCGI instances. If your environment matches this description and you cannot authenticate, try this rule in your Apache setup:

  RewriteRule ^(.*)$ dispatch.fcgi [E=X-HTTP_AUTHORIZATION:%{HTTP:Authorization},QSA,L]
Methods
A
E
T
Classes and Modules
Instance Public methods
authenticate(controller, &login_procedure)

If token Authorization header is present, call the login procedure with the present token and options.

controller - ActionController::Base instance for the current request. login_procedure - Proc to call if a token is present. The Proc should

                  take 2 arguments:
                    authenticate(controller) { |token, options| ... }

Returns the return value of `&login_procedure` if a token is found. Returns nil if no token is found.

     # File actionpack/lib/action_controller/metal/http_authentication.rb, line 412
412:       def authenticate(controller, &login_procedure)
413:         token, options = token_and_options(controller.request)
414:         unless token.blank?
415:           login_procedure.call(token, options)
416:         end
417:       end
authentication_request(controller, realm)

Sets a WWW-Authenticate to let the client know a token is desired.

controller - ActionController::Base instance for the outgoing response. realm - String realm to use in the header.

Returns nothing.

     # File actionpack/lib/action_controller/metal/http_authentication.rb, line 460
460:       def authentication_request(controller, realm)
461:         controller.headers["WWW-Authenticate"] = %(Token realm="#{realm.gsub(/"/, "")}")
462:         controller.__send__ :render, :text => "HTTP Token: Access denied.\n", :status => :unauthorized
463:       end
encode_credentials(token, options = {})

Encodes the given token and options into an Authorization header value.

token - String token. options - optional Hash of the options.

Returns String.

     # File actionpack/lib/action_controller/metal/http_authentication.rb, line 447
447:       def encode_credentials(token, options = {})
448:         values = ["token=#{token.to_s.inspect}"] + options.map do |key, value|
449:           "#{key}=#{value.to_s.inspect}"
450:         end
451:         "Token #{values * ", "}"
452:       end
token_and_options(request)

Parses the token and options out of the token authorization header. If the header looks like this:

  Authorization: Token token="abc", nonce="def"

Then the returned token is “abc”, and the options is {:nonce => “def”}

request - ActionDispatch::Request instance with the current headers.

Returns an Array of [String, Hash] if a token is present. Returns nil if no token is found.

     # File actionpack/lib/action_controller/metal/http_authentication.rb, line 428
428:       def token_and_options(request)
429:         if request.authorization.to_s[/^Token (.*)/]
430:           values = Hash[$1.split(',').map do |value|
431:             value.strip!                      # remove any spaces between commas and values
432:             key, value = value.split(/\=\"?/) # split key=value pairs
433:             value.chomp!('"')                 # chomp trailing " in value
434:             value.gsub!(/\\\"/, '"')          # unescape remaining quotes
435:             [key, value]
436:           end]
437:           [values.delete("token"), values.with_indifferent_access]
438:         end
439:       end