Module ActionController::HttpAuthentication::Basic

Makes it dead easy to do HTTP Basic and Digest authentication.

Simple Basic example

  class PostsController < ApplicationController
    http_basic_authenticate_with :name => "dhh", :password => "secret", :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
 end

Advanced Basic example

Here is a more advanced Basic example where only Atom feeds and the XML API is protected by HTTP 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_basic { |u, p| @account.users.authenticate(u, p) }
            @current_user = user
          else
            request_http_basic_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,
      'HTTP_AUTHORIZATION' => ActionController::HttpAuthentication::Basic.encode_credentials(users(:dhh).name, users(:dhh).password)
    )

    assert_equal 200, status
  end

Simple Digest example

  require 'digest/md5'
  class PostsController < ApplicationController
    REALM = "SuperSecret"
    USERS = {"dhh" => "secret", #plain text password
             "dap" => Digest::MD5.hexdigest(["dap",REALM,"secret"].join(":"))}  #ha1 digest password

    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 |username|
          USERS[username]
        end
      end
  end

Notes

The authenticate_or_request_with_http_digest block must return the user’s password or the ha1 digest hash so the framework can appropriately hash to check the user’s credentials. Returning nil will cause authentication to fail.

Storing the ha1 hash: MD5(username:realm:password), is better than storing a plain password. If the password file or database is compromised, the attacker would be able to use the ha1 hash to authenticate as the user at this realm, but would not have the user’s password to try using at other sites.

In rare instances, web servers or front proxies strip authorization headers before they reach your application. You can debug this situation by logging all environment variables, and check for HTTP_AUTHORIZATION, amongst others.