auth plugin

auth

require 'base64'

class Zoidberg::Plugin::Auth
  Zoidberg::Plugin.define :auth, self

  def initialize(app)
    app.generic_controller.send(:include, InstanceMethods)
  end

  module InstanceMethods

    def basic(realm = 'realm', &blk)
      Basic.new(self, realm).authenticate(&blk)
    end
  end

  private

  class Scheme

    def initialize(c, realm)
      @c = c
      @realm = realm
    end

    def authorization
      @c.req.headers.authorization && @c.req.headers.authorization.split(/ /, 2)
    end

    def name
      authorization.first
    end

    def params
      authorization.last
    end

    def bad_request
      @c.res.status = 400
      @c.res.body.close
      @c.serve
      throw :halt
    end

    def unauthorized
      @c.res.status = 401
      @c.res.headers.www_authenticate = challenge % @realm
      @c.res.body.close
      @c.serve
      throw :halt
    end
  end

  class Basic < Scheme

    def authenticate(&blk)
      return unauthorized unless authorization

      return bad_request unless valid?

      result = blk.call(username, password)
      return result if result

      unauthorized
    end

    def challenge
      'Basic realm="%s"'
    end

    def params
      Base64.decode64(super).split(/:/, 2)
    end

    def username
      params.first
    end

    def password
      params.last
    end

    def valid?
      name =~ /^basic$/i
    end
  end
end