ImageFactory OAuth request support

Adds in the ability to use 2 Legged OAuth for securing
requests to imagefactory.

README.rdoc

@@ -14,6 +14,21 @@ Tim wraps all this up in a clean, simply RESTful API.
 You can read the full presentation
 here[http://www.aeolusproject.org/docs/presentations/2012-nov-conference/tim.odp].
 
+== Configuration
+
+=== Securing Image Factory requests
+
+It is possible to secure Image Factory requests using 2 Legged OAuth.  To use 2
+Legged OAuth you must set the OAuth consumer key, consumer secret and url in the
+Tim::ImageFactory::Base.config.
+
+Example:
+
+  oauth_config = {:consumer_key => "mock-key",
+                  :consumer_secret => "mock-secret",
+                  :site => "http://localhost:8075/imagefactory/"}
+  Tim::ImageFactory::Base.config = oauth_config
+
 == Running Tests
 
 {<img src="https://secure.travis-ci.org/aeolus-incubator/tim.png"

lib/image_factory/image_factory.rb

@@ -1,4 +1,5 @@
 require "active_resource"
+require File.join(File.dirname(__FILE__), 'oauth', 'active_resource_oauth_client')
 require File.join(File.dirname(__FILE__), 'model', 'base')
 require File.join(File.dirname(__FILE__), 'model', 'target_image')
-require File.join(File.dirname(__FILE__), 'model', 'provider_image')
+require File.join(File.dirname(__FILE__), 'model', 'provider_image')

lib/image_factory/oauth/active_resource_oauth_client.rb

@@ -0,0 +1,52 @@
+require 'oauth'
+
+# Monkey-patch ActiveResource to allow us to merge our OAuth headers in.
+# Portions of the below are taken from Active Resource which is MIT licensed;
+# hence this whole file is being licensed under the MIT License to err on the side of safety.
+module ActiveResourceOAuthClient
+  ActiveResource::Connection.class_eval do
+    def request_with_oauth(method, path, *arguments)
+      @oauth_config = Tim::ImageFactory::Base.config || {}
+      # Take care to fall back to the standard request method if we don't have full OAuth credentials
+      unless use_oauth_for_url?("#{site.scheme}://#{site.host}:#{site.port}#{path}")
+        return request_without_oauth(method, path, *arguments)
+      end
+      result = ActiveSupport::Notifications.instrument("request.active_resource") do |payload|
+        payload[:method] = method
+        payload[:request_uri] = "#{site.scheme}://#{site.host}:#{site.port}#{path}"
+        puts "#{payload[:method]} #{payload[:request_uri]}"
+        oauth_consumer = OAuth::Consumer.new(
+          @oauth_config[:consumer_key],
+          @oauth_config[:consumer_secret],
+          :site => @oauth_config[:site] )
+        puts @oauth_config[:consumer_key] + " " + @oauth_config[:consumer_secret]
+        token = OAuth::AccessToken.new(oauth_consumer)
+        base_request = oauth_consumer.create_signed_request(method, path, token, {}, *arguments)
+        payload[:result] = http.request(base_request)
+      end
+      # Error-handling code from OAuth
+      # http://wiki.oauth.net/w/page/12238543/ProblemReporting
+      auth_header = result.to_hash['www-authenticate']
+      problem_header = auth_header ? auth_header.select{|h| h =~ /^OAuth /}.select{|h| h =~ /oauth_problem/}.first : nil
+      if auth_header && problem_header
+        params = OAuth::Helper.parse_header(problem_header)
+        raise OAuth::Problem.new(params.delete("oauth_problem"), result, params)
+      end
+      # Error-handling code from ActiveResource
+      handle_response(result)
+      rescue Timeout::Error => e
+        raise TimeoutError.new(e.message)
+      rescue OpenSSL::SSL::SSLError => e
+        raise SSLError.new(e.message)
+    end
+
+    # Currently, only Factory calls should use OAuth -- extend as needed
+    def use_oauth_for_url?(url)
+      Tim::ImageFactory::Base.use_oauth? and
+        url.include?(Tim::ImageFactory::Base.config[:site])
+    end
+
+    alias_method_chain :request, :oauth
+
+  end
+end

test/dummy/config/initializers/tim.rb

@@ -1,8 +1,16 @@
 Tim.user_class = "User"
 Tim.provider_account_class = "ProviderAccount"
 Tim.provider_type_class = "ProviderType"
+
 # Image Factory URL
 Tim::ImageFactory::Base.site = "http://localhost:8075/imagefactory"
+
+# Example OAuth Configuration
+#oauth_config = {:consumer_key => "mock-key",
+#                :consumer_secret => "mock-secret",
+#                :site => "http://localhost:8075/imagefactory/"}#
+#Tim::ImageFactory::Base.config = oauth_config
+
 # FIXME: We should be able to infer these from Routes
 Tim::ImageFactory::TargetImage.callback_url = "http://localhost:3000/tim/target_images/"
 Tim::ImageFactory::ProviderImage.callback_url = "http://localhost:3000/tim/provider_images/"

tim.gemspec

@@ -21,6 +21,7 @@ Gem::Specification.new do |s|
   s.add_dependency "rails", "~> 3.2"
   s.add_dependency "haml"
   s.add_dependency "nokogiri"
+  s.add_dependency "oauth"
 
   s.add_development_dependency "sqlite3"
   s.add_development_dependency "rspec-rails"