Added Digest Access Authentication support to HTTParty.

New File: lib/net_http_digest.rb
From: http://codesnippets.joyent.com/posts/show/1075
This extends Net::HTTP with a new digest_authentication method.

Extended HTTParty to use this new functionality in a backwards compatible
fashion.  To use the new digest_auth method, merely use :digest_auth as your
HTTParty credentials option instead of :basic_auth.  HTTParty will take care
of the rest.

lib/httparty.rb

@@ -11,6 +11,7 @@ dir = Pathname(__FILE__).dirname.expand_path
 
 require dir + 'httparty/module_inheritable_attributes'
 require dir + 'httparty/cookie_hash'
+require dir + 'net_digest_auth'
 
 module HTTParty
   VERSION = "0.5.2".freeze

lib/httparty/request.rb

@@ -94,12 +94,16 @@ module HTTParty
         options[:body].is_a?(Hash) ? options[:body].to_params : options[:body]
       end
 
+      def credentials
+        options[:basic_auth] || options[:digest_auth]
+      end
+
       def username
-        options[:basic_auth][:username]
+        credentials[:username]
       end
 
       def password
-        options[:basic_auth][:password]
+        credentials[:password]
       end
 
       def setup_raw_request
@@ -107,6 +111,14 @@ module HTTParty
         @raw_request.body = body if body
         @raw_request.initialize_http_header(options[:headers])
         @raw_request.basic_auth(username, password) if options[:basic_auth]
+        setup_digest_auth if options[:digest_auth]
+      end
+      
+      def setup_digest_auth
+        res = http.head(uri.request_uri)
+        if res['www-authenticate'] != nil && res['www-authenticate'].length > 0
+          @raw_request.digest_auth(username, password, res)
+        end
       end
 
       def perform_actual_request
@@ -182,7 +194,9 @@ module HTTParty
         raise HTTParty::RedirectionTooDeep.new(last_response), 'HTTP redirects too deep' if options[:limit].to_i <= 0
         raise ArgumentError, 'only get, post, put, delete, head, and options methods are supported' unless SupportedHTTPMethods.include?(http_method)
         raise ArgumentError, ':headers must be a hash' if options[:headers] && !options[:headers].is_a?(Hash)
+        raise ArgumentError, 'only one authentication method, :basic_auth or :digest_auth may be used at a time' if options[:basic_auth] && options[:digest_auth]
         raise ArgumentError, ':basic_auth must be a hash' if options[:basic_auth] && !options[:basic_auth].is_a?(Hash)
+        raise ArgumentError, ':digest_auth must be a hash' if options[:digest_auth] && !options[:digest_auth].is_a?(Hash)
         raise ArgumentError, ':query must be hash if using HTTP Post' if post? && !options[:query].nil? && !options[:query].is_a?(Hash)
       end
 

lib/net_digest_auth.rb

@@ -0,0 +1,44 @@
+require 'digest/md5'
+require 'net/http'
+
+module Net
+  module HTTPHeader
+    @@nonce_count = -1
+    CNONCE = Digest::MD5.new.update("%x" % (Time.now.to_i + rand(65535))).hexdigest
+    def digest_auth(user, password, response)
+      # based on http://segment7.net/projects/ruby/snippets/digest_auth.rb
+      @@nonce_count += 1
+
+
+      response['www-authenticate'] =~ /^(\w+) (.*)/
+
+      params = {}
+      $2.gsub(/(\w+)="(.*?)"/) { params[$1] = $2 }
+
+      a_1 = "#{user}:#{params['realm']}:#{password}"
+      a_2 = "#{@method}:#{@path}"
+      request_digest = ''
+      request_digest << Digest::MD5.new.update(a_1).hexdigest
+      request_digest << ':' << params['nonce']
+      request_digest << ':' << ('%08x' % @@nonce_count)
+      request_digest << ':' << CNONCE
+      request_digest << ':' << params['qop']
+      request_digest << ':' << Digest::MD5.new.update(a_2).hexdigest
+
+      header = []
+      header << "Digest username=\"#{user}\""
+      header << "realm=\"#{params['realm']}\""
+      
+      header << "qop=#{params['qop']}"
+
+      header << "algorithm=MD5"
+      header << "uri=\"#{@path}\""
+      header << "nonce=\"#{params['nonce']}\""
+      header << "nc=#{'%08x' % @@nonce_count}"
+      header << "cnonce=\"#{CNONCE}\""
+      header << "response=\"#{Digest::MD5.new.update(request_digest).hexdigest}\""
+
+      @header['Authorization'] = header
+    end
+  end
+end

spec/httparty/request_spec.rb

@@ -30,6 +30,17 @@ describe HTTParty::Request do
       @request.send(:setup_raw_request)
       @request.instance_variable_get(:@raw_request)['authorization'].should_not be_nil
     end
+
+    it "should use digest auth when configured" do
+      FakeWeb.register_uri(:head, "http://api.foo.com/v1",
+        :www_authenticate => 'Digest realm="Log Viewer", qop="auth", nonce="2CA0EC6B0E126C4800E56BA0C0003D3C", opaque="5ccc069c403ebaf9f0171e9517f40e41", stale=false')
+
+      @request.options[:digest_auth] = {:username => 'foobar', :password => 'secret'}
+      @request.send(:setup_raw_request)
+
+      raw_request = @request.instance_variable_get(:@raw_request)
+      raw_request.instance_variable_get(:@header)['Authorization'].should_not be_nil
+    end
   end
 
   describe "#uri" do
@@ -373,5 +384,25 @@ describe HTTParty::Request do
       }.should raise_error(ArgumentError)
     end
   end
+
+  describe "argument validation" do
+    it "should raise argument error if basic_auth and digest_auth are both present" do
+      lambda {
+        HTTParty::Request.new(Net::HTTP::Post, 'http://api.foo.com/v1', :basic_auth => {}, :digest_auth => {}).perform
+      }.should raise_error(ArgumentError, "only one authentication method, :basic_auth or :digest_auth may be used at a time")
+    end
+
+    it "should raise argument error if basic_auth is not a hash" do
+      lambda {
+        HTTParty::Request.new(Net::HTTP::Post, 'http://api.foo.com/v1', :basic_auth => ["foo", "bar"]).perform
+      }.should raise_error(ArgumentError, ":basic_auth must be a hash")
+    end
+
+    it "should raise argument error if digest_auth is not a hash" do
+      lambda {
+        HTTParty::Request.new(Net::HTTP::Post, 'http://api.foo.com/v1', :digest_auth => ["foo", "bar"]).perform
+      }.should raise_error(ArgumentError, ":digest_auth must be a hash")
+    end
+  end
 end