open_auth support for libvirt fog provider

open_auth.diff

diff --git a/lib/fog/compute/libvirt.rb b/lib/fog/compute/libvirt.rb
index 323c362..930be4f 100644
--- a/lib/fog/compute/libvirt.rb
+++ b/lib/fog/compute/libvirt.rb
@@ -41,7 +41,18 @@ module Fog
           require 'libvirt'

           begin
-            @connection = ::Libvirt::open(@uri.uri)
+            if options[:user] and options[:password]
+              @connection = ::Libvirt::open_auth(@uri.uri, [::Libvirt::CRED_AUTHNAME, ::Libvirt::CRED_PASSPHRASE]) do |cred|
+                if cred['type'] == ::Libvirt::CRED_AUTHNAME
+                  res = options[:user]
+                elsif cred["type"] == ::Libvirt::CRED_PASSPHRASE
+                  res = options[:password]
+                else
+                end
+              end
+            else
+              @connection = ::Libvirt::open(@uri.uri)
+            end
           rescue ::Libvirt::ConnectionError
             raise Fog::Errors::Error.new("Error making a connection to libvirt URI #{@uri.uri}:\n#{$!}")
           end