diff --git a/src/authm_mad/one_auth_mad.rb b/src/authm_mad/one_auth_mad.rb
index 1c936ca0d2..6832e7cafc 100755
--- a/src/authm_mad/one_auth_mad.rb
+++ b/src/authm_mad/one_auth_mad.rb
@@ -51,6 +51,7 @@ class AuthorizationManager < OpenNebulaDriver
         database_url=@config[:database]
         @db=Sequel.connect(database_url)
         
+        # Get authentication driver
         begin
             driver_prefix=@config[:authentication].capitalize
             driver_name="#{driver_prefix}Auth"
diff --git a/src/authm_mad/simple_auth.rb b/src/authm_mad/simple_auth.rb
index 4a07db3014..00bec0b3f5 100644
--- a/src/authm_mad/simple_auth.rb
+++ b/src/authm_mad/simple_auth.rb
@@ -19,7 +19,7 @@
 class SimpleAuth
     # Method called by authentication driver. It should awnser true if
     # successful or a string with the error message if failure. All
-    # parameters are string extracted from the authorization message.
+    # parameters are strings extracted from the authorization message.
     #
     # * user_id: OpenNebula user identifier
     # * user: user name
diff --git a/src/authm_mad/simple_permissions.rb b/src/authm_mad/simple_permissions.rb
index 81862e302f..b055779230 100644
--- a/src/authm_mad/simple_permissions.rb
+++ b/src/authm_mad/simple_permissions.rb
@@ -9,10 +9,13 @@ class SimplePermissions
         @quota_enabled=conf[:quota][:enabled]
     end
     
+    # Returns message if result is false, true otherwise
     def auth_message(result, message)
         result ? true : message
     end
     
+    # Extracts cpu and memory resources from the VM template sent in
+    # authorization message
     def get_vm_usage(data)
         vm_xml=Base64::decode64(data)
         vm=OpenNebula::VirtualMachine.new(
@@ -31,6 +34,7 @@ class SimplePermissions
         VmUsage.new(cpu, memory)
     end
     
+    # Method called by authorization driver
     def auth(uid, tokens)
         result=true
         
@@ -43,6 +47,8 @@ class SimplePermissions
         result
     end
     
+    # Authorizes each of the tokens. All parameters are strings. Pub
+    # means public when "1" and private when "0"
     def auth_object(uid, object, id, action, owner, pub)
         return true if uid=='0'