Provide means for retrieving configuration by identifier.

guacamole-ext/src/main/java/net/sourceforge/guacamole/net/auth/GuacamoleConfigurationDirectory.java

@@ -50,6 +50,21 @@ import net.sourceforge.guacamole.protocol.GuacamoleConfiguration;
  */
 public interface GuacamoleConfigurationDirectory {
 
+    /**
+     * Returns the GuacamoleConfiguration having the given identifier.
+     * 
+     * @param identifier The identifier of the GuacamoleConfiguration to
+     *                   return.
+     * @return The GuacamoleConfiguration having the given identifier, or null
+     *         if no such GuacamoleConfiguration exists.
+     * 
+     * @throws GuacamoleException If an error occurs while retrieving the
+     *                            configuration, or if access to the
+     *                            configuration is denied.
+     */
+    GuacamoleConfiguration getConfiguration(String identifier)
+            throws GuacamoleException;
+
     /**
      * Returns a Map containing all GuacamoleConfigurations. The keys of this
      * Map are Strings which uniquely identify each configuration.

guacamole-ext/src/main/java/net/sourceforge/guacamole/net/auth/simple/SimpleGuacamoleConfigurationDirectory.java

@@ -70,6 +70,12 @@ public class SimpleGuacamoleConfigurationDirectory
         this.configs = configs;
     }
     
+    @Override
+    public GuacamoleConfiguration getConfiguration(String identifier)
+            throws GuacamoleException {
+        return configs.get(identifier);
+    }
+
     @Override
     public Map<String, GuacamoleConfiguration> getConfigurations()
             throws GuacamoleException {