diff --git a/guacamole-ext/src/main/java/org/glyptodon/guacamole/net/auth/permission/ObjectPermissionSet.java b/guacamole-ext/src/main/java/org/glyptodon/guacamole/net/auth/permission/ObjectPermissionSet.java
index 490c5697d..fd8af692a 100644
--- a/guacamole-ext/src/main/java/org/glyptodon/guacamole/net/auth/permission/ObjectPermissionSet.java
+++ b/guacamole-ext/src/main/java/org/glyptodon/guacamole/net/auth/permission/ObjectPermissionSet.java
@@ -23,6 +23,7 @@
 package org.glyptodon.guacamole.net.auth.permission;
 
 import java.util.Collection;
+import java.util.Set;
 import org.glyptodon.guacamole.GuacamoleException;
 
 
@@ -121,4 +122,48 @@ public interface ObjectPermissionSet<IdentifierType> {
             Collection<ObjectPermission.Type> permissions,
             Collection<IdentifierType> identifiers) throws GuacamoleException;
 
+    /**
+     * Returns a Set which contains all permissions granted within this
+     * permission set.
+     *
+     * @return
+     *     A Set containing all permissions granted within this permission set.
+     *
+     * @throws GuacamoleException 
+     *     If an error occurs while retrieving permissions, or if permissions
+     *     cannot be retrieved due to lack of permissions to do so.
+     */
+    Set<ObjectPermission<IdentifierType>> getPermissions()
+            throws GuacamoleException;
+
+    /**
+     * Adds the specified permissions, if not already granted. If a specified
+     * permission is already granted, no operation is performed regarding that
+     * permission.
+     *
+     * @param permissions
+     *     The permissions to add.
+     *
+     * @throws GuacamoleException
+     *     If an error occurs while adding the permissions, or if permission to
+     *     add permissions is denied.
+     */
+    void addPermissions(Set<ObjectPermission<IdentifierType>> permissions)
+            throws GuacamoleException;
+
+    /**
+     * Removes each of the specified permissions, if granted. If a specified
+     * permission is not granted, no operation is performed regarding that
+     * permission.
+     *
+     * @param permissions
+     *     The permissions to remove.
+     *
+     * @throws GuacamoleException
+     *     If an error occurs while removing the permissions, or if permission
+     *     to remove permissions is denied.
+     */
+    void removePermissions(Set<ObjectPermission<IdentifierType>> permissions)
+            throws GuacamoleException;
+
 }
diff --git a/guacamole-ext/src/main/java/org/glyptodon/guacamole/net/auth/permission/SystemPermissionSet.java b/guacamole-ext/src/main/java/org/glyptodon/guacamole/net/auth/permission/SystemPermissionSet.java
index e106cbc08..8acefff8d 100644
--- a/guacamole-ext/src/main/java/org/glyptodon/guacamole/net/auth/permission/SystemPermissionSet.java
+++ b/guacamole-ext/src/main/java/org/glyptodon/guacamole/net/auth/permission/SystemPermissionSet.java
@@ -22,6 +22,7 @@
 
 package org.glyptodon.guacamole.net.auth.permission;
 
+import java.util.Set;
 import org.glyptodon.guacamole.GuacamoleException;
 
 
@@ -74,4 +75,49 @@ public interface SystemPermissionSet {
     void removePermission(SystemPermission.Type permission)
             throws GuacamoleException;
 
+    /**
+     * Returns a Set which contains all system-level permissions granted within
+     * this permission set.
+     *
+     * @return
+     *     A Set containing all system-level permissions granted within this
+     *     permission set.
+     *
+     * @throws GuacamoleException 
+     *     If an error occurs while retrieving permissions, or if permissions
+     *     cannot be retrieved due to lack of permissions to do so.
+     */
+    Set<SystemPermission> getPermissions() throws GuacamoleException;
+
+    /**
+     * Adds the specified permissions, if not already granted. If a specified
+     * permission is already granted, no operation is performed regarding that
+     * permission.
+     *
+     * @param permissions
+     *     The permissions to add.
+     *
+     * @throws GuacamoleException
+     *     If an error occurs while adding the permissions, or if permission to
+     *     add permissions is denied.
+     */
+    void addPermissions(Set<SystemPermission> permissions)
+            throws GuacamoleException;
+
+    /**
+     * Removes each of the specified permissions, if granted. If a specified
+     * permission is not granted, no operation is performed regarding that
+     * permission.
+     *
+     * @param permissions
+     *     The permissions to remove.
+     *
+     * @throws GuacamoleException
+     *     If an error occurs while removing the permissions, or if permission
+     *     to remove permissions is denied.
+     */
+    void removePermissions(Set<SystemPermission> permissions)
+            throws GuacamoleException;
+
+
 }
diff --git a/guacamole-ext/src/main/java/org/glyptodon/guacamole/net/auth/simple/SimpleObjectPermissionSet.java b/guacamole-ext/src/main/java/org/glyptodon/guacamole/net/auth/simple/SimpleObjectPermissionSet.java
index d0132780c..96a98b46a 100644
--- a/guacamole-ext/src/main/java/org/glyptodon/guacamole/net/auth/simple/SimpleObjectPermissionSet.java
+++ b/guacamole-ext/src/main/java/org/glyptodon/guacamole/net/auth/simple/SimpleObjectPermissionSet.java
@@ -78,20 +78,11 @@ public class SimpleObjectPermissionSet<IdentifierType>
         this.permissions = permissions;
     }
 
-    /**
-     * Returns the Set which currently backs this SimpleObjectPermissionSet.
-     * Changes to this Set will affect future function calls on this
-     * SimpleObjectPermissionSet.
-     *
-     * @return
-     *     The Set of permissions this SimpleObjectPermissionSet currently 
-     *     contains.
-     */
-    protected Set<ObjectPermission<IdentifierType>> getPermissions() {
+    @Override
+    public Set<ObjectPermission<IdentifierType>> getPermissions() {
         return permissions;
     }
 
-   
     @Override
     public boolean hasPermission(ObjectPermission.Type permission,
             IdentifierType identifier) throws GuacamoleException {
@@ -140,4 +131,16 @@ public class SimpleObjectPermissionSet<IdentifierType>
         
     }
 
+    @Override
+    public void addPermissions(Set<ObjectPermission<IdentifierType>> permissions)
+            throws GuacamoleException {
+        throw new GuacamoleSecurityException("Permission denied.");
+    }
+
+    @Override
+    public void removePermissions(Set<ObjectPermission<IdentifierType>> permissions)
+            throws GuacamoleException {
+        throw new GuacamoleSecurityException("Permission denied.");
+    }
+
 }
diff --git a/guacamole-ext/src/main/java/org/glyptodon/guacamole/net/auth/simple/SimpleSystemPermissionSet.java b/guacamole-ext/src/main/java/org/glyptodon/guacamole/net/auth/simple/SimpleSystemPermissionSet.java
index 5b027e5a9..bd6a5c2e0 100644
--- a/guacamole-ext/src/main/java/org/glyptodon/guacamole/net/auth/simple/SimpleSystemPermissionSet.java
+++ b/guacamole-ext/src/main/java/org/glyptodon/guacamole/net/auth/simple/SimpleSystemPermissionSet.java
@@ -72,16 +72,8 @@ public class SimpleSystemPermissionSet implements SystemPermissionSet {
         this.permissions = permissions;
     }
 
-    /**
-     * Returns the Set which currently backs this SimpleSystemPermissionSet.
-     * Changes to this Set will affect future function calls on this
-     * SimpleSystemPermissionSet.
-     *
-     * @return
-     *     The Set of permissions this SimpleSystemPermissionSet currently 
-     *     contains.
-     */
-    protected Set<SystemPermission> getPermissions() {
+    @Override
+    public Set<SystemPermission> getPermissions() {
         return permissions;
     }
 
@@ -106,4 +98,16 @@ public class SimpleSystemPermissionSet implements SystemPermissionSet {
         throw new GuacamoleSecurityException("Permission denied.");
     }
 
+    @Override
+    public void addPermissions(Set<SystemPermission> permissions)
+            throws GuacamoleException {
+        throw new GuacamoleSecurityException("Permission denied.");
+    }
+
+    @Override
+    public void removePermissions(Set<SystemPermission> permissions)
+            throws GuacamoleException {
+        throw new GuacamoleSecurityException("Permission denied.");
+    }
+
 }