Class SpecialPermission

All Implemented Interfaces:
Serializable, Guard

public final class SpecialPermission extends BasicPermission
Elasticsearch-specific permission to check before entering AccessController.doPrivileged() blocks.

We try to avoid these blocks in our code and keep security simple, but we need them for a few special places to contain hacks for third party code, or dangerous things used by scripting engines.

All normal code has this permission, but checking this before truncating the stack prevents unprivileged code (e.g. scripts), which do not have it, from gaining elevated privileges.

In other words, don't do this:


   // throw away all information about caller and run with our own privs
   AccessController.doPrivileged(
    ...
   );
 

Instead do this;

   // check caller first, to see if they should be allowed to do this
   SecurityManager sm = System.getSecurityManager();
   if (sm != null) {
     sm.checkPermission(new SpecialPermission());
   }
   // throw away all information about caller and run with our own privs
   AccessController.doPrivileged(
    ...
   );
 
See Also:
  • Field Details

  • Constructor Details

    • SpecialPermission

      public SpecialPermission()
      Creates a new SpecialPermission object.
    • SpecialPermission

      public SpecialPermission(String name, String actions)
      Creates a new SpecialPermission object. This constructor exists for use by the Policy object to instantiate new Permission objects.
      Parameters:
      name - ignored
      actions - ignored
  • Method Details