Hidden Service Descriptor
*************************

Parsing for Tor hidden service descriptors as described in Tor’s
version 2 and version 3 rend-spec.

Unlike other descriptor types these describe a hidden service rather
than a relay. They’re created by the service, and can only be fetched
via relays with the HSDir flag.

These are only available through the Controller’s
"get_hidden_service_descriptor()" method.

**Module Overview:**

   BaseHiddenServiceDescriptor - Common parent for hidden service descriptors
     |- HiddenServiceDescriptorV2 - Version 2 hidden service descriptor
     +- HiddenServiceDescriptorV3 - Version 3 hidden service descriptor
          |- address_from_identity_key - convert an identity key to address
          |- identity_key_from_address - convert an address to identity key
          +- decrypt - decrypt and parse encrypted layers

   OuterLayer - First encrypted layer of a hidden service v3 descriptor
   InnerLayer - Second encrypted layer of a hidden service v3 descriptor

New in version 1.4.0.
