typedef struct SilcProtocolStruct { ... } *SilcProtocol;

    The actual protocol object. This is allocated by the silc_protocol_alloc
    and holds the information about the current protocol. Information
    such as the current state, execution callback and final callback.
    The context is freed by silc_protocol_free function.

    Short description of the field following:

    SilcProtocolObject *protocol

      This is the pointer to the SilcProtocolObject and holds the
      protocol specific information.

    SilcProtocolState state

      Protocol state. The state of the protocol can be changed in the
      callback function.

    void *context

      Context to be sent for the callback function. This is usually 
      object for either SILC client or server. However, this abstraction 
      makes it possible that this pointer could be some other object as
      well. Note that the context is not delivered in any callback 
      function. Application can access it through this context.

    SilcProtocolFinalCallback final_callback;

      This is a callback function that is called with timeout _after_ the
      protocol has finished or error occurs. If this is NULL, naturally 
      nothing will be executed. Protocol should call this function only at 
      SILC_PROTOCOL_STATE_END and SILC_PROTOCOL_STATE_ERROR states.