Description of the protocol used to access GPGSM.
GPGSM does implement the Assuan protocol and in addition
provides a regular command line interface which exhibits a full client
to this protocol (but uses internal linking). To start
gpgsm as a server the command line the option
--server must be used. Additional options are provided to
select the communication method (i.e. the name of the socket).
We assume that the connection has already been established; see the Assuan manual for details.