From the jTDS\README.SSL file:
At this point it should be noted that the solution has been tested against SQL
Server 2000 (SQL2K), and nothing else. Everything in this section applies to SQL
Server 2000. Having said that, the changes made to support SSL will not affect
the behavior of jTDS with other products when using plain sockets.
So SSL is not supported for SAP ASE in jTDS.