Ideally, I only need a simple SSLSocketChannel.
SSLSocketChannel
I already have a component that reads and writes message over ordinary SocketChannel, but for
SocketChannel
Jetty has an NIO SSL implementation for their server: SslSelectorChannelConnector. You might want to peek at it for details on what its doing.
There is also an old (but decent) article from O'Reilly that explains the details about NIO + SSL along with example code.