private int readRemaining( ByteBuffer dst ) throws SSLException {
		if( inData.hasRemaining() ) {
			return transfereTo( inData, dst );
		}
		if( !inData.hasRemaining() )
			inData.clear();
		// test if some bytes left from last read (e.g. BUFFER_UNDERFLOW)
		if( inCrypt.hasRemaining() ) {
			unwrap();
			int amount = transfereTo( inData, dst );
			if( amount > 0 )
				return amount;
		}
		return 0;
	}