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Groovy Script: Get SSL Cipher and CLIBuilder Example

A couple weeks ago, I published a basic Perl script that will display the cipher used when an SSL Handshake between client and server is completed.  This is the (mostly-) groovy version of that script.

It's a little nicer than the Perl one right now because you can insert any of the available JSSE ciphers to see if that particular cipher will work.  You will need to input a valid cipher but case is not important as I am converting the cipher to Upper Case.  This initial version has no error or exception handling—that will come later when I figure out how to do it well.  This script also provides a pretty fair example of command line argument parsing in Groovy with CliBuilder. (Many thanks to this article on Mike's Musings for the writeup on CliBuilder)

#!/usr/bin/env groovy
Written by Chris Mahns, 2009 with an awful lot of help from this article:

This script will report back the SSL cipher used to negotiate
the connection between your workstation and a remote ssl server.

You can override, with the -c (or --cipher) switch to test using a 
specific cipher. Case is not important when setting the cipher as
it will be converted to Upper Case by the script.

import javax.net.ssl.*

// This section sets up the command line arguments portion
// of this script.
def cli = new CliBuilder( usage: 'getCipher [-h "hostname"] [-p "port"] [-c "cipher"] ' )
 cli.h( longOpt:'host', args:1, required:true, type:GString, 'The host or site you want to test' )
 cli.p( longOpt:'port', args:1, required:false, type:GString, 'The ssl port. Default is 443')
 cli.c( longOpt:'cipher', args:1, required:false, type:GString, 'Optionally, test with a specific cipher')

def opt = cli.parse(args)
 if (!opt) return
 if (opt.h) host = opt.h
 if (opt.c) cipher = (opt.c).toUpperCase()

def port = 443
 if (opt.p) port = Integer.parseInt(opt.p)

// Create the socket
def factory = SSLSocketFactory.getDefault() 
def socket = factory.createSocket("$host", port)
 if (opt.c) {
 else {

socket.addHandshakeCompletedListener( new listener() )

class listener implements HandshakeCompletedListener {
 void handshakeCompleted(HandshakeCompletedEvent e) {
 println('Handshake succesful!')
 println('Cipher suite used: ' + e.getCipherSuite())

For those of you interested in getting a copy of the script and don't feel like copying and pasting, head over to the Downloads page.


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