Archive for tag "Cypher"

Debugging cyphered connections is a hassle, but Wireshark can occasionally help. I recently spent a few hours trying to debug a Jetty server that insisted on speaking HTTPS.

First, I had to convert the Java Key Store to something Wireshark could consume: a PEM file. A fairly simple tutorial, should have been enough, but a GUI-based key store manager proved to be indispensable. Then I realized that Diffie-Hellman is the sworn enemy of network monitors everywhere, as illustrated by Wireshark’s SSL debugging output:

ssl_generate_keyring_material not enough data to generate key (0×16 required 0×37 or 0×57)
dissect_ssl3_hnd_srv_hello can’t generate keyring material

Of course, if you’re in control of the Jetty server in question, then you can use org.mortbay.jetty.security.SslSocketConnector.setExcludeCipherSuites() to prevent pesky DHE. Then it’s Wireshark all the way!