Testing requires a tool and for one of my projects I'm using JMeter. I'm testing an https based site and was just having a hard time figuring out what was going on. I kept seeing an error in the JMeter "view results tree" that just said "ensure browser is set to accept the jmeter proxy certificate". I started researching that phrase and got nowhere quickly.
However, in the jmeter/bin subdirectory I found the jmeter.log file. In there I found a java.security.NoSuchAlgorithmException and referencing the SunX509 KeyManagerFactory. Ah ha, yes, I'm running the IBM JRE and not the Sun version.
Unfortunately changing the jmeter.properties proxy.cert.factory=IbmX509 (and of course uncommenting it) had no effect and I got the same SunX509 exception. I decided to try it at the command line as:
jmeterw -Dproxy.cert.factory=IbmX509 and voila the problem went away!