Problems recording HTTPS with VuGen

Recently a client had an urgent request to monitor a HTTPS URL due to poor availability and performance. No problem, give me the URL and I’ll have the monitor set up and running in 10 minutes. However, a simple task turned into an investigation of Vugen certificates and Windows security patching.

For any HTTPS request Vugen would not show any events after code generation and the recording browser would show:

The recording environment was:

  • Vugen 11.04
  • Windows XP
  • Internet Explorer 7

As HTTPS requests worked from normal browsing the problem pointed towards a Certificate issue somewhere between Vugen and the requested site. Investigation discovered that a recent Windows Security patch ( now blocks all RSA certificates less than 1024 bits long.

This is a problem for Vugen as it uses RSA private key of length 512 bits in files wplusCA.crt and wplusCAOnly_.crt.

Note: In Vugen 11.50 these files are called 1.wplusCA_Expiration_2020.crt and wplusCAOnly_Expiration_2020.crt.

You can find the Vugen certificates in the following directory:

<LoadRunner installation folder>\bin\certs\

Fortunately HP are aware of the problem and have issued the following critical updates to increase the private key length to 2048 bits:

Note you will need a valid HP Support account to download these patches.

Tech tips from JDS