Do intermediate certificates get cached in Firefox?

Question

If someone visits site A which has a certificate issues by GoDaddy which also supplied a intermediate certificate between GoDaddy and their CA, would Firefox cache the intermediate certificate and use it with site B which also has a GoDaddy issued certificate but doesn't provide an intermediate certificate? Causing the latter case not to give an SSL error?

The reasons why I ask is that we had an SSL issue on 3 out of 13 computers all with new versions of Firefox on a server that I believe wasn't issuing an intermediate certificate.

Also while testing with a fake server and providing a corrected certificate setup, the issue went away when switching back to the real server.

Answer 1

Better late than never. Yes, browsers will cache intermediate certificates, and use them between different sites. Because of that, if you are missing the intermediate certificate, random users will receive a trust error, while others won't.

For example, in Firefox, it will be cached in a file called cert8.db (in your profile folder). To test this, either manually remove the file, or create a new profile in firefox.