SSL Decryption Certificate Issues

[Millette]

I have created the SSL decryption certificate and applied it using group policy. When testing I have several workstations that work with no issue but many others that recieve certificate errors. I cannot find any difference in the browser setup, the SSL certificate is in the workstation trusted root store where it should be. It looks like a 50/50 success rate. Windows 10 workstations, some on 1809 and some on 1903 with the same mixed results. I am at a loss, anybody had this issue?

[BPry]

@Millette,

What browser are you using for these tests? Some browsers will not, by default, look at the machines certificate store and will use their own. 

[Millette]

IE is our primary browser but we also use Chrome.

[Millette · Accepted solution]

So I believe I amy have to solution figured out. In the certificate options there is a box for root certificate. None of the instructions I read referenced that, but after checking that and re-deploying the certificate my sucess rate is 100%.

[BPry]

@Millette,

Odd that the guide you were following left that out, as it's a requirement to get this to function correctly. If you allow the installation of Firefox you'll also need to utilize the ESR version or do a little bit of manual work for FireFox to trust your cert; by default FireFox will not read the Windows cert store.