Forum Discussion
elemzy
Altostratus
AltostratusCRL or OSCP in SSLO
Hi Can someone explain to me if and how SSLO does CRL checks? I assume that it should automatically perform these certificate revocation checks on behalf of the client since it proxies the client's...
elemzyAltostratus
AltostratusThanks, Kevin,
Configured OCSP as described but it doesn't work with my test site "revoked[.]badssl[.]com". Still waiting for F5 support to help figure out why.
- Kevin_Stewart
Employee
revoked.badssl.com probably isn't a good test. Server side OCSP will attempt to perform one of two functions:
- An OCSP stapling request, in which the BIG-IP sends a status_request message in the TLS handshake and expects to receive an OCSP stapled response.
- If the above doesn't work, the BIG-IP will attempt to read the AIA field from the server cert and do a direct OCSP request.
revoked.badssl.com neither participates in OCSP stapling nor contains an AIA field. A better option would be revoked.grc.com. You can see the cert attributes like this:
echo | openssl s_client -connect revoked.badssl.com:443 -showcerts 2>&1 |sed -n '/-BEGIN CERTIFICATE-/,/-END CERTIFICATE-/p' |openssl x509 -noout -text echo | openssl s_client -connect revoked.grc.com:443 -showcerts 2>&1 |sed -n '/-BEGIN CERTIFICATE-/,/-END CERTIFICATE-/p' |openssl x509 -noout -text- elemzy
Hi Kevin,
I see the difference between both sites on the F5, but I did find an AIA field in the revoked.badssl.com certificate in both firefox and edge.
I also got a response from F5 support, and I was asked to change the "Trusted Responders" field to none. SSL started blocking revoked.badssl.com after this change, and I got the following in my log "Certificate with subject name (/CN=revoked.badssl.com) and serial number (0X0D2E67A298853B9A5452E3A285A4572F) is revoked"
I asked for the rationale behind this change, but I've not gotten a response.
