mutual SSL Certificate Verify event

Hi,

in the context of mutual TLS, I'd like to intercept the certificate verify (digitally signed with client's cert private key) message sent by the client to the F5.

I could not find the appropriate event to look for - I've seen the CLIENT_HANDSHAKE but it does not seem to fit my need. Nor the others listed in the documentation.

How can I intercept and read that particular message? I want to be able to save it for revalidation of the key (troubleshooting+revalidation), but I cannot understand how to grab it in the first place.

Cheers, M