wireshark decrypt ssl client certificate

So, unless you can access those keys, there is no way to decrypt the SSL/TLS connections between Client -> Firewall.īTW: What you are installing on the clients is the CA cert of the firewall to prevent certificate warnings in the browser. I know only one or two firewalls that expose these temp keys via CLI. Now, here is your problem: You also don't know the temp private keys generated by the firewall privkey_fw(S), as that's only stored on the firewall itself. To be able to decrypt a SSL/TLS session with Wireshark, you need the private key of the 'remote' SSL/TLS endpoint.Īs you don't know the real private key of the server (unless you are the server admin), you cannot decrypt the connection between Firewall -> Server. This enables the firewalls to inspect the data, because it has access to the clear text payload 'between' the two SSL/TLS connections. two: from Firewall -> Server with privkey(S).one: from Client -> Firewall with privkey_fw(S).The firewall completes the SSL/TLS handshake using cert_fw(S) AND privkey_fw(S).Īfter that, you will have two SSL/TLS connections.So we have cert_fw(S) and privkey_fw(S), the cert + the private key created by the firewall to be used in the handshake for the client

The Firewall on-the-fly generates a new certificate signed with it's own CA cert, with the whole content of the external cert, but with a different private key (obviously).As part of the handshake the firewall receives cert(S), which is the certificate of the server S.The firewall itself opens a new SSL/TLS session to the target server S.The firewall intercepts that request (explicit proxy or transparent proxy) and let's the client wait.The client tries to access an external HTTPS site.private key) on the firewall, either generated on the Firewall or uploaded as PKCS#12 container. It will explain why you can't decrypt the traffic. Here is how SSL/TLS inspection works on a firewall.

Wireshark decrypt ssl client certificate