There is also another project that uses not just certificates but full TLS handshake fingerprints. The name escapes me, but it allows the server to determine wh

There is also another project that uses not just certificates but full TLS handshake fingerprints. The name escapes me, but it allows the server to determine whether it is talking to a browser, or the MitM proxy forwarding the connection. (You could of course employ a similar technique on the client side). Don't remember the name. Both approaches have advantages and disadvantages (e.g. this one reports false positives if the certificates change, the other either reports false positives if the fingerprints change unexpectedly, or false negatives/inconclusive results if it encounters an unknown fingerprint).