Example ImportTLSClientHelloFromJSON about utls HOT 6 OPEN

I appreciate the fast reply, that helped a lot.

For anyone who comes along with this question, it was easy to do this via Wireshark by just grabbing a ClientHello packet from the browser I wanted to fingerprint, and exporting the packet bytes of specifically the TLS frame.

from utls.

Ah, i see now that this was brought up a few months ago here.

So, I suppose that answers my question. A better question would be, has any momentum been built around this feature since?

from utls.

We haven't been able to focus on this feature yet since there are much more to be done with TLSfingerprint.io... It is not too bad (see an example here) and we just need more time to actually start working on it ;)

from utls.

Just to clarify, the ImportTLSClientHelloFromJSON is meant to allow user importing an existing (known and prerecorded) ClientHello from a database.

The major blocker on this is that we have to make some modifications to TLSfingerprint.io before we can fully support this feature. For now the database from TLSFingerprint.io does not record that many different fields that do not impact the result hash on the website (e.g., the content of ApplicationSettings) but subject to be fingerprintable. It is not a very trivial work as the database might need to be redesigned into an extensible structure, and we DO need stronger database servers 😄

I see you are trying to replicate the ClientHello of your web browser. In which case you might just want to use func (f *Fingerprinter) RawClientHello(raw []byte) (clientHelloSpec *ClientHelloSpec, err error) which takes your ClientHello message as raw bytes.

from utls.

And we are also planning to support importing directly from https://client.tlsfingerprint.io/, which would be much easier to achieve since we will not have to modify the database.

from utls.

Just a reminder that the ClientHello you grab from your pcap may or may not fully cover the "ClientHello space" of a TLS client.

For example, Chrome shuffles the TLS extensions list and use a few different combinations of settings in ECH.

from utls.