proxy.py and tls fingerprinting

[artemrts]

I use proxy.py for firefox web browser.
But if site is protected by cloudflare, then human verification occurs. W/o proxy.py this verification does not occur.
I thing this is due to tls fingerprint.
Is it possible to use something like https://github.com/niespodd/browser-fingerprinting
or any other tools for bypass this protection?
Thx.

[abhinavsingh]

Hi @artemrts , that's interesting and thanks for raising this up. We may need some investigation here, example:

• Check what TLS client hello is used by your browser
• Compare it with what occurs when routing via proxy.py

This will help us possibly narrow down the scenario and pin-point to differences which trigger a site challenge.

Possible for you to share the differences. You can use Wireshark or online fingerprint databases.

[artemrts]

Hi, @abhinavsingh
I am sorry, my fault. It was with mitmproxy, not proxy.py.
I have checked browser TLS Fingerprint/Akamai Hash with and without proxy.py - no changes. In principle, this is predictable.
It was in clear proxy mode, and I think we need to test proxy.py with TLS Interception, but I couldn't get it to work.

python3 -m proxy --hostname 10.10.10.1 --port 13301 --plugins proxy.plugin.ManInTheMiddlePlugin --ca-key-file /home/nginx/.mitmproxy/mitmproxy-ca-key.pem --ca-cert-file /home/nginx/.mitmproxy/mitmproxy-ca-cert.pem --insecure-tls-interception

I just used certificate and key from auto generated mitmproxy's certificate and key. This certificate already installed into Firefox.

Secure Connection Failed
An error occurred during a connection to ifconfig.me. SSL received a record that exceeded the maximum permissible length.
Error code: SSL_ERROR_RX_RECORD_TOO_LONG

What I m doing wrong?

[artemrts]

@abhinavsingh
Please, help. There is little information on this subject on the Internet.