“gnutls_handshake() failed(): A TLS packet with unexpected length was receive” at school

Question

This problem happens on my Ubuntu 12.04, Git version 1.7.9.5

There appears always an error message "error: gnutls_handshake() failed: A TLS packet with unexpected length was receive..." while I am using Git with HTTPS protocol via the network of our school.

According to the result of parsing the packet with Wireshark, the Git-client sends a Hello packet via SSL protocol in the fourth step, and receives in the fifth step a RST/ACK error.

But in the normal networking environment, Git sends a Hello packet via TLSv1 protocol in the fourth step and then works like a charm after receiving the ACK packet.

I would like to check out where the problem happens in our weird network environment, or is it caused by Git?

The attachments are the results from Wireshark in both network environments:

Wrong environment

Correct environment

Answer 1

It really looks like you have something messing with your HTTPS traffic.

I encountered this message when dealing with networks with captive portal authentication or proxies that try to snoop on your traffic by sending you a custom certificate.