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Small Systems Notebook

Working notes on running small web services without drama.

Reading a handshake trace

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Reading a handshake trace
What each message in a TLS 1.3 handshake is for, in plain words.

The client hello carries the name of the site and the key shares; the server answers with its share, then everything after that is encrypted. The certificate travels inside the encrypted part, which is why a passive observer sees the name but not the certificate.

Session tickets arrive after the handshake has finished. They are small, but their size depends on the server software, so two servers configured differently can be told apart by them alone.

#tls#http