View this package for all Ubuntu releases →

How to install sw-nginx-module-handshake-padding in Ubuntu 26.04 (resolute) (amd64)

TLS 1.3 handshake record padding against ECH vhost fingerprinting

Install

curl -fsSL https://extras.getpagespeed.com/release-latest.deb -o /tmp/getpagespeed-release.deb
sudo apt-get install -y /tmp/getpagespeed-release.deb
rm /tmp/getpagespeed-release.deb
sudo apt-get update
sudo apt-get install -y sw-nginx-module-handshake-padding

Installing packages requires an active GetPageSpeed subscription. For other releases and channels, use the setup wizard.

Description

Pads outgoing TLS 1.3 handshake records to a multiple of a configured block size, so that virtual hosts sharing an ECH (Encrypted Client Hello) listener cannot be told apart by the exact record sizes of their encrypted server handshake flight. This is the server-side mitigation RFC 9849 section 6.1.3 calls for: without it, a single byte of certificate difference uniquely identifies a vhost behind an ECH cover. One directive: ssl_handshake_padding (default off, recommended 512). Zero application-data overhead, KTLS-compatible; requires nginx running against OpenSSL 3.4+; HTTP/3 handshakes are not covered by the underlying OpenSSL API.

Packages

Subscribe