sslfollow
Extracts AES etc. keys from TLS connections, via ld_preload. This only works for browsers which make use of NSS. It used to work with chromium, but it seems they have now switched to BoringSSL. It still works with Firefox.
I have bundled some headers which are missing from the libnss3-dev package, to save having to grab them
Just do
sudo apt-get install libnss3-dev
make
LD_PRELOAD="./follow.so" firefox