I've been sitting on this code since the Bitfi debacle of 2018 - John McAfee was spokestroll for an "unhackable" cryptocurrency wallet, and long story short Saleem Rashid and I built a reliable key extraction exploit and withheld the details out of spite.
https://gist.github.com/ryancdotorg/278dd8d696a3d01761f30410d7d42bb5