Is that allowed? 
https://cryptoslate.com/professor-re-uploads-tornado-cash-code-to-github-for-research-purposes/
"Professor re-uploads Tornado Cash code to GitHub for research purposes
A professor of Computer Science at Johns Hopkins University re-uploaded Tornado Cash and Tornado Nova source codes to GitHub, saying he has been using the code for teaching purposes."
I think under the for teaching and research disclaim might let our dear professor scoot free from the sanction by the U.S. Government. Unless the government can proof it causes harm by simply observing the code which is just a bunch of combinations of 1 and 0.https://cryptoslate.com/professor-re-uploads-tornado-cash-code-to-github-for-research-purposes/
"Professor re-uploads Tornado Cash code to GitHub for research purposes
A professor of Computer Science at Johns Hopkins University re-uploaded Tornado Cash and Tornado Nova source codes to GitHub, saying he has been using the code for teaching purposes."