NIST FF1 CLI tool. Uses input files consisting of one (large) hex string.
Key creation: $ openssl rand -hex 32 > key. Tweak creation: $ openssl rand -hex 8 > tweak.
Every message needs a new tweak.
Input message must consist of one (large) hex line, created with xxd, or my base16 encoder/decoder, with line length set to 0.