No "HIGH" strength available without mcrypt

[remicollet]

trying to use getHighStrengthGenerator

PHP Fatal error: Uncaught RuntimeException: Could not find mixer in xxx/vendor/ircmaxell/random-lib/lib/RandomLib/Factory.php:237

It will be nice to have a "high" strength mixer, not from mcrypt (especially as this ext is now deprecated, and will be removed in 7.2)

P.S. perhaps an alternative option could be to be able to ask for "high" sources with "medium" mixer

[paragonie-scott]

This should be solved in https://github.com/paragonie/RandomLib.