Thank you so much, I wasted roughly 12 hours trying to get something to work where python signed a message that a PHP script on a different machine could properly and safely verify. I was messing around with phpecc (github project) and other stuff and was getting rather frustrated.
Saw the post on libsodium in php 7.2, built the PECL module for PHP 7.1 and the python library pysodium - and within an hour had something that actually worked with very little code.
Again, thank you so much. With the convoluted stuff I was trying, I was really afraid my app would end up being an example in the wild where cryptography went bad because the developer messed up.