Sorry if I’m misunderstanding, but are you saying you want to effectively copy Discourse’s hashing algorithm to your own app so you can match the hashes your app generates against those stored by Discourse? Wouldn’t this require you to regularly sync the passwords from Discourse to your htpasswd file, handle salts that Discourse may or may not have now or in the future, and keep your implementation of the hashing algorithm in sync with Discourse’s algorithm forever?
Again, sorry if I’m completely misunderstanding, but I had to ask for clarification for my own curiosity.