How to create argon2 password hashes with axum_login?

When I manually create user records in my database, with passwords such as:

$argon2id$v=19$m=19456,t=2,p=1$h8H23N0TGnue7RFRVwaOH$AZkmgLWbRdU8shs3I20Y7q

the axum_login crate lets me authenticate successfully.

I've not been able to find out how to use axum_login to create these $argon2id... hashes. I need to be able to do this to add new users and allow existing users to change their passwords.

My thoughts are:

• There's a special trait which I need my PgAuthBackend to implement in order to get access to a function to argon2-hash passwords.
• I've missed a function in the documentation which I should be using.
• This task isn't done for me in axum_login and I need to find an argon2 library to do this job.

How do I turn plaintext passwords into argon2 hashes which will "just work" with axum_login?

Not exactly thing you're asking for, but I have found using the argon2 and password-hash crates directly in a /login endpoint, minting a JWT, putting that in request headers and requiring/extracting a valid one via a axum::extract::FromRequestParts in other endpoints that need auth to be less hassle than stateful session management.

How do I turn plaintext passwords into argon2 hashes which will "just work" with axum_login?

• Argon2::hash_password
• then serialize()
• then as_str()