Expose more of OpenSSL's KDFs in `crypto` (HKDF, scrypt, Argon2)

hauleth · June 22, 2026, 9:46pm

Issue on GitHub by yours truly

Exposé OpenSSL KDF/PHF functions in `crypto`

opened 04:50PM - 09 Sep 25 UTC

team:VM enhancement

**Is your feature request related to a problem? Please describe.** [OpenSSL 3.x… have added support for multiple key derivation functions (KDF) and password hash functions (PHF)][openssl-kdf]. These functions are required for any work related to passwords handling, which includes a lot of modern web infrastructure. The best way to access such functionality in current Erlang is via some kind of FFI (NIF or ports) or use unsafe PBKDF2 implemented in Erlang on top of `crypto:hash/2` function. It would be super useful if we could access these functions without requiring 3rd party NIF (which is PITA to deploy) or falling back to spawning external processes (and potentially leaking secrets via `ps`). As OpenSSL has such functionality built in now, we can "just" expose these, and it will make a lot of stuff much easier. [openssl-kdf]: https://docs.openssl.org/3.3/man3/EVP_KDF/ **Describe the solution you'd like** Have `crypto:kdf(Data, Key, Opts)` or similar function available, that will do the KDF/PHF computation. **Additional context** [OWASP Password Storage Cheatsheet](https://cheatsheetseries.owasp.org/cheatsheets/Password_Storage_Cheat_Sheet.html) which describe Argon2id as preferred algorithm for modern password storage.