I was trying to find a pure-Rust implementation of RFC 5280 and it seems like cryptography-x509-verification is one of the few implementations out there, if not the only one that actually exposes all of the necessary functionality. The blogpost about the implementation seems to confirm my suspicion.
Unfortunately it's rather tedious to utilize the code outside of using cryptography in Python, especially when trying to avoid OpenSSL (due to WASM targets), which is a huge pity.
Have you considered publishing these core Rust libraries as standalone crates so that other (Rust or Python) projects could utilize them?