Add fingerprint / thumbprint support

[secana]

Hi! I try to use the authenticode-rs crate for a security application. I'm interested in parsing the signer certificates of PE files and validating their thumbprint/fingerprint.

I'm able to get the certificates from the authenticate signature, but there seems to be no option to get the fingerprint of the certificates, either for SHA-1 or SHA-256.

The authentic ode-parser crate exports the functionality here: https://docs.rs/authenticode-parser/0.5.0/authenticode_parser/struct.Certificate.html#method.sha1 and here https://docs.rs/authenticode-parser/0.5.0/authenticode_parser/struct.Certificate.html#method.sha256

Is there any chance to add the functionality to the crate or export the certificate in a way that the hash can be computed?

[nicholasbishop]

Hi, thanks for filing this. I haven't had much time to spend on this crate recently, but if you're interested in adding this functionality I'd be happy to review a PR.