Function verify_thumbprint 

pub fn verify_thumbprint<'a>(
    cert: &Certificate,
    thumbprints: impl IntoIterator<Item = &'a str>,
    now: SystemTime,
) -> Result<SystemTime, Failure>

Checks validity period and thumbprint allow-list, returns notAfter.

Errors

Failure::NotYetValid, Failure::Expired or Failure::ThumbprintMismatch.