Function compare_reference_target 

pub fn compare_reference_target<'p, X: BinaryXml, P: DigestProvider<'p, X>, W: Work>(
    xml: &X,
    references: &ReferenceProperty<X::Id, X::Document, X::Generation>,
    index: usize,
    target: ReferenceTarget<'_, '_, X::Id, X::Document, X::Generation>,
    provider: &'p P,
    execution: &W,
) -> BinaryResult<ReferenceDigest, X, ReferenceDigestError<P::Error>>

Compare an original reference against an actual external parsed certificate or CRL, or a retained whole XML envelope, through the SAME digest kernel. External acquisition/path trust stays with the caller; only the CURRENT operation pays this comparison and original storage ownership is unchanged. This does not imply that an external value is incorporated in the signature. The Annex A full-DER/whole-response and separate identifier obligations are identical to compare_reference_digest; no basic-only OCSP hash is allowed.