Function compare_reference_digest 

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

Compare a retained original reference with a retained original artifact. EN319132-1 A.1.1/A.1.2/A.1.3/A.1.4 use whole certificate/CRL DER and whole OCSPResponse, NOT merely its BasicOCSPResponse payload. https://www.etsi.org/deliver/etsi_en/319100_319199/31913201/01.03.01_60/en_31913201v010301p.pdf

Reuses the existing streaming/method/width/MD5 core without serialization, copying, implicit acquisition or a second algorithm dispatcher. Source retention alone does not certify valid DER; parse/authenticate the actual material through the material/PKIX pipeline separately. Neither agreement nor a URI proves incorporation, issuer identity, path use or a baseline.