Bouncy Castle 1.80 accepted an incorrect CRL Number value

[onepeople158]

Hello Developer, I have a CRL file with a CRL number value of -36. According to RFC5280, the CRL number should be a non-negative integer, but Bouncy Castle 1.80 successfully printed this CRL without any errors.May I ask if this is a bug?

Code:

import java.io.InputStream;
import java.io.FileInputStream;
import org.bouncycastle.asn1.x509.CertificateList;
import org.bouncycastle.cert.X509CRLHolder;
import org.bouncycastle.asn1.ASN1ObjectIdentifier;
import org.bouncycastle.asn1.x509.Extension;
import org.bouncycastle.asn1.ASN1Primitive;
import org.bouncycastle.asn1.ASN1OctetString;
import org.bouncycastle.asn1.DEROctetString;
import org.bouncycastle.asn1.ASN1OctetStringParser;

public class CRLParserExample_serial_num {
    public static void main(String[] args) throws Exception{
            
            InputStream inputStream = new FileInputStream("crl_file_test_.der");
            
            X509CRLHolder crlHolder = new X509CRLHolder(inputStream);
            
            ASN1ObjectIdentifier oid = new ASN1ObjectIdentifier("2.5.29.20"); 
            
            Extension extension = crlHolder.getExtension(oid);

            System.out.println(extension.getParsedValue());

        } 
}

Test Cases:

crl_file_test_.zip

[dghgit]

Think of it as a feature.