DefaultDigestAlgorithmIdentifierFinder throws NPE for Composite Sigs

[Akretsch]

org.bouncycastle.operator.DefaultDigestAlgorithmIdentifierFinder.find(MiscObjectIdentifiers.id_MLDSA44_RSA2048_PSS_SHA256) triggers NullPointerException("digest OID is null") in
org.bouncycastle.operator.DefaultDigestAlgorithmIdentifierFinder.find(ASN1ObjectIdentifier).

I would expect org.bouncycastle.operator.DefaultDigestAlgorithmIdentifierFinder.find(MiscObjectIdentifiers.id_MLDSA44_RSA2048_PSS_SHA256) returning null in such case.

[roy-basmacier]

Hello @Akretsch,
I tried reproducing the error, but

org.bouncycastle.operator.DefaultDigestAlgorithmIdentifierFinder.find(MiscObjectIdentifiers.id_MLDSA44_RSA2048_PSS_SHA256)

is returning the corresponding AlgorithmIdentifier.

Can you provide more information on how you are producing the NPE

[Akretsch]

Sorry, my code was not complete. This snippet triggers the NPE:

package com.siemens.pki.bctest;

import org.bouncycastle.asn1.x509.AlgorithmIdentifier;
import org.bouncycastle.operator.DefaultDigestAlgorithmIdentifierFinder;
import org.bouncycastle.operator.DigestAlgorithmIdentifierFinder;

public class FinderTest {

	private static final DigestAlgorithmIdentifierFinder DIG_ALG_FINDER = new DefaultDigestAlgorithmIdentifierFinder();

	public static void main(String[] args) {
		try {
			System.out.println(DIG_ALG_FINDER
					.find(new AlgorithmIdentifier(
							org.bouncycastle.asn1.misc.MiscObjectIdentifiers.id_MLDSA44_RSA2048_PSS_SHA256))
					.getAlgorithm());
		} catch (NullPointerException ex) {
			ex.printStackTrace();
		}
	}
}

I use the 1.79-SNAPSHOT version.

[roy-basmacier]

Hello @Akretsch,
Thanks for sharing the code snippet. I was able to recreate it.

I would expect org.bouncycastle.operator.DefaultDigestAlgorithmIdentifierFinder.find(MiscObjectIdentifiers.id_MLDSA44_RSA2048_PSS_SHA256) returning null in such case.

Should the expected value be the Digest Algorithm Identifier used by the CMS signer?
Or would it be more reasonable to return null?

[Akretsch]

Hello @roy-basmacier,

I have to deal with certHash generation in CMP cert confirmations, see
https://www.ietf.org/archive/id/draft-ietf-lamps-rfc4210bis-12.html#section-5.3.18 . So if a certificate signature algorithm does not specify or enforce a specific hash algorithm, the DefaultDigestAlgorithmIdentifierFinder shall return null.

But maybe CMS needs it in another way?

Thanks for testing!

Andreas