RFR: 8317431: Implement simpler Comparator when building certification paths [v3]

[Weijun Wang]

On Thu, 11 Jan 2024 17:31:37 GMT, Sean Mullan <mullan at openjdk.org> wrote:

>> This enhancement simplifies and improves the performance of the Comparator that the PKIX CertPathBuilder uses to sort candidate certificates.
>> 
>> [RFC 5280](https://www.rfc-editor.org/rfc/rfc5280#section-4.2.1.1) requires that certificates include authority and subject key identifiers to facilitate cert path discovery. When the certificates comply with RFC 5280, the sorting algorithm is fast and efficient. However, there may be cases where certificates do not include the proper KIDs, for legacy or other reasons. This enhancement targets those cases and has shown an increase in performance of `CertPathBuilder.build` by up to 2x in tests involving certificates that do not contain KIDs. Specific changes include:
>> 
>> - Removed and simplified some of the steps in `PKIXCertComparator.compare` method. Some of these steps were not a good representation of common certificate hierarchies and were overly expensive to perform. 
>> - Several methods in `X500Name` and `Builder` have been made obsolete and thus removed.
>> - `X500Name` has been changed to use shared secrets instead of reflection to access non-public members of `X500Principal`, and vice-versa.
>> - The `CertificateBuilder` test code has been enhanced to set reasonable defaults for serial number and validity fields of a certificate
>
> Sean Mullan has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Fix whitespace error. Improve debugging. Change return value of distanceToCommonAncestor().

LGTM. Only 2 style comments for src and another for test.

src/java.base/share/classes/sun/security/provider/certpath/ForwardBuilder.java line 496:

> 494:             String debugMsg = null;
> 495:             if (debug != null) {
> 496:                 debug.println(METHOD_NME +" SAME NAMESPACE AS TRUSTED TEST...");

Add a space after `+`.

src/java.base/share/classes/sun/security/provider/certpath/ForwardBuilder.java line 509:

> 507:                 X500Name tSubjectName = X500Name.asX500Name(tSubject);
> 508:                 int d1 = distanceToCommonAncestor(tSubjectName, cIssuer1Name);
> 509:                 int d2 = distanceToCommonAncestor(tSubjectName, cIssuer2Name);

The logic below is correct. Somehow I think it will be clearer if you print out the debug lines before all the checks. Something like:

if (debug != null) {
    if (d1 != -1) debug.println(...);
    if (d2 != -1) debug.println(...);
}

test/jdk/sun/security/provider/certpath/PKIXCertComparator/Order.java line 58:

> 56:         kpg.initialize(2048);
> 57: 
> 58:         // Create top-level root CA cert with KIDs (Subject and Auth KeyIds)

Should a root CA have AKID?

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Marked as reviewed by weijun (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/17248#pullrequestreview-1829925340
PR Review Comment: https://git.openjdk.org/jdk/pull/17248#discussion_r1457589230
PR Review Comment: https://git.openjdk.org/jdk/pull/17248#discussion_r1457598419
PR Review Comment: https://git.openjdk.org/jdk/pull/17248#discussion_r1457613256