RFR: JDK-8300416 java.security.MessageDigestSpi clone can result in thread-unsafe clones [v2]

[Sean Mullan]

On Wed, 1 Feb 2023 17:56:05 GMT, Mark Powers <mpowers at openjdk.org> wrote:

>> test/jdk/java/security/MessageDigest/TestCloneable.java line 95:
>> 
>>> 93: 
>>> 94:         System.out.println(": Shared data check");
>>> 95:         if (!Arrays.equals(d1.digest(), d2.digest())) {
>> 
>> If d1 and d2 don't share memory and each thread processes random bytes, how can the digests be equal?
>
> In the case where ByteBuffer has allocated a direct buffer, a new internal byte array gets allocated. This is the shared memory that's causing the problem. See MessageDigestSpi.java line 220.
> 
> Oops got to update the copyright.

I think you mean line 126? :

`                tempArray = new byte[n];  `

-------------

PR: https://git.openjdk.org/jdk/pull/12348