RFR: 8358594: Misleading keyLength value captured in JFR event for ML-KEM key [v2]

[Artur Barashev]

On Wed, 4 Jun 2025 16:50:41 GMT, Weijun Wang <weijun at openjdk.org> wrote:

>> src/java.base/share/classes/sun/security/util/KeyUtil.java line 62:
>> 
>>> 60:      * each standardized parameter set. For example, ML-KEM-768 is assigned to
>>> 61:      * category 3, and ML-DSA-87 to category 5.
>>> 62:      *
>> 
>> Should we consider returning whatever number is an the end of PQC algorithms as a key size? That would make things consistent and it would allow us to use existing `keySize` algorithm constraints for PQC algorithms. Key sizes for RSA and EC algorithms already differ significantly for the same security level: 3072-bit RSA corresponds to 256-bit EC. So we can return `768` for ML-KEM-768 or `87` for ML-DSA-87.
>
> For ML-DSA-87, 87 isn’t a key size in any sense. Using it as a key size would be misleading. For algorithm constraints, we can use the parameter set name directly.

Right, we should probably consider renaming `getKeySize()` to `getKeyStrength()`, but I guess that would be outside of this PR's scope.

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PR Review Comment: https://git.openjdk.org/jdk/pull/25642#discussion_r2127131876