RFR: 8331008: Implement JEP 478: Key Derivation Function API (Preview) [v15]

[Kevin Driver]

On Wed, 28 Aug 2024 18:41:52 GMT, Weijun Wang <weijun at openjdk.org> wrote:

>> src/java.base/share/classes/javax/crypto/spec/HKDFParameterSpec.java line 142:
>> 
>>> 140:          *     if {@code length} is not greater than 0
>>> 141:          */
>>> 142:         public ExtractThenExpand thenExpand(byte[] info, int length) {
>> 
>> If it is a fairly common use case to not have an `info` parameter, then I think we should add a method that does not take this parameter, i.e. `thenExpand(int length)`.
>
> Every time HKDF-Expand is used in either TLS 1.3 or HPKE, there is always a non-empty info. Even if the original RFC says this argument is optional, I don't think it's useful to provide a one-argument overloaded method.

Agreed.

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PR Review Comment: https://git.openjdk.org/jdk/pull/20301#discussion_r1735262757