RFR: 8331008: Implement JEP 478: Key Derivation Function API (Preview) [v11]

[Valerie Peng]

On Fri, 16 Aug 2024 18:09:02 GMT, Valerie Peng <valeriep at openjdk.org> wrote:

>> Kevin Driver has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   addressed several review comments, namely: - renaming the getParameters method - renaming the AlgorithmParameterSpec object - address some javadoc exception messages - add some information to KDF class private constructor javadocs - other general cleanup
>
> src/java.base/share/classes/com/sun/crypto/provider/HkdfKeyDerivation.java line 183:
> 
>> 181:             // perform expand
>> 182:             try {
>> 183:                 return Arrays.copyOf(hkdfExpand(pseudoRandomKey, info, length),
> 
> If the requested `length` happens to be multiples of `hmacLen`, then we can return the output of `hkdfExpand()` directly. No need for `Arrays.copyOf()`.

Since the desired length is passed into `hkdfExpand()` method, why not make `hkdfExpand()` return the output with the requested length?

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PR Review Comment: https://git.openjdk.org/jdk/pull/20301#discussion_r1735379148