RFR: 8331008: Implement JEP 478: Key Derivation Function API (Preview) [v56]

[Valerie Peng]

On Fri, 11 Oct 2024 17:57:18 GMT, Kevin Driver <kdriver at openjdk.org> wrote:

>> Introduce an API for Key Derivation Functions (KDFs), which are cryptographic algorithms for deriving additional keys from a secret key and other data. See [JEP 478](https://openjdk.org/jeps/478).
>> 
>> Work was begun in [another PR](https://github.com/openjdk/jdk/pull/18924).
>
> Kevin Driver has updated the pull request incrementally with one additional commit since the last revision:
> 
>   enable debug flag for exhaustive test @run

test/jdk/com/sun/crypto/provider/KDF/HKDFKnownAnswerTests.java line 65:

> 63:             // Non-mandatory fields - may be null
> 64:             salt = (saltStr != null) ? HexFormat.of().parseHex(saltStr) : null;
> 65:             info = (infoStr != null) ? HexFormat.of().parseHex(infoStr) : null;

Instead of `null`, you should use new byte[0] for the default value when the corresponding string value is `null`. Because the `addSalt()` is always invoked regardless of the salt value.

test/jdk/com/sun/crypto/provider/KDF/HKDFKnownAnswerTests.java line 113:

> 111:         add(new TestData("RFC 5869 Test Case 3", "HKDF-SHA256",
> 112:                          "0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b",
> 113:                          new String(new byte[0]), new String(new byte[0]), 42,

Instead of `new String(new byte[0])`, you should be able to just use `null` for optional arguments?

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PR Review Comment: https://git.openjdk.org/jdk/pull/20301#discussion_r1800177530
PR Review Comment: https://git.openjdk.org/jdk/pull/20301#discussion_r1800178544