RFR: 8331008: Implement JEP 478: Key Derivation Function API (Preview) [v43]

[Kevin Driver]

On Wed, 18 Sep 2024 21:49:14 GMT, Valerie Peng <valeriep at openjdk.org> wrote:

>> src/java.base/share/classes/com/sun/crypto/provider/HKDFKeyDerivation.java line 92:
>> 
>>> 90:         }
>>> 91:         this.hmacAlgName = hmacAlgName;
>>> 92:         this.hmacLen = hmacLen;
>> 
>> Instead of doing a binary search whenever an HKDFKeyDerivation object is constructed, it is better to organize the algorithm and output length into an enum, this way, supporting new Hmac algorithms would require adding new enum value. This should be sufficient since these arguments are internally supplied. For example,
>> 
>> public enum SupportedHmac {
>>         SHA256("HmacSHA256", 32),
>>         SHA384("HmacSHA384", 48),
>>         SHA512("HmacSHA512", 64);
>> 
>>         public final String algo;
>>         public final int outLen;
>>         private SupportedHmac(String algo, int outLen) {
>>             this.algo = algo;
>>             this.outLen = outLen;
>>         }
>>  };
>
> Then the constructor can specify enum as the argument, e.g. 
> 
>     private HKDFKeyDerivation(SupportedHmac h,
>                               KDFParameters kdfParameters)
>             throws InvalidAlgorithmParameterException {
>         super(kdfParameters);
>         if (kdfParameters != null) {
>             throw new InvalidAlgorithmParameterException(
>                     h.algo + " does not support parameters");
>         }
>         this.hmacAlgName = h.algo;
>         this.hmacLen = h.outLen;
>     }

Addressed in https://github.com/openjdk/jdk/pull/20301/commits/f786a38179651a5bca8c4884eeb52d2cef0adc78.

>> src/java.base/share/classes/com/sun/crypto/provider/HKDFKeyDerivation.java line 396:
>> 
>>> 394:         public HKDFSHA256(KDFParameters kdfParameters)
>>> 395:                 throws InvalidAlgorithmParameterException {
>>> 396:             super("HmacSHA256", SHA256_HMAC_SIZE, kdfParameters);
>> 
>> Using the enum, this line would be:
>> `            super(SupportedHmac.SHA256, kdfParameters);`
>
> Similar changes to the other child classes below.

Addressed in https://github.com/openjdk/jdk/pull/20301/commits/f786a38179651a5bca8c4884eeb52d2cef0adc78.

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

PR Review Comment: https://git.openjdk.org/jdk/pull/20301#discussion_r1769194465
PR Review Comment: https://git.openjdk.org/jdk/pull/20301#discussion_r1769194017