RFR: 8325448: Hybrid Public Key Encryption [v46]

[Anthony Scarpino]

On Wed, 5 Nov 2025 18:27:51 GMT, Weijun Wang <weijun at openjdk.org> wrote:

>> Implement HPKE as defined in https://datatracker.ietf.org/doc/rfc9180/.
>> <img alt="image" src="https://github.com/user-attachments/assets/df3b454d-2161-4036-9930-c4f84d887b31" />
>
> Weijun Wang has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains 62 commits:
> 
>  - merge
>  - Merge branch 'master' into 8325448
>  - Tony's comment
>  - more key checks; some small spec change
>  - Merge branch 'master' into 8325448
>  - about transformation
>  - cannot reset with withMethods
>  - algorithm identifier
>  - withMethods
>  - duplicated "value" words
>  - ... and 52 more: https://git.openjdk.org/jdk/compare/cf45e09c...b5112151

src/java.base/share/classes/com/sun/crypto/provider/HPKE.java line 137:

> 135:             throws InvalidKeyException, InvalidAlgorithmParameterException {
> 136:         impl = new Impl(opmode);
> 137:         if (!(key instanceof AsymmetricKey ak)) {

Is a null check needed for `key` and `params`?  It appears Cipher leaves that to the SPI to accept or reject.

src/java.base/share/classes/com/sun/crypto/provider/HPKE.java line 318:

> 316:             }
> 317: 
> 318:             SecretKey ExportKey(String algorithm, byte[] exporter_context, int L) {

Why are the methods in this class capitalized?

src/java.base/share/classes/com/sun/crypto/provider/HPKE.java line 540:

> 538:                 // thw builder are just byte arrays. Any KDF impl can handle this.
> 539:                 var kdf = KDF.getInstance(kdfAlg);
> 540:                 var key_schedule_context = concat(new byte[]{(byte) mode},

Is `key_sechedule_context` worth zero'ing?

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PR Review Comment: https://git.openjdk.org/jdk/pull/18411#discussion_r2495870196
PR Review Comment: https://git.openjdk.org/jdk/pull/18411#discussion_r2496532422
PR Review Comment: https://git.openjdk.org/jdk/pull/18411#discussion_r2496764265