I believe I got it working. Since my PR now relies on [1] your key encoding changes, shall I push the changes or rather wait until your’s is merged into master?
[1]: https://github.com/openjdk/jdk/pull/24969 > On 3. Aug 2025, at 21:56, Wei-Jun Wang <weijun.w...@oracle.com> wrote: > > The ML-KEM key does not need to be serialized anywhere so I think its > encoding does not matter. If you already have the expanded key you can > directly create a NamedPKCS8Key whose expander is an identity function, i.e. > both its encoding and expanded key are the expanded key itself. The encoding > does not necessarily be the seed. > > Thanks, > Weijun > >> On Aug 2, 2025, at 13:42, Sebastian Stenzel <sebastian.sten...@gmail.com> >> wrote: >> >> Hi, >> >> I merged your NamedPKCS8Key branch into the X-Wing branch and tried to >> adjust to the new API. I encountered one problem: >> >> With your changes, `NamedKEM#implDecapsulate` will now receive the expanded >> key (no longer the raw seed). So far, so good. However, in X-Wing I need to >> split this into an ML-KEM key and the X25519 key. Now here is the problem: >> If I only have expanded bytes, how can I construct an ML-KEM key? >> NamedPKCS8Key requires „raw key bytes, not null“ (i.e. the seed) and only >> optionally the expanded bytes. >> >> Is there any internal API I can use to run ML-KEM’s decapsulate with a >> byte[] key? >> >> Otherwise, I would suggest that you widen the signature of >> `NamedKEM#implDecapsulate` to receive both parameters, the seed and the >> expanded key. >> >> Cheers, >> Sebastian >> >>> On 23. Jul 2025, at 17:52, Wei-Jun Wang <weijun.w...@oracle.com> wrote: >>> >>> >>> >>>> On Jul 23, 2025, at 11:41, Sebastian Stenzel <sebastian.sten...@gmail.com> >>>> wrote: >>>> >>>> Welcome back, I hope you enjoyed the time! :-) >>>> >>>> If you find time, can you give me an update on the ASN.1 key encoding >>>> topic? This is the only remaining issue to fulfill the spec. Afterwards we >>>> simply need to wait for the final test vectors and publication of the RFC. >>> >>> https://github.com/openjdk/jdk/pull/24969 updated NamedPKCS8Key which >>> contains both the encoding format (as in PKCS #8) and the expanded format >>> (used in calculation). For X-Wing, I think the encoding will be the seed, >>> but you are free to choose the expanded format, or, you can "expand" it to >>> an arbitrary object at NamdKEM::implCheckPrivateKey. The KeyPairGenerator >>> interface does not have a deterministic generateKey method so you will have >>> to call internal methods for both ML-KEM and x25519. >>> >>> Thanks, >>> Weijun >>> >>>> >>>> Thank you! >>>> Sebastian >>>> >>>>> Am 23.07.2025 um 14:33 schrieb Wei-Jun Wang <weijun.w...@oracle.com>: >>>>> >>>>> Hi Sebastian, >>>>> >>>>> I'm back from my vacation. Thanks for the update. >>>>> >>>>> I agree, using NamedKey is probably a better choice anyway. It's nice >>>>> that getParams() always return a name and we don't need to call >>>>> getAlgorithm() as a fallback. >>>>> >>>>> Thanks, >>>>> Weijun >>>>> >>>>>> On Jun 30, 2025, at 06:06, Sebastian Stenzel >>>>>> <sebastian.sten...@gmail.com> wrote: >>>>>> >>>>>> Quoting Bas Westerbaan (in CC) again, we will most likely see further >>>>>> PQ/T hybrids from the IETF crypto forum research group (CFRG for short): >>>>>> >>>>>>> It seems likely that the CFRG will at some point produce a >>>>>>> P-384+ML-KEM-1024 hybrid. See >>>>>>> https://mailarchive.ietf.org/arch/msg/cfrg/CwrVvm-J7o85TEWkG9RJxZwfXDY/ >>>>>>> . That might take some time. >>>>>>> >>>>>>> Very few (but notably Ericsson) have asked for X448 hybrids, so I don't >>>>>>> expect them soon. >>>>>> >>>>>> That said, the construction does not necessarily be compatible to >>>>>> X-Wing. Just to be sure, I asked whether they see any value in >>>>>> parameterizing X-Wing to swap out algorithms. This is what Bas replied: >>>>>> >>>>>>> Even if the other hybrids will also use an X-Wing style combiner, it >>>>>>> doesn't hurt not to parametrize initially. :) >>>>>> >>>>>> So I would suggest to follow this advice for now and only refactor the >>>>>> implementation eventually, when further pairs of algorithms are combined >>>>>> in the same way. >>>>>> >>>>>> Best, >>>>>> Sebastian >>>>>> >>>>>> >>>>>>>> On 29. Jun 2025, at 12:02, Sebastian Stenzel >>>>>>>> <sebastian.sten...@gmail.com> wrote: >>>>>>> >>>>>>> >>>>>>>> On 28. Jun 2025, at 00:12, Wei-Jun Wang <weijun.w...@oracle.com> wrote: >>>>>>>> >>>>>>>> [...] After all, there is no parameter for X-Wing. Did you hear the >>>>>>>> authors they want to introduce other algorithms like ed448 and >>>>>>>> ML-KEM-1024 into it? >>>>>>> >>>>>>> I forwarded this question and let you know the answer! >>>>>>> >>>>>>> >>>>>>>>> >>>>>>>>>> On 7. Jun 2025, at 23:34, Wei-Jun Wang <weijun.w...@oracle.com> >>>>>>>>>> wrote: >>>>>>>>>> >>>>>>>>>> Cool. >>>>>>>>>> >>>>>>>>>> The current NamedPKCS8Key was designed based on an older approach >>>>>>>>>> where modern asymmetric keys store private key data in a nested >>>>>>>>>> OCTET STRING format. This pattern was introduced with EdDSA and XDH, >>>>>>>>>> and at the time of JDK 24, we anticipated it would become the norm. >>>>>>>>>> >>>>>>>>>> However, things have changed significantly, as seen in the evolution >>>>>>>>>> of draft-ietf-lamps-dilithium-certificates and >>>>>>>>>> draft-ietf-lamps-kyber-certificates. The original design now needs >>>>>>>>>> to be revised. While we’re still waiting for the IETF drafts to be >>>>>>>>>> finalized, we’re already experimenting with changes in >>>>>>>>>> https://github.com/openjdk/jdk/pull/24969. >>>>>>>>>> >>>>>>>>>> Hopefully, by the time X-Wing is finalized, we’ll already have a >>>>>>>>>> solution in place. >>>>>>>>>> >>>>>>>>>> Thanks, >>>>>>>>>> Weijun >>>>>>>>>> >>>>>>>>>>> On Jun 7, 2025, at 16:14, Sebastian Stenzel >>>>>>>>>>> <sebastian.sten...@gmail.com> wrote: >>>>>>>>>>> >>>>>>>>>>> Hi Weijun, >>>>>>>>>>> >>>>>>>>>>> I got a mostly working implementation based on NamedKEM [0], >>>>>>>>>>> however to fulfil the spec I need your advice: >>>>>>>>>>> >>>>>>>>>>> The (current) X-Wing spec wants this PKCS#8 encoding: [1] >>>>>>>>>>> >>>>>>>>>>> However, the NamedPKCS8Key implementation always puts a nested >>>>>>>>>>> OctetString into the private key part. [2] >>>>>>>>>>> >>>>>>>>>>> Note the difference here: >>>>>>>>>>> * >>>>>>>>>>> https://lapo.it/asn1js/#MDQCAQAwDQYLKwYBBAGD5i2ByHoEIAABAgMEBQYHCAkKCwwNDg8QERITFBUWFxgZGhscHR4f >>>>>>>>>>> * >>>>>>>>>>> https://lapo.it/asn1js/#MDYCAQAwDQYLKwYBBAGD5i2ByHoEIgQg9IFQEyQtdLJL8j-hRm6Yzx3CzFiDyNk4yCADl6ZiXWo >>>>>>>>>>> >>>>>>>>>>> I believe we need some more flexibility, as the ASN.1 standard >>>>>>>>>>> leaves it open to the algorithms how a private key is formatted. >>>>>>>>>>> What do you think how to approach this? >>>>>>>>>>> >>>>>>>>>>> Or should I ask the authors whether they have a specific encoding >>>>>>>>>>> in mind? The ASN.1 definitions in the spec don’t seem to be >>>>>>>>>>> complete yet. >>>>>>>>>>> >>>>>>>>>>> Best regards, >>>>>>>>>>> Sebastian >>>>>>>>>>> >>>>>>>>>>> [0]: >>>>>>>>>>> https://github.com/openjdk/jdk/compare/master...overheadhunter:jdk:x-wing >>>>>>>>>>> [1]: >>>>>>>>>>> https://www.ietf.org/archive/id/draft-connolly-cfrg-xwing-kem-07.html#appendix-D >>>>>>>>>>> [2]: >>>>>>>>>>> https://github.com/openjdk/jdk/blob/d7352559195b9e052c3eb24d773c0d6c10dc23ad/src/java.base/share/classes/sun/security/pkcs/NamedPKCS8Key.java#L76-L81 >>>>>>>>>>> >>>>>>>>>>>> On 30. May 2025, at 15:03, Wei-Jun Wang <weijun.w...@oracle.com> >>>>>>>>>>>> wrote: >>>>>>>>>>>> >>>>>>>>>>>> >>>>>>>>>>>> >>>>>>>>>>>>> On May 30, 2025, at 08:40, Sebastian Stenzel >>>>>>>>>>>>> <sebastian.sten...@gmail.com> wrote: >>>>>>>>>>>>> >>>>>>>>>>>>> Hi Weijun, >>>>>>>>>>>>> >>>>>>>>>>>>> waiting for the final standard is understandable. The internals >>>>>>>>>>>>> may still change, but the „outer hull“ of the PR is something >>>>>>>>>>>>> that could already be discussed before - under these premises, >>>>>>>>>>>>> would it make sense to already start a draft? Knowing that it >>>>>>>>>>>>> won’t be merged yet? >>>>>>>>>>>> >>>>>>>>>>>> Feel free to start a draft if you’d like. I'll create a JBS issue >>>>>>>>>>>> once we decide we want to include it in the JDK. >>>>>>>>>>>> >>>>>>>>>>>>> >>>>>>>>>>>>> I have a working set of KeyPairGenerator, KeyFactory and KEM SPI >>>>>>>>>>>>> including test vectors basically ready - just SHAKE256 currently >>>>>>>>>>>>> borrowed from BC. >>>>>>>>>>>>> >>>>>>>>>>>>> I know that using SHAKE256 within the JDK is not a problem. >>>>>>>>>>>>> However if we want to make it public, there simply *is no* XOF >>>>>>>>>>>>> API in JCA. Technically the expand step of the KDF API can be >>>>>>>>>>>>> used, but semantically that would be a misuse. Adding a >>>>>>>>>>>>> completely new API is nothing I currently want to work on. >>>>>>>>>>>> >>>>>>>>>>>> I see. >>>>>>>>>>>> >>>>>>>>>>>>> >>>>>>>>>>>>> Btw I am somewhat familiar with the development process as I have >>>>>>>>>>>>> started contributing to the JDK in 2021 on cipher and NIO issues. >>>>>>>>>>>>> [1] >>>>>>>>>>>> >>>>>>>>>>>> Nice to know. Sorry I didn't noticed that earlier. >>>>>>>>>>>> >>>>>>>>>>>> Thanks, >>>>>>>>>>>> Weijun >>>>>>>>>>>> >>>>>>>>>>>>> >>>>>>>>>>>>> Thank you, >>>>>>>>>>>>> Sebastian >>>>>>>>>>>>> >>>>>>>>>>>>> [1] >>>>>>>>>>>>> https://github.com/openjdk/jdk/pulls?q=is%3Apr+author%3Aoverheadhunter >>>>>>>>>>>>> >>>>>>>>>>>>>> On 29. May 2025, at 18:44, Wei-Jun Wang <weijun.w...@oracle.com> >>>>>>>>>>>>>> wrote: >>>>>>>>>>>>>> >>>>>>>>>>>>>> Hi Sebastian. >>>>>>>>>>>>>> >>>>>>>>>>>>>>> On May 24, 2025, at 05:40, Sebastian Stenzel >>>>>>>>>>>>>>> <sebastian.sten...@gmail.com> wrote: >>>>>>>>>>>>>>> >>>>>>>>>>>>>>> Hi all, >>>>>>>>>>>>>>> >>>>>>>>>>>>>>> For the past few months I have been in contact with one of the >>>>>>>>>>>>>>> authors of two spec drafts for future JOSE encryption standards >>>>>>>>>>>>>>> [1] [2] with the latter of them relying on X-Wing. >>>>>>>>>>>>>>> >>>>>>>>>>>>>>> As the X-Wing spec doesn’t face significant changes any more >>>>>>>>>>>>>>> (there have been some larger shifts in regards to secret key >>>>>>>>>>>>>>> derivation last year), I am now tasked to create a prototype >>>>>>>>>>>>>>> implementation for these RFCs. >>>>>>>>>>>>>> >>>>>>>>>>>>>> Thanks for your continued interest on enhancing OpenJDK. >>>>>>>>>>>>>> >>>>>>>>>>>>>> That said, we have a policy of not implementing algorithms that >>>>>>>>>>>>>> haven't been standardized. So we won't be able to consider your >>>>>>>>>>>>>> contribution until IETF publishes draft-connolly-cfrg-xwing-kem >>>>>>>>>>>>>> as an RFC. I'm not sure how familiar you are with the OpenJDK >>>>>>>>>>>>>> developing process, but in the meantime, you might find it >>>>>>>>>>>>>> helpful to read the OpenJDK Developers’ Guide [1] and try >>>>>>>>>>>>>> working on something smaller first. >>>>>>>>>>>>>> >>>>>>>>>>>>>>> >>>>>>>>>>>>>>> All the primitives for X-Wing are technically already there in >>>>>>>>>>>>>>> OpenJDK, however two of them are private API (namely SHAKE256 >>>>>>>>>>>>>>> and ML-KEM’s `KeyGen_internal(d, z)` [3]). So the question >>>>>>>>>>>>>>> arises whether I can contribute an X-Wing KEM implementation to >>>>>>>>>>>>>>> the JDK at the current state of the spec? >>>>>>>>>>>>>> >>>>>>>>>>>>>> It's acceptable to use private API inside OpenJDK when you are >>>>>>>>>>>>>> working on OpenJDK itself. After all, we created them for this >>>>>>>>>>>>>> very purpose. However, please keep in mind that this means you >>>>>>>>>>>>>> bind your X-Wing implementation to the SunJCE/SunEC >>>>>>>>>>>>>> implementations. Usually, as a higher-level algorithm, if its >>>>>>>>>>>>>> underlying algorithms could be implemented by different security >>>>>>>>>>>>>> providers, it will be nice to make it provider-neutral where >>>>>>>>>>>>>> possible. >>>>>>>>>>>>>> >>>>>>>>>>>>>>> >>>>>>>>>>>>>>> Alternatively, can we make the two mentioned APIs public? >>>>>>>>>>>>>> >>>>>>>>>>>>>> No. These methods are too specific to their respective >>>>>>>>>>>>>> algorithms. We prefer JCA/JCE-style API that is >>>>>>>>>>>>>> algorithm-neutral. >>>>>>>>>>>>>> >>>>>>>>>>>>>> [1] https://openjdk.org/guide/ >>>>>>>>>>>>>> >>>>>>>>>>>>>> Thanks, >>>>>>>>>>>>>> Weijun >>>>>>>>>>>>>> >>>>>>>>>>>>>>> >>>>>>>>>>>>>>> Cheers! >>>>>>>>>>>>>>> Sebastian >>>>>>>>>>>>>>> >>>>>>>>>>>>>>> [1]: >>>>>>>>>>>>>>> https://datatracker.ietf.org/doc/html/draft-ietf-jose-hpke-encrypt/ >>>>>>>>>>>>>>> [2]: >>>>>>>>>>>>>>> https://datatracker.ietf.org/doc/html/draft-reddy-cose-jose-pqc-hybrid-hpke-07 >>>>>>>>>>>>>>> [3]: >>>>>>>>>>>>>>> https://github.com/openjdk/jdk/blob/070c84cd22485a93a562a7639439fb056e840861/src/java.base/share/classes/com/sun/crypto/provider/ML_KEM.java#L498-L536 >>>>>>>>>>>>>>> >>>>>>>>>>>>>> >>>>>>>>>>>>> >>>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>> >>>>>>>>> >>>>>>>> >>>>>>> >>>>>> >>>>> >>> >> >
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