ext/sodium: Add crypto_kem (X-Wing) and crypto_kem_mlkem768 bindings

[ZacharyDuBois]

libsodium 1.0.22 introduced a KEM API: X-Wing (hybrid ML-KEM768+X25519, upstream's recommended KEM) and ML-KEM768 (FIPS 203). This exposes both:

• sodium_crypto_kem_{keypair,seed_keypair,secretkey,publickey,enc,dec}
• sodium_crypto_kem_mlkem768_{keypair,seed_keypair,secretkey,publickey,enc,dec} + SODIUM_CRYPTO_KEM[_MLKEM768]_*BYTES constants

[ZacharyDuBois]

Tried sending an email to internals but seems like y'all don't support DMARC with p=reject as it just bounced as the mailing list seems to be changing my DKIM signature.

[NickSdot]

Tried sending an email to internals but seems like y'all don't support DMARC with p=reject as it just bounced as the mailing list seems to be changing my DKIM signature.

While the subscribe step? If yes, you maybe want to ping @ derickr.

[ZacharyDuBois]

But you did the subscribe step? If yes, you maybe want to ping @ derickr.

Yep, sent an intro (I think on Thursday) and that went though but shortly after I got the forensic report and it showed both SPF and DKIM failed. Looking at the headers, looks like it hit a relay causing the failure. Running an outbound test reports my email is all good.

[NickSdot]

But you did the subscribe step? If yes, you maybe want to ping @ derickr.

Yep, sent an intro (I think on Thursday) and that went though but shortly after I got the forensic report and it showed both SPF and DKIM failed. Looking at the headers, looks like it hit a relay causing the failure. Running an outbound test reports my email is all good.

Fwiw, it went through anyway: https://news-web.php.net/php.internals/132308

[jedisct1]

The changes look good to me.

Thanks a lot for adding these functions!

[ZacharyDuBois]

@jedisct1 no problem! I have a project I am working on that needed some post-quantum stuff added in (more so for playing around). Saw these were missing and didn't feel like hassling someone to add them when I am perfectly capable of it.

This is my first PR for PHP so let me know if I am missing anything! More than happy to make any edits. From what I heard on the mailing list, 8.6 is on a feature freeze so sadly it sounds like this won't make it out for 8.6 :(

[ZacharyDuBois]

Fixed the merge conflict with NEWS

[Girgias]

Probably best for @paragonie-scott / @paragonie-security to review this. :)

[ZacharyDuBois]

@Girgias more the merrier but this is only direct passthrough to libsodium which is maintained by @jedisct1 with a bit of conversion to make it PHP-esque. That and a bunch of tests that are similar to the ones in place for the other libsodium calls.

[Girgias]

@Girgias more the merrier but this is only direct passthrough to libsodium which is maintained by @jedisct1 with a bit of conversion to make it PHP-esque. That and a bunch of tests that are similar to the ones in place for the other libsodium calls.

He does maintain https://github.com/jedisct1/libsodium-php so his input would probably be useful too :)