Implement X448, Ed448 when available in Botan

[TJ-91]

If MTG implements it, will use Botan 3.4 which works with RNP (avoiding the issues with current Botan head)

[TJ-91]

Now available: randombit/botan#3933

[ni4]

Just in case, we had plans on adding it to RNP anyway (believed we already had issue for this): rnpgp/rnp#2205

[falko-strenzke]

@ni4 So are you going to add it yourselves in any case? Otherwise we could also do it.

[ni4]

@falko-strenzke Yeah, I think it would be good to include it to the v0.18.0 release given that GnuPG already generates such keys. How soon do you need it to have?

[falko-strenzke]

@falko-strenzke Yeah, I think it would be good to include it to the v0.18.0 release given that GnuPG already generates such keys. How soon do you need it to have?

In the next 4 to 6 weeks would be good, since at some point we would need to create test vectors. But there is no fixed date for that.

[falko-strenzke]

@ni4
I wanted to ask in the meantime you have a timeline for the implementation of the 448 algorithms. We would need them for preparing a demo version of Thunderbird with the PQC with the 25519 and 448 Curve algorithms integrated. If it will be delayed on your side, we don't have a problem to implement it ourselves even if it would be parallel work.

[ni4]

@falko-strenzke I postponed it since started refactoring pgp_key_mateial_t to C++ classes, to not do the work twice. And then switched to CI issues which I'm on now. So if this needed very soon feel free to go ahead, I'll need at least some week or two to finish things I'm on now :(

[falko-strenzke]

We have started our own implementation now since we needed it now in our project for a delivery. It is in the branch https://github.com/pqc-thunderbird/rnp/tree/add-ed448-x448

@TJ-91 From our side we can close this ticket, right?

[TJ-91]

Yes, I'm closing it