Proposal: Add Ed25519 and Curve25519 Algorithms to System.Security.Cryptography

[janhenke]

The System.Security.Cryptography namespace contains several commonly used cryptographic algorithms. I propose the addition of two commonly used algorithms which are currently missing:

• Ed25519 is an implementation of an Edwards-curve Digital Signature Algorithm.
• Curve25519 is an algorithm designed to be used with elliptic curve Diffie-Hellman (ECDH) key exchange algorithm.

Both are based on the same elliptic curve. Many open source projects (e.g. OpenSSH, OpenBSD) seem to prefer this elliptic curve for use in elliptic curve cryptography (ECC). It is therefore beneficial to have these algorithms implemented in CoreFX.

The two algorithms should be included in the existing classes in the System.Security.Cryptography namespace, but it must be possible to explicitly ask for the usage of these algorithms.

[saper]

Definitely a good idea.

Daniel J. Bernstein "Can anything do better than elliptic curves?"

Daniel J. Bernstein papers on Curve25519

[ellismg]

/cc @sandkum, @bartonjs, @nguerrera

[guardrex]

Is asking for SHA256Cng for dnxcore50 related? ... mean in the sense of keeping community requests for expanded System.Security.Cryptography in the same issue, or should I ask in a separate issue? It's probably going to be needed for ADAL (source1, source2).

[ellismg]

I would prefer if you open another issue. Thanks!

[bartonjs]

@guardrex That'd be a separate issue 😄.

[janhenke]

Is this issue being worked on? Is any further information necessary?

[bartonjs]

The good news is that no further information is necessary 😄. The bad news is that we're currently focused on getting cross-platform support caught up to the existing API, so no one is working on this currently.

Once we have cross-plat caught up, then we'll move on to new functionality in lockstep; and the first "new" thing that I can think of would be to start pulling over the elliptic curve types from the full framework (which, since we're borrowing code from full framework, isn't really new 😄). And once that's done this becomes actionable.

So, hopefully that makes sense... it's definitely on the radar, but not quite yet on the schedule.

[janhenke]

Okay, I hope we can finish FreeBSD support in CoreFX soon then. I was just asking to make sure this topic is not forgotten.

[bartonjs]

Curve25519 should be usable once dotnet/corefx#8158 is completed (since it's an ECDH-only curve); but since it doesn't have a registered OID it isn't a first-class citizen. (It should work on Windows via a named curve using new Oid(null, "curve25519") since Windows does by-name lookup; but OpenSSL does by-value lookup and therefore can't discover it).

Ed25519 being a completely different algorithm will require more/unique work.

[karelz]

We need API proposal for each algorithm.
Keep in mind that each new algorithm has to receive Microsoft crypto-board approval - we can help get it started, but there is no guarantee about the result.

[andymac4182]

Is there any movement on this? Found a good looking library but it requires Span so waiting for that https://github.com/ektrah/nsec