Support for Ed(X)25519

[olegbespalov]

What?

Even though original WebCrypto API doesn't include support of the Curve25519, but many of webcrypto implementation does w3c/webcrypto#362

Even WebPlatfrom test suit tests this support, which led us to patch https://github.com/grafana/xk6-webcrypto/blob/main/webcrypto/tests/wpt-patches/WebCryptoAPI__generateKey__failures.js.patch

Draft can be found https://wicg.github.io/webcrypto-secure-curves/

From the Golang's perspective, support also looks good since we have packages:

• https://pkg.go.dev/crypto/[email protected]
• https://pkg.go.dev/golang.org/x/[email protected]/curve25519

Why?

Seems like support of this Curve25519 is demanded, so having it in k6 makes k6's implementation more attractive and useful for customers.