feat(api): Add Ed25519 sign/verify SubtleCrypto algo

[bsmth]

Summary

Currently the spec states:

Because the underlying cryptographic implementations will vary between conforming user agents... this specification does not dictate a mandatory set of algorithms that MUST be implemented. Instead, it defines a common set of bindings that can be used in an algorithm-independent manner...

There are a list of recommendations for implementers:

In order to promote interoperability for developers, this specification includes a list of suggested algorithms. These are considered to be the most widely used algorithms in practice at the time of writing, and therefore provide a good starting point for initial implementations of this specification. The suggested algorithms are:

HMAC using SHA-1
HMAC using SHA-256
RSASSA-PKCS1-v1_5 using SHA-1
RSA-PSS using SHA-256 and MGF1 with SHA-256.
RSA-OAEP using SHA-256 and MGF1 with SHA-256.
ECDSA using P-256 curve and SHA-256
AES-CBC

I've added a sub-feature for an algo which is not part of this recommendation, but is available in multiple engines.

Standardization status:

There's a WICG draft for Curve25519 and Curve448 in Web Crypto here

Test results and supporting details

• Chrome: 113 (behind flag)

  • Commit https://chromium-review.googlesource.com/c/chromium/src/+/4016576
  • Commit in find release tool: https://storage.googleapis.com/chromium-find-releases-static/2db.html#2db4c847d07e2811f9efff4387f20906d109dedf
  • Flag: enable-experimental-web-platform-features (chrome://flags/#enable-experimental-web-platform-features)

• Safari: Stable v17

  • Relnote https://webkit.org/blog/13839/release-notes-for-safari-technology-preview-163/
  • Commit WebKit/WebKit@3abe0e4

• Node.js: 16.17.0 (marked as experimental)

  • Docs - https://nodejs.org/dist/latest-v16.x/docs/api/webcrypto.html#ed25519ed448x25519x448-key-pairs
  • Changelog nodejs/node@5e5fb82

• Deno: 1.26.0

  • Changelog https://github.com/denoland/deno/blob/main/Releases.md#1260--20220928

• No Fx support

• WPT: generateKey

  • https://wpt.live/WebCryptoAPI/generateKey/successes_Ed25519.https.any.html
  • https://wpt.fyi/results/WebCryptoAPI/generateKey/successes_Ed25519.https.any.html?label=master&product=chrome%5Bexperimental%5D&product=deno%5Bexperimental%5D&product=firefox%5Bexperimental%5D&product=safari%5Bexperimental%5D&product=node.js%5Bexperimental%5D&product=chrome%5Bstable%5D&product=safari%5Bstable%5D&product=deno%5Bstable%5D&product=node.js%5Bstable%5D&aligned

Node repro:

async function generateAndSignKey() {
  const algorithm = { name: "Ed25519" };
  const encoder = new TextEncoder();
  const cryptoKey = await crypto.subtle.generateKey(
    algorithm,
    true,
    ["sign", "verify"]
  );

  console.log(
    await crypto.subtle.sign(
      algorithm,
      cryptoKey.privateKey,
      new Uint8Array([255])
    )
  );
}

generateAndSignKey();

output:

(node:27247) ExperimentalWarning: The Ed25519 Web Crypto API algorithm is an experimental feature and might change at any time
(Use `node --trace-warnings ...` to show where the warning was created)
ArrayBuffer {
  [Uint8Contents]: <bd 47 7d 05...
//
node --version
v20.11.0

Related issues

• Implementation status WICG/webcrypto-secure-curves#20
• SubtleCrypto: sign() method missing Ed25519 in Supported algorithms content#30886
• Add Ed25519 sign-verify example dom-examples#247

[guest271314]

Bun also supports Ed25519 algorithm via import { webcrypto } from "node:crypto".

[bsmth]

Bun also supports Ed25519 algorithm via import { webcrypto } from "node:crypto".

Bun is not (yet?) included in Browsers/Engines here. See #18484

[Elchi3]

Thanks @bsmth, some inline comments for you to look at. They apply to all for additions; I only commented on the first one.

[bsmth]

Thanks a lot, will take a look at your comments shortly 👍🏻

[Elchi3]

Thanks @bsmth, looks great to me! 👍

[bsmth]

Thank you! 🙏🏻