Jose 6.x does not work in Cloudflare Worker

[tripodsan]

What happened?

Exporting a key in a cloudflare worker causes problems with the CF provided crypto classes:

TypeError: Key must be one of type CryptoKey, KeyObject, or Uint8Array. Received an instance of CryptoKey
    at keyToJWK (index.js:97:11)
    at exportJWK (index.js:107:10)
    at Object.handleRequest [as fetch] (index.js:204:29)

(see example below)

the problem seems to be this check:

function isCryptoKey(key) {
  return key?.[Symbol.toStringTag] === "CryptoKey";
}

this returns CryptoKey in NodeJS, but undefined in the worker.
I think this is mainly problem of the provided crypto library of cloudflare.

maybe this can be improved to also check actual.constructor?.name ?

for example:

function isCryptoKey(key) {
  return (key?.[Symbol.toStringTag] ?? key.constructor?.name) === "CryptoKey";
}

Version

6.0.8

Runtime

Cloudflare Workers

Runtime Details

compatibility 2024-03-21

Code to reproduce

import { exportJWK, generateKeyPair } from 'jose';

const handleRequest = async (req, env/* , ctx */) => {
  try {
    const keyPair = await generateKeyPair('RS256', { extractable: true });
    const publicKey = await exportJWK(keyPair.publicKey);

    return new Response(publicKey, {
      status: 200,
    });
  } catch (err) {
    console.error(err);
    return new Response(err.stack, { status: 500 });
  }
};

export default {
  fetch: handleRequest,
};

Required

• I have searched the issues tracker and discussions for similar topics and couldn't find anything related.
• I agree to follow this project's Code of Conduct

[tripodsan]

i just realized that setting the worker compatibility to the latest 2024-11-11 solves the issue.

[tripodsan]

for completeness, the second recent compatibility version still showed this issue, so CF just fixed this recently:

compatibility_date = "2024-09-02":

[
"Public Key Test",
"key type: \"undefined\"",
"constructor: \"CryptoKey\"",
"error",
"TypeError: Key must be one of type CryptoKey, KeyObject, or Uint8Array. Received an instance of CryptoKey\n    at keyToJWK (index.js:97:11)\n    at exportJWK (index.js:107:10)\n    at Object.handleRequest [as fetch] (index.js:207:29)"
]

[panva]

Yup, cloudflare/workerd#2769

[panva]

Also https://github.com/panva/jose/actions/runs/13496783369/job/37705823981

[panva]

FYI: https://github.com/panva/jose/releases/tag/v6.1.2