Accepting CryptoKey in node:crypto APIs

[panva]

The following APIs accept a CryptoKey instance and process the operation despite the restrictions put forth on the CryptoKey instance (e.g. algorithm, usages, extractable)

• KeyObject.from (ignores extractable)
• crypto.publicDecrypt
• crypto.publicEncrypt
• crypto.privateDecrypt
• crypto.privateEncrypt
• crypto.sign
• crypto.verify
• Sign.sign
• Verify.verify
• Cipher.final
• Decipher.final
• Hmac.digest

This list is according to the docs, but i suspect it's possible that hkdf and pbkdf2 allow this too.

This issue is to discuss a way forward to deal with this issues.

KeyObject.from

#37240 attempted to do something about KeyObject.from but i think the outcome would not solve the issues above.

I believe that converting key representations is not an issue so long as the more restrictive key representation's properties are upheld.

We can take a drastic stance and deprecate / in due time remove KeyObject.from entirely, or make KeyObject.from respect the extractable property and duly document that once the key is converted the CryptoKey restrictions are not upheld anymore. I'd much rather see the latter.

Another possible approach would be to disable KeyObject.export on keys that came from non-extractable CryptoKey.

APIs accepting CryptoKey but ignoring its parameters.

We could deprecate the use of CryptoKey in these APIs entirely or emulate WebCryptoAPI behaviour and check the CryptoKey usages and algorithm slots, either way this would be a doc-only deprecation at first, then --pending-deprecation, runtime deprecation, throw behaviour at the end.

[panva]

cc @nodejs/crypto

[panva]

My preferred state is to have a way to convert KeyObject <> CryptoKey both ways (KeyObject.from (while respecting extractable) and #55262) but not have node:crypto APIs accept CryptoKey and not have SubtleCrypto accept KeyObject (already not possible).

This is even with my jose author/maintainer hat on. I don't make use of CryptoKey in node:crypto APIs. I do make use of KeyObject.from, but before KeyObject.from conversion I do check the CryptoKey properties and the resulting KeyObject is never returned to the user.