hmac check seems to not work correctly in extension background contexts

[aulneau]

I've been playing around with using some of the noble libs in web extensions, specifically in the background context which is similar to service workers, and this line causes issues:

https://github.com/paulmillr/noble-hashes/blob/8b0fb5fb9485393df2896d380643a978de8714cf/src/hmac.ts#L17

When I console.log the iHash this is what we get:

{
    "blockLen": 64,
    "outputLen": 32,
    "padOffset": 8,
    "isLE": false,
    "finished": true,
    "length": 128,
    "pos": 0,
    "destroyed": false,
    "buffer": {
       // removed for brevity
    },
    "view": {},
    "A": 0,
    "B": 0,
    "C": 0,
    "D": 0,
    "E": 0,
    "F": 0,
    "G": 0,
    "H": 0
}

When I patch-package the hmac file and remove the conditional check, it works as expected.

Curious what we could do to make it work in this context? webcrypto should be fully supported

[paulmillr]

I don't see how background context is related to this line. Perhaps it's something else.

[aulneau]

oh yeah, sorry, the hashing i'm using is sha256:

import { ensureUint8Array } from './common';

import { hmac } from '@noble/hashes/hmac';
import { sha256 } from '@noble/hashes/sha256';

export function hmacSha256(key: Uint8Array, ...messages: Uint8Array[]): Uint8Array {
  const hash = hmac.create(sha256, ensureUint8Array(key));
  for (const message of messages) {
    hash.update(ensureUint8Array(message));
  }
  return Uint8Array.from(hash.digest());
}

so it might be the case that the sha256 class isn't correctly implementing the hash class you have defined on L17?

[paulmillr]

If it wasn't correct, the test wouldn't pass. I'm guessing it something else like some global variable not available in background context.

[paulmillr]

Do you know what is the simplest way to debug background page?

[xorgal]

Hey, I see that source was recently updated to:

if (typeof this.iHash.update !== 'function')

I'm having the same issue with previous equation if (!(this.iHash instanceof Hash)) and dependency that is relaying on @nobles/hashes is failing in production but works flawless with new comparison.

Would be great to update npm package with this change. Thanks!

[paulmillr]

landed in 1.1.3