Problem with public key loading

[misko-frame]

This is the code I am trying to run:

import eccrypto from 'eccrypto';

function removeLines(str: string): string {
  return str.replace('\n', '');
}

function base64ToArrayBuffer(b64: string): Uint8Array {
  const byteString = window.atob(b64);
  const byteArray = new Uint8Array(byteString.length);
  for (let i = 0; i < byteString.length; i++) {
    byteArray[i] = byteString.charCodeAt(i);
  }

  return byteArray;
}

function pemToArrayBuffer(pem: string): Uint8Array {
  const b64Lines = removeLines(pem);
  const b64Prefix = b64Lines.replace('-----BEGIN PUBLIC KEY-----', '');
  const b64Final = b64Prefix.replace('-----END PUBLIC KEY-----', '');

  return base64ToArrayBuffer(b64Final);
}

describe('test', () => {
  it('', async () => {
    const pk = '-----BEGIN PUBLIC KEY-----\n' +
      'MFYwEAYHKoZIzj0CAQYFK4EEAAoDQgAEW3yGReZI3dI37WZipbNcNunkHSX3gx5n\n' +
      'NFC8V5HyWtHktU17mDH+0zWDVodNazTqqQFIUIuXz/e++o1JFEYh2A==\n' +
      '-----END PUBLIC KEY-----';
    const publicKeyAsArrayBuffer = pemToArrayBuffer(pk);
    console.log('publicKeyAsArrayBuffer', publicKeyAsArrayBuffer);
    try {
      await eccrypto.encrypt(publicKeyAsArrayBuffer, Buffer.from('test', 'utf8'));
    } catch (e) {
      console.warn(e);
    }
  });
});

This code snippet is written as a unit test for sake of simplicity, the execution was also in the browser.
Basically, I am trying to transform pk pem to ArrayBuffer and encrypt a message, but getting Error: Bad public key
( btw public key in the example is legit)

Could someone suggest what needs to be done in order to be able to encrypt properly?

[willpiam]

did you get this to work?

[misko-frame]

nope... we have abandoned the approach with this lib

[jcbdev]

@misko-frame I don't support this library but I was just reading in passing whilst working on another project. If I convert the base64 to bytes manually from the example you posted above I get a buffer of 88 bytes.

ecdsa public keys are 64 bytes long. I think the issue might actually be the initial input?

I think the first 23 bytes is ASN.1 stuff as is mentioned here on this thread - https://security.stackexchange.com/questions/255644/how-do-i-turn-an-88-byte-ecdsa-public-key-into-a-65-byte-uncompressed-or-33-byte

i think you need to remove the first 23 bytes something like this:

let byteString = window.atob(b64);
byteString = byteString.substring(23, byteString.length);