native crypto node

import { Body, Controller, Get, Post } from '@nestjs/common';
import base64url from 'base64url';
import {
  arrayify,
  hashMessage,
  keccak256,
  recoverAddress,
  verifyMessage,
} from 'ethers/lib/utils';
import { connect, JSONCodec } from 'nats';

import * as crypto from 'crypto';

export class PublishMessageDto {
  fqcn: string;
  payload: string;
  signature: string;
}

var publicKey =
  '-----BEGIN PUBLIC KEY-----\n' +
  'MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDCtTEic76GBqUetJ1XXrrWZcxd\n' +
  '8vJr2raWRqBjbGpSzLqa3YLvVxVeK49iSlI+5uLX/2WFJdhKAWoqO+03oH4TDSup\n' +
  'olzZrwMFSylxGwR5jPmoNHDMS3nnzUkBtdr3NCfq1C34fQV0iUGdlPtJaiiTBQPM\n' +
  't4KUcQ1TaazB8TzhqwIDAQAB\n' +
  '-----END PUBLIC KEY-----';

@Controller()
export class AppController {
  connection = connect({ servers: 'nats://localhost:4222', debug: true });

  @Post()
  async postMessage(@Body() body: PublishMessageDto): Promise<void> {
    const c = await this.connection;
    const codec = JSONCodec();

    const res = this.verifyCrypto(body.signature, body, '0x0');
    console.log(res);

    c.publish(body.fqcn, codec.encode(body.payload));
  }

  private verifyCrypto(
    messageSignature: string,
    { fqcn, payload }: PublishMessageDto,
    user: string,
  ) {
    const verifier = crypto.createVerify('sha256');
    verifier.update(JSON.stringify({ fqcn, payload }));
    return verifier.verify(publicKey, messageSignature, 'hex');
  }

  private verifySignature(
    messageSignature: string,
    { fqcn, payload }: PublishMessageDto,
    user: string,
  ): boolean {
    const messageHash = hashMessage(JSON.stringify({ fqcn, payload }));
    const address = verifyMessage(messageHash, messageSignature);

    return address === user;
    // const [
    //   encodedHeader,
    //   encodedPayload,
    //   encodedSignature,
    // ] = messageSignature.split('.');

    // const msg = `0x${Buffer.from(`${encodedHeader}.${encodedPayload}`).toString(
    //   'hex',
    // )}`;
    // const hash = keccak256(msg);
    // const signature = base64url.decode(encodedSignature);
    // const addressFromHash = recoverAddress(arrayify(hash), signature);

    // if (user === addressFromHash) {
    //   return true;
    // }

    // const digest = hashMessage(arrayify(hash));
    // const addressFromDigest = recoverAddress(arrayify(digest), signature);
    // if (user === addressFromDigest) {
    //   return true;
    // }

    // return false;
  }
}