validate whatsapp sha 256

validateWhatsAppSha256.ts

const signature = ctx.request.headers['x-hub-signature-256'];

  if (
    !signature ||
    typeof signature !== 'string' ||
    !config.WHATSAPP_APP_SECRET
  ) {
    ctx.status = 403;
    ctx.body = {
      message: 'invalid signature',
    }

    return;
  }

  const sha256 = signature.split('=')[1];

  // eslint-disable-next-line no-restricted-syntax
  const result = crypto
    .createHmac('sha256', config.WHATSAPP_APP_SECRET)
    .update(ctx.request.rawBody)
    .digest('hex');

  if (!sha256 || sha256 !== result) {
    ctx.status = 403;
    ctx.body = {
      message: 'invalid signature',
    }

    return;
  }