X-Hub-Signature does not match blob signature

using my own function works but it crash with github-webhook-handler:

    const createComparisonSignature = (body) => {
      const hmac = crypto.createHmac('sha1', process.env.GITHUB_SECRET);
      const self_signature = hmac.update(JSON.stringify(body)).digest('hex');
      return `sha1=${self_signature}`; // shape in GitHub header
    }
    const compareSignatures = (signature, comparison_signature) => {
      const source = Buffer.from(signature);
      const comparison = Buffer.from(comparison_signature);
      return crypto.timingSafeEqual(source, comparison); // constant time comparison
    }
    const { headers, body } = req;
    const signature = headers['x-hub-signature'];
    const comparison_signature = createComparisonSignature(req.body);
    if (!compareSignatures(signature, comparison_signature)) {
      return res.status(401).send('Mismatched signatures');
    } else {
      console.log("signature match")
      const { action, ...payload } = body;
      req.event_type = headers['x-github-event']; // one of: https://developer.github.com/v3/activity/events/types/ 
      req.action = action;
      req.payload = payload;
      next();
    }
    return next()

please let me know if there is any solution

issue ではソースファイルもテストも指定されていません。まず github-webhook-handler が req.body をどのように受け取り、解析しているかを追跡し、次に署名検証に使用されるバイト列を元のリクエストボディと比較してください。報告された不一致がなく、有効な X-Hub-Signature が一貫して検証できれば完了です。