code: function(callback) {
          if (authHeader.length === 0) {
            callback('missing header');
          } else {
            res.parsedHeader = Header.parse(authHeader, my.config.key, my.config.cert);
            senderCert = res.parsedHeader.payload.cert;  // get the certificate in handshake
            reqSid = res.parsedHeader.payload.sid;
            reqToken = res.parsedHeader.content.token;
            callback(null);
          }
        }
docs: parse header