code: function createClientDHInnerData(context) {
      var retryCount = 0;
      if (logger.isDebugEnabled()) {
          logger.debug('Start calculating g_b');
      }
      // Calculate g_b
      var g = context.serverDHInnerData.g;
      var b = utility.createNonce(256);
      var dhPrime = context.serverDHInnerData.dh_prime;
      var gb = utility.modPow(g, b, dhPrime);
      if (logger.isDebugEnabled()) {
          logger.debug('g_b(%s) = %s', gb.length, gb.toString('hex'));
      }
      // Create client DH inner data
      context.clientDHInnerData = new mtproto.type.Client_DH_inner_data({
          props: {
              nonce: context.resPQ.nonce,
              server_nonce: context.resPQ.server_nonce,
              retry_id: retryCount,
              g_b: gb
          }
      }).serialize();
      context.b = b;
      return context;
  }
docs: Calculate the g_b = pow(g, b) mod dh_prime Create the client DH inner data