api_plugin for api-nodejs

ddos.js

const redis = require('../modules/RedisClientAPI').redis;
const random = require('../modules/random');
const config = require('../modules/config');
const Promise = require("bluebird");
const {promisify} = require('util');
const redisAsync = {
  get: promisify(redis.get).bind(redis),
  del: promisify(redis.del).bind(redis),
  ttl: promisify(redis.ttl).bind(redis),
  set: promisify(redis.set).bind(redis),
};

function DDOS_Error(time) {
  if (time < 0) time = 1;
  time += 1;

  let stack_ = (new Error()).stack.replace(new RegExp('    ', 'g'), '').replace(new RegExp('at ', 'g'), '').replace(new RegExp('Promise.(.*).err', 'g'), 'Promise').split("\n");
  let message_stack = '';
  if (stack_[2] && stack_[2].indexOf('bluebird') === -1 && stack_[2].indexOf('modules/error/api') === -1) message_stack += stack_[2];
  if (stack_[3] && stack_[3].indexOf('bluebird') === -1 && stack_[3].indexOf('modules/error/api') === -1) message_stack += '\n' + stack_[3];
  if (stack_[4] && stack_[4].indexOf('bluebird') === -1 && stack_[4].indexOf('modules/error/api') === -1) message_stack += '\n' + stack_[4];
  if (stack_[5] && stack_[5].indexOf('bluebird') === -1 && stack_[5].indexOf('modules/error/api') === -1) message_stack += '\n' + stack_[5];
  if (stack_[6] && stack_[6].indexOf('bluebird') === -1 && stack_[6].indexOf('modules/error/api') === -1) message_stack += '\n' + stack_[6];
  if (stack_[7] && stack_[7].indexOf('bluebird') === -1 && stack_[7].indexOf('modules/error/api') === -1) message_stack += '\n' + stack_[7];
  if (stack_[8] && stack_[8].indexOf('bluebird') === -1 && stack_[8].indexOf('modules/error/api') === -1) message_stack += '\n' + stack_[8];
  if (stack_[9] && stack_[9].indexOf('bluebird') === -1 && stack_[9].indexOf('modules/error/api') === -1) message_stack += '\n' + stack_[9];
  return {
    apiError: true,
    message: "DDOS flood! Try after: " + time + " second(s).",
    errorType: 'api',
    level: 0,
    errorCode: 5030000,
    stack: (!!config.get('server:api:debug:stack')) ? message_stack : undefined,
  }
}

async function checkLockApi(key, floodSign, delay) {
  const key_method = 'lock-method-' + key;
  if (delay)
    await Promise.delay(delay);

  const value = await redisAsync.get(key_method);
  if (value !== floodSign) {
    const time = await redisAsync.ttl(key_method);
    if (time === -1)
      await redisAsync.del(key_method);
    return Promise.reject(DDOS_Error(time));
  }
  return true

}

async function lockApi(key, block_sec) {
  await checkLockApi(key, null);
  const sign = Date.now() + random.str(10, 10);
  const key_method = 'lock-method-' + key;
  await redisAsync.set(key_method, sign, 'EX', block_sec);

  return sign
}

/** @name API.plugin.ddos */
module.exports = {checkLockApi: checkLockApi, lockApi: lockApi};


//docs

// auth.ddosKey = 'balance-inc-' + auth.user._id;
// const floodSign = await API.plugin.ddos.lockApi(auth.ddosKey, 10);  // s
// await API.plugin.ddos.checkLockApi(auth.ddosKey, floodSign, 50);// delay before check ms