challenge-2-padlock-secret.ipynb

{
 "cells": [
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# Challenge 2 - Padlock Secret\n",
    "\n",
    "**Difficulty level**: 3 - beginner\n",
    "\n",
    "One approach to find a password or a padlock secret combination is to use a brute force attack. Of course, for a small combination it is not a big deal, but for complex combination it could be almost impossible using the current computation power.\n",
    "\n",
    "Here, first, we will check how to create a simple brute-force attack to resolve a padlock with 3 numbers combination.\n",
    "\n",
    "When you understand how to do it, you will be ready for the challenge!"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Brute-force attack example\n",
    "\n",
    "The follow example simulates a brute-force \"attack\" that tries to resolve the padlock secret."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 1,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "All possibilities: [(0, 0, 0), (0, 0, 1), (0, 0, 2), (0, 0, 3), (0, 0, 4), (0, 0, 5), (0, 0, 6), (0, 0, 7), (0, 0, 8), (0, 0, 9), (0, 1, 0), (0, 1, 1), (0, 1, 2), (0, 1, 3), (0, 1, 4), (0, 1, 5), (0, 1, 6), (0, 1, 7), (0, 1, 8), (0, 1, 9), (0, 2, 0), (0, 2, 1), (0, 2, 2), (0, 2, 3), (0, 2, 4), (0, 2, 5), (0, 2, 6), (0, 2, 7), (0, 2, 8), (0, 2, 9), (0, 3, 0), (0, 3, 1), (0, 3, 2), (0, 3, 3), (0, 3, 4), (0, 3, 5), (0, 3, 6), (0, 3, 7), (0, 3, 8), (0, 3, 9), (0, 4, 0), (0, 4, 1), (0, 4, 2), (0, 4, 3), (0, 4, 4), (0, 4, 5), (0, 4, 6), (0, 4, 7), (0, 4, 8), (0, 4, 9), (0, 5, 0), (0, 5, 1), (0, 5, 2), (0, 5, 3), (0, 5, 4), (0, 5, 5), (0, 5, 6), (0, 5, 7), (0, 5, 8), (0, 5, 9), (0, 6, 0), (0, 6, 1), (0, 6, 2), (0, 6, 3), (0, 6, 4), (0, 6, 5), (0, 6, 6), (0, 6, 7), (0, 6, 8), (0, 6, 9), (0, 7, 0), (0, 7, 1), (0, 7, 2), (0, 7, 3), (0, 7, 4), (0, 7, 5), (0, 7, 6), (0, 7, 7), (0, 7, 8), (0, 7, 9), (0, 8, 0), (0, 8, 1), (0, 8, 2), (0, 8, 3), (0, 8, 4), (0, 8, 5), (0, 8, 6), (0, 8, 7), (0, 8, 8), (0, 8, 9), (0, 9, 0), (0, 9, 1), (0, 9, 2), (0, 9, 3), (0, 9, 4), (0, 9, 5), (0, 9, 6), (0, 9, 7), (0, 9, 8), (0, 9, 9), (1, 0, 0), (1, 0, 1), (1, 0, 2), (1, 0, 3), (1, 0, 4), (1, 0, 5), (1, 0, 6), (1, 0, 7), (1, 0, 8), (1, 0, 9), (1, 1, 0), (1, 1, 1), (1, 1, 2), (1, 1, 3), (1, 1, 4), (1, 1, 5), (1, 1, 6), (1, 1, 7), (1, 1, 8), (1, 1, 9), (1, 2, 0), (1, 2, 1), (1, 2, 2), (1, 2, 3), (1, 2, 4), (1, 2, 5), (1, 2, 6), (1, 2, 7), (1, 2, 8), (1, 2, 9), (1, 3, 0), (1, 3, 1), (1, 3, 2), (1, 3, 3), (1, 3, 4), (1, 3, 5), (1, 3, 6), (1, 3, 7), (1, 3, 8), (1, 3, 9), (1, 4, 0), (1, 4, 1), (1, 4, 2), (1, 4, 3), (1, 4, 4), (1, 4, 5), (1, 4, 6), (1, 4, 7), (1, 4, 8), (1, 4, 9), (1, 5, 0), (1, 5, 1), (1, 5, 2), (1, 5, 3), (1, 5, 4), (1, 5, 5), (1, 5, 6), (1, 5, 7), (1, 5, 8), (1, 5, 9), (1, 6, 0), (1, 6, 1), (1, 6, 2), (1, 6, 3), (1, 6, 4), (1, 6, 5), (1, 6, 6), (1, 6, 7), (1, 6, 8), (1, 6, 9), (1, 7, 0), (1, 7, 1), (1, 7, 2), (1, 7, 3), (1, 7, 4), (1, 7, 5), (1, 7, 6), (1, 7, 7), (1, 7, 8), (1, 7, 9), (1, 8, 0), (1, 8, 1), (1, 8, 2), (1, 8, 3), (1, 8, 4), (1, 8, 5), (1, 8, 6), (1, 8, 7), (1, 8, 8), (1, 8, 9), (1, 9, 0), (1, 9, 1), (1, 9, 2), (1, 9, 3), (1, 9, 4), (1, 9, 5), (1, 9, 6), (1, 9, 7), (1, 9, 8), (1, 9, 9), (2, 0, 0), (2, 0, 1), (2, 0, 2), (2, 0, 3), (2, 0, 4), (2, 0, 5), (2, 0, 6), (2, 0, 7), (2, 0, 8), (2, 0, 9), (2, 1, 0), (2, 1, 1), (2, 1, 2), (2, 1, 3), (2, 1, 4), (2, 1, 5), (2, 1, 6), (2, 1, 7), (2, 1, 8), (2, 1, 9), (2, 2, 0), (2, 2, 1), (2, 2, 2), (2, 2, 3), (2, 2, 4), (2, 2, 5), (2, 2, 6), (2, 2, 7), (2, 2, 8), (2, 2, 9), (2, 3, 0), (2, 3, 1), (2, 3, 2), (2, 3, 3), (2, 3, 4), (2, 3, 5), (2, 3, 6), (2, 3, 7), (2, 3, 8), (2, 3, 9), (2, 4, 0), (2, 4, 1), (2, 4, 2), (2, 4, 3), (2, 4, 4), (2, 4, 5), (2, 4, 6), (2, 4, 7), (2, 4, 8), (2, 4, 9), (2, 5, 0), (2, 5, 1), (2, 5, 2), (2, 5, 3), (2, 5, 4), (2, 5, 5), (2, 5, 6), (2, 5, 7), (2, 5, 8), (2, 5, 9), (2, 6, 0), (2, 6, 1), (2, 6, 2), (2, 6, 3), (2, 6, 4), (2, 6, 5), (2, 6, 6), (2, 6, 7), (2, 6, 8), (2, 6, 9), (2, 7, 0), (2, 7, 1), (2, 7, 2), (2, 7, 3), (2, 7, 4), (2, 7, 5), (2, 7, 6), (2, 7, 7), (2, 7, 8), (2, 7, 9), (2, 8, 0), (2, 8, 1), (2, 8, 2), (2, 8, 3), (2, 8, 4), (2, 8, 5), (2, 8, 6), (2, 8, 7), (2, 8, 8), (2, 8, 9), (2, 9, 0), (2, 9, 1), (2, 9, 2), (2, 9, 3), (2, 9, 4), (2, 9, 5), (2, 9, 6), (2, 9, 7), (2, 9, 8), (2, 9, 9), (3, 0, 0), (3, 0, 1), (3, 0, 2), (3, 0, 3), (3, 0, 4), (3, 0, 5), (3, 0, 6), (3, 0, 7), (3, 0, 8), (3, 0, 9), (3, 1, 0), (3, 1, 1), (3, 1, 2), (3, 1, 3), (3, 1, 4), (3, 1, 5), (3, 1, 6), (3, 1, 7), (3, 1, 8), (3, 1, 9), (3, 2, 0), (3, 2, 1), (3, 2, 2), (3, 2, 3), (3, 2, 4), (3, 2, 5), (3, 2, 6), (3, 2, 7), (3, 2, 8), (3, 2, 9), (3, 3, 0), (3, 3, 1), (3, 3, 2), (3, 3, 3), (3, 3, 4), (3, 3, 5), (3, 3, 6), (3, 3, 7), (3, 3, 8), (3, 3, 9), (3, 4, 0), (3, 4, 1), (3, 4, 2), (3, 4, 3), (3, 4, 4), (3, 4, 5), (3, 4, 6), (3, 4, 7), (3, 4, 8), (3, 4, 9), (3, 5, 0), (3, 5, 1), (3, 5, 2), (3, 5, 3), (3, 5, 4), (3, 5, 5), (3, 5, 6), (3, 5, 7), (3, 5, 8), (3, 5, 9), (3, 6, 0), (3, 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4, 3), (5, 4, 4), (5, 4, 5), (5, 4, 6), (5, 4, 7), (5, 4, 8), (5, 4, 9), (5, 5, 0), (5, 5, 1), (5, 5, 2), (5, 5, 3), (5, 5, 4), (5, 5, 5), (5, 5, 6), (5, 5, 7), (5, 5, 8), (5, 5, 9), (5, 6, 0), (5, 6, 1), (5, 6, 2), (5, 6, 3), (5, 6, 4), (5, 6, 5), (5, 6, 6), (5, 6, 7), (5, 6, 8), (5, 6, 9), (5, 7, 0), (5, 7, 1), (5, 7, 2), (5, 7, 3), (5, 7, 4), (5, 7, 5), (5, 7, 6), (5, 7, 7), (5, 7, 8), (5, 7, 9), (5, 8, 0), (5, 8, 1), (5, 8, 2), (5, 8, 3), (5, 8, 4), (5, 8, 5), (5, 8, 6), (5, 8, 7), (5, 8, 8), (5, 8, 9), (5, 9, 0), (5, 9, 1), (5, 9, 2), (5, 9, 3), (5, 9, 4), (5, 9, 5), (5, 9, 6), (5, 9, 7), (5, 9, 8), (5, 9, 9), (6, 0, 0), (6, 0, 1), (6, 0, 2), (6, 0, 3), (6, 0, 4), (6, 0, 5), (6, 0, 6), (6, 0, 7), (6, 0, 8), (6, 0, 9), (6, 1, 0), (6, 1, 1), (6, 1, 2), (6, 1, 3), (6, 1, 4), (6, 1, 5), (6, 1, 6), (6, 1, 7), (6, 1, 8), (6, 1, 9), (6, 2, 0), (6, 2, 1), (6, 2, 2), (6, 2, 3), (6, 2, 4), (6, 2, 5), (6, 2, 6), (6, 2, 7), (6, 2, 8), (6, 2, 9), (6, 3, 0), (6, 3, 1), (6, 3, 2), (6, 3, 3), (6, 3, 4), (6, 3, 5), (6, 3, 6), (6, 3, 7), (6, 3, 8), (6, 3, 9), (6, 4, 0), (6, 4, 1), (6, 4, 2), (6, 4, 3), (6, 4, 4), (6, 4, 5), (6, 4, 6), (6, 4, 7), (6, 4, 8), (6, 4, 9), (6, 5, 0), (6, 5, 1), (6, 5, 2), (6, 5, 3), (6, 5, 4), (6, 5, 5), (6, 5, 6), (6, 5, 7), (6, 5, 8), (6, 5, 9), (6, 6, 0), (6, 6, 1), (6, 6, 2), (6, 6, 3), (6, 6, 4), (6, 6, 5), (6, 6, 6), (6, 6, 7), (6, 6, 8), (6, 6, 9), (6, 7, 0), (6, 7, 1), (6, 7, 2), (6, 7, 3), (6, 7, 4), (6, 7, 5), (6, 7, 6), (6, 7, 7), (6, 7, 8), (6, 7, 9), (6, 8, 0), (6, 8, 1), (6, 8, 2), (6, 8, 3), (6, 8, 4), (6, 8, 5), (6, 8, 6), (6, 8, 7), (6, 8, 8), (6, 8, 9), (6, 9, 0), (6, 9, 1), (6, 9, 2), (6, 9, 3), (6, 9, 4), (6, 9, 5), (6, 9, 6), (6, 9, 7), (6, 9, 8), (6, 9, 9), (7, 0, 0), (7, 0, 1), (7, 0, 2), (7, 0, 3), (7, 0, 4), (7, 0, 5), (7, 0, 6), (7, 0, 7), (7, 0, 8), (7, 0, 9), (7, 1, 0), (7, 1, 1), (7, 1, 2), (7, 1, 3), (7, 1, 4), (7, 1, 5), (7, 1, 6), (7, 1, 7), (7, 1, 8), (7, 1, 9), (7, 2, 0), (7, 2, 1), (7, 2, 2), (7, 2, 3), (7, 2, 4), (7, 2, 5), (7, 2, 6), (7, 2, 7), (7, 2, 8), (7, 2, 9), (7, 3, 0), (7, 3, 1), (7, 3, 2), (7, 3, 3), (7, 3, 4), (7, 3, 5), (7, 3, 6), (7, 3, 7), (7, 3, 8), (7, 3, 9), (7, 4, 0), (7, 4, 1), (7, 4, 2), (7, 4, 3), (7, 4, 4), (7, 4, 5), (7, 4, 6), (7, 4, 7), (7, 4, 8), (7, 4, 9), (7, 5, 0), (7, 5, 1), (7, 5, 2), (7, 5, 3), (7, 5, 4), (7, 5, 5), (7, 5, 6), (7, 5, 7), (7, 5, 8), (7, 5, 9), (7, 6, 0), (7, 6, 1), (7, 6, 2), (7, 6, 3), (7, 6, 4), (7, 6, 5), (7, 6, 6), (7, 6, 7), (7, 6, 8), (7, 6, 9), (7, 7, 0), (7, 7, 1), (7, 7, 2), (7, 7, 3), (7, 7, 4), (7, 7, 5), (7, 7, 6), (7, 7, 7), (7, 7, 8), (7, 7, 9), (7, 8, 0), (7, 8, 1), (7, 8, 2), (7, 8, 3), (7, 8, 4), (7, 8, 5), (7, 8, 6), (7, 8, 7), (7, 8, 8), (7, 8, 9), (7, 9, 0), (7, 9, 1), (7, 9, 2), (7, 9, 3), (7, 9, 4), (7, 9, 5), (7, 9, 6), (7, 9, 7), (7, 9, 8), (7, 9, 9), (8, 0, 0), (8, 0, 1), (8, 0, 2), (8, 0, 3), (8, 0, 4), (8, 0, 5), (8, 0, 6), (8, 0, 7), (8, 0, 8), (8, 0, 9), (8, 1, 0), (8, 1, 1), (8, 1, 2), (8, 1, 3), (8, 1, 4), (8, 1, 5), (8, 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0, 7), (9, 0, 8), (9, 0, 9), (9, 1, 0), (9, 1, 1), (9, 1, 2), (9, 1, 3), (9, 1, 4), (9, 1, 5), (9, 1, 6), (9, 1, 7), (9, 1, 8), (9, 1, 9), (9, 2, 0), (9, 2, 1), (9, 2, 2), (9, 2, 3), (9, 2, 4), (9, 2, 5), (9, 2, 6), (9, 2, 7), (9, 2, 8), (9, 2, 9), (9, 3, 0), (9, 3, 1), (9, 3, 2), (9, 3, 3), (9, 3, 4), (9, 3, 5), (9, 3, 6), (9, 3, 7), (9, 3, 8), (9, 3, 9), (9, 4, 0), (9, 4, 1), (9, 4, 2), (9, 4, 3), (9, 4, 4), (9, 4, 5), (9, 4, 6), (9, 4, 7), (9, 4, 8), (9, 4, 9), (9, 5, 0), (9, 5, 1), (9, 5, 2), (9, 5, 3), (9, 5, 4), (9, 5, 5), (9, 5, 6), (9, 5, 7), (9, 5, 8), (9, 5, 9), (9, 6, 0), (9, 6, 1), (9, 6, 2), (9, 6, 3), (9, 6, 4), (9, 6, 5), (9, 6, 6), (9, 6, 7), (9, 6, 8), (9, 6, 9), (9, 7, 0), (9, 7, 1), (9, 7, 2), (9, 7, 3), (9, 7, 4), (9, 7, 5), (9, 7, 6), (9, 7, 7), (9, 7, 8), (9, 7, 9), (9, 8, 0), (9, 8, 1), (9, 8, 2), (9, 8, 3), (9, 8, 4), (9, 8, 5), (9, 8, 6), (9, 8, 7), (9, 8, 8), (9, 8, 9), (9, 9, 0), (9, 9, 1), (9, 9, 2), (9, 9, 3), (9, 9, 4), (9, 9, 5), (9, 9, 6), (9, 9, 7), (9, 9, 8), (9, 9, 9)] \n",
      "\n",
      "The guess ((6, 1, 3)) was correct!\n",
      "execution time: 0.00034308433532714844\n"
     ]
    }
   ],
   "source": [
    "import itertools\n",
    "import random\n",
    "import time\n",
    "\n",
    "lock_secret = (\n",
    "    random.randint(0, 9),\n",
    "    random.randint(0, 9),\n",
    "    random.randint(0, 9),\n",
    ")\n",
    "  \n",
    "possibilities = list(\n",
    "    itertools.product(range(10), repeat=len(lock_secret))\n",
    ")\n",
    "\n",
    "print('All possibilities:', possibilities, '\\n')\n",
    "\n",
    "t0 = time.time()\n",
    "\n",
    "# brute-force attack\n",
    "for guess in possibilities:\n",
    "    if guess == lock_secret:\n",
    "        print(f'The guess ({guess}) was correct!')\n",
    "        break\n",
    "print('execution time:', time.time() - t0)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Socket example\n",
    "\n",
    "This example shows how to create a socket and a client that communicates between them.\n",
    "It uses `multiprocessing.Process` to run the server and client code in a different system process.\n",
    "Using this approach, we can run server and client code in parallel."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 2,
   "metadata": {},
   "outputs": [],
   "source": [
    "import socket\n",
    "import requests  # pip install requests\n",
    "import multiprocessing as mp\n",
    "import time"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "metadata": {},
   "outputs": [],
   "source": [
    "HOST = '127.0.0.1'  # Standard loopback interface address (localhost)\n",
    "PORT = 58123        # Port to listen on (non-privileged ports are > 1023)\n",
    "BUFSIZE = 1024      # Buffer size"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 4,
   "metadata": {},
   "outputs": [],
   "source": [
    "# SERVER\n",
    "def server(host: str='127.0.0.1', port: int=58123, bufsize: int=1024):        \n",
    "    with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:\n",
    "        print(f'server: binding {host}:{port}')\n",
    "        s.bind((host, port))\n",
    "        \n",
    "        print('server: listening ...')\n",
    "        s.listen()\n",
    "        \n",
    "        \n",
    "        print('server: accepting connection ...')\n",
    "        conn, addr = s.accept()\n",
    "        with conn:\n",
    "            print('server: connected by', addr)\n",
    "            while True:\n",
    "                print('server: receiving data ...')\n",
    "                data = conn.recv(bufsize)\n",
    "                if not data:\n",
    "                    break\n",
    "                print('server: sending data ...')\n",
    "                conn.sendall(data) \n",
    "    print('server: done.')"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 5,
   "metadata": {},
   "outputs": [],
   "source": [
    "# CLIENT\n",
    "def client(server_host: str='127.0.0.1', server_port: int=58123, bufsize: int=1024):\n",
    "    with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:\n",
    "        print(f'client: connecting to the server {server_host}:{server_port}')\n",
    "        s.connect((HOST, PORT))\n",
    "        print('client: sending data ...')\n",
    "        s.sendall(b'Hello, world')\n",
    "        data = s.recv(bufsize)\n",
    "\n",
    "    print('client: Data received', repr(data))\n",
    "    print('client: done.')"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 6,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "main: starting server ...\n",
      "server: binding 127.0.0.1:58123\n",
      "server: listening ...\n",
      "server: accepting connection ...\n",
      "main: starting client ...\n",
      "client: connecting to the server 127.0.0.1:58123\n",
      "client: sending data ...server: connected by\n",
      " ('127.0.0.1', 33314)\n",
      "server: receiving data ...\n",
      "server: sending data ...\n",
      "client: Data receivedserver: receiving data ...\n",
      " server: done.b'Hello, world'\n",
      "\n",
      "client: done.\n"
     ]
    }
   ],
   "source": [
    "# create server and client processes\n",
    "p_server = mp.Process(target=server, args=(HOST, PORT, BUFSIZE))\n",
    "p_client = mp.Process(target=client, args=(HOST, PORT, BUFSIZE))\n",
    "\n",
    "# start both processes\n",
    "print(\"main: starting server ...\")\n",
    "p_server.start()\n",
    "\n",
    "time.sleep(1)\n",
    "\n",
    "print(\"main: starting client ...\")\n",
    "p_client.start()\n",
    "\n",
    "\n",
    "# wait and finish all the processes\n",
    "p_server.join()\n",
    "p_client.join()"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Challenge\n",
    "\n",
    "- Create a socket code (server) and a client code.\n",
    "- Create a socket (server) that generates a random lock_secret with 3 numbers and receive a guess from a client.\n",
    "- If the guess is correct, the socket returns '{\"is_correct\": true}' and client stops the iteration.\n",
    "- If the guess is NOT correct, return '{\"is_correct\": false}' and client continues the iteration."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 7,
   "metadata": {},
   "outputs": [],
   "source": [
    "# your code here!"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## References\n",
    "\n",
    "- https://en.wikipedia.org/wiki/Permutation\n",
    "- https://en.wikipedia.org/wiki/Combination\n",
    "- https://www.geeksforgeeks.org/permutation-and-combination-in-python/\n",
    "- https://docs.python.org/3.8/library/itertools.html\n",
    "- https://docs.python.org/3/library/socket.html\n",
    "- https://realpython.com/python-sockets/"
   ]
  }
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