_Client.ipynb

{
 "cells": [
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "\n",
    " \tCreator Name:   Sara Baradaran, Mahdi Heidari\t\t\n",
    " \tCreate Date:    Aug 2020 \t\t\t\t\n",
    " \tModule Name:    Client.py \t\t\t\t\n",
    " \tProject Name:   Secure File Sharing \t"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "import os\n",
    "import socket\n",
    "import hashlib\n",
    "import base64\n",
    "import random\n",
    "from Crypto.Util import Counter\n",
    "from Crypto import Random\n",
    "import string\n",
    "import json\n",
    "from datetime import datetime\n",
    "from cryptography.hazmat.backends import default_backend\n",
    "from cryptography.hazmat.primitives import hashes,serialization\n",
    "from cryptography.hazmat.primitives.asymmetric import ec\n",
    "from cryptography.hazmat.primitives.kdf.hkdf import HKDF\n",
    "from Crypto.Cipher import AES\n",
    "from captcha.image import ImageCaptcha"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "\n",
    "AouthCode = '0'\n",
    "\n",
    "def connection_setup():\n",
    "    s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)\n",
    "    if s == 0:\n",
    "        print ('ERROR: Unable to create client socket')\n",
    "        return None\n",
    "    server_ip = socket.gethostname()\n",
    "    server_port = 8500\n",
    "    s.connect((server_ip, server_port))\n",
    "    print(\"Connecting to server ... \")\n",
    "    return s\n",
    "\n",
    "def send_command(s, key, command): # Returns 1 if successful, otherwise 0\n",
    "    cipher_text = encrypt(command, key)\n",
    "    if cipher_text != None:\n",
    "        s.send(cipher_text.encode('utf-8'))\n",
    "        return 1\n",
    "    print('ERROR: Can not encrypt request to send.')\n",
    "    return 0\n",
    "\n",
    "def recieve_replay(s, key): # Returns reply if successful, otherwise None\n",
    "    replay = s.recv(500)\n",
    "    replay = replay.decode('utf-8')\n",
    "    plain_text = decrypt(replay, key)\n",
    "    #print(plain_text)\n",
    "    if plain_text != None:\n",
    "        return plain_text\n",
    "    print('ERROR: Can not decrypt response.')\n",
    "    return None"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "\n",
    "def key_exchange(client_sock): # makes a private key, sends and receives public keys, derives the secret key and returns session key\n",
    "\n",
    "    try:\n",
    "        backend = default_backend()\n",
    "        client_pr = ec.generate_private_key(ec.SECP256R1(), backend)\n",
    "        client_pub = client_pr.public_key()\n",
    "        client_sock.send(client_pub.public_bytes(serialization.Encoding.PEM, serialization.PublicFormat.SubjectPublicKeyInfo))\n",
    "        server_rcv_pub = client_sock.recv(200) # server_rcv_pub is server received public key in bytes\n",
    "        server_pub = serialization.load_pem_public_key(server_rcv_pub, backend)# server_pub is server  public key in curve object\n",
    "        shared_data = client_pr.exchange(ec.ECDH(), server_pub)\n",
    "        secret_key = HKDF(hashes.SHA256(), 32, None, b'Key Exchange', backend).derive(shared_data)\n",
    "        session_key = secret_key[-16:] # to choose the last 128 bit of secret key\n",
    "        print('Key exchanged successfully.')\n",
    "        return session_key\n",
    "    except:\n",
    "        print('ERROR: Server blocked the connection because no session key has been set.\\n')\n",
    "        return None\n",
    "\n",
    "def encrypt(plain_text, key): # returns a json containing ciphertext and nonce for CTR mode\n",
    "    \n",
    "    nonce1 = Random.get_random_bytes(8)\n",
    "    countf = Counter.new(64, nonce1)\n",
    "    cipher = AES.new(key, AES.MODE_CTR, counter=countf)\n",
    "    cipher_text_bytes = cipher.encrypt(plain_text.encode('utf-8'))\n",
    "    nonce = base64.b64encode(nonce1).decode('utf-8')\n",
    "    cipher_text = base64.b64encode(cipher_text_bytes).decode('utf-8')\n",
    "    result = json.dumps({'nonce':nonce, 'ciphertext':cipher_text})\n",
    "    return result\n",
    "\n",
    "def decrypt(data, key):\n",
    "\n",
    "    try:\n",
    "        b64 = json.loads(data)\n",
    "        nonce = base64.b64decode(b64['nonce'].encode('utf-8'))\n",
    "        cipher_text = base64.b64decode(b64['ciphertext'])\n",
    "        countf = Counter.new(64, nonce)\n",
    "        cipher = AES.new(key, AES.MODE_CTR, counter=countf)\n",
    "        plain_text = cipher.decrypt(cipher_text)\n",
    "        return plain_text.decode('utf-8')\n",
    "    except ValueError:\n",
    "        return None\n"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "\n",
    "def proccess_command(s, key, command):\n",
    "    global AouthCode\n",
    "    cmd = command.split()    \n",
    "    if cmd[0] == \"register\" and len(cmd) == 5:\n",
    "        if send_command(s, key, command) == 0:\n",
    "            return 0\n",
    "        replay = recieve_replay(s, key)\n",
    "        \n",
    "        if replay == None:\n",
    "            return 0\n",
    "        replay = replay.split(\"\\n\")\n",
    "        if len(replay) > 1:\n",
    "            content = replay[1]\n",
    "        replay = replay[0]\n",
    "        replay = replay.split()\n",
    "        if replay[1] == \"register\" and replay[2] == cmd[1]:\n",
    "            if replay[0] == \"1\":\n",
    "                print(\"Registered successfully\")\n",
    "                return 1  # Registered successfully\n",
    "            elif replay[0] == \"0\":\n",
    "                print(\"ERROR: Registeration failed try again\") #systematic error\n",
    "                return 0 # Registeration failed\n",
    "            elif replay[0] == \"-2\":\n",
    "                print(\"ERROR: This username already exists. Please select another one.\")\n",
    "                return 0\n",
    "            elif replay[0] == \"-3\":\n",
    "                print(\"ERROR: Password is not strong enough.({})\".format(content))\n",
    "                return 0\n",
    "\n",
    "    elif cmd[0] == \"login\" and len(cmd) == 3:\n",
    "        if send_command(s, key, command) == 0:\n",
    "            return 0\n",
    "        replay = recieve_replay(s, key)\n",
    "        \n",
    "        if replay == None:\n",
    "            return 0\n",
    "        replay = replay.split(\"\\n\")\n",
    "        content = replay[1]\n",
    "        AouthCode = replay[2]\n",
    "        replay = replay[0].split()\n",
    "        #print('get AouthCode',AouthCode)\n",
    "        if replay[1] == \"login\" and replay[2] == cmd[1]:\n",
    "            if replay[0] == \"0\":\n",
    "                print(\"ERROR: Login was not successfull try again\")\n",
    "                return 0\n",
    "            elif replay[0] == \"1\":\n",
    "                print(\"Logged in successfully\")\n",
    "                return 1\n",
    "            elif replay[0] == \"-1\":\n",
    "                print(\"ERROR: Username and password do not match. Please try again\")\n",
    "                return 0\n",
    "            elif replay[0] == \"-4\":\n",
    "                print(\"ERROR: Your Account is ban for {} minute. try again later\".format(content))\n",
    "                return 0"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "   \n",
    "def after_login(s, key, command):\n",
    "    global AouthCode\n",
    "    content = ''\n",
    "    replay = ''\n",
    "    data = command.split(\"\\n\",1)\n",
    "    cmd = data[0].split()\n",
    "    if len(data) > 1:\n",
    "        content = data[1] # to enable writing for more than a line\n",
    "    \n",
    "    if cmd[0] == \"grant\" and len(cmd) == 4:  \n",
    "        if send_command(s, key, command + '\\n' + AouthCode) == 0:\n",
    "            return 0\n",
    "        replay = recieve_replay(s, key)\n",
    "        if replay == None:\n",
    "            return 0\n",
    "        replay = replay.split()\n",
    "        if replay[1] == \"grant\" and replay[2] == cmd[1] and replay[3] == cmd[2]:\n",
    "            if replay[0] == \"1\":\n",
    "                print(\"Grant access was successfull\")\n",
    "\n",
    "            elif replay[0] == \"0\": \n",
    "                print(\"ERROR: Grant access was not successfull(permission denied)\")\n",
    "            \n",
    "            if replay[0] == \"-1\":\n",
    "                print(\"ERROR: Authentication failing\")\n",
    "\n",
    "            elif replay[0] == \"-2\":  \n",
    "                print(\"ERROR: There is no such file\")\n",
    "                 \n",
    "    if cmd[0] == \"revoce\" and len(cmd) == 4:  \n",
    "        if send_command(s, key, command + '\\n' + AouthCode) == 0:\n",
    "            return 0\n",
    "        replay = recieve_replay(s, key)\n",
    "        \n",
    "        if replay == None:\n",
    "            return 0\n",
    "        replay = replay.split()\n",
    "        if replay[1] == \"revoce\" and replay[2] == cmd[1] and replay[3] == cmd[2]:\n",
    "            if replay[0] == \"1\":\n",
    "                print(\"Revoce access was successfull\")\n",
    "\n",
    "            elif replay[0] == \"0\": \n",
    "                print(\"ERROR: Revoce access was not successfull(permission denied)\")\n",
    "            \n",
    "            if replay[0] == \"-1\":\n",
    "                print(\"ERROR: Authentication failing\")\n",
    "\n",
    "            elif replay[0] == \"-2\":  \n",
    "                print(\"ERROR: There is no such file\")\n",
    "\n",
    "    if cmd[0] == \"write\" and len(cmd) == 2:  \n",
    "        if send_command(s, key, cmd[0]+ ' ' + cmd[1] + '\\n' + content + '\\n' + AouthCode) == 0:\n",
    "            return 0    \n",
    "        replay = recieve_replay(s, key)\n",
    "        \n",
    "        if replay == None:\n",
    "            return 0\n",
    "        replay = replay.split()\n",
    "        if replay[3] == \"write\" and replay[4] == cmd[1]:\n",
    "\n",
    "            if replay[0] == \"1\":\n",
    "                print(\"Writing in file was successful\")\n",
    "\n",
    "            elif replay[0] == \"0\" and replay[1] == \"1\" and replay[2] == \"1\":   \n",
    "                print(\"ERROR: Writing in file was not successfull try again\")\n",
    "\n",
    "            else:\n",
    "                print(\"ERROR: Writing in file was not successfull : BLP_status = {} : BIBA_status = {}\".format(replay[1], replay[2]))\n",
    "        elif replay[1] == \"write\" and replay[2] == cmd[1]:\n",
    "            \n",
    "            if replay[0] == \"-1\":\n",
    "                print(\"ERROR: Authentication failing\")\n",
    "\n",
    "            elif replay[0] == \"-2\":  \n",
    "                print(\"ERROR: There is no such file for writing\")\n",
    "\n",
    "\n",
    "    if cmd[0] == \"read\" and len(cmd) == 2:  \n",
    "        if send_command(s, key, command + '\\n' + AouthCode) == 0:\n",
    "            return 0\n",
    "        replay = recieve_replay(s, key)\n",
    "        \n",
    "        if replay == None:\n",
    "            return 0\n",
    "        replay = replay.split(\"\\n\",1)\n",
    "        content = replay[1]\n",
    "        replay = replay[0].split()\n",
    "        if replay[3] == \"read\" and replay[4] == cmd[1]:\n",
    "\n",
    "            if replay[0] == \"1\":\n",
    "                print(\"File content :\\n{}\".format(content))\n",
    "\n",
    "            elif replay[0] == \"0\" and replay[1] == \"1\" and replay[2] == \"1\":\n",
    "                print(\"ERROR: Reading file was not successfull try again\")\n",
    "\n",
    "            else:\n",
    "                print(\"ERROR: Reading file was not successfull : BLP_status = {} : BIBA_status = {}\".format(replay[1], replay[2]))\n",
    "        elif replay[1] == \"read\" and replay[2] == cmd[1]:\n",
    "            \n",
    "            if replay[0] == \"-1\":\n",
    "                print(\"ERROR: Authentication failing\")\n",
    "\n",
    "            elif replay[0] == \"-2\":  \n",
    "                print(\"ERROR: There is no such file for reading\")\n",
    "\n",
    "    if cmd[0] == \"get\" and len(cmd) == 2:\n",
    "        if send_command(s, key, command + \"\\n\" + AouthCode) == 0:\n",
    "            return 0\n",
    "        replay = recieve_replay(s, key)\n",
    "        \n",
    "        if replay == None:\n",
    "            return 0\n",
    "        replay = replay.split(\"\\n\",1)\n",
    "        content = replay[1]\n",
    "        replay = replay[0].split()\n",
    "        \n",
    "        if replay[1] == \"get\" and replay[2] == cmd[1]:\n",
    "            if replay[0] == \"1\":\n",
    "                f = open(cmd[1], \"w\")\n",
    "                if f == 0:\n",
    "                    print(\"ERROR: File is not created on your system\")\n",
    "                else:\n",
    "                    f.write(content)\n",
    "                    print(\"Getting file was successful\")\n",
    "                f.close()\n",
    "\n",
    "            elif replay[0] == \"0\":  \n",
    "                print(\"ERROR: Getting file was not successfull (permission denied)\")\n",
    "\n",
    "            elif replay[0] == \"-1\":\n",
    "                print(\"ERROR: Authentication failing\")\n",
    "            \n",
    "            elif replay[0] == \"-2\":  \n",
    "                print(\"ERROR: There is no such file for getting\")\n",
    "\n",
    "    if cmd[0] == \"put\" and len(cmd) == 5:\n",
    "        if (os.path.isfile('./' + cmd[1])):\n",
    "            f = open(cmd[1], \"r\")\n",
    "            if f == 0:\n",
    "                print(\"ERROR: File could not be opened or file does not exist on your system\")\n",
    "            else:\n",
    "                content = f.read()\n",
    "                f.close()\n",
    "                if send_command(s, key, command + \"\\n\" + content + \"\\n\" + AouthCode) == 0:\n",
    "                    return 0\n",
    "                replay = recieve_replay(s, key)\n",
    "                if replay == None:\n",
    "                    return 0\n",
    "                replay = replay.split()\n",
    "                if replay[1] == \"put\" and replay[2] == cmd[1]:\n",
    "                    if replay[0] == \"0\":\n",
    "                        print(\"ERROR: Putting file was not successfull try again\")\n",
    "\n",
    "                    elif replay[0] == \"1\":\n",
    "                        print(\"Putting file was successfull\")\n",
    "\n",
    "                    elif replay[0] == \"-1\":\n",
    "                        print(\"ERROR: Authentication failing\")\n",
    "\n",
    "                    elif replay[0] == \"-2\":  \n",
    "                        print(\"ERROR: There is such file on server\")\n",
    "        else:\n",
    "            print(\"ERROR: There is not such file on your system\")\n",
    "\n",
    "    if cmd[0] == \"list\" and len(cmd) == 1:\n",
    "        \n",
    "        if send_command(s, key, command + '\\n' + AouthCode) == 0:\n",
    "            return 0        \n",
    "        msg = \"list\"\n",
    "        replay = recieve_replay(s, key)\n",
    "        if replay == None:\n",
    "            return 0\n",
    "        print(replay)\n",
    "        replay = replay.split(\"\\n\",1)\n",
    "        content = replay[1]\n",
    "        replay = replay[0].split()\n",
    "        if replay[1] == \"read\" and replay[4] == cmd[1]:\n",
    "\n",
    "            if replay[0] == \"1\":\n",
    "                print(\"Files list :\\n{}\".format(content))\n",
    "\n",
    "            elif replay[0] == \"0\":\n",
    "                print(\"ERROR: Listing files was not successfull try again\")\n",
    "\n",
    "            if replay[0] == \"-1\":\n",
    "                print(\"ERROR: Authentication failing\")\n",
    "\n",
    "    if cmd[0] == \"logout\" and len(cmd) == 1:\n",
    "\n",
    "        if send_command(s, key, command + '\\n' + AouthCode) == 0:\n",
    "            return 0\n",
    "        replay = recieve_replay(s, key)\n",
    "        \n",
    "        if replay == None:\n",
    "            return 0\n",
    "        replay = replay.split()\n",
    "        if replay[1] == \"logout\":\n",
    "            \n",
    "            if replay[0] == \"0\":\n",
    "                print(\"ERROR: Logout was not successfull try again\")\n",
    "\n",
    "            elif replay[0] == \"1\":\n",
    "                print(\"Logout was successfull\")\n",
    "                AouthCode = '0'\n",
    "\n",
    "            elif replay[0] == \"-1\":\n",
    "                print(\"ERROR: Authentication failing\")\n"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "\n",
    "\n",
    "def register(client_sock, key): # Returns 1 if successfully registered, otherwise 0\n",
    "    \n",
    "    os.system('cls')\n",
    "    input_range = ['1', '2', '3', '4']\n",
    "    while True:\n",
    "        username = input('Please enter a Username : ')\n",
    "        if username.count(' ') == 0 and username.count('\\\\') == 0: # backslash(like \\n, \\t,...) and spaces may be splitted in commands\n",
    "            break\n",
    "        else:\n",
    "            print('Username can not contain space or backslash.')\n",
    "    os.system('cls')\n",
    "    while True:\n",
    "        password = input('Please enter a Password : ')\n",
    "        if password.count(' ') == 0 and password.count('\\\\') == 0:\n",
    "            break\n",
    "        else:\n",
    "            print('Password can not contain space or backslash.')\n",
    "    os.system('cls')\n",
    "    while True:\n",
    "        conf_label = input('Please choose your Confidentiality level :\\n4.‫‪Top Secret‬‬\\n3.Secret\\n2.Confidential\\n1.Unclassified\\n')\n",
    "        if conf_label in input_range:\n",
    "            break\n",
    "    os.system('cls')\n",
    "    while True:\n",
    "        integrity_label = input('Please choose your Integrity level :\\n4.‫‪Very Trusted‬‬\\n3.Trusted‬‬\\n2.SlightlyTrusted\\n1.Untrusted‬‬\\n')\n",
    "        if integrity_label in input_range:\n",
    "            break\n",
    "    os.system('cls')\n",
    "    command = 'register '+ username +' '+ password +' '+ conf_label +' '+ integrity_label\n",
    "    if proccess_command(client_sock, key, command) == 1:\n",
    "        input('Press enter to continue...\\n')\n",
    "        return 1\n",
    "    input('Press enter to continue...\\n')\n",
    "    return 0\n",
    "\n",
    "def login(client_sock, key):\n",
    "\n",
    "    os.system('cls')\n",
    "    while True:\n",
    "        username = input('Please enter Username : ')\n",
    "        if username.count(' ') == 0 and username.count('\\\\') == 0:\n",
    "            break\n",
    "        else:\n",
    "            print('Username can not contain space or backslash.')\n",
    "    os.system('cls')\n",
    "    while True:\n",
    "        password = input('Please enter Password : ')\n",
    "        if password.count(' ') == 0 and password.count('\\\\') == 0:\n",
    "            break\n",
    "        else:\n",
    "            print('Password can not contain space or backslash.')\n",
    "    os.system('cls')\n",
    "    while True:\n",
    "        if random_captcha() == 1:\n",
    "            print('Correct answer')\n",
    "            break\n",
    "        print('Wrong answer.Try again')\n",
    "    os.system('cls')\n",
    "    command = 'login '+ username +' '+ password\n",
    "    if proccess_command(client_sock, key, command) == 1:\n",
    "        input('Press enter to continue...\\n')\n",
    "        return 1\n",
    "    input('Press enter to continue...\\n')\n",
    "    return 0\n",
    "\n",
    "def put(client_sock, key):\n",
    "\n",
    "    os.system('cls')\n",
    "    while True:\n",
    "        filename = input('Please enter the File name : ')\n",
    "        if filename.count(' ') == 0 and filename.count('\\\\') == 0:\n",
    "            break\n",
    "        else:\n",
    "            print('Filename can not contain space or backslash.')\n",
    "    os.system('cls')\n",
    "    input_range = ['1', '2', '3', '4']\n",
    "    \n",
    "    #conflabel_range = ['TopSecret', 'Secret', 'Confidential', 'Unclassified']\n",
    "    #intlabel_range = ['VeryTrusted', 'Trusted', 'Slightly Trusted', 'UnTrusted']\n",
    "    \n",
    "    while True:\n",
    "        conf_label = input('Please choose file Confidentiality level :\\n4.‫‪Top Secret‬‬\\n3.Secret\\n2.Confidential\\n1.Unclassified\\n')\n",
    "        if conf_label in input_range:\n",
    "            break\n",
    "    os.system('cls')\n",
    "    while True:\n",
    "        integrity_label = input('Please choose file Integrity level :\\n4.‫‪Very Trusted‬‬\\n3.Trusted‬‬\\n2.SlightlyTrusted\\n1.Untrusted‬‬\\n')\n",
    "        if integrity_label in input_range:\n",
    "            break\n",
    "    os.system('cls')\n",
    "    access_modes = input('Please choose access modes(2.BLP, 3.BIBA, 5.DAC‬‬)\\n')\n",
    "    access_modes = [char for char in access_modes]\n",
    "    cond = 1\n",
    "    for i in access_modes:\n",
    "        cond = cond * int(i)\n",
    "   \n",
    "    os.system('cls')\n",
    "    command = 'put '+ filename +' '+ conf_label +' '+ integrity_label + ' ' + str(cond)\n",
    "    after_login(client_sock, key, command)\n",
    "    input('Press enter to continue...\\n')\n",
    "    \n",
    "    \n",
    "def get(client_sock, key):\n",
    "\n",
    "    os.system('cls')\n",
    "    while True:\n",
    "        filename = input('Please enter the File name : ')\n",
    "        if filename.count(' ') == 0 and filename.count('\\\\') == 0:\n",
    "            break\n",
    "        else:\n",
    "            print('Filename can not contain space or backslash.')\n",
    "    os.system('cls')\n",
    "    command = 'get '+ filename\n",
    "    after_login(client_sock, key, command)\n",
    "    input('Press enter to continue...\\n')\n",
    "\n",
    "def read(client_sock, key):\n",
    "    \n",
    "    os.system('cls')\n",
    "    while True:\n",
    "        filename = input('Please enter the File name : ')\n",
    "        if filename.count(' ') == 0 and filename.count('\\\\') == 0:\n",
    "            break\n",
    "        else:\n",
    "            print('Filename can not contain space or backslash.')\n",
    "    os.system('cls')\n",
    "    command = 'read '+ filename\n",
    "    after_login(client_sock, key, command)\n",
    "    input('Press enter to continue...\\n')\n",
    "\n",
    "def list_files(client_sock, key):\n",
    "    \n",
    "    os.system('cls')\n",
    "    command = 'list'\n",
    "    after_login(client_sock, key, command)\n",
    "    input('Press enter to continue...\\n')\n",
    "\n",
    "def write(client_sock, key):\n",
    "\n",
    "    os.system('cls')\n",
    "    while True:\n",
    "        filename = input('Please enter the File name : ')\n",
    "        if filename.count(' ') == 0 and filename.count('\\\\') == 0:\n",
    "            break\n",
    "        else:\n",
    "            print('Filename can not contain space or backslash.')\n",
    "    \n",
    "    print('Please input the content. Type \"end\" to finish')\n",
    "    lines = []\n",
    "    while True:\n",
    "        line = input()\n",
    "        if line != 'end':\n",
    "            lines.append(line)\n",
    "        else:\n",
    "            break\n",
    "    text = '\\n'.join(lines)\n",
    "    command = 'write '+ filename + '\\n' + text\n",
    "    input('Press enter to continue...\\n')\n",
    "    os.system('cls')\n",
    "    after_login(client_sock, key, command)\n",
    "    input('Press enter to continue...\\n')\n",
    "\n",
    "def grant(client_sock, key):\n",
    "\n",
    "    os.system('cls')\n",
    "    while True:\n",
    "        filename = input('Please enter the File name : ')\n",
    "        if filename.count(' ') == 0 and filename.count('\\\\') == 0:\n",
    "            break\n",
    "        else:\n",
    "            print('Filename can not contain space or backslash.')\n",
    "    os.system('cls')\n",
    "    input_range = ['1', '2']\n",
    "    #conflabel_range = ['TopSecret', 'Secret', 'Confidential', 'Unclassified']\n",
    "    #intlabel_range = ['VeryTrusted', 'Trusted', 'Slightly Trusted', 'UnTrusted']\n",
    "    while True:\n",
    "        username = input('plase enter the username which you want to grant access :')\n",
    "        if filename.count(' ') == 0 and filename.count('\\\\') == 0:\n",
    "            break\n",
    "        else:\n",
    "            print('username can not contain space or backslash.')\n",
    "    os.system('cls')\n",
    "    while True:\n",
    "        access_type = input('Please choose among the following numbers :\\n1.write access\\n2.read access\\n')\n",
    "        if access_type in input_range:\n",
    "            break\n",
    "    os.system('cls')\n",
    "    if access_type == 1:\n",
    "        command = 'grant '+ filename +' ' + username + ' r'\n",
    "    else:\n",
    "        command = 'grant '+ filename +' ' + username + ' w'\n",
    "        \n",
    "    after_login(client_sock, key, command)\n",
    "    input('Press enter to continue...\\n')\n",
    "\n",
    "def log_out(client_sock, key):\n",
    "    command = 'logout'\n",
    "    after_login(client_sock, key, command)\n",
    "    \n",
    "\n",
    "def revoce(client_sock, key):\n",
    "\n",
    "    os.system('cls')\n",
    "    while True:\n",
    "        filename = input('Please enter the File name : ')\n",
    "        if filename.count(' ') == 0 and filename.count('\\\\') == 0:\n",
    "            break\n",
    "        else:\n",
    "            print('Filename can not contain space or backslash.')\n",
    "    os.system('cls')\n",
    "    input_range = ['1', '2']\n",
    "    #conflabel_range = ['TopSecret', 'Secret', 'Confidential', 'Unclassified']\n",
    "    #intlabel_range = ['VeryTrusted', 'Trusted', 'Slightly Trusted', 'UnTrusted']\n",
    "    while True:\n",
    "        username = input('plase enter the username which you want to grant access :')\n",
    "        if filename.count(' ') == 0 and filename.count('\\\\') == 0:\n",
    "            break\n",
    "        else:\n",
    "            print('username can not contain space or backslash.')\n",
    "    os.system('cls')\n",
    "    while True:\n",
    "        access_type = input('Please choose among the following numbers :\\n1.write access\\n2.read access\\n')\n",
    "        if access_type in input_range:\n",
    "            break\n",
    "    os.system('cls')\n",
    "    if access_type == 1:\n",
    "        command = 'revoce '+ filename +' ' + username + ' r'\n",
    "    else:\n",
    "        command = 'revoce '+ filename +' ' + username + ' w'\n",
    "        \n",
    "    after_login(client_sock, key, command)\n",
    "    input('Press enter to continue...\\n')\n",
    "\n",
    "\n",
    "def first_menu(client_sock, key):\n",
    "\n",
    "    option = '0'\n",
    "    while option != '3':\n",
    "        os.system('clear' or 'cls')\n",
    "        option = input('Please choose among the following numbers :\\n1.Register\\n2.Login\\n3.Exit\\n')\n",
    "        if option == '1':\n",
    "            return register(client_sock, key)\n",
    "        elif option == '2':\n",
    "            return login(client_sock, key)\n",
    "    return -1 #To exit the program\n",
    "\n",
    "\n",
    "def second_menu(client_sock, key):\n",
    "    \n",
    "    option = '0'\n",
    "    while option != '6':\n",
    "        os.system('cls')\n",
    "        option = input('Please choose among the following numbers :\\n1.Put a file\\n2.Get a file\\n'\n",
    "        '3.Read a file\\n4.Write in a file\\n5.List files\\n6.Log Out\\n7.Grant Access\\n8.Revoce Access\\n')\n",
    "        if option == '1':\n",
    "            put(client_sock, key)\n",
    "        elif option == '2':\n",
    "            get(client_sock, key)\n",
    "        elif option == '3':\n",
    "            read(client_sock, key)\n",
    "        elif option == '4':\n",
    "            write(client_sock, key)\n",
    "        elif option == '5':\n",
    "            list_files(client_sock, key) \n",
    "        elif option == '6':\n",
    "            log_out(client_sock, key)\n",
    "        elif option == '7':\n",
    "            grant(client_sock, key)\n",
    "        elif option == '8':\n",
    "            revoce(client_sock, key)\n",
    "\n",
    "\n",
    "def random_captcha():\n",
    "\n",
    "    img = ImageCaptcha()\n",
    "    content = ''.join(random.choice(string.ascii_lowercase + string.digits) for _ in range(4))\n",
    "    image = img.generate_image(content)\n",
    "    image.show()\n",
    "\n",
    "    if input('Please enter captcha and close the picture: ').lower() == content :\n",
    "        return 1\n",
    "    return 0\n",
    "        \n",
    "\n",
    "if __name__ == \"__main__\":\n",
    "    \n",
    "    client_sock = connection_setup()\n",
    "    key = key_exchange(client_sock)\n",
    "    input('Press enter to continue...\\n')\n",
    "    while client_sock != None and key != None:\n",
    "        while AouthCode == '0':\n",
    "            first_menu(client_sock, key)\n",
    "        while AouthCode != '0':\n",
    "            second_menu(client_sock, key)\n",
    "    client_sock.shutdown()\n",
    "    client_sock.close()\n",
    "    os.system('cls')\n",
    "    print('Goodbye...')\n",
    "    #X123_bbsara_1289VVV"
   ]
  },
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   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "\n",
    "### "
   ]
  }
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