chat-client/index.js

// Get some libraries
const net = require("net");
const node_rsa = require("node-rsa");
const bsplit = require("buffer-split");

// Load the settings
var settings = require("./settings.json");

// Encryption varibles
var encryption;
var rsa_key;

// Create a client
var client = new net.Socket();

function string_decrypt(key, string)
{
  // Convert the string to a buffer
  var buff = new Buffer.from(string);

  // Create some new data
  var decrypted = new Buffer.alloc(buff.length);

  // Iterate over the string
  for(var i=0;i<string.length;i++)
  {
    // Convert the string item to a number
    var d = buff[i]-key.str[key.at.rx];
    while(d < 0) d += 256;
    decrypted[i] = d;

    // Add 1 to the key counter
    key.at.rx += 1;

    // Is the key counter out of range
    if(key.at.rx >= key.str.length)
    {
      // Set to zero
      key.at.rx = 0;
    }
  }

  // Return the encrypted data
  return decrypted;
}

function string_encrypt(key, string)
{
  // Convert the string to a buffer
  var buff = new Buffer.from(string);

  // Create some new data
  var encrypted = new Buffer.alloc(buff.length);

  // Iterate over the string
  for(var i=0;i<string.length;i++)
  {
    // Convert the string item to a number
    var e = buff[i]+key.str[key.at.tx];
    while(e > 255) e -= 256;
    encrypted[i] = e;

    // Add 1 to the key counter
    key.at.tx += 1;

    // Is the key counter out of range
    if(key.at.tx >= key.str.length)
    {
      // Set to zero
      key.at.tx = 0;
    }
  }

  // Return the encrypted data
  return encrypted;
}

function make_encryption_key(string)
{
  // Make a new key
  var key = new Object();

  // Set the varibles
  key.str = string;
  key.at = new Object();
  key.at.rx = 0;
  key.at.tx = 0;

  // Return the key
  return key;
}

function socket_write(socket, encryption, data)
{
  // Send the data encrypted with JSON
  socket.write(string_encrypt(encryption, JSON.stringify(data)+"\n"));
}

function socket_ondata(socket, callback)
{
  // Wait for a response
  socket.on('data', function(data)
  {
    // Decode the data
    data = JSON.parse(data);

    // Call the callback
    callback(data);
  });
}

// Connect to the server
client.connect(22068, '127.0.0.1', function()
{
  // Create an rsa key
  rsa_key = new node_rsa({b:settings.rsa_size});

  // Send the public key to the server
  client.write(rsa_key.exportKey("public"));
});

// Set new
var sock_new = 2;

// Set a temporary encryption varible
var raw_encryption_data = "";
var raw_encryption_data_upto = 0;
var raw_encryption_data_size = 0;

// Wait for data
client.on('data', function(data)
{
  if(sock_new == 2)
  {
    console.log("Recieved key.");

    // Set the size of the key
    raw_encryption_data_size = parseInt(data);

    // Set sock new to 1
    sock_new = 1;
  }

  // Is the socket recieving the key
  else if(sock_new == 1)
  {
    console.log(data);

    // Decode the data
    raw_encryption_data += data;
    raw_encryption_data_upto += data.length;
    console.log(data.length);

    // Is this the end of the stream
    if(raw_encryption_data_upto == raw_encryption_data_size)
    {
      // Set sock new to 0
      sock_new = 0;

      // Set the key
      encryption = make_encryption_key(rsa_key.decrypt(raw_encryption_data));

      console.log("Done.");

      socket_write(client, encryption, {message: "hello, world!", number: 53});
    }
  }

  else
  {
    // Decrypt the data
    data = string_decrypt(encryption, data);

    // Split the data by newlines
    data = bsplit(data, Buffer.from("\n"));

    // Iterate over them
    for(var i=0;i<data.length-1;i++)
    {
      console.log(JSON.parse(data[i]));
    }
  }
});

client.on('close', function(data)
{
  // Close the window
  //window.close();
});