Secure distribution of NodeJS applications

Robin Rodricks picture Robin Rodricks · Feb 23, 2012 · Viewed 28.6k times · Source

What: Can NodeJS apps be distributed as binary? ie. you compile the .js app via V8 into its native binary, and distribute the binary to clients? (if you had total access to the NodeJS server)... or is minifying the code all you can do?

Why: We build serverside applications in NodeJS for clients, that have often to be hosted on the client's servers. Distributing source code means clients can easily steal our solution and stop paying licensing fees. This opens up the possibility of easy reverse-engineering or reuse of our apps without our awareness.

Answer

Thiago de Arruda picture Thiago de Arruda · Sep 28, 2012

Yes it is possible, use this branch(based on 0.8.18) and any js code you put in 'deps/v8/src/extra-snapshot.js' will be ahead-of-time compiled to machine code and embedded in v8 as part of the normal builtin object initialization. You will need to build nodejs for each platform you intend to deploy your product.

The snapshotted code runs very early in the v8 initialization and you cannot access builtin objects in the 'module body'. What you can do is put all your code inside a global initialization function to be called later. Ex:

// 'this' points to the same as the object referenced by 
// 'global' in normal nodejs code.
// at this point it has nothing defined in it, so in order to use
// global objects a reference to it is needed.
var global = this;
global.initialize = function() {
  // You have to define all global objects you use in your code here;
  var Array = global.Array;
  var RegExp = global.RegExp;
  var Date = global.Date;
  // See ECMAScript v5 standard global objects for more
  // Also define nodejs global objects:
  var console = global.console;
  var process = global.process;
  // Your code goes embedded here
};

Also, this assumes your entire code is defined in a single file, so if your project uses nodejs module system(require) you need to write a script that will combine all your files in one and wrap each file in a closure that will trick your code into thinking it is a normal nodejs module. Probably each module closure would expose a require function, and this function would have to decide when to delegate to the standard 'global.require' or return exports from your other embedded modules. See how javascript module systems are implemented for ideas(requirejs is a good example).

This will make your code harder to debug since you wont see stack traces for native code.

UPDATE:

Even using v8 snapshots the code gets embedded in the node.js binary because v8 prefers lazy compilation. See this for more information.