This module adds some protection against poison null bytes to the native "fs" module. To activate it, just put this at the top of your main application file:

require('protect-fs')

This modifies all relevant fs methods (I hope I didn't forget any) to give you this protection.

Installation

npm install protect-fs

Examples

> require('fs').readFileSync('/etc/passwd\0', 'utf8').length
2226
> require('fs').readFile('/etc/passwd\0', 'utf8', function(e,d){if(e){console.error('error cb');throw e;}console.log(d.length)})
> 2226

> require('protect-fs')
{}
> require('fs').readFileSync('/etc/passwd\0', 'utf8').length
Error: fs function was called with a nullbyte in argument #0
    at fail (/home/jann/tmp/node_modules/protect-fs/index.js:17:15)
    at Object.openSync (/home/jann/tmp/node_modules/protect-fs/index.js:28:16)
    at Object.readFileSync (fs.js:113:15)
    at repl:1:16
    at REPLServer.eval (repl.js:80:21)
    at Interface.<anonymous> (repl.js:182:12)
    at Interface.emit (events.js:67:17)
    at Interface._onLine (readline.js:162:10)
    at Interface._line (readline.js:426:8)
    at Interface._ttyWrite (readline.js:603:14)
> require('fs').readFile('/etc/passwd\0', 'utf8', function(e,d){if(e){console.error('error cb');throw e;}console.log(d.length)})
> error cb

node.js:202
        throw e; // process.nextTick error, or 'error' event on first tick
              ^
Error: fs function was called with a nullbyte in argument #0
    at fail (/home/jann/tmp/node_modules/protect-fs/index.js:17:15)
    at Object.open (/home/jann/tmp/node_modules/protect-fs/index.js:28:16)
    at new <anonymous> (fs.js:1019:6)
    at Object.createReadStream (fs.js:973:10)
    at Object.readFile (fs.js:71:23)
    at repl:1:16
    at REPLServer.eval (repl.js:80:21)
    at Interface.<anonymous> (repl.js:182:12)
    at Interface.emit (events.js:67:17)
    at Interface._onLine (readline.js:162:10)