NodeJS - CRYPTO : Symmetric Cryptography of Files

nodeJs.crypto.simmetricCryptographyOfFiles.js

var crypto     = require('crypto')
  , fs         = require('fs')

var sourceFile = __dirname + "/testFile.txt"
  , targetFile = __dirname + "/testEncryptedFile.txt"
  , key        = "SecretKey"
  , algorithm  = 'aes192' // Another algorithms: 'des-ede3-cbc'
  , cipher     = crypto.createCipher(algorithm, key)
  , decipher   = crypto.createDecipher(algorithm, key)
  , rs         = fs.ReadStream(sourceFile)
  , ws         = fs.WriteStream(targetFile)

// Encrypting a File
var fileContent = ''
var cryptedFileContent
rs.on('data', function(data) {
	fileContent += data
  cryptedFileContent = cipher.update(data, 'utf8', 'hex')
  ws.write(cryptedFileContent)
})

rs.on('end', function() {
  var finalStream = cipher.final('hex')
  // After use final method you can not use cipher again

  cryptedFileContent+= finalStream
  ws.write(finalStream, function(){
	  console.log("\nEncrypt a File: " + sourceFile)
	  console.log("Target File:    " + targetFile + "\nContent: " + fileContent)
	  console.log("Encrypted File Content : " + cryptedFileContent)
	  var cryptedTargetFileContent = fs.readFileSync(targetFile)
	  console.log("Target File Content :    " + cryptedTargetFileContent)
  })
})

// NOTE: To decrypt use decipher object of similar way