Cryptography

The crypto module is mostly useful as a tool for implementing cryptographic protocols such as TLS and https.

Nodejs offers great support for cryptography.

The crypto module is a wrapper above the OpenSSL cryptographic functions. (HMAC, Cyphers, ...)

require("crypto")
  .createHash("md5")
  .update("This is some crypt string in node!")
  .digest("hex");

Thecryptomodule provides cryptographic functionality that includes a set of wrappers for OpenSSL's hash, HMAC, cipher, decipher, sign and verify functions.

How to determine if crypto support is unavailable

let crypto;

try {

crypto = require('crypto');

} catch (err) {

console.log('crypto support is disabled!');

}

Thecryptomodule provides theCertificateclass for working with SPKAC data.

Instances of theCertificateclass can be created using thenewkeyword or by callingcrypto.Certificate()as a function:

Example on hot to decrypt/encrypt text using the crypto module

var crypto = require('crypto'),
    algorithm = 'aes-256-ctr',
    password = 'd6F3Efeq';

function encrypt(text){
  var cipher = crypto.createCipher(algorithm,password)
  var crypted = cipher.update(text,'utf8','hex')
  crypted += cipher.final('hex');
  return crypted;
}

function decrypt(text){
  var decipher = crypto.createDecipher(algorithm,password)
  var dec = decipher.update(text,'hex','utf8')
  dec += decipher.final('utf8');
  return dec;
}

var hw = encrypt("hello world")

console.log(decrypt(hw));

An example on how to decrypt/encrypt buffers:

var crypto = require('crypto'),
    algorithm = 'aes-256-ctr',
    password = 'd6F3Efeq';

function encrypt(buffer){
  var cipher = crypto.createCipher(algorithm,password)
  var crypted = Buffer.concat([cipher.update(buffer),cipher.final()]);
  return crypted;
}

function decrypt(buffer){
  var decipher = crypto.createDecipher(algorithm,password)
  var dec = Buffer.concat([decipher.update(buffer) , decipher.final()]);
  return dec;
}

var hw = encrypt(new Buffer("hello world", "utf8"))
// outputs hello world
console.log(decrypt(hw).toString('utf8'));