Easy PBKDF2 for node.js

Easy PBKDF2 makes it easier to create secure, individually salted, password hashes using PBKDF2.

This implementation is based on StackExchange's own Open Sourced PBKDF2 methods.

Installation:

via cmd line:

$ npm install easy-pbkdf2 --save

or in your package.json:

"dependencies": {
    "easy-pbkdf2": "0.x.x"
}

Usage:

var easyPbkdf2 = require("easy-pbkdf2")();
var salt = easyPbkdf2.generateSalt(); // `salt` should be treated as opaque, as it captures iterations
var password = "RandomDigits";
easyPbkdf2.secureHash( password, salt, function( err, passwordHash, originalSalt ) {
    // use your own db's methods to save the hashed password AND salt.
    currentUser.update({
        // The Base64 encoded hash, 344 characters long
        "password_hash": passwordHash,
        // Salt length varies based on SALT_SIZE and iterations. The default SALT_SIZE of
        // 32 produces a value that is:
        // (hashIterations.toString(16).length) + 1 + base64EncodedSalt.length)
        // characters long (42 characters).
        "salt": originalSalt // === salt
    });
});

// ...

// sometime later:
function authenticate( user, userEnteredPassword, callback ) {
	// make sure the user-entered password is equal to the previously
    // created hash when hashed with the same salt.
    easyPbkdf2.verify( user.salt, user.password_hash, userEnteredPassword, function( err, valid ) {
        callback( valid );
    });
}

You can also use EasyPbkdf2 to generate the salt for you by omitting the salt parameter:

easyPbkdf2.secureHash( password, function( err, passwordHash, newSalt ) {
    // save newSalt somewhere!
});

To create a new instance of EasyPbkdf2:

    var easyPbkdf2 = require("easy-pbkdf2")();

You can also use the following methods of instantiation:

// the EasyPbkdf2 constructor
var EasyPbkdf2 = require("easy-pbkdf2"),
    easyPbkdf2;

easyPbkdf2 = EasyPbkdf2(options);
easyPbkdf2 = new EasyPbkdf2(options);
easyPbkdf2 = EasyPbkdf2.EasyPbkdf2(options);
easyPbkdf2 = new EasyPbkdf2.EasyPbkdf2(options);

of which all will return an EasyPbkdf2 instance with options set.

Options

 var options = {
    // default DEFAULT_HASH_ITERATIONS is 512
    "DEFAULT_HASH_ITERATIONS": 256,
    // default SALT_SIZE is 32
    "SALT_SIZE": 16,
    // default KEY_LENGTH is 256
    "KEY_LENGTH": 128,
    // default MAX_PASSWORD_LENGTH is 4096 characters
    "MAX_PASSWORD_LENGTH": 2048
};

var easyPbkdf2 = new EasyPbkdf2(options);
console.log(easyPbkdf2.DEFAULT_HASH_ITERATIONS) // 256
console.log(easyPbkdf2.SALT_SIZE); // 16
console.log(easyPbkdf2.KEY_LENGTH); // 128
console.log(easyPbkdf2.MAX_PASSWORD_LENGTH); // 2048

// options are applied to each instance individually.
console.log( (new EasyPbkdf2()).DEFAULT_HASH_ITERATIONS ); // 512

Methods

###weakHash( value )

Cranks out a collision resistant hash, relatively quickly. Not suitable for passwords, or sensitive information. Synchronous only

Params:

• value: String or Object. Base64 encoded SHA-1 hash of value

Returns:

• A string; Base64 encoded SHA-1 hash of value

---

###random( bytes, callback )

Universal random provider. Generates cryptographically strong pseudo-random data. Syncronous or Asyncronous

Params:

• bytes: Number. The number of bytes to return.
• callback: Function. The callback to call for async operation (optional)

Returns:

• A SlowBuffer; A buffer containing therandom bytes. (optional)

---

###generateSalt( explicitIterations, callback )

Convenience wrapper around .random to grab a new salt value. Treat this value as opaque, as it captures iterations.

Salt length varies based on SALT_SIZE and iterations. The default SALT_SIZE of 32 produces a value that is: (hashIterations.toString(16).length) + 1 + base64EncodedSalt.length) characters long (42 characters).

Synchronous or Asynchronous

Params:

• explicitIterations: Number. An integer (optional)
• callback: Function. (optional)

Returns:

• A String. Return iterations and salt together as one string ({hex-iterations}.{base64-salt}) (optional)

---

###secureHash( value, salt, callback )

Alias for hash.

---

###hash( value, salt, callback )

Backs Secure hashes. Uses PBKDF2 internally, as implemented by node's native crypto library. See http://en.wikipedia.org/wiki/PBKDF2 and http://code.google.com/p/crypto-js/ for more information. Asynchronous only

Params:

• value: String. The plaintext value/password you want to hash.
• salt: String. salt (should include iterations). Automatically created if omitted. (optional)
• callback: Function. fn( {Error} err, {String} A secure hash (base64 encoded), {String} the original or newly created salt ).

###verify( salt, priorHash, value, callback )

Verifies that the supplied plaintext value hashes to the same base64 encoded string as the priorHash, when hashed with the same salt. This method uses a constant-time string equality check to ensure information is not leaked via timing-attack. Asynchronous only

Params:

• salt: String. salt (should include iterations).
• priorHash: String. A secure hash (base64 encoded).
• value: String. The plaintext value/password you want to verify.
• callback: Function. fn( {Error} err, {Boolean} True if the value matches the priorHash, false if not. ).

Issues

Please file them here: https://github.com/davidmurdoch/easy-pbkdf2/issues.

And remember: pull requests are very welcome. :-)