Pbkdf2 class abstract

PBKDF2 password hashing algorithm implemented in pure Dart.

DartPbkdf2 is the pure Dart implementation of the PBKDF2 algorithm. It's used when no faster implementation is available.

In browsers, "package:cryptography" will automatically attempt to use Web Crypto API, which has very good PBKDF2 performance.

Flutter developers should add cryptography_flutter, as a dependency for the best possible PBKDF2 performance.

Things to know

• macAlgorithm can be any MacAlgorithm (such as Hmac.sha256()).
• iterations is the number of times output of hashing will be used as input of the next hashing iteration. The idea of password hashing algorithms is to make password hashing as slow as possible so the higher the better. A good value is usually at least 10 000.
• bits is the number of bits you want as output. A good value may be 256 bits (32 bytes).
• PBKDF2 is a popular choice for password hashing, but much better algorithms exists (such as Argon2id).

Example

import 'package:cryptography/cryptography.dart';

Future<void> main() async {
  final pbkdf2 = Pbkdf2(
    macAlgorithm: Hmac.sha256(),
    iterations: 10000, // 20k iterations
    bits: 256, // 256 bits = 32 bytes output
  );

  // Calculate a hash that can be stored in the database
  final newSecretKey = await pbkdf2.deriveKeyFromPassword(
    // Password given by the user.
    password: 'qwerty',

    // Nonce (also known as "salt") should be some random sequence of
    // bytes.
    //
    // You should have a different nonce for each user in the system
    // (which you store in the database along with the hash).
    // If you can't do that for some reason, choose a random value not
    // used by other applications.
    nonce: const [1,2,3],
  );

  final secretKeyBytes = await secretKey.extractBytes();
  print('Result: $secretKeyBytes');
}

Inheritance

• Object
• KdfAlgorithm
• Pbkdf2

Implementers

• DartPbkdf2

Constructors

Pbkdf2({required MacAlgorithm macAlgorithm, required int iterations, required int bits})

Constructs PBKDF2 with any MacAlgorithm.

factory

Pbkdf2.constructor()

Constructor for subclasses.

const

Pbkdf2.hmacSha256({required int iterations, required int bits})

Constructs PBKDF2 with Hmac.sha256.

factory

Properties

bits → int

Number of bits that will be returned by deriveKey method.

no setter

hashCode → int

The hash code for this object.

no setter, override

iterations → int

Number of iterations.

no setter

macAlgorithm → MacAlgorithm

MAC algorithm.

no setter

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

Methods

deriveKey({required SecretKey secretKey, required List<int> nonce}) → Future<SecretKey>

Generates a new secret key from a secret key and a nonce.

inherited

deriveKeyFromPassword({required String password, required List<int> nonce}) → Future<SecretKey>

Generates a new secret key from a password and a nonce.

inherited

noSuchMethod(Invocation invocation) → dynamic

Invoked when a nonexistent method or property is accessed.

inherited

toString() → String

A string representation of this object.

override

toSync() → DartPbkdf2

Returns a pure Dart implementation of PBKDF2 with the same parameters.

Operators

operator ==(Object other) → bool

The equality operator.

override