Affinidi TDK - Cryptography

affinidi_tdk_cryptography is a library that provides encryption and decryption utilities for the Affinidi TDK, allowing developers to perform secure cryptographic operations in Dart applications.

💡NOTE: In most cases there is no need to use this package directly and instead use a higher level package or library, like affinidi_tdk_consumer_auth_provider or affinidi_tdk_auth_provider.

Table of Contents

Requirements

  • Dart SDK version ^3.6.0

Getting Started

Add the following to your pubspec.yaml file:

dependencies:
  affinidi_tdk_cryptography: ^<version_number>

Then run:

dart pub get

Usage

Here is an example of how to use the cryptographic utilities:

import 'dart:convert';
import 'dart:typed_data';

import 'package:affinidi_tdk_cryptography/affinidi_tdk_cryptography.dart';

Future<void> main() async {
  const salt = 'fixed_salt';

  // Encryption
  final cryptographyService = CryptographyService();
  final Uint8List passwordBytes = readPasswordBytes();
  late final List<int> passwordEncryptionKey;
  try {
    passwordEncryptionKey = await cryptographyService.pbkdf2FromBytes(
      passwordBytes: passwordBytes,
      nonce: utf8.encode(salt),
    );
  } finally {
    passwordBytes.fillRange(0, passwordBytes.length, 0);
  }
  final encryptionKey = cryptographyService.getRandomBytes(32);
  final encryptedPassword = await cryptographyService.Aes256Encrypt(
    key: encryptionKey,
    data: passwordEncryptionKey,
  );

  ...

  // Decryption
  final decryptedPasswordBytes = await cryptographyService.Aes256Decrypt(
    encryptedData: encryptedPassword,
    key: encryptionKey,
  );
  if (decryptedPasswordBytes == null) {
    throw Exception('Failed to decrypt password');
  }
}

Libraries

affinidi_tdk_cryptography