Cryptography class abstract

A factory for cryptographic algorithms.

This is used by factories in the cryptographic algorithm classes. For example, Chacha20.poly1305Aead calls the Cryptography.instance method chacha20Poly1305Aead.

Implementations

• DartCryptography
• BrowserCryptography
• FlutterCryptography (package:cryptography_flutter)

Setting implementation

In shipped application, it's a good practice to freeze the value of static variable with freezeInstance:

import 'package:cryptography/cryptography.dart';

void main() {
  Cryptography.freezeInstance(yourInstance);

  // ...
}

Writing you own subclass

import 'package:cryptography/browser.dart';
import 'package:cryptography/cryptography.dart';

class MyCryptography extends BrowserCryptography {
  @override
  Sha256 get sha256 {
    return SomeOtherSha256Implementation();
  }
}

void main() {
  // Change the default cryptography
  Cryptography.freezeInstance(MyCryptography());

  final sha256 = Sha256(); // --> SomeOtherSha256Implementation
}