cryptography_flutter 2.3.4

Makes 'package:cryptography' use platform APIs in Android, iOS, and Mac OS X. The package can make performance up to 100 times better.

Overview

This is a Flutter plugin that enables pub.dev/packages/cryptography to use native APIs of Android, iOS, and Mac OS X.

Maintained by terrier989. Licensed under the Apache License 2.0.

Trade-offs of using operating system APIs

Pros

• Compliant.
  • Operating system implementations of algorithms are often compliant with various compliance requirements (such as FIPS 140-2).
• Speed.
  • For some algorithms, operating system implementations are up to 100 times faster than pure Dart implementations.

Cons

• Easier to inspect
  • If someone reverse engineers you application, it may be easier to inspect operating system calls than pure Dart implementations provided by package:cryptography.

General behavior

The package is tested with cryptography_test.

This package contains two kinds of classes:

• Classes such as FlutterChacha20 use operating system APIs in Android / iOS / Mac OS X. If the operating system does not support the algorithm, the background implementation (such as BackgroundChacha20) or a pure Dart implementation (such as DartChacha20) when available.
• Classes such as BackgroundChacha20 move lengthy computations to a background isolate by using compute function in Flutter SDK.
• Both compute very small inputs in the same isolate if the overhead of message passing does not make sense. For example, if you encrypt a 16 byte message, the computation is done in the same isolate.
• Too large inputs are also computed in the same isolate (because you probably should not allocate a gigabyte cross-isolate message on a mobile phone).
• We also have a queue to prevent memory exhaustion that could happen if you send lots of requests concurrently.

Getting started

In pubspec.yaml:

dependencies:
  cryptography: ^2.8.1g
  cryptography_flutter: ^2.3.4

That's it!

For API documentation, read more at pub.dev/packages/cryptography.

Behavior by algorithm

AES-GCM

FlutterAesGcm is used in Android, iOS, and Mac OS X. Our benchmarks have shown up to ~50 times better performance than DartAesGcm (the pure Dart implementation).

BackgroundAesGcm is used in Windows and Linux for inputs that are large enough.

ChaCha20-Poly1305-AEAD

FlutterChacha20 is available for Android and Apple operating systems. Our benchmarks have shown up to ~50 times better performance than DartChacha20 (the pure Dart implementation).

BackgroundChacha20 is used in Windows and Linux for inputs that are large enough.

NIST ECDH / ECDSA

FlutterEcdh and FlutterEcdsa are available for Apple operating systems.

Ed25519

FlutterEd25519 and BackgroundEd25519 are available for Apple operating systems.

X25519

FlutterX25519 and BackgroundX25519 are available for Apple operating systems.

HMAC

FlutterHmac is available for Android..

PBKDF2

FlutterPbkdf2 is available for Android. BackgroundPbkdf2 is used in Apple operating systems, Windows and Linux.

Links

• Github project
• Issue tracker
• Pub package
• API reference