chainkey_android

Android platform implementation for the chainkey federated plugin.

This package provides native Android hardware security enclave integration using AndroidKeyStore, StrongBox KeyMint, and the Android BiometricPrompt API.

Features

  • Hardware Enclave Backing: Generates non-exportable NIST P-256 (secp256r1) private keys inside dedicated hardware (StrongBox HSM chip on supported devices, or ARM TrustZone TEE).
  • Biometric User Presence: Integrates with Android BiometricPrompt to enforce biometric or device passcode authentication prior to signing operations.
  • ERC-4337 & EIP-7212 Compliance: Produces ASN.1 DER signatures and automatically computes low-$S$ normalized scalar components (r, s) to prevent signature malleability.
  • Hardware Key Attestation: Supports Android Keystore X.509 attestation certificate chains embedding server challenge nonces.

Minimum Requirements

  • Android SDK (minSdk): 24 (Android 7.0 Nougat)
  • Compile SDK: 34+
  • JDK: 17

Usage

This package is endorsed by the main chainkey package. When adding chainkey to your pubspec.yaml, chainkey_android is automatically included and registered:

dependencies:
  chainkey: ^0.1.0

To invoke hardware isolation methods from Flutter:

import 'package:chainkey/chainkey.dart';

final supported = await Chainkey.instance.isHardwareIsolationSupported(
  HardwareIsolationLevel.strongBox,
);

Issues & Contributing

For bug reports, feature requests, and contributing guidelines, please visit the Chainkey GitHub Repository.

Libraries

chainkey_android