Flutter本地认证加密插件local_auth_crypto的使用

local_auth_crypto

在Android和iOS设备上通过生物识别允许本地认证+加密。

特性

新实例

final localAuthCrypto = LocalAuthCrypto.instance;

加密

await localAuthCrypto.encrypt(message);

PromptInfo

BiometricPromptInfo(
  title: 'BIOMETRIC',
  subtitle: 'Please scan biometric to decrypt',
  negativeButton: 'CANCEL',
);

解密

await localAuthCrypto.authenticate(promptInfo, cipherText);

开始使用

使用非常简单！你需要确保在你的Flutter项目中添加local_auth_crypto作为依赖项。

local_auth_crypto: "^1.1.1"

使用方法

Flutter

加密

final localAuthCrypto = localAuthCrypto.instance;

final message = 'TOKEN';
final cipherText = await localAuthCrypto.encrypt(message);

解密

final localAuthCrypto = localAuthCrypto.instance;

final promptInfo = BiometricPromptInfo(
  title: 'BIOMETRIC',
  subtitle: 'Please scan biometric to decrypt',
  negativeButton: 'CANCEL',
);
final plainText = await localAuthCrypto.authenticate(promptInfo, cipherText);

Android

更新代码在 MainActivity.kt 文件中

import io.flutter.embedding.android.FlutterFragmentActivity

class MainActivity : FlutterFragmentActivity()

在 AndroidManifest.xml 文件中添加权限

<uses-permission android:name="android.permission.USE_BIOMETRIC" />

iOS

在 info.plist 文件中添加隐私描述

<dict>
  <key>NSFaceIDUsageDescription</key>
  <string>This application wants to access your TouchID or FaceID</string>
</dict>

完整示例

以下是一个完整的示例，展示了如何使用local_auth_crypto进行加密和解密操作。

import 'package:flutter/material.dart';
import 'package:local_auth_crypto/local_auth_crypto.dart';

void main() {
  runApp(const MyApp());
}

class MyApp extends StatefulWidget {
  const MyApp({super.key});

  [@override](/user/override)
  State<MyApp> createState() => _MyAppState();
}

class _MyAppState extends State<MyApp> {
  final String _biometricToken = 'TOKEN FROM SERVER';
  String? _biometricTokenCipherText = '';
  String? _biometricTokenPlainText = '';
  final _localAuthCrypto = LocalAuthCrypto.instance;

  [@override](/user/override)
  void initState() {
    super.initState();
    _processEncrypt();
    _processCanEvaluatePolicy();
  }

  [@override](/user/override)
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: const Text('LOCAL AUTH PLUS'),
        ),
        body: SafeArea(
          child: SingleChildScrollView(
            child: Container(
              margin: const EdgeInsets.all(16),
              child: Column(
                crossAxisAlignment: CrossAxisAlignment.start,
                children: [
                  Text(
                    'TOKEN',
                    style: Theme.of(context).textTheme.titleLarge,
                  ),
                  const SizedBox(height: 8),
                  CardBox(content: _biometricToken),
                  const SizedBox(height: 16),
                  Text(
                    'CIPHER TEXT',
                    style: Theme.of(context).textTheme.titleLarge,
                  ),
                  const SizedBox(height: 8),
                  CardBox(content: _biometricTokenCipherText ?? ''),
                  const SizedBox(height: 16),
                  Text(
                    'PLAIN TEXT',
                    style: Theme.of(context).textTheme.titleLarge,
                  ),
                  const SizedBox(height: 8),
                  CardBox(content: _biometricTokenPlainText ?? ''),
                  const SizedBox(height: 46),
                  SizedBox(
                    width: double.infinity,
                    child: Column(
                      crossAxisAlignment: CrossAxisAlignment.center,
                      children: [
                        IconButton(
                          onPressed: () {
                            _processDecrypt();
                          },
                          icon: const Icon(Icons.fingerprint_outlined),
                          iconSize: 80,
                        ),
                        const Text('Decrypt by Biometric'),
                      ],
                    ),
                  ),
                ],
              ),
            ),
          ),
        ),
      ),
    );
  }

  void _processEncrypt() async {
    _biometricTokenCipherText = await _localAuthCrypto.encrypt(_biometricToken);
    setState(() {});
  }

  void _processDecrypt() async {
    final promptInfo = BiometricPromptInfo(
      title: 'BIOMETRIC',
      subtitle: 'Please scan biometric to decrypt',
      negativeButton: 'CANCEL',
    );
    _biometricTokenPlainText = await _localAuthCrypto.authenticate(
      promptInfo,
      _biometricTokenCipherText ?? '',
    );
    setState(() {});
  }

  void _processCanEvaluatePolicy() async {
    final status = await _localAuthCrypto
        .evaluatePolicy('Allow biometric to authenticate');
    print('status: $status');
  }
}

class CardBox extends StatelessWidget {
  final String content;

  const CardBox({Key? key, required this.content}) : super(key: key);

  [@override](/user/override)
  Widget build(BuildContext context) {
    return Container(
      width: double.infinity,
      decoration: BoxDecoration(
        color: Colors.grey.shade300,
        borderRadius: BorderRadius.circular(16),
      ),
      child: Padding(
        padding: const EdgeInsets.all(16.0),
        child: Text(content),
      ),
    );
  }
}