Flutter数据处理与分析插件at_chops的使用

特性

• 使用RSA进行非对称公钥/私钥加密/解密
• 使用AES进行对称密钥加密/解密
• 用于PKAM认证的数据摘要签名和验证
• 用于at协议中公共数据的签名和验证
• 哈希操作

开始使用

• 开发者应该具备基本的非对称和对称加密知识。
• 开发者可以使用自己的密钥对/密钥，或者通过AtChopsUtil创建新的密钥对/密钥。

使用示例

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

import 'package:at_chops/at_chops.dart';
import 'package:at_chops/src/algorithm/at_algorithm.dart';
import 'package:encrypt/encrypt.dart';

/// 使用新生成的密钥对
/// dart run at_chops_example.dart
/// 或者
/// 使用来自atKeys文件的密钥对
/// dart run at_chops_example.dart <path_to_atkeys_file>
void main(List<String> args) async {
  AtChops atChops;

  if (args.isNotEmpty) {
    var atKeysFilePath = args[0];
    if (!File(atKeysFilePath).existsSync()) {
      throw Exception('\n无法找到.atKeys文件: $atKeysFilePath');
    }
    String atAuthData = await File(atKeysFilePath).readAsString();
    Map<String, String> atKeysDataMap = {};
    json.decode(atAuthData).forEach((String key, dynamic value) {
      atKeysDataMap[key] = value.toString();
    });
    atChops = _createAtChops(atKeysDataMap);
  } else {
    final atEncryptionKeyPair = AtChopsUtil.generateAtEncryptionKeyPair(); // 使用您的自己的加密密钥对
    final atPkamKeyPair = AtChopsUtil.generateAtPkamKeyPair(); // 使用您的自己的签名密钥对
    // 使用加密和pkam密钥对创建AtChopsKeys实例
    final atChopsKeys = AtChopsKeys.create(atEncryptionKeyPair, atPkamKeyPair);
    // 创建AtChopsImpl实例
    atChops = AtChopsImpl(atChopsKeys);
  }

  var atEncryptionKeyPair = atChops.atChopsKeys.atEncryptionKeyPair;
  
  // 1 - 使用非对称密钥对进行加密和解密
  final data = 'Hello World';
  // 1.1 使用[atEncryptionKeyPair.publicKey]加密数据
  final encryptionResult = atChops.encryptString(data, EncryptionKeyType.rsa2048);

  // 1.2 使用[atEncryptionKeyPair.privateKey]解密数据
  final decryptionResult = atChops.decryptString(encryptionResult.result, EncryptionKeyType.rsa2048);
  assert(data == decryptionResult.result, true);

  // 2 - 使用非对称密钥对进行签名和数据验证
  // 使用sign()和verify()
  final dataToSign = 'sample data';
  // 2.1 创建签名输入并设置签名和哈希算法类型
  AtSigningInput signingInput = AtSigningInput(dataToSign);
  signingInput.signingAlgoType = SigningAlgoType.rsa2048;
  signingInput.hashingAlgoType = HashingAlgoType.sha512;
  AtSigningAlgorithm signingAlgorithm = DefaultSigningAlgo(atEncryptionKeyPair, signingInput.hashingAlgoType);
  signingInput.signingAlgorithm = signingAlgorithm;
  // 2.2 签名数据
  final dataSigningResult = atChops.sign(signingInput);

  // 2.3 创建验证输入并设置签名和哈希算法类型
  AtSigningVerificationInput verificationInput = AtSigningVerificationInput(
      dataToSign,
      base64Decode(dataSigningResult.result),
      atEncryptionKeyPair!.atPublicKey.publicKey);
  verificationInput.signingAlgoType = SigningAlgoType.rsa2048;
  verificationInput.hashingAlgoType = HashingAlgoType.sha512;
  AtSigningAlgorithm verifyAlgorithm = DefaultSigningAlgo(atEncryptionKeyPair, verificationInput.hashingAlgoType);
  verificationInput.signingAlgorithm = verifyAlgorithm;
  // 2.4 验证签名
  AtSigningResult dataVerificationResult = atChops.verify(verificationInput);
  print('签名结果: ${dataVerificationResult.result}');
  assert(dataVerificationResult.result, true);
}

AtChops _createAtChops(Map<String, String> atKeysDataMap) {
  final atEncryptionKeyPair = AtEncryptionKeyPair.create(
      _decryptValue(atKeysDataMap[AuthKeyType.encryptionPublicKey]!, atKeysDataMap[AuthKeyType.selfEncryptionKey]!)!,
      _decryptValue(atKeysDataMap[AuthKeyType.encryptionPrivateKey]!, atKeysDataMap[AuthKeyType.selfEncryptionKey]!)!);
  final atPkamKeyPair = AtPkamKeyPair.create(
      _decryptValue(atKeysDataMap[AuthKeyType.pkamPublicKey]!, atKeysDataMap[AuthKeyType.selfEncryptionKey]!)!,
      _decryptValue(atKeysDataMap[AuthKeyType.pkamPrivateKey]!, atKeysDataMap[AuthKeyType.selfEncryptionKey]!)!);
  final atChopsKeys = AtChopsKeys.create(atEncryptionKeyPair, atPkamKeyPair);
  return AtChopsImpl(atChopsKeys);
}

class AuthKeyType {
  static const String pkamPublicKey = 'aesPkamPublicKey';
  static const String pkamPrivateKey = 'aesPkamPrivateKey';
  static const String encryptionPublicKey = 'aesEncryptPublicKey';
  static const String encryptionPrivateKey = 'aesEncryptPrivateKey';
  static const String selfEncryptionKey = 'selfEncryptionKey';
}

String? _decryptValue(String encryptedValue, String decryptionKey, {String? ivBase64}) {
  try {
    var aesKey = AES(Key.fromBase64(decryptionKey));
    var decrypter = Encrypter(aesKey);
    return decrypter.decrypt64(encryptedValue, iv: getIV(ivBase64));
  } on Exception catch (e, trace) {
    print(trace);
  } on Error catch (e) {
    print(e);
  }
  return null;
}

IV getIV(String? ivBase64) {
  if (ivBase64 == null) {
    // 从坏旧的日子，当时我们没有设置IV
    return IV(Uint8List(16));
  } else {
    return IV.fromBase64(ivBase64);
  }
}