如何在Dart中实现与C# Rijndael一致的Key和IV加密逻辑？

我有一个C#的Rijndael加密函数，希望迁移至Dart环境。使用encrypt.dart包尝试实现后，无法得到与C#相同的加密结果。以下是相关代码及结果，请求帮助实现一致的加密输出：

C#核心加密代码 #

private RijndaelManaged myRijndael = new RijndaelManaged();
public ClsCrypto(string strPlainText)
{
string strIV = "$@A@B@_3CP$Y$T2M";

myRijndael.IV = Encoding.UTF8.GetBytes(strIV);
myRijndael.Key = Encoding.UTF8.GetBytes("$@J@Y@3NT3RPRI$3R3$OURC3PL@NNING");
byte[] originalBytes = new System.Text.UTF8Encoding().GetBytes(strPlainText);

ICryptoTransform transform = myRijndael.CreateEncryptor();
byte[] encryptedText = transform.TransformFinalBlock(originalBytes, 0, originalBytes.Length);
return Convert.ToBase64String(encryptedText);
}

Dart初始尝试代码 #

final key = Key.fromUtf8("\$@J@Y@3NT3RPRI\$3R3\$OURC3PL@NNING");
final iv = IV.fromUtf8("\$@A@B@_3CP\$Y\$T2M");

final encrypter = Encrypter(AES(key));
final encrypted = encrypter.encrypt(plainText, iv: iv);

调整后的Dart代码及结果 #

String strIV = "\$@J@Y@_3RP\$Y\$T3M";
final plainText = 'CCCC-1111-CCCC-2222-CCCC-3333-CCCC';
final key = Key.fromUtf8(String.fromCharCodes(utf8.encode("\$@J@Y@3NT3RPRI\$3R3\$OURC3PL@NNING")));
final iv = IV.fromUtf8(String.fromCharCodes(utf8.encode(strIV)));

final encrypter = Encrypter(AES(key));
final encrypted = encrypter.encrypt(plainText, iv: iv);
print("encrypted : ${encrypted.base64}");

Dart加密结果：UwQqA5DjJ7xO3POMpmyQZxINEGDM9ImcEgrC5M8pF2hiFy4CkCrbY6QBdM7EbbuR

C#完整测试代码及结果 #

using System;
using System.Security.Cryptography;
using System.Text;
namespace ConsoleApp3
{

public class ClsCrypto
{ 
private RijndaelManaged myRijndael = new RijndaelManaged();

public static void Main(){
        ClsCrypto cs = new ClsCrypto("$@J@Y@_3RP$Y$T3M");
         cs.Encrypt("CCCC-1111-CCCC-2222-CCCC-3333-CCCC");
        }
public ClsCrypto(string strIV)
{
}
public void Encrypt(string strPlainText)
{
String strIV = "$@J@Y@_3RP$Y$T3M"; //Default IV
myRijndael.IV = Encoding.UTF8.GetBytes(strIV);
myRijndael.Key = Encoding.UTF8.GetBytes("$@J@Y@3NT3RPRI$3R3$OURC3PL@NNING");
byte[] originalBytes = new System.Text.UTF8Encoding().GetBytes(strPlainText);
ICryptoTransform transform = myRijndael.CreateEncryptor();
byte[] encryptedText = transform.TransformFinalBlock(originalBytes, 0, originalBytes.Length);
Console.WriteLine(Convert.ToBase64String(encryptedText));
}
}
}

C#加密结果：26CxCs5A7c7Sk5+0/hQ300vkHsCuRPXyACbrcRxyeCBWwAK9TCOLdkDHvBaLJXYH

问题原因及解决方案 #

核心差异点 #

C#的RijndaelManaged默认使用以下参数：

• 加密模式：CipherMode.CBC
• 填充方式：PaddingMode.PKCS7
• 密钥长度：256位（你的Key是32字节UTF8，刚好对应256位）
• IV长度：128位（你的IV是16字节UTF8，对应128位）

而encrypt.dart包的AES类默认参数与C#不一致，默认模式是AESMode.sic（CTR模式），填充方式也不是PKCS7，这是导致结果不一致的根本原因。

修正后的Dart代码 #

指定AES的模式为CBC，填充为PKCS7即可：

import 'package:encrypt/encrypt.dart';

void main() {
  final strIV = "\$@J@Y@_3RP\$Y\$T3M";
  final plainText = 'CCCC-1111-CCCC-2222-CCCC-3333-CCCC';
  final key = Key.fromUtf8("\$@J@Y@3NT3RPRI\$3R3\$OURC3PL@NNING");
  final iv = IV.fromUtf8(strIV);

  // 指定CBC模式和PKCS7填充，与C#默认参数对齐
  final encrypter = Encrypter(AES(
    key,
    mode: AESMode.cbc,
    padding: AESPadding.pkcs7,
  ));
  final encrypted = encrypter.encrypt(plainText, iv: iv);
  print("encrypted : ${encrypted.base64}");
}

运行这段代码后，输出的Base64结果将与C#版本完全一致：26CxCs5A7c7Sk5+0/hQ300vkHsCuRPXyACbrcRxyeCBWwAK9TCOLdkDHvBaLJXYH

内容的提问来源于stack exchange，提问作者Yazan