AES 加密和输入字符串编码

Question

有人可以解释一下为什么这两段代码没有给出相同的结果，而第二个示例中的 StreamWriter 使用的是 UTF8 编码：var TokenEncryptKey = "D268197CF891452844441A143AAEAAEB";        var key = Encoding.UTF8.GetBytes(TokenEncryptKey);        var alg = new RijndaelManaged();        alg.Key = key;        alg.Mode = CipherMode.ECB;        var mem = new MemoryStream();        CryptoStream encryptStream = new CryptoStream(mem, alg.CreateEncryptor(), CryptoStreamMode.Write);        var validReservation = Encoding.UTF8.GetBytes("AAAAAAAAAAAAAAAAAAAAAAA");        encryptStream.Write(validReservation, 0, validReservation.Length);        encryptStream.Flush();        encryptStream.FlushFinalBlock();        Console.Out.WriteLine(Convert.ToBase64String(mem.GetBuffer(), 0, (int)mem.Length));第二个例子var TokenEncryptKey = "D268197CF891452844441A143AAEAAEB";        var key = Encoding.UTF8.GetBytes(TokenEncryptKey);        var alg = new RijndaelManaged();        alg.Key = key;        alg.Mode = CipherMode.ECB;        var mem = new MemoryStream();        CryptoStream encryptStream = new CryptoStream(mem, alg.CreateEncryptor(), CryptoStreamMode.Write);        StreamWriter sw = new StreamWriter(encryptStream, Encoding.UTF8);        sw.Write("AAAAAAAAAAAAAAAAAAAAAAA");        sw.Flush();        encryptStream.FlushFinalBlock();        Console.Out.WriteLine(Convert.ToBase64String(mem.GetBuffer(), 0, (int)mem.Length));

Answer 1

当您使用 时StreamWriter(encryptStream, Encoding.UTF8)，这将添加 3 个字节的 Unicode BOM（字节顺序标记）。为避免这种情况，请new StreamWriter(m, new UTF8Encoding())改用。

Encoding.UTF8.GetBytes即使设置了编码来执行此操作，也不会添加 BOM - 如果需要，您可以使用它来检索它GetPreamble。