c# RijndaelManaged encryption &解密有时会失败

编辑:solved -问题是解密功能。修正后的解密函数可以在下面的答案中找到。

我花了最后一天的时间在工作中试图找出我在AES的实现中出错的地方。我们需要能够加密/解密大文件，所以我使用文件流并将每个块写入磁盘。AES是一项要求，因为这需要与使用AES/CBC/pkcs5填充(据我所知相当于PKCS7/CBC)的java编写的现有系统一起工作

此实现适用于大多数文件。然而，有一些文件的最后5个字节的原始数据丢失。该文件将无错误地解密，但是哈希不匹配，丢失的字节是实际数据和末尾零的组合。

需要注意的是，这些流是在加密前后压缩的(代码在底部)。

    public static void AesEncrypt(byte[] keyBytes, byte[] ivBytes, Stream dataStream, FileStream outStream)
    {
        RijndaelManaged symmetricKey = new RijndaelManaged();
        symmetricKey.Mode = CipherMode.CBC;
        symmetricKey.Padding = PaddingMode.PKCS7;
        symmetricKey.BlockSize = 128;
        symmetricKey.KeySize = 256;
        const int chunkSize = 4096;//1024 * 1024 * 10;
        using (ICryptoTransform encryptor = symmetricKey.CreateEncryptor(keyBytes, ivBytes))
        {
            using (CryptoStream cryptoStream = new CryptoStream(outStream, encryptor, CryptoStreamMode.Write))
            {
                while (dataStream.Position != dataStream.Length)
                {
                    long remainingBytes = dataStream.Length - dataStream.Position;
                    var buffer = chunkSize > remainingBytes ? new byte[(int)remainingBytes] : new byte[chunkSize];
                    dataStream.Read(buffer, 0, buffer.Length);
                    cryptoStream.Write(buffer, 0, buffer.Length);
                    cryptoStream.Flush();
                }
                cryptoStream.FlushFinalBlock();
            }
        }
        symmetricKey.Clear();
    }

解密

    public static void AesDecrypt(byte[] keyBytes, byte[] ivBytes, Stream dataStream, FileStream outStream)
    {
        RijndaelManaged symmetricKey = new RijndaelManaged();
        symmetricKey.Mode = CipherMode.CBC;
        symmetricKey.Padding = PaddingMode.PKCS7;
        symmetricKey.BlockSize = 128;
        symmetricKey.KeySize = keyBytes.Length == 32 ? 256 : 128;
        const int chunkSize = 4096;
        using (ICryptoTransform decryptor = symmetricKey.CreateDecryptor(keyBytes, ivBytes))
        {
            using (CryptoStream cryptoStream = new CryptoStream(dataStream, decryptor, CryptoStreamMode.Read))
            {
                while (dataStream.Position != dataStream.Length)
                {
                    long remainingBytes = dataStream.Length - dataStream.Position;
                    var buffer = chunkSize > remainingBytes
                        ? new byte[(int) remainingBytes]
                        : new byte[chunkSize];
                    cryptoStream.Read(buffer, 0, buffer.Length);
                    outStream.Write(buffer, 0, buffer.Length);
                    outStream.Flush();
                }
                //cryptoStream.FlushFinalBlock(); // Was throwing an exception
            }
        }
        symmetricKey.Clear();
    }

压缩(加密前)

    public static void StreamCompress(Stream dataStream, FileStream outStream)
    {
        dataStream.Position = 0;
        outStream.Position = 0;
        const int chunkSize = 4096;
        using (GZipStream gzs = new GZipStream(outStream, CompressionMode.Compress))
        {
            while (dataStream.Position != dataStream.Length)
            {
                long remainingBytes = dataStream.Length - dataStream.Position;
                var buffer = chunkSize > remainingBytes ? new byte[(int)remainingBytes] : new byte[chunkSize];
                dataStream.Read(buffer, 0, buffer.Length);
                gzs.Write(buffer, 0, buffer.Length);
                gzs.Flush();
            }
        }
    }

解压(解密后)

    public static void StreamDecompress(Stream dataStream, FileStream outStream)
    {
        byte[] buffer = new byte[4096];
        dataStream.Position = 0;
        using (GZipStream gzs = new GZipStream(dataStream, CompressionMode.Decompress))
        {
            for (int r = -1; r != 0; r = gzs.Read(buffer, 0, buffer.Length))
                if (r > 0) outStream.Write(buffer, 0, r);
        }
}

我已经通过了一些其他的问题，但不能弄清楚为什么这只发生在一些文件。失败的文件大小为46,854,144字节。这似乎可以很好地处理大小文件。

任何帮助都将非常感激。

    public static void AesDecrypt(byte[] keyBytes, byte[] ivBytes, Stream dataStream, FileStream outStream)
    {
        dataStream.Position = 0;
        outStream.Position = 0;
        RijndaelManaged symmetricKey = new RijndaelManaged();
        symmetricKey.Mode = CipherMode.CBC;
        symmetricKey.Padding = PaddingMode.PKCS7;
        symmetricKey.BlockSize = 128;
        symmetricKey.KeySize = keyBytes.Length == 32 ? 256 : 128;
        const int chunkSize = 4096;
        using (ICryptoTransform decryptor = symmetricKey.CreateDecryptor(keyBytes, ivBytes))
        {
            using (CryptoStream cryptoStream = new CryptoStream(outStream, decryptor, CryptoStreamMode.Write))
            {
                while (dataStream.Position != dataStream.Length)
                {
                    long remainingBytes = dataStream.Length - dataStream.Position;
                    var buffer = chunkSize > remainingBytes
                        ? new byte[(int) remainingBytes]
                        : new byte[chunkSize];
                    var bytesRead = dataStream.Read(buffer, 0, buffer.Length);
                    cryptoStream.Write(buffer, 0, bytesRead);   
                }
                cryptoStream.FlushFinalBlock();
            }
        }
        symmetricKey.Clear();
    }