如何从 AES 解密超过 16 个字节的字节 []

Question

所以我有一个长度为 1622 字节的 byte[]，但我想全部解密，但 AES 只有 128 位的块大小。 如果我试图将它分成 16 个字节的块，我会得到这个异常： System.Security.Cryptography.CryptographicException 附加信息：输入缓冲区包含的数据不足。可能是 rawDataArea % 16 != 0？

加密器：

        aes256Alg = new AesManaged
        {
            Key = new byte[] {112,90,16,164,90,221,73,154,246,32,13,102,145,7,57,115,37,5,3,102,205,39,202,231,195,148,202,229,53,138,102,242},
            Mode = CipherMode.CBC,
            KeySize = 256,
            BlockSize = 128,
            Padding = PaddingMode.PKCS7,
            IV = new byte[] {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}
        };
        ICryptoTransform aes256Encryptor = aes256Alg.CreateEncryptor(aes256Alg.Key,aes256Alg.IV);

---

解密器

        AesManaged aes256AlgCBC;
        aes256AlgCBC = new AesManaged
        {
            Key = new byte[] {190,151,28,108,241,101,254,174,16,11,87,84,239,140,239,85,195,25,78,192,105,109,95,128,160,146,123,31,190,188,181,216},
            KeySize = 256,
            Mode = CipherMode.CBC,
            BlockSize = 128,
            Padding = PaddingMode.PKCS7,
            IV = new byte[] {199,114,91,241,148,90,133,166,13,52,142,187,101,125,81,73}
        };
        ICryptoTransform aes256CbcDecryptor = aes256AlgCBC.CreateDecryptor(aes256AlgCBC.Key, aes256AlgCBC.IV);



        //byte[] rawDataArea = {0x00 .......} // Length of 1622 copied from hexeditor

        List<Byte[]> dataAreaByteList = new List<byte[]>();
       //Split the rawDataArea up to blocks of 16 bytes and then adding them to a list 
       //which later can be converted back to a big array

       for (int i = 0; i < rawDataArea.Length; i += 16)
       {
             byte[] transformedBlock = new byte[] { };
             aes128CbcDecryptor.TransformBlock(rawDataArea, i, (i += 16),transformedBlock,i);
             dataAreaByteList.Add(transformedBlock);
        }

Answer 1

您在每次循环迭代中执行两次i += 16。无论如何，您不需要转换为 16 字节块。使用CryptoStream 并写入您喜欢的任意大小，例如 4KB。大多数教程都是这样做的。也许你发现了一个糟糕的教程。