c#Rijndael管理的播种量比Java(AES / CFB8 / NoPadding)低10倍

时间:2019-02-17 01:03:14

标签: java c# aes rijndaelmanaged aescryptoserviceprovider

在调试C#应用程序的性能时,我注意到它比Java等效要慢得多。经过研究,问题似乎是由加密/解密方法引起的。

我被迫在模式设置为CFB8且没有填充的情况下使用AES加密。对于Java,这很简单,因为我可以使用Cipher.getInstance("AES/CFB8/NoPadding");。在C#中,我发现我需要使用new RijndaelManaged()。使用相同的键和相同的数据运行测试后,以下是结果

Java:

  • 加密:0.402秒
  • 解密:0.480秒

C#:

  • 加密:4.201秒
  • 解密:3.671秒

C#密码

    public ICryptoTransform enc;
    public ICryptoTransform dec;

    public AesCrypto(byte[] key)
    {
        enc = Generate(key).CreateEncryptor();
        dec = Generate(key).CreateDecryptor();
    }

    private SymmetricAlgorithm Generate(byte[] key) {
        RijndaelManaged cipher = new RijndaelManaged(); 
        cipher.Mode = CipherMode.CFB;
        cipher.Padding = PaddingMode.None;
        cipher.KeySize = 128;
        cipher.FeedbackSize = 8;
        cipher.Key = key;
        cipher.IV = key;
        return cipher;
    }

    public byte[] Crypt(byte[] buffer, int offset, int count) {
        return enc.TransformFinalBlock(buffer, offset, count); 
    }

C#测试代码:

 static void Test() {
        // Init
        var AesCrypto = new AesCrypto(Encoding.UTF8.GetBytes("aaabbbccaaabbbcc"));
        var testData = Encoding.UTF8.GetBytes(createDataSize(9000000)); // 9mb test.

        // Timer
        var stopWatch = new Stopwatch();
        stopWatch.Start();
        AesCrypto.Crypt(testData, 0, testData.Length);
        stopWatch.Stop();
        Console.WriteLine("AesCrypto.Crypt took: " + stopWatch.ElapsedMilliseconds);
 }
 static string createDataSize(int msgSize)
    {
        StringBuilder sb = new StringBuilder(msgSize);
        for (int i = 0; i < msgSize; i++)
        {
            sb.Append('a');
        }
        return sb.ToString();
    }

结果:“ AesCrypto.Crypt占用了:3626”

JAVA密码:

public Cryptor(boolean reader) throws CryptingException {

    keySpec = new SecretKeySpec(secretKey.getBytes(CHARSET), "AES");
    ivSpec = new IvParameterSpec(iv.getBytes(CHARSET));
    try {
        cipher = Cipher.getInstance("AES/CFB8/NoPadding");
        if (reader) cipher.init(Cipher.DECRYPT_MODE, keySpec, ivSpec);
        else cipher.init(Cipher.ENCRYPT_MODE, keySpec, ivSpec);
    } catch (NoSuchAlgorithmException e) {
        throw new SecurityException(e);
    } catch (NoSuchPaddingException e) {
        throw new SecurityException(e);
    }catch (InvalidKeyException e) {
        throw new SecurityException(e);
    } catch (InvalidAlgorithmParameterException e) {
        throw new SecurityException(e);
    }
}

public byte[] decrypt(byte[] input) throws CryptingException {
        return cipher.update(input);
}

public byte[] encrypt(String input) throws CryptingException {
    return cipher.update(input.getBytes());
}

Java测试代码:

private static void Test() {
    // Init
    String data = createDataSize(9392963);
    Cryptor writer = new Cryptor(false);

    // Timer
    Instant starts = Instant.now();
    byte[] encrypted = writer.encrypt(data);
    Instant ends = Instant.now();
    System.out.println("Java Encryption took: " + Duration.between(starts, ends));
}
private static String createDataSize(int msgSize) {
      StringBuilder sb = new StringBuilder(msgSize);
      for (int i=0; i<msgSize; i++) {
        sb.append('a');
      }
      return sb.toString();
}

结果:“ Java加密使用:PT0.469S”

可能的解决方案:

经过大量研究之后,看来AesCryptoServiceProvider()的性能与Java的等效性能大致相同,并且结果大部分相同。但是,与此相关的问题是它需要填充,而Java的等效性不需要填充。例如,这意味着如果我要加密“ abcdab”,它将仅加密“ abcd”并返回该结果,并将其余结果(“ ab”)保留在内部。如果我使用填充,我可以让它返回完整的加密“ abcdab”,但是它会附加其他数据,并且对称算法将不同步,因为在Java中,我可以加密“ abcdab”而无需任何填充。

问题

所以最后我的问题是,我将如何使C#加密/解密过程与Java一样快?我在AesCryptoServiceProvider上做错了什么,也许它可能不需要填充?

0 个答案:

没有答案