为C#bouncycastle编写PHP MCrypt twofish [英] writing php MCrypt twofish for c# bouncycastle

问题描述

我正在学习如何使用BouncyCastle c#密码库进行加密.我不想发送邮件，所以我没有考虑安全性等. 我已经在Visual Studio中编写了我的C#代码.

I'm learning how to use the BouncyCastle c# cipher library for doing encryption. I'm not looking to send messages so I'm not thinking about security etc. I have written my c# code in Visual Studio.

这是问题所在.我已经在CFB模式下使用Twofish对文本" Hello World！"进行了加密.密钥是1234567812345678.我使用了phpfiddle http://phpfiddle.org/在线工具.

Here is the problem. I have encrypted the text "Hello World!", using Twofish in CFB mode. The key is 1234567812345678. I've used phpfiddle http://phpfiddle.org/ online tool.

$algo = 'twofish';
$mode = 'cfb';

$cipher = mcrypt_module_open($algo,'',$mode,'');

$key = hex2bin('31323334353637383132333435363738'); //1234567812345678
$iv = hex2bin('00000000000000000000000000000000');

mcrypt_generic_init($cipher, $key, $iv);

$plaintext = utf8_encode('Hello World!');
$encrypted = mcrypt_encrypt($algo, $key, $plaintext, $mode, $iv);
printf("<br>Encrypted text: %s<br><br>",base64_encode($encrypted));

$decrypted = mcrypt_decrypt($algo, $key, $encrypted, $mode, $iv);
printf("<br>Decrypted text: %s (%s)<br><br>",$decrypted,bin2hex($decrypted));

mcrypt_generic_deinit($cipher);
mcrypt_module_close($cipher);

结果如下

cfdJ + M6MAzG4WJMb(Base64)

cfdJ+M6MAzG4WJMb (Base64)

然后我创建了一个c#版本来解密相同的文本

I have then created a c# version to decrypt the same text

// ASCII encoding and Zero padding
encoding = Encoding.ASCII
padding = IBlockCipherPadding.zeroBytePadding

// Set up the engine and cipher types
baseCipher = new TwofishEngine();
blockSize = baseCipher.GetBlockSize();    

modeCipher = new CfbBlockCipher(baseCipher, blockSize);
cipher = padding == null ? new PaddedBufferedBlockCipher(modeCipher) : new PaddedBufferedBlockCipher(modeCipher, padding);

// convert the strings to byte array and create a dummy 000000.. iv 

byte[] iv = new byte[blockSize];    // i.e. 16 bytes of zero
keyBytes = _encoding.GetBytes(key);   //1234567812345678
inputBytes = Convert.FromBase64String(inp);

// initiate the cipher with iv parameters
cipher.Init(true, new ParametersWithIV(new KeyParameter(keyBytes), iv));

// do the decryption
console.write(_encoding.GetString(cipher.DoFinal(inputBytes)) + "\n";)

但这给了我很多垃圾.我得到HIl1oVW rEdIp

But this gives me garbage out. I get HIl1oVW�rEdIp�

关闭(H.l.o.W.r.d.)，但每隔一个字母都是错误的！

Close (H.l.o.W.r.d.) but every other letter is wrong!

ECB模式可以正常工作，因此必须与初始化向量有关.

ECB mode works fine so it must be something to do with the initialization vector.

我还没有学过PHP和c#之间的一些区别吗?

Are there some differences between PHP and c# that I havn't learnt yet?

在这种情况下，我的C#代码在哪里不正确?

Where is my c# code incorrect in that case?

推荐答案

确定.所以我终于解决了.我对密码块模式的理解是一个基本错误. CFB和OFB是流密码，不是填充缓冲块密码.

OK. So I solved it finally. A basic error in my understanding of cipher block modes. CFB and OFB are Stream Ciphers not Padded Buffered block ciphers.

因此，密码设置应该已经

Therefore the cipher setup should have been

modeCipher = new CfbBlockCipher(baseCipher,8);      // Allways 8 bits for a stream cipher !!
cipher = new StreamBlockCipher(modeCipher);

(cipher.doFinal也已更改，但此处未显示)

(The cipher.doFinal was changed too but not shown here)

现在可以正常工作了.

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