Rijndael填充或长度无效 [英] Rijndael padding or length is invalid
问题描述
我正在尝试使用Rijndael或Aes和下面的代码对字符串进行加密/解密。
I am trying to encrypt/decrypt a string using eith Rijndael or Aes and the code below.
public class Crypto
{
private const string defaultVector = "asdfg123456789";
private const CipherMode cipherMode = CipherMode.CBC;
//Have tried PaddingMode.ISO10126, PaddingMode.None, and PaddingMode.PKCS7
private const PaddingMode paddingMode = PaddingMode.ISO10126;
private const int iterations = 2;
private static Rijndael GetCrypto(string passphrase)
{
var crypt = Rijndael.Create();
crypt.Mode = cipherMode;
crypt.Padding = paddingMode;
crypt.BlockSize = 256;
crypt.KeySize = 256;
crypt.Key =
new Rfc2898DeriveBytes(passphrase, Encoding.Unicode.GetBytes(defaultVector), iterations).GetBytes(32);
crypt.IV = new Rfc2898DeriveBytes(passphrase, Encoding.Unicode.GetBytes(defaultVector), iterations).GetBytes(32);
return crypt;
}
public static string Encrypt(string plainText, string passphrase)
{
byte[] clearData = Encoding.Unicode.GetBytes(plainText);
byte[] encryptedData;
var crypt = GetCrypto(passphrase);
using (var ms = new MemoryStream())
{
using (var cs = new CryptoStream(ms, crypt.CreateEncryptor(), CryptoStreamMode.Write))
{
cs.Write(clearData, 0, clearData.Length);
//cs.FlushFinalBlock(); //Have tried this active and commented with no change.
}
encryptedData = ms.ToArray();
}
//Changed per Xint0's answer.
return Convert.ToBase64String(encryptedData);
}
public static string Decrypt(string cipherText, string passphrase)
{
//Changed per Xint0's answer.
byte[] encryptedData = Convert.FromBase64String(cipherText);
byte[] clearData;
var crypt = GetCrypto(passphrase);
using (var ms = new MemoryStream())
{
using (var cs = new CryptoStream(ms, crypt.CreateDecryptor(), CryptoStreamMode.Write))
{
cs.Write(encryptedData, 0, encryptedData.Length);
//I have tried adding a cs.FlushFinalBlock(); here as well.
}
clearData = ms.ToArray();
}
return Encoding.Unicode.GetString(clearData);
}
}
//编辑：我已经对Unicode调用进行了更改根据下面的Xint0的答案转换为Convert.ToBase64String。
//Edits: I have changed over the Unicode calls to Convert.ToBase64String per Xint0's answer below.
在cs.Write in Decrypt方法上，我收到以下错误：填充无效，无法删除。
On the cs.Write in Decrypt method, I am getting the error that "Padding is invalid and cannot be removed."
我尝试将填充设置为PaddingMode.None，但得到要加密的数据长度无效。
I have tried setting the padding to PaddingMode.None but I get "Length of the data to encrypt is invalid." on the cs.Write in the Encrypt method.
我已经看过这些了，但是他们说的什么似乎都不起作用。
I've looked at these and nothing they've said seems to work.
堆栈跟踪显示System.Security.CryptographicException来自RijndaelManagedTransform.DecryptData（Byte [] inputBuffer，Int32 inputOffset，Int32 inputCount，Byte []& outputBuffer，Int32 outputOffset，PaddingMode paddingMode，布尔值fLast）。
Stack trace shows System.Security.CryptographicException is coming from RijndaelManagedTransform.DecryptData(Byte[] inputBuffer, Int32 inputOffset, Int32 inputCount, Byte[]& outputBuffer, Int32 outputOffset, PaddingMode paddingMode, Boolean fLast).
推荐答案
我看到两个问题：
-
在调用
ms.ToArray（）之前，您并没有刷新和关闭流。更改为：
You are not flushing and closing the streams before calling
ms.ToArray(). Change it to:
...
using (var cs = new CryptoStream(ms, crypt.CreateEncryptor(), CryptoStreamMode.Write))
{
cs.Write(clearData, 0, clearData.Length);
cs.FlushFinalBlock();
cs.Close();
}
ms.Close();
encryptedData = ms.ToArray();
...
在加密得到的字节数组 encryptedData 是否一个Unicode字符串，但是您正在使用Unicode编码器从字节数组中获取字符串。而不是使用 Encrypt 和 System.Convert中的。 System.Convert.ToBase64String（）。 解密中的FromBase64String（）
In Encrypt the resulting byte array encryptedData is NOT a Unicode string, yet you are using a Unicode encoder to get a string from the byte array. Instead of that use System.Convert.ToBase64String() in Encrypt and System.Convert.FromBase64String() in Decrypt.
在加密中执行
return System.Convert.ToBase64String(encryptedData);
在解密中执行：
byte[] encryptedData = System.Convert.FromBase64String(cipherText);
编辑
最大的问题是 Encrypt 的返回值。加密Unicode字符串的字节表示形式的结果是 NOT 的Unicode字符串的字节表示形式。您不应将 encryptedData 的值与 Encoding.Unicode.GetString（）一起使用，以获取加密后的字符串表示形式数据。使用 System.Convert.ToBase64String（）获取加密数据的字符串表示形式。请参阅编码类 MSDN文档中的备注部分。
The biggest problem is the return value of Encrypt. The result of encrypting the byte representation of a Unicode string is NOT a byte representation of a Unicode string. You should not use the value of encryptedData with Encoding.Unicode.GetString() to get a string representation of the encrypted data. Use System.Convert.ToBase64String() to get a string representation of the encrypted data. Please see the Remarks section in the Encoding Class MSDN Documentation.
编辑2
请注意，如果您要与AES互操作，Rijndael并非完全是AES块大小应始终为128位，与密钥大小无关。有关详细信息，您可以阅读此处。
Note that Rijndael is not exactly AES, if you are interoperating with AES the block size should always be 128-bits, independent of the key size. For details you can read about it here.
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