問題描述

我已在網上查找此異常與我的程序相關的含義，但似乎找不到解決方案或我的特定程序發生此異常的原因.我一直在使用我的 msdn 提供的示例來使用 Rijndael 算法加密和解密 XmlDocument.加密工作正常，但當我嘗試解密時，出現以下異常:

I have looked online for what this?exception means in relation to my?program?but can't seem to find a solution or the reason why it's happening to my specific program. I have been using the example provided my msdn for encrypting and decrypting an XmlDocument using the Rijndael algorithm. The encryption works fine but when I try to decrypt, I get the following exception:

填充無效，無法移除

誰能告訴我我能做些什么來解決這個問題?下面的代碼是我獲取密鑰和其他數據的地方.如果cryptoMode為false，就會調用decrypt方法，也就是異常發生的地方:

Can anyone tell me what I can do to solve this issue? My code below is where I get the key and other data. If the cryptoMode is false, it will call the decrypt method, which is where the exception occurs:

public void Cryptography(XmlDocument doc, bool cryptographyMode)
{
    RijndaelManaged key = null;
    try
    {
    // Create a new Rijndael key.
    key = new RijndaelManaged();
    const string passwordBytes = "Password1234"; //password here 

    byte[] saltBytes = Encoding.UTF8.GetBytes("SaltBytes");
    Rfc2898DeriveBytes p = new Rfc2898DeriveBytes(passwordBytes, saltBytes);
    // sizes are devided by 8 because [ 1 byte = 8 bits ] 
    key.IV = p.GetBytes(key.BlockSize/8);
    key.Key = p.GetBytes(key.KeySize/8);

    if (cryptographyMode)
    {
        Ecrypt(doc, "Content", key);
    }
    else
    {
        Decrypt(doc, key);
    }

    }
    catch (Exception ex)
    {
    MessageBox.Show(ex.Message);
    }
    finally
    {
    // Clear the key.
    if (key != null)
    {
        key.Clear();
    }
    }

}

private void Decrypt(XmlDocument doc, SymmetricAlgorithm alg)
{
    // Check the arguments.  
    if (doc == null)
    throw new ArgumentNullException("Doc");
    if (alg == null)
    throw new ArgumentNullException("alg");

    // Find the EncryptedData element in the XmlDocument.
    XmlElement encryptedElement = doc.GetElementsByTagName("EncryptedData")[0] as XmlElement;

    // If the EncryptedData element was not found, throw an exception.
    if (encryptedElement == null)
    {
    throw new XmlException("The EncryptedData element was not found.");
    }


    // Create an EncryptedData object and populate it.
    EncryptedData edElement = new EncryptedData();
    edElement.LoadXml(encryptedElement);

    // Create a new EncryptedXml object.
    EncryptedXml exml = new EncryptedXml();


    // Decrypt the element using the symmetric key.
    byte[] rgbOutput = exml.DecryptData(edElement, alg); <----  I GET THE EXCEPTION HERE
    // Replace the encryptedData element with the plaintext XML element.
    exml.ReplaceData(encryptedElement, rgbOutput);

}

推薦答案

Rijndael/AES 是一個塊密碼.它以 128 位(16 個字符)塊加密數據.加密填充用于確保消息的最后一個塊始終是大小正確.

Rijndael/AES is a block cypher. It encrypts data in 128 bit (16 character) blocks. Cryptographic padding is used to make sure that the last block of the message is always the correct size.

您的解密方法期望它的默認填充是什么，并且沒有找到它.正如@NetSquirrel 所說，您需要為加密和解密顯式設置填充.除非您有理由不這樣做，否則請使用 PKCS#7 填充.

Your decryption method is expecting whatever its default padding is, and is not finding it. As @NetSquirrel says, you need to explicitly set the padding for both encryption and decryption. Unless you have a reason to do otherwise, use PKCS#7 padding.

這篇關于填充無效，無法刪除?的文章就介紹到這了，希望我們推薦的答案對大家有所幫助，也希望大家多多支持html5模板網！