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在花时间阅读本文之前，请参阅下面的自我回答。问题是输入无效。

当我尝试解密一些字符串时，它会抛出这个异常：

    "   at System.Security.Cryptography.RijndaelManagedTransform.DecryptData(Byte[] inputBuffer, Int32 inputOffset, Int32 inputCount, Byte[]& outputBuffer, Int32 outputOffset, PaddingMode paddingMode, Boolean fLast)
       at System.Security.Cryptography.RijndaelManagedTransform.TransformFinalBlock(Byte[] inputBuffer, Int32 inputOffset, Int32 inputCount)
       at System.Security.Cryptography.CryptoStream.FlushFinalBlock()
       at System.Security.Cryptography.CryptoStream.Dispose(Boolean disposing)
       at System.IO.Stream.Close()
       at System.IO.Stream.Dispose()
       at EBookReader.cryptography.DecryptString(String message, String KeyString, String IVString) in C:\\Users\\XWare\\Documents\\Visual Studio 2008\\Projects\\EBookReader\\EBookReader\\cryptography.cs:line 94"

在调试下它会在这一行抛出异常：

    byte[] messageBytes = Convert.FromBase64String(message);

我认为当要解密的字符串太大时才会出现这个问题，因为当我尝试加密和解密像“ Hi there I am X-Ware ”这样的短字符串时，它工作正常

    public static string DecryptString(string message, string KeyString, string IVString)
    {
        byte[] Key = ASCIIEncoding.UTF8.GetBytes(KeyString);
        byte[] IV = ASCIIEncoding.UTF8.GetBytes(IVString);

        string decrypted = null;
        RijndaelManaged rj = new RijndaelManaged();
        rj.BlockSize = 256;
        rj.Key = Key;
        rj.IV = IV;
        rj.Mode = CipherMode.CBC;
        rj.Padding = PaddingMode.PKCS7;
        try
        {
            MemoryStream ms = new MemoryStream();
            Encoding enc = new ASCIIEncoding();
            using (CryptoStream cs = new CryptoStream(ms, rj.CreateDecryptor(Key, IV), CryptoStreamMode.Write))
            {
                byte[] messageBytes = Convert.FromBase64String(message);
                cs.Write(messageBytes, 0, messageBytes.Length);
                cs.FlushFinalBlock();  
            }// This is line 94
            byte[] encoded = ms.ToArray();
            decrypted = enc.GetString(encoded);

            ms.Close();
        }
        catch (Exception e)
        {
            Console.WriteLine("An error occurred: {0}", e.Message);
        }
        finally
        {
            rj.Clear();
        }

        return decrypted;
    }

有什么建议么 ？！

PS我写了一条评论给你看第94行//这是第94行

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2 回答 2

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该FlushFinalBlock方法仅用于刷新最后一个完整或部分字节块。因此，如果您编写的块大小超过单个块大小，则它不是正确的方法调用。在尝试从内存流中读取之前，请尝试简单地关闭加密流。

要在您的代码上下文中执行此操作，只需删除该行cs.FlushFinalBlock()...

于 2012-01-12T13:52:06.197 回答
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问题是我作为Base64字符串传递的字符串无效问题只是在输入文件中，这使得解密不可能

谢谢大家

于 2012-01-14T12:56:51.483 回答