DES序列化異常

Question

我和我在使用DES加密技術反序列化對象時遇到了一些麻煩。

我收到一個異常，說「壞數據」。在DeserializeDESObjectFromFile功能。

我可以請一些幫助，讓這個工作？

這裏是我的代碼：

Public Sub SerializeDESObjectToFile(FileName As String, Item As Object) 
    Dim fs As FileStream 
    Dim formatter As New BinaryFormatter 

    Dim DESKey() As Byte = {200, 5, 78, 232, 9, 6, 0, 4} 
    Dim DESInitializationVector() As Byte = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9} 
    Dim MyStreamEncrypter As CryptoStream = Nothing 

    fs = New FileStream(FileName, FileMode.Create) 
    Dim DESAlgorithm As DES 
    DESAlgorithm = New DESCryptoServiceProvider 
    MyStreamEncrypter = New CryptoStream(fs, DESAlgorithm.CreateEncryptor(DESKey, DESInitializationVector), CryptoStreamMode.Write) 

    Try 
     formatter.Serialize(MyStreamEncrypter, Item) 
    Catch e As Exception 
     Console.WriteLine("Failed to serialize. Reason: " & e.Message) 
    Finally 
     fs.Close() 
    End Try 
End Sub 

Public Function DeserializeDESObjectFromFile(FileName As String) As Object 
    Dim fs As New FileStream(FileName, FileMode.Open) 
    Dim ItemToReturn As New Object 

    Dim DESKey() As Byte = {200, 5, 78, 232, 9, 6, 0, 4} 
    Dim DESInitializationVector() As Byte = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9} 
    Dim MyStreamDecrypter As CryptoStream = Nothing 

    Dim DESAlgorithm As DES 
    DESAlgorithm = New DESCryptoServiceProvider 

    MyStreamDecrypter = New CryptoStream(fs, DESAlgorithm.CreateDecryptor(DESKey, DESInitializationVector), CryptoStreamMode.Read) 

    Try 
     Dim formatter As New BinaryFormatter 
     ItemToReturn = DirectCast(formatter.Deserialize(MyStreamDecrypter), Object) 
     Return ItemToReturn 
    Catch e As Exception 
     MsgBox(e.Message) 
     Return Nothing 
    Finally 
     fs.Close() 
    End Try 
End Function 

Answer 1

重要的是要確保在流中的最後一個塊刷新是很重要的。分組密碼模式（如ECB模式和CBC模式）需要填充，因爲分組密碼只能加密完整的明文塊。由於流不知道您的序列化數據對象是它必須加密的最後一個數據，因此它無法填充和加密最後一個塊本身。

在將最後一個純文本數據寫入CryptoStream後，應調用FlushFinalBlock。或者，您可以在CryptoStream上調用close()而不是底層的流，或者確保之前的在基礎流上調用close()。