Question

我在使用DES加密反序列化对象时遇到了一些麻烦。

我收到一条说“不良数据”的异常。在DeserializeDESObjectFromFile函数中。

我可以帮忙解决这个问题吗？

这是我的代码：

    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

确保刷新流中的最后一个块非常重要。需要填充诸如ECB模式和CBC模式的分组密码模式，因为分组密码只能加密完整的明文块。由于流不知道您的序列化数据对象是它必须加密的最后一个数据，因此它无法填充和加密最后一个块本身。

在将最后一个纯文本数据写入CryptoStream后，应调用FlushFinalBlock。或者，您可以在上部close()而不是基础流上调用CryptoStream，或者确保在上调用基础流上的close()之前正确处理。

DES序列化例外

1 个答案: