Deserializing an Object

[Simon Canning]

I am having trouble deserializing an encrypted object. This is the error:

Failed to deserialize. Reason: End of Stream encountered before parsing was completed

Here is my code:

Imports System.IO
Imports System.Security.Cryptography
Imports System.Runtime.Serialization
Imports System.Runtime.Serialization.Formatters.Binary
Imports System.Text

Module TestModEncryption

Public Sub SaveEncryptedObjectToFile(FileName As String, Item As Object)
Dim fs As FileStream
Dim encryptor As CryptoStream

Dim formatter As New BinaryFormatter

Dim password As String = "MyPassword"
Dim salt As String = "InitialVector123"

Dim AES As AesManaged = New AesManaged
AES.Padding = PaddingMode.None
AES.Mode = CipherMode.CBC

Dim HashAlgorithm As String = "SHA1" Can be SHA1 or MD5
Dim PasswordIterations As Integer = 2
Dim InitialVector As String = "InitialVector123" This should be a string of 16 ASCII characters.
Dim KeySize As Integer = 256 Can be 128, 192, or 256.

Dim InitialVectorBytes As Byte() = Encoding.ASCII.GetBytes(InitialVector)
Dim SaltValueBytes As Byte() = Encoding.ASCII.GetBytes(salt)
Dim DerivedPassword As New Rfc2898DeriveBytes(password, SaltValueBytes, PasswordIterations)
Dim KeyBytes As Byte() = DerivedPassword.GetBytes(CInt(KeySize / 8))

Dim encryptTransf As ICryptoTransform = AES.CreateEncryptor(KeyBytes, InitialVectorBytes)

fs = New FileStream(FileName, FileMode.Create)
encryptor = New CryptoStream(fs, encryptTransf, CryptoStreamMode.Write)

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

Public Function OpenEncryptedObjectFromFile(FileName As String) As Object
Dim fs As New FileStream(FileName, FileMode.Open)
Dim decryptor As CryptoStream

Dim ItemToReturn As New Object

Dim password As String = "MyPassword"
Dim salt As String = "InitialVector123"

Dim AES As AesManaged = New AesManaged
AES.Padding = PaddingMode.None
AES.Mode = CipherMode.CBC

Dim HashAlgorithm As String = "SHA1" Can be SHA1 or MD5
Dim PasswordIterations As Integer = 2
Dim InitialVector As String = "InitialVector123" This should be a string of 16 ASCII characters.
Dim KeySize As Integer = 256 Can be 128, 192, or 256.

Dim InitialVectorBytes As Byte() = Encoding.ASCII.GetBytes(InitialVector)
Dim SaltValueBytes As Byte() = Encoding.ASCII.GetBytes(salt)
Dim DerivedPassword As New Rfc2898DeriveBytes(password, SaltValueBytes, PasswordIterations)
Dim KeyBytes As Byte() = DerivedPassword.GetBytes(CInt(KeySize / 8))

Dim decryptTrans As ICryptoTransform = AES.CreateDecryptor(KeyBytes, InitialVectorBytes)

Try
Dim formatter As New BinaryFormatter

decryptor = New CryptoStream(fs, decryptTrans, CryptoStreamMode.Read)
ItemToReturn = DirectCast(formatter.Deserialize(decryptor), Object)
Return ItemToReturn
Catch e As SerializationException
MsgBox("Failed to deserialize. Reason: " & e.Message)
Return Nothing
Throw
Finally
fs.Close()
End Try
End Function

End Module

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