CODEWITHSUNDEEP
vb.netencryptionfilestream
user141531315
user141531315

Reputation: 11

Warning Variable 'csCryptoStream' is used before it has been assigned a value. A null reference exception could result at runtime

Im new to VB.Net. I am trying to debug my project, but I get a warning: Variable 'csCryptoStream' is used before it has been assigned a value. A null reference exception could result at runtime

How can I fix it?

Private Sub EncryptOrDecryptFile(strInputFile As String, strOutputFile As String, bytKey As Byte(), bytIV As Byte(), Direction As crypt.CryptoAction)
    ' The following expression was wrapped in a checked-statement
    Try
        Me.fsInput = New FileStream(strInputFile, FileMode.Open, FileAccess.Read)
        Me.fsOutput = New FileStream(strOutputFile, FileMode.OpenOrCreate, FileAccess.Write)
        Me.fsOutput.SetLength(0L)
        Dim bytBuffer As Byte() = New Byte(4096) {}
        Dim lngBytesProcessed As Long = 0L
        Dim lngFileLength As Long = Me.fsInput.Length
        Dim cspRijndael As RijndaelManaged = New RijndaelManaged()
        Me.pbStatus.Value = 0
        Me.pbStatus.Maximum = 100
        Dim csCryptoStream As CryptoStream
        Select Case Direction
            Case crypt.CryptoAction.ActionEncrypt
                csCryptoStream = New CryptoStream(Me.fsOutput, cspRijndael.CreateEncryptor(bytKey, bytIV), CryptoStreamMode.Write)
            Case crypt.CryptoAction.ActionDecrypt
                csCryptoStream = New CryptoStream(Me.fsOutput, cspRijndael.CreateDecryptor(bytKey, bytIV), CryptoStreamMode.Write)
        End Select
        While lngBytesProcessed < lngFileLength
            Dim intBytesInCurrentBlock As Integer = Me.fsInput.Read(bytBuffer, 0, 4096)

Warning --->     csCryptoStream.Write(bytBuffer, 0, intBytesInCurrentBlock)
            ' The following expression was wrapped in a unchecked-expression
            lngBytesProcessed += CLng(intBytesInCurrentBlock)
            ' The following expression was wrapped in a unchecked-expression
            Me.pbStatus.Value = CInt(Math.Round(CDec(lngBytesProcessed) / CDec(lngFileLength) * 100.0))
        End While

Upvotes: 0

Views: 523

Answers (1)

alwaysVBNET
alwaysVBNET

Reputation: 3310

  1. Declare the CryptoStream as below:

     Dim csCryptoStream As CryptoStream = Nothing

  2. Add a 'Case Else' clause in your Case/Select

  3. Before using this variable check if

    If Not IsNothing(csCryptoStream)
  '    ....
End If

Upvotes: 0

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