Reading/Writing bytes help.

[tassa]

Hello...

I'm trying to read 5 bytes from a file and then do something according to what has been read. This is my code (I'll explain in a bit what's wrong):

cStream = New CryptoStream(input, _
                           RijndaelAlg.CreateDecryptor(_key, IV), _
                           CryptoStreamMode.Read)
 
                    Dim HeaderBuffer(4) As Byte
                    cStream.Read(HeaderBuffer, 0, 5)
 
                    If encoding.GetString(HeaderBuffer) <> HeaderString Then
                        RaiseEvent ReturnType(ActionReturnType.InvalidPassword)
                        cStream.Clear()
                        Exit Try
                    End If
 
                    Do While BytesProcessed < SourceLength
                        CurrentBytes = cStream.Read(Buffer, 0, 4096)
                        output.Write(Buffer, 0, CurrentBytes)
                        BytesProcessed += CLng(CurrentBytes)
                        PercentDone = CInt((BytesProcessed / SourceLength) * 100)
                        RaiseEvent Progress(PercentDone)
                    Loop

It reads the 5 bytes I added to the encrypted file, but I want the CryptoStream to start from the sixth value and then copy the original bytes into the decrypted file, but it gives me an error:

Padding is invalid and cannot be removed.

That's why I'm trying to make it read from the sixth value and then continue copying normally, but I'm stuck.

Any help will be greatly appreciated!

Thanks .