Database

Private Function decryption()

        'This is function is the same as encryption with just a few changes'
        'loading the xml document'


        Dim key As Byte()
        Dim IV As Byte()


        'The hardcoded password goes here'
        'This is a section just in case you want to a password to your encrypted files'
        key = keyencryption(LoginForm.Password_TextBox.Text)
        IV = IVCreation(LoginForm.Password_TextBox.Text)
        'if there is an error in the application. A error message will be displayed'
        Try

            'checking to make sure the text box isn't null'
            If (Decrypt_TextBox.Text = "") Then
                MessageBox.Show("Need to put in the file location or select file in grid for decryption")
            Else

                'declaring string for file'
                Dim filename As String
                'Getting the file name that is selected'
               
                filename = getFilename()
                'Starting to abstract the data from the database'
                database.ConnectionString = "Data Source = FileVault.db3;"
                database.Open()
                Dim command As SQLite.SQLiteCommand
                Dim sqlstatement As String
                command = database.CreateCommand
                'The following will get the bytes of the file'
                Dim filesize As Integer
                sqlstatement = "SELECT FileSize From Vault WHERE FileName=@file;"
                command.CommandText = sqlstatement
                command.Parameters.AddWithValue("@file", filename)
                Dim reader As SQLite.SQLiteDataReader
                reader = command.ExecuteReader
                filesize = reader.GetValue(0)
                reader.Close()
                MessageBox.Show(filesize)
                Dim data(filesize) As Byte
                'The following should get the data'
                sqlstatement = "SELECT FileData FROM Vault WHERE FileName=@file;"
                command.CommandText = sqlstatement
                command.Parameters.AddWithValue("@file", filename)

                Dim buf() As Byte


                'This gets the file from the database'
                reader = command.ExecuteReader


                'The following should get the file back to its original form'
                buf = reader.GetValue(0)




                'This is go into the Safe and retrieve file'
                Dim datawrite As New System.IO.FileStream("Safe", IO.FileMode.Open, IO.FileAccess.ReadWrite)
                datawrite.SetLength(0)
                datawrite.Write(buf, 0, buf.Length)
                datawrite.Close()
                reader.Close()
                Dim fileinput As New System.IO.FileStream("Safe", IO.FileMode.Open, IO.FileAccess.ReadWrite)

                'specific file output location wiht proper extension'
                Dim fileoutput As New System.IO.FileStream(Decrypt_TextBox.Text & "\" & filename, IO.FileMode.OpenOrCreate, IO.FileAccess.Write)
                'The next line makes sure that the file is empty'

                'Declaring variables for encryption'

                Dim buffer(4096) As Byte 'Holds the bytes for processing

                Dim BytesProcessed As Double 'running count for bytes that are processed'

                Dim filelength As Double = fileinput.Length() 'Length of file coming in where intEnd will be greater than intStart'

                Dim bytesinblock As Integer 'current bytes in block'

                Dim crypto As CryptoStream

                'Declaring crypto service provider'
                Dim scRijndael As New System.Security.Cryptography.RijndaelManaged

                'setting up progress bars
                Encrypt_ProgressBar.Value = 0
                Encrypt_ProgressBar.Maximum = 100

                crypto = New CryptoStream(fileoutput, scRijndael.CreateDecryptor(key, IV), CryptoStreamMode.Write)

                While (fileinput.Read(buffer, 0, 4096) > 0)
                    'reading the file'
                    bytesinblock = buffer.Length
                    'writing the file to cryptoStream'
                    crypto.Write(buffer, 0, bytesinblock)
                    'updating bytes processed'
                    BytesProcessed = BytesProcessed + CLng(bytesinblock)
                    'equation for updating bytes in block'
                    Decrypt_ProgressBar.Value = CInt((BytesProcessed / filelength) * 100)
                End While

                crypto.Close()
                fileinput.SetLength(0)
                fileoutput.Close()
                fileinput.Close()

                MessageBox.Show("File is done decrypting")
                Decrypt_ProgressBar.Step = 0
                Decrypt_ProgressBar.Value = 0
                Decrypt_TextBox.Text = ""
            End If

        Catch ex As Exception
            MsgBox(ex.Message.ToString)
            

        End Try

        Return 1