Convert decrypt file in php from vb.net

Question

How to Decrypt this file in php . using MySqlBackup.net library in vb.net project. help me to solve or provide valid solution.

Dim filePath As String = Path.GetDirectoryName(Application.ExecutablePath) & "\"
    Dim constring As String = connectionstring
    Dim file As String = Path.GetDirectoryName(Application.ExecutablePath) + "\backup.mdf"
    Using conn As New MySqlConnection(constring)
        Using cmd As New MySqlCommand()
            Using mb As New MySqlBackup(cmd)
                cmd.Connection = conn
                conn.Open()
                mb.ExportToFile(file)
                mb.EncryptDumpFile(file, filePath & Now.ToString("dd-MM-yyyy", CultureInfo.InvariantCulture) & ".mdf", Settings1.Default.password)
                My.Computer.Network.UploadFile(filePath & Now.ToString("dd-MM-yyyy", CultureInfo.InvariantCulture) & ".mdf", "http://localhost/reg/reg.php")
                ' My.Computer.FileSystem.DeleteFile(file)
                conn.Close()
            End Using
        End Using
    End Using