Sciguyryan's Blog

It has been a while since I last posted a code sample. So here is one for you guys to take a look at. Below is the file/directory shredder class.

class FileUtilities
{
    private static Random Randomizer = new Random();

    public static bool Shred(string directoryPath, bool shouldDelete = true)
    {
        bool success = true;
        try
        {
            string[] files = Directory.GetFiles(directoryPath, "*", SearchOption.AllDirectories);
            foreach (string file in files)
                success &= FileUtilities.ShredFile(file, shouldDelete);

            string[] directories = Directory.GetDirectories(
                directoryPath,
                "*",
                SearchOption.AllDirectories
            ).OrderByDescending(
                str =>
                str.Split('\\').Length - 1
            ).ToArray();
            foreach (string directory in directories)
                success &= FileUtilities.ShredDirectory(directory, shouldDelete);

            success &= FileUtilities.ShredDirectory(directoryPath, shouldDelete);
        }
        catch
        {
            success = false;
        }
        return success;
    }

    public static bool ShredDirectory(string directoryPath, bool shouldDelete = true)
    {
        bool success = true;
        try
        {
            DirectoryInfo directoryInfo = new DirectoryInfo(directoryPath);

            string[] directoryBits = directoryPath.Split('\\');
            directoryBits[directoryBits.Length - 1] = FileUtilities.RandomName(directoryInfo.Name.Length);

            string newDirectoryPath = String.Join("\\", directoryBits);
            directoryInfo.MoveTo(newDirectoryPath);

            if (shouldDelete)
                directoryInfo.Delete();
        }
        catch
        {
            success = false;
        }
        return success;
    }

    public static bool ShredFile(string filePath, bool shouldDelete = true)
    {
        bool success = true;
        try
        {
            FileStream fs = new FileStream(filePath, FileMode.Open, FileAccess.Write);
            for (long i = 0; i < fs.Length; i++)
                fs.WriteByte((byte)Randomizer.Next(0, 255));

            fs.Close();

            FileInfo fileInfo = new FileInfo(filePath);
            fileInfo.MoveTo(fileInfo.DirectoryName + @"\" + FileUtilities.RandomName(fileInfo.Name.Length));

            if (shouldDelete)
                fileInfo.Delete();
        }
        catch
        {
            success = false;
        }
        return success;
    }

    private static string RandomName(int length)
    {
        string fileNameChars = "abcdefghijklmnopqrstuvwxyz1234567890ABCDEFGHIJKLMNOPQRSTUVWXYZ~!@¤#$£§%^&()+`={}][;,";
        string newFileName = String.Empty;
        for (int i = 0; i < length; i++)
            newFileName += fileNameChars[Randomizer.Next(0, fileNameChars.Length)];

        return newFileName;
    }
}

The usage calls for these functions as as follows:

bool success = FileUtilities.Shred(@"D:\Temp"); // This method will recursively shred a file / folder.
bool success = FileUtilities.ShredDirectory(@"D:\Temp"); // This method will shred the contents of a folder and the root folder.
bool success = FileUtilities.ShredFile(@"D:\Temp\test.txt"); // This method will shred a specified file.[

I will not go through the code line-by-line to explain it as I feel most of the code is pretty self-explanatory. However if there are any questions feel free to post a comment.