CompleteEraser/FileBreaker.cs

   1 using System;\r
   2 using System.Text;\r
   3 using System.Collections.Generic;\r
   4 using System.IO;\r
   5 using System.Security.AccessControl;\r
   6 using System.Security.Principal;\r
   7 using System.Linq;\r
   8 using Trinet.Core.IO.Ntfs;\r
   9 using CompleteEraser.Properties;\r
  10 \r
  11 namespace CompleteEraser\r
  12 {\r
  13     class FileBreaker\r
  14     {\r
  15         const long ShirnkLength = 1;\r
  16 \r
  17         public static void BreakFileOrFolder(string path)\r
  18         {\r
  19             if (Directory.Exists(path))\r
  20                 BreakFolder(path);\r
  21             else if (File.Exists(path))\r
  22                 BreakFile(path);\r
  23         }\r
  24 \r
  25         public static void BreakFile(string file)\r
  26         {\r
  27             FileAttributes attr = File.GetAttributes(file);\r
  28             if ((attr & FileAttributes.ReadOnly) == FileAttributes.ReadOnly)\r
  29                 File.SetAttributes(file, attr & ~FileAttributes.ReadOnly);\r
  30 \r
  31             string ext = Path.GetExtension(file);\r
  32 \r
  33             FileStream fs;\r
  34             FileInfo info = new FileInfo(file);\r
  35             foreach (AlternateDataStreamInfo alt in info.ListAlternateDataStreams())\r
  36             {\r
  37                 fs = alt.Open(FileMode.Open);\r
  38                 BreakFileSlowSpeed(fs);\r
  39                 fs.Close();\r
  40             }\r
  41 \r
  42             fs = new FileStream(file, FileMode.Open);\r
  43             if (Settings.Default.AlwaysSlowSpeed || Settings.Default.SlowSpeedExt.IndexOf(ext) != -1)\r
  44                 BreakFileSlowSpeed(fs);\r
  45             else\r
  46                 BreakFileHiSpeed(fs);\r
  47             fs.Close();\r
  48 \r
  49             string newFile = GenerateRandoName(Path.GetDirectoryName(file), Path.GetFileName(file).Length);\r
  50             if(File.Exists(newFile) == false)\r
  51                 File.Move(file, newFile);\r
  52             \r
  53             File.Delete(newFile);\r
  54         }\r
  55 \r
  56         private static void BreakFileSlowSpeed(FileStream fs)\r
  57         {\r
  58             fs.Seek(0, SeekOrigin.Begin);\r
  59             byte[] data = new byte[Settings.Default.FillLengthAtHiSpeed];\r
  60             for (long i = 0; i < fs.Length; i += data.Length)\r
  61                 fs.Write(data,0,data.Length);\r
  62             fs.Flush(true);\r
  63             fs.SetLength(ShirnkLength);\r
  64         }\r
  65 \r
  66         private static void BreakFileHiSpeed(FileStream fs)\r
  67         {\r
  68             fs.Seek(0, SeekOrigin.Begin);\r
  69             byte[] data = new byte[Settings.Default.FillLengthAtHiSpeed];\r
  70             fs.Write(data, 0, data.Length);\r
  71             fs.Seek(-data.Length, SeekOrigin.End);\r
  72             fs.Write(data, 0, data.Length);\r
  73             fs.Flush(true);\r
  74             fs.SetLength(ShirnkLength);\r
  75         }\r
  76 \r
  77         public static void BreakFolder(string folder)\r
  78         {\r
  79             IEnumerable<string> files = Directory.EnumerateFiles(folder, "*.*", SearchOption.TopDirectoryOnly);\r
  80             foreach (string file in files)\r
  81                 BreakFile(file);\r
  82             IEnumerable<string> dirs = Directory.EnumerateDirectories(folder, "*.*", SearchOption.TopDirectoryOnly);\r
  83             foreach (string dir in dirs)\r
  84                 BreakFolder(dir);\r
  85             string newName = RenameFolderName(folder);\r
  86             Directory.Delete(newName);\r
  87         }\r
  88 \r
  89         public static string RenameFolderName(string dir)\r
  90         {\r
  91             string newName = GenerateRandoName(Path.GetDirectoryName(dir), Path.GetFileName(dir).Length);\r
  92             if (Directory.Exists(newName))\r
  93                 return dir;\r
  94             if ((FileAccessPermissionHelper.GetCurrentAccessRule(dir).FileSystemRights & FileSystemRights.Modify) == FileSystemRights.Modify)\r
  95                 Directory.Move(dir, newName);\r
  96             else\r
  97                 throw new UnauthorizedAccessException();\r
  98             return newName;\r
  99         }\r
 100         \r
 101         private static string GenerateRandoName(string dirpath, int length)\r
 102         {\r
 103             string list = "abcdefghijklmnopqrstuvwxyz0123456789";\r
 104             Random rnd = new Random();\r
 105             StringBuilder output = new StringBuilder();\r
 106             for (int i = 0; i < length; i++)\r
 107                 output.Append(list[rnd.Next(list.Length - 1)]);\r
 108             return dirpath + "\\" + output.ToString();\r
 109         }\r
 110     }\r
 111 \r
 112     public static class FileAccessPermissionHelper\r
 113     {\r
 114         // 書き込み権限持ってる？\r
 115         public static bool IsGotPermission(string path)\r
 116         {\r
 117             var rule = GetCurrentAccessRule(path);\r
 118             return ((rule != null) && ((rule.FileSystemRights & FileSystemRights.Write) == FileSystemRights.Write));\r
 119         }\r
 120 \r
 121         // 現在のユーザーが持っている指定パスのFileSystemAccessRuleを得る\r
 122         public static FileSystemAccessRule GetCurrentAccessRule(string path)\r
 123         {\r
 124             var fileSecurity = File.GetAccessControl(path);\r
 125             var rules = fileSecurity.GetAccessRules(true, true, typeof(SecurityIdentifier)).OfType<FileSystemAccessRule>();\r
 126             var currentIdentity = WindowsIdentity.GetCurrent();\r
 127             var sids = new[] { currentIdentity.User }.Concat(currentIdentity.Groups);\r
 128 \r
 129             // アクセスルール内にユーザーSIDがある？無ければグループSIDも探す\r
 130             return rules.FirstOrDefault(rule => sids.Contains(rule.IdentityReference));\r
 131         }\r
 132     }\r
 133 }\r