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 \r
  29             if ((attr & FileAttributes.ReadOnly) == FileAttributes.ReadOnly)\r
  30                 File.SetAttributes(file, attr & ~FileAttributes.ReadOnly);\r
  31 \r
  32             if ((attr & FileAttributes.ReparsePoint) != FileAttributes.ReparsePoint &&\r
  33                 (attr & FileAttributes.SparseFile) != FileAttributes.SparseFile)\r
  34                 FillFileContent(file);\r
  35             \r
  36             string newFile = GenerateRandoName(Path.GetDirectoryName(file), Path.GetFileName(file).Length);\r
  37             if(File.Exists(newFile) == false)\r
  38                 File.Move(file, newFile);\r
  39             \r
  40             File.Delete(newFile);\r
  41         }\r
  42 \r
  43         private static void FillFileContent(string file)\r
  44         {\r
  45             FileStream fs;\r
  46             FileInfo info = new FileInfo(file);\r
  47 \r
  48             foreach (AlternateDataStreamInfo alt in info.ListAlternateDataStreams())\r
  49             {\r
  50                 fs = alt.Open(FileMode.Open);\r
  51                 BreakFileSlowSpeed(fs);\r
  52                 fs.Close();\r
  53             }\r
  54 \r
  55             string ext = Path.GetExtension(file);\r
  56 \r
  57             fs = new FileStream(file, FileMode.Open, FileAccess.Write, FileShare.None, 8, FileOptions.WriteThrough);\r
  58             if (Settings.Default.AlwaysSlowSpeed || Settings.Default.SlowSpeedExt.IndexOf(ext) != -1)\r
  59                 BreakFileSlowSpeed(fs);\r
  60             else\r
  61                 BreakFileHiSpeed(fs);\r
  62             fs.Close();\r
  63         }\r
  64 \r
  65         private static void BreakFileSlowSpeed(FileStream fs)\r
  66         {\r
  67             fs.Seek(0, SeekOrigin.Begin);\r
  68             byte[] data = new byte[Settings.Default.FillLengthAtHiSpeed];\r
  69             for (long i = 0; i < fs.Length; i += data.Length)\r
  70                 fs.Write(data,0,data.Length);\r
  71             fs.Flush(true);\r
  72             fs.SetLength(ShirnkLength);\r
  73         }\r
  74 \r
  75         private static void BreakFileHiSpeed(FileStream fs)\r
  76         {\r
  77             fs.Seek(0, SeekOrigin.Begin);\r
  78             byte[] data = new byte[Settings.Default.FillLengthAtHiSpeed];\r
  79             fs.Write(data, 0, data.Length);\r
  80             fs.Seek(-data.Length, SeekOrigin.End);\r
  81             fs.Write(data, 0, data.Length);\r
  82             fs.Flush(true);\r
  83             fs.SetLength(ShirnkLength);\r
  84         }\r
  85 \r
  86         public static void BreakFolder(string folder)\r
  87         {\r
  88             DirectoryInfo info = new DirectoryInfo(folder);\r
  89             if ((info.Attributes & FileAttributes.ReparsePoint) != FileAttributes.ReparsePoint)\r
  90             {\r
  91                 IEnumerable<string> files = Directory.EnumerateFiles(folder, "*.*", SearchOption.TopDirectoryOnly);\r
  92                 foreach (string file in files)\r
  93                     BreakFile(file);\r
  94                 IEnumerable<string> dirs = Directory.EnumerateDirectories(folder, "*.*", SearchOption.TopDirectoryOnly);\r
  95                 foreach (string dir in dirs)\r
  96                     BreakFolder(dir);\r
  97             }\r
  98             string newName = RenameFolderName(folder);\r
  99             Directory.Delete(newName);\r
 100         }\r
 101 \r
 102         public static string RenameFolderName(string dir)\r
 103         {\r
 104             string newName = GenerateRandoName(Path.GetDirectoryName(dir), Path.GetFileName(dir).Length);\r
 105             if (Directory.Exists(newName))\r
 106                 return dir;\r
 107             if ((FileAccessPermissionHelper.GetCurrentAccessRule(dir).FileSystemRights & FileSystemRights.Modify) == FileSystemRights.Modify)\r
 108                 Directory.Move(dir, newName);\r
 109             else\r
 110                 throw new UnauthorizedAccessException();\r
 111             return newName;\r
 112         }\r
 113         \r
 114         private static string GenerateRandoName(string dirpath, int length)\r
 115         {\r
 116             string list = "abcdefghijklmnopqrstuvwxyz0123456789";\r
 117             Random rnd = new Random();\r
 118             StringBuilder output = new StringBuilder();\r
 119             for (int i = 0; i < length; i++)\r
 120                 output.Append(list[rnd.Next(list.Length - 1)]);\r
 121             return dirpath + "\\" + output.ToString();\r
 122         }\r
 123     }\r
 124 \r
 125     public static class FileAccessPermissionHelper\r
 126     {\r
 127         // 書き込み権限持ってる？\r
 128         public static bool IsGotPermission(string path)\r
 129         {\r
 130             var rule = GetCurrentAccessRule(path);\r
 131             return ((rule != null) && ((rule.FileSystemRights & FileSystemRights.Write) == FileSystemRights.Write));\r
 132         }\r
 133 \r
 134         // 現在のユーザーが持っている指定パスのFileSystemAccessRuleを得る\r
 135         public static FileSystemAccessRule GetCurrentAccessRule(string path)\r
 136         {\r
 137             var fileSecurity = File.GetAccessControl(path);\r
 138             var rules = fileSecurity.GetAccessRules(true, true, typeof(SecurityIdentifier)).OfType<FileSystemAccessRule>();\r
 139             var currentIdentity = WindowsIdentity.GetCurrent();\r
 140             var sids = new[] { currentIdentity.User }.Concat(currentIdentity.Groups);\r
 141 \r
 142             // 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
 143             return rules.FirstOrDefault(rule => sids.Contains(rule.IdentityReference));\r
 144         }\r
 145     }\r
 146 }\r