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- /* Copyright (C) 2008-2016 Peter Palotas, Jeffrey Jangli, Alexandr Normuradov
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in
- * all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
- * THE SOFTWARE.
- */
-
- using System;
- using System.Globalization;
- using System.IO;
- using System.Runtime.InteropServices;
- using System.Security;
-
- namespace Alphaleonis.Win32.Filesystem
- {
- public static partial class File
- {
- #region Public Methods
-
- /// <summary>Decrypts a file that was encrypted by the current account using the Encrypt method.</summary>
- /// <param name="path">A path that describes a file to decrypt.</param>
- [SecurityCritical]
- public static void Decrypt(string path)
- {
- EncryptDecryptFileCore(false, path, false, PathFormat.RelativePath);
- }
-
- /// <summary>[AlphaFS] Decrypts a file that was encrypted by the current account using the Encrypt method.</summary>
- /// <param name="path">A path that describes a file to decrypt.</param>
- /// <param name="pathFormat">Indicates the format of the path parameter(s).</param>
- [SecurityCritical]
- public static void Decrypt(string path, PathFormat pathFormat)
- {
- EncryptDecryptFileCore(false, path, false, pathFormat);
- }
-
- /// <summary>Encrypts a file so that only the account used to encrypt the file can decrypt it.</summary>
- /// <param name="path">A path that describes a file to encrypt.</param>
- [SecurityCritical]
- public static void Encrypt(string path)
- {
- EncryptDecryptFileCore(false, path, true, PathFormat.RelativePath);
- }
-
- /// <summary>[AlphaFS] Encrypts a file so that only the account used to encrypt the file can decrypt it.</summary>
- /// <param name="path">A path that describes a file to encrypt.</param>
- /// <param name="pathFormat">Indicates the format of the path parameter(s).</param>
- [SecurityCritical]
- public static void Encrypt(string path, PathFormat pathFormat)
- {
- EncryptDecryptFileCore(false, path, true, pathFormat);
- }
-
- #endregion
-
-
-
-
- #region Internal Methods
-
- /// <summary>Decrypts/encrypts a file or directory so that only the account used to encrypt the file can decrypt it.</summary>
- /// <exception cref="NotSupportedException"/>
- /// <param name="isFolder">Specifies that <paramref name="path"/> is a file or directory.</param>
- /// <param name="path">A path that describes a file to encrypt.</param>
- /// <param name="encrypt"><see langword="true"/> encrypt, <see langword="false"/> decrypt.</param>
- /// <param name="pathFormat">Indicates the format of the path parameter(s).</param>
- [SecurityCritical]
- internal static void EncryptDecryptFileCore(bool isFolder, string path, bool encrypt, PathFormat pathFormat)
- {
- string pathLp = Path.GetExtendedLengthPathCore(null, path, pathFormat, GetFullPathOptions.RemoveTrailingDirectorySeparator | GetFullPathOptions.FullCheck);
-
- // Reset file/directory attributes.
- // MSDN: If lpFileName specifies a read-only file, the function fails and GetLastError returns ERROR_FILE_READ_ONLY.
- SetAttributesCore(isFolder, null, pathLp, FileAttributes.Normal, true, PathFormat.LongFullPath);
-
- // EncryptFile() / DecryptFile()
- // In the ANSI version of this function, the name is limited to 248 characters.
- // To extend this limit to 32,767 wide characters, call the Unicode version of the function and prepend "\\?\" to the path.
- // 2013-01-13: MSDN does not confirm LongPath usage but a Unicode version of this function exists.
-
- if (!(encrypt
- ? NativeMethods.EncryptFile(pathLp)
- : NativeMethods.DecryptFile(pathLp, 0)))
- {
- int lastError = Marshal.GetLastWin32Error();
- switch ((uint)lastError)
- {
- case Win32Errors.ERROR_ACCESS_DENIED:
- string root = Path.GetPathRoot(pathLp, false);
- if (!string.Equals("NTFS", new DriveInfo(root).DriveFormat, StringComparison.OrdinalIgnoreCase))
- throw new NotSupportedException(string.Format(CultureInfo.CurrentCulture, "The drive does not support NTFS encryption: [{0}]", root));
- break;
-
- default:
- if (lastError == Win32Errors.ERROR_FILE_NOT_FOUND && isFolder)
- lastError = (int)Win32Errors.ERROR_PATH_NOT_FOUND;
-
- NativeError.ThrowException(lastError, pathLp);
- break;
- }
- }
- }
-
- #endregion // Internal Methods
- }
- }
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