internal static void ImportEncryptedFileRawCore(System.IO.Stream inputStream, string destinationFilePath, PathFormat pathFormat, NativeMethods.EncryptedFileRawMode mode)
{
string lpPath = Path.GetExtendedLengthPathCore(null, destinationFilePath, pathFormat, GetFullPathOptions.FullCheck | GetFullPathOptions.TrimEnd);
SafeEncryptedFileRawHandle context = null;
int errorCode = NativeMethods.OpenEncryptedFileRaw(lpPath, mode, out context);
try
{
if (errorCode != Win32Errors.ERROR_SUCCESS)
{
NativeError.ThrowException(errorCode, null, destinationFilePath);
}
errorCode = NativeMethods.WriteEncryptedFileRaw((IntPtr pbData, IntPtr pvCallbackContext, ref uint ulLength) =>
{
try
{
byte[] buffer = new byte[ulLength];
ulLength = (uint)inputStream.Read(buffer, 0, (int)ulLength);
if (ulLength == 0)
{
return((int)Win32Errors.ERROR_SUCCESS);
}
Marshal.Copy(buffer, 0, pbData, (int)ulLength);
}
catch (Exception ex)
{
return(Marshal.GetHRForException(ex));
}
return((int)Win32Errors.ERROR_SUCCESS);
}, IntPtr.Zero, context);
if (errorCode != Win32Errors.ERROR_SUCCESS)
{
NativeError.ThrowException(errorCode, null, destinationFilePath);
}
}
finally
{
if (context != null)
{
context.Dispose();
}
}
}
/// <summary>
/// Backs up (export) encrypted files. This is one of a group of Encrypted File System (EFS) functions that is
/// intended to implement backup and restore functionality, while maintaining files in their encrypted state.
/// </summary>
/// <remarks>
/// <para>
/// The file being backed up is not decrypted; it is backed up in its encrypted state.
/// </para>
/// <para>
/// If the caller does not have access to the key for the file, the caller needs
/// <see cref="Alphaleonis.Win32.Security.Privilege.Backup"/> to export encrypted files. See
/// <see cref="Alphaleonis.Win32.Security.PrivilegeEnabler"/>.
/// </para>
/// <para>
/// To backup an encrypted file call one of the
/// <see cref="O:Alphaleonis.Win32.Filesystem.File.ExportEncryptedFileRaw"/> overloads and specify the file to backup
/// along with the destination stream of the backup data.
/// </para>
/// <para>
/// This function is intended for the backup of only encrypted files; see <see cref="BackupFileStream"/> for backup
/// of unencrypted files.
/// </para>
/// </remarks>
/// <param name="fileName">The name of the file to be backed up.</param>
/// <param name="output">The destination stream to which the backup data will be written.</param>
/// <param name="pathFormat">The path format of the <paramref name="fileName"/> parameter.</param>
/// <seealso cref="O:Alphaleonis.Win32.Filesystem.File.ImportEncryptedFileRaw"/>
public static void ExportEncryptedFileRaw(string fileName, System.IO.Stream output, PathFormat pathFormat)
{
string lpPath = Path.GetExtendedLengthPathCore(null, fileName, pathFormat, GetFullPathOptions.FullCheck | GetFullPathOptions.TrimEnd);
SafeEncryptedFileRawHandle context = null;
int errorCode = NativeMethods.OpenEncryptedFileRaw(lpPath, NativeMethods.EncryptedFileRawMode.CreateForExport, out context);
try
{
if (errorCode != Win32Errors.ERROR_SUCCESS)
{
NativeError.ThrowException(errorCode, fileName);
}
errorCode = NativeMethods.ReadEncryptedFileRaw((IntPtr pbData, IntPtr pvCallbackContext, uint ulLength) =>
{
try
{
byte[] data = new byte[ulLength];
Marshal.Copy(pbData, data, 0, (int)ulLength);
output.Write(data, 0, (int)ulLength);
}
catch (Exception ex)
{
return(Marshal.GetHRForException(ex));
}
return((int)Win32Errors.ERROR_SUCCESS);
}, IntPtr.Zero, context);
if (errorCode != Win32Errors.ERROR_SUCCESS)
{
NativeError.ThrowException(errorCode, fileName);
}
}
finally
{
if (context != null)
{
context.Dispose();
}
}
}
internal static extern int WriteEncryptedFileRaw([MarshalAs(UnmanagedType.FunctionPtr)] EncryptedFileRawImportCallback pfExportCallback, IntPtr pvCallbackContext, SafeEncryptedFileRawHandle pvContext);
internal static extern int OpenEncryptedFileRaw([MarshalAs(UnmanagedType.LPWStr)] string lpFileName, EncryptedFileRawMode ulFlags, out SafeEncryptedFileRawHandle pvContext);
public static extern int OpenEncryptedFileRaw(string lpFileName, EncryptedFileRawMode ulFlags, out SafeEncryptedFileRawHandle pvContext);