reactos/lib/rtl/encode.c

   1 /* $Id$
   2  *
   3  * COPYRIGHT:         See COPYING in the top level directory
   4  * PROJECT:           ReactOS kernel
   5  * PURPOSE:           Security descriptor functions
   6  * FILE:              lib/rtl/encode.c
   7  * PROGRAMMER:        KJK::Hyperion <noog@libero.it>
   8  * REVISION HISTORY:
   9  *                 02/04/2003: created (code contributed by crazylord
  10  *                             <crazyl0rd@minithins.net>)
  11  */
  12
  13 /* INCLUDES *****************************************************************/
  14
  15 #include <ddk/ntddk.h>
  16
  17 #include <ntdll/ntdll.h>
  18
  19 /* FUNCTIONS ***************************************************************/
  20
  21 VOID STDCALL
  22 RtlRunDecodeUnicodeString (IN UCHAR Hash,
  23                            IN OUT PUNICODE_STRING String)
  24 {
  25    PUCHAR ptr;
  26    USHORT i;
  27
  28    ptr = (PUCHAR)String->Buffer;
  29    if (String->Length > 1)
  30    {
  31       for (i = String->Length; i > 1; i--)
  32       {
  33          ptr[i - 1] ^= ptr[i - 2] ^ Hash;
  34       }
  35    }
  36
  37    if (String->Length >= 1)
  38    {
  39       ptr[0] ^= Hash | (UCHAR)0x43;
  40    }
  41 }
  42
  43
  44 VOID STDCALL
  45 RtlRunEncodeUnicodeString (IN OUT PUCHAR Hash,
  46                            IN OUT PUNICODE_STRING String)
  47 {
  48    LARGE_INTEGER CurrentTime;
  49    PUCHAR ptr;
  50    USHORT i;
  51    NTSTATUS Status;
  52
  53    ptr = (PUCHAR) String->Buffer;
  54    if (*Hash == 0)
  55    {
  56       Status = NtQuerySystemTime (&CurrentTime);
  57       if (NT_SUCCESS(Status))
  58       {
  59          for (i = 1; i < sizeof(LARGE_INTEGER) && (*Hash == 0); i++)
  60             *Hash |= *(PUCHAR)(((PUCHAR)&CurrentTime) + i);
  61       }
  62
  63       if (*Hash == 0)
  64          *Hash = 1;
  65    }
  66
  67    if (String->Length >= 1)
  68    {
  69       ptr[0] ^= (*Hash) | (UCHAR)0x43;
  70       if (String->Length > 1)
  71       {
  72          for (i = 1; i < String->Length; i++)
  73          {
  74             ptr[i] ^= ptr[i - 1] ^ (*Hash);
  75          }
  76       }
  77    }
  78 }
  79
  80 /* EOF */