sdk/lib/rtl/encode.c

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