reactos/lib/rtl/encode.c

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