sdk/lib/cmlib/hivesum.c

   1 /*
   2  * PROJECT:   Registry manipulation library
   3  * LICENSE:   GPL - See COPYING in the top level directory
   4  * COPYRIGHT: Copyright 2005 Filip Navara <navaraf@reactos.org>
   5  *            Copyright 2001 - 2005 Eric Kohl
   6  */
   7
   8 #include "cmlib.h"
   9
  10 /**
  11  * @name HvpHiveHeaderChecksum
  12  *
  13  * Compute checksum of hive header and return it.
  14  */
  15
  16 ULONG CMAPI
  17 HvpHiveHeaderChecksum(
  18     PHBASE_BLOCK HiveHeader)
  19 {
  20     PULONG Buffer = (PULONG)HiveHeader;
  21     ULONG Sum = 0;
  22     ULONG i;
  23
  24     for (i = 0; i < 127; i++)
  25         Sum ^= Buffer[i];
  26     if (Sum == (ULONG)-1)
  27         Sum = (ULONG)-2;
  28     if (Sum == 0)
  29         Sum = 1;
  30
  31     return Sum;
  32 }