clfs逆向3

__int64 __fastcall ClfsEncodeBlockPrivate(_CLFS_LOG_BLOCK_HEADER *hdr, unsigned int TotalSectorCount, char a3, unsigned __int8 a4)
{
  int TotalSectorCounNow; // eax
  unsigned __int8 val10; // bl
  unsigned int TotalSectorCountRef; // esi
  _CLFS_LOG_BLOCK_HEADER *that; // r10
  signed int v8; // ecx
  unsigned int SignaturesOffset; // ecx
  unsigned int SectorCount; // edi
  unsigned int SignaturesOffseEndRet; // ecx
  ULONG preflag; // er9
  _CLFS_LOG_BLOCK_HEADER *thisref; // r10
  __int64 SignaturesOffsetAddr; // r11
  unsigned int Sectoridx; // edx
  char flag1; // cl
  char flag2; // al
  char flagall; // cl
  __int64 sectorbase; // rax
  unsigned int SignaturesOffseEnd; // [rsp+20h] [rbp-18h]
  USHORT flagsig; // [rsp+40h] [rbp+8h]

  TotalSectorCounNow = hdr->TotalSectorCount;
  val10 = a4;
  TotalSectorCountRef = TotalSectorCount;
  SignaturesOffseEnd = 0;
  that = hdr;
  if ( !(_WORD)TotalSectorCounNow
    || hdr->ValidSectorCount < (unsigned __int16)TotalSectorCounNow
    || TotalSectorCounNow << 9 > TotalSectorCount )
  {
    return 0xC01A000Ai64;
  }
  if ( a4 > 0x10u )
    return 0xC000000Di64;
  v8 = 65809;
  if ( !_bittest(&v8, a4) )
    return 0xC000000Di64;
  if ( that->Flags & 1 )
    return 0xC01A000Ai64;
  SignaturesOffset = that->SignaturesOffset;
  SectorCount = TotalSectorCount >> 9;
  that->Usn = a3;
  HIBYTE(flagsig) = a3;
  if ( (signed int)ULongAdd(SignaturesOffset, 2 * (TotalSectorCount >> 9), &SignaturesOffseEnd) < 0
    || SignaturesOffseEnd < SignaturesOffseEndRet
    || SignaturesOffseEndRet & 7
    || SignaturesOffseEnd > TotalSectorCountRef )
  {
    return 0xC01A000Ai64;
  }
  Sectoridx = 0;
  if ( SectorCount )
  {
    do
    {
      // SignaturesOffsetAddr=(ULONGLONG)that+that->SignaturesOffset;
      SignaturesOffsetAddr += 2i64;
      flag1 = 0x20;
      flag2 = 0x40;
      if ( thisref->TotalSectorCount - 1 != Sectoridx )
        flag1 = 0;
      if ( Sectoridx )
        flag2 = 0;
      flagall = flag2 | flag1;
      sectorbase = Sectoridx << 9;
      LOBYTE(flagsig) = val10 | flagall;
      ++Sectoridx;
      //  signature array是个数组会和SignaturesOffset相交如果SignaturesOffset=0x50
      *(_WORD *)(SignaturesOffsetAddr - 2) = *(USHORT *)((char *)&thisref->sig + sectorbase);
      *(USHORT *)((char *)&thisref->sig + (unsigned int)sectorbase) = flagsig;
    }
    while ( Sectoridx < SectorCount );
    preflag = thisref->Flags;
  }
  thisref->Flags = preflag & 0xFFFFFFFD | 1;
  return 0i64;
}