RtlStringFromGUIDEx

NTSTATUS __stdcall RtlStringFromGUIDEx(_GUID *Guid, _UNICODE_STRING *GuidString, UINT8 Allocate){
  wchar_t *StringRoutine; 
  unsigned __int16 MaximumLength; 

  if( Allocate )
  {
    GuidString->MaximumLength = 78;
    StringRoutine = (wchar_t *)ExpAllocateStringRoutine(0x4Eui64);
    GuidString->Buffer = StringRoutine;
    if( StringRoutine )
    {
      MaximumLength = GuidString->MaximumLength;
LABEL_4:
      GuidString->Length = 76;
      swprintf_s(
        GuidString->Buffer,
        (unsigned __int64)MaximumLength >> 1,
        (WCHAR *)L"{%08lx-%04x-%04x-%02x%02x-%02x%02x%02x%02x%02x%02x}",
        Guid->Data1,
        Guid->Data2,
        Guid->Data3,
        Guid->Data4[0],
        Guid->Data4[1],
        Guid->Data4[2],
        Guid->Data4[3],
        Guid->Data4[4],
        Guid->Data4[5],
        Guid->Data4[6],
        Guid->Data4[7]);
      return 0;
    }
    return -1073741801;
  }
  else
  {
    MaximumLength = GuidString->MaximumLength;
    if( MaximumLength >= 0x4Eu )
      goto LABEL_4;
    return -1073741789;
  }
}

Referenced by: