Re: ntdll: Randomize security cookie when available (try 4)

[Alexandre Julliard]

André Hentschel <nerv(a)dawncrow.de> writes:
> @@ -1278,6 +1281,26 @@ static NTSTATUS map_image( HANDLE hmapping, int fd, char *base, SIZE_T total_siz
>          }
>      }
>
> +
> +    /* randomize security cookie */
> +
> +    if (IMAGE_DIRECTORY_ENTRY_LOAD_CONFIG < nt->OptionalHeader.NumberOfRvaAndSizes &&
> +        (pos = nt->OptionalHeader.DataDirectory[IMAGE_DIRECTORY_ENTRY_LOAD_CONFIG].VirtualAddress))
> +    {
> +        IMAGE_LOAD_CONFIG_DIRECTORY *loadcfg = (IMAGE_LOAD_CONFIG_DIRECTORY *)(ptr + pos);
> +        ULONG_PTR *cookie = (ULONG_PTR *)loadcfg->SecurityCookie;
> +        struct timeval tv;
> +
> +        gettimeofday( &tv, NULL );
> +        srand( tv.tv_usec * getpid() );
> +        *cookie = rand();

That's not much better. It doesn't make sense to reset the seed on every
call.

-- 
Alexandre Julliard
julliard(a)winehq.org