Openwall GNU/*/Linux - a small security-enhanced Linux distro for servers
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date: Thu, 18 Oct 2012 10:22:29 +0530
From: Dhiru Kholia <dhiru.kholia@...il.com>
To: john-dev@...ts.openwall.com
Subject: Re: Re: long-running program on bull (was: council)

On Thu, Oct 18, 2012 at 4:08 AM, magnum <john.magnum@...hmail.com> wrote:
> On 14 Oct, 2012, at 10:54 , Dhiru Kholia <dhiru.kholia@...il.com> wrote:
>> This program guarantees decryption of office documents which are using RC4 40-bit encryption. Its priority can be lowered if required.
>>
>> For some reason, this program doesn't run on Solar's 8-core Xeon machine when OMP is enabled.
>
> It crashed for me too, until I moved the #pragma up a couple of levels:
>
> diff --git a/RC4-40-brute.c b/RC4-40-brute.c
> index 30071e0..d1fcd42 100755
> --- a/RC4-40-brute.c
> +++ b/RC4-40-brute.c
> @@ -102,7 +102,7 @@ void keyspace_search()
>         struct timeval tv;
>         time_t curtime;
>
> -       int i, j, k, l, m;
> +       int i, j, k;
>         /* 69a3aea22c is key for test.doc */
>         int is = 0x00;
>         int js = 0x00;
> @@ -124,11 +124,12 @@ void keyspace_search()
>                         curtime=tv.tv_sec;
>                         printf("%d %d @ ", i, j);
>                         strftime(buffer,30,"%m-%d-%Y  %T.",localtime(&curtime));
> -                       printf("%s%ld\n",buffer,tv.tv_usec);
> +                       printf("%s%ld\n", buffer, (long)tv.tv_usec);
>                         fflush(stdout);
> +#pragma omp parallel for
>                         for(k = ks; k <= 255; k++) {
> +                               int l, m;
>                                 for(l = ls; l <= 255; l++) {
> -#pragma omp parallel for
>                                         for(m = ms; m <= 255; m++) {
>                                                 unsigned char hashBuf[9] = { 0 };
>                                                 hashBuf[0] = (char)i;
>
>
> Not sure why really.

Maybe Solar can answer this one.

> So what would you do with a cracked key? Is there any free program that can use this RC4 key to unlock a document?

Sadly, I couldn't find any program which can do this. I wrote the
program for fun. Good luck with the OpenCL implementation.

I am working on a similar key brute-forcer for PDF files where the key
calculation is expensive (50 rounds of MD5). OpenCL implementation
will be useful there.

-- 
Cheers,
Dhiru

Powered by blists - more mailing lists

Your e-mail address:

Powered by Openwall GNU/*/Linux - Powered by OpenVZ