Nmap Development mailing list archives
Re: [Bug]? -iR <num_hosts> on windows XP generates duplicate targets
From: Fyodor <fyodor () insecure org>
Date: Wed, 23 Apr 2008 20:05:39 -0700
On Thu, Apr 24, 2008 at 01:54:45AM +0000, Brandon Enright wrote:
The problem here is that the rng is being seeded with time every time it is called.
I don't think it is. Here is the code with more context: if (badrandomwarning == 0) { badrandomwarning++; /* error("WARNING: your system apparently does not offer /dev/urandom or /dev/random. Reverting to less secure version."); */ /* Seed our random generator */ gettimeofday(&tv, NULL); srand((tv.tv_sec ^ tv.tv_usec) ^ getpid()); } badrandomwarning is a static variable. So this block should only be called once. And when I uncomment the error message, I indeed only see it printed once. HOWEVER, removing the srand() does seem to fix the issue on Windows. But I'm not really included to do that unless we have to, because I'd rather the library not require that of callers. I just tried removing the /dev/random stuff on Linux, and Linux still seems to generate good IPs using the same srand()/rand() code. So it may be something specific to Windows or maybe their srand()/rand() implementation. I've only had a few minutes to look at this, but it isn't clear what the problem is. Cheers, -F _______________________________________________ Sent through the nmap-dev mailing list http://cgi.insecure.org/mailman/listinfo/nmap-dev Archived at http://SecLists.Org
Current thread:
- Re: [Bug]? -iR <num_hosts> on windows XP generates duplicate targets, (continued)
- Re: [Bug]? -iR <num_hosts> on windows XP generates duplicate targets Brandon Enright (May 01)
- Re: [Bug]? -iR <num_hosts> on windows XP generates duplicate targets Kris Katterjohn (May 01)
- Re: [Bug]? -iR <num_hosts> on windows XP generates duplicate targets doug (May 01)
- Re: [Bug]? -iR <num_hosts> on windows XP generates duplicate targets Brandon Enright (May 01)
- Re: [Bug]? -iR <num_hosts> on windows XP generates duplicate targets doug (May 01)
- Re: [Bug]? -iR <num_hosts> on windows XP generates duplicate targets doug (May 01)
- Re: [Bug]? -iR <num_hosts> on windows XP generates duplicate targets doug (May 01)
- Re: [Bug]? -iR <num_hosts> on windows XP generates duplicate targets doug (May 01)
- Re: [Bug]? -iR <num_hosts> on windows XP generates duplicate targets Fyodor (May 02)
- Re: [Bug]? -iR <num_hosts> on windows XP generates duplicate targets jah (Apr 23)
- Re: [Bug]? -iR <num_hosts> on windows XP generates duplicate targets Fyodor (Apr 23)
- Re: [Bug]? -iR <num_hosts> on windows XP generates duplicate targets Brandon Enright (Apr 23)
- Re: [Bug]? -iR <num_hosts> on windows XP generates duplicate targets Fyodor (Apr 23)