Nmap Development mailing list archives
Re: [Bug]? -iR <num_hosts> on windows XP generates duplicate targets
From: doug () hcsw org
Date: Thu, 1 May 2008 22:25:53 -0700
On Fri, May 02, 2008 at 03:53:47AM +0000 or thereabouts, Brandon Enright wrote:
I did the same. I was not able to run -iR 5000 even with hours of waiting. I love Linux but this really is the fault of the kernel developers not recognizing the problem or accepting patches to "fix" /dev/random. Yarrow, Fortuna, and other RNG schemes have been coded up but haven't been integrated.
No, IMO this is not a kernel problem. /dev/random (or /dev/srandom on oBSD) MUST block if it doesn't have enough entropy in the pool. For example, when you are creating a GPG key and it tells you to wave your mouse around or whatever, it is doing this to ensure that you will get a key that is not predictable, even if an attacker knows exactly when your system was booted, all PIDs of processes on your system, and even has a long sequence of random numbers generated by your system earlier. All PRNGs have to be seeded. /dev/random ensures that your seeds really will be unpredictable and will never give you random data that hasn't been gathered from the "real world". If you can't take the blocking, well, that's what arandom/urandom are for. Remember netscape in 95? They seeded their PRNG with the PID, the PPID, and the time, all MD5ed, and it still wasn't good enough: http://www.cs.berkeley.edu/~daw/papers/ddj-netscape.html Doug
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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 Thomas Buchanan (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 jah (Apr 24)
- Re: [Bug]? -iR <num_hosts> on windows XP generates duplicate targets Brandon Enright (Apr 30)
- Re: [Bug]? -iR <num_hosts> on windows XP generates duplicate targets jah (Apr 30)
- Re: [Bug]? -iR <num_hosts> on windows XP generates duplicate targets David Fifield (Apr 30)
- Re: [Bug]? -iR <num_hosts> on windows XP generates duplicate targets Brandon Enright (Apr 30)
- 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 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)