Nmap Development mailing list archives
Re: [Bug]? -iR <num_hosts> on windows XP generates duplicate targets
From: Kris Katterjohn <katterjohn () gmail com>
Date: Thu, 01 May 2008 21:33:18 -0500
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Brandon Enright wrote:
Finally, one thing that hasn't been addressed in this patch is that on *nix, Nmap first tries "arandom" and then "urandom" before trying "random". If a box doesn't offer [au]random but does offer random Nmap will block -- /dev/random doesn't provide randomness as fast as Nmap uses it. The use of /dev/random should be dropped in favor of falling back on rand() or in the future, OpenSSL.
Per your suggestion of OpenSSL, this is a 4.20ALPHA4 CHANGELOG entry: o Nmap no longer gets random numbers from OpenSSL when it is available because that turned out to be slower than Nmap's other methods (e.g. /dev/urandom on Linux, /dev/arandom on OpenBSD, etc.). Thanks to Marek Majkowski for reporting the problem. WRT to the /dev/random hanging, I see what you mean! I edited nbase_rnd.c and Nmap immediately hangs and strace confirms it's from a read(/dev/random). But what are the odds of you mentioning this hanging so soon after this (bit hostile) email[1] which mentions the exact behavior Nmap exhibits when I only use /dev/random? Apparently his Linux box doesn't have urandom (or it's a very strange coincidence since I've never had Nmap just hang immediately for any other reason..) Given the options of /dev/random, rand() and OpenSSL, it looks like rand() may be the answer since random hangs and OpenSSL was slow. Good find.
Brandon
Thanks, Kris Katterjohn [1] http://seclists.org/nmap-dev/2008/q2/0182.html -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.6 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iQIVAwUBSBp9bP9K37xXYl36AQJZlw//SqWLbYIDbo+AWSobExn3WwVYIohGhrQE YGZfmN3s6Of2AyjOjsPlUT1pPy4as0/c2yhkFZOKRDsFepafncqJas+hRpPJKMK4 M8usGrlzK03saZ2Z2WNuQ7yt7Eia1EzAQTr7QA/dgfS+dwpgz0s1vHdf+Q+mi32I ziG5LkNwPLQKBussXwUZl++EjLoW/op5Klj030pXeOaU9KdEjSozT8S+xgbRgDPz gJJZEgvTiZ3JWXFnKcitBKeHqT6R9gdJFmhX/YJWQK48OzXG7cQNOpqx5YshC1r/ NVwjyGaTRZndB/YR5wEP9j9f3JK9XlrMlyrNfM+Smo7b0l3c+5Yd5qjQhim7rBgs 6ve/VLOL6yFthbqDpaBTZwRIg0gd5+RCJm4RUixX7o8ehbiLMchgAVqgGZZdAEdC lQCvo0/vpYEJ8EyhIIJGGrcQLqcAPGsO6OYA6VwSVhYdHSMbsBRy1sWhkqSBI0XI s6UozLVj2U0WCT+DJrguY0uBtedBpzJ9pnQMi8+MFsEztGJ0ZzIh2TYALD5+jI9+ HEMZFXtY4jzQCkS7EvQH36lJQ6GHs/J4EJVrb9A5kVltQnWr8KQ3OUrPoJFx8/hU oGnrW/ptSQd1EIWV6F79qI5OZOgI5aN5EYtk7UBsNgrTs/M7nEP4EiTchSVYkaXZ vgO6I3LwSyQ= =C4fh -----END PGP SIGNATURE----- _______________________________________________ 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 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 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)