Nmap Development mailing list archives
Re: Performance thoughts
From: Diman Todorov <diman () xover mud at>
Date: Wed, 5 Jul 2006 01:06:30 +0200
Interesting. We assumed that the OpenSSL random number generator would be better and so we use that if it is available. But it sounds like it isn't as efficient as using Linux's /dev/urandom . I'll remove that (openssh random number) functionality for ALPHA3. 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.
Yes /dev/urandom should perform better but it is not really random. I have run into problems with it's short period before. A look at the mersenne twister at http://www.math.sci.hiroshima- u.ac.jp/~m-mat/MT/emt.html might be a good idea. They provide c code for the random number generator although I don't know how well it performs compared to openssl and /dev/urandom I have used their code to draw random samples of 5k from datasets of 10bio samples which worked ok. cheers Diman _______________________________________________ Sent through the nmap-dev mailing list http://cgi.insecure.org/mailman/listinfo/nmap-dev
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- Performance thoughts majek04 (Jul 03)
- Re: Performance thoughts Fyodor (Jul 04)
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- Re: Performance thoughts Fyodor (Jul 04)
- Re: Performance thoughts majek04 (Jul 04)
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- Re: Performance thoughts Diman Todorov (Jul 04)
- Re: Performance thoughts Fyodor (Jul 04)
- Re: Performance thoughts Fyodor (Jul 04)