Markus Armbruster
9102ecce54
We seed it with value of time(). It's the traditional way, but it
provides only a few bits of effective entropy when an attacker has a
rough idea when the program started.
Instead, seed with a kernel random number. If we can't get one, fall
back to a hash of gettimeofday() and getpid(). This should happen
only on old systems or Windows. Far worse than a kernel random
number, but far better than using time().
Note that fairland used to seed with time() + getpid() until commit
331aac2a (v4.2.20) dropped the getpid(), claiming it didn't improve
the randomness. Perhaps it didn't under Windows then, but it
certainly did elsewhere, so it was a regression.
44 lines
1.4 KiB
C
44 lines
1.4 KiB
C
/*
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* Empire - A multi-player, client/server Internet based war game.
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* Copyright (C) 1986-2012, Dave Pare, Jeff Bailey, Thomas Ruschak,
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* Ken Stevens, Steve McClure, Markus Armbruster
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*
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* Empire is free software: you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*
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* ---
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*
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* See files README, COPYING and CREDITS in the root of the source
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* tree for related information and legal notices. It is expected
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* that future projects/authors will amend these files as needed.
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*
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* ---
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*
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* chance.h: Roll dice
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*
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* Known contributors to this file:
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* Markus Armbruster, 2012
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*/
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#ifndef CHANCE_H
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#define CHANCE_H
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extern int chance(double);
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extern int pct_chance(int);
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extern int roll0(int);
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extern int roll(int);
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extern int roundavg(double);
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extern void seed_prng(unsigned);
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extern unsigned pick_seed(void);
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#endif
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