+++ /dev/null
-/* -*-c-*-
- *
- * $Id: noise.h,v 1.6 2004/04/08 01:36:15 mdw Exp $
- *
- * Acquisition of environmental noise (Unix-specific)
- *
- * (c) 1998 Straylight/Edgeware
- */
-
-/*----- Licensing notice --------------------------------------------------*
- *
- * This file is part of Catacomb.
- *
- * Catacomb is free software; you can redistribute it and/or modify
- * it under the terms of the GNU Library General Public License as
- * published by the Free Software Foundation; either version 2 of the
- * License, or (at your option) any later version.
- *
- * Catacomb is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU Library General Public License for more details.
- *
- * You should have received a copy of the GNU Library General Public
- * License along with Catacomb; if not, write to the Free
- * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
- * MA 02111-1307, USA.
- */
-
-#ifndef CATACOMB_NOISE_H
-#define CATACOMB_NOISE_H
-
-#ifdef __cplusplus
- extern "C" {
-#endif
-
-/*----- Header files ------------------------------------------------------*/
-
-#include <sys/types.h>
-
-#ifndef CATACOMB_RAND_H
-# include "rand.h"
-#endif
-
-/*----- Noise source definition -------------------------------------------*/
-
-extern const rand_source noise_source;
-
-/*----- Magic numbers -----------------------------------------------------*/
-
-#define NOISE_NOSETUID ((uid_t)-1)
-#define NOISE_NOSETGID ((gid_t)-1)
-
-/*----- Functions provided ------------------------------------------------*/
-
-/* --- @noise_timer@ --- *
- *
- * Arguments: @rand_pool *r@ = pointer to a randomness pool
- *
- * Returns: Nonzero if some randomness was contributed.
- *
- * Use: Contributes the current time to the randomness pool.
- * A guess at the number of useful bits contributed is made,
- * based on first and second order bit differences. This isn't
- * ever-so reliable, but it's better than nothing.
- */
-
-extern int noise_timer(rand_pool */*r*/);
-
-/* --- @noise_devrandom@ --- *
- *
- * Arguments: @rand_pool *r@ = pointer to a randomness pool
- *
- * Returns: Nonzero if some randomness was contributed.
- *
- * Use: Attempts to obtain some randomness from the system entropy
- * pool. All bits from the device are assumed to be good.
- */
-
-extern int noise_devrandom(rand_pool */*r*/);
-
-/* --- @noise_setid@ --- *
- *
- * Arguments: @uid_t uid@ = uid to set
- * @gid_t gid@ = gid to set
- *
- * Returns: ---
- *
- * Use: Sets the user and group ids to be used by @noise_filter@
- * when running child processes. This is useful to avoid
- * giving shell commands (even carefully written ones) undue
- * privileges. This interface is Unix-specific.
- */
-
-extern void noise_setid(uid_t /*uid*/, gid_t /*gid*/);
-
-/* --- @noise_filter@ --- *
- *
- * Arguments: @rand_pool *r@ = pointer to a randomness pool
- * @int good@ = number of good bits per 1024 bits
- * @const char *c@ = shell command to run
- *
- * Returns: Nonzero if some randomness was contributed.
- *
- * Use: Attempts to execute a shell command, and dump it into the
- * randomness pool. A very rough estimate of the number of
- * good bits is made, based on the size of the command's output.
- * This function calls @waitpid@, so be careful. Before execing
- * the command, the process uid and gid are set to the values
- * given to @noise_setid@, and an attempt is made to reset the
- * list of supplementary groups. The environment passed to
- * the command has been severly lobotimized. If the command
- * fails to complete within a short time period, it is killed.
- * Paranoid use of close-on-exec flags for file descriptors is
- * recommended.
- *
- * This interface is Unix-specific.
- */
-
-extern int noise_filter(rand_pool */*r*/, int /*good*/, const char */*c*/);
-
-/* --- @noise_freewheel@ --- *
- *
- * Arguments: @rand_pool *r@ = pointer to a randomness pool
- *
- * Returns: Nonzero if some randomness was contributed.
- *
- * Use: Runs a free counter for a short while as a desparate attempt
- * to get randomness from somewhere. This is actually quite
- * effective.
- */
-
-int noise_freewheel(rand_pool */*r*/);
-
-/* --- @noise_enquire@ --- *
- *
- * Arguments: @rand_pool *r@ = pointer to a randomness pool
- *
- * Returns: Nonzero if some randomness was contributed.
- *
- * Use: Runs some shell commands to enquire about the prevailing
- * environment. This can gather quite a lot of low-quality
- * entropy.
- */
-
-extern int noise_enquire(rand_pool */*r*/);
-
-/* --- @noise_acquire@ --- *
- *
- * Arguments: @rand_pool *r@ = pointer to a randomness pool
- *
- * Returns: ---
- *
- * Use: Acquires some randomness from somewhere.
- */
-
-extern void noise_acquire(rand_pool */*r*/);
-
-/*----- That's all, folks -------------------------------------------------*/
-
-#ifdef __cplusplus
- }
-#endif
-
-#endif
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