mirror of
https://git.FreeBSD.org/src.git
synced 2024-12-19 10:53:58 +00:00
a6278a2a42
now in dirs called sys/*/random/ instead of sys/*/randomdev/*. Introduce blocking, but only at startup; the random device will block until the first reseed happens to prevent clients from using untrustworthy output. Provide a read_random() call for the rest of the kernel so that the entropy device does not need to be present. This means that things like IPX no longer need to have "device random" hardcoded into thir kernel config. The downside is that read_random() will provide very poor output until the entropy device is loaded and reseeded. It is recommended that developers do NOT use the read_random() call; instead, they should use arc4random() which internally uses read_random(). Clean up the mutex and locking code a bit; this makes it possible to unload the module again.
80 lines
3.0 KiB
C
80 lines
3.0 KiB
C
/*-
|
|
* Copyright (c) 2000 Mark R V Murray
|
|
* All rights reserved.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer
|
|
* in this position and unchanged.
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in the
|
|
* documentation and/or other materials provided with the distribution.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
|
|
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
|
|
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
|
|
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
|
|
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
|
|
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
|
|
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
|
|
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
|
|
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
|
|
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
|
*
|
|
* $FreeBSD$
|
|
*/
|
|
|
|
/* #define ENTROPYSOURCE nn entropy sources (actually classes)
|
|
* The entropy classes will as follows:
|
|
* 0 - Direct write
|
|
* 1 - Keyboard
|
|
* 2 - Mouse
|
|
*/
|
|
|
|
#define ENTROPYBIN 256 /* buckets to harvest entropy events */
|
|
#define TIMEBIN 16 /* max value for Pt/t */
|
|
|
|
#define HARVESTSIZE 16 /* max size of each harvested entropy unit */
|
|
|
|
#define FAST 0
|
|
#define SLOW 1
|
|
|
|
int random_init(void);
|
|
void random_deinit(void);
|
|
void random_init_harvester(void (*)(struct timespec *, void *, u_int, u_int, u_int, enum esource), u_int (*)(void *, u_int));
|
|
void random_deinit_harvester(void);
|
|
void random_set_wakeup_exit(void *);
|
|
|
|
u_int read_random_real(void *, u_int);
|
|
void write_random(void *, u_int);
|
|
|
|
/* This is the beastie that needs protecting. It contains all of the
|
|
* state that we are excited about.
|
|
* This is a biiig structure. It may move over to a malloc(9)ed
|
|
* replacement.
|
|
*/
|
|
struct random_state {
|
|
u_int64_t counter; /* C */
|
|
struct yarrowkey key; /* K */
|
|
int gengateinterval; /* Pg */
|
|
int bins; /* Pt/t */
|
|
int outputblocks; /* count output blocks for gates */
|
|
u_int slowoverthresh; /* slow pool overthreshhold reseed count */
|
|
struct pool {
|
|
struct source {
|
|
u_int bits; /* estimated bits of entropy */
|
|
u_int frac; /* fractional bits of entropy
|
|
(given as 1024/n) */
|
|
} source[ENTROPYSOURCE];
|
|
u_int thresh; /* pool reseed threshhold */
|
|
struct yarrowhash hash; /* accumulated entropy */
|
|
} pool[2]; /* pool[0] is fast, pool[1] is slow */
|
|
int which; /* toggle - shows the current insertion pool */
|
|
int seeded; /* 0 until first reseed, then 1 */
|
|
struct selinfo rsel; /* For poll(2) */
|
|
};
|
|
|
|
extern struct random_state random_state;
|