freebsd-skq/sys/dev/random/yarrow.h
markm 55fe453be7 Reorganise the entropy device so that high-yield entropy sources
can more easily be used INSTEAD OF the hard-working Yarrow.
The only hardware source used at this point is the one inside
the VIA C3 Nehemiah (Stepping 3 and above) CPU. More sources will
be added in due course. Contributions welcome!
2004-04-09 15:47:10 +00:00

60 lines
2.3 KiB
C

/*-
* Copyright (c) 2000-2004 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.
*
* $FreeBSD$
*/
/* This contains Yarrow-specific declarations.
* See http://www.counterpane.com/yarrow.html
*/
#define TIMEBIN 16 /* max value for Pt/t */
#define FAST 0
#define SLOW 1
/* This is the beastie that needs protecting. It contains all of the
* state that we are excited about.
* Exactly one will be instantiated.
*/
struct random_state {
u_int64_t counter[4]; /* C - 256 bits */
struct yarrowkey key; /* K */
u_int gengateinterval; /* Pg */
u_int bins; /* Pt/t */
u_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 */
u_int which; /* toggle - sets the current insertion pool */
};