nelsonb%netscape.com 4a93e035ae MPI Arbitrary Precision Integer Arithmetic library.
The Initial Developer of the Original Code is
Michael J. Fromberger <sting@linguist.dartmouth.edu>


git-svn-id: svn://10.0.0.236/trunk@74223 18797224-902f-48f8-a5cc-f745e15eee43
2000-07-14 00:45:02 +00:00

94 lines
3.1 KiB
C

/*
* Blum, Blum & Shub PRNG using the MPI library
*
* The contents of this file are subject to the Mozilla Public
* License Version 1.1 (the "License"); you may not use this file
* except in compliance with the License. You may obtain a copy of
* the License at http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS
* IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
* implied. See the License for the specific language governing
* rights and limitations under the License.
*
* The Original Code is the MPI Arbitrary Precision Integer Arithmetic
* library.
*
* The Initial Developer of the Original Code is Michael J. Fromberger.
* Portions created by Michael J. Fromberger are
* Copyright (C) 1998, 1999, 2000 Michael J. Fromberger.
* All Rights Reserved.
*
* Contributor(s):
*
* Alternatively, the contents of this file may be used under the
* terms of the GNU General Public License Version 2 or later (the
* "GPL"), in which case the provisions of the GPL are applicable
* instead of those above. If you wish to allow use of your
* version of this file only under the terms of the GPL and not to
* allow others to use your version of this file under the MPL,
* indicate your decision by deleting the provisions above and
* replace them with the notice and other provisions required by
* the GPL. If you do not delete the provisions above, a recipient
* may use your version of this file under either the MPL or the GPL.
*
* $Id: bbs_rand.c,v 1.1 2000-07-14 00:44:53 nelsonb%netscape.com Exp $
*/
#include "bbs_rand.h"
#define SEED 1
#define MODULUS 2
/* This modulus is the product of two randomly generated 512-bit
prime integers, each of which is congruent to 3 (mod 4). */
static char *bbs_modulus =
"75A2A6E1D27393B86562B9CE7279A8403CB4258A637DAB5233465373E37837383EDC"
"332282B8575927BC4172CE8C147B4894050EE9D2BDEED355C121037270CA2570D127"
"7D2390CD1002263326635CC6B259148DE3A1A03201980A925E395E646A5E9164B0EC"
"28559EBA58C87447245ADD0651EDA507056A1129E3A3E16E903D64B437";
static int bbs_init = 0; /* flag set when library is initialized */
static mp_int bbs_state; /* the current state of the generator */
/* Suggested size of random seed data */
int bbs_seed_size = (sizeof(bbs_modulus) / 2);
void bbs_srand(unsigned char *data, int len)
{
if((bbs_init & SEED) == 0) {
mp_init(&bbs_state);
bbs_init |= SEED;
}
mp_read_raw(&bbs_state, (char *)data, len);
} /* end bbs_srand() */
unsigned int bbs_rand(void)
{
static mp_int modulus;
unsigned int result = 0, ix;
if((bbs_init & MODULUS) == 0) {
mp_init(&modulus);
mp_read_radix(&modulus, bbs_modulus, 16);
bbs_init |= MODULUS;
}
for(ix = 0; ix < sizeof(unsigned int); ix++) {
mp_digit d;
mp_sqrmod(&bbs_state, &modulus, &bbs_state);
d = DIGIT(&bbs_state, 0);
result = (result << CHAR_BIT) | (d & UCHAR_MAX);
}
return result;
} /* end bbs_rand() */
/*------------------------------------------------------------------------*/
/* HERE THERE BE DRAGONS */