The Tor Browser: security/nss/lib/freebl/mpi/utils/bbs

Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.

     1 /*

     2  *  Blum, Blum & Shub PRNG using the MPI library

     3  *

     4  * This Source Code Form is subject to the terms of the Mozilla Public

     5  * License, v. 2.0. If a copy of the MPL was not distributed with this

     6  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

     8 #include "bbs_rand.h"

    10 #define SEED     1

    11 #define MODULUS  2

    13 /* This modulus is the product of two randomly generated 512-bit

    14    prime integers, each of which is congruent to 3 (mod 4).          */

    15 static char *bbs_modulus =

    16 "75A2A6E1D27393B86562B9CE7279A8403CB4258A637DAB5233465373E37837383EDC"

    17 "332282B8575927BC4172CE8C147B4894050EE9D2BDEED355C121037270CA2570D127"

    18 "7D2390CD1002263326635CC6B259148DE3A1A03201980A925E395E646A5E9164B0EC"

    19 "28559EBA58C87447245ADD0651EDA507056A1129E3A3E16E903D64B437";

    21 static int    bbs_init = 0;  /* flag set when library is initialized */

    22 static mp_int bbs_state;     /* the current state of the generator   */

    24 /* Suggested size of random seed data */

    25 int           bbs_seed_size = (sizeof(bbs_modulus) / 2);

    27 void         bbs_srand(unsigned char *data, int len)

    28 {

    29   if((bbs_init & SEED) == 0) {

    30     mp_init(&bbs_state);

    31     bbs_init |= SEED;

    32   }

    34   mp_read_raw(&bbs_state, (char *)data, len);

    36 } /* end bbs_srand() */

    38 unsigned int bbs_rand(void)

    39 {

    40   static mp_int   modulus;

    41   unsigned int    result = 0, ix;

    43   if((bbs_init & MODULUS) == 0) {

    44     mp_init(&modulus);

    45     mp_read_radix(&modulus, bbs_modulus, 16);

    46     bbs_init |= MODULUS;

    47   }

    49   for(ix = 0; ix < sizeof(unsigned int); ix++) {

    50     mp_digit   d;

    52     mp_sqrmod(&bbs_state, &modulus, &bbs_state);

    53     d = DIGIT(&bbs_state, 0);

    55     result = (result << CHAR_BIT) | (d & UCHAR_MAX);

    56   }

    58   return result;

    60 } /* end bbs_rand() */

    62 /*------------------------------------------------------------------------*/

    63 /* HERE THERE BE DRAGONS                                                  */

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