RetroZilla/security/nss/lib/freebl/mpi/utils/primegen.c

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2015-10-21 05:03:22 +02:00
/*
* primegen.c
*
* Generates random integers which are prime with a high degree of
* probability using the Miller-Rabin probabilistic primality testing
* algorithm.
*
* Usage:
* primegen <bits> [<num>]
*
* <bits> - number of significant bits each prime should have
* <num> - number of primes to generate
*
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* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
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#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <limits.h>
#include <time.h>
#include "mpi.h"
#include "mplogic.h"
#include "mpprime.h"
#define NUM_TESTS 5 /* Number of Rabin-Miller iterations to test with */
#ifdef DEBUG
#define FPUTC(x,y) fputc(x,y)
#else
#define FPUTC(x,y)
#endif
int main(int argc, char *argv[])
{
unsigned char *raw;
char *out;
unsigned long nTries;
int rawlen, bits, outlen, ngen, ix, jx;
int g_strong = 0;
mp_int testval;
mp_err res;
clock_t start, end;
/* We'll just use the C library's rand() for now, although this
won't be good enough for cryptographic purposes */
if((out = getenv("SEED")) == NULL) {
srand((unsigned int)time(NULL));
} else {
srand((unsigned int)atoi(out));
}
if(argc < 2) {
fprintf(stderr, "Usage: %s <bits> [<count> [strong]]\n", argv[0]);
return 1;
}
if((bits = abs(atoi(argv[1]))) < CHAR_BIT) {
fprintf(stderr, "%s: please request at least %d bits.\n",
argv[0], CHAR_BIT);
return 1;
}
/* If optional third argument is given, use that as the number of
primes to generate; otherwise generate one prime only.
*/
if(argc < 3) {
ngen = 1;
} else {
ngen = abs(atoi(argv[2]));
}
/* If fourth argument is given, and is the word "strong", we'll
generate strong (Sophie Germain) primes.
*/
if(argc > 3 && strcmp(argv[3], "strong") == 0)
g_strong = 1;
/* testval - candidate being tested; nTries - number tried so far */
if ((res = mp_init(&testval)) != MP_OKAY) {
fprintf(stderr, "%s: error: %s\n", argv[0], mp_strerror(res));
return 1;
}
if(g_strong) {
printf("Requested %d strong prime value(s) of %d bits.\n",
ngen, bits);
} else {
printf("Requested %d prime value(s) of %d bits.\n", ngen, bits);
}
rawlen = (bits / CHAR_BIT) + ((bits % CHAR_BIT) ? 1 : 0) + 1;
if((raw = calloc(rawlen, sizeof(unsigned char))) == NULL) {
fprintf(stderr, "%s: out of memory, sorry.\n", argv[0]);
return 1;
}
/* This loop is one for each prime we need to generate */
for(jx = 0; jx < ngen; jx++) {
raw[0] = 0; /* sign is positive */
/* Pack the initializer with random bytes */
for(ix = 1; ix < rawlen; ix++)
raw[ix] = (rand() * rand()) & UCHAR_MAX;
raw[1] |= 0x80; /* set high-order bit of test value */
raw[rawlen - 1] |= 1; /* set low-order bit of test value */
/* Make an mp_int out of the initializer */
mp_read_raw(&testval, (char *)raw, rawlen);
/* Initialize candidate counter */
nTries = 0;
start = clock(); /* time generation for this prime */
do {
res = mpp_make_prime(&testval, bits, g_strong, &nTries);
if (res != MP_NO)
break;
/* This code works whether digits are 16 or 32 bits */
res = mp_add_d(&testval, 32 * 1024, &testval);
res = mp_add_d(&testval, 32 * 1024, &testval);
FPUTC(',', stderr);
} while (1);
end = clock();
if (res != MP_YES) {
break;
}
FPUTC('\n', stderr);
puts("The following value is probably prime:");
outlen = mp_radix_size(&testval, 10);
out = calloc(outlen, sizeof(unsigned char));
mp_toradix(&testval, (char *)out, 10);
printf("10: %s\n", out);
mp_toradix(&testval, (char *)out, 16);
printf("16: %s\n\n", out);
free(out);
printf("Number of candidates tried: %lu\n", nTries);
printf("This computation took %ld clock ticks (%.2f seconds)\n",
(end - start), ((double)(end - start) / CLOCKS_PER_SEC));
FPUTC('\n', stderr);
} /* end of loop to generate all requested primes */
if(res != MP_OKAY)
fprintf(stderr, "%s: error: %s\n", argv[0], mp_strerror(res));
free(raw);
mp_clear(&testval);
return 0;
}