primegen.c
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上传日期:2007-01-12
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文件大小:6k
- /*
- * 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
- *
- * 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: primegen.c,v 1.4 2000/07/26 05:41:59 nelsonb%netscape.com Exp $
- */
- #include <stdio.h>
- #include <stdlib.h>
- #include <string.h>
- #include <limits.h>
- #include <time.h>
- #include "mpi.h"
- #include "mplogic.h"
- #include "mpprime.h"
- #undef MACOS /* define if running on a Macintosh */
- #ifdef MACOS
- #include <console.h>
- #endif
- #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;
- #ifdef MACOS
- argc = ccommand(&argv);
- #endif
- /* 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: %sn", 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);
- printf("After %d tests, the following value is still probably prime:n",
- NUM_TESTS);
- outlen = mp_radix_size(&testval, 10);
- out = calloc(outlen, sizeof(unsigned char));
- mp_toradix(&testval, (char *)out, 10);
- printf("10: %sn", out);
- mp_toradix(&testval, (char *)out, 16);
- printf("16: %snn", out);
- free(out);
-
- printf("Number of candidates tried: %lun", 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: %sn", argv[0], mp_strerror(res));
- free(raw);
- mp_clear(&testval);
-
- return 0;
- }