Back to index

lightning-sunbird  0.9+nobinonly
Defines | Functions | Variables
isprime.c File Reference
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "mpi.h"
#include "mpprime.h"

Go to the source code of this file.

Defines

#define RM_TESTS   15 /* how many iterations of Rabin-Miller? */
#define MINIMUM   1024 /* don't bother us with a < this */

Functions

int main (int argc, char *argv[])

Variables

int g_tests = RM_TESTS
char * g_prog = NULL

Define Documentation

#define MINIMUM   1024 /* don't bother us with a < this */

Definition at line 51 of file isprime.c.

#define RM_TESTS   15 /* how many iterations of Rabin-Miller? */

Definition at line 50 of file isprime.c.


Function Documentation

int main ( int  argc,
char *  argv[] 
)

Definition at line 56 of file isprime.c.

{
  mp_int   a;
  mp_digit np = prime_tab_size; /* from mpprime.h */
  int      res = 0;

  g_prog = argv[0];

  if(argc < 2) {
    fprintf(stderr, "Usage: %s <a>, where <a> is a decimal integer\n"
           "Use '0x' prefix for a hexadecimal value\n", g_prog);
    return 1;
  }

  /* Read number of tests from environment, if present */
  {
    char *tmp;

    if((tmp = getenv("RM_TESTS")) != NULL) {
      if((g_tests = atoi(tmp)) <= 0)
       g_tests = RM_TESTS;
    }
  }

  mp_init(&a);
  if(argv[1][0] == '0' && argv[1][1] == 'x')
    mp_read_radix(&a, argv[1] + 2, 16);
  else
    mp_read_radix(&a, argv[1], 10);

  if(mp_cmp_d(&a, MINIMUM) <= 0) {
    fprintf(stderr, "%s: please use a value greater than %d\n", 
           g_prog, MINIMUM);
    mp_clear(&a);
    return 1;
  }

  /* Test for divisibility by small primes */
  if(mpp_divis_primes(&a, &np) != MP_NO) {
    printf("Not prime (divisible by small prime %d)\n", np);
    res = 2;
    goto CLEANUP;
  }

  /* Test with Fermat's test, using 2 as a witness */
  if(mpp_fermat(&a, 2) != MP_YES) {
    printf("Not prime (failed Fermat test)\n");
    res = 2;
    goto CLEANUP;
  }
 
  /* Test with Rabin-Miller probabilistic test */
  if(mpp_pprime(&a, g_tests) == MP_NO) {
      printf("Not prime (failed pseudoprime test)\n");
      res = 2;
      goto CLEANUP;
  }

  printf("Probably prime, 1 in 4^%d chance of false positive\n", g_tests);

CLEANUP:
  mp_clear(&a);
  
  return res;

}

Here is the call graph for this function:


Variable Documentation

char* g_prog = NULL

Definition at line 54 of file isprime.c.

Definition at line 53 of file isprime.c.