| Index: mozilla/security/nss/lib/freebl/mpi/mpprime.c
|
| ===================================================================
|
| --- mozilla/security/nss/lib/freebl/mpi/mpprime.c (revision 191424)
|
| +++ mozilla/security/nss/lib/freebl/mpi/mpprime.c (working copy)
|
| @@ -1,584 +0,0 @@
|
| -/*
|
| - * mpprime.c
|
| - *
|
| - * Utilities for finding and working with prime and pseudo-prime
|
| - * integers
|
| - *
|
| - * 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/. */
|
| -
|
| -#include "mpi-priv.h"
|
| -#include "mpprime.h"
|
| -#include "mplogic.h"
|
| -#include <stdlib.h>
|
| -#include <string.h>
|
| -
|
| -#define SMALL_TABLE 0 /* determines size of hard-wired prime table */
|
| -
|
| -#define RANDOM() rand()
|
| -
|
| -#include "primes.c" /* pull in the prime digit table */
|
| -
|
| -/*
|
| - Test if any of a given vector of digits divides a. If not, MP_NO
|
| - is returned; otherwise, MP_YES is returned and 'which' is set to
|
| - the index of the integer in the vector which divided a.
|
| - */
|
| -mp_err s_mpp_divp(mp_int *a, const mp_digit *vec, int size, int *which);
|
| -
|
| -/* {{{ mpp_divis(a, b) */
|
| -
|
| -/*
|
| - mpp_divis(a, b)
|
| -
|
| - Returns MP_YES if a is divisible by b, or MP_NO if it is not.
|
| - */
|
| -
|
| -mp_err mpp_divis(mp_int *a, mp_int *b)
|
| -{
|
| - mp_err res;
|
| - mp_int rem;
|
| -
|
| - if((res = mp_init(&rem)) != MP_OKAY)
|
| - return res;
|
| -
|
| - if((res = mp_mod(a, b, &rem)) != MP_OKAY)
|
| - goto CLEANUP;
|
| -
|
| - if(mp_cmp_z(&rem) == 0)
|
| - res = MP_YES;
|
| - else
|
| - res = MP_NO;
|
| -
|
| -CLEANUP:
|
| - mp_clear(&rem);
|
| - return res;
|
| -
|
| -} /* end mpp_divis() */
|
| -
|
| -/* }}} */
|
| -
|
| -/* {{{ mpp_divis_d(a, d) */
|
| -
|
| -/*
|
| - mpp_divis_d(a, d)
|
| -
|
| - Return MP_YES if a is divisible by d, or MP_NO if it is not.
|
| - */
|
| -
|
| -mp_err mpp_divis_d(mp_int *a, mp_digit d)
|
| -{
|
| - mp_err res;
|
| - mp_digit rem;
|
| -
|
| - ARGCHK(a != NULL, MP_BADARG);
|
| -
|
| - if(d == 0)
|
| - return MP_NO;
|
| -
|
| - if((res = mp_mod_d(a, d, &rem)) != MP_OKAY)
|
| - return res;
|
| -
|
| - if(rem == 0)
|
| - return MP_YES;
|
| - else
|
| - return MP_NO;
|
| -
|
| -} /* end mpp_divis_d() */
|
| -
|
| -/* }}} */
|
| -
|
| -/* {{{ mpp_random(a) */
|
| -
|
| -/*
|
| - mpp_random(a)
|
| -
|
| - Assigns a random value to a. This value is generated using the
|
| - standard C library's rand() function, so it should not be used for
|
| - cryptographic purposes, but it should be fine for primality testing,
|
| - since all we really care about there is good statistical properties.
|
| -
|
| - As many digits as a currently has are filled with random digits.
|
| - */
|
| -
|
| -mp_err mpp_random(mp_int *a)
|
| -
|
| -{
|
| - mp_digit next = 0;
|
| - unsigned int ix, jx;
|
| -
|
| - ARGCHK(a != NULL, MP_BADARG);
|
| -
|
| - for(ix = 0; ix < USED(a); ix++) {
|
| - for(jx = 0; jx < sizeof(mp_digit); jx++) {
|
| - next = (next << CHAR_BIT) | (RANDOM() & UCHAR_MAX);
|
| - }
|
| - DIGIT(a, ix) = next;
|
| - }
|
| -
|
| - return MP_OKAY;
|
| -
|
| -} /* end mpp_random() */
|
| -
|
| -/* }}} */
|
| -
|
| -/* {{{ mpp_random_size(a, prec) */
|
| -
|
| -mp_err mpp_random_size(mp_int *a, mp_size prec)
|
| -{
|
| - mp_err res;
|
| -
|
| - ARGCHK(a != NULL && prec > 0, MP_BADARG);
|
| -
|
| - if((res = s_mp_pad(a, prec)) != MP_OKAY)
|
| - return res;
|
| -
|
| - return mpp_random(a);
|
| -
|
| -} /* end mpp_random_size() */
|
| -
|
| -/* }}} */
|
| -
|
| -/* {{{ mpp_divis_vector(a, vec, size, which) */
|
| -
|
| -/*
|
| - mpp_divis_vector(a, vec, size, which)
|
| -
|
| - Determines if a is divisible by any of the 'size' digits in vec.
|
| - Returns MP_YES and sets 'which' to the index of the offending digit,
|
| - if it is; returns MP_NO if it is not.
|
| - */
|
| -
|
| -mp_err mpp_divis_vector(mp_int *a, const mp_digit *vec, int size, int *which)
|
| -{
|
| - ARGCHK(a != NULL && vec != NULL && size > 0, MP_BADARG);
|
| -
|
| - return s_mpp_divp(a, vec, size, which);
|
| -
|
| -} /* end mpp_divis_vector() */
|
| -
|
| -/* }}} */
|
| -
|
| -/* {{{ mpp_divis_primes(a, np) */
|
| -
|
| -/*
|
| - mpp_divis_primes(a, np)
|
| -
|
| - Test whether a is divisible by any of the first 'np' primes. If it
|
| - is, returns MP_YES and sets *np to the value of the digit that did
|
| - it. If not, returns MP_NO.
|
| - */
|
| -mp_err mpp_divis_primes(mp_int *a, mp_digit *np)
|
| -{
|
| - int size, which;
|
| - mp_err res;
|
| -
|
| - ARGCHK(a != NULL && np != NULL, MP_BADARG);
|
| -
|
| - size = (int)*np;
|
| - if(size > prime_tab_size)
|
| - size = prime_tab_size;
|
| -
|
| - res = mpp_divis_vector(a, prime_tab, size, &which);
|
| - if(res == MP_YES)
|
| - *np = prime_tab[which];
|
| -
|
| - return res;
|
| -
|
| -} /* end mpp_divis_primes() */
|
| -
|
| -/* }}} */
|
| -
|
| -/* {{{ mpp_fermat(a, w) */
|
| -
|
| -/*
|
| - Using w as a witness, try pseudo-primality testing based on Fermat's
|
| - little theorem. If a is prime, and (w, a) = 1, then w^a == w (mod
|
| - a). So, we compute z = w^a (mod a) and compare z to w; if they are
|
| - equal, the test passes and we return MP_YES. Otherwise, we return
|
| - MP_NO.
|
| - */
|
| -mp_err mpp_fermat(mp_int *a, mp_digit w)
|
| -{
|
| - mp_int base, test;
|
| - mp_err res;
|
| -
|
| - if((res = mp_init(&base)) != MP_OKAY)
|
| - return res;
|
| -
|
| - mp_set(&base, w);
|
| -
|
| - if((res = mp_init(&test)) != MP_OKAY)
|
| - goto TEST;
|
| -
|
| - /* Compute test = base^a (mod a) */
|
| - if((res = mp_exptmod(&base, a, a, &test)) != MP_OKAY)
|
| - goto CLEANUP;
|
| -
|
| -
|
| - if(mp_cmp(&base, &test) == 0)
|
| - res = MP_YES;
|
| - else
|
| - res = MP_NO;
|
| -
|
| - CLEANUP:
|
| - mp_clear(&test);
|
| - TEST:
|
| - mp_clear(&base);
|
| -
|
| - return res;
|
| -
|
| -} /* end mpp_fermat() */
|
| -
|
| -/* }}} */
|
| -
|
| -/*
|
| - Perform the fermat test on each of the primes in a list until
|
| - a) one of them shows a is not prime, or
|
| - b) the list is exhausted.
|
| - Returns: MP_YES if it passes tests.
|
| - MP_NO if fermat test reveals it is composite
|
| - Some MP error code if some other error occurs.
|
| - */
|
| -mp_err mpp_fermat_list(mp_int *a, const mp_digit *primes, mp_size nPrimes)
|
| -{
|
| - mp_err rv = MP_YES;
|
| -
|
| - while (nPrimes-- > 0 && rv == MP_YES) {
|
| - rv = mpp_fermat(a, *primes++);
|
| - }
|
| - return rv;
|
| -}
|
| -
|
| -/* {{{ mpp_pprime(a, nt) */
|
| -
|
| -/*
|
| - mpp_pprime(a, nt)
|
| -
|
| - Performs nt iteration of the Miller-Rabin probabilistic primality
|
| - test on a. Returns MP_YES if the tests pass, MP_NO if one fails.
|
| - If MP_NO is returned, the number is definitely composite. If MP_YES
|
| - is returned, it is probably prime (but that is not guaranteed).
|
| - */
|
| -
|
| -mp_err mpp_pprime(mp_int *a, int nt)
|
| -{
|
| - mp_err res;
|
| - mp_int x, amo, m, z; /* "amo" = "a minus one" */
|
| - int iter;
|
| - unsigned int jx;
|
| - mp_size b;
|
| -
|
| - ARGCHK(a != NULL, MP_BADARG);
|
| -
|
| - MP_DIGITS(&x) = 0;
|
| - MP_DIGITS(&amo) = 0;
|
| - MP_DIGITS(&m) = 0;
|
| - MP_DIGITS(&z) = 0;
|
| -
|
| - /* Initialize temporaries... */
|
| - MP_CHECKOK( mp_init(&amo));
|
| - /* Compute amo = a - 1 for what follows... */
|
| - MP_CHECKOK( mp_sub_d(a, 1, &amo) );
|
| -
|
| - b = mp_trailing_zeros(&amo);
|
| - if (!b) { /* a was even ? */
|
| - res = MP_NO;
|
| - goto CLEANUP;
|
| - }
|
| -
|
| - MP_CHECKOK( mp_init_size(&x, MP_USED(a)) );
|
| - MP_CHECKOK( mp_init(&z) );
|
| - MP_CHECKOK( mp_init(&m) );
|
| - MP_CHECKOK( mp_div_2d(&amo, b, &m, 0) );
|
| -
|
| - /* Do the test nt times... */
|
| - for(iter = 0; iter < nt; iter++) {
|
| -
|
| - /* Choose a random value for 1 < x < a */
|
| - s_mp_pad(&x, USED(a));
|
| - mpp_random(&x);
|
| - MP_CHECKOK( mp_mod(&x, a, &x) );
|
| - if(mp_cmp_d(&x, 1) <= 0) {
|
| - iter--; /* don't count this iteration */
|
| - continue; /* choose a new x */
|
| - }
|
| -
|
| - /* Compute z = (x ** m) mod a */
|
| - MP_CHECKOK( mp_exptmod(&x, &m, a, &z) );
|
| -
|
| - if(mp_cmp_d(&z, 1) == 0 || mp_cmp(&z, &amo) == 0) {
|
| - res = MP_YES;
|
| - continue;
|
| - }
|
| -
|
| - res = MP_NO; /* just in case the following for loop never executes. */
|
| - for (jx = 1; jx < b; jx++) {
|
| - /* z = z^2 (mod a) */
|
| - MP_CHECKOK( mp_sqrmod(&z, a, &z) );
|
| - res = MP_NO; /* previous line set res to MP_YES */
|
| -
|
| - if(mp_cmp_d(&z, 1) == 0) {
|
| - break;
|
| - }
|
| - if(mp_cmp(&z, &amo) == 0) {
|
| - res = MP_YES;
|
| - break;
|
| - }
|
| - } /* end testing loop */
|
| -
|
| - /* If the test passes, we will continue iterating, but a failed
|
| - test means the candidate is definitely NOT prime, so we will
|
| - immediately break out of this loop
|
| - */
|
| - if(res == MP_NO)
|
| - break;
|
| -
|
| - } /* end iterations loop */
|
| -
|
| -CLEANUP:
|
| - mp_clear(&m);
|
| - mp_clear(&z);
|
| - mp_clear(&x);
|
| - mp_clear(&amo);
|
| - return res;
|
| -
|
| -} /* end mpp_pprime() */
|
| -
|
| -/* }}} */
|
| -
|
| -/* Produce table of composites from list of primes and trial value.
|
| -** trial must be odd. List of primes must not include 2.
|
| -** sieve should have dimension >= MAXPRIME/2, where MAXPRIME is largest
|
| -** prime in list of primes. After this function is finished,
|
| -** if sieve[i] is non-zero, then (trial + 2*i) is composite.
|
| -** Each prime used in the sieve costs one division of trial, and eliminates
|
| -** one or more values from the search space. (3 eliminates 1/3 of the values
|
| -** alone!) Each value left in the search space costs 1 or more modular
|
| -** exponentations. So, these divisions are a bargain!
|
| -*/
|
| -mp_err mpp_sieve(mp_int *trial, const mp_digit *primes, mp_size nPrimes,
|
| - unsigned char *sieve, mp_size nSieve)
|
| -{
|
| - mp_err res;
|
| - mp_digit rem;
|
| - mp_size ix;
|
| - unsigned long offset;
|
| -
|
| - memset(sieve, 0, nSieve);
|
| -
|
| - for(ix = 0; ix < nPrimes; ix++) {
|
| - mp_digit prime = primes[ix];
|
| - mp_size i;
|
| - if((res = mp_mod_d(trial, prime, &rem)) != MP_OKAY)
|
| - return res;
|
| -
|
| - if (rem == 0) {
|
| - offset = 0;
|
| - } else {
|
| - offset = prime - (rem / 2);
|
| - }
|
| - for (i = offset; i < nSieve ; i += prime) {
|
| - sieve[i] = 1;
|
| - }
|
| - }
|
| -
|
| - return MP_OKAY;
|
| -}
|
| -
|
| -#define SIEVE_SIZE 32*1024
|
| -
|
| -mp_err mpp_make_prime(mp_int *start, mp_size nBits, mp_size strong,
|
| - unsigned long * nTries)
|
| -{
|
| - mp_digit np;
|
| - mp_err res;
|
| - int i = 0;
|
| - mp_int trial;
|
| - mp_int q;
|
| - mp_size num_tests;
|
| - unsigned char *sieve;
|
| -
|
| - ARGCHK(start != 0, MP_BADARG);
|
| - ARGCHK(nBits > 16, MP_RANGE);
|
| -
|
| - sieve = malloc(SIEVE_SIZE);
|
| - ARGCHK(sieve != NULL, MP_MEM);
|
| -
|
| - MP_DIGITS(&trial) = 0;
|
| - MP_DIGITS(&q) = 0;
|
| - MP_CHECKOK( mp_init(&trial) );
|
| - MP_CHECKOK( mp_init(&q) );
|
| - /* values taken from table 4.4, HandBook of Applied Cryptography */
|
| - if (nBits >= 1300) {
|
| - num_tests = 2;
|
| - } else if (nBits >= 850) {
|
| - num_tests = 3;
|
| - } else if (nBits >= 650) {
|
| - num_tests = 4;
|
| - } else if (nBits >= 550) {
|
| - num_tests = 5;
|
| - } else if (nBits >= 450) {
|
| - num_tests = 6;
|
| - } else if (nBits >= 400) {
|
| - num_tests = 7;
|
| - } else if (nBits >= 350) {
|
| - num_tests = 8;
|
| - } else if (nBits >= 300) {
|
| - num_tests = 9;
|
| - } else if (nBits >= 250) {
|
| - num_tests = 12;
|
| - } else if (nBits >= 200) {
|
| - num_tests = 15;
|
| - } else if (nBits >= 150) {
|
| - num_tests = 18;
|
| - } else if (nBits >= 100) {
|
| - num_tests = 27;
|
| - } else
|
| - num_tests = 50;
|
| -
|
| - if (strong)
|
| - --nBits;
|
| - MP_CHECKOK( mpl_set_bit(start, nBits - 1, 1) );
|
| - MP_CHECKOK( mpl_set_bit(start, 0, 1) );
|
| - for (i = mpl_significant_bits(start) - 1; i >= nBits; --i) {
|
| - MP_CHECKOK( mpl_set_bit(start, i, 0) );
|
| - }
|
| - /* start sieveing with prime value of 3. */
|
| - MP_CHECKOK(mpp_sieve(start, prime_tab + 1, prime_tab_size - 1,
|
| - sieve, SIEVE_SIZE) );
|
| -
|
| -#ifdef DEBUG_SIEVE
|
| - res = 0;
|
| - for (i = 0; i < SIEVE_SIZE; ++i) {
|
| - if (!sieve[i])
|
| - ++res;
|
| - }
|
| - fprintf(stderr,"sieve found %d potential primes.\n", res);
|
| -#define FPUTC(x,y) fputc(x,y)
|
| -#else
|
| -#define FPUTC(x,y)
|
| -#endif
|
| -
|
| - res = MP_NO;
|
| - for(i = 0; i < SIEVE_SIZE; ++i) {
|
| - if (sieve[i]) /* this number is composite */
|
| - continue;
|
| - MP_CHECKOK( mp_add_d(start, 2 * i, &trial) );
|
| - FPUTC('.', stderr);
|
| - /* run a Fermat test */
|
| - res = mpp_fermat(&trial, 2);
|
| - if (res != MP_OKAY) {
|
| - if (res == MP_NO)
|
| - continue; /* was composite */
|
| - goto CLEANUP;
|
| - }
|
| -
|
| - FPUTC('+', stderr);
|
| - /* If that passed, run some Miller-Rabin tests */
|
| - res = mpp_pprime(&trial, num_tests);
|
| - if (res != MP_OKAY) {
|
| - if (res == MP_NO)
|
| - continue; /* was composite */
|
| - goto CLEANUP;
|
| - }
|
| - FPUTC('!', stderr);
|
| -
|
| - if (!strong)
|
| - break; /* success !! */
|
| -
|
| - /* At this point, we have strong evidence that our candidate
|
| - is itself prime. If we want a strong prime, we need now
|
| - to test q = 2p + 1 for primality...
|
| - */
|
| - MP_CHECKOK( mp_mul_2(&trial, &q) );
|
| - MP_CHECKOK( mp_add_d(&q, 1, &q) );
|
| -
|
| - /* Test q for small prime divisors ... */
|
| - np = prime_tab_size;
|
| - res = mpp_divis_primes(&q, &np);
|
| - if (res == MP_YES) { /* is composite */
|
| - mp_clear(&q);
|
| - continue;
|
| - }
|
| - if (res != MP_NO)
|
| - goto CLEANUP;
|
| -
|
| - /* And test with Fermat, as with its parent ... */
|
| - res = mpp_fermat(&q, 2);
|
| - if (res != MP_YES) {
|
| - mp_clear(&q);
|
| - if (res == MP_NO)
|
| - continue; /* was composite */
|
| - goto CLEANUP;
|
| - }
|
| -
|
| - /* And test with Miller-Rabin, as with its parent ... */
|
| - res = mpp_pprime(&q, num_tests);
|
| - if (res != MP_YES) {
|
| - mp_clear(&q);
|
| - if (res == MP_NO)
|
| - continue; /* was composite */
|
| - goto CLEANUP;
|
| - }
|
| -
|
| - /* If it passed, we've got a winner */
|
| - mp_exch(&q, &trial);
|
| - mp_clear(&q);
|
| - break;
|
| -
|
| - } /* end of loop through sieved values */
|
| - if (res == MP_YES)
|
| - mp_exch(&trial, start);
|
| -CLEANUP:
|
| - mp_clear(&trial);
|
| - mp_clear(&q);
|
| - if (nTries)
|
| - *nTries += i;
|
| - if (sieve != NULL) {
|
| - memset(sieve, 0, SIEVE_SIZE);
|
| - free (sieve);
|
| - }
|
| - return res;
|
| -}
|
| -
|
| -/*========================================================================*/
|
| -/*------------------------------------------------------------------------*/
|
| -/* Static functions visible only to the library internally */
|
| -
|
| -/* {{{ s_mpp_divp(a, vec, size, which) */
|
| -
|
| -/*
|
| - Test for divisibility by members of a vector of digits. Returns
|
| - MP_NO if a is not divisible by any of them; returns MP_YES and sets
|
| - 'which' to the index of the offender, if it is. Will stop on the
|
| - first digit against which a is divisible.
|
| - */
|
| -
|
| -mp_err s_mpp_divp(mp_int *a, const mp_digit *vec, int size, int *which)
|
| -{
|
| - mp_err res;
|
| - mp_digit rem;
|
| -
|
| - int ix;
|
| -
|
| - for(ix = 0; ix < size; ix++) {
|
| - if((res = mp_mod_d(a, vec[ix], &rem)) != MP_OKAY)
|
| - return res;
|
| -
|
| - if(rem == 0) {
|
| - if(which)
|
| - *which = ix;
|
| - return MP_YES;
|
| - }
|
| - }
|
| -
|
| - return MP_NO;
|
| -
|
| -} /* end s_mpp_divp() */
|
| -
|
| -/* }}} */
|
| -
|
| -/*------------------------------------------------------------------------*/
|
| -/* HERE THERE BE DRAGONS */
|
|
|