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 */ |