diff options
Diffstat (limited to 'crypto/bn/bn_prime.c')
| -rw-r--r-- | crypto/bn/bn_prime.c | 331 |
1 files changed, 148 insertions, 183 deletions
diff --git a/crypto/bn/bn_prime.c b/crypto/bn/bn_prime.c index e911e157859a..b91b31b1f304 100644 --- a/crypto/bn/bn_prime.c +++ b/crypto/bn/bn_prime.c @@ -1,125 +1,16 @@ -/* crypto/bn/bn_prime.c */ -/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) - * All rights reserved. - * - * This package is an SSL implementation written - * by Eric Young (eay@cryptsoft.com). - * The implementation was written so as to conform with Netscapes SSL. - * - * This library is free for commercial and non-commercial use as long as - * the following conditions are aheared to. The following conditions - * apply to all code found in this distribution, be it the RC4, RSA, - * lhash, DES, etc., code; not just the SSL code. The SSL documentation - * included with this distribution is covered by the same copyright terms - * except that the holder is Tim Hudson (tjh@cryptsoft.com). - * - * Copyright remains Eric Young's, and as such any Copyright notices in - * the code are not to be removed. - * If this package is used in a product, Eric Young should be given attribution - * as the author of the parts of the library used. - * This can be in the form of a textual message at program startup or - * in documentation (online or textual) provided with the package. - * - * Redistribution and use in source and binary forms, with or without - * modification, are permitted provided that the following conditions - * are met: - * 1. Redistributions of source code must retain the copyright - * notice, this list of conditions and the following disclaimer. - * 2. Redistributions in binary form must reproduce the above copyright - * notice, this list of conditions and the following disclaimer in the - * documentation and/or other materials provided with the distribution. - * 3. All advertising materials mentioning features or use of this software - * must display the following acknowledgement: - * "This product includes cryptographic software written by - * Eric Young (eay@cryptsoft.com)" - * The word 'cryptographic' can be left out if the rouines from the library - * being used are not cryptographic related :-). - * 4. If you include any Windows specific code (or a derivative thereof) from - * the apps directory (application code) you must include an acknowledgement: - * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" - * - * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND - * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE - * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE - * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE - * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL - * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS - * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) - * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT - * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY - * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF - * SUCH DAMAGE. - * - * The licence and distribution terms for any publically available version or - * derivative of this code cannot be changed. i.e. this code cannot simply be - * copied and put under another distribution licence - * [including the GNU Public Licence.] - */ -/* ==================================================================== - * Copyright (c) 1998-2001 The OpenSSL Project. All rights reserved. - * - * Redistribution and use in source and binary forms, with or without - * modification, are permitted provided that the following conditions - * are met: - * - * 1. Redistributions of source code must retain the above copyright - * notice, this list of conditions and the following disclaimer. - * - * 2. Redistributions in binary form must reproduce the above copyright - * notice, this list of conditions and the following disclaimer in - * the documentation and/or other materials provided with the - * distribution. - * - * 3. All advertising materials mentioning features or use of this - * software must display the following acknowledgment: - * "This product includes software developed by the OpenSSL Project - * for use in the OpenSSL Toolkit. (http://www.openssl.org/)" - * - * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to - * endorse or promote products derived from this software without - * prior written permission. For written permission, please contact - * openssl-core@openssl.org. - * - * 5. Products derived from this software may not be called "OpenSSL" - * nor may "OpenSSL" appear in their names without prior written - * permission of the OpenSSL Project. - * - * 6. Redistributions of any form whatsoever must retain the following - * acknowledgment: - * "This product includes software developed by the OpenSSL Project - * for use in the OpenSSL Toolkit (http://www.openssl.org/)" - * - * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY - * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE - * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR - * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR - * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, - * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT - * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; - * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) - * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, - * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) - * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED - * OF THE POSSIBILITY OF SUCH DAMAGE. - * ==================================================================== - * - * This product includes cryptographic software written by Eric Young - * (eay@cryptsoft.com). This product includes software written by Tim - * Hudson (tjh@cryptsoft.com). +/* + * Copyright 1995-2018 The OpenSSL Project Authors. All Rights Reserved. * + * Licensed under the OpenSSL license (the "License"). You may not use + * this file except in compliance with the License. You can obtain a copy + * in the file LICENSE in the source distribution or at + * https://www.openssl.org/source/license.html */ #include <stdio.h> #include <time.h> -#include "cryptlib.h" +#include "internal/cryptlib.h" #include "bn_lcl.h" -#include <openssl/rand.h> - -/* - * NB: these functions have been "upgraded", the deprecated versions (which - * are compatibility wrappers using these functions) are in bn_depr.c. - - * Geoff - */ /* * The quick sieve algorithm approach to weeding out primes is Philip @@ -131,12 +22,10 @@ static int witness(BIGNUM *w, const BIGNUM *a, const BIGNUM *a1, const BIGNUM *a1_odd, int k, BN_CTX *ctx, BN_MONT_CTX *mont); -static int probable_prime(BIGNUM *rnd, int bits); -static int probable_prime_dh(BIGNUM *rnd, int bits, - const BIGNUM *add, const BIGNUM *rem, - BN_CTX *ctx); -static int probable_prime_dh_safe(BIGNUM *rnd, int bits, const BIGNUM *add, - const BIGNUM *rem, BN_CTX *ctx); +static int probable_prime(BIGNUM *rnd, int bits, prime_t *mods); +static int probable_prime_dh_safe(BIGNUM *rnd, int bits, + const BIGNUM *add, const BIGNUM *rem, + BN_CTX *ctx); int BN_GENCB_call(BN_GENCB *cb, int a, int b) { @@ -166,31 +55,46 @@ int BN_generate_prime_ex(BIGNUM *ret, int bits, int safe, BIGNUM *t; int found = 0; int i, j, c1 = 0; - BN_CTX *ctx; + BN_CTX *ctx = NULL; + prime_t *mods = NULL; int checks = BN_prime_checks_for_size(bits); + if (bits < 2) { + /* There are no prime numbers this small. */ + BNerr(BN_F_BN_GENERATE_PRIME_EX, BN_R_BITS_TOO_SMALL); + return 0; + } else if (bits == 2 && safe) { + /* The smallest safe prime (7) is three bits. */ + BNerr(BN_F_BN_GENERATE_PRIME_EX, BN_R_BITS_TOO_SMALL); + return 0; + } + + mods = OPENSSL_zalloc(sizeof(*mods) * NUMPRIMES); + if (mods == NULL) + goto err; + ctx = BN_CTX_new(); if (ctx == NULL) goto err; BN_CTX_start(ctx); t = BN_CTX_get(ctx); - if (!t) + if (t == NULL) goto err; loop: /* make a random number and set the top and bottom bits */ if (add == NULL) { - if (!probable_prime(ret, bits)) + if (!probable_prime(ret, bits, mods)) goto err; } else { if (safe) { if (!probable_prime_dh_safe(ret, bits, add, rem, ctx)) goto err; } else { - if (!probable_prime_dh(ret, bits, add, rem, ctx)) + if (!bn_probable_prime_dh(ret, bits, add, rem, ctx)) goto err; } } - /* if (BN_mod_word(ret,(BN_ULONG)3) == 1) goto loop; */ + if (!BN_GENCB_call(cb, 0, c1++)) /* aborted */ goto err; @@ -230,10 +134,10 @@ int BN_generate_prime_ex(BIGNUM *ret, int bits, int safe, /* we have a prime :-) */ found = 1; err: - if (ctx != NULL) { + OPENSSL_free(mods); + if (ctx != NULL) BN_CTX_end(ctx); - BN_CTX_free(ctx); - } + BN_CTX_free(ctx); bn_check_top(ret); return found; } @@ -250,23 +154,29 @@ int BN_is_prime_fasttest_ex(const BIGNUM *a, int checks, BN_CTX *ctx_passed, int i, j, ret = -1; int k; BN_CTX *ctx = NULL; - BIGNUM *A1, *A1_odd, *check; /* taken from ctx */ + BIGNUM *A1, *A1_odd, *A3, *check; /* taken from ctx */ BN_MONT_CTX *mont = NULL; - if (BN_cmp(a, BN_value_one()) <= 0) + /* Take care of the really small primes 2 & 3 */ + if (BN_is_word(a, 2) || BN_is_word(a, 3)) + return 1; + + /* Check odd and bigger than 1 */ + if (!BN_is_odd(a) || BN_cmp(a, BN_value_one()) <= 0) return 0; if (checks == BN_prime_checks) checks = BN_prime_checks_for_size(BN_num_bits(a)); /* first look for small factors */ - if (!BN_is_odd(a)) - /* a is even => a is prime if and only if a == 2 */ - return BN_is_word(a, 2); if (do_trial_division) { - for (i = 1; i < NUMPRIMES; i++) - if (BN_mod_word(a, primes[i]) == 0) - return 0; + for (i = 1; i < NUMPRIMES; i++) { + BN_ULONG mod = BN_mod_word(a, primes[i]); + if (mod == (BN_ULONG)-1) + goto err; + if (mod == 0) + return BN_is_word(a, primes[i]); + } if (!BN_GENCB_call(cb, 1, -1)) goto err; } @@ -278,20 +188,18 @@ int BN_is_prime_fasttest_ex(const BIGNUM *a, int checks, BN_CTX *ctx_passed, BN_CTX_start(ctx); A1 = BN_CTX_get(ctx); + A3 = BN_CTX_get(ctx); A1_odd = BN_CTX_get(ctx); check = BN_CTX_get(ctx); if (check == NULL) goto err; /* compute A1 := a - 1 */ - if (!BN_copy(A1, a)) + if (!BN_copy(A1, a) || !BN_sub_word(A1, 1)) goto err; - if (!BN_sub_word(A1, 1)) + /* compute A3 := a - 3 */ + if (!BN_copy(A3, a) || !BN_sub_word(A3, 3)) goto err; - if (BN_is_zero(A1)) { - ret = 0; - goto err; - } /* write A1 as A1_odd * 2^k */ k = 1; @@ -308,11 +216,9 @@ int BN_is_prime_fasttest_ex(const BIGNUM *a, int checks, BN_CTX *ctx_passed, goto err; for (i = 0; i < checks; i++) { - if (!BN_pseudo_rand_range(check, A1)) + /* 1 < check < a-1 */ + if (!BN_priv_rand_range(check, A3) || !BN_add_word(check, 2)) goto err; - if (!BN_add_word(check, 1)) - goto err; - /* now 1 <= check < a */ j = witness(check, a, A1, A1_odd, k, ctx, mont); if (j == -1) @@ -331,10 +237,9 @@ int BN_is_prime_fasttest_ex(const BIGNUM *a, int checks, BN_CTX *ctx_passed, if (ctx_passed == NULL) BN_CTX_free(ctx); } - if (mont != NULL) - BN_MONT_CTX_free(mont); + BN_MONT_CTX_free(mont); - return (ret); + return ret; } static int witness(BIGNUM *w, const BIGNUM *a, const BIGNUM *a1, @@ -364,41 +269,91 @@ static int witness(BIGNUM *w, const BIGNUM *a, const BIGNUM *a1, return 1; } -static int probable_prime(BIGNUM *rnd, int bits) +static int probable_prime(BIGNUM *rnd, int bits, prime_t *mods) { int i; - prime_t mods[NUMPRIMES]; - BN_ULONG delta, maxdelta; + BN_ULONG delta; + BN_ULONG maxdelta = BN_MASK2 - primes[NUMPRIMES - 1]; + char is_single_word = bits <= BN_BITS2; again: - if (!BN_rand(rnd, bits, 1, 1)) - return (0); - /* we now have a random number 'rand' to test. */ - for (i = 1; i < NUMPRIMES; i++) - mods[i] = (prime_t) BN_mod_word(rnd, (BN_ULONG)primes[i]); - maxdelta = BN_MASK2 - primes[NUMPRIMES - 1]; + /* TODO: Not all primes are private */ + if (!BN_priv_rand(rnd, bits, BN_RAND_TOP_TWO, BN_RAND_BOTTOM_ODD)) + return 0; + /* we now have a random number 'rnd' to test. */ + for (i = 1; i < NUMPRIMES; i++) { + BN_ULONG mod = BN_mod_word(rnd, (BN_ULONG)primes[i]); + if (mod == (BN_ULONG)-1) + return 0; + mods[i] = (prime_t) mod; + } + /* + * If bits is so small that it fits into a single word then we + * additionally don't want to exceed that many bits. + */ + if (is_single_word) { + BN_ULONG size_limit; + + if (bits == BN_BITS2) { + /* + * Shifting by this much has undefined behaviour so we do it a + * different way + */ + size_limit = ~((BN_ULONG)0) - BN_get_word(rnd); + } else { + size_limit = (((BN_ULONG)1) << bits) - BN_get_word(rnd) - 1; + } + if (size_limit < maxdelta) + maxdelta = size_limit; + } delta = 0; - loop:for (i = 1; i < NUMPRIMES; i++) { - /* - * check that rnd is not a prime and also that gcd(rnd-1,primes) == 1 - * (except for 2) + loop: + if (is_single_word) { + BN_ULONG rnd_word = BN_get_word(rnd); + + /*- + * In the case that the candidate prime is a single word then + * we check that: + * 1) It's greater than primes[i] because we shouldn't reject + * 3 as being a prime number because it's a multiple of + * three. + * 2) That it's not a multiple of a known prime. We don't + * check that rnd-1 is also coprime to all the known + * primes because there aren't many small primes where + * that's true. */ - if (((mods[i] + delta) % primes[i]) <= 1) { - delta += 2; - if (delta > maxdelta) - goto again; - goto loop; + for (i = 1; i < NUMPRIMES && primes[i] < rnd_word; i++) { + if ((mods[i] + delta) % primes[i] == 0) { + delta += 2; + if (delta > maxdelta) + goto again; + goto loop; + } + } + } else { + for (i = 1; i < NUMPRIMES; i++) { + /* + * check that rnd is not a prime and also that gcd(rnd-1,primes) + * == 1 (except for 2) + */ + if (((mods[i] + delta) % primes[i]) <= 1) { + delta += 2; + if (delta > maxdelta) + goto again; + goto loop; + } } } if (!BN_add_word(rnd, delta)) - return (0); + return 0; + if (BN_num_bits(rnd) != bits) + goto again; bn_check_top(rnd); - return (1); + return 1; } -static int probable_prime_dh(BIGNUM *rnd, int bits, - const BIGNUM *add, const BIGNUM *rem, - BN_CTX *ctx) +int bn_probable_prime_dh(BIGNUM *rnd, int bits, + const BIGNUM *add, const BIGNUM *rem, BN_CTX *ctx) { int i, ret = 0; BIGNUM *t1; @@ -407,7 +362,7 @@ static int probable_prime_dh(BIGNUM *rnd, int bits, if ((t1 = BN_CTX_get(ctx)) == NULL) goto err; - if (!BN_rand(rnd, bits, 0, 1)) + if (!BN_rand(rnd, bits, BN_RAND_TOP_ONE, BN_RAND_BOTTOM_ODD)) goto err; /* we need ((rnd-rem) % add) == 0 */ @@ -426,19 +381,24 @@ static int probable_prime_dh(BIGNUM *rnd, int bits, /* we now have a random number 'rand' to test. */ - loop:for (i = 1; i < NUMPRIMES; i++) { + loop: + for (i = 1; i < NUMPRIMES; i++) { /* check that rnd is a prime */ - if (BN_mod_word(rnd, (BN_ULONG)primes[i]) <= 1) { + BN_ULONG mod = BN_mod_word(rnd, (BN_ULONG)primes[i]); + if (mod == (BN_ULONG)-1) + goto err; + if (mod <= 1) { if (!BN_add(rnd, rnd, add)) goto err; goto loop; } } ret = 1; + err: BN_CTX_end(ctx); bn_check_top(rnd); - return (ret); + return ret; } static int probable_prime_dh_safe(BIGNUM *p, int bits, const BIGNUM *padd, @@ -458,7 +418,7 @@ static int probable_prime_dh_safe(BIGNUM *p, int bits, const BIGNUM *padd, if (!BN_rshift1(qadd, padd)) goto err; - if (!BN_rand(q, bits, 0, 1)) + if (!BN_rand(q, bits, BN_RAND_TOP_ONE, BN_RAND_BOTTOM_ODD)) goto err; /* we need ((rnd-rem) % add) == 0 */ @@ -482,13 +442,17 @@ static int probable_prime_dh_safe(BIGNUM *p, int bits, const BIGNUM *padd, if (!BN_add_word(p, 1)) goto err; - loop:for (i = 1; i < NUMPRIMES; i++) { + loop: + for (i = 1; i < NUMPRIMES; i++) { /* check that p and q are prime */ /* * check that for p and q gcd(p-1,primes) == 1 (except for 2) */ - if ((BN_mod_word(p, (BN_ULONG)primes[i]) == 0) || - (BN_mod_word(q, (BN_ULONG)primes[i]) == 0)) { + BN_ULONG pmod = BN_mod_word(p, (BN_ULONG)primes[i]); + BN_ULONG qmod = BN_mod_word(q, (BN_ULONG)primes[i]); + if (pmod == (BN_ULONG)-1 || qmod == (BN_ULONG)-1) + goto err; + if (pmod == 0 || qmod == 0) { if (!BN_add(p, p, padd)) goto err; if (!BN_add(q, q, qadd)) @@ -497,8 +461,9 @@ static int probable_prime_dh_safe(BIGNUM *p, int bits, const BIGNUM *padd, } } ret = 1; + err: BN_CTX_end(ctx); bn_check_top(p); - return (ret); + return ret; } |