diff options
author | Jung-uk Kim <jkim@FreeBSD.org> | 2018-09-13 19:18:07 +0000 |
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committer | Jung-uk Kim <jkim@FreeBSD.org> | 2018-09-13 19:18:07 +0000 |
commit | a43ce912fc025d11e1395506111f75fc194d7ba5 (patch) | |
tree | 9794cf7720d75938ed0ea4f499c0dcd4b6eacdda /crypto/bn/bn_add.c | |
parent | 02be298e504b8554caca6dc85af450e1ea44d19d (diff) | |
download | src-test2-a43ce912fc025d11e1395506111f75fc194d7ba5.tar.gz src-test2-a43ce912fc025d11e1395506111f75fc194d7ba5.zip |
Notes
Diffstat (limited to 'crypto/bn/bn_add.c')
-rw-r--r-- | crypto/bn/bn_add.c | 310 |
1 files changed, 84 insertions, 226 deletions
diff --git a/crypto/bn/bn_add.c b/crypto/bn/bn_add.c index 2f3d11044990..f2736b8f6d41 100644 --- a/crypto/bn/bn_add.c +++ b/crypto/bn/bn_add.c @@ -1,119 +1,90 @@ -/* crypto/bn/bn_add.c */ -/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) - * All rights reserved. +/* + * Copyright 1995-2018 The OpenSSL Project Authors. 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.] + * 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 "cryptlib.h" +#include "internal/cryptlib.h" #include "bn_lcl.h" -/* r can == a or b */ +/* signed add of b to a. */ int BN_add(BIGNUM *r, const BIGNUM *a, const BIGNUM *b) { - const BIGNUM *tmp; - int a_neg = a->neg, ret; + int ret, r_neg, cmp_res; bn_check_top(a); bn_check_top(b); - /*- - * a + b a+b - * a + -b a-b - * -a + b b-a - * -a + -b -(a+b) - */ - if (a_neg ^ b->neg) { - /* only one is negative */ - if (a_neg) { - tmp = a; - a = b; - b = tmp; + if (a->neg == b->neg) { + r_neg = a->neg; + ret = BN_uadd(r, a, b); + } else { + cmp_res = BN_ucmp(a, b); + if (cmp_res > 0) { + r_neg = a->neg; + ret = BN_usub(r, a, b); + } else if (cmp_res < 0) { + r_neg = b->neg; + ret = BN_usub(r, b, a); + } else { + r_neg = 0; + BN_zero(r); + ret = 1; } + } - /* we are now a - b */ + r->neg = r_neg; + bn_check_top(r); + return ret; +} - if (BN_ucmp(a, b) < 0) { - if (!BN_usub(r, b, a)) - return (0); - r->neg = 1; +/* signed sub of b from a. */ +int BN_sub(BIGNUM *r, const BIGNUM *a, const BIGNUM *b) +{ + int ret, r_neg, cmp_res; + + bn_check_top(a); + bn_check_top(b); + + if (a->neg != b->neg) { + r_neg = a->neg; + ret = BN_uadd(r, a, b); + } else { + cmp_res = BN_ucmp(a, b); + if (cmp_res > 0) { + r_neg = a->neg; + ret = BN_usub(r, a, b); + } else if (cmp_res < 0) { + r_neg = !b->neg; + ret = BN_usub(r, b, a); } else { - if (!BN_usub(r, a, b)) - return (0); - r->neg = 0; + r_neg = 0; + BN_zero(r); + ret = 1; } - return (1); } - ret = BN_uadd(r, a, b); - r->neg = a_neg; + r->neg = r_neg; bn_check_top(r); return ret; } -/* unsigned add of b to a */ +/* unsigned add of b to a, r can be equal to a or b. */ int BN_uadd(BIGNUM *r, const BIGNUM *a, const BIGNUM *b) { int max, min, dif; - BN_ULONG *ap, *bp, *rp, carry, t1, t2; - const BIGNUM *tmp; + const BN_ULONG *ap, *bp; + BN_ULONG *rp, carry, t1, t2; bn_check_top(a); bn_check_top(b); if (a->top < b->top) { + const BIGNUM *tmp; + tmp = a; a = b; b = tmp; @@ -134,29 +105,17 @@ int BN_uadd(BIGNUM *r, const BIGNUM *a, const BIGNUM *b) carry = bn_add_words(rp, ap, bp, min); rp += min; ap += min; - bp += min; - if (carry) { - while (dif) { - dif--; - t1 = *(ap++); - t2 = (t1 + 1) & BN_MASK2; - *(rp++) = t2; - if (t2) { - carry = 0; - break; - } - } - if (carry) { - /* carry != 0 => dif == 0 */ - *rp = 1; - r->top++; - } + while (dif) { + dif--; + t1 = *(ap++); + t2 = (t1 + carry) & BN_MASK2; + *(rp++) = t2; + carry &= (t2 == 0); } - if (dif && rp != ap) - while (dif--) - /* copy remaining words if ap != rp */ - *(rp++) = *(ap++); + *rp = carry; + r->top += carry; + r->neg = 0; bn_check_top(r); return 1; @@ -166,11 +125,8 @@ int BN_uadd(BIGNUM *r, const BIGNUM *a, const BIGNUM *b) int BN_usub(BIGNUM *r, const BIGNUM *a, const BIGNUM *b) { int max, min, dif; - register BN_ULONG t1, t2, *ap, *bp, *rp; - int i, carry; -#if defined(IRIX_CC_BUG) && !defined(LINT) - int dummy; -#endif + BN_ULONG t1, t2, borrow, *rp; + const BN_ULONG *ap, *bp; bn_check_top(a); bn_check_top(b); @@ -181,133 +137,35 @@ int BN_usub(BIGNUM *r, const BIGNUM *a, const BIGNUM *b) if (dif < 0) { /* hmm... should not be happening */ BNerr(BN_F_BN_USUB, BN_R_ARG2_LT_ARG3); - return (0); + return 0; } if (bn_wexpand(r, max) == NULL) - return (0); + return 0; ap = a->d; bp = b->d; rp = r->d; -#if 1 - carry = 0; - for (i = min; i != 0; i--) { - t1 = *(ap++); - t2 = *(bp++); - if (carry) { - carry = (t1 <= t2); - t1 = (t1 - t2 - 1) & BN_MASK2; - } else { - carry = (t1 < t2); - t1 = (t1 - t2) & BN_MASK2; - } -# if defined(IRIX_CC_BUG) && !defined(LINT) - dummy = t1; -# endif - *(rp++) = t1 & BN_MASK2; - } -#else - carry = bn_sub_words(rp, ap, bp, min); + borrow = bn_sub_words(rp, ap, bp, min); ap += min; - bp += min; rp += min; -#endif - if (carry) { /* subtracted */ - if (!dif) - /* error: a < b */ - return 0; - while (dif) { - dif--; - t1 = *(ap++); - t2 = (t1 - 1) & BN_MASK2; - *(rp++) = t2; - if (t1) - break; - } - } -#if 0 - memcpy(rp, ap, sizeof(*rp) * (max - i)); -#else - if (rp != ap) { - for (;;) { - if (!dif--) - break; - rp[0] = ap[0]; - if (!dif--) - break; - rp[1] = ap[1]; - if (!dif--) - break; - rp[2] = ap[2]; - if (!dif--) - break; - rp[3] = ap[3]; - rp += 4; - ap += 4; - } - } -#endif - - r->top = max; - r->neg = 0; - bn_correct_top(r); - return (1); -} - -int BN_sub(BIGNUM *r, const BIGNUM *a, const BIGNUM *b) -{ - int max; - int add = 0, neg = 0; - const BIGNUM *tmp; - - bn_check_top(a); - bn_check_top(b); - /*- - * a - b a-b - * a - -b a+b - * -a - b -(a+b) - * -a - -b b-a - */ - if (a->neg) { - if (b->neg) { - tmp = a; - a = b; - b = tmp; - } else { - add = 1; - neg = 1; - } - } else { - if (b->neg) { - add = 1; - neg = 0; - } + while (dif) { + dif--; + t1 = *(ap++); + t2 = (t1 - borrow) & BN_MASK2; + *(rp++) = t2; + borrow &= (t1 == 0); } - if (add) { - if (!BN_uadd(r, a, b)) - return (0); - r->neg = neg; - return (1); - } + while (max && *--rp == 0) + max--; - /* We are actually doing a - b :-) */ + r->top = max; + r->neg = 0; + bn_pollute(r); - max = (a->top > b->top) ? a->top : b->top; - if (bn_wexpand(r, max) == NULL) - return (0); - if (BN_ucmp(a, b) < 0) { - if (!BN_usub(r, b, a)) - return (0); - r->neg = 1; - } else { - if (!BN_usub(r, a, b)) - return (0); - r->neg = 0; - } - bn_check_top(r); - return (1); + return 1; } + |