From aa4d426b4d3527d7e166df1a05058c9a4a0f6683 Mon Sep 17 00:00:00 2001 From: Wojtek Kosior Date: Fri, 30 Apr 2021 00:33:56 +0200 Subject: initial/final commit --- openssl-1.1.0h/crypto/bn/bn_add.c | 209 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 209 insertions(+) create mode 100644 openssl-1.1.0h/crypto/bn/bn_add.c (limited to 'openssl-1.1.0h/crypto/bn/bn_add.c') diff --git a/openssl-1.1.0h/crypto/bn/bn_add.c b/openssl-1.1.0h/crypto/bn/bn_add.c new file mode 100644 index 0000000..7cdefa7 --- /dev/null +++ b/openssl-1.1.0h/crypto/bn/bn_add.c @@ -0,0 +1,209 @@ +/* + * Copyright 1995-2016 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 "internal/cryptlib.h" +#include "bn_lcl.h" + +/* r can == a or b */ +int BN_add(BIGNUM *r, const BIGNUM *a, const BIGNUM *b) +{ + int a_neg = a->neg, ret; + + 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) { + const BIGNUM *tmp; + + tmp = a; + a = b; + b = tmp; + } + + /* we are now a - b */ + + 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; + } + return 1; + } + + ret = BN_uadd(r, a, b); + r->neg = a_neg; + bn_check_top(r); + return ret; +} + +/* unsigned add of b to a */ +int BN_uadd(BIGNUM *r, const BIGNUM *a, const BIGNUM *b) +{ + int max, min, dif; + 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; + } + max = a->top; + min = b->top; + dif = max - min; + + if (bn_wexpand(r, max + 1) == NULL) + return 0; + + r->top = max; + + ap = a->d; + bp = b->d; + rp = r->d; + + carry = bn_add_words(rp, ap, bp, min); + rp += min; + ap += min; + + while (dif) { + dif--; + t1 = *(ap++); + t2 = (t1 + carry) & BN_MASK2; + *(rp++) = t2; + carry &= (t2 == 0); + } + *rp = carry; + r->top += carry; + + r->neg = 0; + bn_check_top(r); + return 1; +} + +/* unsigned subtraction of b from a, a must be larger than b. */ +int BN_usub(BIGNUM *r, const BIGNUM *a, const BIGNUM *b) +{ + int max, min, dif; + BN_ULONG t1, t2, borrow, *rp; + const BN_ULONG *ap, *bp; + + bn_check_top(a); + bn_check_top(b); + + max = a->top; + min = b->top; + dif = max - min; + + if (dif < 0) { /* hmm... should not be happening */ + BNerr(BN_F_BN_USUB, BN_R_ARG2_LT_ARG3); + return 0; + } + + if (bn_wexpand(r, max) == NULL) + return 0; + + ap = a->d; + bp = b->d; + rp = r->d; + + borrow = bn_sub_words(rp, ap, bp, min); + ap += min; + rp += min; + + while (dif) { + dif--; + t1 = *(ap++); + t2 = (t1 - borrow) & BN_MASK2; + *(rp++) = t2; + borrow &= (t1 == 0); + } + + while (max && *--rp == 0) + max--; + + r->top = max; + r->neg = 0; + bn_pollute(r); + + return 1; +} + +int BN_sub(BIGNUM *r, const BIGNUM *a, const BIGNUM *b) +{ + int max; + int add = 0, neg = 0; + + 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) { + const BIGNUM *tmp; + + tmp = a; + a = b; + b = tmp; + } else { + add = 1; + neg = 1; + } + } else { + if (b->neg) { + add = 1; + neg = 0; + } + } + + if (add) { + if (!BN_uadd(r, a, b)) + return 0; + r->neg = neg; + return 1; + } + + /* We are actually doing a - b :-) */ + + 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; +} -- cgit v1.2.3