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authorWojtek Kosior <wk@koszkonutek-tmp.pl.eu.org>2021-04-30 00:33:56 +0200
committerWojtek Kosior <wk@koszkonutek-tmp.pl.eu.org>2021-04-30 00:33:56 +0200
commitaa4d426b4d3527d7e166df1a05058c9a4a0f6683 (patch)
tree4ff17ce8b89a2321b9d0ed4bcfc37c447bcb6820 /openssl-1.1.0h/crypto/bn/bn_add.c
downloadsmtps-and-pop3s-console-program-master.tar.gz
smtps-and-pop3s-console-program-master.zip
initial/final commitHEADmaster
Diffstat (limited to 'openssl-1.1.0h/crypto/bn/bn_add.c')
-rw-r--r--openssl-1.1.0h/crypto/bn/bn_add.c209
1 files changed, 209 insertions, 0 deletions
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;
+}