* 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:
* 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
+ * 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
* 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.]
*/
-#include <stdio.h>
-#include "cryptlib.h"
+#include "internal/cryptlib.h"
#include "bn_lcl.h"
/* r can == a or b */
-int BN_add(r, a, b)
-BIGNUM *r;
-BIGNUM *a;
-BIGNUM *b;
- {
- int i;
- BIGNUM *tmp;
-
- /* 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; }
-
- /* we are now a - b */
-
- if (BN_ucmp(a,b) < 0)
- {
- if (bn_wexpand(r,b->top) == NULL) return(0);
- bn_qsub(r,b,a);
- r->neg=1;
- }
- else
- {
- if (bn_wexpand(r,a->top) == NULL) return(0);
- bn_qsub(r,a,b);
- r->neg=0;
- }
- return(1);
- }
-
- if (a->neg) /* both are neg */
- r->neg=1;
- else
- r->neg=0;
-
- i=(a->top > b->top);
-
- if (i)
- {
- if (bn_wexpand(r,a->top+1) == NULL) return(0);
- bn_qadd(r,a,b);
- }
- else
- {
- if (bn_wexpand(r,b->top+1) == NULL) return(0);
- bn_qadd(r,b,a);
- }
- return(1);
- }
-
-/* unsigned add of b to a, r must be large enough */
-void bn_qadd(r,a,b)
-BIGNUM *r;
-BIGNUM *a;
-BIGNUM *b;
- {
- register int i;
- int max,min;
- BN_ULONG *ap,*bp,*rp,carry,t1;
-
- max=a->top;
- min=b->top;
- r->top=max;
-
- ap=a->d;
- bp=b->d;
- rp=r->d;
- carry=0;
-
- carry=bn_add_words(rp,ap,bp,min);
- rp+=min;
- ap+=min;
- bp+=min;
- i=min;
-
- if (carry)
- {
- while (i < max)
- {
- i++;
- t1= *(ap++);
- if ((*(rp++)=(t1+1)&BN_MASK2) >= t1)
- {
- carry=0;
- break;
- }
- }
- if ((i >= max) && carry)
- {
- *(rp++)=1;
- r->top++;
- }
- }
- for (; i<max; i++)
- *(rp++)= *(ap++);
- /* memcpy(rp,ap,sizeof(*ap)*(max-i));*/
- }
+int BN_add(BIGNUM *r, const BIGNUM *a, const BIGNUM *b)
+{
+ const BIGNUM *tmp;
+ 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) {
+ 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;
+ const BIGNUM *tmp;
+
+ bn_check_top(a);
+ bn_check_top(b);
+
+ if (a->top < b->top) {
+ 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;
+ 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++;
+ }
+ }
+ if (dif && rp != ap)
+ while (dif--)
+ /* copy remaining words if ap != rp */
+ *(rp++) = *(ap++);
+ 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;
+ register BN_ULONG t1, t2, *rp;
+ register const BN_ULONG *ap, *bp;
+ int i, carry;
+
+ 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;
+
+#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;
+ }
+ *(rp++) = t1 & BN_MASK2;
+ }
+#else
+ carry = 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 (dif && ap != rp)
+ memcpy(rp, ap, sizeof(*rp) * dif);
+
+ 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;
+ }
+ }
+
+ 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);
+}
projects / openssl.git / blobdiff