* [including the GNU Public Licence.]
*/
+#define OPENSSL_FIPSAPI
+
#include <stdio.h>
#include "cryptlib.h"
#include "bn_lcl.h"
/* r can == a or b */
-int BN_add(r, a, b)
-BIGNUM *r;
-BIGNUM *a;
-BIGNUM *b;
+int BN_add(BIGNUM *r, const BIGNUM *a, const BIGNUM *b)
{
- int i;
- BIGNUM *tmp;
+ 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)
+ if (a_neg ^ b->neg)
{
/* only one is negative */
- if (a->neg)
+ 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);
+ if (!BN_usub(r,b,a)) return(0);
r->neg=1;
}
else
{
- if (bn_wexpand(r,a->top) == NULL) return(0);
- bn_qsub(r,a,b);
+ if (!BN_usub(r,a,b)) return(0);
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);
+ ret = BN_uadd(r,a,b);
+ r->neg = a_neg;
+ bn_check_top(r);
+ return ret;
}
-/* unsigned add of b to a, r must be large enough */
-void bn_qadd(r,a,b)
-BIGNUM *r;
-BIGNUM *a;
-BIGNUM *b;
+/* unsigned add of b to a */
+int BN_uadd(BIGNUM *r, const BIGNUM *a, const BIGNUM *b)
{
- register int i;
- int max,min;
- BN_ULONG *ap,*bp,*rp,carry,t1;
+ int max,min,dif;
+ BN_ULONG *ap,*bp,*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;
- 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)
+ while (dif)
{
- i++;
- t1= *(ap++);
- if ((*(rp++)=(t1+1)&BN_MASK2) >= t1)
+ dif--;
+ t1 = *(ap++);
+ t2 = (t1+1) & BN_MASK2;
+ *(rp++) = t2;
+ if (t2)
{
carry=0;
break;
}
}
- if ((i >= max) && carry)
+ if (carry)
{
- *(rp++)=1;
+ /* carry != 0 => dif == 0 */
+ *rp = 1;
r->top++;
}
}
- for (; i<max; i++)
- *(rp++)= *(ap++);
- /* memcpy(rp,ap,sizeof(*ap)*(max-i));*/
+ 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,*ap,*bp,*rp;
+ int i,carry;
+#if defined(IRIX_CC_BUG) && !defined(LINT)
+ int dummy;
+#endif
+
+ 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;
+ }
+#if defined(IRIX_CC_BUG) && !defined(LINT)
+ dummy=t1;
+#endif
+ *(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 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; }
+ }
+
+ 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