-/* crypto/bn/bn_shift.c */
/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
* 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:
* 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"
-int BN_lshift1(BIGNUM *r, BIGNUM *a)
- {
- register BN_ULONG *ap,*rp,t,c;
- int i;
-
- if (r != a)
- {
- r->neg=a->neg;
- if (bn_wexpand(r,a->top+1) == NULL) return(0);
- r->top=a->top;
- }
- else
- {
- if (bn_wexpand(r,a->top+1) == NULL) return(0);
- }
- ap=a->d;
- rp=r->d;
- c=0;
- for (i=0; i<a->top; i++)
- {
- t= *(ap++);
- *(rp++)=((t<<1)|c)&BN_MASK2;
- c=(t & BN_TBIT)?1:0;
- }
- if (c)
- {
- *rp=1;
- r->top++;
- }
- return(1);
- }
-
-int BN_rshift1(BIGNUM *r, BIGNUM *a)
- {
- BN_ULONG *ap,*rp,t,c;
- int i;
-
- if (BN_is_zero(a))
- {
- BN_zero(r);
- return(1);
- }
- if (a != r)
- {
- if (bn_wexpand(r,a->top) == NULL) return(0);
- r->top=a->top;
- r->neg=a->neg;
- }
- ap=a->d;
- rp=r->d;
- c=0;
- for (i=a->top-1; i>=0; i--)
- {
- t=ap[i];
- rp[i]=((t>>1)&BN_MASK2)|c;
- c=(t&1)?BN_TBIT:0;
- }
- bn_fix_top(r);
- return(1);
- }
+int BN_lshift1(BIGNUM *r, const BIGNUM *a)
+{
+ register BN_ULONG *ap, *rp, t, c;
+ int i;
+
+ bn_check_top(r);
+ bn_check_top(a);
+
+ if (r != a) {
+ r->neg = a->neg;
+ if (bn_wexpand(r, a->top + 1) == NULL)
+ return (0);
+ r->top = a->top;
+ } else {
+ if (bn_wexpand(r, a->top + 1) == NULL)
+ return (0);
+ }
+ ap = a->d;
+ rp = r->d;
+ c = 0;
+ for (i = 0; i < a->top; i++) {
+ t = *(ap++);
+ *(rp++) = ((t << 1) | c) & BN_MASK2;
+ c = (t & BN_TBIT) ? 1 : 0;
+ }
+ if (c) {
+ *rp = 1;
+ r->top++;
+ }
+ bn_check_top(r);
+ return (1);
+}
+
+int BN_rshift1(BIGNUM *r, const BIGNUM *a)
+{
+ BN_ULONG *ap, *rp, t, c;
+ int i, j;
+
+ bn_check_top(r);
+ bn_check_top(a);
+
+ if (BN_is_zero(a)) {
+ BN_zero(r);
+ return (1);
+ }
+ i = a->top;
+ ap = a->d;
+ j = i - (ap[i - 1] == 1);
+ if (a != r) {
+ if (bn_wexpand(r, j) == NULL)
+ return (0);
+ r->neg = a->neg;
+ }
+ rp = r->d;
+ t = ap[--i];
+ c = (t & 1) ? BN_TBIT : 0;
+ if (t >>= 1)
+ rp[i] = t;
+ while (i > 0) {
+ t = ap[--i];
+ rp[i] = ((t >> 1) & BN_MASK2) | c;
+ c = (t & 1) ? BN_TBIT : 0;
+ }
+ r->top = j;
+ bn_check_top(r);
+ return (1);
+}
int BN_lshift(BIGNUM *r, const BIGNUM *a, int n)
- {
- int i,nw,lb,rb;
- BN_ULONG *t,*f;
- BN_ULONG l;
-
- r->neg=a->neg;
- if (bn_wexpand(r,a->top+(n/BN_BITS2)+1) == NULL) return(0);
- nw=n/BN_BITS2;
- lb=n%BN_BITS2;
- rb=BN_BITS2-lb;
- f=a->d;
- t=r->d;
- t[a->top+nw]=0;
- if (lb == 0)
- for (i=a->top-1; i>=0; i--)
- t[nw+i]=f[i];
- else
- for (i=a->top-1; i>=0; i--)
- {
- l=f[i];
- t[nw+i+1]|=(l>>rb)&BN_MASK2;
- t[nw+i]=(l<<lb)&BN_MASK2;
- }
- memset(t,0,nw*sizeof(t[0]));
-/* for (i=0; i<nw; i++)
- t[i]=0;*/
- r->top=a->top+nw+1;
- bn_fix_top(r);
- return(1);
- }
-
-int BN_rshift(BIGNUM *r, BIGNUM *a, int n)
- {
- int i,j,nw,lb,rb;
- BN_ULONG *t,*f;
- BN_ULONG l,tmp;
-
- nw=n/BN_BITS2;
- rb=n%BN_BITS2;
- lb=BN_BITS2-rb;
- if (nw > a->top || a->top == 0)
- {
- BN_zero(r);
- return(1);
- }
- if (r != a)
- {
- r->neg=a->neg;
- if (bn_wexpand(r,a->top-nw+1) == NULL) return(0);
- }
-
- f= &(a->d[nw]);
- t=r->d;
- j=a->top-nw;
- r->top=j;
-
- if (rb == 0)
- {
- for (i=j+1; i > 0; i--)
- *(t++)= *(f++);
- }
- else
- {
- l= *(f++);
- for (i=1; i<j; i++)
- {
- tmp =(l>>rb)&BN_MASK2;
- l= *(f++);
- *(t++) =(tmp|(l<<lb))&BN_MASK2;
- }
- *(t++) =(l>>rb)&BN_MASK2;
- }
- *t=0;
- bn_fix_top(r);
- return(1);
- }
+{
+ int i, nw, lb, rb;
+ BN_ULONG *t, *f;
+ BN_ULONG l;
+
+ bn_check_top(r);
+ bn_check_top(a);
+
+ if (n < 0) {
+ BNerr(BN_F_BN_LSHIFT, BN_R_INVALID_SHIFT);
+ return 0;
+ }
+
+ r->neg = a->neg;
+ nw = n / BN_BITS2;
+ if (bn_wexpand(r, a->top + nw + 1) == NULL)
+ return (0);
+ lb = n % BN_BITS2;
+ rb = BN_BITS2 - lb;
+ f = a->d;
+ t = r->d;
+ t[a->top + nw] = 0;
+ if (lb == 0)
+ for (i = a->top - 1; i >= 0; i--)
+ t[nw + i] = f[i];
+ else
+ for (i = a->top - 1; i >= 0; i--) {
+ l = f[i];
+ t[nw + i + 1] |= (l >> rb) & BN_MASK2;
+ t[nw + i] = (l << lb) & BN_MASK2;
+ }
+ memset(t, 0, sizeof(*t) * nw);
+ r->top = a->top + nw + 1;
+ bn_correct_top(r);
+ bn_check_top(r);
+ return (1);
+}
+
+int BN_rshift(BIGNUM *r, const BIGNUM *a, int n)
+{
+ int i, j, nw, lb, rb;
+ BN_ULONG *t, *f;
+ BN_ULONG l, tmp;
+
+ bn_check_top(r);
+ bn_check_top(a);
+
+ if (n < 0) {
+ BNerr(BN_F_BN_RSHIFT, BN_R_INVALID_SHIFT);
+ return 0;
+ }
+
+ nw = n / BN_BITS2;
+ rb = n % BN_BITS2;
+ lb = BN_BITS2 - rb;
+ if (nw >= a->top || a->top == 0) {
+ BN_zero(r);
+ return (1);
+ }
+ i = (BN_num_bits(a) - n + (BN_BITS2 - 1)) / BN_BITS2;
+ if (r != a) {
+ r->neg = a->neg;
+ if (bn_wexpand(r, i) == NULL)
+ return (0);
+ } else {
+ if (n == 0)
+ return 1; /* or the copying loop will go berserk */
+ }
+
+ f = &(a->d[nw]);
+ t = r->d;
+ j = a->top - nw;
+ r->top = i;
+
+ if (rb == 0) {
+ for (i = j; i != 0; i--)
+ *(t++) = *(f++);
+ } else {
+ l = *(f++);
+ for (i = j - 1; i != 0; i--) {
+ tmp = (l >> rb) & BN_MASK2;
+ l = *(f++);
+ *(t++) = (tmp | (l << lb)) & BN_MASK2;
+ }
+ if ((l = (l >> rb) & BN_MASK2))
+ *(t) = l;
+ }
+ bn_check_top(r);
+ return (1);
+}
projects / openssl.git / blobdiff