-/* crypto/bn/bn_word.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"
-BN_ULONG BN_mod_word(a, w)
-BIGNUM *a;
-unsigned long w;
- {
+BN_ULONG BN_mod_word(const BIGNUM *a, BN_ULONG w)
+{
#ifndef BN_LLONG
- BN_ULONG ret=0;
+ BN_ULONG ret = 0;
#else
- BN_ULLONG ret=0;
+ BN_ULLONG ret = 0;
#endif
- int i;
+ int i;
- w&=BN_MASK2;
- for (i=a->top-1; i>=0; i--)
- {
+ if (w == 0)
+ return (BN_ULONG)-1;
+
+ bn_check_top(a);
+ w &= BN_MASK2;
+ for (i = a->top - 1; i >= 0; i--) {
#ifndef BN_LLONG
- ret=((ret<<BN_BITS4)|((a->d[i]>>BN_BITS4)&BN_MASK2l))%(unsigned long)w;
- ret=((ret<<BN_BITS4)|(a->d[i]&BN_MASK2l))%(unsigned long)w;
+ ret = ((ret << BN_BITS4) | ((a->d[i] >> BN_BITS4) & BN_MASK2l)) % w;
+ ret = ((ret << BN_BITS4) | (a->d[i] & BN_MASK2l)) % w;
#else
- ret=(BN_ULLONG)(((ret<<(BN_ULLONG)BN_BITS2)|a->d[i])%
- (BN_ULLONG)w);
+ ret = (BN_ULLONG) (((ret << (BN_ULLONG) BN_BITS2) | a->d[i]) %
+ (BN_ULLONG) w);
#endif
- }
- return((BN_ULONG)ret);
- }
-
-BN_ULONG BN_div_word(a, w)
-BIGNUM *a;
-unsigned long w;
- {
- BN_ULONG ret;
- int i;
-
- if (a->top == 0) return(0);
- ret=0;
- w&=BN_MASK2;
- for (i=a->top-1; i>=0; i--)
- {
- BN_ULONG l,d;
-
- l=a->d[i];
- d=bn_div64(ret,l,w);
- ret=(l-((d*w)&BN_MASK2))&BN_MASK2;
- a->d[i]=d;
- }
- if (a->d[a->top-1] == 0)
- a->top--;
- return(ret);
- }
-
-int BN_add_word(a, w)
-BIGNUM *a;
-unsigned long w;
- {
- BN_ULONG l;
- int i;
-
- if (a->neg)
- {
- a->neg=0;
- i=BN_sub_word(a,w);
- if (!BN_is_zero(a))
- a->neg=1;
- return(i);
- }
- w&=BN_MASK2;
- if (bn_wexpand(a,a->top+1) == NULL) return(0);
- i=0;
- for (;;)
- {
- l=(a->d[i]+(BN_ULONG)w)&BN_MASK2;
- a->d[i]=l;
- if (w > l)
- w=1;
- else
- break;
- i++;
- }
- if (i >= a->top)
- a->top++;
- return(1);
- }
-
-int BN_sub_word(a, w)
-BIGNUM *a;
-unsigned long w;
- {
- int i;
-
- if (a->neg)
- {
- a->neg=0;
- i=BN_add_word(a,w);
- a->neg=1;
- return(i);
- }
-
- w&=BN_MASK2;
- if ((a->top == 1) && (a->d[0] < w))
- {
- a->d[0]=w-a->d[0];
- a->neg=1;
- return(1);
- }
- i=0;
- for (;;)
- {
- if (a->d[i] >= w)
- {
- a->d[i]-=w;
- break;
- }
- else
- {
- a->d[i]=(a->d[i]-w)&BN_MASK2;
- i++;
- w=1;
- }
- }
- if ((a->d[i] == 0) && (i == (a->top-1)))
- a->top--;
- return(1);
- }
-
-int BN_mul_word(a,w)
-BIGNUM *a;
-unsigned long w;
- {
- BN_ULONG ll;
-
- w&=BN_MASK2;
- if (a->top)
- {
- ll=bn_mul_words(a->d,a->d,a->top,w);
- if (ll)
- {
- if (bn_wexpand(a,a->top+1) == NULL) return(0);
- a->d[a->top++]=ll;
- }
- }
- return(0);
- }
+ }
+ return ((BN_ULONG)ret);
+}
+
+BN_ULONG BN_div_word(BIGNUM *a, BN_ULONG w)
+{
+ BN_ULONG ret = 0;
+ int i, j;
+
+ bn_check_top(a);
+ w &= BN_MASK2;
+
+ if (!w)
+ /* actually this an error (division by zero) */
+ return (BN_ULONG)-1;
+ if (a->top == 0)
+ return 0;
+
+ /* normalize input (so bn_div_words doesn't complain) */
+ j = BN_BITS2 - BN_num_bits_word(w);
+ w <<= j;
+ if (!BN_lshift(a, a, j))
+ return (BN_ULONG)-1;
+
+ for (i = a->top - 1; i >= 0; i--) {
+ BN_ULONG l, d;
+
+ l = a->d[i];
+ d = bn_div_words(ret, l, w);
+ ret = (l - ((d * w) & BN_MASK2)) & BN_MASK2;
+ a->d[i] = d;
+ }
+ if ((a->top > 0) && (a->d[a->top - 1] == 0))
+ a->top--;
+ ret >>= j;
+ bn_check_top(a);
+ return (ret);
+}
+
+int BN_add_word(BIGNUM *a, BN_ULONG w)
+{
+ BN_ULONG l;
+ int i;
+
+ bn_check_top(a);
+ w &= BN_MASK2;
+
+ /* degenerate case: w is zero */
+ if (!w)
+ return 1;
+ /* degenerate case: a is zero */
+ if (BN_is_zero(a))
+ return BN_set_word(a, w);
+ /* handle 'a' when negative */
+ if (a->neg) {
+ a->neg = 0;
+ i = BN_sub_word(a, w);
+ if (!BN_is_zero(a))
+ a->neg = !(a->neg);
+ return (i);
+ }
+ for (i = 0; w != 0 && i < a->top; i++) {
+ a->d[i] = l = (a->d[i] + w) & BN_MASK2;
+ w = (w > l) ? 1 : 0;
+ }
+ if (w && i == a->top) {
+ if (bn_wexpand(a, a->top + 1) == NULL)
+ return 0;
+ a->top++;
+ a->d[i] = w;
+ }
+ bn_check_top(a);
+ return (1);
+}
+
+int BN_sub_word(BIGNUM *a, BN_ULONG w)
+{
+ int i;
+
+ bn_check_top(a);
+ w &= BN_MASK2;
+
+ /* degenerate case: w is zero */
+ if (!w)
+ return 1;
+ /* degenerate case: a is zero */
+ if (BN_is_zero(a)) {
+ i = BN_set_word(a, w);
+ if (i != 0)
+ BN_set_negative(a, 1);
+ return i;
+ }
+ /* handle 'a' when negative */
+ if (a->neg) {
+ a->neg = 0;
+ i = BN_add_word(a, w);
+ a->neg = 1;
+ return (i);
+ }
+
+ if ((a->top == 1) && (a->d[0] < w)) {
+ a->d[0] = w - a->d[0];
+ a->neg = 1;
+ return (1);
+ }
+ i = 0;
+ for (;;) {
+ if (a->d[i] >= w) {
+ a->d[i] -= w;
+ break;
+ } else {
+ a->d[i] = (a->d[i] - w) & BN_MASK2;
+ i++;
+ w = 1;
+ }
+ }
+ if ((a->d[i] == 0) && (i == (a->top - 1)))
+ a->top--;
+ bn_check_top(a);
+ return (1);
+}
+
+int BN_mul_word(BIGNUM *a, BN_ULONG w)
+{
+ BN_ULONG ll;
+ bn_check_top(a);
+ w &= BN_MASK2;
+ if (a->top) {
+ if (w == 0)
+ BN_zero(a);
+ else {
+ ll = bn_mul_words(a->d, a->d, a->top, w);
+ if (ll) {
+ if (bn_wexpand(a, a->top + 1) == NULL)
+ return (0);
+ a->d[a->top++] = ll;
+ }
+ }
+ }
+ bn_check_top(a);
+ return (1);
+}
projects / openssl.git / blobdiff