-/* crypto/bn/bn_mod.c */
-/* Includes code written by Lenka Fibikova <fibikova@exp-math.uni-essen.de>
- * for the OpenSSL project. */
+/*
+ * Includes code written by Lenka Fibikova <fibikova@exp-math.uni-essen.de>
+ * for the OpenSSL project.
+ */
/* ====================================================================
* Copyright (c) 1998-2000 The OpenSSL Project. All rights reserved.
*
* are met:
*
* 1. Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
+ * notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* 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 "cryptlib.h"
+#include "internal/cryptlib.h"
#include "bn_lcl.h"
-
-#if 0 /* now just a #define */
-int BN_mod(BIGNUM *rem, const BIGNUM *m, const BIGNUM *d, BN_CTX *ctx)
- {
- return(BN_div(NULL,rem,m,d,ctx));
- /* note that rem->neg == m->neg (unless the remainder is zero) */
- }
-#endif
-
-
int BN_nnmod(BIGNUM *r, const BIGNUM *m, const BIGNUM *d, BN_CTX *ctx)
- {
- /* like BN_mod, but returns non-negative remainder
- * (i.e., 0 <= r < |d| always holds) */
-
- if (!(BN_mod(r,m,d,ctx)))
- return 0;
- if (!r->neg)
- return 1;
- /* now -|d| < r < 0, so we have to set r := r + |d| */
- return (d->neg ? BN_sub : BN_add)(r, r, d);
+{
+ /*
+ * like BN_mod, but returns non-negative remainder (i.e., 0 <= r < |d|
+ * always holds)
+ */
+
+ if (!(BN_mod(r, m, d, ctx)))
+ return 0;
+ if (!r->neg)
+ return 1;
+ /* now -|d| < r < 0, so we have to set r := r + |d| */
+ return (d->neg ? BN_sub : BN_add) (r, r, d);
}
+int BN_mod_add(BIGNUM *r, const BIGNUM *a, const BIGNUM *b, const BIGNUM *m,
+ BN_CTX *ctx)
+{
+ if (!BN_add(r, a, b))
+ return 0;
+ return BN_nnmod(r, r, m, ctx);
+}
-int BN_mod_add(BIGNUM *r, const BIGNUM *a, const BIGNUM *b, const BIGNUM *m, BN_CTX *ctx)
- {
- if (!BN_add(r, a, b)) return 0;
- return BN_nnmod(r, r, m, ctx);
- }
-
-
-/* BN_mod_add variant that may be used if both a and b are non-negative
- * and less than m */
-int BN_mod_add_quick(BIGNUM *r, const BIGNUM *a, const BIGNUM *b, const BIGNUM *m)
- {
- if (!BN_uadd(r, a, b)) return 0;
- if (BN_ucmp(r, m) >= 0)
- return BN_usub(r, r, m);
- return 1;
- }
-
-
-int BN_mod_sub(BIGNUM *r, const BIGNUM *a, const BIGNUM *b, const BIGNUM *m, BN_CTX *ctx)
- {
- if (!BN_sub(r, a, b)) return 0;
- return BN_nnmod(r, r, m, ctx);
- }
-
+/*
+ * BN_mod_add variant that may be used if both a and b are non-negative and
+ * less than m
+ */
+int BN_mod_add_quick(BIGNUM *r, const BIGNUM *a, const BIGNUM *b,
+ const BIGNUM *m)
+{
+ if (!BN_uadd(r, a, b))
+ return 0;
+ if (BN_ucmp(r, m) >= 0)
+ return BN_usub(r, r, m);
+ return 1;
+}
-/* BN_mod_sub variant that may be used if both a and b are non-negative
- * and less than m */
-int BN_mod_sub_quick(BIGNUM *r, const BIGNUM *a, const BIGNUM *b, const BIGNUM *m)
- {
- if (!BN_sub(r, a, b)) return 0;
- if (r->neg)
- return BN_add(r, r, m);
- return 1;
- }
+int BN_mod_sub(BIGNUM *r, const BIGNUM *a, const BIGNUM *b, const BIGNUM *m,
+ BN_CTX *ctx)
+{
+ if (!BN_sub(r, a, b))
+ return 0;
+ return BN_nnmod(r, r, m, ctx);
+}
+/*
+ * BN_mod_sub variant that may be used if both a and b are non-negative and
+ * less than m
+ */
+int BN_mod_sub_quick(BIGNUM *r, const BIGNUM *a, const BIGNUM *b,
+ const BIGNUM *m)
+{
+ if (!BN_sub(r, a, b))
+ return 0;
+ if (r->neg)
+ return BN_add(r, r, m);
+ return 1;
+}
/* slow but works */
int BN_mod_mul(BIGNUM *r, const BIGNUM *a, const BIGNUM *b, const BIGNUM *m,
- BN_CTX *ctx)
- {
- BIGNUM *t;
- int ret=0;
-
- bn_check_top(a);
- bn_check_top(b);
- bn_check_top(m);
-
- BN_CTX_start(ctx);
- if ((t = BN_CTX_get(ctx)) == NULL) goto err;
- if (a == b)
- { if (!BN_sqr(t,a,ctx)) goto err; }
- else
- { if (!BN_mul(t,a,b,ctx)) goto err; }
- if (!BN_nnmod(r,t,m,ctx)) goto err;
- bn_check_top(r);
- ret=1;
-err:
- BN_CTX_end(ctx);
- return(ret);
- }
-
+ BN_CTX *ctx)
+{
+ BIGNUM *t;
+ int ret = 0;
+
+ bn_check_top(a);
+ bn_check_top(b);
+ bn_check_top(m);
+
+ BN_CTX_start(ctx);
+ if ((t = BN_CTX_get(ctx)) == NULL)
+ goto err;
+ if (a == b) {
+ if (!BN_sqr(t, a, ctx))
+ goto err;
+ } else {
+ if (!BN_mul(t, a, b, ctx))
+ goto err;
+ }
+ if (!BN_nnmod(r, t, m, ctx))
+ goto err;
+ bn_check_top(r);
+ ret = 1;
+ err:
+ BN_CTX_end(ctx);
+ return (ret);
+}
int BN_mod_sqr(BIGNUM *r, const BIGNUM *a, const BIGNUM *m, BN_CTX *ctx)
- {
- if (!BN_sqr(r, a, ctx)) return 0;
- /* r->neg == 0, thus we don't need BN_nnmod */
- return BN_mod(r, r, m, ctx);
- }
-
+{
+ if (!BN_sqr(r, a, ctx))
+ return 0;
+ /* r->neg == 0, thus we don't need BN_nnmod */
+ return BN_mod(r, r, m, ctx);
+}
int BN_mod_lshift1(BIGNUM *r, const BIGNUM *a, const BIGNUM *m, BN_CTX *ctx)
- {
- if (!BN_lshift1(r, a)) return 0;
- bn_check_top(r);
- return BN_nnmod(r, r, m, ctx);
- }
-
+{
+ if (!BN_lshift1(r, a))
+ return 0;
+ bn_check_top(r);
+ return BN_nnmod(r, r, m, ctx);
+}
-/* BN_mod_lshift1 variant that may be used if a is non-negative
- * and less than m */
+/*
+ * BN_mod_lshift1 variant that may be used if a is non-negative and less than
+ * m
+ */
int BN_mod_lshift1_quick(BIGNUM *r, const BIGNUM *a, const BIGNUM *m)
- {
- if (!BN_lshift1(r, a)) return 0;
- bn_check_top(r);
- if (BN_cmp(r, m) >= 0)
- return BN_sub(r, r, m);
- return 1;
- }
-
+{
+ if (!BN_lshift1(r, a))
+ return 0;
+ bn_check_top(r);
+ if (BN_cmp(r, m) >= 0)
+ return BN_sub(r, r, m);
+ return 1;
+}
-int BN_mod_lshift(BIGNUM *r, const BIGNUM *a, int n, const BIGNUM *m, BN_CTX *ctx)
- {
- BIGNUM *abs_m = NULL;
- int ret;
+int BN_mod_lshift(BIGNUM *r, const BIGNUM *a, int n, const BIGNUM *m,
+ BN_CTX *ctx)
+{
+ BIGNUM *abs_m = NULL;
+ int ret;
- if (!BN_nnmod(r, a, m, ctx)) return 0;
+ if (!BN_nnmod(r, a, m, ctx))
+ return 0;
- if (m->neg)
- {
- abs_m = BN_dup(m);
- if (abs_m == NULL) return 0;
- abs_m->neg = 0;
- }
-
- ret = BN_mod_lshift_quick(r, r, n, (abs_m ? abs_m : m));
- bn_check_top(r);
+ if (m->neg) {
+ abs_m = BN_dup(m);
+ if (abs_m == NULL)
+ return 0;
+ abs_m->neg = 0;
+ }
- if (abs_m)
- BN_free(abs_m);
- return ret;
- }
+ ret = BN_mod_lshift_quick(r, r, n, (abs_m ? abs_m : m));
+ bn_check_top(r);
+ BN_free(abs_m);
+ return ret;
+}
-/* BN_mod_lshift variant that may be used if a is non-negative
- * and less than m */
+/*
+ * BN_mod_lshift variant that may be used if a is non-negative and less than
+ * m
+ */
int BN_mod_lshift_quick(BIGNUM *r, const BIGNUM *a, int n, const BIGNUM *m)
- {
- if (r != a)
- {
- if (BN_copy(r, a) == NULL) return 0;
- }
-
- while (n > 0)
- {
- int max_shift;
-
- /* 0 < r < m */
- max_shift = BN_num_bits(m) - BN_num_bits(r);
- /* max_shift >= 0 */
-
- if (max_shift < 0)
- {
- BNerr(BN_F_BN_MOD_LSHIFT_QUICK, BN_R_INPUT_NOT_REDUCED);
- return 0;
- }
-
- if (max_shift > n)
- max_shift = n;
-
- if (max_shift)
- {
- if (!BN_lshift(r, r, max_shift)) return 0;
- n -= max_shift;
- }
- else
- {
- if (!BN_lshift1(r, r)) return 0;
- --n;
- }
-
- /* BN_num_bits(r) <= BN_num_bits(m) */
-
- if (BN_cmp(r, m) >= 0)
- {
- if (!BN_sub(r, r, m)) return 0;
- }
- }
- bn_check_top(r);
-
- return 1;
- }
+{
+ if (r != a) {
+ if (BN_copy(r, a) == NULL)
+ return 0;
+ }
+
+ while (n > 0) {
+ int max_shift;
+
+ /* 0 < r < m */
+ max_shift = BN_num_bits(m) - BN_num_bits(r);
+ /* max_shift >= 0 */
+
+ if (max_shift < 0) {
+ BNerr(BN_F_BN_MOD_LSHIFT_QUICK, BN_R_INPUT_NOT_REDUCED);
+ return 0;
+ }
+
+ if (max_shift > n)
+ max_shift = n;
+
+ if (max_shift) {
+ if (!BN_lshift(r, r, max_shift))
+ return 0;
+ n -= max_shift;
+ } else {
+ if (!BN_lshift1(r, r))
+ return 0;
+ --n;
+ }
+
+ /* BN_num_bits(r) <= BN_num_bits(m) */
+
+ if (BN_cmp(r, m) >= 0) {
+ if (!BN_sub(r, r, m))
+ return 0;
+ }
+ }
+ bn_check_top(r);
+
+ return 1;
+}
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