4cd640f684
Same rationale as the previous commits.
(cherry picked from commit 422196759f)
Removed the winrt-specific parts.
316 lines
10 KiB
C
316 lines
10 KiB
C
/* crypto/bn/bn_mod.c */
|
|
/*
|
|
* 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.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
*
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* 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
|
|
* the documentation and/or other materials provided with the
|
|
* distribution.
|
|
*
|
|
* 3. All advertising materials mentioning features or use of this
|
|
* software must display the following acknowledgment:
|
|
* "This product includes software developed by the OpenSSL Project
|
|
* for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
|
|
*
|
|
* 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
|
|
* endorse or promote products derived from this software without
|
|
* prior written permission. For written permission, please contact
|
|
* openssl-core@openssl.org.
|
|
*
|
|
* 5. Products derived from this software may not be called "OpenSSL"
|
|
* nor may "OpenSSL" appear in their names without prior written
|
|
* permission of the OpenSSL Project.
|
|
*
|
|
* 6. Redistributions of any form whatsoever must retain the following
|
|
* acknowledgment:
|
|
* "This product includes software developed by the OpenSSL Project
|
|
* for use in the OpenSSL Toolkit (http://www.openssl.org/)"
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
|
|
* EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
|
|
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
|
|
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
|
|
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
|
|
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
|
|
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
|
|
* STRICT 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.
|
|
* ====================================================================
|
|
*
|
|
* This product includes cryptographic software written by Eric Young
|
|
* (eay@cryptsoft.com). This product includes software written by Tim
|
|
* Hudson (tjh@cryptsoft.com).
|
|
*
|
|
*/
|
|
/* 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:
|
|
* 1. Redistributions of source code must retain the copyright
|
|
* 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 the
|
|
* documentation and/or other materials provided with the distribution.
|
|
* 3. All advertising materials mentioning features or use of this software
|
|
* must display the following acknowledgement:
|
|
* "This product includes cryptographic software written by
|
|
* 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
|
|
* 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
|
|
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
|
|
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
* 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 "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);
|
|
}
|
|
|
|
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_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);
|
|
}
|
|
|
|
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);
|
|
}
|
|
|
|
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);
|
|
}
|
|
|
|
/*
|
|
* 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;
|
|
}
|
|
|
|
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 (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 (abs_m)
|
|
BN_free(abs_m);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* 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;
|
|
}
|