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1301 lines
34 KiB
1301 lines
34 KiB
/* crypto/bn/bn_gf2m.c */ |
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/* ==================================================================== |
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* Copyright 2002 Sun Microsystems, Inc. ALL RIGHTS RESERVED. |
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* |
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* The Elliptic Curve Public-Key Crypto Library (ECC Code) included |
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* herein is developed by SUN MICROSYSTEMS, INC., and is contributed |
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* to the OpenSSL project. |
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* |
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* The ECC Code is licensed pursuant to the OpenSSL open source |
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* license provided below. |
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* |
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* In addition, Sun covenants to all licensees who provide a reciprocal |
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* covenant with respect to their own patents if any, not to sue under |
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* current and future patent claims necessarily infringed by the making, |
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* using, practicing, selling, offering for sale and/or otherwise |
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* disposing of the ECC Code as delivered hereunder (or portions thereof), |
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* provided that such covenant shall not apply: |
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* 1) for code that a licensee deletes from the ECC Code; |
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* 2) separates from the ECC Code; or |
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* 3) for infringements caused by: |
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* i) the modification of the ECC Code or |
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* ii) the combination of the ECC Code with other software or |
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* devices where such combination causes the infringement. |
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* |
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* The software is originally written by Sheueling Chang Shantz and |
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* Douglas Stebila of Sun Microsystems Laboratories. |
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* |
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*/ |
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|
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/* |
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* NOTE: This file is licensed pursuant to the OpenSSL license below and may |
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* be modified; but after modifications, the above covenant may no longer |
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* apply! In such cases, the corresponding paragraph ["In addition, Sun |
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* covenants ... causes the infringement."] and this note can be edited out; |
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* but please keep the Sun copyright notice and attribution. |
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*/ |
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|
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/* ==================================================================== |
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* Copyright (c) 1998-2002 The OpenSSL Project. All rights reserved. |
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* |
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* Redistribution and use in source and binary forms, with or without |
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* modification, are permitted provided that the following conditions |
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* are met: |
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* |
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* 1. Redistributions of source code must retain the above copyright |
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* notice, this list of conditions and the following disclaimer. |
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* |
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* 2. Redistributions in binary form must reproduce the above copyright |
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* notice, this list of conditions and the following disclaimer in |
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* the documentation and/or other materials provided with the |
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* distribution. |
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* |
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* 3. All advertising materials mentioning features or use of this |
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* software must display the following acknowledgment: |
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* "This product includes software developed by the OpenSSL Project |
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* for use in the OpenSSL Toolkit. (http://www.openssl.org/)" |
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* |
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* 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to |
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* endorse or promote products derived from this software without |
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* prior written permission. For written permission, please contact |
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* openssl-core@openssl.org. |
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* |
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* 5. Products derived from this software may not be called "OpenSSL" |
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* nor may "OpenSSL" appear in their names without prior written |
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* permission of the OpenSSL Project. |
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* |
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* 6. Redistributions of any form whatsoever must retain the following |
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* acknowledgment: |
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* "This product includes software developed by the OpenSSL Project |
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* for use in the OpenSSL Toolkit (http://www.openssl.org/)" |
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* |
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* THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY |
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* EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
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* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR |
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* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
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* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; |
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* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, |
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* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED |
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* OF THE POSSIBILITY OF SUCH DAMAGE. |
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* ==================================================================== |
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* |
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* This product includes cryptographic software written by Eric Young |
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* (eay@cryptsoft.com). This product includes software written by Tim |
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* Hudson (tjh@cryptsoft.com). |
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* |
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*/ |
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|
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#include <assert.h> |
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#include <limits.h> |
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#include <stdio.h> |
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#include "cryptlib.h" |
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#include "bn_lcl.h" |
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|
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#ifndef OPENSSL_NO_EC2M |
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|
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/* |
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* Maximum number of iterations before BN_GF2m_mod_solve_quad_arr should |
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* fail. |
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*/ |
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# define MAX_ITERATIONS 50 |
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|
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static const BN_ULONG SQR_tb[16] = { 0, 1, 4, 5, 16, 17, 20, 21, |
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64, 65, 68, 69, 80, 81, 84, 85 |
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}; |
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|
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/* Platform-specific macros to accelerate squaring. */ |
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# if defined(SIXTY_FOUR_BIT) || defined(SIXTY_FOUR_BIT_LONG) |
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# define SQR1(w) \ |
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SQR_tb[(w) >> 60 & 0xF] << 56 | SQR_tb[(w) >> 56 & 0xF] << 48 | \ |
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SQR_tb[(w) >> 52 & 0xF] << 40 | SQR_tb[(w) >> 48 & 0xF] << 32 | \ |
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SQR_tb[(w) >> 44 & 0xF] << 24 | SQR_tb[(w) >> 40 & 0xF] << 16 | \ |
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SQR_tb[(w) >> 36 & 0xF] << 8 | SQR_tb[(w) >> 32 & 0xF] |
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# define SQR0(w) \ |
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SQR_tb[(w) >> 28 & 0xF] << 56 | SQR_tb[(w) >> 24 & 0xF] << 48 | \ |
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SQR_tb[(w) >> 20 & 0xF] << 40 | SQR_tb[(w) >> 16 & 0xF] << 32 | \ |
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SQR_tb[(w) >> 12 & 0xF] << 24 | SQR_tb[(w) >> 8 & 0xF] << 16 | \ |
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SQR_tb[(w) >> 4 & 0xF] << 8 | SQR_tb[(w) & 0xF] |
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# endif |
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# ifdef THIRTY_TWO_BIT |
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# define SQR1(w) \ |
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SQR_tb[(w) >> 28 & 0xF] << 24 | SQR_tb[(w) >> 24 & 0xF] << 16 | \ |
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SQR_tb[(w) >> 20 & 0xF] << 8 | SQR_tb[(w) >> 16 & 0xF] |
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# define SQR0(w) \ |
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SQR_tb[(w) >> 12 & 0xF] << 24 | SQR_tb[(w) >> 8 & 0xF] << 16 | \ |
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SQR_tb[(w) >> 4 & 0xF] << 8 | SQR_tb[(w) & 0xF] |
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# endif |
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|
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# if !defined(OPENSSL_BN_ASM_GF2m) |
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/* |
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* Product of two polynomials a, b each with degree < BN_BITS2 - 1, result is |
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* a polynomial r with degree < 2 * BN_BITS - 1 The caller MUST ensure that |
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* the variables have the right amount of space allocated. |
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*/ |
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# ifdef THIRTY_TWO_BIT |
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static void bn_GF2m_mul_1x1(BN_ULONG *r1, BN_ULONG *r0, const BN_ULONG a, |
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const BN_ULONG b) |
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{ |
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register BN_ULONG h, l, s; |
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BN_ULONG tab[8], top2b = a >> 30; |
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register BN_ULONG a1, a2, a4; |
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a1 = a & (0x3FFFFFFF); |
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a2 = a1 << 1; |
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a4 = a2 << 1; |
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tab[0] = 0; |
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tab[1] = a1; |
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tab[2] = a2; |
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tab[3] = a1 ^ a2; |
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tab[4] = a4; |
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tab[5] = a1 ^ a4; |
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tab[6] = a2 ^ a4; |
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tab[7] = a1 ^ a2 ^ a4; |
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s = tab[b & 0x7]; |
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l = s; |
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s = tab[b >> 3 & 0x7]; |
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l ^= s << 3; |
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h = s >> 29; |
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s = tab[b >> 6 & 0x7]; |
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l ^= s << 6; |
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h ^= s >> 26; |
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s = tab[b >> 9 & 0x7]; |
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l ^= s << 9; |
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h ^= s >> 23; |
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s = tab[b >> 12 & 0x7]; |
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l ^= s << 12; |
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h ^= s >> 20; |
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s = tab[b >> 15 & 0x7]; |
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l ^= s << 15; |
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h ^= s >> 17; |
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s = tab[b >> 18 & 0x7]; |
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l ^= s << 18; |
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h ^= s >> 14; |
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s = tab[b >> 21 & 0x7]; |
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l ^= s << 21; |
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h ^= s >> 11; |
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s = tab[b >> 24 & 0x7]; |
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l ^= s << 24; |
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h ^= s >> 8; |
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s = tab[b >> 27 & 0x7]; |
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l ^= s << 27; |
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h ^= s >> 5; |
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s = tab[b >> 30]; |
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l ^= s << 30; |
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h ^= s >> 2; |
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/* compensate for the top two bits of a */ |
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if (top2b & 01) { |
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l ^= b << 30; |
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h ^= b >> 2; |
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} |
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if (top2b & 02) { |
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l ^= b << 31; |
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h ^= b >> 1; |
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} |
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*r1 = h; |
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*r0 = l; |
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} |
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# endif |
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# if defined(SIXTY_FOUR_BIT) || defined(SIXTY_FOUR_BIT_LONG) |
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static void bn_GF2m_mul_1x1(BN_ULONG *r1, BN_ULONG *r0, const BN_ULONG a, |
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const BN_ULONG b) |
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{ |
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register BN_ULONG h, l, s; |
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BN_ULONG tab[16], top3b = a >> 61; |
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register BN_ULONG a1, a2, a4, a8; |
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a1 = a & (0x1FFFFFFFFFFFFFFFULL); |
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a2 = a1 << 1; |
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a4 = a2 << 1; |
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a8 = a4 << 1; |
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tab[0] = 0; |
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tab[1] = a1; |
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tab[2] = a2; |
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tab[3] = a1 ^ a2; |
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tab[4] = a4; |
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tab[5] = a1 ^ a4; |
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tab[6] = a2 ^ a4; |
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tab[7] = a1 ^ a2 ^ a4; |
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tab[8] = a8; |
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tab[9] = a1 ^ a8; |
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tab[10] = a2 ^ a8; |
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tab[11] = a1 ^ a2 ^ a8; |
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tab[12] = a4 ^ a8; |
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tab[13] = a1 ^ a4 ^ a8; |
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tab[14] = a2 ^ a4 ^ a8; |
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tab[15] = a1 ^ a2 ^ a4 ^ a8; |
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s = tab[b & 0xF]; |
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l = s; |
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s = tab[b >> 4 & 0xF]; |
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l ^= s << 4; |
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h = s >> 60; |
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s = tab[b >> 8 & 0xF]; |
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l ^= s << 8; |
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h ^= s >> 56; |
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s = tab[b >> 12 & 0xF]; |
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l ^= s << 12; |
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h ^= s >> 52; |
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s = tab[b >> 16 & 0xF]; |
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l ^= s << 16; |
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h ^= s >> 48; |
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s = tab[b >> 20 & 0xF]; |
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l ^= s << 20; |
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h ^= s >> 44; |
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s = tab[b >> 24 & 0xF]; |
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l ^= s << 24; |
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h ^= s >> 40; |
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s = tab[b >> 28 & 0xF]; |
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l ^= s << 28; |
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h ^= s >> 36; |
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s = tab[b >> 32 & 0xF]; |
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l ^= s << 32; |
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h ^= s >> 32; |
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s = tab[b >> 36 & 0xF]; |
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l ^= s << 36; |
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h ^= s >> 28; |
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s = tab[b >> 40 & 0xF]; |
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l ^= s << 40; |
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h ^= s >> 24; |
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s = tab[b >> 44 & 0xF]; |
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l ^= s << 44; |
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h ^= s >> 20; |
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s = tab[b >> 48 & 0xF]; |
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l ^= s << 48; |
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h ^= s >> 16; |
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s = tab[b >> 52 & 0xF]; |
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l ^= s << 52; |
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h ^= s >> 12; |
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s = tab[b >> 56 & 0xF]; |
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l ^= s << 56; |
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h ^= s >> 8; |
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s = tab[b >> 60]; |
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l ^= s << 60; |
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h ^= s >> 4; |
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|
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/* compensate for the top three bits of a */ |
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if (top3b & 01) { |
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l ^= b << 61; |
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h ^= b >> 3; |
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} |
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if (top3b & 02) { |
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l ^= b << 62; |
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h ^= b >> 2; |
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} |
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if (top3b & 04) { |
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l ^= b << 63; |
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h ^= b >> 1; |
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} |
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*r1 = h; |
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*r0 = l; |
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} |
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# endif |
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|
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/* |
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* Product of two polynomials a, b each with degree < 2 * BN_BITS2 - 1, |
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* result is a polynomial r with degree < 4 * BN_BITS2 - 1 The caller MUST |
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* ensure that the variables have the right amount of space allocated. |
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*/ |
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static void bn_GF2m_mul_2x2(BN_ULONG *r, const BN_ULONG a1, const BN_ULONG a0, |
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const BN_ULONG b1, const BN_ULONG b0) |
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{ |
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BN_ULONG m1, m0; |
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/* r[3] = h1, r[2] = h0; r[1] = l1; r[0] = l0 */ |
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bn_GF2m_mul_1x1(r + 3, r + 2, a1, b1); |
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bn_GF2m_mul_1x1(r + 1, r, a0, b0); |
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bn_GF2m_mul_1x1(&m1, &m0, a0 ^ a1, b0 ^ b1); |
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/* Correction on m1 ^= l1 ^ h1; m0 ^= l0 ^ h0; */ |
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r[2] ^= m1 ^ r[1] ^ r[3]; /* h0 ^= m1 ^ l1 ^ h1; */ |
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r[1] = r[3] ^ r[2] ^ r[0] ^ m1 ^ m0; /* l1 ^= l0 ^ h0 ^ m0; */ |
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} |
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# else |
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void bn_GF2m_mul_2x2(BN_ULONG *r, BN_ULONG a1, BN_ULONG a0, BN_ULONG b1, |
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BN_ULONG b0); |
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# endif |
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|
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/* |
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* Add polynomials a and b and store result in r; r could be a or b, a and b |
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* could be equal; r is the bitwise XOR of a and b. |
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*/ |
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int BN_GF2m_add(BIGNUM *r, const BIGNUM *a, const BIGNUM *b) |
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{ |
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int i; |
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const BIGNUM *at, *bt; |
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|
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bn_check_top(a); |
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bn_check_top(b); |
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|
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if (a->top < b->top) { |
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at = b; |
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bt = a; |
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} else { |
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at = a; |
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bt = b; |
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} |
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|
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if (bn_wexpand(r, at->top) == NULL) |
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return 0; |
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for (i = 0; i < bt->top; i++) { |
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r->d[i] = at->d[i] ^ bt->d[i]; |
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} |
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for (; i < at->top; i++) { |
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r->d[i] = at->d[i]; |
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} |
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r->top = at->top; |
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bn_correct_top(r); |
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return 1; |
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} |
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|
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/*- |
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* Some functions allow for representation of the irreducible polynomials |
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* as an int[], say p. The irreducible f(t) is then of the form: |
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* t^p[0] + t^p[1] + ... + t^p[k] |
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* where m = p[0] > p[1] > ... > p[k] = 0. |
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*/ |
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|
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/* Performs modular reduction of a and store result in r. r could be a. */ |
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int BN_GF2m_mod_arr(BIGNUM *r, const BIGNUM *a, const int p[]) |
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{ |
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int j, k; |
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int n, dN, d0, d1; |
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BN_ULONG zz, *z; |
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|
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bn_check_top(a); |
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|
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if (!p[0]) { |
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/* reduction mod 1 => return 0 */ |
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BN_zero(r); |
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return 1; |
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} |
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|
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/* |
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* Since the algorithm does reduction in the r value, if a != r, copy the |
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* contents of a into r so we can do reduction in r. |
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*/ |
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if (a != r) { |
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if (!bn_wexpand(r, a->top)) |
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return 0; |
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for (j = 0; j < a->top; j++) { |
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r->d[j] = a->d[j]; |
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} |
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r->top = a->top; |
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} |
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z = r->d; |
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|
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/* start reduction */ |
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dN = p[0] / BN_BITS2; |
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for (j = r->top - 1; j > dN;) { |
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zz = z[j]; |
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if (z[j] == 0) { |
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j--; |
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continue; |
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} |
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z[j] = 0; |
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|
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for (k = 1; p[k] != 0; k++) { |
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/* reducing component t^p[k] */ |
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n = p[0] - p[k]; |
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d0 = n % BN_BITS2; |
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d1 = BN_BITS2 - d0; |
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n /= BN_BITS2; |
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z[j - n] ^= (zz >> d0); |
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if (d0) |
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z[j - n - 1] ^= (zz << d1); |
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} |
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|
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/* reducing component t^0 */ |
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n = dN; |
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d0 = p[0] % BN_BITS2; |
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d1 = BN_BITS2 - d0; |
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z[j - n] ^= (zz >> d0); |
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if (d0) |
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z[j - n - 1] ^= (zz << d1); |
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} |
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|
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/* final round of reduction */ |
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while (j == dN) { |
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|
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d0 = p[0] % BN_BITS2; |
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zz = z[dN] >> d0; |
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if (zz == 0) |
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break; |
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d1 = BN_BITS2 - d0; |
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|
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/* clear up the top d1 bits */ |
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if (d0) |
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z[dN] = (z[dN] << d1) >> d1; |
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else |
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z[dN] = 0; |
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z[0] ^= zz; /* reduction t^0 component */ |
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|
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for (k = 1; p[k] != 0; k++) { |
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BN_ULONG tmp_ulong; |
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|
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/* reducing component t^p[k] */ |
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n = p[k] / BN_BITS2; |
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d0 = p[k] % BN_BITS2; |
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d1 = BN_BITS2 - d0; |
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z[n] ^= (zz << d0); |
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tmp_ulong = zz >> d1; |
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if (d0 && tmp_ulong) |
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z[n + 1] ^= tmp_ulong; |
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} |
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|
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} |
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|
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bn_correct_top(r); |
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return 1; |
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} |
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|
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/* |
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* Performs modular reduction of a by p and store result in r. r could be a. |
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* This function calls down to the BN_GF2m_mod_arr implementation; this wrapper |
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* function is only provided for convenience; for best performance, use the |
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* BN_GF2m_mod_arr function. |
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*/ |
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int BN_GF2m_mod(BIGNUM *r, const BIGNUM *a, const BIGNUM *p) |
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{ |
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int ret = 0; |
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int arr[6]; |
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bn_check_top(a); |
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bn_check_top(p); |
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ret = BN_GF2m_poly2arr(p, arr, sizeof(arr) / sizeof(arr[0])); |
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if (!ret || ret > (int)(sizeof(arr) / sizeof(arr[0]))) { |
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BNerr(BN_F_BN_GF2M_MOD, BN_R_INVALID_LENGTH); |
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return 0; |
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} |
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ret = BN_GF2m_mod_arr(r, a, arr); |
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bn_check_top(r); |
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return ret; |
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} |
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|
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/* |
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* Compute the product of two polynomials a and b, reduce modulo p, and store |
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* the result in r. r could be a or b; a could be b. |
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*/ |
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int BN_GF2m_mod_mul_arr(BIGNUM *r, const BIGNUM *a, const BIGNUM *b, |
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const int p[], BN_CTX *ctx) |
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{ |
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int zlen, i, j, k, ret = 0; |
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BIGNUM *s; |
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BN_ULONG x1, x0, y1, y0, zz[4]; |
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|
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bn_check_top(a); |
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bn_check_top(b); |
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|
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if (a == b) { |
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return BN_GF2m_mod_sqr_arr(r, a, p, ctx); |
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} |
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|
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BN_CTX_start(ctx); |
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if ((s = BN_CTX_get(ctx)) == NULL) |
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goto err; |
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|
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zlen = a->top + b->top + 4; |
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if (!bn_wexpand(s, zlen)) |
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goto err; |
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s->top = zlen; |
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|
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for (i = 0; i < zlen; i++) |
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s->d[i] = 0; |
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|
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for (j = 0; j < b->top; j += 2) { |
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y0 = b->d[j]; |
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y1 = ((j + 1) == b->top) ? 0 : b->d[j + 1]; |
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for (i = 0; i < a->top; i += 2) { |
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x0 = a->d[i]; |
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x1 = ((i + 1) == a->top) ? 0 : a->d[i + 1]; |
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bn_GF2m_mul_2x2(zz, x1, x0, y1, y0); |
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for (k = 0; k < 4; k++) |
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s->d[i + j + k] ^= zz[k]; |
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} |
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} |
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|
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bn_correct_top(s); |
|
if (BN_GF2m_mod_arr(r, s, p)) |
|
ret = 1; |
|
bn_check_top(r); |
|
|
|
err: |
|
BN_CTX_end(ctx); |
|
return ret; |
|
} |
|
|
|
/* |
|
* Compute the product of two polynomials a and b, reduce modulo p, and store |
|
* the result in r. r could be a or b; a could equal b. This function calls |
|
* down to the BN_GF2m_mod_mul_arr implementation; this wrapper function is |
|
* only provided for convenience; for best performance, use the |
|
* BN_GF2m_mod_mul_arr function. |
|
*/ |
|
int BN_GF2m_mod_mul(BIGNUM *r, const BIGNUM *a, const BIGNUM *b, |
|
const BIGNUM *p, BN_CTX *ctx) |
|
{ |
|
int ret = 0; |
|
const int max = BN_num_bits(p) + 1; |
|
int *arr = NULL; |
|
bn_check_top(a); |
|
bn_check_top(b); |
|
bn_check_top(p); |
|
if ((arr = (int *)OPENSSL_malloc(sizeof(int) * max)) == NULL) |
|
goto err; |
|
ret = BN_GF2m_poly2arr(p, arr, max); |
|
if (!ret || ret > max) { |
|
BNerr(BN_F_BN_GF2M_MOD_MUL, BN_R_INVALID_LENGTH); |
|
goto err; |
|
} |
|
ret = BN_GF2m_mod_mul_arr(r, a, b, arr, ctx); |
|
bn_check_top(r); |
|
err: |
|
if (arr) |
|
OPENSSL_free(arr); |
|
return ret; |
|
} |
|
|
|
/* Square a, reduce the result mod p, and store it in a. r could be a. */ |
|
int BN_GF2m_mod_sqr_arr(BIGNUM *r, const BIGNUM *a, const int p[], |
|
BN_CTX *ctx) |
|
{ |
|
int i, ret = 0; |
|
BIGNUM *s; |
|
|
|
bn_check_top(a); |
|
BN_CTX_start(ctx); |
|
if ((s = BN_CTX_get(ctx)) == NULL) |
|
goto err; |
|
if (!bn_wexpand(s, 2 * a->top)) |
|
goto err; |
|
|
|
for (i = a->top - 1; i >= 0; i--) { |
|
s->d[2 * i + 1] = SQR1(a->d[i]); |
|
s->d[2 * i] = SQR0(a->d[i]); |
|
} |
|
|
|
s->top = 2 * a->top; |
|
bn_correct_top(s); |
|
if (!BN_GF2m_mod_arr(r, s, p)) |
|
goto err; |
|
bn_check_top(r); |
|
ret = 1; |
|
err: |
|
BN_CTX_end(ctx); |
|
return ret; |
|
} |
|
|
|
/* |
|
* Square a, reduce the result mod p, and store it in a. r could be a. This |
|
* function calls down to the BN_GF2m_mod_sqr_arr implementation; this |
|
* wrapper function is only provided for convenience; for best performance, |
|
* use the BN_GF2m_mod_sqr_arr function. |
|
*/ |
|
int BN_GF2m_mod_sqr(BIGNUM *r, const BIGNUM *a, const BIGNUM *p, BN_CTX *ctx) |
|
{ |
|
int ret = 0; |
|
const int max = BN_num_bits(p) + 1; |
|
int *arr = NULL; |
|
|
|
bn_check_top(a); |
|
bn_check_top(p); |
|
if ((arr = (int *)OPENSSL_malloc(sizeof(int) * max)) == NULL) |
|
goto err; |
|
ret = BN_GF2m_poly2arr(p, arr, max); |
|
if (!ret || ret > max) { |
|
BNerr(BN_F_BN_GF2M_MOD_SQR, BN_R_INVALID_LENGTH); |
|
goto err; |
|
} |
|
ret = BN_GF2m_mod_sqr_arr(r, a, arr, ctx); |
|
bn_check_top(r); |
|
err: |
|
if (arr) |
|
OPENSSL_free(arr); |
|
return ret; |
|
} |
|
|
|
/* |
|
* Invert a, reduce modulo p, and store the result in r. r could be a. Uses |
|
* Modified Almost Inverse Algorithm (Algorithm 10) from Hankerson, D., |
|
* Hernandez, J.L., and Menezes, A. "Software Implementation of Elliptic |
|
* Curve Cryptography Over Binary Fields". |
|
*/ |
|
int BN_GF2m_mod_inv(BIGNUM *r, const BIGNUM *a, const BIGNUM *p, BN_CTX *ctx) |
|
{ |
|
BIGNUM *b, *c = NULL, *u = NULL, *v = NULL, *tmp; |
|
int ret = 0; |
|
|
|
bn_check_top(a); |
|
bn_check_top(p); |
|
|
|
BN_CTX_start(ctx); |
|
|
|
if ((b = BN_CTX_get(ctx)) == NULL) |
|
goto err; |
|
if ((c = BN_CTX_get(ctx)) == NULL) |
|
goto err; |
|
if ((u = BN_CTX_get(ctx)) == NULL) |
|
goto err; |
|
if ((v = BN_CTX_get(ctx)) == NULL) |
|
goto err; |
|
|
|
if (!BN_GF2m_mod(u, a, p)) |
|
goto err; |
|
if (BN_is_zero(u)) |
|
goto err; |
|
|
|
if (!BN_copy(v, p)) |
|
goto err; |
|
# if 0 |
|
if (!BN_one(b)) |
|
goto err; |
|
|
|
while (1) { |
|
while (!BN_is_odd(u)) { |
|
if (BN_is_zero(u)) |
|
goto err; |
|
if (!BN_rshift1(u, u)) |
|
goto err; |
|
if (BN_is_odd(b)) { |
|
if (!BN_GF2m_add(b, b, p)) |
|
goto err; |
|
} |
|
if (!BN_rshift1(b, b)) |
|
goto err; |
|
} |
|
|
|
if (BN_abs_is_word(u, 1)) |
|
break; |
|
|
|
if (BN_num_bits(u) < BN_num_bits(v)) { |
|
tmp = u; |
|
u = v; |
|
v = tmp; |
|
tmp = b; |
|
b = c; |
|
c = tmp; |
|
} |
|
|
|
if (!BN_GF2m_add(u, u, v)) |
|
goto err; |
|
if (!BN_GF2m_add(b, b, c)) |
|
goto err; |
|
} |
|
# else |
|
{ |
|
int i; |
|
int ubits = BN_num_bits(u); |
|
int vbits = BN_num_bits(v); /* v is copy of p */ |
|
int top = p->top; |
|
BN_ULONG *udp, *bdp, *vdp, *cdp; |
|
|
|
if (!bn_wexpand(u, top)) |
|
goto err; |
|
udp = u->d; |
|
for (i = u->top; i < top; i++) |
|
udp[i] = 0; |
|
u->top = top; |
|
if (!bn_wexpand(b, top)) |
|
goto err; |
|
bdp = b->d; |
|
bdp[0] = 1; |
|
for (i = 1; i < top; i++) |
|
bdp[i] = 0; |
|
b->top = top; |
|
if (!bn_wexpand(c, top)) |
|
goto err; |
|
cdp = c->d; |
|
for (i = 0; i < top; i++) |
|
cdp[i] = 0; |
|
c->top = top; |
|
vdp = v->d; /* It pays off to "cache" *->d pointers, |
|
* because it allows optimizer to be more |
|
* aggressive. But we don't have to "cache" |
|
* p->d, because *p is declared 'const'... */ |
|
while (1) { |
|
while (ubits && !(udp[0] & 1)) { |
|
BN_ULONG u0, u1, b0, b1, mask; |
|
|
|
u0 = udp[0]; |
|
b0 = bdp[0]; |
|
mask = (BN_ULONG)0 - (b0 & 1); |
|
b0 ^= p->d[0] & mask; |
|
for (i = 0; i < top - 1; i++) { |
|
u1 = udp[i + 1]; |
|
udp[i] = ((u0 >> 1) | (u1 << (BN_BITS2 - 1))) & BN_MASK2; |
|
u0 = u1; |
|
b1 = bdp[i + 1] ^ (p->d[i + 1] & mask); |
|
bdp[i] = ((b0 >> 1) | (b1 << (BN_BITS2 - 1))) & BN_MASK2; |
|
b0 = b1; |
|
} |
|
udp[i] = u0 >> 1; |
|
bdp[i] = b0 >> 1; |
|
ubits--; |
|
} |
|
|
|
if (ubits <= BN_BITS2) { |
|
if (udp[0] == 0) /* poly was reducible */ |
|
goto err; |
|
if (udp[0] == 1) |
|
break; |
|
} |
|
|
|
if (ubits < vbits) { |
|
i = ubits; |
|
ubits = vbits; |
|
vbits = i; |
|
tmp = u; |
|
u = v; |
|
v = tmp; |
|
tmp = b; |
|
b = c; |
|
c = tmp; |
|
udp = vdp; |
|
vdp = v->d; |
|
bdp = cdp; |
|
cdp = c->d; |
|
} |
|
for (i = 0; i < top; i++) { |
|
udp[i] ^= vdp[i]; |
|
bdp[i] ^= cdp[i]; |
|
} |
|
if (ubits == vbits) { |
|
BN_ULONG ul; |
|
int utop = (ubits - 1) / BN_BITS2; |
|
|
|
while ((ul = udp[utop]) == 0 && utop) |
|
utop--; |
|
ubits = utop * BN_BITS2 + BN_num_bits_word(ul); |
|
} |
|
} |
|
bn_correct_top(b); |
|
} |
|
# endif |
|
|
|
if (!BN_copy(r, b)) |
|
goto err; |
|
bn_check_top(r); |
|
ret = 1; |
|
|
|
err: |
|
# ifdef BN_DEBUG /* BN_CTX_end would complain about the |
|
* expanded form */ |
|
bn_correct_top(c); |
|
bn_correct_top(u); |
|
bn_correct_top(v); |
|
# endif |
|
BN_CTX_end(ctx); |
|
return ret; |
|
} |
|
|
|
/* |
|
* Invert xx, reduce modulo p, and store the result in r. r could be xx. |
|
* This function calls down to the BN_GF2m_mod_inv implementation; this |
|
* wrapper function is only provided for convenience; for best performance, |
|
* use the BN_GF2m_mod_inv function. |
|
*/ |
|
int BN_GF2m_mod_inv_arr(BIGNUM *r, const BIGNUM *xx, const int p[], |
|
BN_CTX *ctx) |
|
{ |
|
BIGNUM *field; |
|
int ret = 0; |
|
|
|
bn_check_top(xx); |
|
BN_CTX_start(ctx); |
|
if ((field = BN_CTX_get(ctx)) == NULL) |
|
goto err; |
|
if (!BN_GF2m_arr2poly(p, field)) |
|
goto err; |
|
|
|
ret = BN_GF2m_mod_inv(r, xx, field, ctx); |
|
bn_check_top(r); |
|
|
|
err: |
|
BN_CTX_end(ctx); |
|
return ret; |
|
} |
|
|
|
# ifndef OPENSSL_SUN_GF2M_DIV |
|
/* |
|
* Divide y by x, reduce modulo p, and store the result in r. r could be x |
|
* or y, x could equal y. |
|
*/ |
|
int BN_GF2m_mod_div(BIGNUM *r, const BIGNUM *y, const BIGNUM *x, |
|
const BIGNUM *p, BN_CTX *ctx) |
|
{ |
|
BIGNUM *xinv = NULL; |
|
int ret = 0; |
|
|
|
bn_check_top(y); |
|
bn_check_top(x); |
|
bn_check_top(p); |
|
|
|
BN_CTX_start(ctx); |
|
xinv = BN_CTX_get(ctx); |
|
if (xinv == NULL) |
|
goto err; |
|
|
|
if (!BN_GF2m_mod_inv(xinv, x, p, ctx)) |
|
goto err; |
|
if (!BN_GF2m_mod_mul(r, y, xinv, p, ctx)) |
|
goto err; |
|
bn_check_top(r); |
|
ret = 1; |
|
|
|
err: |
|
BN_CTX_end(ctx); |
|
return ret; |
|
} |
|
# else |
|
/* |
|
* Divide y by x, reduce modulo p, and store the result in r. r could be x |
|
* or y, x could equal y. Uses algorithm Modular_Division_GF(2^m) from |
|
* Chang-Shantz, S. "From Euclid's GCD to Montgomery Multiplication to the |
|
* Great Divide". |
|
*/ |
|
int BN_GF2m_mod_div(BIGNUM *r, const BIGNUM *y, const BIGNUM *x, |
|
const BIGNUM *p, BN_CTX *ctx) |
|
{ |
|
BIGNUM *a, *b, *u, *v; |
|
int ret = 0; |
|
|
|
bn_check_top(y); |
|
bn_check_top(x); |
|
bn_check_top(p); |
|
|
|
BN_CTX_start(ctx); |
|
|
|
a = BN_CTX_get(ctx); |
|
b = BN_CTX_get(ctx); |
|
u = BN_CTX_get(ctx); |
|
v = BN_CTX_get(ctx); |
|
if (v == NULL) |
|
goto err; |
|
|
|
/* reduce x and y mod p */ |
|
if (!BN_GF2m_mod(u, y, p)) |
|
goto err; |
|
if (!BN_GF2m_mod(a, x, p)) |
|
goto err; |
|
if (!BN_copy(b, p)) |
|
goto err; |
|
|
|
while (!BN_is_odd(a)) { |
|
if (!BN_rshift1(a, a)) |
|
goto err; |
|
if (BN_is_odd(u)) |
|
if (!BN_GF2m_add(u, u, p)) |
|
goto err; |
|
if (!BN_rshift1(u, u)) |
|
goto err; |
|
} |
|
|
|
do { |
|
if (BN_GF2m_cmp(b, a) > 0) { |
|
if (!BN_GF2m_add(b, b, a)) |
|
goto err; |
|
if (!BN_GF2m_add(v, v, u)) |
|
goto err; |
|
do { |
|
if (!BN_rshift1(b, b)) |
|
goto err; |
|
if (BN_is_odd(v)) |
|
if (!BN_GF2m_add(v, v, p)) |
|
goto err; |
|
if (!BN_rshift1(v, v)) |
|
goto err; |
|
} while (!BN_is_odd(b)); |
|
} else if (BN_abs_is_word(a, 1)) |
|
break; |
|
else { |
|
if (!BN_GF2m_add(a, a, b)) |
|
goto err; |
|
if (!BN_GF2m_add(u, u, v)) |
|
goto err; |
|
do { |
|
if (!BN_rshift1(a, a)) |
|
goto err; |
|
if (BN_is_odd(u)) |
|
if (!BN_GF2m_add(u, u, p)) |
|
goto err; |
|
if (!BN_rshift1(u, u)) |
|
goto err; |
|
} while (!BN_is_odd(a)); |
|
} |
|
} while (1); |
|
|
|
if (!BN_copy(r, u)) |
|
goto err; |
|
bn_check_top(r); |
|
ret = 1; |
|
|
|
err: |
|
BN_CTX_end(ctx); |
|
return ret; |
|
} |
|
# endif |
|
|
|
/* |
|
* Divide yy by xx, reduce modulo p, and store the result in r. r could be xx |
|
* * or yy, xx could equal yy. This function calls down to the |
|
* BN_GF2m_mod_div implementation; this wrapper function is only provided for |
|
* convenience; for best performance, use the BN_GF2m_mod_div function. |
|
*/ |
|
int BN_GF2m_mod_div_arr(BIGNUM *r, const BIGNUM *yy, const BIGNUM *xx, |
|
const int p[], BN_CTX *ctx) |
|
{ |
|
BIGNUM *field; |
|
int ret = 0; |
|
|
|
bn_check_top(yy); |
|
bn_check_top(xx); |
|
|
|
BN_CTX_start(ctx); |
|
if ((field = BN_CTX_get(ctx)) == NULL) |
|
goto err; |
|
if (!BN_GF2m_arr2poly(p, field)) |
|
goto err; |
|
|
|
ret = BN_GF2m_mod_div(r, yy, xx, field, ctx); |
|
bn_check_top(r); |
|
|
|
err: |
|
BN_CTX_end(ctx); |
|
return ret; |
|
} |
|
|
|
/* |
|
* Compute the bth power of a, reduce modulo p, and store the result in r. r |
|
* could be a. Uses simple square-and-multiply algorithm A.5.1 from IEEE |
|
* P1363. |
|
*/ |
|
int BN_GF2m_mod_exp_arr(BIGNUM *r, const BIGNUM *a, const BIGNUM *b, |
|
const int p[], BN_CTX *ctx) |
|
{ |
|
int ret = 0, i, n; |
|
BIGNUM *u; |
|
|
|
bn_check_top(a); |
|
bn_check_top(b); |
|
|
|
if (BN_is_zero(b)) |
|
return (BN_one(r)); |
|
|
|
if (BN_abs_is_word(b, 1)) |
|
return (BN_copy(r, a) != NULL); |
|
|
|
BN_CTX_start(ctx); |
|
if ((u = BN_CTX_get(ctx)) == NULL) |
|
goto err; |
|
|
|
if (!BN_GF2m_mod_arr(u, a, p)) |
|
goto err; |
|
|
|
n = BN_num_bits(b) - 1; |
|
for (i = n - 1; i >= 0; i--) { |
|
if (!BN_GF2m_mod_sqr_arr(u, u, p, ctx)) |
|
goto err; |
|
if (BN_is_bit_set(b, i)) { |
|
if (!BN_GF2m_mod_mul_arr(u, u, a, p, ctx)) |
|
goto err; |
|
} |
|
} |
|
if (!BN_copy(r, u)) |
|
goto err; |
|
bn_check_top(r); |
|
ret = 1; |
|
err: |
|
BN_CTX_end(ctx); |
|
return ret; |
|
} |
|
|
|
/* |
|
* Compute the bth power of a, reduce modulo p, and store the result in r. r |
|
* could be a. This function calls down to the BN_GF2m_mod_exp_arr |
|
* implementation; this wrapper function is only provided for convenience; |
|
* for best performance, use the BN_GF2m_mod_exp_arr function. |
|
*/ |
|
int BN_GF2m_mod_exp(BIGNUM *r, const BIGNUM *a, const BIGNUM *b, |
|
const BIGNUM *p, BN_CTX *ctx) |
|
{ |
|
int ret = 0; |
|
const int max = BN_num_bits(p) + 1; |
|
int *arr = NULL; |
|
bn_check_top(a); |
|
bn_check_top(b); |
|
bn_check_top(p); |
|
if ((arr = (int *)OPENSSL_malloc(sizeof(int) * max)) == NULL) |
|
goto err; |
|
ret = BN_GF2m_poly2arr(p, arr, max); |
|
if (!ret || ret > max) { |
|
BNerr(BN_F_BN_GF2M_MOD_EXP, BN_R_INVALID_LENGTH); |
|
goto err; |
|
} |
|
ret = BN_GF2m_mod_exp_arr(r, a, b, arr, ctx); |
|
bn_check_top(r); |
|
err: |
|
if (arr) |
|
OPENSSL_free(arr); |
|
return ret; |
|
} |
|
|
|
/* |
|
* Compute the square root of a, reduce modulo p, and store the result in r. |
|
* r could be a. Uses exponentiation as in algorithm A.4.1 from IEEE P1363. |
|
*/ |
|
int BN_GF2m_mod_sqrt_arr(BIGNUM *r, const BIGNUM *a, const int p[], |
|
BN_CTX *ctx) |
|
{ |
|
int ret = 0; |
|
BIGNUM *u; |
|
|
|
bn_check_top(a); |
|
|
|
if (!p[0]) { |
|
/* reduction mod 1 => return 0 */ |
|
BN_zero(r); |
|
return 1; |
|
} |
|
|
|
BN_CTX_start(ctx); |
|
if ((u = BN_CTX_get(ctx)) == NULL) |
|
goto err; |
|
|
|
if (!BN_set_bit(u, p[0] - 1)) |
|
goto err; |
|
ret = BN_GF2m_mod_exp_arr(r, a, u, p, ctx); |
|
bn_check_top(r); |
|
|
|
err: |
|
BN_CTX_end(ctx); |
|
return ret; |
|
} |
|
|
|
/* |
|
* Compute the square root of a, reduce modulo p, and store the result in r. |
|
* r could be a. This function calls down to the BN_GF2m_mod_sqrt_arr |
|
* implementation; this wrapper function is only provided for convenience; |
|
* for best performance, use the BN_GF2m_mod_sqrt_arr function. |
|
*/ |
|
int BN_GF2m_mod_sqrt(BIGNUM *r, const BIGNUM *a, const BIGNUM *p, BN_CTX *ctx) |
|
{ |
|
int ret = 0; |
|
const int max = BN_num_bits(p) + 1; |
|
int *arr = NULL; |
|
bn_check_top(a); |
|
bn_check_top(p); |
|
if ((arr = (int *)OPENSSL_malloc(sizeof(int) * max)) == NULL) |
|
goto err; |
|
ret = BN_GF2m_poly2arr(p, arr, max); |
|
if (!ret || ret > max) { |
|
BNerr(BN_F_BN_GF2M_MOD_SQRT, BN_R_INVALID_LENGTH); |
|
goto err; |
|
} |
|
ret = BN_GF2m_mod_sqrt_arr(r, a, arr, ctx); |
|
bn_check_top(r); |
|
err: |
|
if (arr) |
|
OPENSSL_free(arr); |
|
return ret; |
|
} |
|
|
|
/* |
|
* Find r such that r^2 + r = a mod p. r could be a. If no r exists returns |
|
* 0. Uses algorithms A.4.7 and A.4.6 from IEEE P1363. |
|
*/ |
|
int BN_GF2m_mod_solve_quad_arr(BIGNUM *r, const BIGNUM *a_, const int p[], |
|
BN_CTX *ctx) |
|
{ |
|
int ret = 0, count = 0, j; |
|
BIGNUM *a, *z, *rho, *w, *w2, *tmp; |
|
|
|
bn_check_top(a_); |
|
|
|
if (!p[0]) { |
|
/* reduction mod 1 => return 0 */ |
|
BN_zero(r); |
|
return 1; |
|
} |
|
|
|
BN_CTX_start(ctx); |
|
a = BN_CTX_get(ctx); |
|
z = BN_CTX_get(ctx); |
|
w = BN_CTX_get(ctx); |
|
if (w == NULL) |
|
goto err; |
|
|
|
if (!BN_GF2m_mod_arr(a, a_, p)) |
|
goto err; |
|
|
|
if (BN_is_zero(a)) { |
|
BN_zero(r); |
|
ret = 1; |
|
goto err; |
|
} |
|
|
|
if (p[0] & 0x1) { /* m is odd */ |
|
/* compute half-trace of a */ |
|
if (!BN_copy(z, a)) |
|
goto err; |
|
for (j = 1; j <= (p[0] - 1) / 2; j++) { |
|
if (!BN_GF2m_mod_sqr_arr(z, z, p, ctx)) |
|
goto err; |
|
if (!BN_GF2m_mod_sqr_arr(z, z, p, ctx)) |
|
goto err; |
|
if (!BN_GF2m_add(z, z, a)) |
|
goto err; |
|
} |
|
|
|
} else { /* m is even */ |
|
|
|
rho = BN_CTX_get(ctx); |
|
w2 = BN_CTX_get(ctx); |
|
tmp = BN_CTX_get(ctx); |
|
if (tmp == NULL) |
|
goto err; |
|
do { |
|
if (!BN_rand(rho, p[0], 0, 0)) |
|
goto err; |
|
if (!BN_GF2m_mod_arr(rho, rho, p)) |
|
goto err; |
|
BN_zero(z); |
|
if (!BN_copy(w, rho)) |
|
goto err; |
|
for (j = 1; j <= p[0] - 1; j++) { |
|
if (!BN_GF2m_mod_sqr_arr(z, z, p, ctx)) |
|
goto err; |
|
if (!BN_GF2m_mod_sqr_arr(w2, w, p, ctx)) |
|
goto err; |
|
if (!BN_GF2m_mod_mul_arr(tmp, w2, a, p, ctx)) |
|
goto err; |
|
if (!BN_GF2m_add(z, z, tmp)) |
|
goto err; |
|
if (!BN_GF2m_add(w, w2, rho)) |
|
goto err; |
|
} |
|
count++; |
|
} while (BN_is_zero(w) && (count < MAX_ITERATIONS)); |
|
if (BN_is_zero(w)) { |
|
BNerr(BN_F_BN_GF2M_MOD_SOLVE_QUAD_ARR, BN_R_TOO_MANY_ITERATIONS); |
|
goto err; |
|
} |
|
} |
|
|
|
if (!BN_GF2m_mod_sqr_arr(w, z, p, ctx)) |
|
goto err; |
|
if (!BN_GF2m_add(w, z, w)) |
|
goto err; |
|
if (BN_GF2m_cmp(w, a)) { |
|
BNerr(BN_F_BN_GF2M_MOD_SOLVE_QUAD_ARR, BN_R_NO_SOLUTION); |
|
goto err; |
|
} |
|
|
|
if (!BN_copy(r, z)) |
|
goto err; |
|
bn_check_top(r); |
|
|
|
ret = 1; |
|
|
|
err: |
|
BN_CTX_end(ctx); |
|
return ret; |
|
} |
|
|
|
/* |
|
* Find r such that r^2 + r = a mod p. r could be a. If no r exists returns |
|
* 0. This function calls down to the BN_GF2m_mod_solve_quad_arr |
|
* implementation; this wrapper function is only provided for convenience; |
|
* for best performance, use the BN_GF2m_mod_solve_quad_arr function. |
|
*/ |
|
int BN_GF2m_mod_solve_quad(BIGNUM *r, const BIGNUM *a, const BIGNUM *p, |
|
BN_CTX *ctx) |
|
{ |
|
int ret = 0; |
|
const int max = BN_num_bits(p) + 1; |
|
int *arr = NULL; |
|
bn_check_top(a); |
|
bn_check_top(p); |
|
if ((arr = (int *)OPENSSL_malloc(sizeof(int) * max)) == NULL) |
|
goto err; |
|
ret = BN_GF2m_poly2arr(p, arr, max); |
|
if (!ret || ret > max) { |
|
BNerr(BN_F_BN_GF2M_MOD_SOLVE_QUAD, BN_R_INVALID_LENGTH); |
|
goto err; |
|
} |
|
ret = BN_GF2m_mod_solve_quad_arr(r, a, arr, ctx); |
|
bn_check_top(r); |
|
err: |
|
if (arr) |
|
OPENSSL_free(arr); |
|
return ret; |
|
} |
|
|
|
/* |
|
* Convert the bit-string representation of a polynomial ( \sum_{i=0}^n a_i * |
|
* x^i) into an array of integers corresponding to the bits with non-zero |
|
* coefficient. Array is terminated with -1. Up to max elements of the array |
|
* will be filled. Return value is total number of array elements that would |
|
* be filled if array was large enough. |
|
*/ |
|
int BN_GF2m_poly2arr(const BIGNUM *a, int p[], int max) |
|
{ |
|
int i, j, k = 0; |
|
BN_ULONG mask; |
|
|
|
if (BN_is_zero(a)) |
|
return 0; |
|
|
|
for (i = a->top - 1; i >= 0; i--) { |
|
if (!a->d[i]) |
|
/* skip word if a->d[i] == 0 */ |
|
continue; |
|
mask = BN_TBIT; |
|
for (j = BN_BITS2 - 1; j >= 0; j--) { |
|
if (a->d[i] & mask) { |
|
if (k < max) |
|
p[k] = BN_BITS2 * i + j; |
|
k++; |
|
} |
|
mask >>= 1; |
|
} |
|
} |
|
|
|
if (k < max) { |
|
p[k] = -1; |
|
k++; |
|
} |
|
|
|
return k; |
|
} |
|
|
|
/* |
|
* Convert the coefficient array representation of a polynomial to a |
|
* bit-string. The array must be terminated by -1. |
|
*/ |
|
int BN_GF2m_arr2poly(const int p[], BIGNUM *a) |
|
{ |
|
int i; |
|
|
|
bn_check_top(a); |
|
BN_zero(a); |
|
for (i = 0; p[i] != -1; i++) { |
|
if (BN_set_bit(a, p[i]) == 0) |
|
return 0; |
|
} |
|
bn_check_top(a); |
|
|
|
return 1; |
|
} |
|
|
|
#endif
|
|
|