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comparison libtommath/bn_s_mp_exptmod.c @ 1436:60fc6476e044

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Update to libtommath v1.0
author Matt Johnston <matt@ucc.asn.au>
date Sat, 24 Jun 2017 22:37:14 +0800
parents 5ff8218bcee9
children 8bba51a55704
comparison
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1435:f849a5ca2efc 1436:60fc6476e044
1 #include <tommath.h> 1 #include <tommath_private.h>
2 #ifdef BN_S_MP_EXPTMOD_C 2 #ifdef BN_S_MP_EXPTMOD_C
3 /* LibTomMath, multiple-precision integer library -- Tom St Denis 3 /* LibTomMath, multiple-precision integer library -- Tom St Denis
4 * 4 *
5 * LibTomMath is a library that provides multiple-precision 5 * LibTomMath is a library that provides multiple-precision
6 * integer arithmetic as well as number theoretic functionality. 6 * integer arithmetic as well as number theoretic functionality.
10 * additional optimizations in place. 10 * additional optimizations in place.
11 * 11 *
12 * The library is free for all purposes without any express 12 * The library is free for all purposes without any express
13 * guarantee it works. 13 * guarantee it works.
14 * 14 *
15 * Tom St Denis, [email protected], http://math.libtomcrypt.com 15 * Tom St Denis, [email protected], http://libtom.org
16 */ 16 */
17 #ifdef MP_LOW_MEM 17 #ifdef MP_LOW_MEM
18 #define TAB_SIZE 32 18 #define TAB_SIZE 32
19 #else 19 #else
20 #define TAB_SIZE 256 20 #define TAB_SIZE 256
162 /* if the bit is zero and mode == 0 then we ignore it 162 /* if the bit is zero and mode == 0 then we ignore it
163 * These represent the leading zero bits before the first 1 bit 163 * These represent the leading zero bits before the first 1 bit
164 * in the exponent. Technically this opt is not required but it 164 * in the exponent. Technically this opt is not required but it
165 * does lower the # of trivial squaring/reductions used 165 * does lower the # of trivial squaring/reductions used
166 */ 166 */
167 if (mode == 0 && y == 0) { 167 if ((mode == 0) && (y == 0)) {
168 continue; 168 continue;
169 } 169 }
170 170
171 /* if the bit is zero and mode == 1 then we square */ 171 /* if the bit is zero and mode == 1 then we square */
172 if (mode == 1 && y == 0) { 172 if ((mode == 1) && (y == 0)) {
173 if ((err = mp_sqr (&res, &res)) != MP_OKAY) { 173 if ((err = mp_sqr (&res, &res)) != MP_OKAY) {
174 goto LBL_RES; 174 goto LBL_RES;
175 } 175 }
176 if ((err = redux (&res, P, &mu)) != MP_OKAY) { 176 if ((err = redux (&res, P, &mu)) != MP_OKAY) {
177 goto LBL_RES; 177 goto LBL_RES;
209 mode = 1; 209 mode = 1;
210 } 210 }
211 } 211 }
212 212
213 /* if bits remain then square/multiply */ 213 /* if bits remain then square/multiply */
214 if (mode == 2 && bitcpy > 0) { 214 if ((mode == 2) && (bitcpy > 0)) {
215 /* square then multiply if the bit is set */ 215 /* square then multiply if the bit is set */
216 for (x = 0; x < bitcpy; x++) { 216 for (x = 0; x < bitcpy; x++) {
217 if ((err = mp_sqr (&res, &res)) != MP_OKAY) { 217 if ((err = mp_sqr (&res, &res)) != MP_OKAY) {
218 goto LBL_RES; 218 goto LBL_RES;
219 } 219 }
245 } 245 }
246 return err; 246 return err;
247 } 247 }
248 #endif 248 #endif
249 249
250 /* $Source: /cvs/libtom/libtommath/bn_s_mp_exptmod.c,v $ */ 250 /* $Source$ */
251 /* $Revision: 1.4 $ */ 251 /* $Revision$ */
252 /* $Date: 2006/03/31 14:18:44 $ */ 252 /* $Date$ */