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comparison libtommath/bn_mp_get_int.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
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1435:f849a5ca2efc 1436:60fc6476e044
1 #include <tommath.h> 1 #include <tommath_private.h>
2 #ifdef BN_MP_GET_INT_C 2 #ifdef BN_MP_GET_INT_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 17
18 /* get the lower 32-bits of an mp_int */ 18 /* get the lower 32-bits of an mp_int */
19 unsigned long mp_get_int(mp_int * a) 19 unsigned long mp_get_int(mp_int * a)
20 { 20 {
21 int i; 21 int i;
22 unsigned long res; 22 mp_min_u32 res;
23 23
24 if (a->used == 0) { 24 if (a->used == 0) {
25 return 0; 25 return 0;
26 } 26 }
27 27
28 /* get number of digits of the lsb we have to read */ 28 /* get number of digits of the lsb we have to read */
29 i = MIN(a->used,(int)((sizeof(unsigned long)*CHAR_BIT+DIGIT_BIT-1)/DIGIT_BIT))-1; 29 i = MIN(a->used,(int)(((sizeof(unsigned long) * CHAR_BIT) + DIGIT_BIT - 1) / DIGIT_BIT)) - 1;
30 30
31 /* get most significant digit of result */ 31 /* get most significant digit of result */
32 res = DIGIT(a,i); 32 res = DIGIT(a,i);
33 33
34 while (--i >= 0) { 34 while (--i >= 0) {
35 res = (res << DIGIT_BIT) | DIGIT(a,i); 35 res = (res << DIGIT_BIT) | DIGIT(a,i);
36 } 36 }
37 37
38 /* force result to 32-bits always so it is consistent on non 32-bit platforms */ 38 /* force result to 32-bits always so it is consistent on non 32-bit platforms */
39 return res & 0xFFFFFFFFUL; 39 return res & 0xFFFFFFFFUL;
40 } 40 }
41 #endif 41 #endif
42 42
43 /* $Source: /cvs/libtom/libtommath/bn_mp_get_int.c,v $ */ 43 /* $Source$ */
44 /* $Revision: 1.3 $ */ 44 /* $Revision$ */
45 /* $Date: 2006/03/31 14:18:44 $ */ 45 /* $Date$ */