1 #include <tommath.h> 2 #ifdef BN_MP_REDUCE_2K_SETUP_L_C 3 /* LibTomMath, multiple-precision integer library -- Tom St Denis 4 * 5 * LibTomMath is a library that provides multiple-precision 6 * integer arithmetic as well as number theoretic functionality. 7 * 8 * The library was designed directly after the MPI library by 9 * Michael Fromberger but has been written from scratch with 10 * additional optimizations in place. 11 * 12 * The library is free for all purposes without any express 13 * guarantee it works. 14 * 15 * Tom St Denis, tomstdenis (at) gmail.com, http://math.libtomcrypt.com 16 */ 17 18 /* determines the setup value */ 19 int mp_reduce_2k_setup_l(mp_int *a, mp_int *d) 20 { 21 int res; 22 mp_int tmp; 23 24 if ((res = mp_init(&tmp)) != MP_OKAY) { 25 return res; 26 } 27 28 if ((res = mp_2expt(&tmp, mp_count_bits(a))) != MP_OKAY) { 29 goto ERR; 30 } 31 32 if ((res = s_mp_sub(&tmp, a, d)) != MP_OKAY) { 33 goto ERR; 34 } 35 36 ERR: 37 mp_clear(&tmp); 38 return res; 39 } 40 #endif 41 42 /* $Source: /cvs/libtom/libtommath/bn_mp_reduce_2k_setup_l.c,v $ */ 43 /* $Revision: 1.3 $ */ 44 /* $Date: 2006/03/31 14:18:44 $ */ 45
