diff options
Diffstat (limited to 'libtommath/bn_mp_reduce_2k_l.c')
| -rw-r--r-- | libtommath/bn_mp_reduce_2k_l.c | 32 |
1 files changed, 19 insertions, 13 deletions
diff --git a/libtommath/bn_mp_reduce_2k_l.c b/libtommath/bn_mp_reduce_2k_l.c index 8e52efa..3b23a37 100644 --- a/libtommath/bn_mp_reduce_2k_l.c +++ b/libtommath/bn_mp_reduce_2k_l.c @@ -1,4 +1,4 @@ -#include <tommath.h> +#include <tommath_private.h> #ifdef BN_MP_REDUCE_2K_L_C /* LibTomMath, multiple-precision integer library -- Tom St Denis * @@ -12,47 +12,53 @@ * The library is free for all purposes without any express * guarantee it works. * - * Tom St Denis, tomstdenis@gmail.com, http://math.libtomcrypt.com + * Tom St Denis, tstdenis82@gmail.com, http://libtom.org */ -/* reduces a modulo n where n is of the form 2**p - d +/* reduces a modulo n where n is of the form 2**p - d This differs from reduce_2k since "d" can be larger than a single digit. */ -int mp_reduce_2k_l(mp_int *a, mp_int *n, mp_int *d) +int mp_reduce_2k_l(mp_int *a, const mp_int *n, mp_int *d) { mp_int q; int p, res; - + if ((res = mp_init(&q)) != MP_OKAY) { return res; } - - p = mp_count_bits(n); + + p = mp_count_bits(n); top: /* q = a/2**p, a = a mod 2**p */ if ((res = mp_div_2d(a, p, &q, a)) != MP_OKAY) { goto ERR; } - + /* q = q * d */ - if ((res = mp_mul(&q, d, &q)) != MP_OKAY) { + if ((res = mp_mul(&q, d, &q)) != MP_OKAY) { goto ERR; } - + /* a = a + q */ if ((res = s_mp_add(a, &q, a)) != MP_OKAY) { goto ERR; } - + if (mp_cmp_mag(a, n) != MP_LT) { - s_mp_sub(a, n, a); + if ((res = s_mp_sub(a, n, a)) != MP_OKAY) { + goto ERR; + } goto top; } - + ERR: mp_clear(&q); return res; } #endif + +/* ref: $Format:%D$ */ +/* git commit: $Format:%H$ */ +/* commit time: $Format:%ai$ */ |