diff options
Diffstat (limited to 'libtommath/bn_mp_reduce_2k.c')
| -rw-r--r-- | libtommath/bn_mp_reduce_2k.c | 28 |
1 files changed, 17 insertions, 11 deletions
diff --git a/libtommath/bn_mp_reduce_2k.c b/libtommath/bn_mp_reduce_2k.c index 428f2ff..2876a75 100644 --- a/libtommath/bn_mp_reduce_2k.c +++ b/libtommath/bn_mp_reduce_2k.c @@ -1,4 +1,4 @@ -#include <tommath.h> +#include <tommath_private.h> #ifdef BN_MP_REDUCE_2K_C /* LibTomMath, multiple-precision integer library -- Tom St Denis * @@ -12,7 +12,7 @@ * 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 */ @@ -20,38 +20,44 @@ int mp_reduce_2k(mp_int *a, mp_int *n, mp_digit 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; } - + if (d != 1) { /* q = q * d */ - if ((res = mp_mul_d(&q, d, &q)) != MP_OKAY) { + if ((res = mp_mul_d(&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 + +/* $Source$ */ +/* $Revision$ */ +/* $Date$ */ |