-#include <tommath.h>
+#include "tommath_private.h"
#ifdef BN_MP_REDUCE_2K_C
-/* LibTomMath, multiple-precision integer library -- Tom St Denis
- *
- * LibTomMath is a library that provides multiple-precision
- * integer arithmetic as well as number theoretic functionality.
- *
- * The library was designed directly after the MPI library by
- * Michael Fromberger but has been written from scratch with
- * additional optimizations in place.
- *
- * The library is free for all purposes without any express
- * guarantee it works.
- *
- * Tom St Denis, tomstdenis@gmail.com, http://libtom.org
- */
+/* LibTomMath, multiple-precision integer library -- Tom St Denis */
+/* SPDX-License-Identifier: Unlicense */
/* reduces a modulo n where n is of the form 2**p - d */
-int mp_reduce_2k(mp_int *a, mp_int *n, mp_digit d)
+mp_err mp_reduce_2k(mp_int *a, const mp_int *n, mp_digit d)
{
mp_int q;
- int p, res;
+ mp_err err;
+ int p;
- if ((res = mp_init(&q)) != MP_OKAY) {
- return res;
+ if ((err = mp_init(&q)) != MP_OKAY) {
+ return err;
}
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 ((err = mp_div_2d(a, p, &q, a)) != MP_OKAY) {
+ goto LBL_ERR;
}
- if (d != 1) {
+ if (d != 1u) {
/* q = q * d */
- if ((res = mp_mul_d(&q, d, &q)) != MP_OKAY) {
- goto ERR;
+ if ((err = mp_mul_d(&q, d, &q)) != MP_OKAY) {
+ goto LBL_ERR;
}
}
/* a = a + q */
- if ((res = s_mp_add(a, &q, a)) != MP_OKAY) {
- goto ERR;
+ if ((err = s_mp_add(a, &q, a)) != MP_OKAY) {
+ goto LBL_ERR;
}
if (mp_cmp_mag(a, n) != MP_LT) {
- s_mp_sub(a, n, a);
+ if ((err = s_mp_sub(a, n, a)) != MP_OKAY) {
+ goto LBL_ERR;
+ }
goto top;
}
-ERR:
+LBL_ERR:
mp_clear(&q);
- return res;
+ return err;
}
#endif
-
-/* $Source: /cvs/libtom/libtommath/bn_mp_reduce_2k.c,v $ */
-/* $Revision: 1.4 $ */
-/* $Date: 2006/12/28 01:25:13 $ */