summaryrefslogtreecommitdiffstats
path: root/libtommath/bn_mp_montgomery_calc_normalization.c
diff options
context:
space:
mode:
Diffstat (limited to 'libtommath/bn_mp_montgomery_calc_normalization.c')
-rw-r--r--libtommath/bn_mp_montgomery_calc_normalization.c38
1 files changed, 13 insertions, 25 deletions
diff --git a/libtommath/bn_mp_montgomery_calc_normalization.c b/libtommath/bn_mp_montgomery_calc_normalization.c
index 848378c..8379789 100644
--- a/libtommath/bn_mp_montgomery_calc_normalization.c
+++ b/libtommath/bn_mp_montgomery_calc_normalization.c
@@ -1,16 +1,7 @@
#include "tommath_private.h"
#ifdef BN_MP_MONTGOMERY_CALC_NORMALIZATION_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.
- *
- * SPDX-License-Identifier: Unlicense
- */
+/* LibTomMath, multiple-precision integer library -- Tom St Denis */
+/* SPDX-License-Identifier: Unlicense */
/*
* shifts with subtractions when the result is greater than b.
@@ -18,16 +9,17 @@
* The method is slightly modified to shift B unconditionally upto just under
* the leading bit of b. This saves alot of multiple precision shifting.
*/
-int mp_montgomery_calc_normalization(mp_int *a, const mp_int *b)
+mp_err mp_montgomery_calc_normalization(mp_int *a, const mp_int *b)
{
- int x, bits, res;
+ int x, bits;
+ mp_err err;
/* how many bits of last digit does b use */
- bits = mp_count_bits(b) % DIGIT_BIT;
+ bits = mp_count_bits(b) % MP_DIGIT_BIT;
if (b->used > 1) {
- if ((res = mp_2expt(a, ((b->used - 1) * DIGIT_BIT) + bits - 1)) != MP_OKAY) {
- return res;
+ if ((err = mp_2expt(a, ((b->used - 1) * MP_DIGIT_BIT) + bits - 1)) != MP_OKAY) {
+ return err;
}
} else {
mp_set(a, 1uL);
@@ -36,13 +28,13 @@ int mp_montgomery_calc_normalization(mp_int *a, const mp_int *b)
/* now compute C = A * B mod b */
- for (x = bits - 1; x < (int)DIGIT_BIT; x++) {
- if ((res = mp_mul_2(a, a)) != MP_OKAY) {
- return res;
+ for (x = bits - 1; x < (int)MP_DIGIT_BIT; x++) {
+ if ((err = mp_mul_2(a, a)) != MP_OKAY) {
+ return err;
}
if (mp_cmp_mag(a, b) != MP_LT) {
- if ((res = s_mp_sub(a, b, a)) != MP_OKAY) {
- return res;
+ if ((err = s_mp_sub(a, b, a)) != MP_OKAY) {
+ return err;
}
}
}
@@ -50,7 +42,3 @@ int mp_montgomery_calc_normalization(mp_int *a, const mp_int *b)
return MP_OKAY;
}
#endif
-
-/* ref: $Format:%D$ */
-/* git commit: $Format:%H$ */
-/* commit time: $Format:%ai$ */