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authorSteffen Jaeckel <s_jaeckel@gmx.de>2019-09-16 15:50:38 +0200
committerMatt Johnston <matt@ucc.asn.au>2019-09-16 21:50:38 +0800
commit615ed4e46a52b6bfe0bfc581b8c2fbcc6cc488d1 (patch)
tree12b2ba29ae4c42fc65d64d43968c5d03ab3f4452 /libtommath/bn_mp_reduce.c
parentfa116e983b4931010e1082dd5c8bf38bbc77718c (diff)
update ltm to 1.1.0 and enable FIPS 186.4 compliant key-generation (#79)
* make key-generation compliant to FIPS 186.4 * fix includes in tommath_class.h * update fuzzcorpus instead of error-out * fixup fuzzing make-targets * update Makefile.in * apply necessary patches to ltm sources * clean-up not required ltm files * update to vanilla ltm 1.1.0 this already only contains the required files * remove set/get double
Diffstat (limited to 'libtommath/bn_mp_reduce.c')
-rw-r--r--libtommath/bn_mp_reduce.c125
1 files changed, 61 insertions, 64 deletions
diff --git a/libtommath/bn_mp_reduce.c b/libtommath/bn_mp_reduce.c
index 367383f..9cb9d2a 100644
--- a/libtommath/bn_mp_reduce.c
+++ b/libtommath/bn_mp_reduce.c
@@ -1,4 +1,4 @@
-#include <tommath_private.h>
+#include "tommath_private.h"
#ifdef BN_MP_REDUCE_C
/* LibTomMath, multiple-precision integer library -- Tom St Denis
*
@@ -9,92 +9,89 @@
* 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, tstdenis82@gmail.com, http://libtom.org
+ * SPDX-License-Identifier: Unlicense
*/
/* reduces x mod m, assumes 0 < x < m**2, mu is
* precomputed via mp_reduce_setup.
* From HAC pp.604 Algorithm 14.42
*/
-int mp_reduce (mp_int * x, mp_int * m, mp_int * mu)
+int mp_reduce(mp_int *x, const mp_int *m, const mp_int *mu)
{
- mp_int q;
- int res, um = m->used;
+ mp_int q;
+ int res, um = m->used;
- /* q = x */
- if ((res = mp_init_copy (&q, x)) != MP_OKAY) {
- return res;
- }
+ /* q = x */
+ if ((res = mp_init_copy(&q, x)) != MP_OKAY) {
+ return res;
+ }
- /* q1 = x / b**(k-1) */
- mp_rshd (&q, um - 1);
+ /* q1 = x / b**(k-1) */
+ mp_rshd(&q, um - 1);
- /* according to HAC this optimization is ok */
- if (((mp_digit) um) > (((mp_digit)1) << (DIGIT_BIT - 1))) {
- if ((res = mp_mul (&q, mu, &q)) != MP_OKAY) {
- goto CLEANUP;
- }
- } else {
+ /* according to HAC this optimization is ok */
+ if ((mp_digit)um > ((mp_digit)1 << (DIGIT_BIT - 1))) {
+ if ((res = mp_mul(&q, mu, &q)) != MP_OKAY) {
+ goto CLEANUP;
+ }
+ } else {
#ifdef BN_S_MP_MUL_HIGH_DIGS_C
- if ((res = s_mp_mul_high_digs (&q, mu, &q, um)) != MP_OKAY) {
- goto CLEANUP;
- }
+ if ((res = s_mp_mul_high_digs(&q, mu, &q, um)) != MP_OKAY) {
+ goto CLEANUP;
+ }
#elif defined(BN_FAST_S_MP_MUL_HIGH_DIGS_C)
- if ((res = fast_s_mp_mul_high_digs (&q, mu, &q, um)) != MP_OKAY) {
- goto CLEANUP;
- }
+ if ((res = fast_s_mp_mul_high_digs(&q, mu, &q, um)) != MP_OKAY) {
+ goto CLEANUP;
+ }
#else
- {
- res = MP_VAL;
- goto CLEANUP;
- }
+ {
+ res = MP_VAL;
+ goto CLEANUP;
+ }
#endif
- }
-
- /* q3 = q2 / b**(k+1) */
- mp_rshd (&q, um + 1);
+ }
- /* x = x mod b**(k+1), quick (no division) */
- if ((res = mp_mod_2d (x, DIGIT_BIT * (um + 1), x)) != MP_OKAY) {
- goto CLEANUP;
- }
+ /* q3 = q2 / b**(k+1) */
+ mp_rshd(&q, um + 1);
- /* q = q * m mod b**(k+1), quick (no division) */
- if ((res = s_mp_mul_digs (&q, m, &q, um + 1)) != MP_OKAY) {
- goto CLEANUP;
- }
-
- /* x = x - q */
- if ((res = mp_sub (x, &q, x)) != MP_OKAY) {
- goto CLEANUP;
- }
-
- /* If x < 0, add b**(k+1) to it */
- if (mp_cmp_d (x, 0) == MP_LT) {
- mp_set (&q, 1);
- if ((res = mp_lshd (&q, um + 1)) != MP_OKAY)
+ /* x = x mod b**(k+1), quick (no division) */
+ if ((res = mp_mod_2d(x, DIGIT_BIT * (um + 1), x)) != MP_OKAY) {
goto CLEANUP;
- if ((res = mp_add (x, &q, x)) != MP_OKAY)
+ }
+
+ /* q = q * m mod b**(k+1), quick (no division) */
+ if ((res = s_mp_mul_digs(&q, m, &q, um + 1)) != MP_OKAY) {
goto CLEANUP;
- }
+ }
- /* Back off if it's too big */
- while (mp_cmp (x, m) != MP_LT) {
- if ((res = s_mp_sub (x, m, x)) != MP_OKAY) {
+ /* x = x - q */
+ if ((res = mp_sub(x, &q, x)) != MP_OKAY) {
goto CLEANUP;
- }
- }
+ }
+
+ /* If x < 0, add b**(k+1) to it */
+ if (mp_cmp_d(x, 0uL) == MP_LT) {
+ mp_set(&q, 1uL);
+ if ((res = mp_lshd(&q, um + 1)) != MP_OKAY)
+ goto CLEANUP;
+ if ((res = mp_add(x, &q, x)) != MP_OKAY)
+ goto CLEANUP;
+ }
+
+ /* Back off if it's too big */
+ while (mp_cmp(x, m) != MP_LT) {
+ if ((res = s_mp_sub(x, m, x)) != MP_OKAY) {
+ goto CLEANUP;
+ }
+ }
CLEANUP:
- mp_clear (&q);
+ mp_clear(&q);
- return res;
+ return res;
}
#endif
-/* ref: $Format:%D$ */
-/* git commit: $Format:%H$ */
-/* commit time: $Format:%ai$ */
+/* ref: HEAD -> master, tag: v1.1.0 */
+/* git commit: 08549ad6bc8b0cede0b357a9c341c5c6473a9c55 */
+/* commit time: 2019-01-28 20:32:32 +0100 */