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-rw-r--r--libtommath/bn_mp_sqrt.c112
1 files changed, 49 insertions, 63 deletions
diff --git a/libtommath/bn_mp_sqrt.c b/libtommath/bn_mp_sqrt.c
index d3b5d62..82d6824 100644
--- a/libtommath/bn_mp_sqrt.c
+++ b/libtommath/bn_mp_sqrt.c
@@ -1,81 +1,67 @@
-#include <tommath_private.h>
+#include "tommath_private.h"
#ifdef BN_MP_SQRT_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, tstdenis82@gmail.com, http://libtom.org
- */
+/* LibTomMath, multiple-precision integer library -- Tom St Denis */
+/* SPDX-License-Identifier: Unlicense */
/* this function is less generic than mp_n_root, simpler and faster */
-int mp_sqrt(mp_int *arg, mp_int *ret)
+mp_err mp_sqrt(const mp_int *arg, mp_int *ret)
{
- int res;
- mp_int t1,t2;
+ mp_err err;
+ mp_int t1, t2;
- /* must be positive */
- if (arg->sign == MP_NEG) {
- return MP_VAL;
- }
+ /* must be positive */
+ if (arg->sign == MP_NEG) {
+ return MP_VAL;
+ }
- /* easy out */
- if (mp_iszero(arg) == MP_YES) {
- mp_zero(ret);
- return MP_OKAY;
- }
+ /* easy out */
+ if (MP_IS_ZERO(arg)) {
+ mp_zero(ret);
+ return MP_OKAY;
+ }
- if ((res = mp_init_copy(&t1, arg)) != MP_OKAY) {
- return res;
- }
+ if ((err = mp_init_copy(&t1, arg)) != MP_OKAY) {
+ return err;
+ }
- if ((res = mp_init(&t2)) != MP_OKAY) {
- goto E2;
- }
+ if ((err = mp_init(&t2)) != MP_OKAY) {
+ goto E2;
+ }
- /* First approx. (not very bad for large arg) */
- mp_rshd (&t1,t1.used/2);
+ /* First approx. (not very bad for large arg) */
+ mp_rshd(&t1, t1.used/2);
- /* t1 > 0 */
- if ((res = mp_div(arg,&t1,&t2,NULL)) != MP_OKAY) {
- goto E1;
- }
- if ((res = mp_add(&t1,&t2,&t1)) != MP_OKAY) {
- goto E1;
- }
- if ((res = mp_div_2(&t1,&t1)) != MP_OKAY) {
- goto E1;
- }
- /* And now t1 > sqrt(arg) */
- do {
- if ((res = mp_div(arg,&t1,&t2,NULL)) != MP_OKAY) {
+ /* t1 > 0 */
+ if ((err = mp_div(arg, &t1, &t2, NULL)) != MP_OKAY) {
goto E1;
- }
- if ((res = mp_add(&t1,&t2,&t1)) != MP_OKAY) {
+ }
+ if ((err = mp_add(&t1, &t2, &t1)) != MP_OKAY) {
goto E1;
- }
- if ((res = mp_div_2(&t1,&t1)) != MP_OKAY) {
+ }
+ if ((err = mp_div_2(&t1, &t1)) != MP_OKAY) {
goto E1;
- }
- /* t1 >= sqrt(arg) >= t2 at this point */
- } while (mp_cmp_mag(&t1,&t2) == MP_GT);
+ }
+ /* And now t1 > sqrt(arg) */
+ do {
+ if ((err = mp_div(arg, &t1, &t2, NULL)) != MP_OKAY) {
+ goto E1;
+ }
+ if ((err = mp_add(&t1, &t2, &t1)) != MP_OKAY) {
+ goto E1;
+ }
+ if ((err = mp_div_2(&t1, &t1)) != MP_OKAY) {
+ goto E1;
+ }
+ /* t1 >= sqrt(arg) >= t2 at this point */
+ } while (mp_cmp_mag(&t1, &t2) == MP_GT);
- mp_exch(&t1,ret);
+ mp_exch(&t1, ret);
-E1: mp_clear(&t2);
-E2: mp_clear(&t1);
- return res;
+E1:
+ mp_clear(&t2);
+E2:
+ mp_clear(&t1);
+ return err;
}
#endif
-
-/* ref: $Format:%D$ */
-/* git commit: $Format:%H$ */
-/* commit time: $Format:%ai$ */