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hcrypto: import libtommath v1.2.0

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This commit is contained in:
Luke Howard
2020-04-12 18:37:13 +10:00
parent 7181c109d0
commit c403b66082
287 changed files with 28273 additions and 38374 deletions
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112
lib/hcrypto/libtommath/bn_mp_sqrt.c
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@@ -1,81 +1,67 @@
#include <tommath.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, tomstdenis@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
/* $Source: /cvs/libtom/libtommath/bn_mp_sqrt.c,v $ */
/* $Revision: 1.4 $ */
/* $Date: 2006/12/28 01:25:13 $ */