diff options
Diffstat (limited to 'libtommath/bn_mp_sqrt.c')
| -rw-r--r-- | libtommath/bn_mp_sqrt.c | 103 |
1 files changed, 51 insertions, 52 deletions
diff --git a/libtommath/bn_mp_sqrt.c b/libtommath/bn_mp_sqrt.c index d3b5d62..77a01a0 100644 --- a/libtommath/bn_mp_sqrt.c +++ b/libtommath/bn_mp_sqrt.c @@ -1,4 +1,4 @@ -#include <tommath_private.h> +#include "tommath_private.h" #ifdef BN_MP_SQRT_C /* LibTomMath, multiple-precision integer library -- Tom St Denis * @@ -9,73 +9,72 @@ * 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 */ /* this function is less generic than mp_n_root, simpler and faster */ -int mp_sqrt(mp_int *arg, mp_int *ret) +int mp_sqrt(const mp_int *arg, mp_int *ret) { - int res; - mp_int t1,t2; + int res; + 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_iszero(arg) == MP_YES) { + mp_zero(ret); + return MP_OKAY; + } - if ((res = mp_init_copy(&t1, arg)) != MP_OKAY) { - return res; - } + if ((res = mp_init_copy(&t1, arg)) != MP_OKAY) { + return res; + } - if ((res = mp_init(&t2)) != MP_OKAY) { - goto E2; - } + if ((res = 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 ((res = mp_div(arg, &t1, &t2, NULL)) != MP_OKAY) { goto E1; - } - if ((res = mp_add(&t1,&t2,&t1)) != MP_OKAY) { + } + if ((res = mp_add(&t1, &t2, &t1)) != MP_OKAY) { goto E1; - } - if ((res = mp_div_2(&t1,&t1)) != MP_OKAY) { + } + if ((res = 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 ((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; + } + /* 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 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 */ |