diff options
Diffstat (limited to 'libtommath/bn_mp_is_square.c')
| -rw-r--r-- | libtommath/bn_mp_is_square.c | 48 |
1 files changed, 17 insertions, 31 deletions
diff --git a/libtommath/bn_mp_is_square.c b/libtommath/bn_mp_is_square.c index b1d2116..69e77a2 100644 --- a/libtommath/bn_mp_is_square.c +++ b/libtommath/bn_mp_is_square.c @@ -1,16 +1,7 @@ #include "tommath_private.h" #ifdef BN_MP_IS_SQUARE_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 */ /* Check if remainders are possible squares - fast exclude non-squares */ static const char rem_128[128] = { @@ -35,9 +26,9 @@ static const char rem_105[105] = { }; /* Store non-zero to ret if arg is square, and zero if not */ -int mp_is_square(const mp_int *arg, int *ret) +mp_err mp_is_square(const mp_int *arg, mp_bool *ret) { - int res; + mp_err err; mp_digit c; mp_int t; unsigned long r; @@ -49,34 +40,33 @@ int mp_is_square(const mp_int *arg, int *ret) return MP_VAL; } - /* digits used? (TSD) */ - if (arg->used == 0) { + if (MP_IS_ZERO(arg)) { return MP_OKAY; } - /* First check mod 128 (suppose that DIGIT_BIT is at least 7) */ - if (rem_128[127u & DIGIT(arg, 0)] == (char)1) { + /* First check mod 128 (suppose that MP_DIGIT_BIT is at least 7) */ + if (rem_128[127u & arg->dp[0]] == (char)1) { return MP_OKAY; } /* Next check mod 105 (3*5*7) */ - if ((res = mp_mod_d(arg, 105uL, &c)) != MP_OKAY) { - return res; + if ((err = mp_mod_d(arg, 105uL, &c)) != MP_OKAY) { + return err; } if (rem_105[c] == (char)1) { return MP_OKAY; } - if ((res = mp_init_set_int(&t, 11L*13L*17L*19L*23L*29L*31L)) != MP_OKAY) { - return res; + if ((err = mp_init_u32(&t, 11u*13u*17u*19u*23u*29u*31u)) != MP_OKAY) { + return err; } - if ((res = mp_mod(arg, &t, &t)) != MP_OKAY) { + if ((err = mp_mod(arg, &t, &t)) != MP_OKAY) { goto LBL_ERR; } - r = mp_get_int(&t); + r = mp_get_u32(&t); /* Check for other prime modules, note it's not an ERROR but we must - * free "t" so the easiest way is to goto LBL_ERR. We know that res + * free "t" so the easiest way is to goto LBL_ERR. We know that err * is already equal to MP_OKAY from the mp_mod call */ if (((1uL<<(r%11uL)) & 0x5C4uL) != 0uL) goto LBL_ERR; @@ -88,20 +78,16 @@ int mp_is_square(const mp_int *arg, int *ret) if (((1uL<<(r%31uL)) & 0x6DE2B848uL) != 0uL) goto LBL_ERR; /* Final check - is sqr(sqrt(arg)) == arg ? */ - if ((res = mp_sqrt(arg, &t)) != MP_OKAY) { + if ((err = mp_sqrt(arg, &t)) != MP_OKAY) { goto LBL_ERR; } - if ((res = mp_sqr(&t, &t)) != MP_OKAY) { + if ((err = mp_sqr(&t, &t)) != MP_OKAY) { goto LBL_ERR; } *ret = (mp_cmp_mag(&t, arg) == MP_EQ) ? MP_YES : MP_NO; LBL_ERR: mp_clear(&t); - return res; + return err; } #endif - -/* ref: HEAD -> master, tag: v1.1.0 */ -/* git commit: 08549ad6bc8b0cede0b357a9c341c5c6473a9c55 */ -/* commit time: 2019-01-28 20:32:32 +0100 */ |