Mercurial > dropbear
diff libtommath/bn_mp_sqrtmod_prime.c @ 1692:1051e4eea25a
Update LibTomMath to 1.2.0 (#84)
* update C files
* update other files
* update headers
* update makefiles
* remove mp_set/get_double()
* use ltm 1.2.0 API
* update ltm_desc
* use bundled tommath if system-tommath is too old
* XMALLOC etc. were changed to MP_MALLOC etc.
| author | Steffen Jaeckel <s@jaeckel.eu> |
|---|---|
| date | Tue, 26 May 2020 17:36:47 +0200 |
| parents | f52919ffd3b1 |
| children |
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--- a/libtommath/bn_mp_sqrtmod_prime.c Tue May 26 23:27:26 2020 +0800 +++ b/libtommath/bn_mp_sqrtmod_prime.c Tue May 26 17:36:47 2020 +0200 @@ -1,16 +1,7 @@ #include "tommath_private.h" #ifdef BN_MP_SQRTMOD_PRIME_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 */ /* Tonelli-Shanks algorithm * https://en.wikipedia.org/wiki/Tonelli%E2%80%93Shanks_algorithm @@ -18,9 +9,10 @@ * */ -int mp_sqrtmod_prime(const mp_int *n, const mp_int *prime, mp_int *ret) +mp_err mp_sqrtmod_prime(const mp_int *n, const mp_int *prime, mp_int *ret) { - int res, legendre; + mp_err err; + int legendre; mp_int t1, C, Q, S, Z, M, T, R, two; mp_digit i; @@ -30,90 +22,89 @@ return MP_OKAY; } if (mp_cmp_d(prime, 2uL) == MP_EQ) return MP_VAL; /* prime must be odd */ - if ((res = mp_jacobi(n, prime, &legendre)) != MP_OKAY) return res; + if ((err = mp_kronecker(n, prime, &legendre)) != MP_OKAY) return err; if (legendre == -1) return MP_VAL; /* quadratic non-residue mod prime */ - if ((res = mp_init_multi(&t1, &C, &Q, &S, &Z, &M, &T, &R, &two, NULL)) != MP_OKAY) { - return res; + if ((err = mp_init_multi(&t1, &C, &Q, &S, &Z, &M, &T, &R, &two, NULL)) != MP_OKAY) { + return err; } /* SPECIAL CASE: if prime mod 4 == 3 - * compute directly: res = n^(prime+1)/4 mod prime + * compute directly: err = n^(prime+1)/4 mod prime * Handbook of Applied Cryptography algorithm 3.36 */ - if ((res = mp_mod_d(prime, 4uL, &i)) != MP_OKAY) goto cleanup; + if ((err = mp_mod_d(prime, 4uL, &i)) != MP_OKAY) goto cleanup; if (i == 3u) { - if ((res = mp_add_d(prime, 1uL, &t1)) != MP_OKAY) goto cleanup; - if ((res = mp_div_2(&t1, &t1)) != MP_OKAY) goto cleanup; - if ((res = mp_div_2(&t1, &t1)) != MP_OKAY) goto cleanup; - if ((res = mp_exptmod(n, &t1, prime, ret)) != MP_OKAY) goto cleanup; - res = MP_OKAY; + if ((err = mp_add_d(prime, 1uL, &t1)) != MP_OKAY) goto cleanup; + if ((err = mp_div_2(&t1, &t1)) != MP_OKAY) goto cleanup; + if ((err = mp_div_2(&t1, &t1)) != MP_OKAY) goto cleanup; + if ((err = mp_exptmod(n, &t1, prime, ret)) != MP_OKAY) goto cleanup; + err = MP_OKAY; goto cleanup; } /* NOW: Tonelli-Shanks algorithm */ /* factor out powers of 2 from prime-1, defining Q and S as: prime-1 = Q*2^S */ - if ((res = mp_copy(prime, &Q)) != MP_OKAY) goto cleanup; - if ((res = mp_sub_d(&Q, 1uL, &Q)) != MP_OKAY) goto cleanup; + if ((err = mp_copy(prime, &Q)) != MP_OKAY) goto cleanup; + if ((err = mp_sub_d(&Q, 1uL, &Q)) != MP_OKAY) goto cleanup; /* Q = prime - 1 */ mp_zero(&S); /* S = 0 */ - while (mp_iseven(&Q) != MP_NO) { - if ((res = mp_div_2(&Q, &Q)) != MP_OKAY) goto cleanup; + while (MP_IS_EVEN(&Q)) { + if ((err = mp_div_2(&Q, &Q)) != MP_OKAY) goto cleanup; /* Q = Q / 2 */ - if ((res = mp_add_d(&S, 1uL, &S)) != MP_OKAY) goto cleanup; + if ((err = mp_add_d(&S, 1uL, &S)) != MP_OKAY) goto cleanup; /* S = S + 1 */ } /* find a Z such that the Legendre symbol (Z|prime) == -1 */ - if ((res = mp_set_int(&Z, 2uL)) != MP_OKAY) goto cleanup; + mp_set_u32(&Z, 2u); /* Z = 2 */ - while (1) { - if ((res = mp_jacobi(&Z, prime, &legendre)) != MP_OKAY) goto cleanup; + for (;;) { + if ((err = mp_kronecker(&Z, prime, &legendre)) != MP_OKAY) goto cleanup; if (legendre == -1) break; - if ((res = mp_add_d(&Z, 1uL, &Z)) != MP_OKAY) goto cleanup; + if ((err = mp_add_d(&Z, 1uL, &Z)) != MP_OKAY) goto cleanup; /* Z = Z + 1 */ } - if ((res = mp_exptmod(&Z, &Q, prime, &C)) != MP_OKAY) goto cleanup; + if ((err = mp_exptmod(&Z, &Q, prime, &C)) != MP_OKAY) goto cleanup; /* C = Z ^ Q mod prime */ - if ((res = mp_add_d(&Q, 1uL, &t1)) != MP_OKAY) goto cleanup; - if ((res = mp_div_2(&t1, &t1)) != MP_OKAY) goto cleanup; + if ((err = mp_add_d(&Q, 1uL, &t1)) != MP_OKAY) goto cleanup; + if ((err = mp_div_2(&t1, &t1)) != MP_OKAY) goto cleanup; /* t1 = (Q + 1) / 2 */ - if ((res = mp_exptmod(n, &t1, prime, &R)) != MP_OKAY) goto cleanup; + if ((err = mp_exptmod(n, &t1, prime, &R)) != MP_OKAY) goto cleanup; /* R = n ^ ((Q + 1) / 2) mod prime */ - if ((res = mp_exptmod(n, &Q, prime, &T)) != MP_OKAY) goto cleanup; + if ((err = mp_exptmod(n, &Q, prime, &T)) != MP_OKAY) goto cleanup; /* T = n ^ Q mod prime */ - if ((res = mp_copy(&S, &M)) != MP_OKAY) goto cleanup; + if ((err = mp_copy(&S, &M)) != MP_OKAY) goto cleanup; /* M = S */ - if ((res = mp_set_int(&two, 2uL)) != MP_OKAY) goto cleanup; + mp_set_u32(&two, 2u); - res = MP_VAL; - while (1) { - if ((res = mp_copy(&T, &t1)) != MP_OKAY) goto cleanup; + for (;;) { + if ((err = mp_copy(&T, &t1)) != MP_OKAY) goto cleanup; i = 0; - while (1) { + for (;;) { if (mp_cmp_d(&t1, 1uL) == MP_EQ) break; - if ((res = mp_exptmod(&t1, &two, prime, &t1)) != MP_OKAY) goto cleanup; + if ((err = mp_exptmod(&t1, &two, prime, &t1)) != MP_OKAY) goto cleanup; i++; } if (i == 0u) { - if ((res = mp_copy(&R, ret)) != MP_OKAY) goto cleanup; - res = MP_OKAY; + if ((err = mp_copy(&R, ret)) != MP_OKAY) goto cleanup; + err = MP_OKAY; goto cleanup; } - if ((res = mp_sub_d(&M, i, &t1)) != MP_OKAY) goto cleanup; - if ((res = mp_sub_d(&t1, 1uL, &t1)) != MP_OKAY) goto cleanup; - if ((res = mp_exptmod(&two, &t1, prime, &t1)) != MP_OKAY) goto cleanup; + if ((err = mp_sub_d(&M, i, &t1)) != MP_OKAY) goto cleanup; + if ((err = mp_sub_d(&t1, 1uL, &t1)) != MP_OKAY) goto cleanup; + if ((err = mp_exptmod(&two, &t1, prime, &t1)) != MP_OKAY) goto cleanup; /* t1 = 2 ^ (M - i - 1) */ - if ((res = mp_exptmod(&C, &t1, prime, &t1)) != MP_OKAY) goto cleanup; + if ((err = mp_exptmod(&C, &t1, prime, &t1)) != MP_OKAY) goto cleanup; /* t1 = C ^ (2 ^ (M - i - 1)) mod prime */ - if ((res = mp_sqrmod(&t1, prime, &C)) != MP_OKAY) goto cleanup; + if ((err = mp_sqrmod(&t1, prime, &C)) != MP_OKAY) goto cleanup; /* C = (t1 * t1) mod prime */ - if ((res = mp_mulmod(&R, &t1, prime, &R)) != MP_OKAY) goto cleanup; + if ((err = mp_mulmod(&R, &t1, prime, &R)) != MP_OKAY) goto cleanup; /* R = (R * t1) mod prime */ - if ((res = mp_mulmod(&T, &C, prime, &T)) != MP_OKAY) goto cleanup; + if ((err = mp_mulmod(&T, &C, prime, &T)) != MP_OKAY) goto cleanup; /* T = (T * C) mod prime */ mp_set(&M, i); /* M = i */ @@ -121,11 +112,7 @@ cleanup: mp_clear_multi(&t1, &C, &Q, &S, &Z, &M, &T, &R, &two, NULL); - return res; + return err; } #endif - -/* ref: HEAD -> master, tag: v1.1.0 */ -/* git commit: 08549ad6bc8b0cede0b357a9c341c5c6473a9c55 */ -/* commit time: 2019-01-28 20:32:32 +0100 */