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author | William Joye <wjoye@cfa.harvard.edu> | 2016-12-21 22:13:18 (GMT) |
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committer | William Joye <wjoye@cfa.harvard.edu> | 2016-12-21 22:13:18 (GMT) |
commit | 07e464099b99459d0a37757771791598ef3395d9 (patch) | |
tree | 4ba7d8aad13735e52f59bdce7ca5ba3151ebd7e3 /tcl8.6/libtommath/bn_mp_reduce.c | |
parent | deb3650e37f26f651f280e480c4df3d7dde87bae (diff) | |
download | blt-07e464099b99459d0a37757771791598ef3395d9.zip blt-07e464099b99459d0a37757771791598ef3395d9.tar.gz blt-07e464099b99459d0a37757771791598ef3395d9.tar.bz2 |
new subtree for tcl/tk
Diffstat (limited to 'tcl8.6/libtommath/bn_mp_reduce.c')
-rw-r--r-- | tcl8.6/libtommath/bn_mp_reduce.c | 96 |
1 files changed, 0 insertions, 96 deletions
diff --git a/tcl8.6/libtommath/bn_mp_reduce.c b/tcl8.6/libtommath/bn_mp_reduce.c deleted file mode 100644 index 4375e4e..0000000 --- a/tcl8.6/libtommath/bn_mp_reduce.c +++ /dev/null @@ -1,96 +0,0 @@ -#include <tommath.h> -#ifdef BN_MP_REDUCE_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://math.libtomcrypt.com - */ - -/* reduces x mod m, assumes 0 < x < m**2, mu is - * precomputed via mp_reduce_setup. - * From HAC pp.604 Algorithm 14.42 - */ -int mp_reduce (mp_int * x, mp_int * m, mp_int * mu) -{ - mp_int q; - int res, um = m->used; - - /* q = x */ - if ((res = mp_init_copy (&q, x)) != MP_OKAY) { - return res; - } - - /* q1 = x / b**(k-1) */ - mp_rshd (&q, um - 1); - - /* according to HAC this optimization is ok */ - if (((unsigned long) um) > (((mp_digit)1) << (DIGIT_BIT - 1))) { - if ((res = mp_mul (&q, mu, &q)) != MP_OKAY) { - goto CLEANUP; - } - } else { -#ifdef BN_S_MP_MUL_HIGH_DIGS_C - if ((res = s_mp_mul_high_digs (&q, mu, &q, um)) != MP_OKAY) { - goto CLEANUP; - } -#elif defined(BN_FAST_S_MP_MUL_HIGH_DIGS_C) - if ((res = fast_s_mp_mul_high_digs (&q, mu, &q, um)) != MP_OKAY) { - goto CLEANUP; - } -#else - { - res = MP_VAL; - goto CLEANUP; - } -#endif - } - - /* q3 = q2 / b**(k+1) */ - mp_rshd (&q, um + 1); - - /* x = x mod b**(k+1), quick (no division) */ - if ((res = mp_mod_2d (x, DIGIT_BIT * (um + 1), x)) != MP_OKAY) { - goto CLEANUP; - } - - /* q = q * m mod b**(k+1), quick (no division) */ - if ((res = s_mp_mul_digs (&q, m, &q, um + 1)) != MP_OKAY) { - goto CLEANUP; - } - - /* x = x - q */ - if ((res = mp_sub (x, &q, x)) != MP_OKAY) { - goto CLEANUP; - } - - /* If x < 0, add b**(k+1) to it */ - if (mp_cmp_d (x, 0) == MP_LT) { - mp_set (&q, 1); - if ((res = mp_lshd (&q, um + 1)) != MP_OKAY) - goto CLEANUP; - if ((res = mp_add (x, &q, x)) != MP_OKAY) - goto CLEANUP; - } - - /* Back off if it's too big */ - while (mp_cmp (x, m) != MP_LT) { - if ((res = s_mp_sub (x, m, x)) != MP_OKAY) { - goto CLEANUP; - } - } - -CLEANUP: - mp_clear (&q); - - return res; -} -#endif |