| /* | |
| * Copyright (c) 2007, 2011, Oracle and/or its affiliates. All rights reserved. | |
| * Use is subject to license terms. | |
| * | |
| * This library is free software; you can redistribute it and/or | |
| * modify it under the terms of the GNU Lesser General Public | |
| * License as published by the Free Software Foundation; either | |
| * version 2.1 of the License, or (at your option) any later version. | |
| * | |
| * This library is distributed in the hope that it will be useful, | |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
| * Lesser General Public License for more details. | |
| * | |
| * You should have received a copy of the GNU Lesser General Public License | |
| * along with this library; if not, write to the Free Software Foundation, | |
| * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. | |
| * | |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA | |
| * or visit www.oracle.com if you need additional information or have any | |
| * questions. | |
| */ | |
| /* ********************************************************************* | |
| * | |
| * The Original Code is the elliptic curve math library for binary polynomial field curves. | |
| * | |
| * The Initial Developer of the Original Code is | |
| * Sun Microsystems, Inc. | |
| * Portions created by the Initial Developer are Copyright (C) 2003 | |
| * the Initial Developer. All Rights Reserved. | |
| * | |
| * Contributor(s): | |
| * Sheueling Chang-Shantz <sheueling.chang@sun.com>, | |
| * Stephen Fung <fungstep@hotmail.com>, and | |
| * Douglas Stebila <douglas@stebila.ca>, Sun Microsystems Laboratories. | |
| * | |
| *********************************************************************** */ | |
| #include "ec2.h" | |
| #include "mp_gf2m.h" | |
| #include "mp_gf2m-priv.h" | |
| #include "mpi.h" | |
| #include "mpi-priv.h" | |
| #ifndef _KERNEL | |
| #include <stdlib.h> | |
| #endif | |
| /* Fast reduction for polynomials over a 193-bit curve. Assumes reduction | |
| * polynomial with terms {193, 15, 0}. */ | |
| mp_err | |
| ec_GF2m_193_mod(const mp_int *a, mp_int *r, const GFMethod *meth) | |
| { | |
| mp_err res = MP_OKAY; | |
| mp_digit *u, z; | |
| if (a != r) { | |
| MP_CHECKOK(mp_copy(a, r)); | |
| } | |
| #ifdef ECL_SIXTY_FOUR_BIT | |
| if (MP_USED(r) < 7) { | |
| MP_CHECKOK(s_mp_pad(r, 7)); | |
| } | |
| u = MP_DIGITS(r); | |
| MP_USED(r) = 7; | |
| /* u[6] only has 2 significant bits */ | |
| z = u[6]; | |
| u[3] ^= (z << 14) ^ (z >> 1); | |
| u[2] ^= (z << 63); | |
| z = u[5]; | |
| u[3] ^= (z >> 50); | |
| u[2] ^= (z << 14) ^ (z >> 1); | |
| u[1] ^= (z << 63); | |
| z = u[4]; | |
| u[2] ^= (z >> 50); | |
| u[1] ^= (z << 14) ^ (z >> 1); | |
| u[0] ^= (z << 63); | |
| z = u[3] >> 1; /* z only has 63 significant bits */ | |
| u[1] ^= (z >> 49); | |
| u[0] ^= (z << 15) ^ z; | |
| /* clear bits above 193 */ | |
| u[6] = u[5] = u[4] = 0; | |
| u[3] ^= z << 1; | |
| #else | |
| if (MP_USED(r) < 13) { | |
| MP_CHECKOK(s_mp_pad(r, 13)); | |
| } | |
| u = MP_DIGITS(r); | |
| MP_USED(r) = 13; | |
| /* u[12] only has 2 significant bits */ | |
| z = u[12]; | |
| u[6] ^= (z << 14) ^ (z >> 1); | |
| u[5] ^= (z << 31); | |
| z = u[11]; | |
| u[6] ^= (z >> 18); | |
| u[5] ^= (z << 14) ^ (z >> 1); | |
| u[4] ^= (z << 31); | |
| z = u[10]; | |
| u[5] ^= (z >> 18); | |
| u[4] ^= (z << 14) ^ (z >> 1); | |
| u[3] ^= (z << 31); | |
| z = u[9]; | |
| u[4] ^= (z >> 18); | |
| u[3] ^= (z << 14) ^ (z >> 1); | |
| u[2] ^= (z << 31); | |
| z = u[8]; | |
| u[3] ^= (z >> 18); | |
| u[2] ^= (z << 14) ^ (z >> 1); | |
| u[1] ^= (z << 31); | |
| z = u[7]; | |
| u[2] ^= (z >> 18); | |
| u[1] ^= (z << 14) ^ (z >> 1); | |
| u[0] ^= (z << 31); | |
| z = u[6] >> 1; /* z only has 31 significant bits */ | |
| u[1] ^= (z >> 17); | |
| u[0] ^= (z << 15) ^ z; | |
| /* clear bits above 193 */ | |
| u[12] = u[11] = u[10] = u[9] = u[8] = u[7] = 0; | |
| u[6] ^= z << 1; | |
| #endif | |
| s_mp_clamp(r); | |
| CLEANUP: | |
| return res; | |
| } | |
| /* Fast squaring for polynomials over a 193-bit curve. Assumes reduction | |
| * polynomial with terms {193, 15, 0}. */ | |
| mp_err | |
| ec_GF2m_193_sqr(const mp_int *a, mp_int *r, const GFMethod *meth) | |
| { | |
| mp_err res = MP_OKAY; | |
| mp_digit *u, *v; | |
| v = MP_DIGITS(a); | |
| #ifdef ECL_SIXTY_FOUR_BIT | |
| if (MP_USED(a) < 4) { | |
| return mp_bsqrmod(a, meth->irr_arr, r); | |
| } | |
| if (MP_USED(r) < 7) { | |
| MP_CHECKOK(s_mp_pad(r, 7)); | |
| } | |
| MP_USED(r) = 7; | |
| #else | |
| if (MP_USED(a) < 7) { | |
| return mp_bsqrmod(a, meth->irr_arr, r); | |
| } | |
| if (MP_USED(r) < 13) { | |
| MP_CHECKOK(s_mp_pad(r, 13)); | |
| } | |
| MP_USED(r) = 13; | |
| #endif | |
| u = MP_DIGITS(r); | |
| #ifdef ECL_THIRTY_TWO_BIT | |
| u[12] = gf2m_SQR0(v[6]); | |
| u[11] = gf2m_SQR1(v[5]); | |
| u[10] = gf2m_SQR0(v[5]); | |
| u[9] = gf2m_SQR1(v[4]); | |
| u[8] = gf2m_SQR0(v[4]); | |
| u[7] = gf2m_SQR1(v[3]); | |
| #endif | |
| u[6] = gf2m_SQR0(v[3]); | |
| u[5] = gf2m_SQR1(v[2]); | |
| u[4] = gf2m_SQR0(v[2]); | |
| u[3] = gf2m_SQR1(v[1]); | |
| u[2] = gf2m_SQR0(v[1]); | |
| u[1] = gf2m_SQR1(v[0]); | |
| u[0] = gf2m_SQR0(v[0]); | |
| return ec_GF2m_193_mod(r, r, meth); | |
| CLEANUP: | |
| return res; | |
| } | |
| /* Fast multiplication for polynomials over a 193-bit curve. Assumes | |
| * reduction polynomial with terms {193, 15, 0}. */ | |
| mp_err | |
| ec_GF2m_193_mul(const mp_int *a, const mp_int *b, mp_int *r, | |
| const GFMethod *meth) | |
| { | |
| mp_err res = MP_OKAY; | |
| mp_digit a3 = 0, a2 = 0, a1 = 0, a0, b3 = 0, b2 = 0, b1 = 0, b0; | |
| #ifdef ECL_THIRTY_TWO_BIT | |
| mp_digit a6 = 0, a5 = 0, a4 = 0, b6 = 0, b5 = 0, b4 = 0; | |
| mp_digit rm[8]; | |
| #endif | |
| if (a == b) { | |
| return ec_GF2m_193_sqr(a, r, meth); | |
| } else { | |
| switch (MP_USED(a)) { | |
| #ifdef ECL_THIRTY_TWO_BIT | |
| case 7: | |
| a6 = MP_DIGIT(a, 6); | |
| case 6: | |
| a5 = MP_DIGIT(a, 5); | |
| case 5: | |
| a4 = MP_DIGIT(a, 4); | |
| #endif | |
| case 4: | |
| a3 = MP_DIGIT(a, 3); | |
| case 3: | |
| a2 = MP_DIGIT(a, 2); | |
| case 2: | |
| a1 = MP_DIGIT(a, 1); | |
| default: | |
| a0 = MP_DIGIT(a, 0); | |
| } | |
| switch (MP_USED(b)) { | |
| #ifdef ECL_THIRTY_TWO_BIT | |
| case 7: | |
| b6 = MP_DIGIT(b, 6); | |
| case 6: | |
| b5 = MP_DIGIT(b, 5); | |
| case 5: | |
| b4 = MP_DIGIT(b, 4); | |
| #endif | |
| case 4: | |
| b3 = MP_DIGIT(b, 3); | |
| case 3: | |
| b2 = MP_DIGIT(b, 2); | |
| case 2: | |
| b1 = MP_DIGIT(b, 1); | |
| default: | |
| b0 = MP_DIGIT(b, 0); | |
| } | |
| #ifdef ECL_SIXTY_FOUR_BIT | |
| MP_CHECKOK(s_mp_pad(r, 8)); | |
| s_bmul_4x4(MP_DIGITS(r), a3, a2, a1, a0, b3, b2, b1, b0); | |
| MP_USED(r) = 8; | |
| s_mp_clamp(r); | |
| #else | |
| MP_CHECKOK(s_mp_pad(r, 14)); | |
| s_bmul_3x3(MP_DIGITS(r) + 8, a6, a5, a4, b6, b5, b4); | |
| s_bmul_4x4(MP_DIGITS(r), a3, a2, a1, a0, b3, b2, b1, b0); | |
| s_bmul_4x4(rm, a3, a6 ^ a2, a5 ^ a1, a4 ^ a0, b3, b6 ^ b2, b5 ^ b1, | |
| b4 ^ b0); | |
| rm[7] ^= MP_DIGIT(r, 7); | |
| rm[6] ^= MP_DIGIT(r, 6); | |
| rm[5] ^= MP_DIGIT(r, 5) ^ MP_DIGIT(r, 13); | |
| rm[4] ^= MP_DIGIT(r, 4) ^ MP_DIGIT(r, 12); | |
| rm[3] ^= MP_DIGIT(r, 3) ^ MP_DIGIT(r, 11); | |
| rm[2] ^= MP_DIGIT(r, 2) ^ MP_DIGIT(r, 10); | |
| rm[1] ^= MP_DIGIT(r, 1) ^ MP_DIGIT(r, 9); | |
| rm[0] ^= MP_DIGIT(r, 0) ^ MP_DIGIT(r, 8); | |
| MP_DIGIT(r, 11) ^= rm[7]; | |
| MP_DIGIT(r, 10) ^= rm[6]; | |
| MP_DIGIT(r, 9) ^= rm[5]; | |
| MP_DIGIT(r, 8) ^= rm[4]; | |
| MP_DIGIT(r, 7) ^= rm[3]; | |
| MP_DIGIT(r, 6) ^= rm[2]; | |
| MP_DIGIT(r, 5) ^= rm[1]; | |
| MP_DIGIT(r, 4) ^= rm[0]; | |
| MP_USED(r) = 14; | |
| s_mp_clamp(r); | |
| #endif | |
| return ec_GF2m_193_mod(r, r, meth); | |
| } | |
| CLEANUP: | |
| return res; | |
| } | |
| /* Wire in fast field arithmetic for 193-bit curves. */ | |
| mp_err | |
| ec_group_set_gf2m193(ECGroup *group, ECCurveName name) | |
| { | |
| group->meth->field_mod = &ec_GF2m_193_mod; | |
| group->meth->field_mul = &ec_GF2m_193_mul; | |
| group->meth->field_sqr = &ec_GF2m_193_sqr; | |
| return MP_OKAY; | |
| } |