| /* |
| * 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 163-bit curve. Assumes reduction |
| * polynomial with terms {163, 7, 6, 3, 0}. */ |
| mp_err |
| ec_GF2m_163_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) < 6) { |
| MP_CHECKOK(s_mp_pad(r, 6)); |
| } |
| u = MP_DIGITS(r); |
| MP_USED(r) = 6; |
| |
| /* u[5] only has 6 significant bits */ |
| z = u[5]; |
| u[2] ^= (z << 36) ^ (z << 35) ^ (z << 32) ^ (z << 29); |
| z = u[4]; |
| u[2] ^= (z >> 28) ^ (z >> 29) ^ (z >> 32) ^ (z >> 35); |
| u[1] ^= (z << 36) ^ (z << 35) ^ (z << 32) ^ (z << 29); |
| z = u[3]; |
| u[1] ^= (z >> 28) ^ (z >> 29) ^ (z >> 32) ^ (z >> 35); |
| u[0] ^= (z << 36) ^ (z << 35) ^ (z << 32) ^ (z << 29); |
| z = u[2] >> 35; /* z only has 29 significant bits */ |
| u[0] ^= (z << 7) ^ (z << 6) ^ (z << 3) ^ z; |
| /* clear bits above 163 */ |
| u[5] = u[4] = u[3] = 0; |
| u[2] ^= z << 35; |
| #else |
| if (MP_USED(r) < 11) { |
| MP_CHECKOK(s_mp_pad(r, 11)); |
| } |
| u = MP_DIGITS(r); |
| MP_USED(r) = 11; |
| |
| /* u[11] only has 6 significant bits */ |
| z = u[10]; |
| u[5] ^= (z << 4) ^ (z << 3) ^ z ^ (z >> 3); |
| u[4] ^= (z << 29); |
| z = u[9]; |
| u[5] ^= (z >> 28) ^ (z >> 29); |
| u[4] ^= (z << 4) ^ (z << 3) ^ z ^ (z >> 3); |
| u[3] ^= (z << 29); |
| z = u[8]; |
| u[4] ^= (z >> 28) ^ (z >> 29); |
| u[3] ^= (z << 4) ^ (z << 3) ^ z ^ (z >> 3); |
| u[2] ^= (z << 29); |
| z = u[7]; |
| u[3] ^= (z >> 28) ^ (z >> 29); |
| u[2] ^= (z << 4) ^ (z << 3) ^ z ^ (z >> 3); |
| u[1] ^= (z << 29); |
| z = u[6]; |
| u[2] ^= (z >> 28) ^ (z >> 29); |
| u[1] ^= (z << 4) ^ (z << 3) ^ z ^ (z >> 3); |
| u[0] ^= (z << 29); |
| z = u[5] >> 3; /* z only has 29 significant bits */ |
| u[1] ^= (z >> 25) ^ (z >> 26); |
| u[0] ^= (z << 7) ^ (z << 6) ^ (z << 3) ^ z; |
| /* clear bits above 163 */ |
| u[11] = u[10] = u[9] = u[8] = u[7] = u[6] = 0; |
| u[5] ^= z << 3; |
| #endif |
| s_mp_clamp(r); |
| |
| CLEANUP: |
| return res; |
| } |
| |
| /* Fast squaring for polynomials over a 163-bit curve. Assumes reduction |
| * polynomial with terms {163, 7, 6, 3, 0}. */ |
| mp_err |
| ec_GF2m_163_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) < 3) { |
| return mp_bsqrmod(a, meth->irr_arr, r); |
| } |
| if (MP_USED(r) < 6) { |
| MP_CHECKOK(s_mp_pad(r, 6)); |
| } |
| MP_USED(r) = 6; |
| #else |
| if (MP_USED(a) < 6) { |
| return mp_bsqrmod(a, meth->irr_arr, r); |
| } |
| if (MP_USED(r) < 12) { |
| MP_CHECKOK(s_mp_pad(r, 12)); |
| } |
| MP_USED(r) = 12; |
| #endif |
| u = MP_DIGITS(r); |
| |
| #ifdef ECL_THIRTY_TWO_BIT |
| 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]); |
| u[6] = gf2m_SQR0(v[3]); |
| #endif |
| 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_163_mod(r, r, meth); |
| |
| CLEANUP: |
| return res; |
| } |
| |
| /* Fast multiplication for polynomials over a 163-bit curve. Assumes |
| * reduction polynomial with terms {163, 7, 6, 3, 0}. */ |
| mp_err |
| ec_GF2m_163_mul(const mp_int *a, const mp_int *b, mp_int *r, |
| const GFMethod *meth) |
| { |
| mp_err res = MP_OKAY; |
| mp_digit a2 = 0, a1 = 0, a0, b2 = 0, b1 = 0, b0; |
| |
| #ifdef ECL_THIRTY_TWO_BIT |
| mp_digit a5 = 0, a4 = 0, a3 = 0, b5 = 0, b4 = 0, b3 = 0; |
| mp_digit rm[6]; |
| #endif |
| |
| if (a == b) { |
| return ec_GF2m_163_sqr(a, r, meth); |
| } else { |
| switch (MP_USED(a)) { |
| #ifdef ECL_THIRTY_TWO_BIT |
| case 6: |
| a5 = MP_DIGIT(a, 5); |
| case 5: |
| a4 = MP_DIGIT(a, 4); |
| case 4: |
| a3 = MP_DIGIT(a, 3); |
| #endif |
| 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 6: |
| b5 = MP_DIGIT(b, 5); |
| case 5: |
| b4 = MP_DIGIT(b, 4); |
| case 4: |
| b3 = MP_DIGIT(b, 3); |
| #endif |
| 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, 6)); |
| s_bmul_3x3(MP_DIGITS(r), a2, a1, a0, b2, b1, b0); |
| MP_USED(r) = 6; |
| s_mp_clamp(r); |
| #else |
| MP_CHECKOK(s_mp_pad(r, 12)); |
| s_bmul_3x3(MP_DIGITS(r) + 6, a5, a4, a3, b5, b4, b3); |
| s_bmul_3x3(MP_DIGITS(r), a2, a1, a0, b2, b1, b0); |
| s_bmul_3x3(rm, a5 ^ a2, a4 ^ a1, a3 ^ a0, b5 ^ b2, b4 ^ b1, |
| b3 ^ b0); |
| rm[5] ^= MP_DIGIT(r, 5) ^ MP_DIGIT(r, 11); |
| rm[4] ^= MP_DIGIT(r, 4) ^ MP_DIGIT(r, 10); |
| rm[3] ^= MP_DIGIT(r, 3) ^ MP_DIGIT(r, 9); |
| rm[2] ^= MP_DIGIT(r, 2) ^ MP_DIGIT(r, 8); |
| rm[1] ^= MP_DIGIT(r, 1) ^ MP_DIGIT(r, 7); |
| rm[0] ^= MP_DIGIT(r, 0) ^ MP_DIGIT(r, 6); |
| MP_DIGIT(r, 8) ^= rm[5]; |
| MP_DIGIT(r, 7) ^= rm[4]; |
| MP_DIGIT(r, 6) ^= rm[3]; |
| MP_DIGIT(r, 5) ^= rm[2]; |
| MP_DIGIT(r, 4) ^= rm[1]; |
| MP_DIGIT(r, 3) ^= rm[0]; |
| MP_USED(r) = 12; |
| s_mp_clamp(r); |
| #endif |
| return ec_GF2m_163_mod(r, r, meth); |
| } |
| |
| CLEANUP: |
| return res; |
| } |
| |
| /* Wire in fast field arithmetic for 163-bit curves. */ |
| mp_err |
| ec_group_set_gf2m163(ECGroup *group, ECCurveName name) |
| { |
| group->meth->field_mod = &ec_GF2m_163_mod; |
| group->meth->field_mul = &ec_GF2m_163_mul; |
| group->meth->field_sqr = &ec_GF2m_163_sqr; |
| return MP_OKAY; |
| } |
