| /* |
| * 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 233-bit curve. Assumes reduction |
| * polynomial with terms {233, 74, 0}. */ |
| mp_err |
| ec_GF2m_233_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) < 8) { |
| MP_CHECKOK(s_mp_pad(r, 8)); |
| } |
| u = MP_DIGITS(r); |
| MP_USED(r) = 8; |
| |
| /* u[7] only has 18 significant bits */ |
| z = u[7]; |
| u[4] ^= (z << 33) ^ (z >> 41); |
| u[3] ^= (z << 23); |
| z = u[6]; |
| u[4] ^= (z >> 31); |
| u[3] ^= (z << 33) ^ (z >> 41); |
| u[2] ^= (z << 23); |
| z = u[5]; |
| u[3] ^= (z >> 31); |
| u[2] ^= (z << 33) ^ (z >> 41); |
| u[1] ^= (z << 23); |
| z = u[4]; |
| u[2] ^= (z >> 31); |
| u[1] ^= (z << 33) ^ (z >> 41); |
| u[0] ^= (z << 23); |
| z = u[3] >> 41; /* z only has 23 significant bits */ |
| u[1] ^= (z << 10); |
| u[0] ^= z; |
| /* clear bits above 233 */ |
| u[7] = u[6] = u[5] = u[4] = 0; |
| u[3] ^= z << 41; |
| #else |
| if (MP_USED(r) < 15) { |
| MP_CHECKOK(s_mp_pad(r, 15)); |
| } |
| u = MP_DIGITS(r); |
| MP_USED(r) = 15; |
| |
| /* u[14] only has 18 significant bits */ |
| z = u[14]; |
| u[9] ^= (z << 1); |
| u[7] ^= (z >> 9); |
| u[6] ^= (z << 23); |
| z = u[13]; |
| u[9] ^= (z >> 31); |
| u[8] ^= (z << 1); |
| u[6] ^= (z >> 9); |
| u[5] ^= (z << 23); |
| z = u[12]; |
| u[8] ^= (z >> 31); |
| u[7] ^= (z << 1); |
| u[5] ^= (z >> 9); |
| u[4] ^= (z << 23); |
| z = u[11]; |
| u[7] ^= (z >> 31); |
| u[6] ^= (z << 1); |
| u[4] ^= (z >> 9); |
| u[3] ^= (z << 23); |
| z = u[10]; |
| u[6] ^= (z >> 31); |
| u[5] ^= (z << 1); |
| u[3] ^= (z >> 9); |
| u[2] ^= (z << 23); |
| z = u[9]; |
| u[5] ^= (z >> 31); |
| u[4] ^= (z << 1); |
| u[2] ^= (z >> 9); |
| u[1] ^= (z << 23); |
| z = u[8]; |
| u[4] ^= (z >> 31); |
| u[3] ^= (z << 1); |
| u[1] ^= (z >> 9); |
| u[0] ^= (z << 23); |
| z = u[7] >> 9; /* z only has 23 significant bits */ |
| u[3] ^= (z >> 22); |
| u[2] ^= (z << 10); |
| u[0] ^= z; |
| /* clear bits above 233 */ |
| u[14] = u[13] = u[12] = u[11] = u[10] = u[9] = u[8] = 0; |
| u[7] ^= z << 9; |
| #endif |
| s_mp_clamp(r); |
| |
| CLEANUP: |
| return res; |
| } |
| |
| /* Fast squaring for polynomials over a 233-bit curve. Assumes reduction |
| * polynomial with terms {233, 74, 0}. */ |
| mp_err |
| ec_GF2m_233_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) < 8) { |
| MP_CHECKOK(s_mp_pad(r, 8)); |
| } |
| MP_USED(r) = 8; |
| #else |
| if (MP_USED(a) < 8) { |
| return mp_bsqrmod(a, meth->irr_arr, r); |
| } |
| if (MP_USED(r) < 15) { |
| MP_CHECKOK(s_mp_pad(r, 15)); |
| } |
| MP_USED(r) = 15; |
| #endif |
| u = MP_DIGITS(r); |
| |
| #ifdef ECL_THIRTY_TWO_BIT |
| u[14] = gf2m_SQR0(v[7]); |
| u[13] = gf2m_SQR1(v[6]); |
| 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]); |
| #endif |
| u[7] = gf2m_SQR1(v[3]); |
| 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_233_mod(r, r, meth); |
| |
| CLEANUP: |
| return res; |
| } |
| |
| /* Fast multiplication for polynomials over a 233-bit curve. Assumes |
| * reduction polynomial with terms {233, 74, 0}. */ |
| mp_err |
| ec_GF2m_233_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 a7 = 0, a6 = 0, a5 = 0, a4 = 0, b7 = 0, b6 = 0, b5 = 0, b4 = |
| 0; |
| mp_digit rm[8]; |
| #endif |
| |
| if (a == b) { |
| return ec_GF2m_233_sqr(a, r, meth); |
| } else { |
| switch (MP_USED(a)) { |
| #ifdef ECL_THIRTY_TWO_BIT |
| case 8: |
| a7 = MP_DIGIT(a, 7); |
| 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 8: |
| b7 = MP_DIGIT(b, 7); |
| 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, 16)); |
| s_bmul_4x4(MP_DIGITS(r) + 8, a7, a6, a5, a4, b7, b6, b5, b4); |
| s_bmul_4x4(MP_DIGITS(r), a3, a2, a1, a0, b3, b2, b1, b0); |
| s_bmul_4x4(rm, a7 ^ a3, a6 ^ a2, a5 ^ a1, a4 ^ a0, b7 ^ b3, |
| b6 ^ b2, b5 ^ b1, b4 ^ b0); |
| rm[7] ^= MP_DIGIT(r, 7) ^ MP_DIGIT(r, 15); |
| rm[6] ^= MP_DIGIT(r, 6) ^ MP_DIGIT(r, 14); |
| 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) = 16; |
| s_mp_clamp(r); |
| #endif |
| return ec_GF2m_233_mod(r, r, meth); |
| } |
| |
| CLEANUP: |
| return res; |
| } |
| |
| /* Wire in fast field arithmetic for 233-bit curves. */ |
| mp_err |
| ec_group_set_gf2m233(ECGroup *group, ECCurveName name) |
| { |
| group->meth->field_mod = &ec_GF2m_233_mod; |
| group->meth->field_mul = &ec_GF2m_233_mul; |
| group->meth->field_sqr = &ec_GF2m_233_sqr; |
| return MP_OKAY; |
| } |
