crypto/ecc/ecp_mont.c

f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers/*
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers * ***** BEGIN LICENSE BLOCK *****
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers * Version: MPL 1.1/GPL 2.0/LGPL 2.1
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers *
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers * The contents of this file are subject to the Mozilla Public License Version
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers * 1.1 (the "License"); you may not use this file except in compliance with
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers * the License. You may obtain a copy of the License at
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers * http://www.mozilla.org/MPL/
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers *
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers * Software distributed under the License is distributed on an "AS IS" basis,
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers * for the specific language governing rights and limitations under the
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers * License.
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers *
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers * The Original Code is the elliptic curve math library.
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers *
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers * The Initial Developer of the Original Code is
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers * Sun Microsystems, Inc.
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers * Portions created by the Initial Developer are Copyright (C) 2003
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers * the Initial Developer. All Rights Reserved.
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers *
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers * Contributor(s):
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers *   Douglas Stebila <douglas@stebila.ca>, Sun Microsystems Laboratories
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers *
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers * Alternatively, the contents of this file may be used under the terms of
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers * either the GNU General Public License Version 2 or later (the "GPL"), or
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers * in which case the provisions of the GPL or the LGPL are applicable instead
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers * of those above. If you wish to allow use of your version of this file only
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers * under the terms of either the GPL or the LGPL, and not to allow others to
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers * use your version of this file under the terms of the MPL, indicate your
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers * decision by deleting the provisions above and replace them with the notice
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers * and other provisions required by the GPL or the LGPL. If you do not delete
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers * the provisions above, a recipient may use your version of this file under
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers * the terms of any one of the MPL, the GPL or the LGPL.
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers *
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers * ***** END LICENSE BLOCK ***** */
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers/*
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers * Use is subject to license terms.
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers *
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers * Sun elects to use this software under the MPL license.
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers */
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers#pragma ident   "%Z%%M% %I% %E% SMI"
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers/* Uses Montgomery reduction for field arithmetic.  See mpi/mpmontg.c for
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers * code implementation. */
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers#include "mpi.h"
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers#include "mplogic.h"
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers#include "mpi-priv.h"
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers#include "ecl-priv.h"
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers#include "ecp.h"
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers#ifndef _KERNEL
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers#include <stdlib.h>
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers#include <stdio.h>
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers#endif
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers/* Construct a generic GFMethod for arithmetic over prime fields with
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers * irreducible irr. */
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowersGFMethod *
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowersGFMethod_consGFp_mont(const mp_int *irr)
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers{
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers    mp_err res = MP_OKAY;
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers    int i;
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers    GFMethod *meth = NULL;
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers    mp_mont_modulus *mmm;
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers    meth = GFMethod_consGFp(irr);
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers    if (meth == NULL)
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers        return NULL;
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers#ifdef _KERNEL
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers    mmm = (mp_mont_modulus *) kmem_alloc(sizeof(mp_mont_modulus),
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers        FLAG(irr));
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers#else
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers    mmm = (mp_mont_modulus *) malloc(sizeof(mp_mont_modulus));
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers#endif
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers    if (mmm == NULL) {
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers        res = MP_MEM;
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers        goto CLEANUP;
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers    }
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers    meth->field_mul = &ec_GFp_mul_mont;
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers    meth->field_sqr = &ec_GFp_sqr_mont;
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers    meth->field_div = &ec_GFp_div_mont;
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers    meth->field_enc = &ec_GFp_enc_mont;
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers    meth->field_dec = &ec_GFp_dec_mont;
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers    meth->extra1 = mmm;
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers    meth->extra2 = NULL;
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers    meth->extra_free = &ec_GFp_extra_free_mont;
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers    mmm->N = meth->irr;
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers    i = mpl_significant_bits(&meth->irr);
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers    i += MP_DIGIT_BIT - 1;
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers    mmm->b = i - i % MP_DIGIT_BIT;
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers    mmm->n0prime = 0 - s_mp_invmod_radix(MP_DIGIT(&meth->irr, 0));
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers  CLEANUP:
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers    if (res != MP_OKAY) {
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers        GFMethod_free(meth);
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers        return NULL;
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers    }
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers    return meth;
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers}
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers/* Wrapper functions for generic prime field arithmetic. */
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers/* Field multiplication using Montgomery reduction. */
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowersmp_err
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowersec_GFp_mul_mont(const mp_int *a, const mp_int *b, mp_int *r,
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers                const GFMethod *meth)
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers{
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers    mp_err res = MP_OKAY;
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers#ifdef MP_MONT_USE_MP_MUL
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers    /* if MP_MONT_USE_MP_MUL is defined, then the function s_mp_mul_mont
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers     * is not implemented and we have to use mp_mul and s_mp_redc directly
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers     */
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers    MP_CHECKOK(mp_mul(a, b, r));
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers    MP_CHECKOK(s_mp_redc(r, (mp_mont_modulus *) meth->extra1));
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers#else
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers    mp_int s;
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers    MP_DIGITS(&s) = 0;
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers    /* s_mp_mul_mont doesn't allow source and destination to be the same */
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers    if ((a == r) || (b == r)) {
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers        MP_CHECKOK(mp_init(&s, FLAG(a)));
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers        MP_CHECKOK(s_mp_mul_mont
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers                   (a, b, &s, (mp_mont_modulus *) meth->extra1));
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers        MP_CHECKOK(mp_copy(&s, r));
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers        mp_clear(&s);
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers    } else {
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers        return s_mp_mul_mont(a, b, r, (mp_mont_modulus *) meth->extra1);
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers    }
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers#endif
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers  CLEANUP:
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers    return res;
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers}
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers/* Field squaring using Montgomery reduction. */
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowersmp_err
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowersec_GFp_sqr_mont(const mp_int *a, mp_int *r, const GFMethod *meth)
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers{
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers    return ec_GFp_mul_mont(a, a, r, meth);
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers}
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers/* Field division using Montgomery reduction. */
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowersmp_err
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowersec_GFp_div_mont(const mp_int *a, const mp_int *b, mp_int *r,
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers                const GFMethod *meth)
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers{
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers    mp_err res = MP_OKAY;
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers    /* if A=aZ represents a encoded in montgomery coordinates with Z and #
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers     * and \ respectively represent multiplication and division in
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers     * montgomery coordinates, then A\B = (a/b)Z = (A/B)Z and Binv =
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers     * (1/b)Z = (1/B)(Z^2) where B # Binv = Z */
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers    MP_CHECKOK(ec_GFp_div(a, b, r, meth));
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers    MP_CHECKOK(ec_GFp_enc_mont(r, r, meth));
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers    if (a == NULL) {
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers        MP_CHECKOK(ec_GFp_enc_mont(r, r, meth));
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers    }
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers  CLEANUP:
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers    return res;
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers}
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers/* Encode a field element in Montgomery form. See s_mp_to_mont in
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers * mpi/mpmontg.c */
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowersmp_err
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowersec_GFp_enc_mont(const mp_int *a, mp_int *r, const GFMethod *meth)
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers{
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers    mp_mont_modulus *mmm;
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers    mp_err res = MP_OKAY;
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers    mmm = (mp_mont_modulus *) meth->extra1;
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers    MP_CHECKOK(mpl_lsh(a, r, mmm->b));
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers    MP_CHECKOK(mp_mod(r, &mmm->N, r));
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers  CLEANUP:
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers    return res;
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers}
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers/* Decode a field element from Montgomery form. */
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowersmp_err
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowersec_GFp_dec_mont(const mp_int *a, mp_int *r, const GFMethod *meth)
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers{
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers    mp_err res = MP_OKAY;
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers    if (a != r) {
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers        MP_CHECKOK(mp_copy(a, r));
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers    }
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers    MP_CHECKOK(s_mp_redc(r, (mp_mont_modulus *) meth->extra1));
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers  CLEANUP:
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers    return res;
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers}
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers/* Free the memory allocated to the extra fields of Montgomery GFMethod
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers * object. */
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowersvoid
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowersec_GFp_extra_free_mont(GFMethod *meth)
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers{
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers    if (meth->extra1 != NULL) {
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers#ifdef _KERNEL
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers        kmem_free(meth->extra1, sizeof(mp_mont_modulus));
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers#else
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers        free(meth->extra1);
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers#endif
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers        meth->extra1 = NULL;
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers    }
f9fbec18f5b458b560ecf45d3db8e8bd56bf6942mcpowers}