/* * BIP32 library, a Java implementation of BIP32 * Copyright (C) 2017 Alan Evans, NovaCrypto * * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * This program 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 General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program. If not, see <https://www.gnu.org/licenses/>. * * Original source: https://github.com/NovaCrypto/BIP32 * You can contact the authors via github issues. */ package com.github.ontio.crypto.bip32; import org.spongycastle.asn1.x9.X9ECParameters; import org.spongycastle.crypto.ec.CustomNamedCurves; import org.spongycastle.math.ec.ECPoint; import java.math.BigInteger; final class Secp256r1SC { static final X9ECParameters CURVE = CustomNamedCurves.getByName("secp256r1"); static BigInteger n() { return CURVE.getN(); } static byte[] pointSerP(final ECPoint point) { return point.getEncoded(true); } static byte[] pointSerP_gMultiply(final BigInteger p) { return pointSerP(gMultiply(p)); } static ECPoint gMultiplyAndAddPoint(final BigInteger p, final byte[] toAdd) { return gMultiply(p).add(decode(toAdd)); } private static ECPoint decode(final byte[] toAdd) { return CURVE.getCurve().decodePoint(toAdd); } private static ECPoint gMultiply(BigInteger p) { return CURVE.getG() .multiply(p); } }