| /* |
| * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code 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 |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, 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. |
| */ |
| |
| package sun.security.ec; |
| |
| import java.math.BigInteger; |
| import java.security.InvalidKeyException; |
| import java.security.KeyRep; |
| import java.security.PublicKey; |
| import java.security.interfaces.XECPublicKey; |
| import java.security.spec.AlgorithmParameterSpec; |
| import java.security.spec.NamedParameterSpec; |
| import java.util.Arrays; |
| |
| import sun.security.util.BitArray; |
| import sun.security.x509.AlgorithmId; |
| import sun.security.x509.X509Key; |
| |
| public final class XDHPublicKeyImpl extends X509Key implements XECPublicKey { |
| |
| private static final long serialVersionUID = 1L; |
| |
| private final BigInteger u; |
| private final NamedParameterSpec paramSpec; |
| |
| XDHPublicKeyImpl(XECParameters params, BigInteger u) |
| throws InvalidKeyException { |
| |
| this.paramSpec = new NamedParameterSpec(params.getName()); |
| this.algid = new AlgorithmId(params.getOid()); |
| this.u = u.mod(params.getP()); |
| |
| byte[] u_arr = this.u.toByteArray(); |
| reverse(u_arr); |
| // u_arr may be too large or too small, depending on the value of u |
| u_arr = Arrays.copyOf(u_arr, params.getBytes()); |
| |
| setKey(new BitArray(u_arr.length * 8, u_arr)); |
| |
| checkLength(params); |
| } |
| |
| XDHPublicKeyImpl(byte[] encoded) throws InvalidKeyException { |
| decode(encoded); |
| |
| XECParameters params = |
| XECParameters.get(InvalidKeyException::new, algid); |
| this.paramSpec = new NamedParameterSpec(params.getName()); |
| // construct the BigInteger representation |
| byte[] u_arr = getKey().toByteArray(); |
| reverse(u_arr); |
| |
| // clear the extra bits |
| int bitsMod8 = params.getBits() % 8; |
| if (bitsMod8 != 0) { |
| int mask = (1 << bitsMod8) - 1; |
| u_arr[0] &= mask; |
| } |
| |
| this.u = new BigInteger(1, u_arr); |
| |
| checkLength(params); |
| } |
| |
| void checkLength(XECParameters params) throws InvalidKeyException { |
| |
| if (params.getBytes() * 8 != getKey().length()) { |
| throw new InvalidKeyException( |
| "key length must be " + params.getBytes()); |
| } |
| } |
| |
| @Override |
| public BigInteger getU() { |
| return u; |
| } |
| |
| @Override |
| public AlgorithmParameterSpec getParams() { |
| return paramSpec; |
| } |
| |
| @Override |
| public String getAlgorithm() { |
| return "XDH"; |
| } |
| |
| protected Object writeReplace() throws java.io.ObjectStreamException { |
| return new KeyRep(KeyRep.Type.PUBLIC, |
| getAlgorithm(), |
| getFormat(), |
| getEncoded()); |
| } |
| |
| private static void swap(byte[] arr, int i, int j) { |
| byte tmp = arr[i]; |
| arr[i] = arr[j]; |
| arr[j] = tmp; |
| } |
| |
| private static void reverse(byte [] arr) { |
| int i = 0; |
| int j = arr.length - 1; |
| |
| while (i < j) { |
| swap(arr, i, j); |
| i++; |
| j--; |
| } |
| } |
| } |
| |