/* * Copyright (c) 2009, 2017, 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.io.IOException; import java.math.BigInteger; import java.security.*; import java.security.spec.AlgorithmParameterSpec; import java.security.spec.ECGenParameterSpec; import java.security.spec.ECParameterSpec; import java.security.spec.ECPoint; import java.security.spec.InvalidParameterSpecException; import sun.security.ec.NamedCurve; import sun.security.ec.ECParameters; import sun.security.ec.ECPrivateKeyImpl; import sun.security.ec.ECPublicKeyImpl; import sun.security.jca.JCAUtil; import sun.security.util.ECUtil; import static sun.security.util.SecurityProviderConstants.DEF_EC_KEY_SIZE; /** * EC keypair generator. * Standard algorithm, minimum key length is 112 bits, maximum is 571 bits. * * @since 1.7 */ public final class ECKeyPairGenerator extends KeyPairGeneratorSpi { private static final int KEY_SIZE_MIN = 112; // min bits (see ecc_impl.h) private static final int KEY_SIZE_MAX = 571; // max bits (see ecc_impl.h) // used to seed the keypair generator private SecureRandom random; // size of the key to generate, KEY_SIZE_MIN <= keySize <= KEY_SIZE_MAX private int keySize; // parameters specified via init, if any private AlgorithmParameterSpec params = null; /** * Constructs a new ECKeyPairGenerator. */ public ECKeyPairGenerator() { // initialize to default in case the app does not call initialize() initialize(DEF_EC_KEY_SIZE, null); } // initialize the generator. See JCA doc @Override public void initialize(int keySize, SecureRandom random) { checkKeySize(keySize); this.params = ECUtil.getECParameterSpec(null, keySize); if (params == null) { throw new InvalidParameterException( "No EC parameters available for key size " + keySize + " bits"); } this.random = random; } // second initialize method. See JCA doc @Override public void initialize(AlgorithmParameterSpec params, SecureRandom random) throws InvalidAlgorithmParameterException { ECParameterSpec ecSpec = null; if (params instanceof ECParameterSpec) { ecSpec = ECUtil.getECParameterSpec(null, (ECParameterSpec)params); if (ecSpec == null) { throw new InvalidAlgorithmParameterException( "Unsupported curve: " + params); } } else if (params instanceof ECGenParameterSpec) { String name = ((ECGenParameterSpec)params).getName(); ecSpec = ECUtil.getECParameterSpec(null, name); if (ecSpec == null) { throw new InvalidAlgorithmParameterException( "Unknown curve name: " + name); } } else { throw new InvalidAlgorithmParameterException( "ECParameterSpec or ECGenParameterSpec required for EC"); } // Not all known curves are supported by the native implementation ensureCurveIsSupported(ecSpec); this.params = ecSpec; this.keySize = ((ECParameterSpec)this.params).getCurve().getField().getFieldSize(); this.random = random; } private static void ensureCurveIsSupported(ECParameterSpec ecSpec) throws InvalidAlgorithmParameterException { AlgorithmParameters ecParams = ECUtil.getECParameters(null); byte[] encodedParams; try { ecParams.init(ecSpec); encodedParams = ecParams.getEncoded(); } catch (InvalidParameterSpecException ex) { throw new InvalidAlgorithmParameterException( "Unsupported curve: " + ecSpec.toString()); } catch (IOException ex) { throw new RuntimeException(ex); } if (!isCurveSupported(encodedParams)) { throw new InvalidAlgorithmParameterException( "Unsupported curve: " + ecParams.toString()); } } // generate the keypair. See JCA doc @Override public KeyPair generateKeyPair() { byte[] encodedParams = ECUtil.encodeECParameterSpec(null, (ECParameterSpec)params); // seed is twice the key size (in bytes) plus 1 byte[] seed = new byte[(((keySize + 7) >> 3) + 1) * 2]; if (random == null) { random = JCAUtil.getSecureRandom(); } random.nextBytes(seed); try { Object[] keyBytes = generateECKeyPair(keySize, encodedParams, seed); // The 'params' object supplied above is equivalent to the native // one so there is no need to fetch it. // keyBytes[0] is the encoding of the native private key BigInteger s = new BigInteger(1, (byte[])keyBytes[0]); PrivateKey privateKey = new ECPrivateKeyImpl(s, (ECParameterSpec)params); // keyBytes[1] is the encoding of the native public key ECPoint w = ECUtil.decodePoint((byte[])keyBytes[1], ((ECParameterSpec)params).getCurve()); PublicKey publicKey = new ECPublicKeyImpl(w, (ECParameterSpec)params); return new KeyPair(publicKey, privateKey); } catch (Exception e) { throw new ProviderException(e); } } private void checkKeySize(int keySize) throws InvalidParameterException { if (keySize < KEY_SIZE_MIN) { throw new InvalidParameterException ("Key size must be at least " + KEY_SIZE_MIN + " bits"); } if (keySize > KEY_SIZE_MAX) { throw new InvalidParameterException ("Key size must be at most " + KEY_SIZE_MAX + " bits"); } this.keySize = keySize; } /** * Checks whether the curve in the encoded parameters is supported by the * native implementation. * * @param encodedParams encoded parameters in the same form accepted * by generateECKeyPair * @return true if and only if generateECKeyPair will succeed for * the supplied parameters */ private static native boolean isCurveSupported(byte[] encodedParams); /* * Generates the keypair and returns a 2-element array of encoding bytes. * The first one is for the private key, the second for the public key. */ private static native Object[] generateECKeyPair(int keySize, byte[] encodedParams, byte[] seed) throws GeneralSecurityException; }