001/*
002 * nimbus-jose-jwt
003 *
004 * Copyright 2012-2016, Connect2id Ltd and contributors.
005 *
006 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use
007 * this file except in compliance with the License. You may obtain a copy of the
008 * License at
009 *
010 *    http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software distributed
013 * under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
014 * CONDITIONS OF ANY KIND, either express or implied. See the License for the
015 * specific language governing permissions and limitations under the License.
016 */
017
018package com.nimbusds.jose.jwk.gen;
019
020
021import com.nimbusds.jose.JOSEException;
022import com.nimbusds.jose.jwk.Curve;
023import com.nimbusds.jose.jwk.ECKey;
024
025import java.security.InvalidAlgorithmParameterException;
026import java.security.KeyPair;
027import java.security.KeyPairGenerator;
028import java.security.NoSuchAlgorithmException;
029import java.security.interfaces.ECPublicKey;
030import java.security.spec.ECParameterSpec;
031import java.util.Objects;
032
033
034/**
035 * Elliptic Curve (EC) JSON Web Key (JWK) generator.
036 *
037 * <p>Supported curves:
038 *
039 * <ul>
040 *     <li>{@link Curve#P_256 P-256}
041 *     <li>{@link Curve#SECP256K1 secp256k1}
042 *     <li>{@link Curve#P_384 P-384}
043 *     <li>{@link Curve#P_521 P-512}
044 * </ul>
045 *
046 * @author Vladimir Dzhuvinov
047 * @author Justin Cranford
048 * @version 2024-12-15
049 */
050public class ECKeyGenerator extends JWKGenerator<ECKey> {
051        
052        
053        /**
054         * The curve.
055         */
056        private final Curve crv;
057        
058        
059        /**
060         * Creates a new EC JWK generator.
061         *
062         * @param crv The curve. Must not be {@code null}.
063         */
064        public ECKeyGenerator(final Curve crv) {
065                this.crv = Objects.requireNonNull(crv);
066        }
067        
068        
069        @Override
070        public ECKey generate()
071                throws JOSEException  {
072                
073                ECParameterSpec ecSpec = crv.toECParameterSpec();
074                
075                KeyPairGenerator generator;
076                try {
077                        if (keyStore != null) {
078                                // For PKCS#11
079                                generator = KeyPairGenerator.getInstance("EC", keyStore.getProvider());
080                        } else if (provider != null) {
081                                generator = KeyPairGenerator.getInstance("EC", provider);
082                        } else {
083                                generator = KeyPairGenerator.getInstance("EC");
084                        }
085                        if (secureRandom != null) {
086                                generator.initialize(ecSpec, secureRandom);
087                        } else {
088                                // The default random gen
089                                generator.initialize(ecSpec);
090                        }
091                } catch (NoSuchAlgorithmException | InvalidAlgorithmParameterException e) {
092                        throw new JOSEException(e.getMessage(), e);
093                }
094                
095                KeyPair kp = generator.generateKeyPair();
096                
097                ECKey.Builder builder = new ECKey.Builder(crv, (ECPublicKey) kp.getPublic())
098                        .privateKey(kp.getPrivate())
099                        .keyUse(use)
100                        .keyOperations(ops)
101                        .algorithm(alg)
102                        .expirationTime(exp)
103                        .notBeforeTime(nbf)
104                        .issueTime(iat)
105                        .keyStore(keyStore);
106                
107                if (tprKid) {
108                        builder.keyIDFromThumbprint();
109                } else {
110                        builder.keyID(kid);
111                }
112                
113                return builder.build();
114        }
115}