Java tutorial
/* * The MIT License * * Copyright (c) 2015, CloudBees, Inc. * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to deal * in the Software without restriction, including without limitation the rights * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell * copies of the Software, and to permit persons to whom the Software is * furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in * all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN * THE SOFTWARE. */ package jenkins.security; import org.apache.commons.codec.binary.Base64; import java.io.IOException; import java.security.GeneralSecurityException; import java.security.KeyFactory; import java.security.KeyPair; import java.security.KeyPairGenerator; import java.security.PrivateKey; import java.security.SecureRandom; import java.security.interfaces.RSAPrivateCrtKey; import java.security.interfaces.RSAPrivateKey; import java.security.interfaces.RSAPublicKey; import java.security.spec.PKCS8EncodedKeySpec; import java.security.spec.RSAPublicKeySpec; /** * RSA public/private key pair as {@link ConfidentialKey}. * * <p> * As per the design principle of {@link ConfidentialKey}, not exposing {@link PrivateKey} directly. * Define subtypes for different use cases. * * @author Kohsuke Kawaguchi */ public abstract class RSAConfidentialKey extends ConfidentialKey { private RSAPrivateKey priv; private RSAPublicKey pub; public RSAConfidentialKey(String id) { super(id); } public RSAConfidentialKey(Class owner, String shortName) { this(owner.getName() + '.' + shortName); } /** * Obtains the private key (lazily.) * <p> * This method is not publicly exposed as per the design principle of {@link ConfidentialKey}. * Instead of exposing private key, define methods that use them in specific way, such as * {@link RSADigitalSignatureConfidentialKey}. * * @throws Error * If key cannot be loaded for some reasons, we fail. */ protected synchronized RSAPrivateKey getPrivateKey() { try { if (priv == null) { byte[] payload = load(); if (payload == null) { KeyPairGenerator gen = KeyPairGenerator.getInstance("RSA"); gen.initialize(2048, new SecureRandom()); // going beyond 2048 requires crypto extension KeyPair keys = gen.generateKeyPair(); priv = (RSAPrivateKey) keys.getPrivate(); pub = (RSAPublicKey) keys.getPublic(); store(priv.getEncoded()); } else { KeyFactory keyFactory = KeyFactory.getInstance("RSA"); priv = (RSAPrivateKey) keyFactory.generatePrivate(new PKCS8EncodedKeySpec(payload)); RSAPrivateCrtKey pks = (RSAPrivateCrtKey) priv; pub = (RSAPublicKey) keyFactory .generatePublic(new RSAPublicKeySpec(pks.getModulus(), pks.getPublicExponent())); } } return priv; } catch (IOException e) { throw new Error("Failed to load the key: " + getId(), e); } catch (GeneralSecurityException e) { throw new Error("Failed to load the key: " + getId(), e); } } public RSAPublicKey getPublicKey() { getPrivateKey(); return pub; } /** * Gets base64-encoded public key. */ public String getEncodedPublicKey() { return new String(Base64.encodeBase64(getPublicKey().getEncoded())); } }