001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *   http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 *
017 */
018
019package org.apache.commons.net.util;
020
021import java.io.File;
022import java.io.FileInputStream;
023import java.io.IOException;
024import java.net.Socket;
025import java.security.GeneralSecurityException;
026import java.security.KeyStore;
027import java.security.KeyStoreException;
028import java.security.Principal;
029import java.security.PrivateKey;
030import java.security.cert.Certificate;
031import java.security.cert.X509Certificate;
032import java.util.Enumeration;
033
034import javax.net.ssl.KeyManager;
035import javax.net.ssl.X509ExtendedKeyManager;
036
037import org.apache.commons.net.io.Util;
038
039/**
040 * General KeyManager utilities
041 * <p>
042 * How to use with a client certificate:
043 * <pre>
044 * KeyManager km = KeyManagerUtils.createClientKeyManager("JKS",
045 *     "/path/to/privatekeystore.jks","storepassword",
046 *     "privatekeyalias", "keypassword");
047 * FTPSClient cl = new FTPSClient();
048 * cl.setKeyManager(km);
049 * cl.connect(...);
050 * </pre>
051 * If using the default store type and the key password is the same as the
052 * store password, these parameters can be omitted. <br/>
053 * If the desired key is the first or only key in the keystore, the keyAlias parameter
054 * can be omitted, in which case the code becomes:
055 * <pre>
056 * KeyManager km = KeyManagerUtils.createClientKeyManager(
057 *     "/path/to/privatekeystore.jks","storepassword");
058 * FTPSClient cl = new FTPSClient();
059 * cl.setKeyManager(km);
060 * cl.connect(...);
061 * </pre>
062 *
063 * @since 3.0
064 */
065public final class KeyManagerUtils {
066
067    private static final String DEFAULT_STORE_TYPE = KeyStore.getDefaultType();
068
069    private KeyManagerUtils(){
070        // Not instantiable
071    }
072
073    /**
074     * Create a client key manager which returns a particular key.
075     * Does not handle server keys.
076     *
077     * @param ks the keystore to use
078     * @param keyAlias the alias of the key to use, may be {@code null} in which case the first key entry alias is used
079     * @param keyPass the password of the key to use
080     * @return the customised KeyManager
081     */
082    public static KeyManager createClientKeyManager(KeyStore ks, String keyAlias, String keyPass)
083        throws GeneralSecurityException
084    {
085        ClientKeyStore cks = new ClientKeyStore(ks, keyAlias != null ? keyAlias : findAlias(ks), keyPass);
086        return new X509KeyManager(cks);
087    }
088
089    /**
090     * Create a client key manager which returns a particular key.
091     * Does not handle server keys.
092     *
093     * @param storeType the type of the keyStore, e.g. "JKS"
094     * @param storePath the path to the keyStore
095     * @param storePass the keyStore password
096     * @param keyAlias the alias of the key to use, may be {@code null} in which case the first key entry alias is used
097     * @param keyPass the password of the key to use
098     * @return the customised KeyManager
099     */
100    public static KeyManager createClientKeyManager(String storeType, File storePath, String storePass, String keyAlias, String keyPass)
101        throws IOException, GeneralSecurityException
102    {
103        KeyStore ks = loadStore(storeType, storePath, storePass);
104        return createClientKeyManager(ks, keyAlias, keyPass);
105    }
106
107    /**
108     * Create a client key manager which returns a particular key.
109     * Does not handle server keys.
110     * Uses the default store type and assumes the key password is the same as the store password
111     *
112     * @param storePath the path to the keyStore
113     * @param storePass the keyStore password
114     * @param keyAlias the alias of the key to use, may be {@code null} in which case the first key entry alias is used
115     * @return the customised KeyManager
116     */
117    public static KeyManager createClientKeyManager(File storePath, String storePass, String keyAlias)
118        throws IOException, GeneralSecurityException
119    {
120        return createClientKeyManager(DEFAULT_STORE_TYPE, storePath, storePass, keyAlias, storePass);
121    }
122
123    /**
124     * Create a client key manager which returns a particular key.
125     * Does not handle server keys.
126     * Uses the default store type and assumes the key password is the same as the store password.
127     * The key alias is found by searching the keystore for the first private key entry
128     *
129     * @param storePath the path to the keyStore
130     * @param storePass the keyStore password
131     * @return the customised KeyManager
132     */
133    public static KeyManager createClientKeyManager(File storePath, String storePass)
134        throws IOException, GeneralSecurityException
135    {
136        return createClientKeyManager(DEFAULT_STORE_TYPE, storePath, storePass, null, storePass);
137    }
138
139    private static KeyStore loadStore(String storeType, File storePath, String storePass)
140        throws KeyStoreException,  IOException, GeneralSecurityException {
141        KeyStore ks = KeyStore.getInstance(storeType);
142        FileInputStream stream = null;
143        try {
144            stream = new FileInputStream(storePath);
145            ks.load(stream, storePass.toCharArray());
146        } finally {
147            Util.closeQuietly(stream);
148        }
149        return ks;
150    }
151
152    private static String findAlias(KeyStore ks) throws KeyStoreException {
153        Enumeration<String> e = ks.aliases();
154        while(e.hasMoreElements()) {
155            String entry = e.nextElement();
156            if (ks.isKeyEntry(entry)) {
157                return entry;
158            }
159        }
160        throw new KeyStoreException("Cannot find a private key entry");
161    }
162
163    private static class ClientKeyStore {
164
165        private final X509Certificate[] certChain;
166        private final PrivateKey key;
167        private final String keyAlias;
168
169        ClientKeyStore(KeyStore ks, String keyAlias, String keyPass) throws GeneralSecurityException
170        {
171            this.keyAlias = keyAlias;
172            this.key = (PrivateKey) ks.getKey(this.keyAlias, keyPass.toCharArray());
173            Certificate[] certs = ks.getCertificateChain(this.keyAlias);
174            X509Certificate[] X509certs = new X509Certificate[certs.length];
175            for (int i=0; i < certs.length; i++) {
176                X509certs[i] = (X509Certificate) certs[i];
177            }
178            this.certChain = X509certs;
179        }
180
181        final X509Certificate[] getCertificateChain() {
182            return this.certChain;
183        }
184
185        final PrivateKey getPrivateKey() {
186            return this.key;
187        }
188
189        final String getAlias() {
190            return this.keyAlias;
191        }
192    }
193
194    private static class X509KeyManager extends X509ExtendedKeyManager  {
195
196        private final ClientKeyStore keyStore;
197
198        X509KeyManager(final ClientKeyStore keyStore) {
199            this.keyStore = keyStore;
200        }
201
202        // Call sequence: 1
203        public String chooseClientAlias(String[] keyType, Principal[] issuers,
204                Socket socket) {
205            return keyStore.getAlias();
206        }
207
208        // Call sequence: 2
209        public X509Certificate[] getCertificateChain(String alias) {
210            return keyStore.getCertificateChain();
211        }
212
213        public String[] getClientAliases(String keyType, Principal[] issuers) {
214            return new String[]{ keyStore.getAlias()};
215        }
216
217        // Call sequence: 3
218        public PrivateKey getPrivateKey(String alias) {
219            return keyStore.getPrivateKey();
220        }
221
222        public String[] getServerAliases(String keyType, Principal[] issuers) {
223            return null;
224        }
225
226        public String chooseServerAlias(String keyType, Principal[] issuers, Socket socket) {
227            return null;
228        }
229
230    }
231
232}