commons-net.jar is the bytecode of Apache Commons Net library, which implements the client side of many basic Internet protocols.

Apache Commons Net Source Code files are provided in the binary packge (commons-net-3.8.0-bin.zip). You can download it at Apache Commons Net Website.

The source code of commons-net-3.8.0.jar is provided below:

⏎ org/apache/commons/net/util/KeyManagerUtils.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */

package org.apache.commons.net.util;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.net.Socket;
import java.security.GeneralSecurityException;
import java.security.KeyStore;
import java.security.KeyStoreException;
import java.security.Principal;
import java.security.PrivateKey;
import java.security.cert.Certificate;
import java.security.cert.X509Certificate;
import java.util.Enumeration;

import javax.net.ssl.KeyManager;
import javax.net.ssl.X509ExtendedKeyManager;

import org.apache.commons.net.io.Util;

/**
 * General KeyManager utilities
 * <p>
 * How to use with a client certificate:
 * <pre>
 * KeyManager km = KeyManagerUtils.createClientKeyManager("JKS",
 *     "/path/to/privatekeystore.jks","storepassword",
 *     "privatekeyalias", "keypassword");
 * FTPSClient cl = new FTPSClient();
 * cl.setKeyManager(km);
 * cl.connect(...);
 * </pre>
 * If using the default store type and the key password is the same as the
 * store password, these parameters can be omitted. <br>
 * If the desired key is the first or only key in the keystore, the keyAlias parameter
 * can be omitted, in which case the code becomes:
 * <pre>
 * KeyManager km = KeyManagerUtils.createClientKeyManager(
 *     "/path/to/privatekeystore.jks","storepassword");
 * FTPSClient cl = new FTPSClient();
 * cl.setKeyManager(km);
 * cl.connect(...);
 * </pre>
 *
 * @since 3.0
 */
public final class KeyManagerUtils {

    private static final String DEFAULT_STORE_TYPE = KeyStore.getDefaultType();

    private KeyManagerUtils(){
        // Not instantiable
    }

    /**
     * Create a client key manager which returns a particular key.
     * Does not handle server keys.
     *
     * @param ks the keystore to use
     * @param keyAlias the alias of the key to use, may be {@code null} in which case the first key entry alias is used
     * @param keyPass the password of the key to use
     * @return the customised KeyManager
     * @throws GeneralSecurityException if there is a problem creating the keystore
     */
    public static KeyManager createClientKeyManager(final KeyStore ks, final String keyAlias, final String keyPass)
        throws GeneralSecurityException
    {
        final ClientKeyStore cks = new ClientKeyStore(ks, keyAlias != null ? keyAlias : findAlias(ks), keyPass);
        return new X509KeyManager(cks);
    }

    /**
     * Create a client key manager which returns a particular key.
     * Does not handle server keys.
     *
     * @param storeType the type of the keyStore, e.g. "JKS"
     * @param storePath the path to the keyStore
     * @param storePass the keyStore password
     * @param keyAlias the alias of the key to use, may be {@code null} in which case the first key entry alias is used
     * @param keyPass the password of the key to use
     * @return the customised KeyManager
     * @throws GeneralSecurityException if there is a problem creating the keystore
     * @throws IOException if there is a problem creating the keystore
     */
    public static KeyManager createClientKeyManager(
            final String storeType, final File storePath, final String storePass, final String keyAlias, final String keyPass)
        throws IOException, GeneralSecurityException
    {
        final KeyStore ks = loadStore(storeType, storePath, storePass);
        return createClientKeyManager(ks, keyAlias, keyPass);
    }

    /**
     * Create a client key manager which returns a particular key.
     * Does not handle server keys.
     * Uses the default store type and assumes the key password is the same as the store password
     *
     * @param storePath the path to the keyStore
     * @param storePass the keyStore password
     * @param keyAlias the alias of the key to use, may be {@code null} in which case the first key entry alias is used
     * @return the customised KeyManager
     * @throws IOException if there is a problem creating the keystore
     * @throws GeneralSecurityException if there is a problem creating the keystore
     */
    public static KeyManager createClientKeyManager(final File storePath, final String storePass, final String keyAlias)
        throws IOException, GeneralSecurityException
    {
        return createClientKeyManager(DEFAULT_STORE_TYPE, storePath, storePass, keyAlias, storePass);
    }

    /**
     * Create a client key manager which returns a particular key.
     * Does not handle server keys.
     * Uses the default store type and assumes the key password is the same as the store password.
     * The key alias is found by searching the keystore for the first private key entry
     *
     * @param storePath the path to the keyStore
     * @param storePass the keyStore password
     * @return the customised KeyManager
     * @throws IOException if there is a problem creating the keystore
     * @throws GeneralSecurityException if there is a problem creating the keystore
     */
    public static KeyManager createClientKeyManager(final File storePath, final String storePass)
        throws IOException, GeneralSecurityException
    {
        return createClientKeyManager(DEFAULT_STORE_TYPE, storePath, storePass, null, storePass);
    }

    private static KeyStore loadStore(final String storeType, final File storePath, final String storePass)
        throws KeyStoreException,  IOException, GeneralSecurityException {
        final KeyStore ks = KeyStore.getInstance(storeType);
        FileInputStream stream = null;
        try {
            stream = new FileInputStream(storePath);
            ks.load(stream, storePass.toCharArray());
        } finally {
            Util.closeQuietly(stream);
        }
        return ks;
    }

    private static String findAlias(final KeyStore ks) throws KeyStoreException {
        final Enumeration<String> e = ks.aliases();
        while(e.hasMoreElements()) {
            final String entry = e.nextElement();
            if (ks.isKeyEntry(entry)) {
                return entry;
            }
        }
        throw new KeyStoreException("Cannot find a private key entry");
    }

    private static class ClientKeyStore {

        private final X509Certificate[] certChain;
        private final PrivateKey key;
        private final String keyAlias;

        ClientKeyStore(final KeyStore ks, final String keyAlias, final String keyPass) throws GeneralSecurityException
        {
            this.keyAlias = keyAlias;
            this.key = (PrivateKey) ks.getKey(this.keyAlias, keyPass.toCharArray());
            final Certificate[] certs = ks.getCertificateChain(this.keyAlias);
            final X509Certificate[] X509certs = new X509Certificate[certs.length];
            for (int i=0; i < certs.length; i++) {
                X509certs[i] = (X509Certificate) certs[i];
            }
            this.certChain = X509certs;
        }

        final X509Certificate[] getCertificateChain() {
            return this.certChain;
        }

        final PrivateKey getPrivateKey() {
            return this.key;
        }

        final String getAlias() {
            return this.keyAlias;
        }
    }

    private static class X509KeyManager extends X509ExtendedKeyManager  {

        private final ClientKeyStore keyStore;

        X509KeyManager(final ClientKeyStore keyStore) {
            this.keyStore = keyStore;
        }

        // Call sequence: 1
        @Override
        public String chooseClientAlias(final String[] keyType, final Principal[] issuers,
                final Socket socket) {
            return keyStore.getAlias();
        }

        // Call sequence: 2
        @Override
        public X509Certificate[] getCertificateChain(final String alias) {
            return keyStore.getCertificateChain();
        }

        @Override
        public String[] getClientAliases(final String keyType, final Principal[] issuers) {
            return new String[]{ keyStore.getAlias()};
        }

        // Call sequence: 3
        @Override
        public PrivateKey getPrivateKey(final String alias) {
            return keyStore.getPrivateKey();
        }

        @Override
        public String[] getServerAliases(final String keyType, final Principal[] issuers) {
            return null;
        }

        @Override
        public String chooseServerAlias(final String keyType, final Principal[] issuers, final Socket socket) {
            return null;
        }

    }

}

⏎ org/apache/commons/net/util/KeyManagerUtils.java

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File name: commons-net-3.8.0-sources.jar
File size: 437325 bytes
Release date: 2020-01-22
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