/*
 * Copyright 2004-2006 Sun Microsystems, Inc.  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.  Sun designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
 * CA 95054 USA or visit www.sun.com if you need additional information or
 * have any questions.
 */

package sun.security.util;

import java.io.*;
import java.net.*;
import java.security.*;
import java.util.Arrays;

import sun.net.www.ParseUtil;


/**
 * A utility class for getting a KeyStore instance from policy information.
 * In addition, a supporting getInputStream method.
 *
 */
public class PolicyUtil {

    // standard PKCS11 KeyStore type
    private static final String P11KEYSTORE = "PKCS11";

    // reserved word
    private static final String NONE = "NONE";

    /*
     * Fast path reading from file urls in order to avoid calling
     * FileURLConnection.connect() which can be quite slow the first time
     * it is called. We really should clean up FileURLConnection so that
     * this is not a problem but in the meantime this fix helps reduce
     * start up time noticeably for the new launcher. -- DAC
     */
    public static InputStream getInputStream(URL url) throws IOException {
        if ("file".equals(url.getProtocol())) {
            String path = url.getFile().replace('/', File.separatorChar);
            path = ParseUtil.decode(path);
            return new FileInputStream(path);
        } else {
            return url.openStream();
        }
    }

    /**
     * this is intended for use by policytool and the policy parser to
     * instantiate a KeyStore from the information in the GUI/policy file
     */
    public static KeyStore getKeyStore
                (URL policyUrl,                 // URL of policy file
                String keyStoreName,            // input: keyStore URL
                String keyStoreType,            // input: keyStore type
                String keyStoreProvider,        // input: keyStore provider
                String storePassURL,            // input: keyStore password
                Debug debug)
        throws KeyStoreException, MalformedURLException, IOException,
                NoSuchProviderException, NoSuchAlgorithmException,
                java.security.cert.CertificateException {

        if (keyStoreName == null) {
            throw new IllegalArgumentException("null KeyStore name");
        }

        char[] keyStorePassword = null;
        try {
            KeyStore ks;
            if (keyStoreType == null) {
                keyStoreType = KeyStore.getDefaultType();
            }

            if (P11KEYSTORE.equalsIgnoreCase(keyStoreType) &&
                !NONE.equals(keyStoreName)) {
                throw new IllegalArgumentException
                        ("Invalid value (" +
                        keyStoreName +
                        ") for keystore URL.  If the keystore type is \"" +
                        P11KEYSTORE +
                        "\", the keystore url must be \"" +
                        NONE +
                        "\"");
            }

            if (keyStoreProvider != null) {
                ks = KeyStore.getInstance(keyStoreType, keyStoreProvider);
            } else {
                ks = KeyStore.getInstance(keyStoreType);
            }

            if (storePassURL != null) {
                URL passURL;
                try {
                    passURL = new URL(storePassURL);
                    // absolute URL
                } catch (MalformedURLException e) {
                    // relative URL
                    if (policyUrl == null) {
                        throw e;
                    }
                    passURL = new URL(policyUrl, storePassURL);
                }

                if (debug != null) {
                    debug.println("reading password"+passURL);
                }

                InputStream in = null;
                try {
                    in = passURL.openStream();
                    keyStorePassword = Password.readPassword(in);
                } finally {
                    if (in != null) {
                        in.close();
                    }
                }
            }

            if (NONE.equals(keyStoreName)) {
                ks.load(null, keyStorePassword);
                return ks;
            } else {
                /*
                 * location of keystore is specified as absolute URL in policy
                 * file, or is relative to URL of policy file
                 */
                URL keyStoreUrl = null;
                try {
                    keyStoreUrl = new URL(keyStoreName);
                    // absolute URL
                } catch (MalformedURLException e) {
                    // relative URL
                    if (policyUrl == null) {
                        throw e;
                    }
                    keyStoreUrl = new URL(policyUrl, keyStoreName);
                }

                if (debug != null) {
                    debug.println("reading keystore"+keyStoreUrl);
                }

                InputStream inStream = null;
                try {
                    inStream =
                        new BufferedInputStream(getInputStream(keyStoreUrl));
                    ks.load(inStream, keyStorePassword);
                } finally {
                    inStream.close();
                }
                return ks;
            }
        } finally {
            if (keyStorePassword != null) {
                Arrays.fill(keyStorePassword, ' ');
            }
        }
    }
}