/*

 * Copyright (c) 2016, 2018, Oracle and/or its affiliates. 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.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

import java.io.BufferedOutputStream;

import java.io.BufferedReader;

import java.io.ByteArrayInputStream;

import java.io.ByteArrayOutputStream;

import java.io.File;

import java.io.FileOutputStream;

import java.io.IOException;

import java.io.InputStreamReader;

import java.io.PrintStream;

import java.text.DateFormat;

import java.text.ParseException;

import java.text.SimpleDateFormat;

import java.util.ArrayList;

import java.util.Calendar;

import java.util.Date;

import java.util.List;

import java.util.Locale;

final public class MacCertificate {

    private final String certificate;

    private final boolean verbose;

    public MacCertificate(String certificate) {

        this.certificate = certificate;

        this.verbose = false;

    }

    public MacCertificate(String certificate, boolean verbose) {

        this.certificate = certificate;

        this.verbose = verbose;

    }

    public boolean isValid() {

        return verifyCertificate(this.certificate, verbose);

    }

    private static File findCertificate(String certificate, boolean verbose) {

        File result = null;

        List<String> args = new ArrayList<>();

        args.add("security");

        args.add("find-certificate");

        args.add("-c");

        args.add(certificate);

        args.add("-a");

        args.add("-p");

        try (ByteArrayOutputStream baos = new ByteArrayOutputStream();

                PrintStream ps = new PrintStream(baos)) {

            ProcessBuilder security = new ProcessBuilder(args);

            IOUtils.exec(security, verbose, false, ps);

            File output = File.createTempFile("tempfile", ".tmp");

            PrintStream p = new PrintStream(

                    new BufferedOutputStream(

                            new FileOutputStream(output, true)));

            BufferedReader bfReader = new BufferedReader(

                    new InputStreamReader(

                            new ByteArrayInputStream(baos.toByteArray())));

            String line = null;

            while((line = bfReader.readLine()) != null){

                p.println(line);

            }

            p.close();

            result = output;

        }

        catch (IOException ignored) {}

        return result;

    }

    private static Date findCertificateDate(String filename, boolean verbose) {

        Date result = null;

        List<String> args = new ArrayList<>();

        args.add("/usr/bin/openssl");

        args.add("x509");

        args.add("-noout");

        args.add("-enddate");

        args.add("-in");

        args.add(filename);

        try (ByteArrayOutputStream baos = new ByteArrayOutputStream();

                PrintStream ps = new PrintStream(baos)) {

            ProcessBuilder security = new ProcessBuilder(args);

            IOUtils.exec(security, verbose, false, ps);

            String output = baos.toString();

            output = output.substring(output.indexOf("=") + 1);

            DateFormat df = new SimpleDateFormat(

                    "MMM dd kk:mm:ss yyyy z", Locale.ENGLISH);

            result = df.parse(output);

        } catch (IOException | ParseException ex) {

            Log.debug(ex);

        }

        return result;

    }

    private static boolean verifyCertificate(

            String certificate, boolean verbose) {

        boolean result = false;

        try {

            File file = null;

            Date certificateDate = null;

            try {

                file = findCertificate(certificate, verbose);

                if (file != null) {

                    certificateDate = findCertificateDate(

                            file.getCanonicalPath(), verbose);

                }

            }

            finally {

                if (file != null) {

                    file.delete();

                }

            }

            if (certificateDate != null) {

                Calendar c = Calendar.getInstance();

                Date today = c.getTime();

                if (certificateDate.after(today)) {

                    result = true;

                }

            }

        }

        catch (IOException ignored) {}

        return result;

    }

}