/*

 * Copyright (c) 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.

 *

 * 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

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 * questions.

 */

/*

 * @test

 * @bug 8201867

 * @summary Kerberos keytabs with holes in certain places are parsed incorrectly

 * @modules java.security.jgss/sun.security.krb5

 *          java.security.jgss/sun.security.krb5.internal.ktab

 * @run main/othervm BufferBoundary

 */

import sun.security.krb5.PrincipalName;

import sun.security.krb5.internal.ktab.KeyTab;

import sun.security.krb5.internal.ktab.KeyTabEntry;

import sun.security.krb5.internal.ktab.KeyTabInputStream;

import sun.security.krb5.internal.ktab.KeyTabOutputStream;

import java.io.FileInputStream;

import java.io.FileOutputStream;

import java.io.IOException;

import java.nio.file.Files;

import java.nio.file.Paths;

import java.util.List;

public class BufferBoundary {

    public static void main(String[] args) throws Exception {

        // We force using one etype so the output is determined

        Files.write(Paths.get("krb5.conf"), List.of(

                "[libdefaults]",

                "default_tkt_enctypes = aes128-cts"

        ));

        System.setProperty("java.security.krb5.conf", "krb5.conf");

        KeyTab kt = KeyTab.create("ktab");

        int num = 0;

        while (true) {

            num++;

            PrincipalName pn = new PrincipalName(

                    String.format("user%03d@REALM", num));

            kt.addEntry(pn, "password".toCharArray(), num, true);

            int length = 2;

            for (KeyTabEntry e : kt.getEntries()) {

                length += e.entryLength() + 4;

            }

            // Create enough big keytab

            if (length > 8400) {

                break;

            }

        }

        kt.save();

        int count = 0;

        boolean written = false;

        try (KeyTabInputStream kin

                     = new KeyTabInputStream(new FileInputStream("ktab"));

                KeyTabOutputStream kout

                        = new KeyTabOutputStream(new FileOutputStream("ktab2"))) {

            kout.write(kin.readNBytes(2)); // version

            count += 2;

            while (true) {

                int len;

                try {

                    len = kin.read(4);

                } catch (IOException e) {

                    break; // reach end

                }

                count += 4;

                byte[] data = kin.readNBytes(len);

                count += len;

                if (count < 8192 || written) {

                    kout.write32(len);

                    kout.write(data);

                } else {

                    // Create a hole on the 8192 boundary

                    kout.write32(-len);

                    kout.write(new byte[len]);

                    written = true;

                }

            }

        }

        kt = KeyTab.getInstance("ktab2");

        if (!kt.isValid()) {

            throw new Exception("Should be valid");

        }

        if (kt.getEntries().length != num - 1) {

            throw new Exception("Should have " + (num - 1) + " entries");

        }

    }

}