/*

 * 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.

 */

/*

 *  (C) Copyright IBM Corp. 1999 All Rights Reserved.

 *  Copyright 1997 The Open Group Research Institute.  All rights reserved.

 */

package sun.security.krb5.internal.tools;

import sun.security.krb5.*;

import sun.security.krb5.internal.*;

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

import sun.security.krb5.KrbCryptoException;

import java.lang.RuntimeException;

import java.io.IOException;

import java.io.BufferedReader;

import java.io.InputStreamReader;

import java.io.FileOutputStream;

import java.io.File;

import java.util.Arrays;

/**

 * This class can execute as a command-line tool to help the user manage

 * entires in the key table.

 * Available functions include list/add/update/delete service key(s).

 *

 * @author Yanni Zhang

 * @author Ram Marti

 */

public class Ktab {

    // KeyTabAdmin admin;

    KeyTab table;

    char action;

    String name;   // name and directory of key table

    String principal;

    char[] password = null;

    /**

     * The main program that can be invoked at command line.

     * <br>Usage: ktab <options>

     * <br>available options to Ktab:

     * <ul>

     * <li><b>-l</b>  list the keytab name and entries

     * <li><b>-a</b>  &lt;<i>principal name</i>&gt;

     * (&lt;<i>password</i>&gt;)  add an entry to the keytab.

     * The entry is added only to the keytab. No changes are made to the

     * Kerberos database.

     * <li><b>-d</b>  &lt;<i>principal name</i>&gt;

     * delete an entry from the keytab

     * The entry is deleted only from the keytab. No changes are made to the

     * Kerberos database.

     * <li><b>-k</b>  &lt;<i>keytab name</i> &gt;

     * specify keytab name and path with prefix FILE:

     * <li><b>-help</b> display instructions.

     */

    public static void main(String[] args) {

        Ktab ktab = new Ktab();

        if ((args.length == 1) && (args[0].equalsIgnoreCase("-help"))) {

            ktab.printHelp();

            System.exit(0);

        } else if ((args == null) || (args.length == 0)) {

            ktab.action = 'l';

        } else {

            ktab.processArgs(args);

        }

        try {

            if (ktab.name == null) {

                //  ktab.admin = new KeyTabAdmin();    // use the default keytab.

                ktab.table = KeyTab.getInstance();

                if (ktab.table == null) {

                    if (ktab.action == 'a') {

                        ktab.table = KeyTab.create();

                    } else {

                        System.out.println("No default key table exists.");

                        System.exit(-1);

                    }

                }

            } else {

                if ((ktab.action != 'a') &&

                    !(new File(ktab.name)).exists()) {

                    System.out.println("Key table " +

                                ktab.name + " does not exist.");

                    System.exit(-1);

                } else {

                    ktab.table = KeyTab.getInstance(ktab.name);

                }

                if (ktab.table == null) {

                    if (ktab.action == 'a') {

                        ktab.table = KeyTab.create(ktab.name);

                    } else {

                        System.out.println("The format of key table " +

                                ktab.name + " is incorrect.");

                        System.exit(-1);

                    }

                }

            }

        } catch (RealmException e) {

            System.err.println("Error loading key table.");

            System.exit(-1);

        } catch (IOException e) {

            System.err.println("Error loading key table.");

            System.exit(-1);

        }

        switch (ktab.action) {

        case 'l':

            ktab.listKt();

            break;

        case 'a':

            ktab.addEntry();

            break;

        case 'd':

            ktab.deleteEntry();

            break;

        default:

            ktab.printHelp();

            System.exit(-1);

        }

    }

    /**

     * Parses the command line arguments.

     */

    void processArgs(String[] args) {

        Character arg = null;

        for (int i = 0; i < args.length; i++) {

            if ((args[i].length() == 2) && (args[i].startsWith("-"))) {

                arg = new Character(args[i].charAt(1));

            } else {

                printHelp();

                System.exit(-1);

            }

            switch (arg.charValue()) {

            case 'l':

            case 'L':

                action = 'l';    // list keytab location, name and entries

                break;

            case 'a':

            case 'A':

                action = 'a'; // add a new entry to keytab.

                i++;

                if ((i < args.length) && (!args[i].startsWith("-"))) {

                    principal = args[i];

                } else {

                    System.out.println("Please specify the principal name"+

                                       " after -a option.");

                    printHelp();

                    System.exit(-1);

                }

                if ((i + 1 < args.length) &&

                    (!args[i + 1].startsWith("-"))) {

                    password = args[i + 1].toCharArray();

                    i++;

                } else {

                    password = null; // prompt user for password later.

                }

                break;

            case 'd':

            case 'D':

                action = 'd'; // delete an entry.

                i++;

                if ((i < args.length) && (!args[i].startsWith("-"))) {

                    principal = args[i];

                } else {

                    System.out.println("Please specify the principal" +

                                       "name of the entry you want to " +

                                       " delete after -d option.");

                    printHelp();

                    System.exit(-1);

                }

                break;

            case 'k':

            case 'K':

                i++;

                if ((i < args.length) && (!args[i].startsWith("-"))) {

                    if (args[i].length() >= 5 &&

                        args[i].substring(0, 5).equalsIgnoreCase("FILE:")) {

                        name = args[i].substring(5);

                    } else

                        name = args[i];

                } else {

                    System.out.println("Please specify the keytab "+

                                       "file name and location " +

                                       "after -k option");

                    printHelp();

                    System.exit(-1);

                }

                break;

            default:

                printHelp();

                System.exit(-1);

            }

        }

    }

    /**

     * Adds a service key to key table. If the specified key table does not

     * exist, the program will automatically generate

     * a new key table.

     */

    void addEntry() {

        PrincipalName pname = null;

        try {

            pname = new PrincipalName(principal);

            if (pname.getRealm() == null) {

                pname.setRealm(Config.getInstance().getDefaultRealm());

            }

        } catch (KrbException e) {

            System.err.println("Failed to add " + principal +

                               " to keytab.");

            e.printStackTrace();

            System.exit(-1);

        }

        if (password == null) {

            try {

                BufferedReader cis =

                    new BufferedReader(new InputStreamReader(System.in));

                System.out.print("Password for " + pname.toString() + ":");

                System.out.flush();

                password = cis.readLine().toCharArray();

            } catch (IOException e) {

                System.err.println("Failed to read the password.");

                e.printStackTrace();

                System.exit(-1);

            }

        }

        try {

            // admin.addEntry(pname, password);

            table.addEntry(pname, password);

            Arrays.fill(password, '0');  // clear password

            // admin.save();

            table.save();

            System.out.println("Done!");

            System.out.println("Service key for " + principal +

                               " is saved in " + table.tabName());

        } catch (KrbException e) {

            System.err.println("Failed to add " + principal + " to keytab.");

            e.printStackTrace();

            System.exit(-1);

        } catch (IOException e) {

            System.err.println("Failed to save new entry.");

            e.printStackTrace();

            System.exit(-1);

        }

    }

    /**

     * Lists key table name and entries in it.

     */

    void listKt() {

        int version;

        String principal;

        // System.out.println("Keytab name: " + admin.getKeyTabName());

        System.out.println("Keytab name: " + table.tabName());

        // KeyTabEntry[] entries = admin.getEntries();

        KeyTabEntry[] entries = table.getEntries();

        if ((entries != null) && (entries.length > 0)) {

            System.out.println("KVNO    Principal");

            for (int i = 0; i < entries.length; i++) {

                version = entries[i].getKey().getKeyVersionNumber().intValue();

                principal = entries[i].getService().toString();

                if (i == 0) {

                    StringBuffer separator = new StringBuffer();

                    for (int j = 0; j < 9 + principal.length(); j++) {

                        separator.append("-");

                    }

                    System.out.println(separator.toString());

                }

                System.out.println("  " + version + "     " + principal);

            }

        } else {

            System.out.println("0 entry.");

        }

    }

    /**

     * Deletes an entry from the key table.

     */

    void deleteEntry() {

        PrincipalName pname = null;

        try {

            pname = new PrincipalName(principal);

            if (pname.getRealm() == null) {

                pname.setRealm(Config.getInstance().getDefaultRealm());

            }

            String answer;

            BufferedReader cis =

                new BufferedReader(new InputStreamReader(System.in));

            System.out.print("Are you sure you want to "+

                             " delete service key for " + pname.toString() +

                             " in " + table.tabName() + "?(Y/N) :");

            System.out.flush();

            answer = cis.readLine();

            if (answer.equalsIgnoreCase("Y") ||

                answer.equalsIgnoreCase("Yes"));

            else {

                // no error, the user did not want to delete the entry

                System.exit(0);

            }

        } catch (KrbException e) {

            System.err.println("Error occured while deleting the entry. "+

                               "Deletion failed.");

            e.printStackTrace();

            System.exit(-1);

        } catch (IOException e) {

            System.err.println("Error occured while deleting the entry. "+

                               " Deletion failed.");

            e.printStackTrace();

            System.exit(-1);

        }

        // admin.deleteEntry(pname);

        table.deleteEntry(pname);

        try {

            table.save();

        } catch (IOException e) {

            System.err.println("Error occurs while saving the keytab." +

                               "Deletion fails.");

            e.printStackTrace();

            System.exit(-1);

        }

        System.out.println("Done!");

    }

    /**

     * Prints out the help information.

     */

    void printHelp() {

        System.out.println("\nUsage: ktab " +

                           "<options>");

        System.out.println("available options to Ktab:");

        System.out.println("-l\t\t\t\tlist the keytab name and entries");

        System.out.println("-a <principal name> (<password>)add an entry " +

                           "to the keytab");

        System.out.println("-d <principal name>\t\tdelete an entry from "+

                           "the keytab");

        System.out.println("-k <keytab name>\t\tspecify keytab name and "+

                           " path with prefix FILE:");

    }

}