/*

 * Copyright (c) 1998, 2011, 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.

 */

package sun.security.util;

import java.math.BigInteger;

import java.util.regex.Pattern;

import java.util.regex.Matcher;

import java.util.Locale;

/**

 * A utility class for debuging.

 *

 * @author Roland Schemers

 */

public class Debug {

    private String prefix;

    private static String args;

    static {

        args = java.security.AccessController.doPrivileged

                (new sun.security.action.GetPropertyAction

                ("java.security.debug"));

        String args2 = java.security.AccessController.doPrivileged

                (new sun.security.action.GetPropertyAction

                ("java.security.auth.debug"));

        if (args == null) {

            args = args2;

        } else {

            if (args2 != null)

               args = args + "," + args2;

        }

        if (args != null) {

            args = marshal(args);

            if (args.equals("help")) {

                Help();

            }

        }

    }

    public static void Help()

    {

        System.err.println();

        System.err.println("all           turn on all debugging");

        System.err.println("access        print all checkPermission results");

        System.err.println("combiner      SubjectDomainCombiner debugging");

        System.err.println("gssloginconfig");

        System.err.println("configfile    JAAS ConfigFile loading");

        System.err.println("configparser  JAAS ConfigFile parsing");

        System.err.println("              GSS LoginConfigImpl debugging");

        System.err.println("jar           jar verification");

        System.err.println("logincontext  login context results");

        System.err.println("policy        loading and granting");

        System.err.println("provider      security provider debugging");

        System.err.println("scl           permissions SecureClassLoader assigns");

        System.err.println("ts            timestamping");

        System.err.println();

        System.err.println("The following can be used with access:");

        System.err.println();

        System.err.println("stack         include stack trace");

        System.err.println("domain        dump all domains in context");

        System.err.println("failure       before throwing exception, dump stack");

        System.err.println("              and domain that didn't have permission");

        System.err.println();

        System.err.println("The following can be used with stack and domain:");

        System.err.println();

        System.err.println("permission=<classname>");

        System.err.println("              only dump output if specified permission");

        System.err.println("              is being checked");

        System.err.println("codebase=<URL>");

        System.err.println("              only dump output if specified codebase");

        System.err.println("              is being checked");

        System.err.println();

        System.err.println("Note: Separate multiple options with a comma");

        System.exit(0);

    }

    /**

     * Get a Debug object corresponding to whether or not the given

     * option is set. Set the prefix to be the same as option.

     */

    public static Debug getInstance(String option)

    {

        return getInstance(option, option);

    }

    /**

     * Get a Debug object corresponding to whether or not the given

     * option is set. Set the prefix to be prefix.

     */

    public static Debug getInstance(String option, String prefix)

    {

        if (isOn(option)) {

            Debug d = new Debug();

            d.prefix = prefix;

            return d;

        } else {

            return null;

        }

    }

    /**

     * True if the system property "security.debug" contains the

     * string "option".

     */

    public static boolean isOn(String option)

    {

        if (args == null)

            return false;

        else {

            if (args.indexOf("all") != -1)

                return true;

            else

                return (args.indexOf(option) != -1);

        }

    }

    /**

     * print a message to stderr that is prefixed with the prefix

     * created from the call to getInstance.

     */

    public void println(String message)

    {

        System.err.println(prefix + ": "+message);

    }

    /**

     * print a blank line to stderr that is prefixed with the prefix.

     */

    public void println()

    {

        System.err.println(prefix + ":");

    }

    /**

     * print a message to stderr that is prefixed with the prefix.

     */

    public static void println(String prefix, String message)

    {

        System.err.println(prefix + ": "+message);

    }

    /**

     * return a hexadecimal printed representation of the specified

     * BigInteger object. the value is formatted to fit on lines of

     * at least 75 characters, with embedded newlines. Words are

     * separated for readability, with eight words (32 bytes) per line.

     */

    public static String toHexString(BigInteger b) {

        String hexValue = b.toString(16);

        StringBuffer buf = new StringBuffer(hexValue.length()*2);

        if (hexValue.startsWith("-")) {

            buf.append("   -");

            hexValue = hexValue.substring(1);

        } else {

            buf.append("    ");     // four spaces

        }

        if ((hexValue.length()%2) != 0) {

            // add back the leading 0

            hexValue = "0" + hexValue;

        }

        int i=0;

        while (i < hexValue.length()) {

            // one byte at a time

            buf.append(hexValue.substring(i, i+2));

            i+=2;

            if (i!= hexValue.length()) {

                if ((i%64) == 0) {

                    buf.append("\n    ");     // line after eight words

                } else if (i%8 == 0) {

                    buf.append(" ");     // space between words

                }

            }

        }

        return buf.toString();

    }

    /**

     * change a string into lower case except permission classes and URLs.

     */

    private static String marshal(String args) {

        if (args != null) {

            StringBuffer target = new StringBuffer();

            StringBuffer source = new StringBuffer(args);

            // obtain the "permission=<classname>" options

            // the syntax of classname: IDENTIFIER.IDENTIFIER

            // the regular express to match a class name:

            // "[a-zA-Z_$][a-zA-Z0-9_$]*([.][a-zA-Z_$][a-zA-Z0-9_$]*)*"

            String keyReg = "[Pp][Ee][Rr][Mm][Ii][Ss][Ss][Ii][Oo][Nn]=";

            String keyStr = "permission=";

            String reg = keyReg +

                "[a-zA-Z_$][a-zA-Z0-9_$]*([.][a-zA-Z_$][a-zA-Z0-9_$]*)*";

            Pattern pattern = Pattern.compile(reg);

            Matcher matcher = pattern.matcher(source);

            StringBuffer left = new StringBuffer();

            while (matcher.find()) {

                String matched = matcher.group();

                target.append(matched.replaceFirst(keyReg, keyStr));

                target.append("  ");

                // delete the matched sequence

                matcher.appendReplacement(left, "");

            }

            matcher.appendTail(left);

            source = left;

            // obtain the "codebase=<URL>" options

            // the syntax of URL is too flexible, and here assumes that the

            // URL contains no space, comma(','), and semicolon(';'). That

            // also means those characters also could be used as separator

            // after codebase option.

            // However, the assumption is incorrect in some special situation

            // when the URL contains comma or semicolon

            keyReg = "[Cc][Oo][Dd][Ee][Bb][Aa][Ss][Ee]=";

            keyStr = "codebase=";

            reg = keyReg + "[^, ;]*";

            pattern = Pattern.compile(reg);

            matcher = pattern.matcher(source);

            left = new StringBuffer();

            while (matcher.find()) {

                String matched = matcher.group();

                target.append(matched.replaceFirst(keyReg, keyStr));

                target.append("  ");

                // delete the matched sequence

                matcher.appendReplacement(left, "");

            }

            matcher.appendTail(left);

            source = left;

            // convert the rest to lower-case characters

            target.append(source.toString().toLowerCase(Locale.ENGLISH));

            return target.toString();

        }

        return null;

    }

    private final static char[] hexDigits = "0123456789abcdef".toCharArray();

    public static String toString(byte[] b) {

        if (b == null) {

            return "(null)";

        }

        StringBuilder sb = new StringBuilder(b.length * 3);

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

            int k = b[i] & 0xff;

            if (i != 0) {

                sb.append(':');

            }

            sb.append(hexDigits[k >>> 4]);

            sb.append(hexDigits[k & 0xf]);

        }

        return sb.toString();

    }

}