serpent_properties.java

密码serpent算法源代码, 该算法是AES候选算法之一

// $Id: $
//
// $Log: $
// Revision 1.0  1998/04/10  raif
// + start of history.
//
// $Endlog$
/*
 * Copyright (c) 1997, 1998 Systemics Ltd on behalf of
 * the Cryptix Development Team. All rights reserved.
 */
package Serpent;

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.InputStream;
import java.io.IOException;
import java.io.PrintWriter;
import java.io.PrintStream;
import java.util.Enumeration;
import java.util.Properties;

/**
 * This class acts as a central repository for an algorithm specific
 * properties.<p>
 *
 * <b>Copyright</b> &copy; 1997, 1998
 * <a href="http://www.systemics.com/">Systemics Ltd</a> on behalf of the
 * <a href="http://www.systemics.com/docs/cryptix/">Cryptix Development Team</a>.
 * <br>All rights reserved.<p>
 *
 * <b>$Revision: $</b>
 * @author  David Hopwood
 * @author  Jill Baker
 * @author  Raif S. Naffah
 */
public class Serpent_Properties // implicit no-argument constructor
{
// Constants and variables with relevant static code
//...........................................................................

    static final boolean GLOBAL_DEBUG = false;

    static final String ALGORITHM = "Serpent";
    static final double VERSION = 0.1;
    static final String FULL_NAME = ALGORITHM + " ver. " + VERSION;
    static final String NAME = "Serpent_Properties";

    /**
     * The (algorithm).properties file containing algorithm-specific
     * properties. Only the 'lib' folder/directory in (java.home) is
     * searched for this properties file.
     */
    static final Properties properties = new Properties();

    /** Default properties in case .properties file was not found. */
    private static final String[][] DEFAULT_PROPERTIES = {
        {"Trace.Serpent_Algorithm",       "true"},
        {"Debug.Level.*",                 "1"},
        {"Debug.Level.Serpent_Algorithm", "9"},
    };

    static {
if (GLOBAL_DEBUG) System.err.println(">>> " + NAME + ": Looking for " + ALGORITHM + " properties");
        String it = ALGORITHM + ".properties";
        InputStream is = Serpent_Properties.class.getResourceAsStream(it);
        boolean ok = is != null;
        if (ok)
            try {
                properties.load(is);
                is.close();
if (GLOBAL_DEBUG) System.err.println(">>> " + NAME + ": Properties file loaded OK...");
            } catch (Exception x) {
                ok = false;
            }
        if (!ok) {
if (GLOBAL_DEBUG) System.err.println(">>> " + NAME + ": WARNING: Unable to load \"" + it + "\" from CLASSPATH.");
if (GLOBAL_DEBUG) System.err.println(">>> " + NAME + ":          Will use default values instead...");
            int n = DEFAULT_PROPERTIES.length;
            for (int i = 0; i < n; i++)
                properties.put(
                    DEFAULT_PROPERTIES[i][0], DEFAULT_PROPERTIES[i][1]);
if (GLOBAL_DEBUG) System.err.println(">>> " + NAME + ": Default properties now set...");
        }
    }


// Properties methods (excluding load and save, which are deliberately not
// supported).
//...........................................................................

    /** Get the value of a property for this algorithm. */
    public static String getProperty (String key) {
        return properties.getProperty(key);
    }

    /**
     * Get the value of a property for this algorithm, or return
     * <i>value</i> if the property was not set.
     */
    public static String getProperty (String key, String value) {
        return properties.getProperty(key, value);
    }

    /** List algorithm properties to the PrintStream <i>out</i>. */
    public static void list (PrintStream out) {
        list(new PrintWriter(out, true));
    }

    /** List algorithm properties to the PrintWriter <i>out</i>. */
    public static void list (PrintWriter out) {
        out.println("#");
        out.println("# ----- Begin "+ALGORITHM+" properties -----");
        out.println("#");
        String key, value;
        Enumeration enum = properties.propertyNames();
        while (enum.hasMoreElements()) {
            key = (String) enum.nextElement();
            value = getProperty(key);
            out.println(key + " = " + value);
        }
        out.println("#");
        out.println("# ----- End "+ALGORITHM+" properties -----");
    }

//    public synchronized void load(InputStream in) throws IOException {}

    public static Enumeration propertyNames() {
        return properties.propertyNames();
    }

//    public void save (OutputStream os, String comment) {}


// Developer support: Tracing and debugging enquiry methods (package-private)
//...........................................................................
    
    /**
     * Return true if tracing is requested for a given class.<p>
     *
     * User indicates this by setting the tracing <code>boolean</code>
     * property for <i>label</i> in the <code>(algorithm).properties</code>
     * file. The property's key is "<code>Trace.<i>label</i></code>".<p>
     *
     * @param label  The name of a class.
     * @return True iff a boolean true value is set for a property with
     *      the key <code>Trace.<i>label</i></code>.
     */
    static boolean isTraceable (String label) {
        String s = getProperty("Trace." + label);
        if (s == null)
            return false;
        return new Boolean(s).booleanValue();
    }

    /**
     * Return the debug level for a given class.<p>
     *
     * User indicates this by setting the numeric property with key
     * "<code>Debug.Level.<i>label</i></code>".<p>
     *
     * If this property is not set, "<code>Debug.Level.*</code>" is looked up
     * next. If neither property is set, or if the first property found is
     * not a valid decimal integer, then this method returns 0.
     *
     * @param label  The name of a class.
     * @return  The required debugging level for the designated class.
     */
    static int getLevel(String label) {
        String s = getProperty("Debug.Level." + label);
        if (s == null) {
            s = getProperty("Debug.Level.*");
            if (s == null)
                return 0;
        }
        try {
            return Integer.parseInt(s);
        } catch (NumberFormatException e) {
            return 0;
        }
    }

    /**
     * Return the PrintWriter to which tracing and debugging output is to
     * be sent.<p>
     *
     * User indicates this by setting the property with key <code>Output</code>
     * to the literal <code>out</code> or <code>err</code>.<p>
     *
     * By default or if the set value is not allowed, <code>System.err</code>
     * will be used.
     */
    static PrintWriter getOutput() {
        PrintWriter pw;
        String name = getProperty("Output");
        if (name != null && name.equals("out"))
            pw = new PrintWriter(System.out, true);
        else
            pw = new PrintWriter(System.err, true);
        return pw;
    }
}