rijndael_properties.java

用JAVA编写的rijndael工具

//$Id: Rijndael_Properties.java,v 1.1 2001/05/21 02:24:30 jis Exp $
//
// $Log: Rijndael_Properties.java,v $
// Revision 1.1  2001/05/21 02:24:30  jis
// First version
//
// Revision 1.0  1998/04/07  raif
// + original version.
//
// $Endlog$
/*
 * Copyright (c) 1997, 1998 Systemics Ltd on behalf of
 * the Cryptix Development Team. All rights reserved.
 */
package mit.Rijndael;

import java.io.InputStream;
import java.io.PrintStream;
import java.io.PrintWriter;
import java.util.Enumeration;
import java.util.Properties;

/**
 * This class acts as a central repository for an algorithm specific properties.
 * It reads an (algorithm).properties file containing algorithm- specific
 * properties. When using the AES-Kit, this (algorithm).properties file is
 * located in the (algorithm).jar file produced by the "jarit" batch/ script
 * command.
 * <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: 1.1 $</b>
 * 
 * @author David Hopwood
 * @author Jill Baker
 * @author Raif S. Naffah
 */
public class Rijndael_Properties // implicit no-argument constructor
{
	// Constants and variables with relevant static code
	// ...........................................................................

	static final boolean GLOBAL_DEBUG = false;

	static final String ALGORITHM = "Rijndael";

	static final double VERSION = 0.1;

	static final String FULL_NAME = ALGORITHM + " ver. " + VERSION;

	static final String NAME = "Rijndael_Properties";

	static final Properties properties = new Properties();

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

	static {
		if (GLOBAL_DEBUG)
			System.err.println(">>> " + NAME + ": Looking for " + ALGORITHM
					+ " properties");
		String it = ALGORITHM + ".properties";
		InputStream is = Rijndael_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 e = properties.propertyNames();
		while (e.hasMoreElements()) {
			key = (String) e.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;
	}
}