yacy_search_server/source/de/anomic/tools/crypt.java

// crypt.java 
// -------------------------------------
// (C) by Michael Peter Christen; mc@anomic.de
// first published on http://www.anomic.de
// Frankfurt, Germany, 2004
// last major change: 13.05.2004
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 2 of the License, or
// (at your option) any later version.
//
// This program 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 for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
//
// Using this software in any meaning (reading, learning, copying, compiling,
// running) means that you agree that the Author(s) is (are) not responsible
// for cost, loss of data or any harm that may be caused directly or indirectly
// by usage of this softare or this documentation. The usage of this software
// is on your own risk. The installation and usage (starting/running) of this
// software may allow other people or application to access your computer and
// any attached devices and is highly dependent on the configuration of the
// software which must be done by the user of the software; the author(s) is
// (are) also not responsible for proper configuration and usage of the
// software, even if provoked by documentation provided together with
// the software.
//
// Any changes to this file according to the GPL as documented in the file
// gpl.txt aside this file in the shipment you received can be done to the
// lines that follows this copyright notice here, but changes must not be
// done inside the copyright notive above. A re-distribution must contain
// the intact and unchanged copyright notice.
// Contributions and changes to the program code must be marked as such.

package de.anomic.tools;

import java.text.SimpleDateFormat;
import java.util.Locale;
import java.util.Random;

import de.anomic.server.serverCodings;

public class crypt {

    // --------------------------------------------------------
    // Section: random salt generation
    // --------------------------------------------------------

    private static long saltcounter = 0;
    private static Random saltrandom = new Random(System.currentTimeMillis());

    public static String randomSalt() {
	// generate robust 48-bit random number
	long salt =
	    (saltrandom.nextLong() & 0XffffffffffffL) + 
	    (System.currentTimeMillis() & 0XffffffffffffL) +
	    ((1001 * saltcounter) & 0XffffffffffffL);
	saltcounter++;
	// we generate 48-bit salt values, that are represented as 8-character b64-encoded strings
	return serverCodings.standardCoder.encodeBase64Long(salt & 0XffffffffffffL, 8);
    }

    // --------------------------------------------------------
    // Section: PBE + PublicKey based on passwords encryption
    // --------------------------------------------------------

    public static final String vDATE = "20030925";
    public static final String copyright = "[ 'crypt' v" + vDATE + " by Michael Christen / www.anomic.de ]";
    public static final String magicString = "crypt|anomic.de|0"; // magic identifier inside every '.crypt' - file
    public static final SimpleDateFormat dateFormatter = new SimpleDateFormat("yyyyMMddHHmmssSSS", Locale.ENGLISH);

    String cryptMethod; // one of ["TripleDES", "Blowfish", "DESede", "DES"]
    private static final String defaultMethod = "PBEWithMD5AndDES"; //"DES";
    
    public crypt(String pbe) {
	// this is possible, but not recommended
	this(pbe, (pbe + "XXXXXXXX").substring(0, 8));
    }

    public crypt(String pbe, String salt) {
	this(pbe, salt, defaultMethod);
    }
    private crypt(String pbe, String salt, String method) {
	// a Password-Based Encryption. The SecretKey is created on the fly
	    if (salt.length() > 8) salt = salt.substring(0,8);
	    if (salt.length() < 8) salt = (salt + "XXXXXXXX").substring(0,8);
	            
	    // Create a cipher and initialize it for encrypting end decrypting
	    cryptMethod = method;
    }

    // --------------------------------------------------------
    // Section: simple Codings
    // --------------------------------------------------------

    public static String simpleEncode(String content) {
	return simpleEncode(content, null, 'b');
    }

    public static String simpleEncode(String content, String key) {
	return simpleEncode(content, key, 'b');
    }

    public static String simpleEncode(String content, String key, char method) {
	if (key == null) key = "NULL";
	if (method == 'p') return "p|" + content;
	if (method == 'b') return "b|" + serverCodings.enhancedCoder.encodeBase64String(content);
	if (method == 'z') return "z|" + serverCodings.enhancedCoder.encodeBase64(gzip.gzipString(content));
	return null;
    }

    public static String simpleDecode(String encoded, String key) {
	if ((encoded == null) || (encoded.length() < 3)) return null;
	if (encoded.charAt(1) != '|') return encoded; // not encoded
	char method = encoded.charAt(0);
	encoded = encoded.substring(2);
	if (method == 'p') return encoded;
	if (method == 'b') return serverCodings.enhancedCoder.decodeBase64String(encoded);
	if (method == 'z') return gzip.gunzipString(serverCodings.enhancedCoder.decodeBase64(encoded));
	return null;
    }

}