server/filter/KeyManager.java

/* 
 * i-scream central monitoring system
 * http://www.i-scream.org.uk
 * Copyright (C) 2000-2002 i-scream
 * 
 * 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.
 */

//---PACKAGE DECLARATION---
package uk.org.iscream.cms.server.filter;

//---IMPORTS---
import uk.org.iscream.cms.util.*;
import uk.org.iscream.cms.server.core.*;
import uk.org.iscream.cms.server.componentmanager.*;
import java.util.Random;
import java.util.HashMap;

/**
 * Acts as a store and checking mechanism for host keys.
 *
 * @author  $Author: tdb $
 * @version $Id: KeyManager.java,v 1.4 2002/05/21 16:47:17 tdb Exp $
 */
public class KeyManager {

//---FINAL ATTRIBUTES---

    /**
     * The current CVS revision of this class
     */
    public final String REVISION = "$Revision: 1.4 $";
    
    /**
     * The set of characters to be used for our keys
     */
    private final char[] KEYSET = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789".toCharArray();
    
    /**
     * Default key length
     */
    public static final int DEFKEYLEN = 15;
    
//---STATIC METHODS---

    /**
     * Return a reference to the single class.
     * Construct it if it does not already exist, otherwise just return the reference.
     */
    public synchronized static KeyManager getInstance() {
        if (_instance == null){
            _instance = new KeyManager();
        }
        return _instance;
    }

//---CONSTRUCTORS---
    
    /**
     * Private constructor to avoid external construction.
     */
    private KeyManager() {
        try {
            String keylen = ConfigurationProxy.getInstance().getProperty("Filter." + FilterMain.NAME, "Filter.KeyLength");
            _keylen = Integer.parseInt(keylen);
        }
        catch (PropertyNotFoundException e) {
            _keylen = DEFKEYLEN;
            _logger.write(toString(), Logger.WARNING, "No key length found, using default of " +_keylen+ " : " + e);
        }
        catch (NumberFormatException e) {
            _keylen = DEFKEYLEN;
            _logger.write(toString(), Logger.WARNING, "Malformed key length found, using default of " +_keylen+ " : " + e);
        }
    }

//---PUBLIC METHODS---
    
    /**
     * Add or replace a key.
     *
     * @param host the hostname to add a key for
     * @param key the key to add
     */
    public synchronized void addKey(String host, String key) {
        _keys.put(host, key);
    }
    
    /**
     * Check if a given key is currently valid.
     * Will respond negatively if the key doesn't match,
     * or if no key is found (and EnforceHostAuth is on).
     *
     * @param host the hostname to check the key for
     * @param key the key to check
     * @return whether the check was successful
     */
    public synchronized boolean checkKey(String host, String key) {
        Object o = _keys.get(host);
        if(o != null) {
            // if our key isn't null, we want to make
            // sure it matches that given
            String ourKey = (String) o;
            return ourKey.equals(key);
        }
        else {
            // default to enforcing host auth
            boolean enforceHostAuth = true;
            try {
                // try to get see what's in the config
                String enforce = ConfigurationProxy.getInstance().getProperty("Filter." + FilterMain.NAME, "Filter.EnforceHostAuth");
                enforceHostAuth = (Integer.parseInt(enforce) == 1);
            }
            catch(PropertyNotFoundException e) {
                // if it's not set, not enforced
                _logger.write(toString(), Logger.WARNING, "EnforceHostAuth property not found: " + e);
                enforceHostAuth = false;
            }
            catch(NumberFormatException e) {
                // if it's not a number, not enforced
                _logger.write(toString(), Logger.WARNING, "EnforceHostAuth property malformed: " + e);
                enforceHostAuth = false;
            }
            // if enforceHostAuth is true we want to fail the check
            // and vice-versa
            return !enforceHostAuth;
        }
    }
    
    /**
     * Generate a random key with length KEYLEN.
     *
     * @return a random key as a String
     */
    public String genKey() {
        Random r = new Random();
        StringBuffer s = new StringBuffer();
        for(int i=0; i < _keylen; i++) {
            s.append(KEYSET[r.nextInt(KEYSET.length)]);
        }
        return s.toString();
    }
    
    /**
     * Overrides the {@link java.lang.Object#toString() Object.toString()}
     * method to provide clean logging (every class should have this).
     *
     * This uses the uk.org.iscream.cms.util.NameFormat class
     * to format the toString()
     *
     * @return the name of this class and its CVS revision
     */
    public String toString() {
        return FormatName.getName(
            _name,
            getClass().getName(),
            REVISION);
    }

//---PRIVATE METHODS---
    
//---ACCESSOR/MUTATOR METHODS---

//---ATTRIBUTES---
    
    /**
     * This holds the current keys for
     * the hosts we're authenticating
     */
    private HashMap _keys = new HashMap();

    /**
     * The length of our keys
     */
    private int _keylen;
    
    /**
     * This holds a reference to the
     * system logger that is being used.
     */
    private Logger _logger = ReferenceManager.getInstance().getLogger();
    
    /**
     * This is the friendly identifier of the
     * component this class is running in.
     * eg, a Filter may be called "filter1",
     * If this class does not have an owning
     * component,  a name from the configuration
     * can be placed here.  This name could also
     * be changed to null for utility classes.
     */
    private String _name = FilterMain.NAME;

//---STATIC ATTRIBUTES---

    /**
     * A reference to the single instance of this class
     */
    private static KeyManager _instance;

}
Revision:	1.5
Committed:	Wed Feb 5 16:43:47 2003 UTC (21 years, 3 months ago) by tdb
Branch:	MAIN
Changes since 1.4:	+4 -4 lines
Log Message:	Changed the server to use the external util package. Quite a minor change, but does affect a lot of files.
#	User	Rev	Content
1	tdb	1.3	/*
2			* i-scream central monitoring system
3	tdb	1.4	* http://www.i-scream.org.uk
4	tdb	1.3	* Copyright (C) 2000-2002 i-scream
5			*
6			* This program is free software; you can redistribute it and/or
7			* modify it under the terms of the GNU General Public License
8			* as published by the Free Software Foundation; either version 2
9			* of the License, or (at your option) any later version.
10			*
11			* This program is distributed in the hope that it will be useful,
12			* but WITHOUT ANY WARRANTY; without even the implied warranty of
13			* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14			* GNU General Public License for more details.
15			*
16			* You should have received a copy of the GNU General Public License
17			* along with this program; if not, write to the Free Software
18			* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
19			*/
20
21	tdb	1.1	//---PACKAGE DECLARATION---
22			package uk.org.iscream.cms.server.filter;
23
24			//---IMPORTS---
25	tdb	1.5	import uk.org.iscream.cms.util.*;
26	tdb	1.1	import uk.org.iscream.cms.server.core.*;
27			import uk.org.iscream.cms.server.componentmanager.*;
28			import java.util.Random;
29			import java.util.HashMap;
30
31			/**
32			* Acts as a store and checking mechanism for host keys.
33			*
34	tdb	1.2	* @author $Author: tdb $
35	tdb	1.5	* @version $Id: KeyManager.java,v 1.4 2002/05/21 16:47:17 tdb Exp $
36	tdb	1.1	*/
37			public class KeyManager {
38
39			//---FINAL ATTRIBUTES---
40
41			/**
42			* The current CVS revision of this class
43			*/
44	tdb	1.5	public final String REVISION = "$Revision: 1.4 $";
45	tdb	1.1
46			/**
47			* The set of characters to be used for our keys
48			*/
49			private final char[] KEYSET = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789".toCharArray();
50
51			/**
52	tdb	1.2	* Default key length
53	tdb	1.1	*/
54	tdb	1.2	public static final int DEFKEYLEN = 15;
55	tdb	1.1
56			//---STATIC METHODS---
57
58			/**
59			* Return a reference to the single class.
60			* Construct it if it does not already exist, otherwise just return the reference.
61			*/
62			public synchronized static KeyManager getInstance() {
63			if (_instance == null){
64			_instance = new KeyManager();
65			}
66			return _instance;
67			}
68
69			//---CONSTRUCTORS---
70
71			/**
72			* Private constructor to avoid external construction.
73			*/
74			private KeyManager() {
75	tdb	1.2	try {
76			String keylen = ConfigurationProxy.getInstance().getProperty("Filter." + FilterMain.NAME, "Filter.KeyLength");
77			_keylen = Integer.parseInt(keylen);
78			}
79			catch (PropertyNotFoundException e) {
80			_keylen = DEFKEYLEN;
81			_logger.write(toString(), Logger.WARNING, "No key length found, using default of " +_keylen+ " : " + e);
82			}
83			catch (NumberFormatException e) {
84			_keylen = DEFKEYLEN;
85			_logger.write(toString(), Logger.WARNING, "Malformed key length found, using default of " +_keylen+ " : " + e);
86			}
87	tdb	1.1	}
88
89			//---PUBLIC METHODS---
90
91			/**
92			* Add or replace a key.
93			*
94			* @param host the hostname to add a key for
95			* @param key the key to add
96			*/
97			public synchronized void addKey(String host, String key) {
98			_keys.put(host, key);
99			}
100
101			/**
102			* Check if a given key is currently valid.
103			* Will respond negatively if the key doesn't match,
104			* or if no key is found (and EnforceHostAuth is on).
105			*
106			* @param host the hostname to check the key for
107			* @param key the key to check
108			* @return whether the check was successful
109			*/
110			public synchronized boolean checkKey(String host, String key) {
111			Object o = _keys.get(host);
112			if(o != null) {
113			// if our key isn't null, we want to make
114			// sure it matches that given
115			String ourKey = (String) o;
116			return ourKey.equals(key);
117			}
118			else {
119			// default to enforcing host auth
120			boolean enforceHostAuth = true;
121			try {
122			// try to get see what's in the config
123			String enforce = ConfigurationProxy.getInstance().getProperty("Filter." + FilterMain.NAME, "Filter.EnforceHostAuth");
124			enforceHostAuth = (Integer.parseInt(enforce) == 1);
125			}
126			catch(PropertyNotFoundException e) {
127			// if it's not set, not enforced
128			_logger.write(toString(), Logger.WARNING, "EnforceHostAuth property not found: " + e);
129			enforceHostAuth = false;
130			}
131			catch(NumberFormatException e) {
132			// if it's not a number, not enforced
133			_logger.write(toString(), Logger.WARNING, "EnforceHostAuth property malformed: " + e);
134			enforceHostAuth = false;
135			}
136			// if enforceHostAuth is true we want to fail the check
137			// and vice-versa
138			return !enforceHostAuth;
139			}
140			}
141
142			/**
143			* Generate a random key with length KEYLEN.
144			*
145			* @return a random key as a String
146			*/
147			public String genKey() {
148			Random r = new Random();
149			StringBuffer s = new StringBuffer();
150	tdb	1.2	for(int i=0; i < _keylen; i++) {
151	tdb	1.1	s.append(KEYSET[r.nextInt(KEYSET.length)]);
152			}
153			return s.toString();
154			}
155
156			/**
157			* Overrides the {@link java.lang.Object#toString() Object.toString()}
158			* method to provide clean logging (every class should have this).
159			*
160	tdb	1.5	* This uses the uk.org.iscream.cms.util.NameFormat class
161	tdb	1.1	* to format the toString()
162			*
163			* @return the name of this class and its CVS revision
164			*/
165			public String toString() {
166			return FormatName.getName(
167			_name,
168			getClass().getName(),
169			REVISION);
170			}
171
172			//---PRIVATE METHODS---
173
174			//---ACCESSOR/MUTATOR METHODS---
175
176			//---ATTRIBUTES---
177
178			/**
179			* This holds the current keys for
180			* the hosts we're authenticating
181			*/
182			private HashMap _keys = new HashMap();
183	tdb	1.2
184			/**
185			* The length of our keys
186			*/
187			private int _keylen;
188	tdb	1.1
189			/**
190			* This holds a reference to the
191			* system logger that is being used.
192			*/
193			private Logger _logger = ReferenceManager.getInstance().getLogger();
194
195			/**
196			* This is the friendly identifier of the
197			* component this class is running in.
198			* eg, a Filter may be called "filter1",
199			* If this class does not have an owning
200			* component, a name from the configuration
201			* can be placed here. This name could also
202			* be changed to null for utility classes.
203			*/
204			private String _name = FilterMain.NAME;
205
206			//---STATIC ATTRIBUTES---
207
208			/**
209			* A reference to the single instance of this class
210			*/
211			private static KeyManager _instance;
212
213			}