001/*
002 *  Licensed to the Apache Software Foundation (ASF) under one
003 *  or more contributor license agreements.  See the NOTICE file
004 *  distributed with this work for additional information
005 *  regarding copyright ownership.  The ASF licenses this file
006 *  to you under the Apache License, Version 2.0 (the
007 *  "License"); you may not use this file except in compliance
008 *  with the License.  You may obtain a copy of the License at
009 *  
010 *    http://www.apache.org/licenses/LICENSE-2.0
011 *  
012 *  Unless required by applicable law or agreed to in writing,
013 *  software distributed under the License is distributed on an
014 *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015 *  KIND, either express or implied.  See the License for the
016 *  specific language governing permissions and limitations
017 *  under the License. 
018 *  
019 */
020package org.apache.directory.server.kerberos.changepwd.service;
021
022import java.net.InetAddress;
023import java.net.UnknownHostException;
024import java.nio.ByteBuffer;
025
026import javax.security.auth.kerberos.KerberosPrincipal;
027
028import org.apache.directory.api.asn1.ber.Asn1Decoder;
029import org.apache.directory.api.util.Network;
030import org.apache.directory.api.util.Strings;
031import org.apache.directory.server.i18n.I18n;
032import org.apache.directory.server.kerberos.ChangePasswordConfig;
033import org.apache.directory.server.kerberos.changepwd.exceptions.ChangePasswdErrorType;
034import org.apache.directory.server.kerberos.changepwd.exceptions.ChangePasswordException;
035import org.apache.directory.server.kerberos.changepwd.messages.AbstractPasswordMessage;
036import org.apache.directory.server.kerberos.changepwd.messages.ChangePasswordReply;
037import org.apache.directory.server.kerberos.changepwd.messages.ChangePasswordRequest;
038import org.apache.directory.server.kerberos.shared.crypto.encryption.CipherTextHandler;
039import org.apache.directory.server.kerberos.shared.crypto.encryption.KeyUsage;
040import org.apache.directory.server.kerberos.shared.replay.ReplayCache;
041import org.apache.directory.server.kerberos.shared.store.PrincipalStore;
042import org.apache.directory.server.kerberos.shared.store.PrincipalStoreEntry;
043import org.apache.directory.shared.kerberos.KerberosUtils;
044import org.apache.directory.shared.kerberos.codec.KerberosDecoder;
045import org.apache.directory.shared.kerberos.codec.changePwdData.ChangePasswdDataContainer;
046import org.apache.directory.shared.kerberos.codec.types.EncryptionType;
047import org.apache.directory.shared.kerberos.codec.types.PrincipalNameType;
048import org.apache.directory.shared.kerberos.components.EncKrbPrivPart;
049import org.apache.directory.shared.kerberos.components.EncryptedData;
050import org.apache.directory.shared.kerberos.components.EncryptionKey;
051import org.apache.directory.shared.kerberos.components.HostAddress;
052import org.apache.directory.shared.kerberos.components.HostAddresses;
053import org.apache.directory.shared.kerberos.components.PrincipalName;
054import org.apache.directory.shared.kerberos.exceptions.ErrorType;
055import org.apache.directory.shared.kerberos.exceptions.KerberosException;
056import org.apache.directory.shared.kerberos.messages.ApRep;
057import org.apache.directory.shared.kerberos.messages.ApReq;
058import org.apache.directory.shared.kerberos.messages.Authenticator;
059import org.apache.directory.shared.kerberos.messages.ChangePasswdData;
060import org.apache.directory.shared.kerberos.messages.EncApRepPart;
061import org.apache.directory.shared.kerberos.messages.KrbPriv;
062import org.apache.directory.shared.kerberos.messages.Ticket;
063import org.apache.mina.core.session.IoSession;
064import org.slf4j.Logger;
065import org.slf4j.LoggerFactory;
066
067public final class ChangePasswordService
068{
069    /** the logger for this class */
070    private static final Logger LOG = LoggerFactory.getLogger( ChangePasswordService.class );
071
072    private static final CipherTextHandler CIPHER_TEXT_HANDLER = new CipherTextHandler();
073
074
075    private ChangePasswordService()
076    {
077    }
078
079
080    public static void execute( IoSession session, ChangePasswordContext changepwContext ) throws Exception
081    {
082        if ( LOG.isDebugEnabled() )
083        {
084            monitorRequest( changepwContext );
085        }
086        
087        configureChangePassword( changepwContext );
088        getAuthHeader( changepwContext );
089        verifyServiceTicket( changepwContext );
090        getServerEntry( changepwContext );
091        verifyServiceTicketAuthHeader( changepwContext );
092        extractPassword( changepwContext );
093        
094        if ( LOG.isDebugEnabled() )
095        {
096            monitorContext( changepwContext );
097        }
098        
099        processPasswordChange( changepwContext );
100        buildReply( changepwContext );
101        
102        if ( LOG.isDebugEnabled() )
103        {
104            monitorReply( changepwContext );
105        }
106    }
107    
108    
109    private static void processPasswordChange( ChangePasswordContext changepwContext ) throws KerberosException
110    {
111        PrincipalStore store = changepwContext.getStore();
112        Authenticator authenticator = changepwContext.getAuthenticator();
113        String newPassword = Strings.utf8ToString( changepwContext.getPasswordData().getNewPasswd() );
114        KerberosPrincipal byPrincipal = KerberosUtils.getKerberosPrincipal( 
115            authenticator.getCName(),
116            authenticator.getCRealm() );
117
118        KerberosPrincipal targetPrincipal = null;
119
120        PrincipalName targName = changepwContext.getPasswordData().getTargName();
121        
122        if ( targName != null )
123        {
124            targetPrincipal = new KerberosPrincipal( targName.getNameString(), PrincipalNameType.KRB_NT_PRINCIPAL.getValue() );
125        }
126        else
127        {
128            targetPrincipal = byPrincipal;
129        }
130        
131        // usec and seq-number must be present per MS but aren't in legacy kpasswd
132        // seq-number must have same value as authenticator
133        // ignore r-address
134
135        store.changePassword( byPrincipal, targetPrincipal, newPassword, changepwContext.getTicket().getEncTicketPart().getFlags().isInitial() );
136        LOG.debug( "Successfully modified password for {} BY {}.", targetPrincipal, byPrincipal );
137    }
138    
139    
140    private static void monitorRequest( ChangePasswordContext changepwContext ) throws KerberosException
141    {
142        try
143        {
144            ChangePasswordRequest request = ( ChangePasswordRequest ) changepwContext.getRequest();
145            short versionNumber = request.getVersionNumber();
146
147            StringBuffer sb = new StringBuffer();
148            sb.append( "Responding to change password request:" );
149            sb.append( "\n\t" + "versionNumber    " + versionNumber );
150
151            LOG.debug( sb.toString() );
152        }
153        catch ( Exception e )
154        {
155            // This is a monitor.  No exceptions should bubble up.
156            LOG.error( I18n.err( I18n.ERR_152 ), e );
157        }
158    }
159    
160    
161    private static void configureChangePassword( ChangePasswordContext changepwContext )
162    {
163        changepwContext.setCipherTextHandler( CIPHER_TEXT_HANDLER );
164    }
165    
166    
167    private static void getAuthHeader( ChangePasswordContext changepwContext ) throws KerberosException
168    {
169        ChangePasswordRequest request = ( ChangePasswordRequest ) changepwContext.getRequest();
170
171        short pvno = request.getVersionNumber();
172        
173        if ( ( pvno != AbstractPasswordMessage.PVNO ) && ( pvno != AbstractPasswordMessage.OLD_PVNO ) )
174        {
175            throw new ChangePasswordException( ChangePasswdErrorType.KRB5_KPASSWD_BAD_VERSION );
176        }
177
178        if ( request.getAuthHeader() == null || request.getAuthHeader().getTicket() == null )
179        {
180            throw new ChangePasswordException( ChangePasswdErrorType.KRB5_KPASSWD_AUTHERROR );
181        }
182
183        ApReq authHeader = request.getAuthHeader();
184        Ticket ticket = authHeader.getTicket();
185
186        changepwContext.setAuthHeader( authHeader );
187        changepwContext.setTicket( ticket );
188    }
189    
190    
191    private static void verifyServiceTicket( ChangePasswordContext changepwContext ) throws KerberosException
192    {
193        ChangePasswordConfig config = changepwContext.getConfig();
194        Ticket ticket = changepwContext.getTicket();
195        String primaryRealm = config.getPrimaryRealm();
196        KerberosPrincipal changepwPrincipal = config.getServicePrincipal();
197        KerberosPrincipal serverPrincipal = KerberosUtils.getKerberosPrincipal( ticket.getSName(), ticket.getRealm() ); 
198
199        // for some reason kpassword is setting the pricnipaltype value as 1 for ticket.getSName()
200        // hence changing to string based comparison for server and changepw principals
201        // instead of serverPrincipal.equals( changepwPrincipal )
202        if ( !ticket.getRealm().equals( primaryRealm ) || !serverPrincipal.getName().equals( changepwPrincipal.getName() ) )
203        {
204            throw new KerberosException( org.apache.directory.shared.kerberos.exceptions.ErrorType.KRB_AP_ERR_NOT_US );
205        }
206    }
207    
208    
209    private static void getServerEntry( ChangePasswordContext changepwContext ) throws KerberosException
210    {
211        Ticket ticket = changepwContext.getTicket();
212        KerberosPrincipal principal =  KerberosUtils.getKerberosPrincipal( ticket.getSName(), ticket.getRealm() );
213        PrincipalStore store = changepwContext.getStore();
214
215        changepwContext.setServerEntry( KerberosUtils.getEntry( principal, store, ErrorType.KDC_ERR_S_PRINCIPAL_UNKNOWN ) );
216    }
217    
218    
219    private static void verifyServiceTicketAuthHeader( ChangePasswordContext changepwContext ) throws KerberosException
220    {
221        ApReq authHeader = changepwContext.getAuthHeader();
222        Ticket ticket = changepwContext.getTicket();
223
224        EncryptionType encryptionType = ticket.getEncPart().getEType();
225        EncryptionKey serverKey = changepwContext.getServerEntry().getKeyMap().get( encryptionType );
226
227        long clockSkew = changepwContext.getConfig().getAllowableClockSkew();
228        ReplayCache replayCache = changepwContext.getReplayCache();
229        boolean emptyAddressesAllowed = changepwContext.getConfig().isEmptyAddressesAllowed();
230        InetAddress clientAddress = changepwContext.getClientAddress();
231        CipherTextHandler cipherTextHandler = changepwContext.getCipherTextHandler();
232
233        Authenticator authenticator = KerberosUtils.verifyAuthHeader( authHeader, ticket, serverKey, clockSkew, replayCache,
234            emptyAddressesAllowed, clientAddress, cipherTextHandler, KeyUsage.AP_REQ_AUTHNT_SESS_KEY, false );
235
236        changepwContext.setAuthenticator( authenticator );
237    }
238    
239    
240    private static void extractPassword( ChangePasswordContext changepwContext ) throws Exception
241    {
242        ChangePasswordRequest request = ( ChangePasswordRequest ) changepwContext.getRequest();
243        Authenticator authenticator = changepwContext.getAuthenticator();
244        CipherTextHandler cipherTextHandler = changepwContext.getCipherTextHandler();
245
246        // get the subsession key from the Authenticator
247        EncryptionKey subSessionKey = authenticator.getSubKey();
248
249        // decrypt the request's private message with the subsession key
250        EncryptedData encReqPrivPart = request.getPrivateMessage().getEncPart();
251
252        ChangePasswdData passwordData = null;
253        
254        try
255        {
256            byte[] decryptedData = cipherTextHandler.decrypt( subSessionKey, encReqPrivPart, KeyUsage.KRB_PRIV_ENC_PART_CHOSEN_KEY );
257            EncKrbPrivPart privatePart = KerberosDecoder.decodeEncKrbPrivPart( decryptedData );
258
259            if ( authenticator.getSeqNumber() != privatePart.getSeqNumber() )
260            {
261                throw new ChangePasswordException( ChangePasswdErrorType.KRB5_KPASSWD_MALFORMED );    
262            }
263            
264            if ( request.getVersionNumber() == AbstractPasswordMessage.OLD_PVNO )
265            {
266                passwordData = new ChangePasswdData();
267                passwordData.setNewPasswd( privatePart.getUserData() );
268            }
269            else
270            {
271                Asn1Decoder passwordDecoder = new Asn1Decoder();
272                ByteBuffer stream = ByteBuffer.wrap( privatePart.getUserData() );
273                ChangePasswdDataContainer container = new ChangePasswdDataContainer( stream );
274                passwordDecoder.decode( stream, container );
275                passwordData = container.getChngPwdData();
276            }
277        }
278        catch ( KerberosException ke )
279        {
280            throw new ChangePasswordException( ChangePasswdErrorType.KRB5_KPASSWD_SOFTERROR, ke );
281        }
282
283        changepwContext.setChngPwdData( passwordData );
284    }
285
286    
287    private static void monitorContext( ChangePasswordContext changepwContext ) throws KerberosException
288    {
289        try
290        {
291            PrincipalStore store = changepwContext.getStore();
292            ApReq authHeader = changepwContext.getAuthHeader();
293            Ticket ticket = changepwContext.getTicket();
294            ReplayCache replayCache = changepwContext.getReplayCache();
295            long clockSkew = changepwContext.getConfig().getAllowableClockSkew();
296
297            Authenticator authenticator = changepwContext.getAuthenticator();
298            KerberosPrincipal clientPrincipal = KerberosUtils.getKerberosPrincipal( 
299                authenticator.getCName(), authenticator.getCRealm() );
300
301            InetAddress clientAddress = changepwContext.getClientAddress();
302            HostAddresses clientAddresses = ticket.getEncTicketPart().getClientAddresses();
303
304            boolean caddrContainsSender = false;
305
306            if ( ticket.getEncTicketPart().getClientAddresses() != null )
307            {
308                caddrContainsSender = ticket.getEncTicketPart().getClientAddresses().contains( new HostAddress( clientAddress ) );
309            }
310
311            StringBuffer sb = new StringBuffer();
312            sb.append( "Monitoring context:" );
313            sb.append( "\n\t" + "store                  " + store );
314            sb.append( "\n\t" + "authHeader             " + authHeader );
315            sb.append( "\n\t" + "ticket                 " + ticket );
316            sb.append( "\n\t" + "replayCache            " + replayCache );
317            sb.append( "\n\t" + "clockSkew              " + clockSkew );
318            sb.append( "\n\t" + "clientPrincipal        " + clientPrincipal );
319            sb.append( "\n\t" + "ChangePasswdData        " + changepwContext.getPasswordData() );
320            sb.append( "\n\t" + "clientAddress          " + clientAddress );
321            sb.append( "\n\t" + "clientAddresses        " + clientAddresses );
322            sb.append( "\n\t" + "caddr contains sender  " + caddrContainsSender );
323            sb.append( "\n\t" + "Ticket principal       " + ticket.getSName() );
324
325            PrincipalStoreEntry ticketPrincipal = changepwContext.getServerEntry();
326            
327            sb.append( "\n\t" + "cn                     " + ticketPrincipal.getCommonName() );
328            sb.append( "\n\t" + "realm                  " + ticketPrincipal.getRealmName() );
329            sb.append( "\n\t" + "Service principal      " + ticketPrincipal.getPrincipal() );
330            sb.append( "\n\t" + "SAM type               " + ticketPrincipal.getSamType() );
331
332            EncryptionType encryptionType = ticket.getEncPart().getEType();
333            int keyVersion = ticketPrincipal.getKeyMap().get( encryptionType ).getKeyVersion();
334            sb.append( "\n\t" + "Ticket key type        " + encryptionType );
335            sb.append( "\n\t" + "Service key version    " + keyVersion );
336
337            LOG.debug( sb.toString() );
338        }
339        catch ( Exception e )
340        {
341            // This is a monitor.  No exceptions should bubble up.
342            LOG.error( I18n.err( I18n.ERR_154 ), e );
343        }
344    }
345    
346    
347    private static void buildReply( ChangePasswordContext changepwContext ) throws KerberosException, UnknownHostException
348    {
349        Authenticator authenticator = changepwContext.getAuthenticator();
350        Ticket ticket = changepwContext.getTicket();
351        CipherTextHandler cipherTextHandler = changepwContext.getCipherTextHandler();
352
353        // begin building reply
354
355        // create priv message
356        // user-data component is short result code
357        EncKrbPrivPart privPart = new EncKrbPrivPart();
358        // first two bytes are the result code, rest is the string 'Password Changed' followed by a null char
359        byte[] resultCode =
360            { ( byte ) 0x00, ( byte ) 0x00, ( byte ) 0x50, ( byte ) 0x61, ( byte ) 0x73, ( byte ) 0x73, ( byte ) 0x77,
361                ( byte ) 0x6F, ( byte ) 0x72, ( byte ) 0x64, ( byte ) 0x20, ( byte ) 0x63, ( byte ) 0x68,
362                ( byte ) 0x61, ( byte ) 0x6E, ( byte ) 0x67, ( byte ) 0x65, ( byte ) 0x64, ( byte ) 0x00 };
363        privPart.setUserData( resultCode );
364
365        privPart.setSenderAddress( new HostAddress( Network.LOOPBACK ) );
366
367        // get the subsession key from the Authenticator
368        EncryptionKey subSessionKey = authenticator.getSubKey();
369
370        EncryptedData encPrivPart;
371
372        try
373        {
374            encPrivPart = cipherTextHandler.seal( subSessionKey, privPart, KeyUsage.KRB_PRIV_ENC_PART_CHOSEN_KEY );
375        }
376        catch ( KerberosException ke )
377        {
378            throw new ChangePasswordException( ChangePasswdErrorType.KRB5_KPASSWD_SOFTERROR, ke );
379        }
380
381        KrbPriv privateMessage = new KrbPriv();
382        privateMessage.setEncPart( encPrivPart );
383
384        // Begin AP_REP generation
385        EncApRepPart repPart = new EncApRepPart();
386        repPart.setCTime( authenticator.getCtime() );
387        repPart.setCusec( authenticator.getCusec() );
388        
389        if ( authenticator.getSeqNumber() != null )
390        {
391            repPart.setSeqNumber( authenticator.getSeqNumber() );
392        }
393        
394        repPart.setSubkey( subSessionKey );
395
396        EncryptedData encRepPart;
397
398        try
399        {
400            encRepPart = cipherTextHandler.seal( ticket.getEncTicketPart().getKey(), repPart, KeyUsage.AP_REP_ENC_PART_SESS_KEY );
401        }
402        catch ( KerberosException ke )
403        {
404            throw new ChangePasswordException( ChangePasswdErrorType.KRB5_KPASSWD_SOFTERROR, ke );
405        }
406
407        ApRep appReply = new ApRep();
408        appReply.setEncPart( encRepPart );
409
410        // return status message value object, the version number 
411        changepwContext.setReply( new ChangePasswordReply( AbstractPasswordMessage.OLD_PVNO, appReply, privateMessage ) );
412    }
413
414    
415    private static void monitorReply( ChangePasswordContext changepwContext ) throws KerberosException
416    {
417        try
418        {
419            ChangePasswordReply reply = ( ChangePasswordReply ) changepwContext.getReply();
420            ApRep appReply = reply.getApplicationReply();
421            KrbPriv priv = reply.getPrivateMessage();
422
423            StringBuilder sb = new StringBuilder();
424            sb.append( "Responding with change password reply:" );
425            sb.append( "\n\t" + "appReply               " + appReply );
426            sb.append( "\n\t" + "priv                   " + priv );
427
428            LOG.debug( sb.toString() );
429        }
430        catch ( Exception e )
431        {
432            // This is a monitor.  No exceptions should bubble up.
433            LOG.error( I18n.err( I18n.ERR_155 ), e );
434        }
435    }
436}