001    /* GSSContext.java -- The GSS context interface.
002       Copyright (C) 2004 Free Software Foundation, Inc.
003    
004    This file is part of GNU Classpath.
005    
006    GNU Classpath is free software; you can redistribute it and/or modify
007    it under the terms of the GNU General Public License as published by
008    the Free Software Foundation; either version 2, or (at your option)
009    any later version.
010    
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013    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014    General Public License for more details.
015    
016    You should have received a copy of the GNU General Public License
017    along with GNU Classpath; see the file COPYING.  If not, write to the
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019    02110-1301 USA.
020    
021    Linking this library statically or dynamically with other modules is
022    making a combined work based on this library.  Thus, the terms and
023    conditions of the GNU General Public License cover the whole
024    combination.
025    
026    As a special exception, the copyright holders of this library give you
027    permission to link this library with independent modules to produce an
028    executable, regardless of the license terms of these independent
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031    independent module, the terms and conditions of the license of that
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036    exception statement from your version. */
037    
038    
039    package org.ietf.jgss;
040    
041    import java.io.InputStream;
042    import java.io.OutputStream;
043    
044    /**
045     * <p>This interface encapsulates the GSS-API security context and provides
046     * the security services ({@link #wrap(byte[],int,int,org.ietf.jgss.MessageProp)},
047     * {@link #unwrap(byte[],int,int,org.ietf.jgss.MessageProp)}, {@link
048     * #getMIC(byte[],int,int,org.ietf.jgss.MessageProp)}, {@link
049     * #verifyMIC(byte[],int,int,byte[],int,int,org.ietf.jgss.MessageProp)}) that
050     * are available over the context.  Security contexts are established
051     * between peers using locally acquired credentials.  Multiple contexts
052     * may exist simultaneously between a pair of peers, using the same or
053     * different set of credentials.  GSS-API functions in a manner
054     * independent of the underlying transport protocol and depends on its
055     * calling application to transport its tokens between peers.</p>
056     *
057     * <p>Before the context establishment phase is initiated, the context
058     * initiator may request specific characteristics desired of the
059     * established context.  These can be set using the set methods.  After
060     * the context is established, the caller can check the actual
061     * characteristic and services offered by the context using the query
062     * methods.</p>
063     *
064     * <p>The context establishment phase begins with the first call to the
065     * init method by the context initiator.  During this phase the
066     * {@link #initSecContext(byte[],int,int)} and {@link
067     * #acceptSecContext(byte[],int,int)} methods will produce GSS-API
068     * authentication tokens which the calling application needs to send to
069     * its peer.  If an error occurs at any point, an exception will get
070     * thrown and the code will start executing in a catch block.  If not,
071     * the normal flow of code continues and the application can make a call
072     * to the {@link #isEstablished()} method. If this method returns false it
073     * indicates that a token is needed from its peer in order to continue
074     * the context establishment phase.  A return value of true signals that
075     * the local end of the context is established.  This may still require
076     * that a token be sent to the peer, if one is produced by GSS-API.
077     * During the context establishment phase, the {@link #isProtReady()}
078     * method may be called to determine if the context can be used for the
079     * per-message operations.  This allows applications to use per-message
080     * operations on contexts which aren't fully established.</p>
081     *
082     * <p>After the context has been established or the {@link #isProtReady()}
083     * method returns <code>true</code>, the query routines can be invoked to
084     * determine the actual characteristics and services of the established
085     * context.  The application can also start using the per-message methods
086     * of {@link #wrap(byte[],int,int,org.ietf.jgss.MessageProp)} and
087     * {@link #getMIC(byte[],int,int,org.ietf.jgss.MessageProp)} to obtain
088     * cryptographic operations on application supplied data.</p>
089     *
090     * <p>When the context is no longer needed, the application should call
091     * {@link dispose()} to release any system resources the context may be
092     * using.</p>
093     *
094     * <h3>Example Code</h3>
095     *
096     * <pre>
097    GSSManager mgr = GSSManager.getInstance();
098    
099    // start by creating the name for a service entity
100    GSSName targetName = mgr.createName("service@host",
101                                        GSSName.NT_HOSTBASED_SERVICE);
102    
103    // create a context using default credentials for the above entity
104    // and the implementation specific default mechanism
105    GSSContext context = mgr.createContext(targetName,
106                                           null,   // default mechanism
107                                           null,   // default credentials
108                                           GSSContext.INDEFINITE_LIFETIME);
109    
110    // set desired context options - all others are false by default
111    context.requestConf(true);
112    context.requestMutualAuth(true);
113    context.requestReplayDet(true);
114    context.requestSequenceDet(true);
115    
116    // establish a context between peers - using byte arrays
117    byte []inTok = new byte[0];
118    
119    try
120      {
121        do
122          {
123            byte[] outTok = context.initSecContext(inTok, 0,
124                                                   inTok.length);
125    
126            // send the token if present
127            if (outTok != null)
128              sendToken(outTok);
129    
130            // check if we should expect more tokens
131            if (context.isEstablished())
132              break;
133    
134            // another token expected from peer
135            inTok = readToken();
136    
137          }
138        while (true);
139      }
140    catch (GSSException e)
141      {
142        print("GSSAPI error: " + e.getMessage());
143      }
144    
145    // display context information
146    print("Remaining lifetime in seconds = " + context.getLifetime());
147    print("Context mechanism = " + context.getMech().toString());
148    print("Initiator = " + context.getSrcName().toString());
149    print("Acceptor = " + context.getTargName().toString());
150    
151    if (context.getConfState())
152      print("Confidentiality security service available");
153    
154    if (context.getIntegState())
155      print("Integrity security service available");
156    
157    // perform wrap on an application supplied message, appMsg,
158    // using QOP = 0, and requesting privacy service
159    byte[] appMsg ...
160    MessageProp mProp = new MessageProp(0, true);
161    byte[] tok = context.wrap(appMsg, 0, appMsg.length, mProp);
162    
163    if (mProp.getPrivacy())
164      print("Message protected with privacy.");
165    
166    sendToken(tok);
167    
168    
169    // release the local-end of the context
170    context.dispose();
171     * </pre>
172     */
173    public interface GSSContext
174    {
175    
176      // Constants.
177      // -------------------------------------------------------------------------
178    
179      /**
180       * A lifetime constant representing the default context lifetime.
181       */
182      int DEFAULT_LIFETIME = 0;
183    
184      /**
185       * A lifetime constant representing indefinite context lifetime.
186       */
187      int INDEFINITE_LIFETIME = Integer.MAX_VALUE;
188    
189      // Methods.
190      // -------------------------------------------------------------------------
191    
192      /**
193       * <p>Called by the context initiator to start the context creation
194       * process.  This is equivalent to the stream based method except that
195       * the token buffers are handled as byte arrays instead of using stream
196       * objects.  This method may return an output token which the
197       * application will need to send to the peer for processing by the
198       * accept call.  Typically, the application would do so by calling the
199       * {@link OutputStream#flush()} method on an OutputStream that
200       * encapsulates the connection between the two peers.  The application
201       * can call {@link #isEstablished()} to determine if the context
202       * establishment phase is complete for this peer.  A return value of
203       * <code>false</code> from {@link #isEstablished()} indicates that more
204       * tokens are expected to be supplied to the initSecContext() method. Note
205       * that it is possible that the initSecContext() method return a token for
206       * the peer, and {@link #isEstablished()} to return <code>true</code> also.
207       * This indicates that the token needs to be sent to the peer, but the local
208       * end of the context is now fully established.</p>
209       *
210       * <p>Upon completion of the context establishment, the available context
211       * options may be queried through the get methods.</p>
212       *
213       * @param inputBuf Token generated by the peer. This parameter is ignored
214       *                 on the first call.
215       * @param offset   The offset within the <i>inputBuf</i> where the token
216       *                 begins.
217       * @param len      The length of the token within the <i>inputBuf</i>
218       *                 (starting at the offset).
219       * @return The output token, if any.
220       * @throws GSSException If this operation fails.
221       */
222      byte[] initSecContext(byte[] inputBuf, int offset, int len)
223        throws GSSException;
224    
225      /**
226       * <p>Called by the context initiator to start the context creation
227       * process.  This is equivalent to the byte array based method.  This
228       * method may write an output token to the <i>outStream</i>, which the
229       * application will need to send to the peer for processing by the
230       * accept call. Typically, the application would do so by calling the
231       * {@link OutputStream#flush()} method on an OutputStream that encapsulates
232       * the connection between the two peers. The application can call {@link
233       * #isEstablished()} to determine if the context establishment phase is
234       * complete for this peer. A return value of <code>false</code> from
235       * isEstablished indicates that more tokens are expected to be supplied
236       * to the initSecContext() method. Note that it is possible that the
237       * initSecContext() method return a token for the peer, and {@link
238       * #isEstablished() return <code>true</code> also. This indicates that
239       * the token needs to be sent to the peer, but the local end of the context
240       * is now fully established.</p>
241       *
242       * <p>The GSS-API authentication tokens contain a definitive start and end.
243       * This method will attempt to read one of these tokens per invocation,
244       * and may block on the stream if only part of the token is available.</p>
245       *
246       * <p>Upon completion of the context establishment, the available context
247       * options may be queried through the get methods.</p>
248       *
249       * @param inStream  Contains the token generated by the peer. This
250       *                  parameter is ignored on the first call.
251       * @param outStream Output stream where the output token will be written.
252       *                  During the final stage of context establishment, there
253       *                  may be no bytes written.
254       * @return The number of bytes written to <i>outStream</i>, or 0 if no
255       *         token is written.
256       * @throws GSSException If this operation fails.
257       */
258      int initSecContext(InputStream inStream, OutputStream outStream)
259        throws GSSException;
260    
261      /**
262       * <p>Called by the context acceptor upon receiving a token from the peer.
263       * This call is equivalent to the stream based method except that the
264       * token buffers are handled as byte arrays instead of using stream
265       * objects.</p>
266       *
267       * <p>This method may return an output token which the application will
268       * need to send to the peer for further processing by the init call.</p>
269       *
270       * <p><code>null</code> return value indicates that no token needs to be
271       * sent to the peer. The application can call {@link #isEstablished()}
272       * to determine if the context establishment phase is complete for this
273       * peer. A return value of <code>false</code> from {@link #isEstablished()}
274       * indicates that more tokens are expected to be supplied to this
275       * method.</p>
276       *
277       * <p>Note that it is possible that acceptSecContext() return a token for
278       * the peer, and isEstablished() return <code>true</code> also. This
279       * indicates that the token needs to be sent to the peer, but the local
280       * end of the context is now fully established.</p>
281       *
282       * <p>Upon completion of the context establishment, the available context
283       * options may be queried through the get methods.</p>
284       *
285       * @param inTok  Token generated by the peer.
286       * @param offset The offset within the <i>inTok</i> where the token begins.
287       * @param len    The length of the token within the <i>inTok</i> (starting
288       *               at the offset).
289       * @return The output token, if any.
290       * @throws GSSException If this operation fails.
291       */
292      byte[] acceptSecContext(byte[] inTok, int offset, int len)
293        throws GSSException;
294    
295      /**
296       * <p>Called by the context acceptor upon receiving a token from the peer.
297       * This call is equivalent to the byte array method.  It may write an
298       * output token to the outStream, which the application will need to
299       * send to the peer for processing by its initSecContext method.
300       * Typically, the application would do so by calling the {@link
301       * OutputStream#flush()} method on an OutputStream that encapsulates the
302       * connection between the two peers. The application can call {@link
303       * #isEstablished()} to determine if the context establishment phase is
304       * complete for this peer. A return value of <code>false</code> from
305       * {@link #isEstablished()} indicates that more tokens are expected to be
306       * supplied to this method.</p>
307       *
308       * <p>Note that it is possible that acceptSecContext() return a token for
309       * the peer, and isEstablished() return <code>true</code> also. This
310       * indicates that the token needs to be sent to the peer, but the local
311       * end of the context is now fully established.</p>
312       *
313       * <p>The GSS-API authentication tokens contain a definitive start and end.
314       * This method will attempt to read one of these tokens per invocation,
315       * and may block on the stream if only part of the token is available.</p>
316       *
317       * <p>Upon completion of the context establishment, the available context
318       * options may be queried through the get methods.</p>
319       *
320       * @param inStream  Contains the token generated by the peer.
321       * @param outStream Output stream where the output token will be written.
322       *                  During the final stage of context establishment, there
323       *                  may be no bytes written.
324       * @return The number of bytes written, or 0 if no token is written.
325       * @throws GSSException If this operation fails.
326       */
327      void acceptSecContext(InputStream inStream, OutputStream outStream)
328        throws GSSException;
329    
330      /**
331       * Used during context establishment to determine the state of the
332       * context. Returns <code>true</code> if this is a fully established
333       * context on the caller's side and no more tokens are needed from the
334       * peer. Should be called after a call to {@link
335       * #initSecContext(byte[],int,int)} or {@link
336       * #acceptSecContext(byte[],int,int)} when no {@link GSSException}
337       * is thrown.
338       *
339       * @return True of this context is fully established on this side.
340       */
341      boolean isEstablished();
342    
343      /**
344       * Releases any system resources and cryptographic information stored in
345       * the context object. This will invalidate the context.
346       *
347       * @throws GSSException If this operation fails.
348       */
349      void dispose() throws GSSException;
350    
351      /**
352       * <p>Returns the maximum message size that, if presented to the
353       * {@link #wrap(byte[],int,int,org.ietf.jgss.MessageProp)} method with
354       * the same <i>confReq</i> and <i>qop</i> parameters, will result in an
355       * output token containing no more than the <i>maxTokenSize</i> bytes.</p>
356       *
357       * <p>This call is intended for use by applications that communicate over
358       * protocols that impose a maximum message size.  It enables the
359       * application to fragment messages prior to applying protection.</p>
360       *
361       * <p>GSS-API implementations are recommended but not required to detect
362       * invalid QOP values when getWrapSizeLimit is called.  This routine
363       * guarantees only a maximum message size, not the availability of
364       * specific QOP values for message protection.</p>
365       *
366       * <p>Successful completion of this call does not guarantee that wrap will
367       * be able to protect a message of the computed length, since this
368       * ability may depend on the availability of system resources at the
369       * time that wrap is called.  However, if the implementation itself
370       * imposes an upper limit on the length of messages that may be
371       * processed by wrap, the implementation should not return a value that
372       * is greater than this length.</p>
373       *
374       * @param qop          Indicates the level of protection wrap will be asked
375       *                     to provide.
376       * @param confReq      Indicates if wrap will be asked to provide privacy
377       *                     service.
378       * @param maxTokenSize The desired maximum size of the token emitted
379       *                     by {@link #wrap(byte[],int,int,org.ietf.jgss.MessageProp)}.
380       * @return The maximum wrapped output size.
381       * @throws GSSException If this operation fails.
382       */
383      int getWrapSizeLimit(int qop, boolean confReq, int maxTokenSize)
384        throws GSSException;
385    
386      /**
387       * <p>Applies per-message security services over the established security
388       * context.  The method will return a token with a cryptographic MIC and
389       * may optionally encrypt the specified <i>inBuf</i>. This method is
390       * equivalent in functionality to its stream counterpart. The returned
391       * byte array will contain both the MIC and the message.</p>
392       *
393       * <p>The {@link MessageProp} object is instantiated by the application
394       * and used to specify a QOP value which selects cryptographic algorithms,
395       * and a privacy service to optionally encrypt the message. The underlying
396       * mechanism that is used in the call may not be able to provide the
397       * privacy service.  It sets the actual privacy service that it does
398       * provide in this {@link MessageProp} object which the caller should then
399       * query upon return. If the mechanism is not able to provide the
400       * requested QOP, it throws a {@link GSSException} with the {@link
401       * GSSException#BAD_QOP} code.</p>
402       *
403       * <p>Since some application-level protocols may wish to use tokens emitted
404       * by wrap to provide "secure framing", implementations should support
405       * the wrapping of zero-length messages.</p>
406       *
407       * <p>The application will be responsible for sending the token to the
408       * peer.</p>
409       *
410       * @param inBuf   Application data to be protected.
411       * @param offset  The offset within the inBuf where the data begins.
412       * @param len     The length of the data within the inBuf (starting at
413       *                the offset).
414       * @param msgProp Instance of {@link MessageProp} that is used by the
415       *                application to set the desired QOP and privacy state.
416       *                Set the desired QOP to 0 to request the default QOP.
417       *                Upon return from this method, this object will contain
418       *                the the actual privacy state that was applied to the
419       *                message by the underlying mechanism.
420       * @return The wrapped data.
421       * @throws GSSException If this operation fails.
422       */
423      byte[] wrap(byte[] inBuf, int offset, int len, MessageProp msgProp)
424        throws GSSException;
425    
426      /**
427       * <p>Allows to apply per-message security services over the established
428       * security context.  The method will produce a token with a
429       * cryptographic MIC and may optionally encrypt the message in inStream.
430       * The outStream will contain both the MIC and the message.</p>
431       *
432       * <p>The {@link MessageProp} object is instantiated by the application and
433       * used to specify a QOP value which selects cryptographic algorithms, and
434       * a privacy service to optionally encrypt the message.  The underlying
435       * mechanism that is used in the call may not be able to provide the
436       * privacy service.  It sets the actual privacy service that it does
437       * provide in this MessageProp object which the caller should then query
438       * upon return.  If the mechanism is not able to provide the requested
439       * QOP, it throws a {@link GSSException} with the {@link
440       * GSSException#BAD_QOP} code.</p>
441       *
442       * <p>Since some application-level protocols may wish to use tokens emitted
443       * by wrap to provide "secure framing", implementations should support
444       * the wrapping of zero-length messages.</p>
445       *
446       * <p>The application will be responsible for sending the token to the
447       * peer.</p>
448       *
449       * @param inStream  Input stream containing the application data to be
450       *                  protected.
451       * @param outStream The output stream to write the protected message to.
452       *                  The application is responsible for sending this to the
453       *                  other peer for processing in its unwrap method.
454       * @param msgProp   Instance of {@link MessageProp} that is used by the
455       *                  application to set the desired QOP and privacy state.
456       *                  Set the desired QOP to 0 to request the default QOP.
457       *                  Upon return from this method, this object will contain
458       *                  the the actual privacy state that was applied to the
459       *                  message by the underlying mechanism.
460       * @throws GSSException If this operation fails.
461       */
462      void wrap(InputStream inStream, OutputStream outStream, MessageProp msgProp)
463        throws GSSException;
464    
465      /**
466       * <p>Used by the peer application to process tokens generated with the
467       * wrap call. This call is equal in functionality to its stream
468       * counterpart. The method will return the message supplied in the peer
469       * application to the wrap call, verifying the embedded MIC.</p>
470       *
471       * <p>The {@link MessageProp} object is instantiated by the application and
472       * is used by the underlying mechanism to return information to the caller
473       * such as the QOP, whether confidentiality was applied to the message, and
474       * other supplementary message state information.</p>
475       *
476       * <p>Since some application-level protocols may wish to use tokens emitted
477       * by wrap to provide "secure framing", implementations should support
478       * the wrapping and unwrapping of zero-length messages.</p>
479       *
480       * @param inBuf   GSS-API wrap token received from peer.
481       * @param offset  The offset within the inBuf where the token begins.
482       * @param len     The length of the token within the inBuf (starting at
483       *                the offset).
484       * @param msgProp Upon return from the method, this object will contain
485       *                the applied QOP, the privacy state of the message, and
486       *                supplementary information stating whether the token was
487       *                a duplicate, old, out of sequence or arriving after a gap.
488       * @return The unwrapped token.
489       * @throws GSSException If this operation fails.
490       */
491      byte[] unwrap(byte[] inBuf, int offset, int len, MessageProp msgProp)
492        throws GSSException;
493    
494      /**
495       * <p>Used by the peer application to process tokens generated with the
496       * wrap call.  This call is equal in functionality to its byte array
497       * counterpart.  It will produce the message supplied in the peer
498       * application to the wrap call, verifying the embedded MIC.</p>
499       *
500       * <p>The {@link MessageProp} object is instantiated by the application
501       * and is used by the underlying mechanism to return information to the
502       * caller such as the QOP, whether confidentiality was applied to the
503       * message, and other supplementary message state information.</p>
504       *
505       * <p>Since some application-level protocols may wish to use tokens emitted
506       * by wrap to provide "secure framing", implementations should support
507       * the wrapping and unwrapping of zero-length messages.</p>
508       *
509       * @param inStream  Input stream containing the GSS-API wrap token
510       *                  received from the peer.
511       * @param outStream The output stream to write the application message to.
512       * @param msgProp   Upon return from the method, this object will contain
513       *                  the applied QOP, the privacy state of the message, and
514       *                  supplementary information stating whether the token was
515       *                  a duplicate, old, out of sequence or arriving after a gap.
516       * @throws GSSException If this operation fails.
517       */
518      void unwrap(InputStream inStream, OutputStream outStream, MessageProp msgProp)
519        throws GSSException;
520    
521      /**
522       * <p>Returns a token containing a cryptographic MIC for the supplied
523       * message, for transfer to the peer application.  Unlike wrap, which
524       * encapsulates the user message in the returned token, only the message
525       * MIC is returned in the output token.  This method is identical in
526       * functionality to its stream counterpart.</p>
527       *
528       * <p>Note that privacy can only be applied through the wrap call.</p>
529       *
530       * <p>Since some application-level protocols may wish to use tokens emitted
531       * by getMIC to provide "secure framing", implementations should support
532       * derivation of MICs from zero-length messages.</p>
533       *
534       * @param inMsg   Message to generate MIC over.
535       * @param offset  The offset within the inMsg where the token begins.
536       * @param len     The length of the token within the inMsg (starting at
537       *                the offset).
538       * @param msgProp Instance of MessageProp that is used by the
539       *                application to set the desired QOP.  Set the desired
540       *                QOP to 0 in msgProp to request the default QOP.
541       *                Alternatively pass in <code>null</code> for msgProp to
542       *                request default QOP.
543       * @return The MIC.
544       * @throws GSSException If this operation fails.
545       */
546      byte[] getMIC(byte[] inMsg, int offset, int len, MessageProp msgProp)
547        throws GSSException;
548    
549      /**
550       * <p>Produces a token containing a cryptographic MIC for the supplied
551       * message, for transfer to the peer application.  Unlike wrap, which
552       * encapsulates the user message in the returned token, only the message
553       * MIC is produced in the output token.  This method is identical in
554       * functionality to its byte array counterpart.</p>
555       *
556       * <p>Note that privacy can only be applied through the wrap call.</p>
557       *
558       * <p>Since some application-level protocols may wish to use tokens emitted
559       * by getMIC to provide "secure framing", implementations should support
560       * derivation of MICs from zero-length messages.</p>
561       *
562       * @param inStream  Input stream containing the message to generate
563       *                  the MIC over.
564       * @param outStream Output stream to write the GSS-API output token to.
565       * @param mgProp    Instance of MessageProp that is used by the
566       *                  application to set the desired QOP.  Set the desired
567       *                  QOP to 0 in msgProp to request the default QOP.
568       *                  Alternatively pass in <code>null</code> for msgProp
569       *                  to request default QOP.
570       * @throws GSSException If this operation fails.
571       */
572      void getMIC(InputStream inStream, OutputStream outStream, MessageProp mgProp)
573        throws GSSException;
574    
575      /**
576       * <p>Verifies the cryptographic MIC, contained in the token parameter,
577       * over the supplied message.  This method is equivalent in
578       * functionality to its stream counterpart.</p>
579       *
580       * <p>The MessageProp object is instantiated by the application and is used
581       * by the underlying mechanism to return information to the caller such
582       * as the QOP indicating the strength of protection that was applied to
583       * the message and other supplementary message state information.</p>
584       *
585       * <p>Since some application-level protocols may wish to use tokens emitted
586       * by getMIC to provide "secure framing", implementations should support
587       * the calculation and verification of MICs over zero-length messages.</p>
588       *
589       * @param inTok     Token generated by peer's getMIC method.
590       * @param tokOffset The offset within the inTok where the token begins.
591       * @param tokLen    The length of the token within the inTok (starting at
592       *                  the offset).
593       * @param inMsg     Application message to verify the cryptographic MIC
594       *                  over.
595       * @param msgOffset The offset within the inMsg where the message begins.
596       * @param msgLen    The length of the message within the inMsg (starting
597       *                  at the offset).
598       * @param msgProp   Upon return from the method, this object will contain
599       *                  the applied QOP and supplementary information
600       *                  stating whether the token was a duplicate, old, out
601       *                  of sequence or arriving after a gap.  The
602       *                  confidentiality state will be set to <code>false</code>.
603       * @throws GSSException If this operation fails.
604       */
605      void verifyMIC(byte[] inTok, int tokOffset, int tokLen, byte[] inMsg,
606                     int msgOffset, int msgLen, MessageProp msgProp)
607        throws GSSException;
608    
609      /**
610       * <p>Verifies the cryptographic MIC, contained in the token parameter,
611       * over the supplied message.  This method is equivalent in
612       * functionality to its byte array counterpart.</p>
613       *
614       * <p>The MessageProp object is instantiated by the application and is used
615       * by the underlying mechanism to return information to the caller such
616       * as the QOP indicating the strength of protection that was applied to
617       * the message and other supplementary message state information.</p>
618       *
619       * <p>Since some application-level protocols may wish to use tokens emitted
620       * by getMIC to provide "secure framing", implementations should support
621       * the calculation and verification of MICs over zero-length messages.</p>
622       *
623       * @param tokStream Input stream containing the token generated by peer's
624       *                  getMIC method.
625       * @param msgStream Input stream containing the application message to
626       *                  verify the cryptographic MIC over.
627       * @param msgProp   Upon return from the method, this object will contain
628       *                  the applied QOP and supplementary information
629       *                  stating whether the token was a duplicate, old, out of
630       *                  sequence or arriving after a gap.  The confidentiality
631       *                  state will be set to <code>false</code>.
632       * @throws GSSException If this operation fails.
633       */
634      void verifyMIC(InputStream tokStream, InputStream msgStream, MessageProp msgProp)
635        throws GSSException;
636    
637      /**
638       * <p>Provided to support the sharing of work between multiple processes.
639       * This routine will typically be used by the context-acceptor, in an
640       * application where a single process receives incoming connection
641       * requests and accepts security contexts over them, then passes the
642       * established context to one or more other processes for message
643       * exchange.</p>
644       *
645       * <p>This method deactivates the security context and creates an
646       * interprocess token which, when passed to the byte array constructor
647       * of the GSSContext interface in another process, will re-activate the
648       * context in the second process.  Only a single instantiation of a
649       * given context may be active at any one time; a subsequent attempt by
650       * a context exporter to access the exported security context will fail.</p>
651       *
652       * <p>The implementation may constrain the set of processes by which the
653       * interprocess token may be imported, either as a function of local
654       * security policy, or as a result of implementation decisions.  For
655       * example, some implementations may constrain contexts to be passed
656       * only between processes that run under the same account, or which are
657       * part of the same process group.</p>
658       *
659       * <p>The interprocess token may contain security-sensitive information
660       * (for example cryptographic keys).  While mechanisms are encouraged to
661       * either avoid placing such sensitive information within interprocess
662       * tokens, or to encrypt the token before returning it to the
663       * application, in a typical GSS-API implementation this may not be
664       * possible.  Thus the application must take care to protect the
665       * interprocess token, and ensure that any process to which the token is
666       * transferred is trustworthy.</p>
667       *
668       * @return The exported context.
669       * @throws GSSException If this operation fails.
670       */
671      byte[] export() throws GSSException;
672    
673      /**
674       * <p>Sets the request state of the mutual authentication flag for the
675       * context.  This method is only valid before the context creation
676       * process begins and only for the initiator.</p>
677       *
678       * @param state Boolean representing if mutual authentication should
679       *              be requested during context establishment.
680       * @throws GSSException If this operation fails.
681       */
682      void requestMutualAuth(boolean state) throws GSSException;
683    
684      /**
685       * <p>Sets the request state of the replay detection service for the
686       * context.  This method is only valid before the context creation
687       * process begins and only for the initiator.</p>
688       *
689       * @param state Boolean representing if replay detection is desired
690       *              over the established context.
691       * @throws GSSException If this operation fails.
692       */
693      void requestReplayDet(boolean state) throws GSSException;
694    
695      /**
696       * <p>Sets the request state for the sequence checking service of the
697       * context.  This method is only valid before the context creation
698       * process begins and only for the initiator.</p>
699       *
700       * @param state Boolean representing if sequence detection is desired
701       *              over the established context.
702       * @throws GSSException If this operation fails.
703       */
704      void requestSequenceDet(boolean state) throws GSSException;
705    
706      /**
707       * <p>Sets the request state for the credential delegation flag for the
708       * context.  This method is only valid before the context creation
709       * process begins and only for the initiator.</p>
710       *
711       * @param state Boolean representing if credential delegation is
712       *              desired.
713       * @throws GSSException If this operation fails.
714       */
715      void requestCredDeleg(boolean state) throws GSSException;
716    
717      /**
718       * <p>Requests anonymous support over the context.  This method is only
719       * valid before the context creation process begins and only for the
720       * initiator.</p>
721       *
722       * @param state Boolean representing if anonymity support is requested.
723       * @throws GSSException If this operation fails.
724       */
725      void requestAnonymity(boolean state) throws GSSException;
726    
727      /**
728       * <p>Requests that confidentiality service be available over the context.
729       * This method is only valid before the context creation process begins
730       * and only for the initiator.</p>
731       *
732       * @param state Boolean indicating if confidentiality services are to
733       *              be requested for the context.
734       * @throws GSSException If this operation fails.
735       */
736      void requestConf(boolean state) throws GSSException;
737    
738      /**
739       * <p>Requests that integrity services be available over the context. This
740       * method is only valid before the context creation process begins and
741       * only for the initiator.</p>
742       *
743       * @param state Boolean indicating if integrity services are to be
744       *              requested for the context.
745       * @throws GSSException If this operation fails.
746       */
747      void requestInteg(boolean state) throws GSSException;
748    
749      /**
750       * <p>Sets the desired lifetime for the context in seconds. This method is
751       * only valid before the context creation process begins and only for
752       * the initiator. Use {@link #INDEFINITE_LIFETIME} and {@link
753       * #DEFAULT_LIFETIME} to request indefinite or default context lifetime.</p>
754       *
755       * @param lifetime The desired context lifetime in seconds.
756       * @throws GSSException If this operation fails.
757       */
758      void requestLifetime(int lifetime) throws GSSException;
759    
760      /**
761       * <p>Sets the channel bindings to be used during context establishment.
762       * This method is only valid before the context creation process begins.</p>
763       *
764       * @param cb Channel bindings to be used.
765       * @throws GSSException If this operation fails.
766       */
767      void setChannelBinding(ChannelBinding cb) throws GSSException;
768    
769      /**
770       * <p>Returns the state of the delegated credentials for the context.
771       * When issued before context establishment is completed or when the
772       * isProtReady method returns "false", it returns the desired state,
773       * otherwise it will indicate the actual state over the established
774       * context.</p>
775       *
776       * @return The state of the delegated credentials for the context.
777       */
778      boolean getCredDelegState();
779    
780      /**
781       * <p>Returns the state of the mutual authentication option for the
782       * context.  When issued before context establishment completes or when
783       * the isProtReady method returns "false", it returns the desired state,
784       * otherwise it will indicate the actual state over the established
785       * context.</p>
786       *
787       * @return The state of the mutual authentication option.
788       */
789      boolean getMutualAuthState();
790    
791      /**
792       * <p>Returns the state of the replay detection option for the context.
793       * When issued before context establishment completes or when the
794       * isProtReady method returns "false", it returns the desired state,
795       * otherwise it will indicate the actual state over the established
796       * context.</p>
797       *
798       * @return The state of the replay detection option.
799       */
800      boolean getReplayDetState();
801    
802      /**
803       * <p>Returns the state of the sequence detection option for the context.
804       * When issued before context establishment completes or when the
805       * isProtReady method returns "false", it returns the desired state,
806       * otherwise it will indicate the actual state over the established
807       * context.</p>
808       *
809       * @return The state of the sequence detection option.
810       */
811      boolean getSequenceDetState();
812    
813      /**
814       * <p>Returns "true" if this is an anonymous context. When issued before
815       * context establishment completes or when the isProtReady method
816       * returns "false", it returns the desired state, otherwise it will
817       * indicate the actual state over the established context.</p>
818       *
819       * @return True if this is an anonymous context.
820       */
821      boolean getAnonymityState();
822    
823      /**
824       * <p>Returns "true" if the context is transferable to other processes
825       * through the use of the {@link #export()} method. This call is only
826       * valid on fully established contexts.</p>
827       *
828       * @return True if the context is transferable.
829       * @throws GSSException If this operation fails.
830       */
831      boolean isTransferable() throws GSSException;
832    
833      /**
834       * <p>Returns "true" if the per message operations can be applied over
835       * the context.  Some mechanisms may allow the usage of per-message
836       * operations before the context is fully established.  This will also
837       * indicate that the get methods will return actual context state
838       * characteristics instead of the desired ones.</p>
839       *
840       * @return True if the per message operations can be applied over
841       *         the context.
842       */
843      boolean isProtReady();
844    
845      /**
846       * <p>Returns the confidentiality service state over the context. When
847       * issued before context establishment completes or when the isProtReady
848       * method returns "false", it returns the desired state, otherwise it
849       * will indicate the actual state over the established context.</p>
850       *
851       * @return True the confidentiality service state.
852       */
853      boolean getConfState();
854    
855      /**
856       * <p>Returns the integrity service state over the context. When issued
857       * before context establishment completes or when the isProtReady method
858       * returns "false", it returns the desired state, otherwise it will
859       * indicate the actual state over the established context.</p>
860       *
861       * @return The integrity service state.
862       */
863      boolean getIntegState();
864    
865      /**
866       * <p>Returns the context lifetime in seconds. When issued before context
867       * establishment completes or when the isProtReady method returns
868       * "false", it returns the desired lifetime, otherwise it will indicate
869       * the remaining lifetime for the context.</p>
870       *
871       * @return The lifetime.
872       */
873      int getLifetime();
874    
875      /**
876       * <p>Returns the name of the context initiator. This call is valid only
877       * after the context is fully established or the isProtReady method
878       * returns "true".  It is guaranteed to return an MN.</p>
879       *
880       * @return The name of the context initiator.
881       * @throws GSSException If this operation fails.
882       */
883      GSSName getSrcName() throws GSSException;
884    
885      /**
886       * <p>Returns the name of the context target (acceptor).  This call is
887       * valid only after the context is fully established or the isProtReady
888       * method returns "true".  It is guaranteed to return an MN.</p>
889       *
890       * @return The name of the context target.
891       * @throws GSSException If this operation fails.
892       */
893      GSSName getTargName() throws GSSException;
894    
895      /**
896       * <p>Returns the mechanism oid for this context. This method may be called
897       * before the context is fully established, but the mechanism returned
898       * may change on successive calls in negotiated mechanism case.</p>
899       *
900       * @return The mechanism OID.
901       * @throws GSSException If this operation fails.
902       */
903      Oid getMech() throws GSSException;
904    
905      /**
906       * <p>Returns the delegated credential object on the acceptor's side.
907       * To check for availability of delegated credentials call
908       * {@link #getDelegCredState()}. This call is only valid on fully
909       * established contexts.</p>
910       *
911       * @return The delegated credential object.
912       * @throws GSSException If this operation fails.
913       */
914      GSSCredential getDelegCred() throws GSSException;
915    
916      /**
917       * <p>Returns "true" if this is the initiator of the context. This call is
918       * only valid after the context creation process has started.</p>
919       *
920       * @return True if this is the initiator.
921       * @throws GSSException If this operation fails.
922       */
923      boolean isInitiator() throws GSSException;
924    }