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package org.ietf.jgss;

import java.io.InputStream;
import java.io.OutputStream;


This interface encapsulates the GSS-API security context and provides
the security services that are available over the context.  Security
contexts are established between peers using locally acquired
credentials.  Multiple contexts may exist simultaneously between a pair
of peers, using the same or different set of credentials.  GSS-API
functions in a manner independent of the underlying transport protocol
and depends on its calling application to transport the tokens that are
generated by the security context between the peers.

If the caller instantiates the context using the default
GSSManager instance, then the Kerberos v5 GSS-API mechanism
is guaranteed to be available for context establishment. This mechanism
is identified by the Oid "1.2.840.113554.1.2.2" and is defined in RFC
1964.

Before the context establishment phase is initiated, the context
initiator may request specific characteristics desired of the
established context. Not all underlying mechanisms support all
characteristics that a caller might desire. After the context is
established, the caller can check the actual characteristics and services
offered by that context by means of various query methods. When using
the Kerberos v5 GSS-API mechanism offered by the default
GSSManager instance, all optional services will be
available locally. They are mutual authentication, credential
delegation, confidentiality and integrity protection, and per-message
replay detection and sequencing. Note that in the GSS-API, message integrity
is a prerequisite for message confidentiality.
 The context establishment occurs in a loop where the initiator calls initSecContext and the acceptor calls 
acceptSecContext until the context is established. While in this loop the initSecContext and acceptSecContext
methods produce tokens that the application sends over to the peer. The
peer passes any such token as input to its acceptSecContext
or initSecContext as the case may be.
 During the context establishment phase, the isProtReady method may be called to determine if the context can be used for the per-message operations of wrap and getMIC. This allows applications to use per-message operations on contexts which aren't yet fully established.

After the context has been established or the isProtReady
method returns true, the query routines can be invoked to determine the actual characteristics and services of the established context. The application can also start using the per-message methods of wrap and getMIC to obtain cryptographic operations on application supplied data.
 When the context is no longer needed, the application should call dispose to release any system resources the context may be using.

A security context typically maintains sequencing and replay detection
information about the tokens it processes. Therefore, the sequence in
which any tokens are presented to this context for processing can be
important. Also note that none of the methods in this interface are
synchronized. Therefore, it is not advisable to share a
GSSContext among several threads unless some application
level synchronization is in place.

Finally, different mechanism providers might place different security
restrictions on using GSS-API contexts. These will be documented by the
mechanism provider. The application will need to ensure that it has the
appropriate permissions if such checks are made in the mechanism layer.

The example code presented below demonstrates the usage of the
GSSContext interface for the initiating peer.  Different
operations on the GSSContext object are presented,
including: object instantiation, setting of desired flags, context
establishment, query of actual context flags, per-message operations on
application data, and finally context deletion.

   // Create a context using default credentials
   // and the implementation specific default mechanism
   GSSManager manager ...
   GSSName targetName ...
   GSSContext context = manager.createContext(targetName, null, null,
                                          GSSContext.INDEFINITE_LIFETIME);
   // set desired context options prior to context establishment
   context.requestConf(true);
   context.requestMutualAuth(true);
   context.requestReplayDet(true);
   context.requestSequenceDet(true);
   // establish a context between peers
   byte []inToken = new byte[0];
   // Loop while there still is a token to be processed
   while (!context.isEstablished()) {
       byte[] outToken
           = context.initSecContext(inToken, 0, inToken.length);
       // send the output token if generated
       if (outToken != null)
           sendToken(outToken);
       if (!context.isEstablished()) {
           inToken = readToken();
   }
    // display context information
    System.out.println("Remaining lifetime in seconds = "
                                         + context.getLifetime());
    System.out.println("Context mechanism = " + context.getMech());
    System.out.println("Initiator = " + context.getSrcName());
    System.out.println("Acceptor = " + context.getTargName());
    if (context.getConfState())
            System.out.println("Confidentiality (i.e., privacy) is available");
    if (context.getIntegState())
            System.out.println("Integrity is available");
    // perform wrap on an application supplied message, appMsg,
    // using QOP = 0, and requesting privacy service
    byte [] appMsg ...
    MessageProp mProp = new MessageProp(0, true);
    byte []tok = context.wrap(appMsg, 0, appMsg.length, mProp);
    sendToken(tok);
    // release the local-end of the context
    context.dispose();



Author:Mayank Upadhyay
Since:1.4
/**
 * This interface encapsulates the GSS-API security context and provides
 * the security services that are available over the context.  Security
 * contexts are established between peers using locally acquired
 * credentials.  Multiple contexts may exist simultaneously between a pair
 * of peers, using the same or different set of credentials.  GSS-API
 * functions in a manner independent of the underlying transport protocol
 * and depends on its calling application to transport the tokens that are
 * generated by the security context between the peers.<p>
 *
 * If the caller instantiates the context using the default
 * <code>GSSManager</code> instance, then the Kerberos v5 GSS-API mechanism
 * is guaranteed to be available for context establishment. This mechanism
 * is identified by the Oid "1.2.840.113554.1.2.2" and is defined in RFC
 * 1964.<p>
 *
 * Before the context establishment phase is initiated, the context
 * initiator may request specific characteristics desired of the
 * established context. Not all underlying mechanisms support all
 * characteristics that a caller might desire. After the context is
 * established, the caller can check the actual characteristics and services
 * offered by that context by means of various query methods. When using
 * the Kerberos v5 GSS-API mechanism offered by the default
 * <code>GSSManager</code> instance, all optional services will be
 * available locally. They are mutual authentication, credential
 * delegation, confidentiality and integrity protection, and per-message
 * replay detection and sequencing. Note that in the GSS-API, message integrity
 * is a prerequisite for message confidentiality.<p>
 *
 * The context establishment occurs in a loop where the
 * initiator calls {@link #initSecContext(byte[], int, int) initSecContext}
 * and the acceptor calls {@link #acceptSecContext(byte[], int, int)
 * acceptSecContext} until the context is established. While in this loop
 * the <code>initSecContext</code> and <code>acceptSecContext</code>
 * methods produce tokens that the application sends over to the peer. The
 * peer passes any such token as input to its <code>acceptSecContext</code>
 * or <code>initSecContext</code> as the case may be.<p>
 *
 * During the context establishment phase, the {@link
 * #isProtReady() isProtReady} method may be called to determine if the
 * context can be used for the per-message operations of {@link
 * #wrap(byte[], int, int, MessageProp) wrap} and {@link #getMIC(byte[],
 * int, int, MessageProp) getMIC}.  This allows applications to use
 * per-message operations on contexts which aren't yet fully
 * established.<p>
 *
 * After the context has been established or the <code>isProtReady</code>
 * method returns <code>true</code>, the query routines can be invoked to
 * determine the actual characteristics and services of the established
 * context.  The application can also start using the per-message methods
 * of {@link #wrap(byte[], int, int, MessageProp) wrap} and
 * {@link #getMIC(byte[], int, int, MessageProp) getMIC} to obtain
 * cryptographic operations on application supplied data.<p>
 *
 * When the context is no longer needed, the application should call
 * {@link #dispose() dispose} to release any system resources the context
 * may be using.<p>
 *
 * A security context typically maintains sequencing and replay detection
 * information about the tokens it processes. Therefore, the sequence in
 * which any tokens are presented to this context for processing can be
 * important. Also note that none of the methods in this interface are
 * synchronized. Therefore, it is not advisable to share a
 * <code>GSSContext</code> among several threads unless some application
 * level synchronization is in place.<p>
 *
 * Finally, different mechanism providers might place different security
 * restrictions on using GSS-API contexts. These will be documented by the
 * mechanism provider. The application will need to ensure that it has the
 * appropriate permissions if such checks are made in the mechanism layer.<p>
 *
 * The example code presented below demonstrates the usage of the
 * <code>GSSContext</code> interface for the initiating peer.  Different
 * operations on the <code>GSSContext</code> object are presented,
 * including: object instantiation, setting of desired flags, context
 * establishment, query of actual context flags, per-message operations on
 * application data, and finally context deletion.
 *
 * <pre>
 *    // Create a context using default credentials
 *    // and the implementation specific default mechanism
 *    GSSManager manager ...
 *    GSSName targetName ...
 *    GSSContext context = manager.createContext(targetName, null, null,
 *                                           GSSContext.INDEFINITE_LIFETIME);
 *
 *    // set desired context options prior to context establishment
 *    context.requestConf(true);
 *    context.requestMutualAuth(true);
 *    context.requestReplayDet(true);
 *    context.requestSequenceDet(true);
 *
 *    // establish a context between peers
 *
 *    byte []inToken = new byte[0];
 *
 *    // Loop while there still is a token to be processed
 *
 *    while (!context.isEstablished()) {
 *
 *        byte[] outToken
 *            = context.initSecContext(inToken, 0, inToken.length);
 *
 *        // send the output token if generated
 *        if (outToken != null)
 *            sendToken(outToken);
 *
 *        if (!context.isEstablished()) {
 *            inToken = readToken();
 *    }
 *
 *     // display context information
 *     System.out.println("Remaining lifetime in seconds = "
 *                                          + context.getLifetime());
 *     System.out.println("Context mechanism = " + context.getMech());
 *     System.out.println("Initiator = " + context.getSrcName());
 *     System.out.println("Acceptor = " + context.getTargName());
 *
 *     if (context.getConfState())
 *             System.out.println("Confidentiality (i.e., privacy) is available");
 *
 *     if (context.getIntegState())
 *             System.out.println("Integrity is available");
 *
 *     // perform wrap on an application supplied message, appMsg,
 *     // using QOP = 0, and requesting privacy service
 *     byte [] appMsg ...
 *
 *     MessageProp mProp = new MessageProp(0, true);
 *
 *     byte []tok = context.wrap(appMsg, 0, appMsg.length, mProp);
 *
 *     sendToken(tok);
 *
 *     // release the local-end of the context
 *     context.dispose();
 *
 * </pre>
 *
 * @author Mayank Upadhyay
 * @since 1.4
 */
public interface GSSContext {

    
A lifetime constant representing the default context lifetime.  This
value is set to 0.

/**
     * A lifetime constant representing the default context lifetime.  This
     * value is set to 0.
     */
    public static final int DEFAULT_LIFETIME = 0;

    
A lifetime constant representing indefinite context lifetime. This value must is set to the maximum integer value in Java - Integer.MAX_VALUE. 
/**
     * A lifetime constant representing indefinite context lifetime.
     * This value must is set to the maximum integer value in Java -
     * {@link java.lang.Integer#MAX_VALUE Integer.MAX_VALUE}.
     */
    public static final int INDEFINITE_LIFETIME = Integer.MAX_VALUE;

    
Called by the context initiator to start the context creation
phase and process any tokens generated
by the peer's acceptSecContext method.
This method may return an output token which the application will need
to send to the peer for processing by its acceptSecContext method. The application can call 
isEstablished to determine if the context establishment phase is complete on this side of the context. A return value of false from isEstablished indicates that
more tokens are expected to be supplied to
initSecContext.  Upon completion of the context
establishment, the available context options may be queried through
the get methods.

Note that it is possible that the initSecContext method
return a token for the peer, and isEstablished return
true also. This indicates that the token needs to be sent
to the peer, but the local end of the context is now fully
established.
 Some mechanism providers might require that the caller be granted permission to initiate a security context. A failed permission check might cause a SecurityException to be thrown from this method. 
Params:
  • inputBuf – token generated by the peer. This parameter is ignored
on the first call since no token has been received from the peer.
  • offset – the offset within the inputBuf where the token begins.
  • len – the length of the token.
Throws:
Returns:a byte[] containing the token to be sent to the
peer. null indicates that no token is generated.
/**
     * Called by the context initiator to start the context creation
     * phase and process any tokens generated
     * by the peer's <code>acceptSecContext</code> method.
     * This method may return an output token which the application will need
     * to send to the peer for processing by its <code>acceptSecContext</code>
     * method. The application can call {@link #isEstablished()
     * isEstablished} to determine if the context establishment phase is
     * complete on this side of the context.  A return value of
     * <code>false</code> from <code>isEstablished</code> indicates that
     * more tokens are expected to be supplied to
     * <code>initSecContext</code>.  Upon completion of the context
     * establishment, the available context options may be queried through
     * the get methods.<p>
     *
     * Note that it is possible that the <code>initSecContext</code> method
     * return a token for the peer, and <code>isEstablished</code> return
     * <code>true</code> also. This indicates that the token needs to be sent
     * to the peer, but the local end of the context is now fully
     * established.<p>
     *
     * Some mechanism providers might require that the caller be granted
     * permission to initiate a security context. A failed permission check
     * might cause a {@link java.lang.SecurityException SecurityException}
     * to be thrown from this method.
     *
     * @return a byte[] containing the token to be sent to the
     * peer. <code>null</code> indicates that no token is generated.
     * @param inputBuf token generated by the peer. This parameter is ignored
     * on the first call since no token has been received from the peer.
     * @param offset the offset within the inputBuf where the token begins.
     * @param len the length of the token.
     *
     * @throws GSSException containing the following
     * major error codes:
     *   {@link GSSException#DEFECTIVE_TOKEN GSSException.DEFECTIVE_TOKEN},
     *   {@link GSSException#BAD_MIC GSSException.BAD_MIC},
     *   {@link GSSException#NO_CRED GSSException.NO_CRED},
     *   {@link GSSException#CREDENTIALS_EXPIRED
     *                                  GSSException.CREDENTIALS_EXPIRED},
     *   {@link GSSException#BAD_BINDINGS GSSException.BAD_BINDINGS},
     *   {@link GSSException#OLD_TOKEN GSSException.OLD_TOKEN},
     *   {@link GSSException#DUPLICATE_TOKEN GSSException.DUPLICATE_TOKEN},
     *   {@link GSSException#BAD_NAMETYPE GSSException.BAD_NAMETYPE},
     *   {@link GSSException#BAD_MECH GSSException.BAD_MECH},
     *   {@link GSSException#FAILURE GSSException.FAILURE}
     */
    public byte[] initSecContext(byte inputBuf[], int offset, int len)
        throws GSSException;

    
Called by the context initiator to start the context creation
phase and process any tokens generated
by the peer's acceptSecContext method using
streams. This method may write an output token to the
OutpuStream, which the application will
need to send to the peer for processing by its
acceptSecContext call. Typically, the application would ensure this by calling the flush method on an OutputStream that encapsulates the
connection between the two peers. The application can
determine if a token is written to the OutputStream from the return
value of this method. A return value of 0 indicates that no token was written. The application can call isEstablished to determine if the context establishment phase is complete on this side of the context. A return value of false from isEstablished
indicates that more tokens are expected to be supplied to
initSecContext.
Upon completion of the context establishment, the available context
options may be queried through the get methods.

Note that it is possible that the initSecContext method
return a token for the peer, and isEstablished return
true also. This indicates that the token needs to be sent
to the peer, but the local end of the context is now fully
established.
 The GSS-API authentication tokens contain a definitive start and end. This method will attempt to read one of these tokens per invocation, and may block on the stream if only part of the token is available. In all other respects this method is equivalent to the byte array based 
initSecContext.
 Some mechanism providers might require that the caller be granted permission to initiate a security context. A failed permission check might cause a SecurityException to be thrown from this method.

The following example code demonstrates how this method might be
used:

    InputStream is ...
    OutputStream os ...
    GSSContext context ...
    // Loop while there is still a token to be processed
    while (!context.isEstablished()) {
        context.initSecContext(is, os);
        // send output token if generated
        os.flush();
    }



Params:
  • inStream – an InputStream that contains the token generated by
the peer. This parameter is ignored on the first call since no token
has been or will be received from the peer at that point.
  • outStream – an OutputStream where the output token will be
written. During the final stage of context establishment, there may be
no bytes written.
Throws:
Returns:the number of bytes written to the OutputStream as part of the
token to be sent to the peer. A value of 0 indicates that no token
needs to be sent.
/**
     * Called by the context initiator to start the context creation
     * phase and process any tokens generated
     * by the peer's <code>acceptSecContext</code> method using
     * streams. This method may write an output token to the
     * <code>OutpuStream</code>, which the application will
     * need to send to the peer for processing by its
     * <code>acceptSecContext</code> call. Typically, the application would
     * ensure this by calling the  {@link java.io.OutputStream#flush() flush}
     * method on an <code>OutputStream</code> that encapsulates the
     * connection between the two peers. The application can
     * determine if a token is written to the OutputStream from the return
     * value of this method. A return value of <code>0</code> indicates that
     * no token was written. The application can call
     * {@link #isEstablished() isEstablished} to determine if the context
     * establishment phase is complete on this side of the context. A
     * return  value of <code>false</code> from <code>isEstablished</code>
     * indicates that more tokens are expected to be supplied to
     * <code>initSecContext</code>.
     * Upon completion of the context establishment, the available context
     * options may be queried through the get methods.<p>
     *
     * Note that it is possible that the <code>initSecContext</code> method
     * return a token for the peer, and <code>isEstablished</code> return
     * <code>true</code> also. This indicates that the token needs to be sent
     * to the peer, but the local end of the context is now fully
     * established.<p>
     *
     * The GSS-API authentication tokens contain a definitive start and
     * end. This method will attempt to read one of these tokens per
     * invocation, and may block on the stream if only part of the token is
     * available.  In all other respects this method is equivalent to the
     * byte array based {@link #initSecContext(byte[], int, int)
     * initSecContext}.<p>
     *
     * Some mechanism providers might require that the caller be granted
     * permission to initiate a security context. A failed permission check
     * might cause a {@link java.lang.SecurityException SecurityException}
     * to be thrown from this method.<p>
     *
     * The following example code demonstrates how this method might be
     * used:
     * <pre>
     *     InputStream is ...
     *     OutputStream os ...
     *     GSSContext context ...
     *
     *     // Loop while there is still a token to be processed
     *
     *     while (!context.isEstablished()) {
     *
     *         context.initSecContext(is, os);
     *
     *         // send output token if generated
     *         os.flush();
     *     }
     * </pre>
     *
     *
     * @return the number of bytes written to the OutputStream as part of the
     * token to be sent to the peer. A value of 0 indicates that no token
     * needs to be sent.
     * @param inStream an InputStream that contains the token generated by
     * the peer. This parameter is ignored on the first call since no token
     * has been or will be received from the peer at that point.
     * @param outStream an OutputStream where the output token will be
     * written. During the final stage of context establishment, there may be
     * no bytes written.
     *
     * @throws GSSException containing the following
     * major error codes:
     *   {@link GSSException#DEFECTIVE_TOKEN GSSException.DEFECTIVE_TOKEN},
     *   {@link GSSException#BAD_MIC GSSException.BAD_MIC},
     *   {@link GSSException#NO_CRED GSSException.NO_CRED},
     *   {@link GSSException#CREDENTIALS_EXPIRED GSSException.CREDENTIALS_EXPIRED},
     *   {@link GSSException#BAD_BINDINGS GSSException.BAD_BINDINGS},
     *   {@link GSSException#OLD_TOKEN GSSException.OLD_TOKEN},
     *   {@link GSSException#DUPLICATE_TOKEN GSSException.DUPLICATE_TOKEN},
     *   {@link GSSException#BAD_NAMETYPE GSSException.BAD_NAMETYPE},
     *   {@link GSSException#BAD_MECH GSSException.BAD_MECH},
     *   {@link GSSException#FAILURE GSSException.FAILURE}
     */
    public int initSecContext(InputStream inStream,
                              OutputStream outStream) throws GSSException;

    
Called by the context acceptor upon receiving a token from the
peer. This method may return an output token which the application
will need to send to the peer for further processing by its
initSecContext call.
 The application can call isEstablished to determine if the context establishment phase is complete for this peer. A return value of false from
isEstablished indicates that more tokens are expected to
be supplied to this method.    Upon completion of the context
establishment, the available context options may be queried through
the get methods.

Note that it is possible that acceptSecContext return a
token for the peer, and isEstablished return
true also.  This indicates that the token needs to be
sent to the peer, but the local end of the context is now fully
established.
 Some mechanism providers might require that the caller be granted permission to accept a security context. A failed permission check might cause a SecurityException to be thrown from this method.

The following example code demonstrates how this method might be
used:

    byte[] inToken;
    byte[] outToken;
    GSSContext context ...
    // Loop while there is still a token to be processed
    while (!context.isEstablished()) {
        inToken = readToken();
        outToken = context.acceptSecContext(inToken, 0,
                                            inToken.length);
        // send output token if generated
        if (outToken != null)
            sendToken(outToken);
    }



Params:
  • inToken – token generated by the peer.
  • offset – the offset within the inToken where the token begins.
  • len – the length of the token.
Throws:
Returns:a byte[] containing the token to be sent to the
peer. null indicates that no token is generated.
/**
     * Called by the context acceptor upon receiving a token from the
     * peer. This method may return an output token which the application
     * will need to send to the peer for further processing by its
     * <code>initSecContext</code> call.<p>
     *
     * The application can call {@link #isEstablished() isEstablished} to
     * determine if the context establishment phase is complete for this
     * peer.  A return value of <code>false</code> from
     * <code>isEstablished</code> indicates that more tokens are expected to
     * be supplied to this method.    Upon completion of the context
     * establishment, the available context options may be queried through
     * the get methods.<p>
     *
     * Note that it is possible that <code>acceptSecContext</code> return a
     * token for the peer, and <code>isEstablished</code> return
     * <code>true</code> also.  This indicates that the token needs to be
     * sent to the peer, but the local end of the context is now fully
     * established.<p>
     *
     * Some mechanism providers might require that the caller be granted
     * permission to accept a security context. A failed permission check
     * might cause a {@link java.lang.SecurityException SecurityException}
     * to be thrown from this method.<p>
     *
     * The following example code demonstrates how this method might be
     * used:
     * <pre>
     *     byte[] inToken;
     *     byte[] outToken;
     *     GSSContext context ...
     *
     *     // Loop while there is still a token to be processed
     *
     *     while (!context.isEstablished()) {
     *         inToken = readToken();
     *         outToken = context.acceptSecContext(inToken, 0,
     *                                             inToken.length);
     *         // send output token if generated
     *         if (outToken != null)
     *             sendToken(outToken);
     *     }
     * </pre>
     *
     *
     * @return a byte[] containing the token to be sent to the
     * peer. <code>null</code> indicates that no token is generated.
     * @param inToken token generated by the peer.
     * @param offset the offset within the inToken where the token begins.
     * @param len the length of the token.
     *
     * @throws GSSException containing the following
     * major error codes:
     *   {@link GSSException#DEFECTIVE_TOKEN GSSException.DEFECTIVE_TOKEN},
     *   {@link GSSException#BAD_MIC GSSException.BAD_MIC},
     *   {@link GSSException#NO_CRED GSSException.NO_CRED},
     *   {@link GSSException#CREDENTIALS_EXPIRED
     *                               GSSException.CREDENTIALS_EXPIRED},
     *   {@link GSSException#BAD_BINDINGS GSSException.BAD_BINDINGS},
     *   {@link GSSException#OLD_TOKEN GSSException.OLD_TOKEN},
     *   {@link GSSException#DUPLICATE_TOKEN GSSException.DUPLICATE_TOKEN},
     *   {@link GSSException#BAD_MECH GSSException.BAD_MECH},
     *   {@link GSSException#FAILURE GSSException.FAILURE}
     */
    public byte[] acceptSecContext(byte inToken[], int offset, int len)
        throws GSSException;

    
Called by the context acceptor to process a token from the peer using
streams.   It may write an output token to the
OutputStream, which the application
will need to send to the peer for processing by its
initSecContext method. Typically, the application would ensure this by calling the flush method on an OutputStream that encapsulates the connection between the two peers. The application can call isEstablished to determine if the context establishment phase is complete on this side of the context. A return value of false from isEstablished
indicates that more tokens are expected to be supplied to
acceptSecContext.
Upon completion of the context establishment, the available context
options may be queried through the get methods.

Note that it is possible that acceptSecContext return a
token for the peer, and isEstablished return
true also.  This indicates that the token needs to be
sent to the peer, but the local end of the context is now fully
established.
 The GSS-API authentication tokens contain a definitive start and end. This method will attempt to read one of these tokens per invocation, and may block on the stream if only part of the token is available. In all other respects this method is equivalent to the byte array based 
acceptSecContext.
 Some mechanism providers might require that the caller be granted permission to accept a security context. A failed permission check might cause a SecurityException to be thrown from this method.

The following example code demonstrates how this method might be
used:

    InputStream is ...
    OutputStream os ...
    GSSContext context ...
    // Loop while there is still a token to be processed
    while (!context.isEstablished()) {
        context.acceptSecContext(is, os);
        // send output token if generated
        os.flush();
    }



Params:
  • inStream – an InputStream that contains the token generated by
the peer.
  • outStream – an OutputStream where the output token will be
written. During the final stage of context establishment, there may be
no bytes written.
Throws:
/**
     * Called by the context acceptor to process a token from the peer using
     * streams.   It may write an output token to the
     * <code>OutputStream</code>, which the application
     * will need to send to the peer for processing by its
     * <code>initSecContext</code> method.  Typically, the application would
     * ensure this by calling the  {@link java.io.OutputStream#flush() flush}
     * method on an <code>OutputStream</code> that encapsulates the
     * connection between the two peers. The application can call
     * {@link #isEstablished() isEstablished} to determine if the context
     * establishment phase is complete on this side of the context. A
     * return  value of <code>false</code> from <code>isEstablished</code>
     * indicates that more tokens are expected to be supplied to
     * <code>acceptSecContext</code>.
     * Upon completion of the context establishment, the available context
     * options may be queried through the get methods.<p>
     *
     * Note that it is possible that <code>acceptSecContext</code> return a
     * token for the peer, and <code>isEstablished</code> return
     * <code>true</code> also.  This indicates that the token needs to be
     * sent to the peer, but the local end of the context is now fully
     * established.<p>
     *
     * The GSS-API authentication tokens contain a definitive start and
     * end. This method will attempt to read one of these tokens per
     * invocation, and may block on the stream if only part of the token is
     * available. In all other respects this method is equivalent to the byte
     * array based {@link #acceptSecContext(byte[], int, int)
     * acceptSecContext}.<p>
     *
     * Some mechanism providers might require that the caller be granted
     * permission to accept a security context. A failed permission check
     * might cause a {@link java.lang.SecurityException SecurityException}
     * to be thrown from this method.<p>
     *
     * The following example code demonstrates how this method might be
     * used:
     * <pre>
     *     InputStream is ...
     *     OutputStream os ...
     *     GSSContext context ...
     *
     *     // Loop while there is still a token to be processed
     *
     *     while (!context.isEstablished()) {
     *
     *         context.acceptSecContext(is, os);
     *
     *         // send output token if generated
     *         os.flush();
     *     }
     * </pre>
     *
     *
     * @param inStream an InputStream that contains the token generated by
     * the peer.
     * @param outStream an OutputStream where the output token will be
     * written. During the final stage of context establishment, there may be
     * no bytes written.
     *
     * @throws GSSException containing the following
     * major error codes:
     *   {@link GSSException#DEFECTIVE_TOKEN GSSException.DEFECTIVE_TOKEN},
     *   {@link GSSException#BAD_MIC GSSException.BAD_MIC},
     *   {@link GSSException#NO_CRED GSSException.NO_CRED},
     *   {@link GSSException#CREDENTIALS_EXPIRED
     *                           GSSException.CREDENTIALS_EXPIRED},
     *   {@link GSSException#BAD_BINDINGS GSSException.BAD_BINDINGS},
     *   {@link GSSException#OLD_TOKEN GSSException.OLD_TOKEN},
     *   {@link GSSException#DUPLICATE_TOKEN GSSException.DUPLICATE_TOKEN},
     *   {@link GSSException#BAD_MECH GSSException.BAD_MECH},
     *   {@link GSSException#FAILURE GSSException.FAILURE}
     */
    /* Missing return value in RFC. int should have been returned.
     * -----------------------------------------------------------
     *
     * The application can determine if a token is written to the
     * OutputStream from the return value of this method. A return value of
     * <code>0</code> indicates that no token was written.
     *
     * @return <strong>the number of bytes written to the
     * OutputStream as part of the token to be sent to the peer. A value of
     * 0 indicates that no token  needs to be
     * sent.</strong>
     */
    public void acceptSecContext(InputStream inStream,
                                 OutputStream outStream) throws GSSException;

    
Used during context establishment to determine the state of the
context.

Returns:true if this is a fully established context on
the caller's side and no more tokens are needed from the peer.
/**
     * Used during context establishment to determine the state of the
     * context.
     *
     * @return <code>true</code> if this is a fully established context on
     * the caller's side and no more tokens are needed from the peer.
     */
    public boolean isEstablished();

    
Releases any system resources and cryptographic information stored in
the context object and invalidates the context.

Throws:
/**
     * Releases any system resources and cryptographic information stored in
     * the context object and invalidates the context.
     *
     *
     * @throws GSSException containing the following
     * major error codes:
     *   {@link GSSException#FAILURE GSSException.FAILURE}
     */
    public void dispose() throws GSSException;

    
Used to determine limits on the size of the message
that can be passed to wrap. Returns the maximum
message size that, if presented to the wrap method with
the same confReq and qop parameters, will
result in an output token containing no more
than maxTokenSize bytes.

This call is intended for use by applications that communicate over
protocols that impose a maximum message size.  It enables the
application to fragment messages prior to applying protection.

GSS-API implementations are recommended but not required to detect
invalid QOP values when getWrapSizeLimit is called.
This routine guarantees only a maximum message size, not the
availability of specific QOP values for message protection.

Params:
  • qop – the level of protection wrap will be asked to provide.
  • confReq – true if wrap will be asked to provide
privacy, false  otherwise.
  • maxTokenSize – the desired maximum size of the token emitted by
wrap.
Throws:
Returns:the maximum size of the input token for the given output
token size
/**
     * Used to determine limits on the size of the message
     * that can be passed to <code>wrap</code>. Returns the maximum
     * message size that, if presented to the <code>wrap</code> method with
     * the same <code>confReq</code> and <code>qop</code> parameters, will
     * result in an output token containing no more
     * than <code>maxTokenSize</code> bytes.<p>
     *
     * This call is intended for use by applications that communicate over
     * protocols that impose a maximum message size.  It enables the
     * application to fragment messages prior to applying protection.<p>
     *
     * GSS-API implementations are recommended but not required to detect
     * invalid QOP values when <code>getWrapSizeLimit</code> is called.
     * This routine guarantees only a maximum message size, not the
     * availability of specific QOP values for message protection.
     *
     * @param qop the level of protection wrap will be asked to provide.
     * @param confReq <code>true</code> if wrap will be asked to provide
     * privacy, <code>false</code>  otherwise.
     * @param maxTokenSize the desired maximum size of the token emitted by
     * wrap.
     * @return the maximum size of the input token for the given output
     * token size
     *
     * @throws GSSException containing the following
     * major error codes:
     *   {@link GSSException#CONTEXT_EXPIRED GSSException.CONTEXT_EXPIRED},
     *   {@link GSSException#BAD_QOP GSSException.BAD_QOP},
     *   {@link GSSException#FAILURE GSSException.FAILURE}
     */
    public int getWrapSizeLimit(int qop, boolean confReq,
                                int maxTokenSize) throws GSSException;

    
Applies per-message security services over the established security
context. The method will return a token with the
application supplied data and a cryptographic MIC over it.
The data may be encrypted if confidentiality (privacy) was
requested.

The MessageProp object is instantiated by the application and used
to specify a QOP value which selects cryptographic algorithms, and a
privacy service to optionally encrypt the message.  The underlying
mechanism that is used in the call may not be able to provide the
privacy service.  It sets the actual privacy service that it does
provide in this MessageProp object which the caller should then
query upon return.  If the mechanism is not able to provide the
requested QOP, it throws a GSSException with the BAD_QOP code.

Since some application-level protocols may wish to use tokens
emitted by wrap to provide "secure framing", implementations should
support the wrapping of zero-length messages.

The application will be responsible for sending the token to the
peer.

Params:
  • inBuf – application data to be protected.
  • offset – the offset within the inBuf where the data begins.
  • len – the length of the data
  • msgProp – instance of MessageProp that is used by the
application to set the desired QOP and privacy state. Set the
desired QOP to 0 to request the default QOP. Upon return from this
method, this object will contain the actual privacy state that
was applied to the message by the underlying mechanism.
Throws:
Returns:a byte[] containing the token to be sent to the peer.
/**
     * Applies per-message security services over the established security
     * context. The method will return a token with the
     * application supplied data and a cryptographic MIC over it.
     * The data may be encrypted if confidentiality (privacy) was
     * requested.<p>
     *
     * The MessageProp object is instantiated by the application and used
     * to specify a QOP value which selects cryptographic algorithms, and a
     * privacy service to optionally encrypt the message.  The underlying
     * mechanism that is used in the call may not be able to provide the
     * privacy service.  It sets the actual privacy service that it does
     * provide in this MessageProp object which the caller should then
     * query upon return.  If the mechanism is not able to provide the
     * requested QOP, it throws a GSSException with the BAD_QOP code.<p>
     *
     * Since some application-level protocols may wish to use tokens
     * emitted by wrap to provide "secure framing", implementations should
     * support the wrapping of zero-length messages.<p>
     *
     * The application will be responsible for sending the token to the
     * peer.
     *
     * @param inBuf application data to be protected.
     * @param offset the offset within the inBuf where the data begins.
     * @param len the length of the data
     * @param msgProp instance of MessageProp that is used by the
     * application to set the desired QOP and privacy state. Set the
     * desired QOP to 0 to request the default QOP. Upon return from this
     * method, this object will contain the actual privacy state that
     * was applied to the message by the underlying mechanism.
     * @return a byte[] containing the token to be sent to the peer.
     *
     * @throws GSSException containing the following major error codes:
     *   {@link GSSException#CONTEXT_EXPIRED GSSException.CONTEXT_EXPIRED},
     *   {@link GSSException#BAD_QOP GSSException.BAD_QOP},
     *   {@link GSSException#FAILURE GSSException.FAILURE}
     */
    public byte[] wrap(byte inBuf[], int offset, int len,
                       MessageProp msgProp) throws GSSException;

    
Applies per-message security services over the established security context using streams. The method will return a token with the application supplied data and a cryptographic MIC over it. The data may be encrypted if confidentiality (privacy) was requested. This method is equivalent to the byte array based wrap method.
 The application will be responsible for sending the token to the peer. Typically, the application would ensure this by calling the flush method on an OutputStream that encapsulates the
connection between the two peers.

The MessageProp object is instantiated by the application and used
to specify a QOP value which selects cryptographic algorithms, and a
privacy service to optionally encrypt the message.  The underlying
mechanism that is used in the call may not be able to provide the
privacy service.  It sets the actual privacy service that it does
provide in this MessageProp object which the caller should then
query upon return.  If the mechanism is not able to provide the
requested QOP, it throws a GSSException with the BAD_QOP code.

Since some application-level protocols may wish to use tokens
emitted by wrap to provide "secure framing", implementations should
support the wrapping of zero-length messages.

Params:
  • inStream – an InputStream containing the application data to be
protected. All of the data that is available in
inStream is used.
  • outStream – an OutputStream to write the protected message
to.
  • msgProp – instance of MessageProp that is used by the
application to set the desired QOP and privacy state. Set the
desired QOP to 0 to request the default QOP. Upon return from this
method, this object will contain the actual privacy state that
was applied to the message by the underlying mechanism.
Throws:
/**
     * Applies per-message security services over the established security
     * context using streams. The method will return a
     * token with the application supplied data and a cryptographic MIC over it.
     * The data may be encrypted if confidentiality
     * (privacy) was requested. This method is equivalent to the byte array
     * based {@link #wrap(byte[], int, int, MessageProp) wrap} method.<p>
     *
     * The application will be responsible for sending the token to the
     * peer.  Typically, the application would
     * ensure this by calling the  {@link java.io.OutputStream#flush() flush}
     * method on an <code>OutputStream</code> that encapsulates the
     * connection between the two peers.<p>
     *
     * The MessageProp object is instantiated by the application and used
     * to specify a QOP value which selects cryptographic algorithms, and a
     * privacy service to optionally encrypt the message.  The underlying
     * mechanism that is used in the call may not be able to provide the
     * privacy service.  It sets the actual privacy service that it does
     * provide in this MessageProp object which the caller should then
     * query upon return.  If the mechanism is not able to provide the
     * requested QOP, it throws a GSSException with the BAD_QOP code.<p>
     *
     * Since some application-level protocols may wish to use tokens
     * emitted by wrap to provide "secure framing", implementations should
     * support the wrapping of zero-length messages.
     *
     * @param inStream an InputStream containing the application data to be
     * protected. All of the data that is available in
     * inStream is used.
     * @param outStream an OutputStream to write the protected message
     * to.
     * @param msgProp instance of MessageProp that is used by the
     * application to set the desired QOP and privacy state. Set the
     * desired QOP to 0 to request the default QOP. Upon return from this
     * method, this object will contain the actual privacy state that
     * was applied to the message by the underlying mechanism.
     *
     * @throws GSSException containing the following
     * major error codes:
     *   {@link GSSException#CONTEXT_EXPIRED GSSException.CONTEXT_EXPIRED},
     *   {@link GSSException#BAD_QOP GSSException.BAD_QOP},
     *   {@link GSSException#FAILURE GSSException.FAILURE}
     */
    public void wrap(InputStream inStream, OutputStream outStream,
                     MessageProp msgProp) throws GSSException;

    
Used to process tokens generated by the wrap method on
the other side of the context. The method will return the message
supplied by the peer application to its wrap call, while at the same
time verifying the embedded MIC for that message.

The MessageProp object is instantiated by the application and is
used by the underlying mechanism to return information to the caller
such as the QOP, whether confidentiality was applied to the message,
and other supplementary message state information.

Since some application-level protocols may wish to use tokens
emitted by wrap to provide "secure framing", implementations should
support the wrapping and unwrapping of zero-length messages.

Params:
  • inBuf – a byte array containing the wrap token received from
peer.
  • offset – the offset where the token begins.
  • len – the length of the token
  • msgProp – upon return from the method, this object will contain
the applied QOP, the privacy state of the message, and supplementary
information stating if the token was a duplicate, old, out of
sequence or arriving after a gap.
Throws:
Returns:a byte[] containing the message unwrapped from the input
token.
/**
     * Used to process tokens generated by the <code>wrap</code> method on
     * the other side of the context. The method will return the message
     * supplied by the peer application to its wrap call, while at the same
     * time verifying the embedded MIC for that message.<p>
     *
     * The MessageProp object is instantiated by the application and is
     * used by the underlying mechanism to return information to the caller
     * such as the QOP, whether confidentiality was applied to the message,
     * and other supplementary message state information.<p>
     *
     * Since some application-level protocols may wish to use tokens
     * emitted by wrap to provide "secure framing", implementations should
     * support the wrapping and unwrapping of zero-length messages.
     *
     * @param inBuf a byte array containing the wrap token received from
     * peer.
     * @param offset the offset where the token begins.
     * @param len the length of the token
     * @param msgProp upon return from the method, this object will contain
     * the applied QOP, the privacy state of the message, and supplementary
     * information stating if the token was a duplicate, old, out of
     * sequence or arriving after a gap.
     * @return a byte[] containing the message unwrapped from the input
     * token.
     *
     * @throws GSSException containing the following
     * major error codes:
     *   {@link GSSException#DEFECTIVE_TOKEN GSSException.DEFECTIVE_TOKEN},
     *   {@link GSSException#BAD_MIC GSSException.BAD_MIC},
     *   {@link GSSException#CONTEXT_EXPIRED GSSException.CONTEXT_EXPIRED},
     *   {@link GSSException#FAILURE GSSException.FAILURE}
     */
    public byte [] unwrap(byte[] inBuf, int offset, int len,
                          MessageProp msgProp) throws GSSException;

    
Uses streams to process tokens generated by the wrap
method on the other side of the context. The method will return the
message supplied by the peer application to its wrap call, while at
the same time verifying the embedded MIC for that message.

The MessageProp object is instantiated by the application and is
used by the underlying mechanism to return information to the caller
such as the QOP, whether confidentiality was applied to the message,
and other supplementary message state information.

Since some application-level protocols may wish to use tokens
emitted by wrap to provide "secure framing", implementations should
support the wrapping and unwrapping of zero-length messages.

The format of the input token that this method
reads is defined in the specification for the underlying mechanism that
will be used. This method will attempt to read one of these tokens per
invocation. If the mechanism token contains a definitive start and
end this method may block on the InputStream if only
part of the token is available. If the start and end of the token
are not definitive then the method will attempt to treat all
available bytes as part of the token.
 Other than the possible blocking behavior described above, this method is equivalent to the byte array based unwrap method. 
Params:
  • inStream – an InputStream that contains the wrap token generated
by the peer.
  • outStream – an OutputStream to write the application message
to.
  • msgProp – upon return from the method, this object will contain
the applied QOP, the privacy state of the message, and supplementary
information stating if the token was a duplicate, old, out of
sequence or arriving after a gap.
Throws:
/**
     * Uses streams to process tokens generated by the <code>wrap</code>
     * method on the other side of the context. The method will return the
     * message supplied by the peer application to its wrap call, while at
     * the same time verifying the embedded MIC for that message.<p>
     *
     * The MessageProp object is instantiated by the application and is
     * used by the underlying mechanism to return information to the caller
     * such as the QOP, whether confidentiality was applied to the message,
     * and other supplementary message state information.<p>
     *
     * Since some application-level protocols may wish to use tokens
     * emitted by wrap to provide "secure framing", implementations should
     * support the wrapping and unwrapping of zero-length messages.<p>
     *
     * The format of the input token that this method
     * reads is defined in the specification for the underlying mechanism that
     * will be used. This method will attempt to read one of these tokens per
     * invocation. If the mechanism token contains a definitive start and
     * end this method may block on the <code>InputStream</code> if only
     * part of the token is available. If the start and end of the token
     * are not definitive then the method will attempt to treat all
     * available bytes as part of the token.<p>
     *
     * Other than the possible blocking behavior described above, this
     * method is equivalent to the byte array based {@link #unwrap(byte[],
     * int, int, MessageProp) unwrap} method.
     *
     * @param inStream an InputStream that contains the wrap token generated
     * by the peer.
     * @param outStream an OutputStream to write the application message
     * to.
     * @param msgProp upon return from the method, this object will contain
     * the applied QOP, the privacy state of the message, and supplementary
     * information stating if the token was a duplicate, old, out of
     * sequence or arriving after a gap.
     *
     * @throws GSSException containing the following
     * major error codes:
     *   {@link GSSException#DEFECTIVE_TOKEN GSSException.DEFECTIVE_TOKEN},
     *   {@link GSSException#BAD_MIC GSSException.BAD_MIC},
     *   {@link GSSException#CONTEXT_EXPIRED GSSException.CONTEXT_EXPIRED},
     *   {@link GSSException#FAILURE GSSException.FAILURE}
     */
    public void unwrap(InputStream inStream, OutputStream outStream,
                       MessageProp msgProp) throws GSSException;

    
Returns a token containing a cryptographic Message Integrity Code
(MIC) for the supplied message,  for transfer to the peer
application.  Unlike wrap, which encapsulates the user message in the
returned token, only the message MIC is returned in the output
token.

Note that privacy can only be applied through the wrap call.

Since some application-level protocols may wish to use tokens emitted
by getMIC to provide "secure framing", implementations should support
derivation of MICs from zero-length messages.

Params:
  • inMsg – the message to generate the MIC over.
  • offset – offset within the inMsg where the message begins.
  • len – the length of the message
  • msgProp – an instance of MessageProp that is used
by the application to set the desired QOP.  Set the desired QOP to
0 in msgProp to request the default
QOP. Alternatively pass in null for msgProp
to request the default QOP.
Throws:
Returns:a byte[] containing the token to be sent to the peer.
/**
     * Returns a token containing a cryptographic Message Integrity Code
     * (MIC) for the supplied message,  for transfer to the peer
     * application.  Unlike wrap, which encapsulates the user message in the
     * returned token, only the message MIC is returned in the output
     * token.<p>
     *
     * Note that privacy can only be applied through the wrap call.<p>
     *
     * Since some application-level protocols may wish to use tokens emitted
     * by getMIC to provide "secure framing", implementations should support
     * derivation of MICs from zero-length messages.
     *
     * @param inMsg the message to generate the MIC over.
     * @param offset offset within the inMsg where the message begins.
     * @param len the length of the message
     * @param msgProp an instance of <code>MessageProp</code> that is used
     * by the application to set the desired QOP.  Set the desired QOP to
     * <code>0</code> in <code>msgProp</code> to request the default
     * QOP. Alternatively pass in <code>null</code> for <code>msgProp</code>
     * to request the default QOP.
     * @return a byte[] containing the token to be sent to the peer.
     *
     * @throws GSSException containing the following
     * major error codes:
     *   {@link GSSException#CONTEXT_EXPIRED GSSException.CONTEXT_EXPIRED},
     *   {@link GSSException#BAD_QOP GSSException.BAD_QOP},
     *   {@link GSSException#FAILURE GSSException.FAILURE}
     */
    public byte[] getMIC(byte []inMsg, int offset, int len,
                         MessageProp msgProp) throws GSSException;

    
Uses streams to produce a token containing a cryptographic MIC for the supplied message, for transfer to the peer application. Unlike wrap, which encapsulates the user message in the returned token, only the message MIC is produced in the output token. This method is equivalent to the byte array based getMIC method. Note that privacy can only be applied through the wrap call.

Since some application-level protocols may wish to use tokens emitted
by getMIC to provide "secure framing", implementations should support
derivation of MICs from zero-length messages.

Params:
  • inStream – an InputStream containing the message to generate the
MIC over. All of the data that is available in
inStream is used.
  • outStream – an OutputStream to write the output token to.
  • msgProp – an instance of MessageProp that is used
by the application to set the desired QOP.  Set the desired QOP to
0 in msgProp to request the default
QOP. Alternatively pass in null for msgProp
to request the default QOP.
Throws:
/**
     * Uses streams to produce a token containing a cryptographic MIC for
     * the supplied message, for transfer to the peer application.
     * Unlike wrap, which encapsulates the user message in the returned
     * token, only the message MIC is produced in the output token. This
     * method is equivalent to the byte array based {@link #getMIC(byte[],
     * int, int, MessageProp) getMIC} method.
     *
     * Note that privacy can only be applied through the wrap call.<p>
     *
     * Since some application-level protocols may wish to use tokens emitted
     * by getMIC to provide "secure framing", implementations should support
     * derivation of MICs from zero-length messages.
     *
     * @param inStream an InputStream containing the message to generate the
     * MIC over. All of the data that is available in
     * inStream is used.
     * @param outStream an OutputStream to write the output token to.
     * @param msgProp an instance of <code>MessageProp</code> that is used
     * by the application to set the desired QOP.  Set the desired QOP to
     * <code>0</code> in <code>msgProp</code> to request the default
     * QOP. Alternatively pass in <code>null</code> for <code>msgProp</code>
     * to request the default QOP.
     *
     * @throws GSSException containing the following
     * major error codes:
     *   {@link GSSException#CONTEXT_EXPIRED GSSException.CONTEXT_EXPIRED},
     *   {@link GSSException#BAD_QOP GSSException.BAD_QOP},
     *   {@link GSSException#FAILURE GSSException.FAILURE}
     */
    public void getMIC(InputStream inStream, OutputStream outStream,
                       MessageProp msgProp) throws GSSException;

    
Verifies the cryptographic MIC, contained in the token parameter,
over the supplied message.

The MessageProp object is instantiated by the application and is used
by the underlying mechanism to return information to the caller such
as the QOP indicating the strength of protection that was applied to
the message and other supplementary message state information.

Since some application-level protocols may wish to use tokens emitted
by getMIC to provide "secure framing", implementations should support
the calculation and verification of MICs over zero-length messages.

Params:
  • inToken – the token generated by peer's getMIC method.
  • tokOffset – the offset within the inToken where the token
begins.
  • tokLen – the length of the token.
  • inMsg – the application message to verify the cryptographic MIC
over.
  • msgOffset – the offset in inMsg where the message begins.
  • msgLen – the length of the message.
  • msgProp – upon return from the method, this object will contain
the applied QOP and supplementary information stating if the token
was a duplicate, old, out of sequence or arriving after a gap.
Throws:
/**
     * Verifies the cryptographic MIC, contained in the token parameter,
     * over the supplied message.<p>
     *
     * The MessageProp object is instantiated by the application and is used
     * by the underlying mechanism to return information to the caller such
     * as the QOP indicating the strength of protection that was applied to
     * the message and other supplementary message state information.<p>
     *
     * Since some application-level protocols may wish to use tokens emitted
     * by getMIC to provide "secure framing", implementations should support
     * the calculation and verification of MICs over zero-length messages.
     *
     * @param inToken the token generated by peer's getMIC method.
     * @param tokOffset the offset within the inToken where the token
     * begins.
     * @param tokLen the length of the token.
     * @param inMsg the application message to verify the cryptographic MIC
     * over.
     * @param msgOffset the offset in inMsg where the message begins.
     * @param msgLen the length of the message.
     * @param msgProp upon return from the method, this object will contain
     * the applied QOP and supplementary information stating if the token
     * was a duplicate, old, out of sequence or arriving after a gap.
     *
     * @throws GSSException containing the following
     * major error codes:
     *   {@link GSSException#DEFECTIVE_TOKEN GSSException.DEFECTIVE_TOKEN}
     *   {@link GSSException#BAD_MIC GSSException.BAD_MIC}
     *   {@link GSSException#CONTEXT_EXPIRED GSSException.CONTEXT_EXPIRED}
     *   {@link GSSException#FAILURE GSSException.FAILURE}
     */
    public void verifyMIC(byte[] inToken, int tokOffset, int tokLen,
                          byte[] inMsg, int msgOffset, int msgLen,
                          MessageProp msgProp) throws GSSException;

    
Uses streams to verify the cryptographic MIC, contained in the token parameter, over the supplied message. This method is equivalent to the byte array based verifyMIC method. The MessageProp object is instantiated by the application and is used by the underlying mechanism to return information to the caller such as the QOP indicating the strength of protection that was applied to the message and other supplementary message state information.

Since some application-level protocols may wish to use tokens emitted
by getMIC to provide "secure framing", implementations should support
the calculation and verification of MICs over zero-length messages.

The format of the input token that this method
reads is defined in the specification for the underlying mechanism that
will be used. This method will attempt to read one of these tokens per
invocation. If the mechanism token contains a definitive start and
end this method may block on the InputStream if only
part of the token is available. If the start and end of the token
are not definitive then the method will attempt to treat all
available bytes as part of the token.
 Other than the possible blocking behavior described above, this method is equivalent to the byte array based verifyMIC method. 
Params:
  • tokStream – an InputStream containing the token generated by the
peer's getMIC method.
  • msgStream – an InputStream containing the application message to
verify the cryptographic MIC over. All of the data
that is available in msgStream is used.
  • msgProp – upon return from the method, this object will contain
the applied QOP and supplementary information stating if the token
was a duplicate, old, out of sequence or arriving after a gap.
Throws:
/**
     * Uses streams to verify the cryptographic MIC, contained in the token
     * parameter, over the supplied message.  This method is equivalent to
     * the byte array based {@link #verifyMIC(byte[], int, int, byte[], int,
     * int, MessageProp) verifyMIC} method.
     *
     * The MessageProp object is instantiated by the application and is used
     * by the underlying mechanism to return information to the caller such
     * as the QOP indicating the strength of protection that was applied to
     * the message and other supplementary message state information.<p>
     *
     * Since some application-level protocols may wish to use tokens emitted
     * by getMIC to provide "secure framing", implementations should support
     * the calculation and verification of MICs over zero-length messages.<p>
     *
     * The format of the input token that this method
     * reads is defined in the specification for the underlying mechanism that
     * will be used. This method will attempt to read one of these tokens per
     * invocation. If the mechanism token contains a definitive start and
     * end this method may block on the <code>InputStream</code> if only
     * part of the token is available. If the start and end of the token
     * are not definitive then the method will attempt to treat all
     * available bytes as part of the token.<p>
     *
     * Other than the possible blocking behavior described above, this
     * method is equivalent to the byte array based {@link #verifyMIC(byte[],
     * int, int, byte[], int, int, MessageProp) verifyMIC} method.
     *
     * @param tokStream an InputStream containing the token generated by the
     * peer's getMIC method.
     * @param msgStream an InputStream containing the application message to
     * verify the cryptographic MIC over. All of the data
     * that is available in msgStream is used.
     * @param msgProp upon return from the method, this object will contain
     * the applied QOP and supplementary information stating if the token
     * was a duplicate, old, out of sequence or arriving after a gap.
     *
     * @throws GSSException containing the following
     * major error codes:
     *   {@link GSSException#DEFECTIVE_TOKEN GSSException.DEFECTIVE_TOKEN}
     *   {@link GSSException#BAD_MIC GSSException.BAD_MIC}
     *   {@link GSSException#CONTEXT_EXPIRED GSSException.CONTEXT_EXPIRED}
     *   {@link GSSException#FAILURE GSSException.FAILURE}
     */
    public void verifyMIC(InputStream tokStream, InputStream msgStream,
                          MessageProp msgProp) throws GSSException;

    
Exports this context so that another process may
import it.. Provided to support the sharing of work between
multiple processes. This routine will typically be used by the
context-acceptor, in an application where a single process receives
incoming connection requests and accepts security contexts over
them, then passes the established context to one or more other
processes for message exchange.
 This method deactivates the security context and creates an interprocess token which, when passed to GSSManager.createContext in another process, will re-activate the context in the second process. Only a single instantiation of a given context may be active at any one time; a subsequent attempt by a context exporter to access the exported security context will fail.

The implementation may constrain the set of processes by which the
interprocess token may be imported, either as a function of local
security policy, or as a result of implementation decisions.  For
example, some implementations may constrain contexts to be passed
only between processes that run under the same account, or which are
part of the same process group.

The interprocess token may contain security-sensitive information
(for example cryptographic keys).  While mechanisms are encouraged
to either avoid placing such sensitive information within
interprocess tokens, or to encrypt the token before returning it to
the application, in a typical GSS-API implementation this may not be
possible.  Thus the application must take care to protect the
interprocess token, and ensure that any process to which the token
is transferred is trustworthy. 
 Implementations are not required to support the inter-process transfer of security contexts. Calling the 
isTransferable method will indicate if the context object is transferable.
 Calling this method on a context that is not exportable will result in this exception being thrown with the error code 
GSSException.UNAVAILABLE. 
Throws:
See Also:
Returns:a byte[] containing the exported context
/**
     * Exports this context so that another process may
     * import it.. Provided to support the sharing of work between
     * multiple processes. This routine will typically be used by the
     * context-acceptor, in an application where a single process receives
     * incoming connection requests and accepts security contexts over
     * them, then passes the established context to one or more other
     * processes for message exchange.<p>
     *
     * This method deactivates the security context and creates an
     * interprocess token which, when passed to {@link
     * GSSManager#createContext(byte[]) GSSManager.createContext} in
     * another process, will re-activate the context in the second process.
     * Only a single instantiation of a given context may be active at any
     * one time; a subsequent attempt by a context exporter to access the
     * exported security context will fail.<p>
     *
     * The implementation may constrain the set of processes by which the
     * interprocess token may be imported, either as a function of local
     * security policy, or as a result of implementation decisions.  For
     * example, some implementations may constrain contexts to be passed
     * only between processes that run under the same account, or which are
     * part of the same process group.<p>
     *
     * The interprocess token may contain security-sensitive information
     * (for example cryptographic keys).  While mechanisms are encouraged
     * to either avoid placing such sensitive information within
     * interprocess tokens, or to encrypt the token before returning it to
     * the application, in a typical GSS-API implementation this may not be
     * possible.  Thus the application must take care to protect the
     * interprocess token, and ensure that any process to which the token
     * is transferred is trustworthy. <p>
     *
     * Implementations are not required to support the inter-process
     * transfer of security contexts.  Calling the {@link #isTransferable()
     * isTransferable} method will indicate if the context object is
     * transferable.<p>
     *
     * Calling this method on a context that
     * is not exportable will result in this exception being thrown with
     * the error code {@link GSSException#UNAVAILABLE
     * GSSException.UNAVAILABLE}.
     *
     * @return a byte[] containing the exported context
     * @see GSSManager#createContext(byte[])
     *
     * @throws GSSException containing the following
     * major error codes:
     *   {@link GSSException#UNAVAILABLE GSSException.UNAVAILABLE},
     *   {@link GSSException#CONTEXT_EXPIRED GSSException.CONTEXT_EXPIRED},
     *   {@link GSSException#NO_CONTEXT GSSException.NO_CONTEXT},
     *   {@link GSSException#FAILURE GSSException.FAILURE}
     */
    public byte [] export() throws GSSException;

    
Requests that mutual authentication be done during
context establishment. This request can only be made on the context
initiator's side and it has to be done prior to the first call to
initSecContext.
 Not all mechanisms support mutual authentication and some mechanisms might require mutual authentication even if the application doesn't. Therefore, the application should check to see if the request was honored with the 
getMutualAuthState method. 
Params:
  • state – a boolean value indicating whether mutual
authentication should be used or not.
Throws:
See Also:
/**
     * Requests that mutual authentication be done during
     * context establishment. This request can only be made on the context
     * initiator's side and it has to be done prior to the first call to
     * <code>initSecContext</code>.<p>
     *
     * Not all mechanisms support mutual authentication and some mechanisms
     * might require mutual authentication even if the application
     * doesn't. Therefore, the application should check to see if the
     * request was honored with the {@link #getMutualAuthState()
     * getMutualAuthState} method.
     *
     * @param state a boolean value indicating whether mutual
     * authentication should be used or not.
     * @see #getMutualAuthState()
     *
     * @throws GSSException containing the following
     * major error codes:
     *   {@link GSSException#FAILURE GSSException.FAILURE}
     */
    public void requestMutualAuth(boolean state) throws GSSException;

    
Requests that replay detection be enabled for the
per-message security services after context establishment. This
request can only be made on the context initiator's side and it has
to be done prior to the first call to
initSecContext. During context establishment replay
detection is not an option and is a function of the underlying
mechanism's capabilities.
 Not all mechanisms support replay detection and some mechanisms might require replay detection even if the application doesn't. Therefore, the application should check to see if the request was honored with the 
getReplayDetState method. If replay detection is enabled then the MessageProp.isDuplicateToken and MessageProp.isOldToken methods will return valid results for the MessageProp object that is passed
in to the unwrap method or the verifyMIC
method.

Params:
  • state – a boolean value indicating whether replay detection
should be enabled over the established context or not.
Throws:
See Also:
/**
     * Requests that replay detection be enabled for the
     * per-message security services after context establishment. This
     * request can only be made on the context initiator's side and it has
     * to be done prior to the first call to
     * <code>initSecContext</code>. During context establishment replay
     * detection is not an option and is a function of the underlying
     * mechanism's capabilities.<p>
     *
     * Not all mechanisms support replay detection and some mechanisms
     * might require replay detection even if the application
     * doesn't. Therefore, the application should check to see if the
     * request was honored with the {@link #getReplayDetState()
     * getReplayDetState} method. If replay detection is enabled then the
     * {@link MessageProp#isDuplicateToken() MessageProp.isDuplicateToken} and {@link
     * MessageProp#isOldToken() MessageProp.isOldToken} methods will return
     * valid results for the <code>MessageProp</code> object that is passed
     * in to the <code>unwrap</code> method or the <code>verifyMIC</code>
     * method.
     *
     * @param state a boolean value indicating whether replay detection
     * should be enabled over the established context or not.
     * @see #getReplayDetState()
     *
     * @throws GSSException containing the following
     * major error codes:
     *   {@link GSSException#FAILURE GSSException.FAILURE}
     */
    public void requestReplayDet(boolean state) throws GSSException;

    
Requests that sequence checking be enabled for the
per-message security services after context establishment. This
request can only be made on the context initiator's side and it has
to be done prior to the first call to
initSecContext. During context establishment sequence
checking is not an option and is a function of the underlying
mechanism's capabilities.
 Not all mechanisms support sequence checking and some mechanisms might require sequence checking even if the application doesn't. Therefore, the application should check to see if the request was honored with the 
getSequenceDetState method. If sequence checking is enabled then the MessageProp.isDuplicateToken, MessageProp.isOldToken, MessageProp.isUnseqToken, and MessageProp.isGapToken methods will return valid results for the MessageProp object that is passed
in to the unwrap method or the verifyMIC
method.

Params:
  • state – a boolean value indicating whether sequence checking
should be enabled over the established context or not.
Throws:
See Also:
/**
     * Requests that sequence checking be enabled for the
     * per-message security services after context establishment. This
     * request can only be made on the context initiator's side and it has
     * to be done prior to the first call to
     * <code>initSecContext</code>. During context establishment sequence
     * checking is not an option and is a function of the underlying
     * mechanism's capabilities.<p>
     *
     * Not all mechanisms support sequence checking and some mechanisms
     * might require sequence checking even if the application
     * doesn't. Therefore, the application should check to see if the
     * request was honored with the {@link #getSequenceDetState()
     * getSequenceDetState} method. If sequence checking is enabled then the
     * {@link MessageProp#isDuplicateToken() MessageProp.isDuplicateToken},
     * {@link MessageProp#isOldToken() MessageProp.isOldToken},
     * {@link MessageProp#isUnseqToken() MessageProp.isUnseqToken}, and
     * {@link MessageProp#isGapToken() MessageProp.isGapToken} methods will return
     * valid results for the <code>MessageProp</code> object that is passed
     * in to the <code>unwrap</code> method or the <code>verifyMIC</code>
     * method.
     *
     * @param state a boolean value indicating whether sequence checking
     * should be enabled over the established context or not.
     * @see #getSequenceDetState()
     *
     * @throws GSSException containing the following
     * major error codes:
     *   {@link GSSException#FAILURE GSSException.FAILURE}
     */
    public void requestSequenceDet(boolean state) throws GSSException;

    
Requests that the initiator's credentials be
delegated to the acceptor during context establishment. This
request can only be made on the context initiator's side and it has
to be done prior to the first call to
initSecContext. Not all mechanisms support credential delegation. Therefore, an application that desires delegation should check to see if the request was honored with the 
getCredDelegState method. If the application indicates that delegation must not be used, then the mechanism will honor the request and delegation will not occur. This is an exception to the general rule that a mechanism may enable a service even if it is not requested. 
Params:
  • state – a boolean value indicating whether the credentials
should be delegated or not.
Throws:
See Also:
/**
     * Requests that the initiator's credentials be
     * delegated to the acceptor during context establishment. This
     * request can only be made on the context initiator's side and it has
     * to be done prior to the first call to
     * <code>initSecContext</code>.
     *
     * Not all mechanisms support credential delegation. Therefore, an
     * application that desires delegation should check to see if the
     * request was honored with the {@link #getCredDelegState()
     * getCredDelegState} method. If the application indicates that
     * delegation must not be used, then the mechanism will honor the
     * request and delegation will not occur. This is an exception
     * to the general rule that a mechanism may enable a service even if it
     * is not requested.
     *
     * @param state a boolean value indicating whether the credentials
     * should be delegated or not.
     * @see #getCredDelegState()
     *
     * @throws GSSException containing the following
     * major error codes:
     *   {@link GSSException#FAILURE GSSException.FAILURE}
     */
    public void requestCredDeleg(boolean state) throws GSSException;

    
Requests that the initiator's identity not be
disclosed to the acceptor. This request can only be made on the
context initiator's side and it has to be done prior to the first
call to initSecContext. Not all mechanisms support anonymity for the initiator. Therefore, the application should check to see if the request was honored with the getAnonymityState method. 
Params:
  • state – a boolean value indicating if the initiator should
be authenticated to the acceptor as an anonymous principal.
Throws:
See Also:
/**
     * Requests that the initiator's identity not be
     * disclosed to the acceptor. This request can only be made on the
     * context initiator's side and it has to be done prior to the first
     * call to <code>initSecContext</code>.
     *
     * Not all mechanisms support anonymity for the initiator. Therefore, the
     * application should check to see if the request was honored with the
     * {@link #getAnonymityState() getAnonymityState} method.
     *
     * @param state a boolean value indicating if the initiator should
     * be authenticated to the acceptor as an anonymous principal.
     * @see #getAnonymityState
     *
     * @throws GSSException containing the following
     * major error codes:
     *   {@link GSSException#FAILURE GSSException.FAILURE}
     */
    public void requestAnonymity(boolean state) throws GSSException;

    
Requests that data confidentiality be enabled
for the wrap method. This request can only be made on
the context initiator's side and it has to be done prior to the
first call to initSecContext. Not all mechanisms support confidentiality and other mechanisms might enable it even if the application doesn't request it. The application may check to see if the request was honored with the getConfState method. If confidentiality is enabled, only then will the mechanism honor a request for privacy in the MessageProp object that is passed in to the wrap method.

Enabling confidentiality will also automatically enable
integrity.

Params:
  • state – a boolean value indicating whether confidentiality
should be enabled or not.
Throws:
See Also:
/**
     * Requests that data confidentiality be enabled
     * for the <code>wrap</code> method. This request can only be made on
     * the context initiator's side and it has to be done prior to the
     * first call to <code>initSecContext</code>.
     *
     * Not all mechanisms support confidentiality and other mechanisms
     * might enable it even if the application doesn't request
     * it. The application may check to see if the request was honored with
     * the {@link #getConfState() getConfState} method. If confidentiality
     * is enabled, only then will the mechanism honor a request for privacy
     * in the {@link MessageProp#MessageProp(int, boolean) MessageProp}
     * object that is passed in to the <code>wrap</code> method.<p>
     *
     * Enabling confidentiality will also automatically enable
     * integrity.
     *
     * @param state a boolean value indicating whether confidentiality
     * should be enabled or not.
     * @see #getConfState()
     * @see #getIntegState()
     * @see #requestInteg(boolean)
     * @see MessageProp
     *
     * @throws GSSException containing the following
     * major error codes:
     *   {@link GSSException#FAILURE GSSException.FAILURE}
     */
    public void requestConf(boolean state) throws GSSException;

    
Requests that data integrity be enabled
for the wrap and getMICmethods. This
request can only be made on the context initiator's side and it has
to be done prior to the first call to initSecContext. Not all mechanisms support integrity and other mechanisms might enable it even if the application doesn't request it. The application may check to see if the request was honored with the getIntegState method.

Disabling integrity will also automatically disable
confidentiality.

Params:
  • state – a boolean value indicating whether integrity
should be enabled or not.
Throws:
See Also:
/**
     * Requests that data integrity be enabled
     * for the <code>wrap</code> and <code>getMIC</code>methods. This
     * request can only be made on the context initiator's side and it has
     * to be done prior to the first call to <code>initSecContext</code>.
     *
     * Not all mechanisms support integrity and other mechanisms
     * might enable it even if the application doesn't request
     * it. The application may check to see if the request was honored with
     * the {@link #getIntegState() getIntegState} method.<p>
     *
     * Disabling integrity will also automatically disable
     * confidentiality.
     *
     * @param state a boolean value indicating whether integrity
     * should be enabled or not.
     * @see #getIntegState()
     *
     * @throws GSSException containing the following
     * major error codes:
     *   {@link GSSException#FAILURE GSSException.FAILURE}
     */
    public void requestInteg(boolean state) throws GSSException;

    
Requests a lifetime in seconds for the
context. This method can only be called on the context initiator's
side  and it has to be done prior to the first call to
initSecContext.
 The actual lifetime of the context will depend on the capabilities of the underlying mechanism and the application should call the getLifetime method to determine this. 
Params:
  • lifetime – the desired context lifetime in seconds. Use
INDEFINITE_LIFETIME to request an indefinite lifetime
and DEFAULT_LIFETIME to request a default lifetime.
Throws:
See Also:
/**
     * Requests a lifetime in seconds for the
     * context. This method can only be called on the context initiator's
     * side  and it has to be done prior to the first call to
     * <code>initSecContext</code>.<p>
     *
     * The actual lifetime of the context will depend on the capabilities of
     * the underlying mechanism and the application should call the {@link
     * #getLifetime() getLifetime} method to determine this.
     *
     * @param lifetime the desired context lifetime in seconds. Use
     * <code>INDEFINITE_LIFETIME</code> to request an indefinite lifetime
     * and <code>DEFAULT_LIFETIME</code> to request a default lifetime.
     * @see #getLifetime()
     *
     * @throws GSSException containing the following
     * major error codes:
     *   {@link GSSException#FAILURE GSSException.FAILURE}
     */
    public void requestLifetime(int lifetime) throws GSSException;

    
Sets the channel bindings to be used during context
establishment. This method can be called on both
the context initiator's and the context acceptor's side, but it must
be called before context establishment begins. This means that an
initiator must call it before the first call to
initSecContext and the acceptor must call it before the
first call to acceptSecContext.

Params:
  • cb – the channel bindings to use.
Throws:
/**
     * Sets the channel bindings to be used during context
     * establishment. This method can be called on both
     * the context initiator's and the context acceptor's side, but it must
     * be called before context establishment begins. This means that an
     * initiator must call it before the first call to
     * <code>initSecContext</code> and the acceptor must call it before the
     * first call to <code>acceptSecContext</code>.
     *
     * @param cb the channel bindings to use.
     *
     * @throws GSSException containing the following
     * major error codes:
     *   {@link GSSException#FAILURE GSSException.FAILURE}
     */
    public void setChannelBinding(ChannelBinding cb) throws GSSException;

    
Determines if credential delegation is enabled on this context. It can be called by both the context initiator and the context acceptor. For a definitive answer this method must be called only after context establishment is complete. Note that if an initiator requests that delegation not be allowed the requestCredDeleg method will honor that request and this method will return false on the
initiator's side from that point onwards.

See Also:
Returns:true if delegation is enabled, false otherwise.
/**
     * Determines if credential delegation is enabled on
     * this context. It can be called by both the context initiator and the
     * context acceptor. For a definitive answer this method must be
     * called only after context establishment is complete. Note that if an
     * initiator requests that delegation not be allowed the {@link
     * #requestCredDeleg(boolean) requestCredDeleg} method will honor that
     * request and this method will return <code>false</code> on the
     * initiator's side from that point onwards.
     *
     * @return true if delegation is enabled, false otherwise.
     * @see #requestCredDeleg(boolean)
     */
    public boolean getCredDelegState();

    
Determines if mutual authentication is enabled on
this context. It can be called by both the context initiator and the
context acceptor. For a definitive answer this method must be
called only after context establishment is complete. An initiator
that requests mutual authentication can call this method after
context completion and dispose the context if its request was not
honored.

See Also:
Returns:true if mutual authentication is enabled, false otherwise.
/**
     * Determines if mutual authentication is enabled on
     * this context. It can be called by both the context initiator and the
     * context acceptor. For a definitive answer this method must be
     * called only after context establishment is complete. An initiator
     * that requests mutual authentication can call this method after
     * context completion and dispose the context if its request was not
     * honored.
     *
     * @return true if mutual authentication is enabled, false otherwise.
     * @see #requestMutualAuth(boolean)
     */
    public boolean getMutualAuthState();

    
Determines if replay detection is enabled for the
per-message security services from this context. It can be called by
both the context initiator and the context acceptor. For a
definitive answer this method must be called only after context
establishment is complete. An initiator that requests replay
detection can call this method after context completion and
dispose the context if its request was not honored.

See Also:
Returns:true if replay detection is enabled, false otherwise.
/**
     * Determines if replay detection is enabled for the
     * per-message security services from this context. It can be called by
     * both the context initiator and the context acceptor. For a
     * definitive answer this method must be called only after context
     * establishment is complete. An initiator that requests replay
     * detection can call this method after context completion and
     * dispose the context if its request was not honored.
     *
     * @return true if replay detection is enabled, false otherwise.
     * @see #requestReplayDet(boolean)
     */
    public boolean getReplayDetState();

    
Determines if sequence checking is enabled for the
per-message security services from this context. It can be called by
both the context initiator and the context acceptor. For a
definitive answer this method must be called only after context
establishment is complete. An initiator that requests sequence
checking can call this method after context completion and
dispose the context if its request was not honored.

See Also:
Returns:true if sequence checking is enabled, false otherwise.
/**
     * Determines if sequence checking is enabled for the
     * per-message security services from this context. It can be called by
     * both the context initiator and the context acceptor. For a
     * definitive answer this method must be called only after context
     * establishment is complete. An initiator that requests sequence
     * checking can call this method after context completion and
     * dispose the context if its request was not honored.
     *
     * @return true if sequence checking is enabled, false otherwise.
     * @see #requestSequenceDet(boolean)
     */
    public boolean getSequenceDetState();

    
Determines if the context initiator is
anonymously authenticated to the context acceptor. It can be called by
both the context initiator and the context acceptor, and at any
time. On the initiator side, a call to this method determines
if the identity of the initiator has been disclosed in any of the
context establishment tokens that might have been generated thus far
by initSecContext. An initiator that absolutely must be
authenticated anonymously should call this method after each call to
initSecContext to determine if the generated token
should be sent to the peer or the context aborted. On the
acceptor side, a call to this method determines if any of the tokens
processed by acceptSecContext thus far have divulged
the identity of the initiator.

See Also:
Returns:true if the context initiator is still anonymous, false
otherwise.
/**
     * Determines if the context initiator is
     * anonymously authenticated to the context acceptor. It can be called by
     * both the context initiator and the context acceptor, and at any
     * time. <strong>On the initiator side, a call to this method determines
     * if the identity of the initiator has been disclosed in any of the
     * context establishment tokens that might have been generated thus far
     * by <code>initSecContext</code>. An initiator that absolutely must be
     * authenticated anonymously should call this method after each call to
     * <code>initSecContext</code> to determine if the generated token
     * should be sent to the peer or the context aborted.</strong> On the
     * acceptor side, a call to this method determines if any of the tokens
     * processed by <code>acceptSecContext</code> thus far have divulged
     * the identity of the initiator.
     *
     * @return true if the context initiator is still anonymous, false
     * otherwise.
     * @see #requestAnonymity(boolean)
     */
    public boolean getAnonymityState();

    
Determines if the context is transferable to other processes through the use of the export method. This call is only valid on fully established contexts. 
Throws:
Returns:true if this context can be exported, false otherwise.
/**
     * Determines if the context is transferable to other processes
     * through the use of the {@link #export() export} method.  This call
     * is only valid on fully established contexts.
     *
     * @return true if this context can be exported, false otherwise.
     *
     * @throws GSSException containing the following
     * major error codes:
     *   {@link GSSException#FAILURE GSSException.FAILURE}
     */
    public boolean isTransferable() throws GSSException;

    
Determines if the context is ready for per message operations to be
used over it.  Some mechanisms may allow the usage of the
per-message operations before the context is fully established.

Returns:true if methods like wrap, unwrap,
getMIC, and verifyMIC can be used with
this context at the current stage of context establishment, false
otherwise.
/**
     * Determines if the context is ready for per message operations to be
     * used over it.  Some mechanisms may allow the usage of the
     * per-message operations before the context is fully established.
     *
     * @return true if methods like <code>wrap</code>, <code>unwrap</code>,
     * <code>getMIC</code>, and <code>verifyMIC</code> can be used with
     * this context at the current stage of context establishment, false
     * otherwise.
     */
    public boolean isProtReady();

    
Determines if data confidentiality is available over the context. This method can be called by both the context initiator and the context acceptor, but only after one of isProtReady or 
isEstablished return true. If this method returns
true, so will 
getIntegState 
See Also:
Returns:true if confidentiality services are available, false
otherwise.
/**
     * Determines if data confidentiality is available
     * over the context. This method can be called by both the context
     * initiator and the context acceptor, but only after one of {@link
     * #isProtReady() isProtReady} or {@link #isEstablished()
     * isEstablished} return <code>true</code>. If this method returns
     * <code>true</code>, so will {@link #getIntegState()
     * getIntegState}
     *
     * @return true if confidentiality services are available, false
     * otherwise.
     * @see #requestConf(boolean)
     */
    public boolean getConfState();

    
Determines if data integrity is available over the context. This method can be called by both the context initiator and the context acceptor, but only after one of isProtReady or 
isEstablished return true. This method will always
return true if getConfState returns true. 
See Also:
Returns:true if integrity services are available, false otherwise.
/**
     * Determines if data integrity is available
     * over the context. This method can be called by both the context
     * initiator and the context acceptor, but only after one of {@link
     * #isProtReady() isProtReady} or {@link #isEstablished()
     * isEstablished} return <code>true</code>. This method will always
     * return <code>true</code> if {@link #getConfState() getConfState}
     * returns true.
     *
     * @return true if integrity services are available, false otherwise.
     * @see #requestInteg(boolean)
     */
    public boolean getIntegState();

    
Determines what the remaining lifetime for this context is. It can be called by both the context initiator and the context acceptor, but for a definitive answer it should be called only after isEstablished returns true. 
See Also:
Returns:the remaining lifetime in seconds
/**
     * Determines what the remaining lifetime for this
     * context is. It can be called by both the context initiator and the
     * context acceptor, but for a definitive answer it should be called
     * only after {@link #isEstablished() isEstablished} returns
     * true.
     *
     * @return the remaining lifetime in seconds
     * @see #requestLifetime(int)
     */
    public int getLifetime();

    
Returns the name of the context initiator. This call is valid only after one of isProtReady or isEstablished return true.

Throws:
See Also:
Returns:a GSSName that is an MN containing the name of the context
initiator.
/**
     * Returns the name of the context initiator. This call is valid only
     * after one of {@link #isProtReady() isProtReady} or {@link
     * #isEstablished() isEstablished} return <code>true</code>.
     *
     * @return a GSSName that is an MN containing the name of the context
     * initiator.
     * @see GSSName
     *
     * @throws GSSException containing the following
     * major error codes:
     *   {@link GSSException#FAILURE GSSException.FAILURE}
     */
    public GSSName getSrcName() throws GSSException;

    
Returns the name of the context acceptor. This call is valid only after one of isProtReady or isEstablished return true.

Throws:
Returns:a GSSName that is an MN containing the name of the context
acceptor.
/**
     * Returns the name of the context acceptor. This call is valid only
     * after one of {@link #isProtReady() isProtReady} or {@link
     * #isEstablished() isEstablished} return <code>true</code>.
     *
     * @return a GSSName that is an MN containing the name of the context
     * acceptor.
     *
     * @throws GSSException containing the following
     * major error codes:
     *   {@link GSSException#FAILURE GSSException.FAILURE}
     */
    public GSSName getTargName() throws GSSException;

    
Determines what mechanism is being used for this
context. This method may be called before the context is fully
established, but the mechanism returned may change on successive
calls in the negotiated mechanism case.

Throws:
Returns:the Oid of the mechanism being used
/**
     * Determines what mechanism is being used for this
     * context. This method may be called before the context is fully
     * established, but the mechanism returned may change on successive
     * calls in the negotiated mechanism case.
     *
     * @return the Oid of the mechanism being used
     *
     * @throws GSSException containing the following
     * major error codes:
     *   {@link GSSException#FAILURE GSSException.FAILURE}
     */
    public Oid getMech() throws GSSException;

    
Obtains the credentials delegated by the context initiator to the context acceptor. It should be called only on the context acceptor's side, and once the context is fully established. The caller can use the method getCredDelegState to determine if there are any delegated credentials. 
Throws:
Returns:a GSSCredential containing the initiator's delegated
credentials, or null is no credentials
were delegated.
/**
     * Obtains the credentials delegated by the context
     * initiator to the context acceptor. It should be called only on the
     * context acceptor's side, and once the context is fully
     * established. The caller can use the method {@link
     * #getCredDelegState() getCredDelegState} to determine if there are
     * any delegated credentials.
     *
     * @return a GSSCredential containing the initiator's delegated
     * credentials, or <code>null</code> is no credentials
     * were delegated.
     *
     * @throws GSSException containing the following
     * major error codes:
     *   {@link GSSException#FAILURE GSSException.FAILURE}
     */
    public GSSCredential getDelegCred() throws GSSException;

    
Determines if this is the context initiator. This
can be called on both the context initiator's and context acceptor's
side.

Throws:
Returns:true if this is the context initiator, false if it is the
context acceptor.
/**
     * Determines if this is the context initiator. This
     * can be called on both the context initiator's and context acceptor's
     * side.
     *
     * @return true if this is the context initiator, false if it is the
     * context acceptor.
     *
     * @throws GSSException containing the following
     * major error codes:
     *   {@link GSSException#FAILURE GSSException.FAILURE}
     */
    public boolean isInitiator() throws GSSException;
}