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package org.ietf.jgss;


This interface encapsulates the GSS-API credentials for an entity.  A
credential contains all the necessary cryptographic information to
enable the creation of a context on behalf of the entity that it
represents.  It may contain multiple, distinct, mechanism specific
credential elements, each containing information for a specific
security mechanism, but all referring to the same entity. A credential
may be used to perform context initiation, acceptance, or both.

Credentials are instantiated using one of the
createCredential methods in the 
GSSManager class. GSS-API credential creation is not intended to provide a "login to the network" function, as such a function would involve the creation of new credentials rather than merely acquiring a handle to existing credentials. The section on credential
acquisition in the package level description describes
how existing credentials are acquired in the Java platform. GSS-API
implementations must impose a local access-control policy on callers to
prevent unauthorized callers from acquiring credentials to which they
are not entitled. 
 Applications will create a credential object passing the desired parameters. The application can then use the query methods to obtain specific information about the instantiated credential object. When the credential is no longer needed, the application should call the dispose method to release any resources held by the credential object and to destroy any cryptographically sensitive information.

This example code demonstrates the creation of a GSSCredential
implementation for a specific entity, querying of its fields, and its
release when it is no longer needed:


   GSSManager manager = GSSManager.getInstance();
   // start by creating a name object for the entity
   GSSName name = manager.createName("myusername", GSSName.NT_USER_NAME);
   // now acquire credentials for the entity
   GSSCredential cred = manager.createCredential(name,
                   GSSCredential.ACCEPT_ONLY);
   // display credential information - name, remaining lifetime,
   // and the mechanisms it has been acquired over
   System.out.println(cred.getName().toString());
   System.out.println(cred.getRemainingLifetime());
   Oid [] mechs = cred.getMechs();
   if (mechs != null) {
           for (int i = 0; i < mechs.length; i++)
                   System.out.println(mechs[i].toString());
   }
   // release system resources held by the credential
   cred.dispose();



Author:Mayank Upadhyay
See Also:
Since:1.4
/**
 * This interface encapsulates the GSS-API credentials for an entity.  A
 * credential contains all the necessary cryptographic information to
 * enable the creation of a context on behalf of the entity that it
 * represents.  It may contain multiple, distinct, mechanism specific
 * credential elements, each containing information for a specific
 * security mechanism, but all referring to the same entity. A credential
 * may be used to perform context initiation, acceptance, or both.<p>
 *
 * Credentials are instantiated using one of the
 * <code>createCredential</code> methods in the {@link GSSManager
 * GSSManager} class. GSS-API credential creation is not
 * intended to provide a "login to the network" function, as such a
 * function would involve the creation of new credentials rather than
 * merely acquiring a handle to existing credentials. The
 * <a href=package-summary.html#useSubjectCredsOnly>section on credential
 * acquisition</a> in the package level description describes
 * how existing credentials are acquired in the Java platform. GSS-API
 * implementations must impose a local access-control policy on callers to
 * prevent unauthorized callers from acquiring credentials to which they
 * are not entitled. <p>
 *
 * Applications will create a credential object passing the desired
 * parameters.  The application can then use the query methods to obtain
 * specific information about the instantiated credential object.
 * When the credential is no longer needed, the application should call
 * the {@link #dispose() dispose} method to release any resources held by
 * the credential object and to destroy any cryptographically sensitive
 * information.<p>
 *
 * This example code demonstrates the creation of a GSSCredential
 * implementation for a specific entity, querying of its fields, and its
 * release when it is no longer needed:<p>
 * <pre>
 *    GSSManager manager = GSSManager.getInstance();
 *
 *    // start by creating a name object for the entity
 *    GSSName name = manager.createName("myusername", GSSName.NT_USER_NAME);
 *
 *    // now acquire credentials for the entity
 *    GSSCredential cred = manager.createCredential(name,
 *                    GSSCredential.ACCEPT_ONLY);
 *
 *    // display credential information - name, remaining lifetime,
 *    // and the mechanisms it has been acquired over
 *    System.out.println(cred.getName().toString());
 *    System.out.println(cred.getRemainingLifetime());
 *
 *    Oid [] mechs = cred.getMechs();
 *    if (mechs != null) {
 *            for (int i = 0; i < mechs.length; i++)
 *                    System.out.println(mechs[i].toString());
 *    }
 *
 *    // release system resources held by the credential
 *    cred.dispose();
 * </pre>
 *
 * @see GSSManager#createCredential(int)
 * @see GSSManager#createCredential(GSSName, int, Oid, int)
 * @see GSSManager#createCredential(GSSName, int, Oid[], int)
 * @see #dispose()
 *
 * @author Mayank Upadhyay
 * @since 1.4
 */
public interface GSSCredential extends Cloneable{

    
Credential usage flag requesting that it be usable
for both context initiation and acceptance.

/**
     * Credential usage flag requesting that it be usable
     * for both context initiation and acceptance.
     *
     */
    public static final int INITIATE_AND_ACCEPT = 0;


    
Credential usage flag requesting that it be usable
for context initiation only.

/**
     * Credential usage flag requesting that it be usable
     * for context initiation only.
     *
     */
    public static final int INITIATE_ONLY = 1;


    
Credential usage flag requesting that it be usable
for context acceptance only.

/**
     * Credential usage flag requesting that it be usable
     * for context acceptance only.
     *
     */
    public static final int ACCEPT_ONLY = 2;


    
A lifetime constant representing the default credential lifetime. This
value it set to 0.

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

    
A lifetime constant representing indefinite credential lifetime. This value must is set to the maximum integer value in Java - Integer.MAX_VALUE. 
/**
     * A lifetime constant representing indefinite credential 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;

    
Releases any sensitive information that the GSSCredential object may
be containing.  Applications should call this method as soon as the
credential is no longer needed to minimize the time any sensitive
information is maintained.

Throws:
/**
     * Releases any sensitive information that the GSSCredential object may
     * be containing.  Applications should call this method as soon as the
     * credential is no longer needed to minimize the time any sensitive
     * information is maintained.
     *
     * @throws GSSException containing the following
     * major error codes:
     *         {@link GSSException#FAILURE GSSException.FAILURE}
     */
    public void dispose() throws GSSException;

    
 Retrieves the name of the entity that the credential asserts.

Throws:
Returns:a GSSName representing the entity
/**
     *  Retrieves the name of the entity that the credential asserts.
     *
     * @return a GSSName representing the entity
     *
     * @throws GSSException containing the following
     * major error codes:
     *         {@link GSSException#FAILURE GSSException.FAILURE}
     */
    public GSSName getName() throws GSSException;

    
Retrieves a Mechanism Name of the entity that the credential asserts. This is equivalent to calling canonicalize on the value returned by the other form of getName. 
Params:
  • mech – the Oid of the mechanism for which the Mechanism Name
should be returned.
Throws:
Returns:a GSSName representing the entity canonicalized for the
desired mechanism
/**
     * Retrieves a Mechanism Name of the entity that the credential
     * asserts. This is equivalent to calling {@link
     * GSSName#canonicalize(Oid) canonicalize} on the value returned by
     * the other form of {@link #getName() getName}.
     *
     * @param mech the Oid of the mechanism for which the Mechanism Name
     * should be returned.
     * @return a GSSName representing the entity canonicalized for the
     * desired mechanism
     *
     * @throws GSSException containing the following
     * major error codes:
     *         {@link GSSException#BAD_MECH GSSException.BAD_MECH},
     *         {@link GSSException#FAILURE GSSException.FAILURE}
     */
    public GSSName getName(Oid mech) throws GSSException;

    
Returns the remaining lifetime in seconds for a credential.  The
remaining lifetime is the minimum lifetime amongst all of the underlying
mechanism specific credential elements.

Throws:
See Also:
Returns:the minimum remaining lifetime in seconds for this credential. A return value of 
INDEFINITE_LIFETIME indicates that the credential does not expire. A return value of 0 indicates that the credential is already expired.
/**
     * Returns the remaining lifetime in seconds for a credential.  The
     * remaining lifetime is the minimum lifetime amongst all of the underlying
     * mechanism specific credential elements.
     *
     * @return the minimum remaining lifetime in seconds for this
     * credential. A return value of {@link #INDEFINITE_LIFETIME
     * INDEFINITE_LIFETIME} indicates that the credential does
     * not expire. A return value of 0 indicates that the credential is
     * already expired.
     *
     * @see #getRemainingInitLifetime(Oid)
     * @see #getRemainingAcceptLifetime(Oid)
     *
     * @throws GSSException containing the following
     * major error codes:
     *         {@link GSSException#FAILURE GSSException.FAILURE}
     */
    public int getRemainingLifetime() throws GSSException;

    
Returns the lifetime in seconds for the credential to remain capable
of initiating security contexts using the specified mechanism. This
method queries the initiator credential element that belongs to the
specified mechanism.

Params:
  • mech – the Oid of the mechanism whose initiator credential element
should be queried.
Throws:
Returns:the number of seconds remaining in the life of this credential element. A return value of 
INDEFINITE_LIFETIME indicates that the credential element does not expire. A return value of 0 indicates that the credential element is already expired.
/**
     * Returns the lifetime in seconds for the credential to remain capable
     * of initiating security contexts using the specified mechanism. This
     * method queries the initiator credential element that belongs to the
     * specified mechanism.
     *
     * @return the number of seconds remaining in the life of this credential
     * element. A return value of {@link #INDEFINITE_LIFETIME
     * INDEFINITE_LIFETIME} indicates that the credential element does not
     * expire.  A return value of 0 indicates that the credential element is
     * already expired.
     *
     * @param mech the Oid of the mechanism whose initiator credential element
     * should be queried.
     *
     * @throws GSSException containing the following
     * major error codes:
     *         {@link GSSException#BAD_MECH GSSException.BAD_MECH},
     *         {@link GSSException#FAILURE GSSException.FAILURE}
     */
    public int getRemainingInitLifetime(Oid mech) throws GSSException;

    
Returns the lifetime in seconds for the credential to remain capable
of accepting security contexts using the specified mechanism. This
method queries the acceptor credential element that belongs to the
specified mechanism.

Params:
  • mech – the Oid of the mechanism whose acceptor credential element
should be queried.
Throws:
Returns:the number of seconds remaining in the life of this credential element. A return value of 
INDEFINITE_LIFETIME indicates that the credential element does not expire. A return value of 0 indicates that the credential element is already expired.
/**
     * Returns the lifetime in seconds for the credential to remain capable
     * of accepting security contexts using the specified mechanism. This
     * method queries the acceptor credential element that belongs to the
     * specified mechanism.
     *
     * @return the number of seconds remaining in the life of this credential
     * element. A return value of {@link #INDEFINITE_LIFETIME
     * INDEFINITE_LIFETIME} indicates that the credential element does not
     * expire.  A return value of 0 indicates that the credential element is
     * already expired.
     *
     * @param mech the Oid of the mechanism whose acceptor credential element
     * should be queried.
     *
     * @throws GSSException containing the following
     * major error codes:
     *         {@link GSSException#BAD_MECH GSSException.BAD_MECH},
     *         {@link GSSException#FAILURE GSSException.FAILURE}
     */
    public int getRemainingAcceptLifetime(Oid mech) throws GSSException;

    
Returns the credential usage mode. In other words, it
tells us if this credential can be used for initiating or accepting
security contexts. It does not tell us which mechanism(s) has to be
used in order to do so. It is expected that an application will allow
the GSS-API to pick a default mechanism after calling this method.

Throws:
Returns:The return value will be one of 
INITIATE_ONLY, ACCEPT_ONLY, and INITIATE_AND_ACCEPT.
/**
     * Returns the credential usage mode. In other words, it
     * tells us if this credential can be used for initiating or accepting
     * security contexts. It does not tell us which mechanism(s) has to be
     * used in order to do so. It is expected that an application will allow
     * the GSS-API to pick a default mechanism after calling this method.
     *
     * @return The return value will be one of {@link #INITIATE_ONLY
     * INITIATE_ONLY}, {@link #ACCEPT_ONLY ACCEPT_ONLY}, and {@link
     * #INITIATE_AND_ACCEPT INITIATE_AND_ACCEPT}.
     *
     * @throws GSSException containing the following
     * major error codes:
     *         {@link GSSException#FAILURE GSSException.FAILURE}
     */
    public int getUsage() throws GSSException;

    
Returns the credential usage mode for a specific mechanism. In other
words, it tells us if this credential can be used
for initiating or accepting security contexts with a given underlying
mechanism.

Params:
  • mech – the Oid of the mechanism whose credentials usage mode is
to be determined.
Throws:
Returns:The return value will be one of 
INITIATE_ONLY, ACCEPT_ONLY, and INITIATE_AND_ACCEPT.
/**
     * Returns the credential usage mode for a specific mechanism. In other
     * words, it tells us if this credential can be used
     * for initiating or accepting security contexts with a given underlying
     * mechanism.
     *
     * @return The return value will be one of {@link #INITIATE_ONLY
     * INITIATE_ONLY}, {@link #ACCEPT_ONLY ACCEPT_ONLY}, and {@link
     * #INITIATE_AND_ACCEPT INITIATE_AND_ACCEPT}.
     * @param mech the Oid of the mechanism whose credentials usage mode is
     * to be determined.
     *
     * @throws GSSException containing the following
     * major error codes:
     *         {@link GSSException#BAD_MECH GSSException.BAD_MECH},
     *         {@link GSSException#FAILURE GSSException.FAILURE}
     */
    public int getUsage(Oid mech) throws GSSException;

    
Returns a list of mechanisms supported by this credential. It does not tell us which ones can be used to initiate contexts and which ones can be used to accept contexts. The application must call the getUsage method with each of the returned Oid's to determine the possible modes of usage. 
Throws:
Returns:an array of Oid's corresponding to the supported mechanisms.
/**
     * Returns a list of mechanisms supported by this credential. It does
     * not tell us which ones can be used to initiate
     * contexts and which ones can be used to accept contexts. The
     * application must call the {@link #getUsage(Oid) getUsage} method with
     * each of the returned Oid's to determine the possible modes of
     * usage.
     *
     * @return an array of Oid's corresponding to the supported mechanisms.
     *
     * @throws GSSException containing the following
     * major error codes:
     *         {@link GSSException#FAILURE GSSException.FAILURE}
     */
    public Oid[] getMechs() throws GSSException;

    
Adds a mechanism specific credential-element to an existing
credential.  This method allows the construction of credentials, one
mechanism at a time.

This routine is envisioned to be used mainly by context acceptors
during the creation of acceptor credentials which are to be used
with a variety of clients using different security mechanisms.

This routine adds the new credential element "in-place".  To add the
element in a new credential, first call clone to obtain a
copy of this credential, then call its add method.
 As always, GSS-API implementations must impose a local access-control policy on callers to prevent unauthorized callers from acquiring credentials to which they are not entitled. Non-default values for initLifetime and acceptLifetime cannot always be honored by the underlying mechanisms, thus callers should be prepared to call 
getRemainingInitLifetime and 
getRemainingAcceptLifetime on the credential. 
Params:
  • name – the name of the principal for whom this credential is to
be acquired.  Use null to specify the default
principal.
  • initLifetime – the number of seconds that the credential element should remain valid for initiating of security contexts. Use GSSCredential.INDEFINITE_LIFETIME to request that the credentials have the maximum permitted lifetime for this. Use 
GSSCredential.DEFAULT_LIFETIME to request default credential lifetime for this.
  • acceptLifetime – the number of seconds that the credential element should remain valid for accepting security contexts. Use GSSCredential.INDEFINITE_LIFETIME to request that the credentials have the maximum permitted lifetime for this. Use 
GSSCredential.DEFAULT_LIFETIME to request default credential lifetime for this.
  • mech – the mechanism over which the credential is to be acquired.
  • usage – the usage mode that this credential element should add to the credential. The value of this parameter must be one of: INITIATE_AND_ACCEPT, ACCEPT_ONLY, and INITIATE_ONLY.
Throws:
/**
     * Adds a mechanism specific credential-element to an existing
     * credential.  This method allows the construction of credentials, one
     * mechanism at a time.<p>
     *
     * This routine is envisioned to be used mainly by context acceptors
     * during the creation of acceptor credentials which are to be used
     * with a variety of clients using different security mechanisms.<p>
     *
     * This routine adds the new credential element "in-place".  To add the
     * element in a new credential, first call <code>clone</code> to obtain a
     * copy of this credential, then call its <code>add</code> method.<p>
     *
     * As always, GSS-API implementations must impose a local access-control
     * policy on callers to prevent unauthorized callers from acquiring
     * credentials to which they are not entitled.
     *
     * Non-default values for initLifetime and acceptLifetime cannot always
     * be honored by the underlying mechanisms, thus callers should be
     * prepared to call {@link #getRemainingInitLifetime(Oid)
     * getRemainingInitLifetime} and {@link #getRemainingAcceptLifetime(Oid)
     * getRemainingAcceptLifetime} on the credential.
     *
     * @param name the name of the principal for whom this credential is to
     * be acquired.  Use <code>null</code> to specify the default
     * principal.
     * @param initLifetime the number of seconds that the credential element
     * should remain valid for initiating of security contexts. Use {@link
     * GSSCredential#INDEFINITE_LIFETIME GSSCredential.INDEFINITE_LIFETIME}
     * to request that the credentials have the maximum permitted lifetime
     * for this.  Use {@link GSSCredential#DEFAULT_LIFETIME
     * GSSCredential.DEFAULT_LIFETIME} to request default credential lifetime
     * for this.
     * @param acceptLifetime the number of seconds that the credential
     * element should remain valid for accepting security contexts. Use {@link
     * GSSCredential#INDEFINITE_LIFETIME GSSCredential.INDEFINITE_LIFETIME}
     * to request that the credentials have the maximum permitted lifetime
     * for this.  Use {@link GSSCredential#DEFAULT_LIFETIME
     * GSSCredential.DEFAULT_LIFETIME} to request default credential lifetime
     * for this.
     * @param mech the mechanism over which the credential is to be acquired.
     * @param usage the usage mode that this credential
     * element should add to the credential. The value
     * of this parameter must be one of:
     * {@link #INITIATE_AND_ACCEPT INITIATE_AND_ACCEPT},
     * {@link #ACCEPT_ONLY ACCEPT_ONLY}, and
     * {@link #INITIATE_ONLY INITIATE_ONLY}.
     *
     * @throws GSSException containing the following
     * major error codes:
     *         {@link GSSException#DUPLICATE_ELEMENT
     *                          GSSException.DUPLICATE_ELEMENT},
     *         {@link GSSException#BAD_MECH GSSException.BAD_MECH},
     *         {@link GSSException#BAD_NAMETYPE GSSException.BAD_NAMETYPE},
     *         {@link GSSException#NO_CRED GSSException.NO_CRED},
     *         {@link GSSException#CREDENTIALS_EXPIRED
     *                                  GSSException.CREDENTIALS_EXPIRED},
     *         {@link GSSException#FAILURE GSSException.FAILURE}
     */
    public void add(GSSName name, int initLifetime, int acceptLifetime,
                    Oid mech, int usage) throws GSSException;

    
Tests if this GSSCredential asserts the same entity as the supplied
object.  The two credentials must be acquired over the same
mechanisms and must refer to the same principal.

Params:
  • another – another GSSCredential for comparison to this one
Returns:true if the two GSSCredentials assert the same
entity; false otherwise.
/**
     * Tests if this GSSCredential asserts the same entity as the supplied
     * object.  The two credentials must be acquired over the same
     * mechanisms and must refer to the same principal.
     *
     * @return <code>true</code> if the two GSSCredentials assert the same
     * entity; <code>false</code> otherwise.
     * @param another another GSSCredential for comparison to this one
     */
    public boolean equals(Object another);

    
Returns a hashcode value for this GSSCredential.

Returns:a hashCode value
/**
     * Returns a hashcode value for this GSSCredential.
     *
     * @return a hashCode value
     */
    public int hashCode();

}