authenticationcredential.java

jxta平台的开发包

/*
 * Copyright (c) 2001 Sun Microsystems, Inc.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution,
 *    if any, must include the following acknowledgment:
 *       "This product includes software developed by the
 *       Sun Microsystems, Inc. for Project JXTA."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
 *
 * 4. The names "Sun", "Sun Microsystems, Inc.", "JXTA" and "Project JXTA" must
 *    not be used to endorse or promote products derived from this
 *    software without prior written permission. For written
 *    permission, please contact Project JXTA at http://www.jxta.org.
 *
 * 5. Products derived from this software may not be called "JXTA",
 *    nor may "JXTA" appear in their name, without prior written
 *    permission of Sun.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL SUN MICROSYSTEMS OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of Project JXTA.  For more
 * information on Project JXTA, please see
 * <http://www.jxta.org/>.
 *
 * This license is based on the BSD license adopted by the Apache Foundation.
 *
 * $Id: AuthenticationCredential.java,v 1.20 2006/03/17 17:37:08 bondolo Exp $
 */
package net.jxta.credential;

import java.net.URI;
import java.util.Enumeration;

import java.net.URISyntaxException;

import org.apache.log4j.Logger;
import org.apache.log4j.Level;

import net.jxta.document.Attributable;
import net.jxta.document.Attribute;
import net.jxta.document.Element;
import net.jxta.document.MimeMediaType;
import net.jxta.document.StructuredDocument;
import net.jxta.document.StructuredDocumentFactory;
import net.jxta.document.StructuredDocumentUtils;
import net.jxta.document.TextElement;
import net.jxta.id.ID;
import net.jxta.id.IDFactory;
import net.jxta.peergroup.PeerGroup;
import net.jxta.service.Service;

/**
 * Authenication credentials are used by JXTA Membership Services as the
 * basis for applications for peergroup membership. The AuthenticationCredential
 * provides two important pieces of inforamtion:
 * <ul>
 *   <li>the authetication method being requested</li>
 *   <li>identity information which will be provided to that authentication
 *   method.</li>
 * <ul>
 *
 * <p/>Not all authentication methods use the identity nformation.
 *
 * @see net.jxta.credential.Credential
 * @see net.jxta.membership.MembershipService
 * @see net.jxta.membership.Authenticator
 **/
public final class AuthenticationCredential implements Credential {

    /**
     *  Log4J Logger
     **/
    private final static transient Logger LOG = Logger.getLogger(AuthenticationCredential.class.getName());
    
    /**
     * the authentication method which will be requested when this credential is
     * provided during "apply" to a peergroup membership service.
     **/
    private String authenticationMethod = null;
    
    /**
     * Any optional information which is required by the requested authentication
     * method.
     **/
    private Element identityInfo = null;
    
    /**
     * The peergroup of this AuthenticationCredential
     **/
    private final PeerGroup peergroup;
    
    /**
     * Creates new AuthenticationCredential
     *
     * @param peergroup The peergroup context in which this
     * AuthenticationCredential is created.
     * @param method The authentication method which will be requested when the
     * AuthentiationCredential is provided to the peergroup Membership Service.
     * Authentication methods are specific to Membership services. Consult the
     * Documentation for the Membership service you will be authenticating
     * against in order to determine the valid <tt>method</tt> values. Every
     * Membership service should support a default authentication method which
     * can be specified as <tt>null</null>. 
     * @param indentityInfo Optional additional information which is used by the 
     * authentication method or <tt>null</tt>. This information is passed to the 
     * authentication method during the apply operation of the Membership 
     * Service. Consult the documentation for the specific Membership Service
     * you are using for details on how this information is used (if at all).
     **/
    public AuthenticationCredential( PeerGroup peergroup, String method, Element indentityInfo ) {
        this.peergroup = peergroup;
        
        authenticationMethod = method;
        
        if( null != indentityInfo ) {
            this.identityInfo = StructuredDocumentUtils.copyAsDocument(indentityInfo);
        }
    }

    /**
     * Creates new AuthenticationCredential
     *
     * @param peergroup The peergroup context in which this
     * AuthenticationCredential is created.
     * @param root the document containing the serialized representation of the
     * AuthenticationCredential.
     **/
    public AuthenticationCredential( PeerGroup peergroup, Element root ) {
        
        this.peergroup = peergroup;
        
        initialize( root );
    }
    
    /**
     * {@inheritDoc}
     *
     * <p/>AuthenticationCredentials are created in the context of a PeerGroup
     * though they are generally independant of peergroups. The intent is that
     * the AuthenticationCredential will be passed to the MembershipService
     * service of the same peergroup as the AuthenticationCredenitals.
     *
     * @return PeerGroupID associated with this AuthenticationCredential.
     **/
    public ID getPeerGroupID() {
        return peergroup.getPeerGroupID();
    }

    /**
     * {@inheritDoc}
     **/
    public ID getPeerID() {
        return peergroup.getPeerID();
    }

    /**
     * {@inheritDoc}
     **/
    public Service getSourceService() {
        return null;
    }
    
    /**
     * {@inheritDoc}
     *
     * <p/>AuthenticationCredential are never expired. The Authenticator will
     * determine the true validity from the included identity info.
     **/
    public boolean isExpired() {
        return false;
        }
    
    /**
     * {@inheritDoc}
     *
     * <p/>AuthenticationCredential are always valid, the Authenticator will
     * determine the true validity from the included identity info.
     **/
    public boolean isValid() {
        return true;
    }
    
    /**
     * {@inheritDoc}
     *
     * <p/>There is no straightforward mechansim for identifying the subject
     * unfortunately.
     **/
    public Object getSubject() {
        return null;
    }
    
    /**
     * Write credential into a document. as is a mime media-type
     * specification and provides the form of the document which is being
     * requested. Two standard document forms are defined. "text/text" encodes
     * the document in a form nice for printing out and "text/xml" which
     * provides an XML format.
     *
     * @param as The mime media type of the encoding format being requested.
     * @throws Exception When errors occur.
     * @return the StructuredDocument which represents this credential.
     **/
    public StructuredDocument getDocument(MimeMediaType as) throws Exception {
            
        StructuredDocument doc = StructuredDocumentFactory.newStructuredDocument( as, "jxta:Cred" );
        
        if( doc instanceof Attributable ) {
            ((Attributable)doc).addAttribute( "xmlns:jxta", "http://jxta.org" );
            ((Attributable)doc).addAttribute( "xml:space", "preserve" );
            ((Attributable)doc).addAttribute( "type", "AuthenticationCredential" );
        }
        
        Element e = doc.createElement( "Method", getMethod() );
        doc.appendChild( e );

        e = doc.createElement( "PeerGroupID", getPeerGroupID().toString() );
        doc.appendChild( e );
        
        e = doc.createElement( "PeerID", getPeerID().toString() );
        doc.appendChild( e );

        if( null != identityInfo ) {
            e = doc.createElement( "IdentityInfo");
            doc.appendChild( e );
        
            StructuredDocumentUtils.copyElements( doc, e, identityInfo );
            }

        return doc;
    }

    /**
     * Returns the authentication method which this AuthenticationCredential
     * will be requesting when it is provided to a Membership Service during the
     * "Apply" operation.
     *
     * @return String containing the authentication method being requested.
     **/
    public String getMethod() {
        return authenticationMethod;
    }
    
    protected void setMethod( String authenticationMethod ) {
        this.authenticationMethod = authenticationMethod;
    }
    
    /**
     * Returns the StructuredDocument Element containing the identity information which was
     * originally provided when this AuthenticationCredential was created.
     *
     * @return StructuredDocument Element containing the identity information which was
     * originally provided when this AuthenticationCredential was created.
     **/
    public Element getIdentityInfo() {
        return (null == identityInfo) ? null : StructuredDocumentUtils.copyAsDocument(identityInfo);
    }
    /**
     *  Process an individual element from the document.
     *
     *  @param elem the element to be processed.
     *  @return true if the element was recognized, otherwise false.
     **/
    protected boolean handleElement( TextElement elem ) {
        if( elem.getName().equals("PeerGroupID")) {
            try {
                URI gID = new URI( elem.getTextValue() );
                ID pgid = IDFactory.fromURI( gID );
                if( !pgid.equals( getPeerGroupID() ) ) {
                    throw new IllegalArgumentException( "Operation is from a different group. " + pgid + " != " + getPeerGroupID() );
                }
            } catch ( URISyntaxException badID ) {
                throw new IllegalArgumentException( "Unusable ID in advertisement: " + elem.getTextValue() );
            }
            return true;
        }
        
        if( elem.getName().equals("PeerID")) {
            try {
                URI pID = new URI( elem.getTextValue() );
                ID pid = IDFactory.fromURI( pID );
                if( !pid.equals( getPeerID() ) ) {
                    throw new IllegalArgumentException( "Operation is from a different group. " + pid + " != " + getPeerID() );
                }
            } catch ( URISyntaxException badID ) {
                throw new IllegalArgumentException( "Bad Peer ID in advertisement: " + elem.getTextValue() );
            } catch ( ClassCastException badID ) {
                throw new IllegalArgumentException( "Id is not a peer id: " + elem.getTextValue() );
            }
            return true;
        }
        
        if( elem.getName().equals("Method")) {
            setMethod( elem.getTextValue() );
            return true;
        }
        
        if( elem.getName().equals("IdentityInfo")) {
            Enumeration firstChild = elem.getChildren( );
            if( !firstChild.hasMoreElements() ) {
                throw new IllegalArgumentException( "Missing identity info" );
            }
                
            identityInfo = StructuredDocumentUtils.copyAsDocument( (Element) firstChild.nextElement() );
            
            return true;
        }
        
        // element was not handled
        return false;
    }
    
    /**
     *  Intialize from a portion of a structured document.
     **/
    protected void initialize( Element root ) {
        
        if( !TextElement.class.isInstance( root ) ) {
            throw new IllegalArgumentException( getClass().getName() + " only supports TextElement" );
        }
        
        TextElement doc = (TextElement) root;
        
        String typedoctype = "";
        if( root instanceof Attributable ) {
            Attribute itsType = ((Attributable)root).getAttribute( "type" );
            if( null != itsType ) {
                typedoctype = itsType.getValue();
            }
        }
        
        String doctype = doc.getName();
        
        if( !"jxta:AuthenticationCredential".equals(doctype) && !"jxta:AuthenticationCredential".equals(typedoctype) ) {
            throw new IllegalArgumentException( "Could not construct : "
            + getClass().getName() + "from doc containing a " + doctype );
        }
        
        Enumeration elements = doc.getChildren();
        
        while (elements.hasMoreElements()) {
            TextElement elem = (TextElement) elements.nextElement();
            
            if( !handleElement( elem ) ) {
                if (LOG.isEnabledFor(Level.WARN)) {
                    LOG.warn("Unhandleded element '" + elem.getName() + "' in " + doc.getName() );
                }
            };
        }
        
        // sanity check time!
        
        // FIXME [e-mail] 20030409 check things
    }
}