attributeauthorityinformationaccess.java

一个完整的XACML工程,学习XACML技术的好例子!

/*
* Copyright (c) 2006, University of Kent
* All rights reserved.
*
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* modification, are permitted provided that the following conditions are met:
*
* Redistributions of source code must retain the above copyright notice, this 
* list of conditions and the following disclaimer.
* 
* 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. 
*
* 1. Neither the name of the University of Kent nor the names of its 
* contributors may be used to endorse or promote products derived from this 
* software without specific prior written permission. 
*
* 2. THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS  
* IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 
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* 3. IN NO EVENT SHALL THE COPYRIGHT OWNER OR 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 
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*
* 4. YOU AGREE THAT THE EXCLUSIONS IN PARAGRAPHS 2 AND 3 ABOVE ARE REASONABLE
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* IT IS INEVITABLE THAT THERE WILL BE BUGS AND ERRORS, AND POSSIBLY MORE
* SERIOUS FAULTS, IN THIS SOFTWARE.
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* 5. This license is governed, except to the extent that local laws
* necessarily apply, by the laws of England and Wales.
*/

/*
 * AttributeAuthorityInformationAccess.java
 *
 * Created on July 11, 2005, 4:29 PM
 */

package issrg.ac.attributes;

import iaik.asn1.*;
import iaik.asn1.structures.*;

import java.util.Enumeration;
import java.util.Vector;

/**
 *
 * @author anhnt
 */
public class AttributeAuthorityInformationAccess extends issrg.ac.Extension {
    
    /**
     *The string stores the OID for the Attribute authority information access: 1.2.826.0.1.3344810.10.0
     */
    public static final String ATTRIBUTE_AUTHORITY_INFORMATION_ACCESS = "1.2.826.0.1.3344810.10.0";
    
    /**
     *This string stores the standard OID for id_ad_caIssuer: 1.3.6.1.5.5.7.48.2
     */
    private static final String id_ad_caIssuer = "1.3.6.1.5.5.7.48.2";
    
    /**
     *This string stores the standard OID for id_ad_oscp: 1.3.6.1.5.5.7.48.1
     */
    
    private static final String id_ad_oscp = "1.3.6.1.5.5.7.48.1";
    
    private static final ObjectID ID_AD_CAISSUER_OID = new ObjectID(issrg.ac.attributes.AttributeAuthorityInformationAccess.id_ad_caIssuer);

    private String [] locations;
    
    /**
   * This method registers this extension as an extension with a specific
   * OID. After it has been registered, Extensions can recognise 
   * the extension with this OID.
   */  
    
    public static void registerMe() {
        issrg.ac.Extensions.registerExtension(ATTRIBUTE_AUTHORITY_INFORMATION_ACCESS, AttributeAuthorityInformationAccess.class);
    }
    
 
    /** Creates a new instance of AttributeAuthorityInformationAccess based on an 
     *existing AAIA extension
     *
     *@param e is an AAIA extension
     */
    
    public AttributeAuthorityInformationAccess(AttributeAuthorityInformationAccess e) throws CodingException {
      super(ATTRIBUTE_AUTHORITY_INFORMATION_ACCESS, false, e.getExtensionValue());
    }
    
    /**
     *This method constructs an AAIA extension based on an extension value
     *@param extnValue is an array of strings. It indicates the locations of 
     *the ACs of the AC's issuer
     */
    
    public AttributeAuthorityInformationAccess(String [] extnValue) {
        super(ATTRIBUTE_AUTHORITY_INFORMATION_ACCESS, false);
        setLocations(extnValue);
    }
    
    /**
     * This method constructs an AAIA extension based on an ASN1Object object
     *@param ao is the ASN1Object object that is used to construct the AAIA object.
     */
    
    public AttributeAuthorityInformationAccess(ASN1Object ao) throws CodingException {
        super(ao);
    }
    
    public Object clone() {
        try {
            return new AttributeAuthorityInformationAccess(this);
        } catch (CodingException ce) {return null;}
    }
    
    /**
   * This method decodes a given ASN1Object and upon successful decoding sets
   * the AAIA extension for the AC.
   *
   * @param ao - ASN1Object to decode
   */
    
    public void decode(ASN1Object ao) throws CodingException {
      super.decode(ao);
      if (isCritical()) throw new CodingException("AttributeAuthorityInformationAccess extension MUST be non-ctirical");
    }
    
    /**
     * This method decodes an ASN1Object to get the extension value of an AAIA 
     *extension.
     *
     *@param ao is an ASN1Object that is going to be decoded.
     */
    
    public void decodeValue(ASN1Object ao) throws CodingException {
        Vector location = new Vector();
        // we may want to check that ao is a SEQUENCE first
        int j = ao.countComponents();
        for (int i=0; i<j; i++) {
          ASN1Object accessDescription = ao.getComponentAt(i);
          try{
            if (!(accessDescription instanceof SEQUENCE)) throw new CodingException("Wrong extension value format: SEQUENCE expected");

            ASN1Object oid = (ASN1Object) accessDescription.getComponentAt(0);
            if (!(oid instanceof ObjectID)) throw new CodingException("Wrong extension value format: OBJECT IDENTIFIER expected");

            String id = (String) ((ObjectID) oid).getValue();
            if (!id.equals(id_ad_caIssuer)) { //only id-ad-caIssuers objectIdentifier is supported by now
              throw new CodingException("Unsupported OID found in AAIA extension: "+id);
            }

            ASN1Object generalName = (ASN1Object) accessDescription.getComponentAt(1);
            if (!(generalName instanceof CON_SPEC)) {
                throw new CodingException("GeneralName was expected as the extension value");
            }
            GeneralName gn = new GeneralName(generalName);
            if (gn.getType()!=GeneralName.uniformResourceIdentifier){
              continue; // skip the General Names that are not URLs
            }
            location.add(gn.getName().toString());   
          }catch(CodingException ce){
            // the extension is not critical - ignore the errors
          }
        }
        setLocations((String [])location.toArray(new String[0]));
    }

    
    public String[] getLocations() {
      return locations;
    }

    /**
     * This method sets the locations to an array of Strings, each representing the individual URL
     *
     *@param s is an array of strings that represent the ACs' locations.
     */
    
    public void setLocations(String [] s){
      locations=s;
    }
    
    /**
     *This method encodes the ACs' locations to an ASN1Object object.
     *@return an ASN1Object that represents the ACs's locations
     */
    public ASN1Object encodeValue() throws CodingException{
      String [] urls=getLocations();
      SEQUENCE extnV = new SEQUENCE();

      if (urls!=null){
        for (int i=0; i<urls.length; i++){
          GeneralName name = new GeneralName(GeneralName.uniformResourceIdentifier, urls[i]);

          SEQUENCE accessDesc = new SEQUENCE();
          accessDesc.addComponent(ID_AD_CAISSUER_OID, 0);
          accessDesc.addComponent(name.toASN1Object(), 1);
          extnV.addComponent(accessDesc);
        }
      }

      return extnV;
    }
    
    /**
     *This method creates a string that represents all the issuer AC locations
     *@param ident is a string used to separate the locations
     *@return a string that represents all the issuer AC locations
     */

    public String extensionValueToString(String ident){
      String[] b = getLocations();
      
      String a= "";
      
      if (b!=null){
        for (int i = 0; i < b.length; i++) {
            if (i>0) a = a.concat("  ");
            a = a.concat((String)b[i]);
        }
      }else{
        a="(no locations set)";
      }
      return a;
    }
}