sipdialogpermission.java

First of all, the Applet-phone is a SIP User-Agent with audio and text messaging capabilities. But

/*
 * SipDialogPermission.java
 *
 * Created on September 25, 2003, 12:11 PM
 */

package gov.nist.security.permissions;

import java.util.*;
/**
 * Permission specific to the SIP protocol
 * hecking if we overstepped the maximum number of dialog 
 * @author  DERUELLE Jean
 */
public class SipDialogPermission extends java.security.Permission {
    /**maximum number of dialog allowed*/
    int forkingFactor=0;
    /**mask of the actions*/
    protected int mask;
    static private int CREATE=0x01;
    
    /** Creates a new instance of SipDialogPermission 
     * @param name - name of the permission    
     */
    public SipDialogPermission(String name) {
        this(name,"create");        
        try{
            forkingFactor=Integer.parseInt(name);
        }
        catch(NumberFormatException nfe){
            nfe.printStackTrace();
        }        
    }
    
    /** Creates a new instance of SipDialogPermission
     * @param name - name of the permission     
     * @param actions - the actions of the permission
     */
    public SipDialogPermission(String name,String actions) {
        super(name);
        try{
            forkingFactor=Integer.parseInt(name);
        }
        catch(NumberFormatException nfe){
            nfe.printStackTrace();
        }
        parse(actions);
    }
    
    /**
     * Look into the actions String to get the actions
     * associated with that permission
     * @param actions - the actions String
     */
    private void parse(String actions){
        //Look into the action string for
        //the words incoming or outgoing or both
        StringTokenizer st=new StringTokenizer(actions,",\t");
        mask=0;
        while(st.hasMoreTokens()){
            String tok=st.nextToken();
            if(tok.equals("create"))
                    mask|=CREATE;
                 else throw new IllegalArgumentException("Unknown action "+ tok);
        }
                
    }
    /**
     * This method return the actions' String
     * @return the actions of the permission
     */
    public String getActions() {
        //This method must return the same String, no matter how
        //the action list was passed to the constructor.
        if(mask==0)
            return "";
        else if(mask==CREATE)
            return "create";
        else throw new IllegalArgumentException("Unknown mask");
    }
    
    /**
     * Checks if the specified permission's actions are "implied by" this object's actions.
     * @param permission - the permission to check against.
     * @return if the specified permission is implied by this object, false if not. 
     */
    public boolean implies(java.security.Permission permission) {
        if(!(permission instanceof SipDialogPermission))
            return false;
        SipDialogPermission sipDialogPermission=(SipDialogPermission)permission;
        //Similarly, the requested actions must macth all match actions
        //that we've been constructed with
        if((mask & sipDialogPermission.mask) !=sipDialogPermission.mask)
            return false;
        
        int permissionForkingFactor=0;
        try{
            permissionForkingFactor=Integer.parseInt(sipDialogPermission.getName());
        }        
        catch(NumberFormatException nfe){
            nfe.printStackTrace();
            return false;
        }
        //System.out.println("seuil : "+forkingFactor);
        //System.out.println("user : "+permissionForkingFactor);
        if(permissionForkingFactor<=forkingFactor)
            return true;
        return false;
    }
    
    /**
     * @see java.security.Permission#hashCode()
     */
    public int hashCode(){
        //We must always provide the same hashcode for permissions
        //because the hashes must match if the permissions compare
        // as equals
        return getName().hashCode() ^ mask; 
    }
    
    /**
     * @see java.security.Permission#equals(Object obj)
     */
    public boolean equals(Object o){
        if(!(o instanceof SipDialogPermission))
            return false;
        SipDialogPermission sipDialogPermission=(SipDialogPermission)o;
        //For equality, we check the name and the action mask
        return ((sipDialogPermission.getName().equals(getName())) && (sipDialogPermission.mask == mask));
    }
}