/*
* @(#)Policy.java
*
* Copyright 2003-2005 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. Redistribution of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* 2. Redistribution in binary form must reproduce the above copyright
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* documentation and/or other materials provided with the distribution.
*
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* be used to endorse or promote products derived from this software without
* specific prior written permission.
*
* This software is provided "AS IS," without a warranty of any kind. ALL
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package com.sun.xacml;
import java.io.OutputStream;
import java.io.PrintStream;
import java.net.URI;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Set;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import com.sun.xacml.combine.CombinerParameter;
import com.sun.xacml.combine.RuleCombinerElement;
import com.sun.xacml.combine.RuleCombiningAlgorithm;
import com.sun.xacml.cond.VariableDefinition;
import com.sun.xacml.cond.VariableManager;
/**
* Represents one of the two top-level constructs in XACML, the PolicyType.
* This optionally contains rules, which in turn contain most of the logic of
* a policy.
*
* @since 1.0
* @author Seth Proctor
*/
public class Policy extends AbstractPolicy
{
// the set of variable definitions in this policy
private Set definitions;
/**
* Creates a new <code>Policy</code> with only the required elements.
*
* @param id the policy identifier
* @param combiningAlg the <code>CombiningAlgorithm</code> used on the
* rules in this set
* @param target the <code>Target</code> for this policy
*/
public Policy(URI id, RuleCombiningAlgorithm combiningAlg, Target target) {
this(id, null, combiningAlg, null, target, null, null, null);
}
/**
* Creates a new <code>Policy</code> with only the required elements
* plus rules.
*
* @param id the policy identifier
* @param combiningAlg the <code>CombiningAlgorithm</code> used on the
* rules in this set
* @param target the <code>Target</code> for this policy
* @param rules a list of <code>Rule</code> objects
*
* @throws IllegalArgumentException if the <code>List</code> of rules
* contains an object that is not a
* <code>Rule</code>
*/
public Policy(URI id, RuleCombiningAlgorithm combiningAlg, Target target,
List rules) {
this(id, null, combiningAlg, null, target, null, rules, null);
}
/**
* Creates a new <code>Policy</code> with the required elements plus
* a version, rules, and a String description. Note that the version
* is an XACML 2.0 feature.
*
* @param id the policy identifier
* @param version the policy version or null for the default (this must
* always be null for XACML 1.x policies)
* @param combiningAlg the <code>CombiningAlgorithm</code> used on the
* rules in this set
* @param description a <code>String</code> describing the policy
* @param target the <code>Target</code> for this policy
* @param rules a list of <code>Rule</code> objects
*
* @throws IllegalArgumentException if the <code>List</code> of rules
* contains an object that is not a
* <code>Rule</code>
*/
public Policy(URI id, String version, RuleCombiningAlgorithm combiningAlg,
String description, Target target, List rules) {
this(id, version, combiningAlg, description, target, null, rules,
null);
}
/**
* Creates a new <code>Policy</code> with the required elements plus
* a version, rules, a String description and policy defaults. Note that
* the version is an XACML 2.0 feature.
*
* @param id the policy identifier
* @param version the policy version or null for the default (this must
* always be null for XACML 1.x policies)
* @param combiningAlg the <code>CombiningAlgorithm</code> used on the
* rules in this set
* @param description a <code>String</code> describing the policy
* @param target the <code>Target</code> for this policy
* @param defaultVersion the XPath version to use
* @param rules a list of <code>Rule</code> objects
*
* @throws IllegalArgumentException if the <code>List</code> of rules
* contains an object that is not a
* <code>Rule</code>
*/
public Policy(URI id, String version, RuleCombiningAlgorithm combiningAlg,
String description, Target target, String defaultVersion,
List rules) {
this(id, version, combiningAlg, description, target, defaultVersion,
rules, null);
}
/**
* Creates a new <code>Policy</code> with the required elements plus
* a version, rules, a String description, policy defaults, and
* obligations. Note that the version is an XACML 2.0 feature.
*
* @param id the policy identifier
* @param version the policy version or null for the default (this must
* always be null for XACML 1.x policies)
* @param combiningAlg the <code>CombiningAlgorithm</code> used on the
* rules in this set
* @param description a <code>String</code> describing the policy
* @param target the <code>Target</code> for this policy
* @param defaultVersion the XPath version to use
* @param rules a list of <code>Rule</code> objects
* @param obligations a set of <code>Obligations</code> objects
*
* @throws IllegalArgumentException if the <code>List</code> of rules
* contains an object that is not a
* <code>Rule</code>
*/
public Policy(URI id, String version, RuleCombiningAlgorithm combiningAlg,
String description, Target target, String defaultVersion,
List rules, Set obligations) {
this(id, version, combiningAlg, description, target, defaultVersion,
rules, obligations, null);
}
/**
* Creates a new <code>Policy</code> with the required elements plus
* a version, rules, a String description, policy defaults, obligations,
* and variable definitions. Note that the version and definitions are
* XACML 2.0 features.
*
* @param id the policy identifier
* @param version the policy version or null for the default (this must
* always be null for XACML 1.x policies)
* @param combiningAlg the <code>CombiningAlgorithm</code> used on the
* rules in this set
* @param description a <code>String</code> describing the policy
* @param target the <code>Target</code> for this policy
* @param defaultVersion the XPath version to use
* @param rules a list of <code>Rule</code> objects
* @param obligations a set of <code>Obligations</code> objects
* @param definitions a set of <code>VariableDefinition</code> objects
* that must provide all definitions referenced by
* all <code>VariableReference</code>s in the policy
*
* @throws IllegalArgumentException if the <code>List</code> of rules
* contains an object that is not a
* <code>Rule</code>
*/
public Policy(URI id, String version, RuleCombiningAlgorithm combiningAlg,
String description, Target target, String defaultVersion,
List rules, Set obligations, Set definitions) {
super(id, version, combiningAlg, description, target, defaultVersion,
obligations, null);
List list = null;
// check that the list contains only rules
if (rules != null) {
list = new ArrayList();
Iterator it = rules.iterator();
while (it.hasNext()) {
Object o = it.next();
if (! (o instanceof Rule))
throw new IllegalArgumentException("non-Rule in rules");
list.add(new RuleCombinerElement((Rule)o));
}
}
setChildren(list);
// save the definitions
if (definitions == null)
this.definitions = Collections.EMPTY_SET;
else
this.definitions = Collections.
unmodifiableSet(new HashSet(definitions));
}
/**
* Creates a new <code>Policy</code> with the required and optional
* elements. If you need to provide combining algorithm parameters, you
* need to use this constructor. Note that unlike the other constructors
* in this class, the rules list is actually a list of
* <code>CombinerElement</code>s used to match a rule with any
* combiner parameters it may have.
*
* @param id the policy identifier
* @param version the policy version or null for the default (this must
* always be null for XACML 1.x policies)
* @param combiningAlg the <code>CombiningAlgorithm</code> used on the
* rules in this set
* @param description a <code>String</code> describing the policy or
* null if there is no description
* @param target the <code>Target</code> for this policy
* @param defaultVersion the XPath version to use or null if there is
* no default version
* @param ruleElements a list of <code>RuleCombinerElement</code> objects
* or null if there are no rules
* @param obligations a set of <code>Obligations</code> objects or null
* if there are no obligations
* @param definitions a set of <code>VariableDefinition</code> objects
* that must provide all definitions referenced by
* all <code>VariableReference</code>s in the policy
* @param parameters the <code>List</code> of
* <code>CombinerParameter</code>s provided for general
* use by the combining algorithm
*
* @throws IllegalArgumentException if the <code>List</code> of rules
* contains an object that is not a
* <code>RuleCombinerElement</code>
*/
public Policy(URI id, String version, RuleCombiningAlgorithm combiningAlg,
String description, Target target, String defaultVersion,
List ruleElements, Set obligations, Set definitions,
List parameters) {
super(id, version, combiningAlg, description, target, defaultVersion,
obligations, parameters);
// check that the list contains only RuleCombinerElements
if (ruleElements != null) {
Iterator it = ruleElements.iterator();
while (it.hasNext()) {
Object o = it.next();
if (! (o instanceof RuleCombinerElement))
throw new IllegalArgumentException("non-Rule in rules");
}
}
setChildren(ruleElements);
// save the definitions
if (definitions == null)
this.definitions = Collections.EMPTY_SET;
else
this.definitions = Collections.
unmodifiableSet(new HashSet(definitions));
}
/**
* Creates a new Policy based on the given root node. This is
* private since every class is supposed to use a getInstance() method
* to construct from a Node, but since we want some common code in the
* parent class, we need this functionality in a constructor.
*/
private Policy(Node root) throws ParsingException {
super(root, "Policy", "RuleCombiningAlgId");
List rules = new ArrayList();
HashMap parameters = new HashMap();
HashMap variableIds = new HashMap();
PolicyMetaData metaData = getMetaData();
// first off, go through and look for any definitions to get their
// identifiers up front, since before we parse any references we'll
// need to know what definitions we support
NodeList children = root.getChildNodes();
for (int i = 0; i < children.getLength(); i++) {
Node child = children.item(i);
if (child.getNodeName().equals("VariableDefinition")) {
String id = child.getAttributes().
getNamedItem("VariableId").getNodeValue();
// it's an error to have more than one definition with the
// same identifier
if (variableIds.containsKey(id))
throw new ParsingException("multiple definitions for " +
"variable " + id);
variableIds.put(id, child);
}
}
// now create a manager with the defined variable identifiers
VariableManager manager = new VariableManager(variableIds, metaData);
definitions = new HashSet();
// next, collect the Policy-specific elements
for (int i = 0; i < children.getLength(); i++) {
Node child = children.item(i);
String name = child.getNodeName();
if (name.equals("Rule")) {
rules.add(Rule.getInstance(child, metaData, manager));
} else if (name.equals("RuleCombinerParameters")) {
String ref = child.getAttributes().getNamedItem("RuleIdRef").
getNodeValue();
// if we found the parameter before than add it the end of
// the previous paramters, otherwise create a new entry
if (parameters.containsKey(ref)) {
List list = (List)(parameters.get(ref));
parseParameters(list, child);
} else {
List list = new ArrayList();
parseParameters(list, child);
parameters.put(ref, list);
}
} else if (name.equals("VariableDefinition")) {
String id = child.getAttributes().
getNamedItem("VariableId").getNodeValue();
// parsing definitions is a little strange, since they can
// contain references to definitions we haven't yet parsed
// or circular references, but we still want to verify the
// references and the types...so, for each definition, we
// ask the manager though getDefinition, which takes care
// of loading any forward references, handles loops, etc.
// It also handles caching definitions, so we don't end
// up parsing the same definitions multiple times
definitions.add(manager.getDefinition(id));
}
}
definitions = Collections.unmodifiableSet(definitions);
// now make sure that we can match up any parameters we may have
// found to a cooresponding Rule...
List elements = new ArrayList();
Iterator it = rules.iterator();
while (it.hasNext()) {
Rule rule = (Rule)(it.next());
String id = rule.getId().toString();
List list = (List)(parameters.remove(id));
elements.add(new RuleCombinerElement(rule, list));
}
// ...and that there aren't extra parameters
if (! parameters.isEmpty())
throw new ParsingException("Unmatched parameters in Rule");
// finally, set the list of Rules
setChildren(elements);
}
/**
* Helper method that parses out a collection of combiner parameters.
*/
private void parseParameters(List parameters, Node root)
throws ParsingException
{
NodeList nodes = root.getChildNodes();
for (int i = 0; i < nodes.getLength(); i++) {
Node node = nodes.item(i);
if (node.getNodeName().equals("CombinerParameter"))
parameters.add(CombinerParameter.getInstance(node));
}
}
/**
* Creates an instance of a <code>Policy</code> object based on a
* DOM node. The node must be the root of PolicyType XML object,
* otherwise an exception is thrown.
*
* @param root the DOM root of a PolicyType XML type
*
* @throws ParsingException if the PolicyType is invalid
*/
public static Policy getInstance(Node root) throws ParsingException {
// first off, check that it's the right kind of node
if (! root.getNodeName().equals("Policy")) {
throw new ParsingException("Cannot create Policy from root of " +
"type " + root.getNodeName());
}
return new Policy(root);
}
/**
* Returns the variable definitions in this Policy.
*
* @return a <code>Set</code> of <code>VariableDefinition</code>s
*/
public Set getVariableDefinitions() {
return definitions;
}
/**
* Encodes this <code>Policy</code> into its XML representation and writes
* this encoding to the given <code>OutputStream</code> with no
* indentation.
*
* @param output a stream into which the XML-encoded data is written
*/
public void encode(OutputStream output) {
encode(output, new Indenter(0));
}
/**
* Encodes this <code>Policy</code> into its XML representation and writes
* this encoding to the given <code>OutputStream</code> with
* indentation.
*
* @param output a stream into which the XML-encoded data is written
* @param indenter an object that creates indentation strings
*/
public void encode(OutputStream output, Indenter indenter) {
PrintStream out = new PrintStream(output);
String indent = indenter.makeString();
out.println(indent + "<Policy PolicyId=\"" + getId().toString() +
"\" RuleCombiningAlgId=\"" +
getCombiningAlg().getIdentifier().toString() +
"\">");
indenter.in();
String nextIndent = indenter.makeString();
String description = getDescription();
if (description != null)
out.println(nextIndent + "<Description>" + description +
"</Description>");
String version = getDefaultVersion();
if (version != null)
out.println("<PolicyDefaults><XPathVersion>" + version +
"</XPathVersion></PolicyDefaults>");
getTarget().encode(output, indenter);
Iterator it = definitions.iterator();
while (it.hasNext())
((VariableDefinition)(it.next())).encode(output, indenter);
encodeCommonElements(output, indenter);
indenter.out();
out.println(indent + "</Policy>");
}
public Element toOWLNode(Document doc) {
Element policy = doc.createElement("Policy");
policy.setAttribute("rdf:ID", getId().toASCIIString());
Element hasRuleCombiningAlgorithm = doc.createElement("hasRuleCombiningAlgorithm");
hasRuleCombiningAlgorithm.setAttribute("rdf:resource",getCombiningAlg().getIdentifier().toString());
policy.appendChild(hasRuleCombiningAlgorithm);
//TODO Descriptions are omitted at the moment
// String description = getDescription();
// if (description != null)
// out.println(nextIndent + "<Description>" + description +
// "</Description>");
//TODO Policy version is omitted at the moment
// String version = getDefaultVersion();
// if (version != null)
// out.println("<PolicyDefaults><XPathVersion>" + version +
// "</XPathVersion></PolicyDefaults>");
Element hasTarget = doc.createElement("hasTarget");
Element target = getTarget().toOWLNode(doc);
hasTarget.appendChild(target);
policy.appendChild(hasTarget);
Iterator it = definitions.iterator();
while (it.hasNext()) {
Element variableElement = ((VariableDefinition)(it.next())).toOWLNode(doc);
policy.appendChild(variableElement);
}
//TODO CommonElements mit ausgeben
// encodeCommonElements(output, indenter);
Iterator ruleIt = this.getChildren().iterator();
while (ruleIt.hasNext()) {
Element hasRule = doc.createElement("hasRule");
Rule regel = (Rule) ruleIt.next();
Element rule = regel.toOWLNode(doc);
hasRule.appendChild(rule);
policy.appendChild(hasRule);
}
if (obligations!=null) {
if (obligations.size() != 0) {
it = obligations.iterator();
while (it.hasNext()) {
Element obligation = doc.createElement("hasObligation");
obligation.setAttribute("rdf:resource", ((Obligation)(it.next())).getId().toASCIIString());
policy.appendChild(obligation);
}
}
}
return policy;
}
}