/*
* @(#)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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* 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.List;
import java.util.Set;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import com.sun.xacml.combine.CombinerElement;
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
*
* Adding generic type support by Christian Mueller (geotools)
*/
public class Policy extends AbstractPolicy {
// the set of variable definitions in this policy
private Set<VariableDefinition> 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<Rule> 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<Rule> 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<Rule> 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<Rule> rules, Set<Obligation> 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<Rule> rules, Set<Obligation> obligations,
Set<VariableDefinition> definitions) {
super(id, version, combiningAlg, description, target, defaultVersion, obligations, null);
List<CombinerElement> list = null;
// check that the list contains only rules
if (rules != null) {
list = new ArrayList<CombinerElement>();
for (Rule rule : rules) {
list.add(new RuleCombinerElement(rule));
}
}
setChildren(list);
// save the definitions
if (definitions == null)
this.definitions = Collections.emptySet();
else
this.definitions = Collections.unmodifiableSet(new HashSet<VariableDefinition>(
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<RuleCombinerElement> ruleElements,
Set<Obligation> obligations, Set<VariableDefinition> definitions,
List<CombinerParameter> parameters) {
super(id, version, combiningAlg, description, target, defaultVersion, obligations,
parameters);
setChildren(ruleElements);
// save the definitions
if (definitions == null)
this.definitions = Collections.emptySet();
else
this.definitions = Collections.unmodifiableSet(new HashSet<VariableDefinition>(
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<Rule> rules = new ArrayList<Rule>();
HashMap<String, List<CombinerParameter>> parameters = new HashMap<String, List<CombinerParameter>>();
HashMap<String, Node> variableIds = new HashMap<String, Node>();
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<VariableDefinition>();
// 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<CombinerParameter> list = parameters.get(ref);
parseParameters(list, child);
} else {
List<CombinerParameter> list = new ArrayList<CombinerParameter>();
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<CombinerElement> elements = new ArrayList<CombinerElement>();
for (Rule rule : rules) {
String id = rule.getId().toString();
List<CombinerParameter> 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<CombinerParameter> 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<VariableDefinition> 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);
for (VariableDefinition def : definitions)
def.encode(output, indenter);
encodeCommonElements(output, indenter);
indenter.out();
out.println(indent + "</Policy>");
}
}