/*
* @(#)StaticPolicyFinderModule.java
*
* Copyright 2006 Sun Microsystems, Inc. All Rights Reserved.
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package org.jboss.security.xacml.sunxacml.support.finder;
import java.io.File;
import java.net.MalformedURLException;
import java.net.URI;
import java.net.URISyntaxException;
import java.net.URL;
import java.util.Iterator;
import java.util.List;
import java.util.logging.Level;
import java.util.logging.Logger;
import org.jboss.security.xacml.sunxacml.AbstractPolicy;
import org.jboss.security.xacml.sunxacml.EvaluationCtx;
import org.jboss.security.xacml.sunxacml.ParsingException;
import org.jboss.security.xacml.sunxacml.UnknownIdentifierException;
import org.jboss.security.xacml.sunxacml.combine.CombiningAlgFactory;
import org.jboss.security.xacml.sunxacml.combine.PolicyCombiningAlgorithm;
import org.jboss.security.xacml.sunxacml.finder.PolicyFinder;
import org.jboss.security.xacml.sunxacml.finder.PolicyFinderModule;
import org.jboss.security.xacml.sunxacml.finder.PolicyFinderResult;
/**
* This is a simple implementation of <code>PolicyFinderModule</code> that
* supports retrieval based on context, and is designed for use with a
* run-time configuration. Its constructor accepts a <code>List</code> of
* <code>String</code>s that represent URLs or files, and these are resolved
* to policies when the module is initialized. Beyond this, there is no
* modifying or re-loading the policies represented by this class. This
* class will optionally wrap multiple applicable policies into a dynamic
* PolicySet.
* <p>
* Note that this class is designed to complement
* <code>StaticRefPolicyFinderModule</code>. It would be easy to support both
* kinds of policy retrieval in a single class, but the functionality is
* instead split between two classes. The reason is that when you define a
* configuration for your PDP, it's easier to specify the two sets of policies
* by using two different finder modules. Typically, there aren't many
* policies that exist in both sets, so loading the sets separately isn't
* a problem. If this is a concern to you, simply create your own class and
* merge the two existing classes.
* <p>
* This module is provided as an example, but is still fully functional, and
* should be useful for many simple applications. This is provided in the
* <code>support</code> package rather than the core codebase because it
* implements non-standard behavior.
*
* @since 2.0
* @author Seth Proctor
*/
@SuppressWarnings({ "rawtypes"})
public class StaticPolicyFinderModule extends PolicyFinderModule
{
// the list of policy URLs passed to the constructor
private List policyList;
// the map of policies
private PolicyCollection policies;
// the optional schema file
private File schemaFile = null;
// the policy identifier for any policy sets we dynamically create
private static final String POLICY_ID = "urn:com:sun:xacml:support:finder:dynamic-policy-set";
private static URI policyId = null;
// the logger we'll use for all messages
private static final Logger logger = Logger.getLogger(StaticPolicyFinderModule.class.getName());
static
{
try
{
policyId = new URI(POLICY_ID);
}
catch (Exception e)
{
// this can't actually happen, but just in case...
if (logger.isLoggable(Level.SEVERE))
logger.log(Level.SEVERE, "couldn't assign default policy id");
}
};
/**
* Creates a <code>StaticPolicyFinderModule</code> that provides
* access to the given collection of policies and returns an error when
* more than one policy matches a given context. Any policy that cannot
* be loaded will be noted in the log, but will not cause an error. The
* schema file used to validate policies is defined by the property
* <code>PolicyReader.POLICY_SCHEMA_PROPERTY</code>. If the retrieved
* property is null, then no schema validation will occur.
*
* @param policyList a <code>List</code> of <code>String</code>s that
* represent URLs or files pointing to XACML policies
*/
public StaticPolicyFinderModule(List policyList)
{
this.policyList = policyList;
this.policies = new PolicyCollection();
String schemaName = System.getProperty(PolicyReader.POLICY_SCHEMA_PROPERTY);
if (schemaName != null)
schemaFile = new File(schemaName);
}
/**
* Creates a <code>StaticPolicyFinderModule</code> that provides
* access to the given collection of policies and returns an error when
* more than one policy matches a given context. Any policy that cannot
* be loaded will be noted in the log, but will not cause an error.
*
* @param policyList a <code>List</code> of <code>String</code>s that
* represent URLs or files pointing to XACML policies
* @param schemaFile the schema file to validate policies against,
* or null if schema validation is not desired
*/
public StaticPolicyFinderModule(List policyList, String schemaFile)
{
this.policyList = policyList;
this.policies = new PolicyCollection();
if (schemaFile != null)
this.schemaFile = new File(schemaFile);
}
/**
* Creates a <code>StaticPolicyFinderModule</code> that provides
* access to the given collection of policies. The given combining
* algorithm is used to create new PolicySets when more than one
* policy applies. Any policy that cannot be loaded will be noted in
* the log, but will not cause an error. The schema file used to
* validate policies is defined by the property
* <code>PolicyReader.POLICY_SCHEMA_PROPERTY</code>. If the retrieved
* property is null, then no schema validation will occur.
*
* @param combiningAlg the algorithm to use in a new PolicySet when more
* than one policy applies
* @param policyList a <code>List</code> of <code>String</code>s that
* represent URLs or files pointing to XACML policies
*
* @throws URISyntaxException if the combining algorithm is not a
* well-formed URI
* @throws UnknownIdentifierException if the combining algorithm identifier
* isn't known
*/
public StaticPolicyFinderModule(String combiningAlg, List policyList) throws URISyntaxException,
UnknownIdentifierException
{
PolicyCombiningAlgorithm alg = (PolicyCombiningAlgorithm) (CombiningAlgFactory.getInstance()
.createAlgorithm(new URI(combiningAlg)));
this.policyList = policyList;
this.policies = new PolicyCollection(alg, policyId);
String schemaName = System.getProperty(PolicyReader.POLICY_SCHEMA_PROPERTY);
if (schemaName != null)
schemaFile = new File(schemaName);
}
/**
* Creates a <code>StaticPolicyFinderModule</code> that provides
* access to the given collection of policies. The given combining
* algorithm is used to create new PolicySets when more than one
* policy applies. Any policy that cannot be loaded will be noted in
* the log, but will not cause an error.
*
* @param combiningAlg the algorithm to use in a new PolicySet when more
* than one policy applies
* @param policyList a <code>List</code> of <code>String</code>s that
* represent URLs or files pointing to XACML policies
* @param schemaFile the schema file to validate policies against,
* or null if schema validation is not desired
*
* @throws URISyntaxException if the combining algorithm is not a
* well-formed URI
* @throws UnknownIdentifierException if the combining algorithm identifier
* isn't known
*/
public StaticPolicyFinderModule(String combiningAlg, List policyList, String schemaFile) throws URISyntaxException,
UnknownIdentifierException
{
PolicyCombiningAlgorithm alg = (PolicyCombiningAlgorithm) (CombiningAlgFactory.getInstance()
.createAlgorithm(new URI(combiningAlg)));
this.policyList = policyList;
this.policies = new PolicyCollection(alg, policyId);
if (schemaFile != null)
this.schemaFile = new File(schemaFile);
}
/**
* Always returns <code>true</code> since this module does support
* finding policies based on context.
*
* @return true
*/
public boolean isRequestSupported()
{
return true;
}
/**
* Initialize this module. Typically this is called by
* <code>PolicyFinder</code> when a PDP is created. This method is
* where the policies are actually loaded.
*
* @param finder the <code>PolicyFinder</code> using this module
*/
public void init(PolicyFinder finder)
{
// now that we have the PolicyFinder, we can load the policies
PolicyReader reader = new PolicyReader(finder, logger, schemaFile);
Iterator it = policyList.iterator();
while (it.hasNext())
{
String str = (String) (it.next());
AbstractPolicy policy = null;
try
{
try
{
// first try to load it as a URL
URL url = new URL(str);
policy = reader.readPolicy(url);
}
catch (MalformedURLException murle)
{
// assume that this is a filename, and try again
policy = reader.readPolicy(new File(str));
}
// we loaded the policy, so try putting it in the collection
if (!policies.addPolicy(policy))
if (logger.isLoggable(Level.WARNING))
logger.log(Level.WARNING, "tried to load the same " + "policy multiple times: " + str);
}
catch (ParsingException pe)
{
if (logger.isLoggable(Level.WARNING))
logger.log(Level.WARNING, "Error reading policy: " + str, pe);
}
}
}
/**
* Finds a policy based on a request's context. If more than one policy
* matches, then this either returns an error or a new policy wrapping
* the multiple policies (depending on which constructor was used to
* construct this instance).
*
* @param context the representation of the request data
*
* @return the result of trying to find an applicable policy
*/
public PolicyFinderResult findPolicy(EvaluationCtx context)
{
try
{
AbstractPolicy policy = policies.getPolicy(context);
if (policy == null)
return new PolicyFinderResult();
else
return new PolicyFinderResult(policy);
}
catch (TopLevelPolicyException tlpe)
{
return new PolicyFinderResult(tlpe.getStatus());
}
}
}