package org.fcrepo.server.security.xacml.pdp.finder.attribute;
import java.net.URI;
import java.net.URISyntaxException;
import java.util.HashSet;
import java.util.Set;
import org.fcrepo.common.rdf.SimpleURIReference;
import org.fcrepo.server.resourceIndex.ResourceIndex;
import org.fcrepo.server.security.PolicyFinderModule;
import org.fcrepo.server.security.xacml.pdp.finder.AttributeFinderException;
import org.jrdf.graph.PredicateNode;
import org.jrdf.graph.SubjectNode;
import org.jrdf.graph.Triple;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.trippi.TripleIterator;
import org.trippi.TrippiException;
import com.sun.xacml.EvaluationCtx;
import com.sun.xacml.attr.AttributeFactory;
import com.sun.xacml.attr.AttributeValue;
import com.sun.xacml.attr.BagAttribute;
import com.sun.xacml.attr.StandardAttributeFactory;
import com.sun.xacml.cond.EvaluationResult;
public class RITriplesAttributeFinder
extends DesignatorAttributeFinderModule {
private static final Logger logger =
LoggerFactory.getLogger(RITriplesAttributeFinder.class);
private final AttributeFactory m_attributeFactory = StandardAttributeFactory.getFactory();
private final ResourceIndex m_resourceIndex;
public RITriplesAttributeFinder(ResourceIndex resourceIndex) {
m_resourceIndex = resourceIndex;
}
public void init() throws AttributeFinderException {
if (emptyAttributeMap()) {
logger.warn(this.getClass().getName() + " configured with no registered attributes");
return;
}
if (logger.isDebugEnabled()) {
logger.debug("registering the following attributes: ");
for (int desNum : m_attributes.keySet()) {
for (String attrName : m_attributes.get(desNum).keySet()) {
logger.debug(desNum + ": " + attrName);
}
}
}
logger.info("Initialised AttributeFinder:"
+ this.getClass().getName());
}
/**
* Returns true always because this module supports designators.
*
* @return true always
*/
@Override
public boolean isDesignatorSupported() {
return true;
}
@Override
public Set<Integer> getSupportedDesignatorTypes() {
return m_attributes.keySet();
}
/**
* Used to get an attribute. If one of those values isn't being asked for,
* or if the types are wrong, then an empty bag is returned.
*
* @param attributeType
* the datatype of the attributes to find, which must be time, date,
* or dateTime for this module to resolve a value
* @param attributeId
* the identifier of the attributes to find, which must be one of the
* three ENVIRONMENT_* fields for this module to resolve a value
* @param issuer
* the issuer of the attributes, or null if unspecified
* @param subjectCategory
* the category of the attribute or null, which ignored since this
* only handles non-subjects
* @param context
* the representation of the request data
* @param designatorType
* the type of designator, which must be ENVIRONMENT_TARGET for this
* module to resolve a value
* @return the result of attribute retrieval, which will be a bag with a
* single attribute, an empty bag, or an error
*/
@Override
public EvaluationResult findAttribute(URI attributeType,
URI attributeId,
URI issuer,
URI subjectCategory,
EvaluationCtx context,
int designatorType) {
String resourceId = context.getResourceId().encode();
if (resourceId == null || resourceId.equals("")) {
String pid = PolicyFinderModule.getPid(context);
if (pid != null) {
resourceId = "info:fedora/" + pid;
}
}
if (logger.isDebugEnabled()) {
logger.debug("RITriplesAttributeFinder: [" + attributeType.toString() + "] "
+ attributeId + ", rid=" + resourceId);
}
if (resourceId == null || resourceId.equals("")) {
return new EvaluationResult(BagAttribute
.createEmptyBag(attributeType));
}
if (resourceId.equals("/FedoraRepository")) {
return new EvaluationResult(BagAttribute
.createEmptyBag(attributeType));
}
// figure out which attribute we're looking for
String attrName = attributeId.toString();
// we only know about registered attributes from Spring config
if (!m_attributes.containsKey(designatorType)) {
if (logger.isDebugEnabled()) {
logger.debug("Does not know about designatorType: "
+ designatorType);
}
return new EvaluationResult(BagAttribute
.createEmptyBag(attributeType));
}
Set<String> allowedAttributes =
m_attributes.get(designatorType).keySet();
if (!allowedAttributes.contains(attrName)) {
if (logger.isDebugEnabled()) {
logger.debug("Does not know about attribute: " + attrName);
}
return new EvaluationResult(BagAttribute
.createEmptyBag(attributeType));
}
EvaluationResult result = null;
try {
result = getEvaluationResult(resourceId, attrName, designatorType, attributeType);
} catch (Exception e) {
logger.error("Error finding attribute: " + e.getMessage(), e);
return new EvaluationResult(BagAttribute
.createEmptyBag(attributeType));
}
return result;
}
/**
*
* @param resourceID - the hierarchical XACML resource ID
* @param attribute - attribute to get - this is a URI that maps to a Fedora relationship name
* @param type
* @return
* @throws AttributeFinderException
*/
private EvaluationResult getEvaluationResult(String resourceID,
String attribute,
int designatorType,
URI type)
throws AttributeFinderException {
// split up the path of the hierarchical resource id
String resourceParts[] = resourceID.split("/");
Set<String> results = null;
// either the last part is the pid, or the last-but one is the pid and the last is the datastream
// if we have a pid, we query on that, if we have a datastream we query on the datastream
if (resourceParts.length <= 1) {
// eg /FedoraRepository, not a valid path to PID or PID/DS
logger.debug("Resource ID not valid path to PID or datastream: " + resourceID);
return new EvaluationResult(BagAttribute.createEmptyBag(type));
}
if (logger.isDebugEnabled()){
logger.debug("Getting attribute " + attribute +" for resource " + resourceID);
}
try{
SubjectNode snode = new SimpleURIReference(new URI(resourceID));
PredicateNode pnode = new SimpleURIReference(new URI(attribute));
TripleIterator triples = m_resourceIndex.findTriples(snode, pnode, null, 0);
results = new HashSet<String>();
while (triples.hasNext()){
Triple triple = triples.next();
String object = triple.getObject().stringValue();
results.add(object);
}
}
catch (TrippiException e){
logger.warn("Error retreiving triples in attributeFinder",e);
}
catch (URISyntaxException e){
logger.warn("Error retreiving triples in attributeFinder",e);
}
finally {}
if (results == null || results.isEmpty()) {
logger.debug("Attribute values found: 0");
return new EvaluationResult(BagAttribute.createEmptyBag(type));
}
Set<AttributeValue> bagValues = new HashSet<AttributeValue>();
logger.debug("Attribute values found: " + results.size());
for (String s : results) {
AttributeValue attributeValue = null;
try {
attributeValue = m_attributeFactory.createValue(type, s);
} catch (Exception e) {
logger.error("Error creating attribute: " + e.getMessage(), e);
continue;
}
bagValues.add(attributeValue);
if (logger.isDebugEnabled()) {
logger.debug("AttributeValue found: [" + type.toASCIIString()
+ "] " + s);
}
}
BagAttribute bag = new BagAttribute(type, bagValues);
return new EvaluationResult(bag);
}
}