package org.openid4java.discovery.xrds;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.openid4java.OpenIDException;
import org.openid4java.discovery.Discovery;
import org.openid4java.discovery.DiscoveryException;
import org.openid4java.discovery.RuntimeDiscoveryException;
import org.w3c.dom.Document;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.*;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.util.*;
/**
* @author jbufu
*/
public class XrdsParserImpl implements XrdsParser
{
private static final Log _log = LogFactory.getLog(XrdsParserImpl.class);
private static final boolean DEBUG = _log.isDebugEnabled();
private static final String W3C_XML_SCHEMA = "http://www.w3.org/2001/XMLSchema";
private static final String JAXP_SCHEMA_LANGUAGE = "http://java.sun.com/xml/jaxp/properties/schemaLanguage";
private static final String JAXP_SCHEMA_SOURCE = "http://java.sun.com/xml/jaxp/properties/schemaSource";
private static final String XRDS_SCHEMA = "xrds.xsd";
private static final String XRD_SCHEMA = "xrd.xsd";
private static final String XRD_NS = "xri://$xrd*($v*2.0)";
private static final String XRD_ELEM_XRD = "XRD";
private static final String XRD_ELEM_TYPE = "Type";
private static final String XRD_ELEM_URI = "URI";
private static final String XRD_ELEM_LOCALID = "LocalID";
private static final String XRD_ELEM_CANONICALID = "CanonicalID";
private static final String XRD_ATTR_PRIORITY = "priority";
private static final String OPENID_NS = "http://openid.net/xmlns/1.0";
private static final String OPENID_ELEM_DELEGATE = "Delegate";
public List parseXrds(String input, Set targetTypes) throws DiscoveryException
{
if (DEBUG)
_log.debug("Parsing XRDS input for service types: " + targetTypes.toString());
Document document = parseXmlInput(input);
NodeList XRDs = document.getElementsByTagNameNS(XRD_NS, XRD_ELEM_XRD);
Node lastXRD;
if (XRDs.getLength() < 1 || (lastXRD = XRDs.item(XRDs.getLength() - 1)) == null)
throw new DiscoveryException("No XRD elements found.");
// get the canonical ID, if any (needed for XRIs)
String canonicalId = null;
Node canonicalIdNode;
NodeList canonicalIDs = document.getElementsByTagNameNS(XRD_NS, XRD_ELEM_CANONICALID);
for (int i = 0; i < canonicalIDs.getLength(); i++) {
canonicalIdNode = canonicalIDs.item(i);
if (canonicalIdNode.getParentNode() != lastXRD) continue;
if (canonicalId != null)
throw new DiscoveryException("More than one Canonical ID found.");
canonicalId = canonicalIdNode.getFirstChild() != null && canonicalIdNode.getFirstChild().getNodeType() == Node.TEXT_NODE ?
canonicalIdNode.getFirstChild().getNodeValue() : null;
}
// extract the services that match the specified target types
NodeList types = document.getElementsByTagNameNS(XRD_NS, XRD_ELEM_TYPE);
Map serviceTypes = new HashMap();
Set selectedServices = new HashSet();
Node typeNode, serviceNode;
for (int i = 0; i < types.getLength(); i++) {
typeNode = types.item(i);
String type = typeNode != null && typeNode.getFirstChild() != null && typeNode.getFirstChild().getNodeType() == Node.TEXT_NODE ?
typeNode.getFirstChild().getNodeValue() : null;
if (type == null) continue;
serviceNode = typeNode.getParentNode();
if (serviceNode.getParentNode() != lastXRD) continue;
if (targetTypes.contains(type))
selectedServices.add(serviceNode);
addServiceType(serviceTypes, serviceNode, type);
}
if (DEBUG)
_log.debug("Found " + serviceTypes.size() + " services for the requested types.");
// extract local IDs
Map serviceLocalIDs = extractElementsByParent(XRD_NS, XRD_ELEM_LOCALID, selectedServices, document);
Map serviceDelegates = extractElementsByParent(OPENID_NS, OPENID_ELEM_DELEGATE, selectedServices, document);
// build XrdsServiceEndpoints for all URIs in the found services
List result = new ArrayList();
NodeList uris = document.getElementsByTagNameNS(XRD_NS, XRD_ELEM_URI);
Node uriNode;
for (int i = 0; i < uris.getLength(); i++) {
uriNode = uris.item(i);
if (uriNode == null || !selectedServices.contains(uriNode.getParentNode())) continue;
String uri = uriNode.getFirstChild() != null && uriNode.getFirstChild().getNodeType() == Node.TEXT_NODE ?
uriNode.getFirstChild().getNodeValue() : null;
serviceNode = uriNode.getParentNode();
Set typeSet = (Set) serviceTypes.get(serviceNode);
String localId = (String) serviceLocalIDs.get(serviceNode);
String delegate = (String) serviceDelegates.get(serviceNode);
XrdsServiceEndpoint endpoint = new XrdsServiceEndpoint(uri, typeSet, getPriority(serviceNode), getPriority(uriNode), localId, delegate, canonicalId);
if (DEBUG)
_log.debug("Discovered endpoint: \n" + endpoint);
result.add(endpoint);
}
Collections.sort(result);
return result;
}
private Map extractElementsByParent(String ns, String elem, Set parents, Document document)
{
Map result = new HashMap();
NodeList nodes = document.getElementsByTagNameNS(ns, elem);
Node node;
for (int i = 0; i < nodes.getLength(); i++) {
node = nodes.item(i);
if (node == null || !parents.contains(node.getParentNode())) continue;
String localId = node.getFirstChild() != null && node.getFirstChild().getNodeType() == Node.TEXT_NODE ?
node.getFirstChild().getNodeValue() : null;
result.put(node.getParentNode(), localId);
}
return result;
}
private int getPriority(Node node)
{
if (node.hasAttributes())
{
Node priority = node.getAttributes().getNamedItem(XRD_ATTR_PRIORITY);
if (priority != null)
return Integer.parseInt(priority.getNodeValue());
else
return XrdsServiceEndpoint.LOWEST_PRIORITY;
}
return 0;
}
private Document parseXmlInput(String input) throws DiscoveryException
{
if (input == null)
throw new DiscoveryException("Cannot read XML message",
OpenIDException.XRDS_DOWNLOAD_ERROR);
if (DEBUG)
_log.debug("Parsing XRDS input: " + input);
try
{
DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
dbf.setNamespaceAware(true);
dbf.setValidating(true);
dbf.setExpandEntityReferences(false);
dbf.setFeature("http://xml.org/sax/features/validation", true);
dbf.setFeature("http://xml.org/sax/features/external-general-entities", false);
dbf.setFeature("http://xml.org/sax/features/external-parameter-entities", false);
dbf.setFeature("http://apache.org/xml/features/nonvalidating/load-dtd-grammar", false);
dbf.setFeature("http://apache.org/xml/features/nonvalidating/load-external-dtd", false);
dbf.setAttribute(JAXP_SCHEMA_LANGUAGE, W3C_XML_SCHEMA);
dbf.setAttribute(JAXP_SCHEMA_SOURCE, new Object[] {
Discovery.class.getResourceAsStream(XRD_SCHEMA),
Discovery.class.getResourceAsStream(XRDS_SCHEMA),
});
DocumentBuilder builder = dbf.newDocumentBuilder();
builder.setErrorHandler(new ErrorHandler() {
public void error(SAXParseException exception) throws SAXException {
throw exception;
}
public void fatalError(SAXParseException exception) throws SAXException {
throw exception;
}
public void warning(SAXParseException exception) throws SAXException {
throw exception;
}
});
builder.setEntityResolver(new EntityResolver() {
public InputSource resolveEntity(String publicId, String systemId) throws SAXException, IOException {
throw new RuntimeDiscoveryException("External entity found in XRDS data");
}
});
return builder.parse(new ByteArrayInputStream(input.getBytes()));
}
catch (ParserConfigurationException e)
{
throw new DiscoveryException("Parser configuration error",
OpenIDException.XRDS_PARSING_ERROR, e);
}
catch (SAXException e)
{
throw new DiscoveryException("Error parsing XML document",
OpenIDException.XRDS_PARSING_ERROR, e);
}
catch (IOException e)
{
throw new DiscoveryException("Error reading XRDS document",
OpenIDException.XRDS_DOWNLOAD_ERROR, e);
}
catch (RuntimeDiscoveryException rde)
{
throw new DiscoveryException(rde.getMessage());
}
}
private void addServiceType(Map serviceTypes, Node serviceNode, String type)
{
Set types = (Set) serviceTypes.get(serviceNode);
if (types == null)
{
types = new HashSet();
serviceTypes.put(serviceNode, types);
}
types.add(type);
}
}