Java tutorial
/* * Copyright 1999-2009 The Apache Software Foundation. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. * * DSS - Digital Signature Services * * Copyright (C) 2013 European Commission, Directorate-General Internal Market and Services (DG MARKT), B-1049 Bruxelles/Brussel * * Developed by: 2013 ARHS Developments S.A. (rue Nicolas Bov 2B, L-1253 Luxembourg) http://www.arhs-developments.com * * This file is part of the "DSS - Digital Signature Services" project. * * "DSS - Digital Signature Services" is free software: you can redistribute it and/or modify it under the terms of * the GNU Lesser General Public License as published by the Free Software Foundation, either version 2.1 of the * License, or (at your option) any later version. * * DSS is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public License along with * "DSS - Digital Signature Services". If not, see <http://www.gnu.org/licenses/>. */ package eu.europa.ec.markt.dss.validation102853.toolbox; import java.io.UnsupportedEncodingException; import java.net.URLDecoder; import java.util.HashSet; import java.util.Set; import javax.xml.xpath.XPath; import javax.xml.xpath.XPathConstants; import javax.xml.xpath.XPathExpressionException; import javax.xml.xpath.XPathFactory; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.apache.xml.security.signature.XMLSignatureInput; import org.apache.xml.security.utils.resolver.ResourceResolverContext; import org.apache.xml.security.utils.resolver.ResourceResolverException; import org.apache.xml.security.utils.resolver.ResourceResolverSpi; import org.w3c.dom.Attr; import org.w3c.dom.Node; import org.w3c.dom.NodeList; /** * An implementation of a resource resolver, which evaluates xpointer expressions. * * @author wglas * Adapted by * @author Robert Bielecki */ public class XPointerResourceResolver extends ResourceResolverSpi { private static Log LOG = LogFactory.getLog(XPointerResourceResolver.class); private static final String XP_OPEN = "xpointer("; private static final String XNS_OPEN = "xmlns("; private XPathFactory xPathFactory; private Node baseNode; public XPointerResourceResolver(Node baseNode) { this.xPathFactory = XPathFactory.newInstance(); this.baseNode = baseNode; } @Override public boolean engineCanResolveURI(final ResourceResolverContext context) { final Attr uriAttr = context.attr; final String uri = uriAttr.getNodeValue(); final boolean xPointerQuery = isXPointerQuery(uri, false); if (LOG.isDebugEnabled()) { LOG.debug("I state that I " + (xPointerQuery ? "can" : "cannot") + " resolve Uri/Base Uri:'" + uri + "/" + context.baseUri + "'"); } return xPointerQuery; } /** * Indicates if the given URI is an XPointer query. * * @param uriValue URI to be analysed * @return true if it is an XPointer query */ public static boolean isXPointerQuery(String uriValue, final boolean strict) { if (uriValue.isEmpty() || uriValue.charAt(0) != '#') { return false; } final String decodedUri; try { decodedUri = URLDecoder.decode(uriValue, "utf-8"); } catch (UnsupportedEncodingException e) { LOG.warn("utf-8 not a valid encoding", e); return false; } final String parts[] = decodedUri.substring(1).split("\\s"); // plain ID reference. if (parts.length == 1 && !parts[0].startsWith(XNS_OPEN)) { return strict ? false : true; } int ii = 0; for (; ii < parts.length - 1; ++ii) { if (!parts[ii].endsWith(")") || !parts[ii].startsWith(XNS_OPEN)) { return false; } } if (!parts[ii].endsWith(")") || !parts[ii].startsWith(XP_OPEN)) { return false; } return true; } @Override public XMLSignatureInput engineResolveURI(ResourceResolverContext context) throws ResourceResolverException { final Attr uriAttr = context.attr; final String baseUri = context.baseUri; String uriNodeValue = uriAttr.getNodeValue(); if (uriNodeValue.charAt(0) != '#') { return null; } String xpURI; try { xpURI = URLDecoder.decode(uriNodeValue, "utf-8"); } catch (UnsupportedEncodingException e) { LOG.warn("utf-8 not a valid encoding", e); return null; } String parts[] = xpURI.substring(1).split("\\s"); int i = 0; DSigNamespaceContext nsContext = null; if (parts.length > 1) { nsContext = new DSigNamespaceContext(); for (; i < parts.length - 1; ++i) { if (!parts[i].endsWith(")") || !parts[i].startsWith(XNS_OPEN)) { return null; } String mapping = parts[i].substring(XNS_OPEN.length(), parts[i].length() - 1); int pos = mapping.indexOf('='); if (pos <= 0 || pos >= mapping.length() - 1) { throw new ResourceResolverException("malformed namespace part of XPointer expression", uriNodeValue, baseUri); } nsContext.addNamespace(mapping.substring(0, pos), mapping.substring(pos + 1)); } } try { Node node = null; NodeList nodes = null; // plain ID reference. if (i == 0 && !parts[i].startsWith(XP_OPEN)) { node = this.baseNode.getOwnerDocument().getElementById(parts[i]); } else { if (!parts[i].endsWith(")") || !parts[i].startsWith(XP_OPEN)) { return null; } XPath xp = this.xPathFactory.newXPath(); if (nsContext != null) { xp.setNamespaceContext(nsContext); } nodes = (NodeList) xp.evaluate(parts[i].substring(XP_OPEN.length(), parts[i].length() - 1), this.baseNode, XPathConstants.NODESET); if (nodes.getLength() == 0) { return null; } if (nodes.getLength() == 1) { node = nodes.item(0); } } XMLSignatureInput result = null; if (node != null) { result = new XMLSignatureInput(node); } else if (nodes != null) { Set<Node> nodeSet = new HashSet<Node>(nodes.getLength()); for (int j = 0; j < nodes.getLength(); ++j) { nodeSet.add(nodes.item(j)); } result = new XMLSignatureInput(nodeSet); } else { return null; } result.setMIMEType("text/xml"); result.setExcludeComments(true); result.setSourceURI((baseUri != null) ? baseUri.concat(uriNodeValue) : uriNodeValue); return result; } catch (XPathExpressionException e) { throw new ResourceResolverException("malformed XPath inside XPointer expression", e, uriNodeValue, baseUri); } } }