Java tutorial
/** * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you 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. */ package org.apache.xml.security.c14n.implementations; import java.io.IOException; import java.net.URI; import java.net.URISyntaxException; import java.util.ArrayList; import java.util.Collection; import java.util.HashMap; import java.util.Iterator; import java.util.List; import java.util.Map; import java.util.Set; import java.util.SortedSet; import java.util.TreeSet; import javax.xml.parsers.ParserConfigurationException; import org.w3c.dom.Attr; import org.w3c.dom.Document; import org.w3c.dom.Element; import org.w3c.dom.NamedNodeMap; import org.w3c.dom.Node; import org.xml.sax.SAXException; import org.apache.xml.security.c14n.CanonicalizationException; import org.apache.xml.security.c14n.helper.C14nHelper; import org.apache.xml.security.signature.XMLSignatureInput; import org.apache.xml.security.utils.Constants; import org.apache.xml.security.utils.XMLUtils; /** * Implements <A HREF="http://www.w3.org/TR/2008/PR-xml-c14n11-20080129/"> * Canonical XML Version 1.1</A>, a W3C Proposed Recommendation from 29 * January 2008. * * @author Sean Mullan * @author Raul Benito */ public abstract class Canonicalizer11 extends CanonicalizerBase { private static final String XMLNS_URI = Constants.NamespaceSpecNS; private static final String XML_LANG_URI = Constants.XML_LANG_SPACE_SpecNS; private static org.apache.commons.logging.Log log = org.apache.commons.logging.LogFactory .getLog(Canonicalizer11.class); private final SortedSet<Attr> result = new TreeSet<Attr>(COMPARE); private boolean firstCall = true; private static class XmlAttrStack { static class XmlsStackElement { int level; boolean rendered = false; List<Attr> nodes = new ArrayList<Attr>(); }; int currentLevel = 0; int lastlevel = 0; XmlsStackElement cur; List<XmlsStackElement> levels = new ArrayList<XmlsStackElement>(); void push(int level) { currentLevel = level; if (currentLevel == -1) { return; } cur = null; while (lastlevel >= currentLevel) { levels.remove(levels.size() - 1); int newSize = levels.size(); if (newSize == 0) { lastlevel = 0; return; } lastlevel = (levels.get(newSize - 1)).level; } } void addXmlnsAttr(Attr n) { if (cur == null) { cur = new XmlsStackElement(); cur.level = currentLevel; levels.add(cur); lastlevel = currentLevel; } cur.nodes.add(n); } void getXmlnsAttr(Collection<Attr> col) { int size = levels.size() - 1; if (cur == null) { cur = new XmlsStackElement(); cur.level = currentLevel; lastlevel = currentLevel; levels.add(cur); } boolean parentRendered = false; XmlsStackElement e = null; if (size == -1) { parentRendered = true; } else { e = levels.get(size); if (e.rendered && e.level + 1 == currentLevel) { parentRendered = true; } } if (parentRendered) { col.addAll(cur.nodes); cur.rendered = true; return; } Map<String, Attr> loa = new HashMap<String, Attr>(); List<Attr> baseAttrs = new ArrayList<Attr>(); boolean successiveOmitted = true; for (; size >= 0; size--) { e = levels.get(size); if (e.rendered) { successiveOmitted = false; } Iterator<Attr> it = e.nodes.iterator(); while (it.hasNext() && successiveOmitted) { Attr n = it.next(); if (n.getLocalName().equals("base") && !e.rendered) { baseAttrs.add(n); } else if (!loa.containsKey(n.getName())) { loa.put(n.getName(), n); } } } if (!baseAttrs.isEmpty()) { Iterator<Attr> it = col.iterator(); String base = null; Attr baseAttr = null; while (it.hasNext()) { Attr n = it.next(); if (n.getLocalName().equals("base")) { base = n.getValue(); baseAttr = n; break; } } it = baseAttrs.iterator(); while (it.hasNext()) { Attr n = it.next(); if (base == null) { base = n.getValue(); baseAttr = n; } else { try { base = joinURI(n.getValue(), base); } catch (URISyntaxException ue) { ue.printStackTrace(); } } } if (base != null && base.length() != 0) { baseAttr.setValue(base); col.add(baseAttr); } } cur.rendered = true; col.addAll(loa.values()); } }; private XmlAttrStack xmlattrStack = new XmlAttrStack(); /** * Constructor Canonicalizer11 * * @param includeComments */ public Canonicalizer11(boolean includeComments) { super(includeComments); } /** * Always throws a CanonicalizationException because this is inclusive c14n. * * @param xpathNodeSet * @param inclusiveNamespaces * @return none it always fails * @throws CanonicalizationException always */ public byte[] engineCanonicalizeXPathNodeSet(Set<Node> xpathNodeSet, String inclusiveNamespaces) throws CanonicalizationException { throw new CanonicalizationException("c14n.Canonicalizer.UnsupportedOperation"); } /** * Always throws a CanonicalizationException because this is inclusive c14n. * * @param rootNode * @param inclusiveNamespaces * @return none it always fails * @throws CanonicalizationException */ public byte[] engineCanonicalizeSubTree(Node rootNode, String inclusiveNamespaces) throws CanonicalizationException { throw new CanonicalizationException("c14n.Canonicalizer.UnsupportedOperation"); } /** * Returns the Attr[]s to be output for the given element. * <br> * The code of this method is a copy of {@link #handleAttributes(Element, * NameSpaceSymbTable)}, * whereas it takes into account that subtree-c14n is -- well -- * subtree-based. * So if the element in question isRoot of c14n, it's parent is not in the * node set, as well as all other ancestors. * * @param element * @param ns * @return the Attr[]s to be output * @throws CanonicalizationException */ @Override protected Iterator<Attr> handleAttributesSubtree(Element element, NameSpaceSymbTable ns) throws CanonicalizationException { if (!element.hasAttributes() && !firstCall) { return null; } // result will contain the attrs which have to be output final SortedSet<Attr> result = this.result; result.clear(); if (element.hasAttributes()) { NamedNodeMap attrs = element.getAttributes(); int attrsLength = attrs.getLength(); for (int i = 0; i < attrsLength; i++) { Attr attribute = (Attr) attrs.item(i); String NUri = attribute.getNamespaceURI(); String NName = attribute.getLocalName(); String NValue = attribute.getValue(); if (!XMLNS_URI.equals(NUri)) { // It's not a namespace attr node. Add to the result and continue. result.add(attribute); } else if (!(XML.equals(NName) && XML_LANG_URI.equals(NValue))) { // The default mapping for xml must not be output. Node n = ns.addMappingAndRender(NName, NValue, attribute); if (n != null) { // Render the ns definition result.add((Attr) n); if (C14nHelper.namespaceIsRelative(attribute)) { Object exArgs[] = { element.getTagName(), NName, attribute.getNodeValue() }; throw new CanonicalizationException("c14n.Canonicalizer.RelativeNamespace", exArgs); } } } } } if (firstCall) { // It is the first node of the subtree // Obtain all the namespaces defined in the parents, and added to the output. ns.getUnrenderedNodes(result); // output the attributes in the xml namespace. xmlattrStack.getXmlnsAttr(result); firstCall = false; } return result.iterator(); } /** * Returns the Attr[]s to be output for the given element. * <br> * IMPORTANT: This method expects to work on a modified DOM tree, i.e. a * DOM which has been prepared using * {@link org.apache.xml.security.utils.XMLUtils#circumventBug2650( * org.w3c.dom.Document)}. * * @param element * @param ns * @return the Attr[]s to be output * @throws CanonicalizationException */ @Override protected Iterator<Attr> handleAttributes(Element element, NameSpaceSymbTable ns) throws CanonicalizationException { // result will contain the attrs which have to be output xmlattrStack.push(ns.getLevel()); boolean isRealVisible = isVisibleDO(element, ns.getLevel()) == 1; final SortedSet<Attr> result = this.result; result.clear(); if (element.hasAttributes()) { NamedNodeMap attrs = element.getAttributes(); int attrsLength = attrs.getLength(); for (int i = 0; i < attrsLength; i++) { Attr attribute = (Attr) attrs.item(i); String NUri = attribute.getNamespaceURI(); String NName = attribute.getLocalName(); String NValue = attribute.getValue(); if (!XMLNS_URI.equals(NUri)) { //A non namespace definition node. if (XML_LANG_URI.equals(NUri)) { if (NName.equals("id")) { if (isRealVisible) { // treat xml:id like any other attribute // (emit it, but don't inherit it) result.add(attribute); } } else { xmlattrStack.addXmlnsAttr(attribute); } } else if (isRealVisible) { //The node is visible add the attribute to the list of output attributes. result.add(attribute); } } else if (!XML.equals(NName) || !XML_LANG_URI.equals(NValue)) { /* except omit namespace node with local name xml, which defines * the xml prefix, if its string value is * http://www.w3.org/XML/1998/namespace. */ // add the prefix binding to the ns symb table. if (isVisible(attribute)) { if (isRealVisible || !ns.removeMappingIfRender(NName)) { // The xpath select this node output it if needed. Node n = ns.addMappingAndRender(NName, NValue, attribute); if (n != null) { result.add((Attr) n); if (C14nHelper.namespaceIsRelative(attribute)) { Object exArgs[] = { element.getTagName(), NName, attribute.getNodeValue() }; throw new CanonicalizationException("c14n.Canonicalizer.RelativeNamespace", exArgs); } } } } else { if (isRealVisible && !XMLNS.equals(NName)) { ns.removeMapping(NName); } else { ns.addMapping(NName, NValue, attribute); } } } } } if (isRealVisible) { //The element is visible, handle the xmlns definition Attr xmlns = element.getAttributeNodeNS(XMLNS_URI, XMLNS); Node n = null; if (xmlns == null) { //No xmlns def just get the already defined. n = ns.getMapping(XMLNS); } else if (!isVisible(xmlns)) { //There is a definition but the xmlns is not selected by the xpath. //then xmlns="" n = ns.addMappingAndRender(XMLNS, "", nullNode); } //output the xmlns def if needed. if (n != null) { result.add((Attr) n); } //Float all xml:* attributes of the unselected parent elements to this one. xmlattrStack.getXmlnsAttr(result); ns.getUnrenderedNodes(result); } return result.iterator(); } protected void circumventBugIfNeeded(XMLSignatureInput input) throws CanonicalizationException, ParserConfigurationException, IOException, SAXException { if (!input.isNeedsToBeExpanded()) { return; } Document doc = null; if (input.getSubNode() != null) { doc = XMLUtils.getOwnerDocument(input.getSubNode()); } else { doc = XMLUtils.getOwnerDocument(input.getNodeSet()); } XMLUtils.circumventBug2650(doc); } protected void handleParent(Element e, NameSpaceSymbTable ns) { if (!e.hasAttributes() && e.getNamespaceURI() == null) { return; } xmlattrStack.push(-1); NamedNodeMap attrs = e.getAttributes(); int attrsLength = attrs.getLength(); for (int i = 0; i < attrsLength; i++) { Attr attribute = (Attr) attrs.item(i); String NName = attribute.getLocalName(); String NValue = attribute.getNodeValue(); if (Constants.NamespaceSpecNS.equals(attribute.getNamespaceURI())) { if (!XML.equals(NName) || !Constants.XML_LANG_SPACE_SpecNS.equals(NValue)) { ns.addMapping(NName, NValue, attribute); } } else if (!"id".equals(NName) && XML_LANG_URI.equals(attribute.getNamespaceURI())) { xmlattrStack.addXmlnsAttr(attribute); } } if (e.getNamespaceURI() != null) { String NName = e.getPrefix(); String NValue = e.getNamespaceURI(); String Name; if (NName == null || NName.equals("")) { NName = "xmlns"; Name = "xmlns"; } else { Name = "xmlns:" + NName; } Attr n = e.getOwnerDocument().createAttributeNS("http://www.w3.org/2000/xmlns/", Name); n.setValue(NValue); ns.addMapping(NName, NValue, n); } } private static String joinURI(String baseURI, String relativeURI) throws URISyntaxException { String bscheme = null; String bauthority = null; String bpath = ""; String bquery = null; // pre-parse the baseURI if (baseURI != null) { if (baseURI.endsWith("..")) { baseURI = baseURI + "/"; } URI base = new URI(baseURI); bscheme = base.getScheme(); bauthority = base.getAuthority(); bpath = base.getPath(); bquery = base.getQuery(); } URI r = new URI(relativeURI); String rscheme = r.getScheme(); String rauthority = r.getAuthority(); String rpath = r.getPath(); String rquery = r.getQuery(); String rfragment = null; String tscheme, tauthority, tpath, tquery, tfragment; if (rscheme != null && rscheme.equals(bscheme)) { rscheme = null; } if (rscheme != null) { tscheme = rscheme; tauthority = rauthority; tpath = removeDotSegments(rpath); tquery = rquery; } else { if (rauthority != null) { tauthority = rauthority; tpath = removeDotSegments(rpath); tquery = rquery; } else { if (rpath.length() == 0) { tpath = bpath; if (rquery != null) { tquery = rquery; } else { tquery = bquery; } } else { if (rpath.startsWith("/")) { tpath = removeDotSegments(rpath); } else { if (bauthority != null && bpath.length() == 0) { tpath = "/" + rpath; } else { int last = bpath.lastIndexOf('/'); if (last == -1) { tpath = rpath; } else { tpath = bpath.substring(0, last + 1) + rpath; } } tpath = removeDotSegments(tpath); } tquery = rquery; } tauthority = bauthority; } tscheme = bscheme; } tfragment = rfragment; return new URI(tscheme, tauthority, tpath, tquery, tfragment).toString(); } private static String removeDotSegments(String path) { if (log.isDebugEnabled()) { log.debug("STEP OUTPUT BUFFER\t\tINPUT BUFFER"); } // 1. The input buffer is initialized with the now-appended path // components then replace occurrences of "//" in the input buffer // with "/" until no more occurrences of "//" are in the input buffer. String input = path; while (input.indexOf("//") > -1) { input = input.replaceAll("//", "/"); } // Initialize the output buffer with the empty string. StringBuilder output = new StringBuilder(); // If the input buffer starts with a root slash "/" then move this // character to the output buffer. if (input.charAt(0) == '/') { output.append("/"); input = input.substring(1); } printStep("1 ", output.toString(), input); // While the input buffer is not empty, loop as follows while (input.length() != 0) { // 2A. If the input buffer begins with a prefix of "./", // then remove that prefix from the input buffer // else if the input buffer begins with a prefix of "../", then // if also the output does not contain the root slash "/" only, // then move this prefix to the end of the output buffer else // remove that prefix if (input.startsWith("./")) { input = input.substring(2); printStep("2A", output.toString(), input); } else if (input.startsWith("../")) { input = input.substring(3); if (!output.toString().equals("/")) { output.append("../"); } printStep("2A", output.toString(), input); // 2B. if the input buffer begins with a prefix of "/./" or "/.", // where "." is a complete path segment, then replace that prefix // with "/" in the input buffer; otherwise, } else if (input.startsWith("/./")) { input = input.substring(2); printStep("2B", output.toString(), input); } else if (input.equals("/.")) { // FIXME: what is complete path segment? input = input.replaceFirst("/.", "/"); printStep("2B", output.toString(), input); // 2C. if the input buffer begins with a prefix of "/../" or "/..", // where ".." is a complete path segment, then replace that prefix // with "/" in the input buffer and if also the output buffer is // empty, last segment in the output buffer equals "../" or "..", // where ".." is a complete path segment, then append ".." or "/.." // for the latter case respectively to the output buffer else // remove the last segment and its preceding "/" (if any) from the // output buffer and if hereby the first character in the output // buffer was removed and it was not the root slash then delete a // leading slash from the input buffer; otherwise, } else if (input.startsWith("/../")) { input = input.substring(3); if (output.length() == 0) { output.append("/"); } else if (output.toString().endsWith("../")) { output.append(".."); } else if (output.toString().endsWith("..")) { output.append("/.."); } else { int index = output.lastIndexOf("/"); if (index == -1) { output = new StringBuilder(); if (input.charAt(0) == '/') { input = input.substring(1); } } else { output = output.delete(index, output.length()); } } printStep("2C", output.toString(), input); } else if (input.equals("/..")) { // FIXME: what is complete path segment? input = input.replaceFirst("/..", "/"); if (output.length() == 0) { output.append("/"); } else if (output.toString().endsWith("../")) { output.append(".."); } else if (output.toString().endsWith("..")) { output.append("/.."); } else { int index = output.lastIndexOf("/"); if (index == -1) { output = new StringBuilder(); if (input.charAt(0) == '/') { input = input.substring(1); } } else { output = output.delete(index, output.length()); } } printStep("2C", output.toString(), input); // 2D. if the input buffer consists only of ".", then remove // that from the input buffer else if the input buffer consists // only of ".." and if the output buffer does not contain only // the root slash "/", then move the ".." to the output buffer // else delte it.; otherwise, } else if (input.equals(".")) { input = ""; printStep("2D", output.toString(), input); } else if (input.equals("..")) { if (!output.toString().equals("/")) output.append(".."); input = ""; printStep("2D", output.toString(), input); // 2E. move the first path segment (if any) in the input buffer // to the end of the output buffer, including the initial "/" // character (if any) and any subsequent characters up to, but not // including, the next "/" character or the end of the input buffer. } else { int end = -1; int begin = input.indexOf('/'); if (begin == 0) { end = input.indexOf('/', 1); } else { end = begin; begin = 0; } String segment; if (end == -1) { segment = input.substring(begin); input = ""; } else { segment = input.substring(begin, end); input = input.substring(end); } output.append(segment); printStep("2E", output.toString(), input); } } // 3. Finally, if the only or last segment of the output buffer is // "..", where ".." is a complete path segment not followed by a slash // then append a slash "/". The output buffer is returned as the result // of remove_dot_segments if (output.toString().endsWith("..")) { output.append("/"); printStep("3 ", output.toString(), input); } return output.toString(); } private static void printStep(String step, String output, String input) { if (log.isDebugEnabled()) { log.debug(" " + step + ": " + output); if (output.length() == 0) { log.debug("\t\t\t\t" + input); } else { log.debug("\t\t\t" + input); } } } }