8087283: Add support for the XML Signature here() function to the JDK XPath implementation

Reviewed-by: andrew
Backport-of: 22fad64529a890dd3ae8b07c7981d9a720cf8e96

Author: Yuri Nesterenko

jaxp/src/com/sun/org/apache/xpath/internal/compiler/FunctionTable.java

@@ -1,21 +1,23 @@
 /*
- * reserved comment block
- * DO NOT REMOVE OR ALTER!
+ * Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved.
  */
-/*
- * Copyright 1999-2005 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
+/**
+ * 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
+ * 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.
+ * 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.
  */
 /*
  * $Id: FunctionTable.java,v 1.3 2005/09/28 13:49:34 pvedula Exp $
@@ -135,6 +137,9 @@ public class FunctionTable
   /** The 'unparsed-entity-uri()' id (XSLT). */
   public static final int FUNC_UNPARSED_ENTITY_URI = 36;
 
+  /** The 'here()' id (XML Signature). */
+  public static final int FUNC_HERE = 37;
+
   // Proprietary
 
   /** The 'document-location()' id (Proprietary). */
@@ -162,7 +167,7 @@ public class FunctionTable
    * Number of built in functions.  Be sure to update this as
    * built-in functions are added.
    */
-  private static final int NUM_BUILT_IN_FUNCS = 37;
+  private static final int NUM_BUILT_IN_FUNCS = 38;
 
   /**
    * Number of built-in functions that may be added.
@@ -229,6 +234,8 @@ public class FunctionTable
       com.sun.org.apache.xpath.internal.functions.FuncDoclocation.class;
     m_functions[FUNC_UNPARSED_ENTITY_URI] =
       com.sun.org.apache.xpath.internal.functions.FuncUnparsedEntityURI.class;
+    m_functions[FUNC_HERE] =
+      com.sun.org.apache.xpath.internal.functions.FuncHere.class;
   }
 
   static{
@@ -302,6 +309,8 @@ public class FunctionTable
                           new Integer(FunctionTable.FUNC_UNPARSED_ENTITY_URI));
           m_functionID.put(Keywords.FUNC_DOCLOCATION_STRING,
                           new Integer(FunctionTable.FUNC_DOCLOCATION));
+          m_functionID.put(Keywords.FUNC_HERE_STRING,
+                          new Integer(FunctionTable.FUNC_HERE));
   }
 
   public FunctionTable(){

jaxp/src/com/sun/org/apache/xpath/internal/compiler/Keywords.java

@@ -1,21 +1,23 @@
 /*
  * Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved.
  */
-/*
- * 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
+/**
+ * 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
+ * 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.
+ * 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.
  */
 /*
  * $Id: Keywords.java,v 1.2.4.1 2005/09/14 19:46:01 jeffsuttor Exp $
@@ -326,6 +328,11 @@ public class Keywords {
     public static final String FUNC_UNPARSED_ENTITY_URI_STRING
             = "unparsed-entity-uri";
 
+    /**
+     * here function string (XML Signature).
+     */
+    public static final String FUNC_HERE_STRING = "here";
+
   // Proprietary, built in functions
     /**
      * current function string (Proprietary).

jaxp/src/com/sun/org/apache/xpath/internal/functions/FuncHere.java

@@ -0,0 +1,107 @@
+/*
+ * Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved.
+ */
+/**
+ * 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 com.sun.org.apache.xpath.internal.functions;
+
+import javax.xml.transform.TransformerException;
+import org.w3c.dom.Document;
+import org.w3c.dom.Node;
+import com.sun.org.apache.xml.internal.dtm.DTM;
+import com.sun.org.apache.xpath.internal.NodeSetDTM;
+import com.sun.org.apache.xpath.internal.XPathContext;
+import com.sun.org.apache.xpath.internal.objects.XNodeSet;
+import com.sun.org.apache.xpath.internal.objects.XObject;
+import com.sun.org.apache.xpath.internal.res.XPATHErrorResources;
+
+/**
+ * Execute the XML Signature here() function.
+ */
+public final class FuncHere extends Function {
+
+    private static final long serialVersionUID = 4328660760070034592L;
+
+    @Override
+    public XObject execute(XPathContext xctxt) throws TransformerException {
+        Node xpathOwnerNode = (Node)xctxt.getOwnerObject();
+        if (xpathOwnerNode == null) {
+            return null;
+        }
+
+        int xpathOwnerNodeDTM = xctxt.getDTMHandleFromNode(xpathOwnerNode);
+        int currentNode = xctxt.getCurrentNode();
+        DTM dtm = xctxt.getDTM(currentNode);
+        int docContext = dtm.getDocument();
+
+        if (docContext == DTM.NULL) {
+            error(xctxt, XPATHErrorResources.ER_CONTEXT_HAS_NO_OWNERDOC, null);
+        }
+
+        // check whether currentNode and the node containing the XPath
+        // expression are in the same document
+        Document currentDoc = getOwnerDocument(dtm.getNode(currentNode));
+        Document xpathOwnerDoc = getOwnerDocument(xpathOwnerNode);
+
+        if (currentDoc != xpathOwnerDoc) {
+            throw new TransformerException("Owner documents differ");
+        }
+
+        XNodeSet nodes = new XNodeSet(xctxt.getDTMManager());
+        NodeSetDTM nodeSet = nodes.mutableNodeset();
+
+        int hereNode = DTM.NULL;
+
+        switch (dtm.getNodeType(xpathOwnerNodeDTM)) {
+
+            case Node.ATTRIBUTE_NODE:
+            case Node.PROCESSING_INSTRUCTION_NODE: {
+                // returns a node-set containing the attribute /  processing
+                // instruction node
+                hereNode = xpathOwnerNodeDTM;
+                nodeSet.addNode(hereNode);
+                break;
+            }
+            case Node.TEXT_NODE : {
+                // returns a node-set containing the parent element of the
+                // text node that directly bears the XPath expression
+                hereNode = dtm.getParent(xpathOwnerNodeDTM);
+                nodeSet.addNode(hereNode);
+                break;
+            }
+            default :
+                break;
+        }
+
+        /** $todo$ Do I have to do this detach() call? */
+        nodeSet.detach();
+
+        return nodes;
+    }
+
+    private static Document getOwnerDocument(Node node) {
+        if (node.getNodeType() == Node.DOCUMENT_NODE) {
+            return (Document)node;
+        }
+        return node.getOwnerDocument();
+    }
+
+    @Override
+    public void fixupVariables(java.util.Vector vars, int globalsSize) { }
+}

jdk/src/share/classes/com/sun/org/apache/xml/internal/security/utils/XalanXPathAPI.java

@@ -165,6 +165,11 @@ private XPath createXPath(String str, PrefixResolver prefixResolver) throws Tran
 
     private static synchronized void fixupFunctionTable() {
         installed = false;
+        if (new FunctionTable().functionAvailable("here")) {
+            LOG.debug("Here function already registered");
+            installed = true;
+            return;
+        }
         LOG.debug("Registering Here function");
         /**
          * Try to register our here() implementation as internal function.