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* reserved comment block
* DO NOT REMOVE OR ALTER!
*/
/*
* Copyright 1999-2004 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.
*
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package com.sun.org.apache.xml.internal.security.transforms.implementations;
import java.io.BufferedInputStream;
import java.io.IOException;
import java.io.OutputStream;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import com.sun.org.apache.xml.internal.security.c14n.CanonicalizationException;
import com.sun.org.apache.xml.internal.security.exceptions.Base64DecodingException;
import com.sun.org.apache.xml.internal.security.signature.XMLSignatureInput;
import com.sun.org.apache.xml.internal.security.transforms.TransformSpi;
import com.sun.org.apache.xml.internal.security.transforms.TransformationException;
import com.sun.org.apache.xml.internal.security.transforms.Transforms;
import com.sun.org.apache.xml.internal.security.utils.Base64;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.Text;
import org.xml.sax.SAXException;
/**
* Implements the <CODE>http://www.w3.org/2000/09/xmldsig#base64</CODE> decoding
* transform.
*
* <p>The normative specification for base64 decoding transforms is
* <A HREF="http://www.w3.org/TR/2001/CR-xmldsig-core-20010419/#ref-MIME">[MIME]</A>.
* The base64 Transform element has no content. The input
* is decoded by the algorithms. This transform is useful if an
* application needs to sign the raw data associated with the encoded
* content of an element. </p>
*
* <p>This transform requires an octet stream for input.
* If an XPath node-set (or sufficiently functional alternative) is
* given as input, then it is converted to an octet stream by
* performing operations logically equivalent to 1) applying an XPath
* transform with expression self::text(), then 2) taking the string-value
* of the node-set. Thus, if an XML element is identified by a barename
* XPointer in the Reference URI, and its content consists solely of base64
* encoded character data, then this transform automatically strips away the
* start and end tags of the identified element and any of its descendant
* elements as well as any descendant comments and processing instructions.
* The output of this transform is an octet stream.</p>
*
* @author Christian Geuer-Pollmann
* @see com.sun.org.apache.xml.internal.security.utils.Base64
*/
public class TransformBase64Decode extends TransformSpi {
/** Field implementedTransformURI */
public static final String implementedTransformURI =
Transforms.TRANSFORM_BASE64_DECODE;
/**
* Method engineGetURI
*
* @inheritDoc
*/
protected String engineGetURI() {
return TransformBase64Decode.implementedTransformURI;
}
/**
* Method enginePerformTransform
*
* @param input
* @return {@link XMLSignatureInput} as the result of transformation
* @inheritDoc
* @throws CanonicalizationException
* @throws IOException
* @throws TransformationException
*/
protected XMLSignatureInput enginePerformTransform(XMLSignatureInput input)
throws IOException, CanonicalizationException,
TransformationException {
return enginePerformTransform(input,null);
}
protected XMLSignatureInput enginePerformTransform(XMLSignatureInput input,
OutputStream os)
throws IOException, CanonicalizationException,
TransformationException {
try {
if (input.isElement()) {
Node el=input.getSubNode();
if (input.getSubNode().getNodeType()==Node.TEXT_NODE) {
el=el.getParentNode();
}
StringBuffer sb=new StringBuffer();
traverseElement((Element)el,sb);
if (os==null) {
byte[] decodedBytes = Base64.decode(sb.toString());
return new XMLSignatureInput(decodedBytes);
}
Base64.decode(sb.toString().getBytes(),os);
XMLSignatureInput output=new XMLSignatureInput((byte[])null);
output.setOutputStream(os);
return output;
}
if (input.isOctetStream() || input.isNodeSet()) {
if (os==null) {
byte[] base64Bytes = input.getBytes();
byte[] decodedBytes = Base64.decode(base64Bytes);
return new XMLSignatureInput(decodedBytes);
}
if (input.isByteArray() || input.isNodeSet()) {
Base64.decode(input.getBytes(),os);
} else {
Base64.decode(new BufferedInputStream(input.getOctetStreamReal())
,os);
}
XMLSignatureInput output=new XMLSignatureInput((byte[])null);
output.setOutputStream(os);
return output;
}
try {
//Exceptional case there is current not text case testing this(Before it was a
//a common case).
Document doc =
DocumentBuilderFactory.newInstance().newDocumentBuilder().parse(
input.getOctetStream());
Element rootNode = doc.getDocumentElement();
StringBuffer sb = new StringBuffer();
traverseElement(rootNode,sb);
byte[] decodedBytes = Base64.decode(sb.toString());
return new XMLSignatureInput(decodedBytes);
} catch (ParserConfigurationException e) {
throw new TransformationException("c14n.Canonicalizer.Exception",e);
} catch (SAXException e) {
throw new TransformationException("SAX exception", e);
}
} catch (Base64DecodingException e) {
throw new TransformationException("Base64Decoding", e);
}
}
void traverseElement(org.w3c.dom.Element node,StringBuffer sb) {
Node sibling=node.getFirstChild();
while (sibling!=null) {
switch (sibling.getNodeType()) {
case Node.ELEMENT_NODE:
traverseElement((Element)sibling,sb);
break;
case Node.TEXT_NODE:
sb.append(((Text)sibling).getData());
}
sibling=sibling.getNextSibling();
}
}
}