/*
* EncryptedDataSAXParser.java
* PROJECT: JDigiDoc
* DESCRIPTION: Digi Doc functions for creating
* and reading encrypted documents. Implementation using SAX parser.
* AUTHOR: Veiko Sinivee, S|E|B IT Partner Estonia
*==================================================
* Copyright (C) AS Sertifitseerimiskeskus
* This library 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.
* This library 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.
* GNU Lesser General Public Licence is available at
* http://www.gnu.org/copyleft/lesser.html
*==================================================
*/
package ee.sk.xmlenc.factory;
import java.io.InputStream;
import ee.sk.digidoc.DigiDocException;
import ee.sk.digidoc.factory.SAXDigiDocException;
import ee.sk.digidoc.SignedDoc;
import ee.sk.digidoc.Base64Util;
import ee.sk.xmlenc.EncryptedData;
import ee.sk.xmlenc.EncryptedKey;
import ee.sk.xmlenc.EncryptionProperty;
import java.io.FileInputStream;
//import java.io.InputStream;
import java.util.Stack;
import org.xml.sax.SAXException;
import org.xml.sax.Attributes;
import org.xml.sax.helpers.DefaultHandler;
import javax.xml.parsers.SAXParserFactory;
import javax.xml.parsers.SAXParser;
import java.security.cert.X509Certificate;
import org.apache.log4j.Logger;
/**
* Implementation class for reading and writing
* encrypted files using a SAX parser
* @author Veiko Sinivee
* @version 1.0
*/
public class EncryptedDataSAXParser
extends DefaultHandler
implements EncryptedDataParser
{
private Stack m_tags;
private EncryptedData m_doc;
private StringBuffer m_sbCollectChars;
/** log4j logger */
private Logger m_logger = null;
/**
* Creates new EncyptedDataSAXParser
* and initializes the variables
*/
public EncryptedDataSAXParser() {
m_tags = new Stack();
m_doc = null;
m_sbCollectChars = null;
m_logger = Logger.getLogger(EncryptedDataSAXParser.class);
}
/**
* initializes the implementation class
* @see ee.sk.xmlenc.factory.EncryptedDataParser#init()
*/
public void init() throws DigiDocException {
}
/**
* Reads in a EncryptedData file (.cdoc)
* @param dencStream opened stream with EncrypyedData data
* The user must open and close it.
* @return EncryptedData object if successfully parsed
* @see ee.sk.xmlenc.factory.EncryptedDataParser#readEncryptedData(java.io.InputStream)
*/
public EncryptedData readEncryptedData(InputStream dencStream)
throws DigiDocException
{
// Use an instance of ourselves as the SAX event handler
EncryptedDataSAXParser handler = this;
// Use the default (non-validating) parser
SAXParserFactory factory = SAXParserFactory.newInstance();
//factory.setNamespaceAware(true);
try {
factory.setFeature("http://xml.org/sax/features/external-general-entities", false);
factory.setFeature("http://xml.org/sax/features/external-parameter-entities", false);
SAXParser saxParser = factory.newSAXParser();
saxParser.parse(dencStream, handler);
} catch (SAXDigiDocException ex) {
throw ex.getDigiDocException();
} catch (Exception ex) {
DigiDocException.handleException(ex,
DigiDocException.ERR_PARSE_XML);
}
if (m_doc == null)
throw new DigiDocException(DigiDocException.ERR_DIGIDOC_FORMAT,
"This document is not in EncryptedData format", null);
return m_doc;
}
/**
* Reads in a EncryptedData file
* @param fileName file name
* @return EncryptedData document object if successfully parsed
*/
public EncryptedData readEncryptedData(String fileName)
throws DigiDocException
{
// Use an instance of ourselves as the SAX event handler
EncryptedDataSAXParser handler = this;
// Use the default (non-validating) parser
SAXParserFactory factory = SAXParserFactory.newInstance();
//factory.setNamespaceAware(true);
try {
factory.setFeature("http://xml.org/sax/features/external-general-entities", false);
factory.setFeature("http://xml.org/sax/features/external-parameter-entities", false);
SAXParser saxParser = factory.newSAXParser();
FileInputStream is = new FileInputStream(fileName);
saxParser.parse(is, handler);
is.close();
} catch (SAXDigiDocException ex) {
throw ex.getDigiDocException();
} catch (Exception ex) {
DigiDocException.handleException(
ex, DigiDocException.ERR_PARSE_XML);
}
if (m_doc == null)
throw new DigiDocException(
DigiDocException.ERR_DIGIDOC_FORMAT,
"This document is not in EncryptedData format", null);
return m_doc;
}
/**
* Start Document handler
*/
public void startDocument() throws SAXException {
m_doc = null;
m_sbCollectChars = null;
}
/**
* End Document handler
*/
public void endDocument() throws SAXException {
}
/**
* Finds the value of an atribute by name
* @param atts atributes
* @param attName name of atribute
* @return value of the atribute
*/
private String findAtributeValue(Attributes attrs, String attName) {
String value = null;
for (int i = 0; i < attrs.getLength(); i++) {
String key = attrs.getQName(i);
if (key.equals(attName) || key.indexOf(attName) != -1) {
value = attrs.getValue(i);
break;
}
}
return value;
}
/**
* Checks if this document is in <EncryptedData> format
* @throws SAXDigiDocException if the document is not in <EncryptedData> format
*/
private void checkEncryptedData()
throws SAXDigiDocException
{
if(m_doc == null)
throw new SAXDigiDocException(DigiDocException.ERR_XMLENC_NO_ENCRYPTED_DATA,
"This document is not in EncryptedData format!");
}
/**
* Checks if the <EncryptedKey> objects exists
* @throws SAXDigiDocException if the objects <EncryptedKey> does not exist
*/
private void checkEncryptedKey(EncryptedKey key)
throws SAXDigiDocException
{
if(key == null)
throw new SAXDigiDocException(DigiDocException.ERR_XMLENC_NO_ENCRYPTED_KEY,
"This <EncryptedKey> object does not exist!");
}
/**
* Start Element handler
* @param namespaceURI namespace URI
* @param lName local name
* @param qName qualified name
* @param attrs attributes
*/
public void startElement(String namespaceURI, String lName, String qName, Attributes attrs)
throws SAXDigiDocException
{
String tName = qName;
if(tName.indexOf(":") != -1)
tName = qName.substring(qName.indexOf(":")+1);
if (m_logger.isDebugEnabled())
m_logger.debug("Start Element: " + tName + " qname: " + qName + " lname: " + lName + " uri: " + namespaceURI);
m_tags.push(tName);
if (tName.equals("KeyName") ||
tName.equals("CarriedKeyName") ||
tName.equals("X509Certificate") ||
tName.equals("CipherValue") ||
tName.equals("EncryptionProperty") )
m_sbCollectChars = new StringBuffer();
// <EncryptedData>
if(tName.equals("EncryptedData")) {
String str = findAtributeValue(attrs, "xmlns");
try {
m_doc = new EncryptedData(str);
str = findAtributeValue(attrs, "Id");
if(str != null)
m_doc.setId(str);
str = findAtributeValue(attrs, "Type");
if(str != null)
m_doc.setType(str);
str = findAtributeValue(attrs, "MimeType");
if(str != null)
m_doc.setMimeType(str);
} catch (DigiDocException ex) {
SAXDigiDocException.handleException(ex);
}
}
// <EncryptionMethod>
if(tName.equals("EncryptionMethod")) {
checkEncryptedData();
if (m_tags.search("EncryptedKey") != -1) { // child of <EncryptedKey>
EncryptedKey ekey = m_doc.getLastEncryptedKey();
checkEncryptedKey(ekey);
try {
ekey.setEncryptionMethod(findAtributeValue(attrs, "Algorithm"));
} catch (DigiDocException ex) {
SAXDigiDocException.handleException(ex);
}
} else { // child of <EncryptedData>
try {
m_doc.setEncryptionMethod(findAtributeValue(attrs, "Algorithm"));
} catch (DigiDocException ex) {
SAXDigiDocException.handleException(ex);
}
}
}
// <EncryptedKey>
if(tName.equals("EncryptedKey")) {
checkEncryptedData();
EncryptedKey ekey = new EncryptedKey();
m_doc.addEncryptedKey(ekey);
String str = findAtributeValue(attrs, "Recipient");
if(str != null)
ekey.setRecipient(str);
str = findAtributeValue(attrs, "Id");
if(str != null)
ekey.setId(str);
}
// <EncryptionProperties>
if(tName.equals("EncryptionProperties")) {
checkEncryptedData();
String str =findAtributeValue(attrs, "Id");
if(str != null)
m_doc.setEncryptionPropertiesId(str);
}
// <EncryptionProperty>
if(tName.equals("EncryptionProperty")) {
checkEncryptedData();
EncryptionProperty eprop = new EncryptionProperty();
m_doc.addProperty(eprop);
String str =findAtributeValue(attrs, "Id");
if(str != null)
eprop.setId(str);
str =findAtributeValue(attrs, "Target");
if(str != null)
eprop.setTarget(str);
str =findAtributeValue(attrs, "Name");
try {
if(str != null)
eprop.setName(str);
} catch (DigiDocException ex) {
SAXDigiDocException.handleException(ex);
}
}
}
/**
* End Element handler
* @param namespaceURI namespace URI
* @param lName local name
* @param qName qualified name
*/
public void endElement(String namespaceURI, String sName, String qName)
throws SAXException
{
String tName = qName;
if(tName.indexOf(":") != -1)
tName = qName.substring(tName.indexOf(":")+1);
if(m_logger.isDebugEnabled())
m_logger.debug("End Element: " + tName);
// remove last tag from stack
String currTag = (String) m_tags.pop();
// <KeyName>
if(tName.equals("KeyName")) {
checkEncryptedData();
EncryptedKey ekey = m_doc.getLastEncryptedKey();
checkEncryptedKey(ekey);
ekey.setKeyName(m_sbCollectChars.toString());
m_sbCollectChars = null; // stop collecting
}
// <CarriedKeyName>
if(tName.equals("CarriedKeyName")) {
checkEncryptedData();
EncryptedKey ekey = m_doc.getLastEncryptedKey();
checkEncryptedKey(ekey);
ekey.setCarriedKeyName(m_sbCollectChars.toString());
m_sbCollectChars = null; // stop collecting
}
// <X509Certificate>
if(tName.equals("X509Certificate")) {
checkEncryptedData();
EncryptedKey ekey = m_doc.getLastEncryptedKey();
checkEncryptedKey(ekey);
try {
X509Certificate cert = SignedDoc.readCertificate(Base64Util.
decode(m_sbCollectChars.toString().getBytes()));
ekey.setRecipientsCertificate(cert);
} catch (DigiDocException ex) {
SAXDigiDocException.handleException(ex);
}
m_sbCollectChars = null; // stop collecting
}
// <CipherValue>
if(tName.equals("CipherValue")) {
checkEncryptedData();
if (m_tags.search("EncryptedKey") != -1) { // child of <EncryptedKey>
EncryptedKey ekey = m_doc.getLastEncryptedKey();
checkEncryptedKey(ekey);
ekey.setTransportKeyData(Base64Util.
decode(m_sbCollectChars.toString().getBytes()));
} else { // child of <EncryptedData>
m_doc.setData(Base64Util.
decode(m_sbCollectChars.toString().getBytes()));
if(m_doc.getMimeType() != null &&
m_doc.getMimeType().equals(EncryptedData.DENC_ENCDATA_MIME_ZLIB))
m_doc.setDataStatus(EncryptedData.DENC_DATA_STATUS_ENCRYPTED_AND_COMPRESSED);
else
m_doc.setDataStatus(EncryptedData.DENC_DATA_STATUS_ENCRYPTED_AND_NOT_COMPRESSED); // ???
}
m_sbCollectChars = null; // stop collecting
}
// <EncryptionProperty>
if(tName.equals("EncryptionProperty")) {
checkEncryptedData();
EncryptionProperty eprop = m_doc.getLastProperty();
try {
if(eprop != null && m_sbCollectChars != null)
eprop.setContent(m_sbCollectChars.toString());
} catch (DigiDocException ex) {
SAXDigiDocException.handleException(ex);
}
m_sbCollectChars = null; // stop collecting
}
}
/**
* SAX characters event handler
* @param buf received bytes array
* @param offset offset to the array
* @param len length of data
*/
public void characters(char buf[], int offset, int len)
throws SAXException {
String s = new String(buf, offset, len);
// just collect the data since it could
// be on many lines and be processed in many events
if (s != null) {
if (m_sbCollectChars != null)
m_sbCollectChars.append(s);
}
}
}