com.qq.weixin.mp.aes.XMLParse Maven / Gradle / Ivy
/**
* 对企业微信发送给企业后台的消息加解密示例代码.
*
* @copyright Copyright (c) 1998-2014 Tencent Inc.
*/
// ------------------------------------------------------------------------
package com.qq.weixin.mp.aes;
import java.io.StringReader;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.NodeList;
import org.xml.sax.InputSource;
/**
* XMLParse class
*
* 提供提取消息格式中的密文及生成回复消息格式的接口.
*/
class XMLParse {
/**
* 提取出xml数据包中的加密消息
* @param xmltext 待提取的xml字符串
* @return 提取出的加密消息字符串
* @throws AesException
*/
public static Object[] extract(String xmltext) throws AesException {
Object[] result = new Object[3];
try {
DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
String FEATURE = null;
// This is the PRIMARY defense. If DTDs (doctypes) are disallowed, almost all XML entity attacks are prevented
// Xerces 2 only - http://xerces.apache.org/xerces2-j/features.html#disallow-doctype-decl
FEATURE = "http://apache.org/xml/features/disallow-doctype-decl";
dbf.setFeature(FEATURE, true);
// If you can't completely disable DTDs, then at least do the following:
// Xerces 1 - http://xerces.apache.org/xerces-j/features.html#external-general-entities
// Xerces 2 - http://xerces.apache.org/xerces2-j/features.html#external-general-entities
// JDK7+ - http://xml.org/sax/features/external-general-entities
FEATURE = "http://xml.org/sax/features/external-general-entities";
dbf.setFeature(FEATURE, false);
// Xerces 1 - http://xerces.apache.org/xerces-j/features.html#external-parameter-entities
// Xerces 2 - http://xerces.apache.org/xerces2-j/features.html#external-parameter-entities
// JDK7+ - http://xml.org/sax/features/external-parameter-entities
FEATURE = "http://xml.org/sax/features/external-parameter-entities";
dbf.setFeature(FEATURE, false);
// Disable external DTDs as well
FEATURE = "http://apache.org/xml/features/nonvalidating/load-external-dtd";
dbf.setFeature(FEATURE, false);
// and these as well, per Timothy Morgan's 2014 paper: "XML Schema, DTD, and Entity Attacks"
dbf.setXIncludeAware(false);
dbf.setExpandEntityReferences(false);
// And, per Timothy Morgan: "If for some reason support for inline DOCTYPEs are a requirement, then
// ensure the entity settings are disabled (as shown above) and beware that SSRF attacks
// (http://cwe.mitre.org/data/definitions/918.html) and denial
// of service attacks (such as billion laughs or decompression bombs via "jar:") are a risk."
// remaining parser logic
DocumentBuilder db = dbf.newDocumentBuilder();
StringReader sr = new StringReader(xmltext);
InputSource is = new InputSource(sr);
Document document = db.parse(is);
Element root = document.getDocumentElement();
NodeList nodelist1 = root.getElementsByTagName("Encrypt");
result[0] = 0;
result[1] = nodelist1.item(0).getTextContent();
return result;
} catch (Exception e) {
e.printStackTrace();
throw new AesException(AesException.ParseXmlError);
}
}
/**
* 生成xml消息
* @param encrypt 加密后的消息密文
* @param signature 安全签名
* @param timestamp 时间戳
* @param nonce 随机字符串
* @return 生成的xml字符串
*/
public static String generate(String encrypt, String signature, String timestamp, String nonce) {
String format = "\n" + "%3$s \n" + " ";
return String.format(format, encrypt, signature, timestamp, nonce);
}
}