package com.zemso.filter;
import java.io.IOException;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
public class XSSFilter implements Filter {
@Override
public void init(FilterConfig filterConfig) throws ServletException {
}
@Override
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
throws IOException, ServletException {
request.setCharacterEncoding("utf-8");
chain.doFilter(new XSSRequestWrapper((HttpServletRequest) request), response);
}
@Override
public void destroy() {
}
}
package com.zemso.filter;
import java.io.UnsupportedEncodingException;
import java.util.Iterator;
import java.util.Map;
import java.util.regex.Pattern;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;
public class XSSRequestWrapper extends HttpServletRequestWrapper {
private HttpServletRequest orgRequest = null;
public XSSRequestWrapper(HttpServletRequest request) {
super(request);
this.orgRequest = request;
}
/**
* 覆盖getParameter方法，将参数名和参数值都做xss & sql过滤
* 如果需要获得原始的值，则通过super.getParameterValues(name)来获
* getParameterNames,getParameterValues和getParameterMap也可能需要覆盖
*/
@Override
public String getParameter(String name) {
String[] values = this.getParameterValues(name);
if (values == null) {
return super.getParameter(name);
} else {
return values[0];
}
}
@Override
public String[] getParameterValues(String name) {
// 通过map集合获取参数
Map<String, String[]> map = this.getParameterMap();
if (map == null) {
return super.getParameterValues(name);
} else {
String[] strings = map.get(name);
return strings;
}
}
public Map<String, String[]> getParameterMap() {
try {
String method = this.orgRequest.getMethod();
if ("post".equalsIgnoreCase(method)) {
Map<String, String[]> request_map = super.getParameterMap();
Iterator iterator = request_map.entrySet().iterator();
while (iterator.hasNext()) {
Map.Entry me = (Map.Entry) iterator.next();
System.out.println(me.getKey() + ":");
String[] values = (String[]) me.getValue();
for (int i = 0; i < values.length; i++) {
values[i] = xssEncode(values[i]);
System.out.println(values[i]);
}
}
return request_map;
} else if ("get".equalsIgnoreCase(method)) {
Map<String, String[]> request_map = super.getParameterMap();
Iterator iterator = request_map.entrySet().iterator();
while (iterator.hasNext()) {
Map.Entry me = (Map.Entry) iterator.next();
System.out.println(me.getKey() + ":");
String[] values = (String[]) me.getValue();
for (int i = 0; i < values.length; i++) {
String str = new String(values[i].getBytes("iso-8859-1"), "utf-8");
values[i] = xssEncode(str);
System.out.println(values[i]);
}
}
return request_map;
}
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
return null;
}
/**
* 覆盖getHeader方法，将参数名和参数值都做xss & sql过滤。<br/>
* 如果需要获得原始的值，则通过super.getHeaders(name)来获取<br/>
* getHeaderNames 也可能需要覆盖
*/
@Override
public String getHeader(String name) {
String[] values = this.getParameterValues(name);
if (values == null) {
return super.getParameter(name);
} else {
return values[0];
}
}
/**
* 将容易引起xss & sql漏洞的半角字符直接替换成全角字符
*
* @param s
* @return
*/
private static String xssEncode(String s) {
if (s == null || s.isEmpty()) {
return s;
} else {
s = stripXSSAndSql(s);
}
StringBuilder sb = new StringBuilder(s.length() + 16);
for (int i = 0; i < s.length(); i++) {
char c = s.charAt(i);
switch (c) {
case '>':
sb.append("＞");// 转义大于号
break;
case '<':
sb.append("＜");// 转义小于号
break;
case '\'':
sb.append("＇");// 转义单引号
break;
case '\"':
sb.append("＂");// 转义双引号
break;
case '&':
sb.append("＆");// 转义&
break;
case '#':
sb.append("＃");// 转义#
break;
default:
sb.append(c);
break;
}
}
return sb.toString();
}
/**
* 获取最原始的request
*
* @return
*/
public HttpServletRequest getOrgRequest() {
return orgRequest;
}
/**
* 获取最原始的request的静态方法
*
* @return
*/
public static HttpServletRequest getOrgRequest(HttpServletRequest req) {
if (req instanceof XSSRequestWrapper) {
return ((XSSRequestWrapper) req).getOrgRequest();
}
return req;
}
/**
*
* 防止xss跨脚本攻击（替换，根据实际情况调整）
*/
public static String stripXSSAndSql(String value) {
if (value != null) {
// NOTE: It's highly recommended to use the ESAPI library and
// uncomment the following line to
// avoid encoded attacks.
// value = ESAPI.encoder().canonicalize(value);
// Avoid null characters
/** value = value.replaceAll("", ""); ***/
// Avoid anything between script tags
Pattern scriptPattern = Pattern.compile(
"<[\r\n| | ]*script[\r\n| | ]*>(.*?)</[\r\n| | ]*script[\r\n| | ]*>", Pattern.CASE_INSENSITIVE);
value = scriptPattern.matcher(value).replaceAll("");
// Avoid anything in a
// src="http://www.yihaomen.com/article/java/..." type of
// e-xpression
scriptPattern = Pattern.compile("src[\r\n| | ]*=[\r\n| | ]*[\\\"|\\\'](.*?)[\\\"|\\\']",
Pattern.CASE_INSENSITIVE | Pattern.MULTILINE | Pattern.DOTALL);
value = scriptPattern.matcher(value).replaceAll("");
// Remove any lonesome </script> tag
scriptPattern = Pattern.compile("</[\r\n| | ]*script[\r\n| | ]*>", Pattern.CASE_INSENSITIVE);
value = scriptPattern.matcher(value).replaceAll("");
// Remove any lonesome <script ...> tag
scriptPattern = Pattern.compile("<[\r\n| | ]*script(.*?)>",
Pattern.CASE_INSENSITIVE | Pattern.MULTILINE | Pattern.DOTALL);
value = scriptPattern.matcher(value).replaceAll("");
// Avoid eval(...) expressions
scriptPattern = Pattern.compile("eval\\((.*?)\\)",
Pattern.CASE_INSENSITIVE | Pattern.MULTILINE | Pattern.DOTALL);
value = scriptPattern.matcher(value).replaceAll("");
// Avoid e-xpression(...) expressions
scriptPattern = Pattern.compile("e-xpression\\((.*?)\\)",
Pattern.CASE_INSENSITIVE | Pattern.MULTILINE | Pattern.DOTALL);
value = scriptPattern.matcher(value).replaceAll("");
// Avoid javascript:... expressions
scriptPattern = Pattern.compile("javascript[\r\n| | ]*:[\r\n| | ]*", Pattern.CASE_INSENSITIVE);
value = scriptPattern.matcher(value).replaceAll("");
// Avoid vbscript:... expressions
scriptPattern = Pattern.compile("vbscript[\r\n| | ]*:[\r\n| | ]*", Pattern.CASE_INSENSITIVE);
value = scriptPattern.matcher(value).replaceAll("");
// Avoid onload= expressions
scriptPattern = Pattern.compile("onload(.*?)=",
Pattern.CASE_INSENSITIVE | Pattern.MULTILINE | Pattern.DOTALL);
value = scriptPattern.matcher(value).replaceAll("");
}
return value;
}
}
<filter>
<filter-name>XssFilter</filter-name>
<filter-class>com.zemso.filter.XSSFilter</filter-class>
</filter>
<filter-mapping>
<filter-name>XssFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
