文章摘要:xss跨站脚本攻击如何修复 如何防止xss跨站脚本攻击
xss跨站脚本攻击的解决方案: 1.建立一个HttpServletRequestWapper的包装类,对用户发 […]
xss跨站脚本攻击的解决方案:
1.建立一个HttpServletRequestWapper的包装类,对用户发送的请求进行包装,把request中包含XSS代码进行过滤,代码如下:
import java.util.Map;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;
public class XssHttpServletRequestWrapper extends HttpServletRequestWrapper {
HttpServletRequest orgRequest = null;
public XssHttpServletRequestWrapper(HttpServletRequest request) {
super(request);
}
/**
* 覆盖getParameter方法,将参数名和参数值都做xss过滤。
* 如果需要获得原始的值,则通过super.getParameterValues(name)来获取
* getParameterNames,getParameterValues和getParameterMap也可能需要覆盖
*/
@Override
public String getParameter(String name) {
String value = super.getParameter(xssEncode(name));
if (value != null) {
value = xssEncode(value);
}
return value;
}
@Override
public String[] getParameterValues(String name) {
String[] value = super.getParameterValues(name);
if(value != null){
for (int i = 0; i < value.length; i++) {
value[i] = xssEncode(value[i]);
}
}
return value;
}
@Override
public Map getParameterMap() {
// TODO Auto-generated method stub
return super.getParameterMap();
}
/**
* 覆盖getHeader方法,将参数名和参数值都做xss过滤。
* 如果需要获得原始的值,则通过super.getHeaders(name)来获取
* getHeaderNames 也可能需要覆盖
* 这一段代码在一开始没有注释掉导致出现406错误,原因是406错误是HTTP协议状态码的一种,
* 表示无法使用请求的内容特性来响应请求的网页。一般是指客户端浏览器不接受所请求页面的 MIME 类型。
*
@Override
public String getHeader(String name) {
String value = super.getHeader(xssEncode(name));
if (value != null) {
value = xssEncode(value);
}
return value;
}
**/
/**
* 将容易引起xss漏洞的半角字符直接替换成全角字符 在保证不删除数据的情况下保存
* @param s
* @return 过滤后的值
*/
private static String xssEncode(String value) {
if (value == null || value.isEmpty()) {
return value;
}
value = value.replaceAll("eval\((.*)\)", "");
value = value.replaceAll("[\"\'][\s]*javascript:(.*)[\"\']", """");
value = value.replaceAll("(?i)<script.*?>.*?<script.*?>", "");
value = value.replaceAll("(?i)<script.*?>.*?</script.*?>", "");
value = value.replaceAll("(?i)<.*?javascript:.*?>.*?</.*?>", "");
value = value.replaceAll("(?i)<.*?\s+on.*?>.*?</.*?>", "");
return value;
}
}
2.使用Filter过滤器实现对Request的过滤,代码如下:
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;
import com.lyms.wxyl.base.wrapper.XssHttpServletRequestWrapper;
public class XssFilter implements Filter {
public void destroy() {
// TODO Auto-generated method stub
}
/**
* 过滤器用来过滤的方法
*/
public void doFilter(ServletRequest request, ServletResponse response,FilterChain chain) throws IOException, ServletException {
//包装request
XssHttpServletRequestWrapper xssRequest = new XssHttpServletRequestWrapper((HttpServletRequest) request);
chain.doFilter(xssRequest, response);
}
public void init(FilterConfig filterConfig) throws ServletException {
// TODO Auto-generated method stub
}
}
3.在Web.xml中定义好Filter,例如:
<filter>
<filter-name>XssFilter</filter-name>
<filter-class>包名.XssFilter</filter-class>
</filter>
<filter-mapping>
<filter-name>XssFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
4.Filter类需要引入javax.servlet.api的jar包,因此要在pom.xml配置jar包,代码:
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>servlet-api</artifactId>
<version>${servlet.version}</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>jsp-api</artifactId>
<version>2.0</version>
<scope>provided</scope>
</dependency>
<properties>
<servlet.version>3.0-alpha-1</servlet.version>
</properties>