Spring Boot 防止XSS攻击

• XSS

跨站脚本工具（cross 斯特scripting），为不和层叠样式表（cascading style sheets,CSS）的缩写混淆，故将跨站脚本攻击缩写为XSS。恶意攻击者往web页面里插入恶意ScriptScript代码，当用户浏览该页之时，嵌入其中Web里面的Script代码会被执行，从而达到恶意攻击用户的目的。防止XSS攻击简单的预防就是对Request请求中的一些参数去掉一些比较敏感的脚本命令。原本是打算通过SpringMVC的HandlerInterceptor机制来实现的，通过获取request然后对request中的参数进行修改，结果虽然值修改了，但在Controller中获取的数值还是没有修改的。没办法就是要Filter来完成。简单来说就是创建一个新的HttpRequest类XssHttpServletRequestWrapper，然后重写一些get方法（获取参数时对参数进行XSS判断预防）

流程梳理

包装request->创建过滤器->添加过滤器

1. 创建包装request的类 XssHttpServletRequestWrapper

import java.io.BufferedReader;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.nio.charset.Charset;
import java.util.regex.Matcher;
import java.util.regex.Pattern;import javax.servlet.ReadListener;
import javax.servlet.ServletInputStream;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;
import javax.servlet.http.HttpServletResponse;import org.slf4j.Logger;
import org.slf4j.LoggerFactory;import com.sysware.framework.exceptions.SyswareRuntimeException;
import com.sysware.framework.file.service.impl.FileGridServiceImpl;public class XssHttpServletRequestWraper extends HttpServletRequestWrapper {private Logger log = LoggerFactory.getLogger(FileGridServiceImpl.class);public XssHttpServletRequestWraper() {super(null);}public XssHttpServletRequestWraper(HttpServletRequest httpservletrequest) {super(httpservletrequest);}//过滤springmvc中的 @RequestParam 注解中的参数public String[] getParameterValues(String s) {String str[] = super.getParameterValues(s);if (str == null) {return null;}int i = str.length;String as1[] = new String[i];for (int j = 0; j < i; j++) {//System.out.println("getParameterValues:"+str[j]);as1[j] = cleanXSS(cleanSQLInject(str[j]));}log.info("XssHttpServletRequestWraper净化后的请求为：==========" + as1);return as1;}//过滤request.getParameter的参数public String getParameter(String s) {String s1 = super.getParameter(s);if (s1 == null) {return null;} else {String s2 = cleanXSS(cleanSQLInject(s1));log.info("XssHttpServletRequestWraper净化后的请求为：==========" + s2);return s2;}}//过滤请求体 json 格式的@Overridepublic ServletInputStream getInputStream() throws IOException {final ByteArrayInputStream bais = new ByteArrayInputStream(inputHandlers(super.getInputStream ()).getBytes ());return new ServletInputStream() {@Overridepublic int read() throws IOException {return bais.read();}@Overridepublic boolean isFinished() {return false;}@Overridepublic boolean isReady() {return false;}@Overridepublic void setReadListener(ReadListener readListener) { }};}public   String inputHandlers(ServletInputStream servletInputStream){StringBuilder sb = new StringBuilder();BufferedReader reader = null;try {reader = new BufferedReader(new InputStreamReader(servletInputStream, Charset.forName("UTF-8")));String line = "";while ((line = reader.readLine()) != null) {sb.append(line);}} catch (IOException e) {e.printStackTrace();} finally {if (servletInputStream != null) {try {servletInputStream.close();} catch (IOException e) {e.printStackTrace();}}if (reader != null) {try {reader.close();} catch (IOException e) {e.printStackTrace();}}}return  cleanXSS(sb.toString ());}public String cleanXSS(String src) {String temp = src;src = src.replaceAll("<", "＜").replaceAll(">", "＞");src = src.replaceAll("\\(", "（").replaceAll("\\)", "）");src = src.replaceAll("'", "");src = src.replaceAll(";", "");/**-----------------------start--------------------------*/src = src.replaceAll("<", "& lt;").replaceAll(">", "& gt;");src = src.replaceAll("\\(", "& #40;").replaceAll("\\)", "& #41");src = src.replaceAll("eval\\((.*)\\)", "");src = src.replaceAll("[\\\"\\\'][\\s]*javascript:(.*)[\\\"\\\']", "\"\"");
//        src = src.replaceAll("script", "");
//        src = src.replaceAll("link", "");
//        src = src.replaceAll("frame", "");/**-----------------------end--------------------------*/Pattern pattern = Pattern.compile("(eval\\((.*)\\)|script)",Pattern.CASE_INSENSITIVE);Matcher matcher = pattern.matcher(src);src = matcher.replaceAll("");pattern = Pattern.compile("[\\\"\\'][\\s]*javascript:(.*)[\\\"\\']",Pattern.CASE_INSENSITIVE);matcher = pattern.matcher(src);src = matcher.replaceAll("\"\"");// 增加脚本src = src.replaceAll("script", "").replaceAll(";", "")/*.replaceAll("\"", "").replaceAll("@", "")*/.replaceAll("0x0d", "").replaceAll("0x0a", "");//        if (!temp.equals(src)) {
//            // System.out.println("输入信息存在xss攻击！");
//            // System.out.println("原始输入信息-->" + temp);
//            // System.out.println("处理后信息-->" + src);
// 
//            log.error("xss攻击检查：参数含有非法攻击字符，已禁止继续访问！！");
//            log.error("原始输入信息-->" + temp);
// 
//            throw new SyswareRuntimeException("xss攻击检查：参数含有非法攻击字符，已禁止继续访问！！");
//        }return src;}//输出public void outputMsgByOutputStream(HttpServletResponse response, String msg) throws IOException {ServletOutputStream outputStream = response.getOutputStream(); //获取输出流response.setHeader("content-type", "text/html;charset=UTF-8"); //通过设置响应头控制浏览器以UTF-8的编码显示数据，如果不加这句话，那么浏览器显示的将是乱码byte[] dataByteArr = msg.getBytes("UTF-8");// 将字符转换成字节数组，指定以UTF-8编码进行转换outputStream.write(dataByteArr);// 使用OutputStream流向客户端输出字节数组}// 需要增加通配，过滤大小写组合public String cleanSQLInject(String src) {String lowSrc = src.toLowerCase();String temp = src;String lowSrcAfter = lowSrc.replaceAll(" insert ", "forbidI").replaceAll(" select ", "forbidS").replaceAll(" update ", "forbidU").replaceAll(" delete ", "forbidD").replaceAll(" and ", "forbidA").replaceAll(" or ", "forbidO").replace("'", "");if (!lowSrcAfter.equals(lowSrc)) {log.error("sql注入检查：输入信息存在SQL攻击！");log.error("原始输入信息-->" + temp);log.error("处理后信息-->" + lowSrc);throw new SyswareRuntimeException("sql注入检查：参数含有非法攻击字符，已禁止继续访问！！");}return src;}}

注意：
getInputStream()方法的流处理，注解方式获取数据貌似是根据这个流取得的数据。
因为super.getInputStream()流只允许读取一次，所以在getInputStream()方法中
处理完流数据后返回了一个新的ServletInputStream。另外替换方法里的替换规则，
也可以根据实际业务需要进行调整。

2.创建过滤器 XssFilter

@Component
public class XssFilter implements Filter {// 忽略权限检查的url地址private final String[] excludeUrls = new String[]{"/api/item","api/document"};public void doFilter(ServletRequest arg0, ServletResponse arg1, FilterChain arg2)throws IOException, ServletException {HttpServletRequest req = (HttpServletRequest) arg0;HttpServletResponse response = (HttpServletResponse) arg1;String pathInfo = req.getPathInfo() == null ? "" : req.getPathInfo();//获取请求url的后两层String url = req.getServletPath() + pathInfo;//获取请求你ip后的全部路径String uri = req.getRequestURI();//注入xss过滤器实例XssHttpServletRequestWraper reqW = new XssHttpServletRequestWraper(req);//过滤掉不需要的Xss校验的地址for (String str : excludeUrls) {if (uri.indexOf(str) >= 0) {//过滤arg2.doFilter(reqW, response);return;}}arg2.doFilter(arg0, response);}public void destroy() {}public void init(FilterConfig filterconfig1) throws ServletException {}
}