XSS漏洞解决方案之一 过滤器

               

XSS漏洞解决方案之一：过滤器

一：web.xml文件 

          xssFilter       com.baidu.rigel.sandbox.core.filter.XSSFilter                    xssFilter      /*              xssFilter     com.baidu.rigel.sandbox.core.filter.XSSFilter          xssFilter    /*  

 

    二：过滤器:XSSFilter.java   

package com.rigel.sandbox.core.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;    import com.rigel.sandbox.core.util.XssHttpServletRequestWrapper;    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 {            XssHttpServletRequestWrapper xssRequest = new XssHttpServletRequestWrapper(                  (HttpServletRequest) request);          chain.doFilter(xssRequest, response);      }        @Override      public void destroy() {      }    }  package com.rigel.sandbox.core.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;import com.rigel.sandbox.core.util.XssHttpServletRequestWrapper;public class XSSFilter implements Filter {@Overridepublic void init(FilterConfig filterConfig) throws ServletException {}@Overridepublic void doFilter(ServletRequest request, ServletResponse response,FilterChain chain) throws IOException, ServletException {XssHttpServletRequestWrapper xssRequest = new XssHttpServletRequestWrapper((HttpServletRequest) request);chain.doFilter(xssRequest, response);}@Overridepublic void destroy() {}}

 

       三：包装器：XssHttpServletRequestWrapper.java 

package com.rigel.sandbox.core.util;    import javax.servlet.http.HttpServletRequest;  import javax.servlet.http.HttpServletRequestWrapper;    public class XssHttpServletRequestWrapper extends HttpServletRequestWrapper {      HttpServletRequest orgRequest = null;        public XssHttpServletRequestWrapper(HttpServletRequest request) {          super(request);          orgRequest = 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;      }        /**      * 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      */      @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      *       * @param s      * @return      */      private static String xssEncode(String s) {          if (s == null || s.isEmpty()) {              return 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;              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 XssHttpServletRequestWrapper) {              return ((XssHttpServletRequestWrapper) req).getOrgRequest();          }            return req;      }  }