Spring防止Xss配置

java

浏览数:482

2019-1-8

web.xml配置

<!-- xss过滤器 -->
    <filter>
        <filter-name>XssFilter</filter-name>
        <filter-class>com.zyyt.sipctask.common.filter.XssFilter</filter-class>
    </filter>
    <filter-mapping>
        <filter-name>XssFilter</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>

XssFilter.java

package com.zyyt.sipctask.common.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 {  
  
    FilterConfig filterConfig = null;  
  
    public void init(FilterConfig filterConfig) throws ServletException {  
        this.filterConfig = filterConfig;  
    }  
  
    public void destroy() {  
        this.filterConfig = null;  
    }  
  
    public void doFilter(ServletRequest request, ServletResponse response,  
            FilterChain chain) throws IOException, ServletException {
        chain.doFilter(new XssHttpServletRequestWrapperNew(  
                    (HttpServletRequest) request), response);  
    }  
}  

XssHttpServletRequestWrapperNew.java


package com.zyyt.sipctask.common.filter;

import java.text.CharacterIterator;
import java.text.StringCharacterIterator;
import java.util.regex.Pattern;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;

public class XssHttpServletRequestWrapperNew extends HttpServletRequestWrapper {
    HttpServletRequest orgRequest = null;

    public XssHttpServletRequestWrapperNew(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);
            value = HTMLEncode(value);
        }
        return value;
    }

    /**
     * spring是使用的getParameterValues方法
     */
    @Override
    public String[] getParameterValues(String name) {
        String[] value = super.getParameterValues(name);
        if (value == null) {
            return null;
        }
        for (int i = 0;i < value.length;i++) {
            value[i] = xssEncode(value[i]);
            value[i] = HTMLEncode(value[i]);
        }
        return value;
    }

    /**
     * 对一些特殊字符进行转义
     * 
     * 
     */
    public static String HTMLEncode(String aText) {
        final StringBuilder result = new StringBuilder();
        final StringCharacterIterator iterator = new StringCharacterIterator(aText);
        char character = iterator.current();
        while (character != CharacterIterator.DONE) {
            if (character == '<') {
                result.append("<");
            } else if (character == '>') {
                result.append(">");
            } else if (character == '\"') {
                result.append("`");
            } else {
                // the char is not a special one
                // add it to the result as is
                result.append(character);
            }
            character = iterator.next();
        }
        return result.toString();
    }

    /**
     * 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
     * 目前xssProject对注入代码要求是必须开始标签和结束标签(如<script></script>)正确匹配才能解析,否则报错;因此只能替换调xssProject换为自定义实现
     * 
     * @param s
     * @return
     */
    private static String xssEncode(String s) {
        //
        // if (s == null || s.isEmpty()) {
        // return s;
        // }
        //
        // StringReader reader = new StringReader(s);
        // StringWriter writer = new StringWriter();
        // try {
        // HTMLParser.process(reader, writer, new XSSFilter(), true);
        //
        // String result = writer.toString();
        //
        // System.out.println("xssEncode-------------------------" + s + " = "
        // + result);
        //
        // return result;
        // } catch (NullPointerException e) {
        // return s;
        // } catch (Exception ex) {
        // ex.printStackTrace();
        // }
        //
        // return null;
        if (s == null || s.isEmpty()) {
            return s;
        }

        String result = stripXSS(s);
        if (null != result) {
            result = escape(result);
        }

        return result;

    }

    public static String escape(String 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('>');// 全角大于号
                break;
            case '<':
                sb.append('<');// 全角小于号
                break;
            case '\'':
                sb.append('‘');// 全角单引号
                break;
            case '\"':
                sb.append('“');// 全角双引号
                break;
            case '\\':
                sb.append('\');// 全角斜线
                break;
            case '%':
                sb.append('%'); // 全角冒号
                break;
            default:
                sb.append(c);
                break;
            }

        }
        return sb.toString();
    }

    private static String stripXSS(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("<script>(.*?)</script>", Pattern.CASE_INSENSITIVE);
            value = scriptPattern.matcher(value).replaceAll("");
            // Avoid anything in a src='...' type of expression
            scriptPattern = Pattern.compile("src[\r\n]*=[\r\n]*\\\'(.*?)\\\'",
                    Pattern.CASE_INSENSITIVE | Pattern.MULTILINE | Pattern.DOTALL);
            value = scriptPattern.matcher(value).replaceAll("");
            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("</script>", Pattern.CASE_INSENSITIVE);
            value = scriptPattern.matcher(value).replaceAll("");
            // Remove any lonesome <script ...> tag
            scriptPattern = Pattern.compile("<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 expression(...) expressions
            scriptPattern = Pattern.compile("expression\\((.*?)\\)",
                    Pattern.CASE_INSENSITIVE | Pattern.MULTILINE | Pattern.DOTALL);
            value = scriptPattern.matcher(value).replaceAll("");
            // Avoid javascript:... expressions
            scriptPattern = Pattern.compile("javascript:", Pattern.CASE_INSENSITIVE);
            value = scriptPattern.matcher(value).replaceAll("");
            value = scriptPattern.matcher(value).replaceAll("");
            // Avoid onload= expressions
            scriptPattern = Pattern.compile("onload(.*?)=",
                    Pattern.CASE_INSENSITIVE | Pattern.MULTILINE | Pattern.DOTALL);
            value = scriptPattern.matcher(value).replaceAll("");

            scriptPattern = Pattern.compile("<iframe>(.*?)</iframe>", Pattern.CASE_INSENSITIVE);
            value = scriptPattern.matcher(value).replaceAll("");

            scriptPattern = Pattern.compile("</iframe>", Pattern.CASE_INSENSITIVE);
            value = scriptPattern.matcher(value).replaceAll("");
            // Remove any lonesome <script ...> tag
            scriptPattern = Pattern.compile("<iframe(.*?)>",
                    Pattern.CASE_INSENSITIVE | Pattern.MULTILINE | Pattern.DOTALL);
            value = scriptPattern.matcher(value).replaceAll("");
        }
        return value;
    }

    /**
     * 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 XssHttpServletRequestWrapperNew) {
            return ((XssHttpServletRequestWrapperNew) req).getOrgRequest();
        }

        return req;
    }

}