SpringMVC防止XSS注入

xss（Cross Site Scripting）注入就是，跨站脚本攻击，和sql注入类似的，在请求中添加恶意脚本，实现控制用户。

XssHttpServletRequestWrappe.java

重写XssHttpServletRequestWrapper中的方法：

package com.henu.util;

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

/**
 * XSS
 *
 * @author duxiangyu
 *
 */
public class XssHttpServletRequestWrapper extends HttpServletRequestWrapper {
    public XssHttpServletRequestWrapper(HttpServletRequest servletRequest) {
        super(servletRequest);
    }

    public String[] getParameterValues(String parameter) {
        String[] values = super.getParameterValues(parameter);
        if (values == null)
            return null;
        int count = values.length;
        String[] encodedValues = new String[count];
        for (int i = 0; i < count; i++) {
            encodedValues[i] = cleanXSS(values[i]);
        }
        return encodedValues;
    }

    public String getParameter(String parameter) {
        String value = super.getParameter(parameter);
        if (value == null)
            return null;
        return cleanXSS(value);
    }

    public String getHeader(String name) {
        String value = super.getHeader(name);
        if (value == null)
            return null;
        return cleanXSS(value);
    }

    // 这里可以自己实现转义，也可以直接用工具类进行转义，比如说org.apache.common.lang.StringEscapeUtils和org.springframework.web.util.HtmlUtils
    private String cleanXSS(String str) {
        StringBuffer sb = new StringBuffer();
        for (int i = 0; i < str.length(); i++) {
            char c = str.charAt(i);

            switch (c) {
            case '\n':
                sb.append(c);
                break;
            case '<':
                sb.append("&lt;");
                break;
            case '>':
                sb.append("&gt;");
                break;
            case '&':
                sb.append("&amp;");
                break;
            case '\'':
                sb.append("&apos;");
                break;
            case '"':
                sb.append("&quot;");
                break;
            default:
                if ((c < ' ') || (c > '~')) {
                    sb.append("&#x");
                    sb.append(Integer.toString(c, 16));
                    sb.append(';');
                } else {
                    sb.append(c);
                }
                break;
            }
        }
        return sb.toString();
    }
}

XssFilter.java

写个拦截器，对请求进行拦截过滤：

package com.henu.util;

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;

/**
 * XSS 过滤器
 *
 * @author duxiangyu
 *
 */
public class XssFilter implements Filter {
    FilterConfig filterConfig = null;

    public void init(FilterConfig filterConfig) throws ServletException {
        this.filterConfig = filterConfig;
    }

    public void destroy() {
        this.filterConfig = null;
    }

    // 对request进行包装
    public void doFilter(ServletRequest request, ServletResponse response,
            FilterChain chain) throws IOException, ServletException {
        chain.doFilter(new XssHttpServletRequestWrapper(
                (HttpServletRequest) request), response);
    }
}

在web.xml中配置拦截器，对所有的.ht请求进行过滤：

<filter>
    <filter-name>xssFilter</filter-name>
    <filter-class>com.henu.util.XssFilter</filter-class>
</filter>
<filter-mapping>
    <filter-name>xssFilter</filter-name>
    <url-pattern>*.ht</url-pattern>
    <dispatcher>REQUEST</dispatcher>
</filter-mapping>