Springboot实现XSS漏洞过滤

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背景

前阵子做了几个项目，终于开发完毕，进入了测试阶段，信心满满将项目部署到测试环境，然后做了安全测评之后.....

                 ​(什么！你竟然说我代码不安全？？？)

然后测出了Xss漏洞安全的问题

解决方案

场景：可以在页面输入框输入JS脚本，攻击者可以利用此漏洞执行恶意的代码！

问题演示

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所以我们要对于前端传输的参数做处理，做统一全局过滤处理

既然要过滤处理，我们首先需要实现一个自定义过滤器

总共包含以下四部分

XssUtil

XssFilterAutoConfig

XssHttpServletRequestWrapper

XssStringfJsonDeserializer

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最后我们需要在全局过滤器中使用我们实现的Xss自定义过滤器

代码实现

• XssFilterAtuoConfig实现代码

 import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.module.SimpleModule;
import net.greatsoft.overallbudget.filter.SimpleCORSFilter;
import org.springframework.boot.context.embedded.FilterRegistrationBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Primary;
import org.springframework.http.converter.json.Jackson2ObjectMapperBuilder;
import org.springframework.http.converter.json.MappingJackson2HttpMessageConverter;

/**
 * Created by wjy on 2020/11/5.
 * xss 自动配置类
 */
@Configuration
public class XssFilterAtuoConfig {

    /**
     * 注册自定义过滤器
     * @return
     */
    @Bean
    public FilterRegistrationBean xssFiltrRegister() {
        FilterRegistrationBean registration = new FilterRegistrationBean();
        //设置系统过滤器 (setFilter就是你所定义的过滤器filter类)
        registration.setFilter(new SimpleCORSFilter());
        //过滤所有路径
        registration.addUrlPatterns("/*");
        //过滤器名称
        registration.setName("XssFilter");
        //优先级
        registration.setOrder(1);
        return registration;
    }

    /**
     *    过滤JSON数据
     * @return
     */
    @Bean
    @Primary
    public MappingJackson2HttpMessageConverter mappingJackson2HttpMessageConverter() {
        SimpleModule module = new SimpleModule();
        //自定义序列化过滤配置(XssStringJsonDeserializer), 对入参进行转译
        module.addDeserializer(String.class, new XssStringJsonDeserializer());
        // 注册解析器
        ObjectMapper objectMapper = Jackson2ObjectMapperBuilder.json().build();
        objectMapper.registerModule(module);
        return new MappingJackson2HttpMessageConverter(objectMapper);
    }
}

• XssHttpServletRequestWrapper实现代码

/**
 * Created by wjy on 2020/11/5.
 * xss 包装
 */
public class XssHttpServletRequestWrapper extends HttpServletRequestWrapper {

    public XssHttpServletRequestWrapper(HttpServletRequest request) {
        super(request);
    }

    /**
     * 对header处理
     * @param name
     * @return
     */
    @Override
    public String getHeader(String name) {
        String value = super.getHeader(name);
        return XssUtil.cleanXSS(value);
    }

    /**
     * 对参数处理
     * @param name
     * @return
     */
    @Override
    public String getParameter(String name) {
        String value = super.getParameter(name);
        return XssUtil.cleanXSS(value);
    }

    /**
     * 对数值进行处理
     * @param name
     * @return
     */
    @Override
    public String[] getParameterValues(String name) {
        String[] values = super.getParameterValues(name);
        if (values != null) {
            int length = values.length;
            String[] escapseValues = new String[length];
            for (int i = 0; i < length; i++) {
                escapseValues[i] = XssUtil.cleanXSS(values[i]);
            }
            return escapseValues;
        }
        return super.getParameterValues(name);
    }

    /**
     * 主要是针对HandlerMapping.URI_TEMPLATE_VARIABLES_ATTRIBUTE 获取pathvalue的时候把原来的pathvalue经过xss过滤掉
     */
    @Override
    public Object getAttribute(String name) {
        // 获取pathvalue的值
        if (HandlerMapping.URI_TEMPLATE_VARIABLES_ATTRIBUTE.equals(name)) {
            Map uriTemplateVars = (Map) super.getAttribute(HandlerMapping.URI_TEMPLATE_VARIABLES_ATTRIBUTE);
            if (Objects.isNull(uriTemplateVars)) {
                return uriTemplateVars;
            }
            Map newMap = new LinkedHashMap<>();
            uriTemplateVars.forEach((key, value) -> {
                if (value instanceof String) {
                    newMap.put(key, XssUtil.cleanXSS((String) value));
                } else {
                    newMap.put(key, value);

                }
            });
            return newMap;
        } else {
            return super.getAttribute(name);
        }
    }
} 

• XssStringJsonDeserializer代码实现

 /**
 * Created by wjy on 2020/11/5.
 * 基于xss的JsonDeserializer
 */
public class XssStringJsonDeserializer extends JsonDeserializer<String> {


    @Override
    public Class<String> handledType() {
        return String.class;
    }

    @Override
    public String deserialize(JsonParser jsonParser, DeserializationContext deserializationContext) throws IOException {
        return XssUtil.cleanXSS(jsonParser.getValueAsString());
    }
} 

• XssUtil代码实现

 /**
 * Created by wjy on 2020/11/5.
 * xss工具类
 */
public class XssUtil {

    public static String cleanXSS(String value) {
        if (Objects.isNull(value)) {
            return value;
        }
        //在这里自定义需要过滤的字符
        value = value.replaceAll("<", "& lt;").replaceAll(">", "& gt;");
        value = value.replaceAll("(", "& #40;").replaceAll(")", "& #41;");
        value = value.replaceAll("'", "& #39;");
        value = value.replaceAll("eval((.*))", "");
        value = value.replaceAll("["'][s]*javascript:(.*)["']", """");
        value = value.replaceAll("<script>", "");
        return value;
    }
} 

全局过滤器实现

 @Component
public class SimpleCORSFilter implements Filter {

    @Override
    public void doFilter(ServletRequest req, ServletResponse res,
            FilterChain chain) throws IOException, ServletException {
        // 在这里，使用我们实现的XSS过滤器
        XssHttpServletRequestWrapper request =
                new XssHttpServletRequestWrapper((HttpServletRequest) req);

        HttpServletResponse response = (HttpServletResponse) res;
        response.setHeader("Access-Control-Allow-Origin", "*");
        response.setHeader("Access-Control-Allow-Methods",
                "POST, GET, PUT, OPTIONS, DELETE");
        response.setHeader("Access-Control-Max-Age", "3600");
        response.setHeader("Access-Control-Allow-Headers",
                "Origin, X-Requested-With, Content-Type, Accept, token");
        
        chain.doFilter(request, response);
        
    }

    public void init(FilterConfig filterConfig) {
    }

    public void destroy() {
    }

} 

好了，以上就是对Xss漏洞的处理

看完如果对你有帮助，看到右下角的 “一键三连” 了吗，没错点它[哈哈]

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