SQL盲注、SQL注入 - SpringBoot配置SQL注入过滤器

1. SQL盲注、SQL注入

  风险：可能会查看、修改或删除数据库条目和表。

  原因：未对用户输入正确执行危险字符清理。

  固定值：查看危险字符注入的可能解决方案。

2. pom.xml添加依赖

<dependency>
	<groupId>org.springframework.boot</groupId>
	<artifactId>spring-boot-configuration-processor</artifactId>
	<optional>true</optional>
</dependency>

3. 添加SQL注入包装类

import java.util.regex.Matcher;
import java.util.regex.Pattern;

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

import lombok.extern.slf4j.Slf4j;

/**
 * SQL注入包装类
 *
 * @author CL
 *
 */
@Slf4j
public class SqlInjectHttpServletRequestWrapper extends HttpServletRequestWrapper {

	/**
	 * 构造请求对象
	 *
	 * @param request
	 */
	public SqlInjectHttpServletRequestWrapper(HttpServletRequest request) {
		super(request);
	}

	/**
	 * 获取头部参数
	 *
	 * @param v 参数值
	 */
	@Override
	public String getHeader(String v) {
		String header = super.getHeader(v);
		if (header == null || "".equals(header)) {
			return header;
		}
		return sqlFilter(header);
	}

	/**
	 * 获取参数
	 *
	 * @param v 参数值
	 */
	@Override
	public String getParameter(String v) {
		String param = super.getParameter(v);
		if (param == null || "".equals(param)) {
			return param;
		}
		return sqlFilter(param);
	}

	/**
	 * 获取参数值
	 *
	 * @param v 参数值
	 */
	@Override
	public String[] getParameterValues(String v) {
		String[] values = super.getParameterValues(v);
		if (values == null) {
			return values;
		}

		// 富文本内容不过滤
		if ("remarks".equals(v)) {
			return values;
		}

		int length = values.length;
		String[] resultValues = new String[length];
		for (int i = 0; i < length; i++) {
			// 过滤特殊字符
			resultValues[i] = sqlFilter(values[i]);
			if (!(resultValues[i]).equals(values[i])) {
				log.debug("SQL注入过滤器 => 过滤前：{} => 过滤后：{}", values[i], resultValues[i]);
			}
		}
		return resultValues;
	}

	/**
	 * 预编译SQL过滤正则表达式
	 */
	private Pattern sqlPattern = Pattern.compile(
			"(?:')|(?:--)|(/\\*(?:.|[\\n\\r])*?\\*/)|(\\b(select|update|and|or|delete|insert|trancate|char|into|substr|ascii|declare|exec|count|master|into|drop|execute)\\b)",
			Pattern.CASE_INSENSITIVE);

	/**
	 * SQL过滤
	 *
	 * @param v 参数值
	 * @return
	 */
	private String sqlFilter(String v) {
		if (v != null) {
			String resultVal = v;
			Matcher matcher = sqlPattern.matcher(resultVal);
			if (matcher.find()) {
				resultVal = matcher.replaceAll("");
			}
			if (!resultVal.equals(v)) {
				return "";
			}
			return resultVal;
		}
		return null;
	}
}

4. 配置文件添加配置

# 信息安全
security:
  sql:
    enable: true
    excludes:
      - /images/*
      - /jquery/*
      - /layui/*

5. 添加SQL注入过滤器

import java.io.IOException;
import java.util.List;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

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.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;

import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.stereotype.Component;

/**
 * SQL注入过滤器
 *
 * @author CL
 *
 */
@Component
@ConfigurationProperties(prefix = "security.sql")
@WebFilter(filterName = "SqlInjectFilter", urlPatterns = "/*")
public class SqlInjectFilter implements Filter {

	/**
	 * 过滤器配置对象
	 */
	FilterConfig filterConfig = null;

	/**
	 * 是否启用
	 */
	private boolean enable;

	public void setEnable(boolean enable) {
		this.enable = enable;
	}

	/**
	 * 忽略的URL
	 */
	private List<String> excludes;

	public void setExcludes(List<String> excludes) {
		this.excludes = excludes;
	}

	/**
	 * 初始化
	 */
	@Override
	public void init(FilterConfig filterConfig) throws ServletException {
		this.filterConfig = filterConfig;
	}

	/**
	 * 拦截
	 */
	@Override
	public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain)
			throws IOException, ServletException {
		HttpServletRequest request = (HttpServletRequest) servletRequest;

		// 不启用或者已忽略的URL不拦截
		if (!enable || isExcludeUrl(request.getServletPath())) {
			filterChain.doFilter(servletRequest, servletResponse);
			return;
		}
		SqlInjectHttpServletRequestWrapper sqlInjectHttpServletRequestWrapper = new SqlInjectHttpServletRequestWrapper(
				request);
		filterChain.doFilter(sqlInjectHttpServletRequestWrapper, servletResponse);
	}

	/**
	 * 销毁
	 */
	@Override
	public void destroy() {
		this.filterConfig = null;
	}

	/**
	 * 判断是否为忽略的URL
	 *
	 * @param urlPath URL路径
	 * @return true-忽略，false-过滤
	 */
	private boolean isExcludeUrl(String url) {
		if (excludes == null || excludes.isEmpty()) {
			return false;
		}
		return excludes.stream().map(pattern -> Pattern.compile("^" + pattern)).map(p -> p.matcher(url))
				.anyMatch(Matcher::find);
	}
}