1、XSS跨站脚本攻击
①：XSS漏洞介绍
跨站脚本攻击XSS是指攻击者往Web页面里插入恶意Script代码，当用户浏览该页之时，嵌入其中Web里面的Script代码会被解析执行，从而达到恶意攻击用户的目的。
XSS攻击针对的是用户层面的攻击！
②：XSS漏洞分类
存储型XSS：存储型XSS，持久化，代码是存储在服务器中的，如在个人信息或发表文章等地方，插入代码，如果没有过滤或过滤不严，那么这些代码将储存到服务器中，用户访问该页面的时候触发代码执行。
这种XSS比较危险，容易造成蠕虫，盗窃cookie
反射型XSS：非持久化，需要欺骗用户自己去点击链接才能触发XSS代码（服务器中没有这样的页面和内容），一般容易出现在搜索页面
③：防护建议
限制用户输入，表单数据规定值得类型，例如年龄只能是int，name为字母数字组合
- 对数据进行html encode处理
- 过滤或移除特殊的html标签
- 过滤javascript事件的标签
2、 SQL注入攻击
①：SQL注入漏洞介绍
SQL注入（SQLi）是一种注入攻击，可以执行恶意SQL语句。它通过将任意SQL代码插入数据库查询，使攻击者能够完全控制Web应用程序后面的数据库服务器。攻击者可以使用SQL注入漏洞绕过应用程序安全措施；可以绕过网页或Web应用程序的身份验证和授权，并检索整个SQL数据库的内容；还可以使用SQL注入来添加，修改和删除数据库中的记录。
SQL注入漏洞可能会影响使用SQL数据库（如MySQL，Oracle，SQL Server或其他）的任何网站或Web应用程序。犯罪分子可能会利用它来未经授权访问用户的敏感数据：客户信息，个人数据，商业机密，知识产权等。SQL注入攻击是最古老，最流行，最危险的Web应用程序漏洞之一
②：防护建议
使用mybatis中#{}可以有效防止sql注入
- 使用#{}时
<select id="getBlogById" resultType="Blog" parameterType=”int”>
select id,title,author,content
from blog where id=#{id}
</select>
打印出执行的sql语句，会看到sql是这样的：
select id,title,author,content from blog where id = ?
不管输入什么参数，打印出的sql都是这样的。
这是因为mybatis启用了预编译功能，在sql执行前，会先将上面的sql发送给数据库进行编译，执行时，直接使用编译好的sql，替换占位符“？”就可以了。
因为sql注入只能对编译过程起作用，所以像#{}这样预编译成？的方式就很好地避免了sql注入的问题
mybatis是如何做到sql预编译的呢？
其实在框架底层，是jdbc中的PreparedStatement类在起作用，PreparedStatement是我们很熟悉的Statement的子类，它的对象包含了编译好的sql语句。
这种“准备好”的方式不仅能提高安全性，而且在多次执行一个sql时，能够提高效率，原因是sql已编译好，再次执行时无需再编译
- 使用${}时
<select id="orderBlog" resultType="Blog" parameterType=”map”> select id,title,author,content from blog order by ${<!-- -->orderParam}</select>仔细观察，内联参数的格式由“#{<!-- -->xxx}”变为了${<!-- -->xxx}。如果我们给参数“orderParam”赋值为”id”,将sql打印出来，是这样的：select id,title,author,contet from blog order by id<select id="orderBlog" resultType="Blog" parameterType=”map”>
select id,title,author,content
from blog order by ${orderParam}
</select>仔细观察，内联参数的格式由“#{xxx}”变为了${xxx}。如果我们给参数“orderParam”赋值为”id”,将sql打印出来，是这样的：
select id,title,author,contet from blog order by id
显然，这样是无法阻止sql注入的，参数会直接参与sql编译，从而不能避免注入攻击。但涉及到动态表名和列名时，只能使用“${}”这样的参数格式，所以，这样的参数需要我们在代码中手工进行处理来防止注入
3、 SpringBoot中如何防止XSS攻击和sql注入
对于Xss攻击和Sql注入，我们可以通过过滤器来搞定，可根据业务需要排除部分请求
①：创建Xss请求过滤类
XssAndSqlHttpServletRequestWrapper
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.util.StreamUtils;
import javax.servlet.ReadListener;
import javax.servlet.ServletInputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;
import java.io.BufferedReader;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.*;
import java.util.regex.Pattern;
/**
* @author code
* @version 1.0
* @Date 2023/2/7 10:38
* @Description ${DESCRIPTION}
*/
public class XssAndSqlHttpServletRequestWrapper extends HttpServletRequestWrapper {
private final Logger logger = LoggerFactory.getLogger(XssAndSqlHttpServletRequestWrapper.class);
private String key = "and|exec|insert|select|delete|update|count|*|%|chr|mid|master|truncate|char|declare|;|or|-|+";
private Set<String> notAllowedKeyWords = new HashSet<String>(0);
HttpServletRequest orgRequest = null;
private Map<String, String[]> parameterMap;
private final byte[] body; //用于保存读取body中数据
public XssAndSqlHttpServletRequestWrapper(HttpServletRequest request) throws IOException {
super(request);
orgRequest = request;
parameterMap = request.getParameterMap();
body = StreamUtils.copyToByteArray(request.getInputStream());
String keyStr[] = key.split("\\|");
for (String str : keyStr) {
notAllowedKeyWords.add(str);
}
}
// 重写几个HttpServletRequestWrapper中的方法
/**
* 获取所有参数名
*
* @return 返回所有参数名
*/
@Override
public Enumeration<String> getParameterNames() {
Vector<String> vector = new Vector<String>(parameterMap.keySet());
return vector.elements();
}
/**
* 覆盖getParameter方法，将参数名和参数值都做xss & sql过滤。<br>
* 如果需要获得原始的值，则通过super.getParameterValues(name)来获取<br>
* getParameterNames,getParameterValues和getParameterMap也可能需要覆盖
*/
@Override
public String getParameter(String name) {
String[] results = parameterMap.get(name);
if (results == null || results.length == 0)
return null;
else {
String value = results[0];
if (value != null) {
value = xssEncode(value);
}
return value;
}
}
@Override
public Map<String, String[]> getParameterMap() {
Map<String,String[]> values = super.getParameterMap();
if(null == values){
return null;
}
Map<String,String[]> result = new HashMap<>();
for (String key : values.keySet()) {
String encodedKey = xssEncode(key);
int count = values.get(key).length;
String[] encodedValues = new String[count];
for(int i = 0;i < count;i++){
encodedValues[i] = xssEncode(values.get(key)[i]);
}
result.put(encodedKey,encodedValues);
}
return result;
}
/**
* 获取指定参数名的所有值的数组，如：checkbox的所有数据 接收数组变量 ，如checkobx类型
*/
@Override
public String[] getParameterValues(String name) {
String[] results = parameterMap.get(name);
if (results == null || results.length == 0)
return null;
else {
int length = results.length;
for (int i = 0; i < length; i++) {
results[i] = xssEncode(results[i]);
}
return results;
}
}
/**
* 覆盖getHeader方法，将参数名和参数值都做xss & sql过滤。<br>
* 如果需要获得原始的值，则通过super.getHeaders(name)来获取<br>
* 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 & sql漏洞的半角字符直接替换成全角字符
*
* @param s
* @return
*/
private String xssEncode(String s) {
if (s == null || s.isEmpty()) {
return s;
} else {
s = stripXSSAndSql(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;
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
*/
@SuppressWarnings("unused")
public HttpServletRequest getOrgRequest(HttpServletRequest req) {
if (req instanceof XssAndSqlHttpServletRequestWrapper) {
return ((XssAndSqlHttpServletRequestWrapper) req).getOrgRequest();
}
return req;
}
/**
*
* 防止xss跨脚本攻击(替换，根据实际情况调整)
*/
public String stripXSSAndSql(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(
"<[\r\n| | ]*script[\r\n| | ]*>(.*?)<!--[\r\n| | ]*script[\r\n| | ]*-->", Pattern.CASE_INSENSITIVE);
value = scriptPattern.matcher(value).replaceAll("");
// Avoid anything in a
// src="http://www.yihaomen.com/article/java/..." type of
// e-xpression
scriptPattern = Pattern.compile("src[\r\n| | ]*=[\r\n| | ]*[\\\"|\\\'](.*?)[\\\"|\\\']",
Pattern.CASE_INSENSITIVE | Pattern.MULTILINE | Pattern.DOTALL);
value = scriptPattern.matcher(value).replaceAll("");
// Remove any lonesome tag
scriptPattern = Pattern.compile("<!--[\r\n| | ]*script[\r\n| | ]*-->", Pattern.CASE_INSENSITIVE);
value = scriptPattern.matcher(value).replaceAll("");
// Remove any lonesome <script ...> tag
scriptPattern = Pattern.compile("<[\r\n| | ]*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 e-xpression(...) expressions
scriptPattern = Pattern.compile("e-xpression\\((.*?)\\)",
Pattern.CASE_INSENSITIVE | Pattern.MULTILINE | Pattern.DOTALL);
value = scriptPattern.matcher(value).replaceAll("");
// Avoid javascript:... expressions
scriptPattern = Pattern.compile("javascript[\r\n| | ]*:[\r\n| | ]*", Pattern.CASE_INSENSITIVE);
value = scriptPattern.matcher(value).replaceAll("");
// Avoid vbscript:... expressions
scriptPattern = Pattern.compile("vbscript[\r\n| | ]*:[\r\n| | ]*", Pattern.CASE_INSENSITIVE);
value = scriptPattern.matcher(value).replaceAll("");
// Avoid οnlοad= expressions
scriptPattern = Pattern.compile("onload(.*?)=",
Pattern.CASE_INSENSITIVE | Pattern.MULTILINE | Pattern.DOTALL);
value = scriptPattern.matcher(value).replaceAll("");
}
return value;
}
public boolean checkXSSAndSql(String value) {
boolean flag = false;
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(
"<[\r\n| | ]*script[\r\n| | ]*>(.*?)</[\r\n| | ]*script[\r\n| | ]*>", Pattern.CASE_INSENSITIVE);
flag = scriptPattern.matcher(value).find();
if (flag) {
return flag;
}
// Avoid anything in a
// src="http://www.yihaomen.com/article/java/..." type of
// e-xpression
scriptPattern = Pattern.compile("src[\r\n| | ]*=[\r\n| | ]*[\\\"|\\\'](.*?)[\\\"|\\\']",
Pattern.CASE_INSENSITIVE | Pattern.MULTILINE | Pattern.DOTALL);
flag = scriptPattern.matcher(value).find();
if (flag) {
return flag;
}
// Remove any lonesome </script> tag
scriptPattern = Pattern.compile("<!--[\r\n| | ]*script[\r\n| | ]*-->", Pattern.CASE_INSENSITIVE);
flag = scriptPattern.matcher(value).find();
if (flag) {
return flag;
}
// Remove any lonesome <script ...> tag
scriptPattern = Pattern.compile("<[\r\n| | ]*script(.*?)>",
Pattern.CASE_INSENSITIVE | Pattern.MULTILINE | Pattern.DOTALL);
flag = scriptPattern.matcher(value).find();
if (flag) {
return flag;
}
// Avoid eval(...) expressions
scriptPattern = Pattern.compile("eval\\((.*?)\\)",
Pattern.CASE_INSENSITIVE | Pattern.MULTILINE | Pattern.DOTALL);
flag = scriptPattern.matcher(value).find();
if (flag) {
return flag;
}
// Avoid e-xpression(...) expressions
scriptPattern = Pattern.compile("e-xpression\\((.*?)\\)",
Pattern.CASE_INSENSITIVE | Pattern.MULTILINE | Pattern.DOTALL);
flag = scriptPattern.matcher(value).find();
if (flag) {
return flag;
}
// Avoid javascript:... expressions
scriptPattern = Pattern.compile("javascript[\r\n| | ]*:[\r\n| | ]*", Pattern.CASE_INSENSITIVE);
flag = scriptPattern.matcher(value).find();
if (flag) {
return flag;
}
// Avoid vbscript:... expressions
scriptPattern = Pattern.compile("vbscript[\r\n| | ]*:[\r\n| | ]*", Pattern.CASE_INSENSITIVE);
flag = scriptPattern.matcher(value).find();
if (flag) {
return flag;
}
// Avoid οnlοad= expressions
scriptPattern = Pattern.compile("onload(.*?)=",
Pattern.CASE_INSENSITIVE | Pattern.MULTILINE | Pattern.DOTALL);
flag = scriptPattern.matcher(value).find();
if (flag) {
return flag;
}
flag = checkSqlKeyWords(value);
}
return flag;
}
public boolean checkSqlKeyWords(String value){
String paramValue = value;
for (String keyword : notAllowedKeyWords) {
if (paramValue.length() > keyword.length() + 4
&& (paramValue.contains(" "+keyword)||paramValue.contains(keyword+" ")||paramValue.contains(" "+keyword+" "))) {
logger.error(this.getRequestURI()+ "参数中包含不允许sql的关键词(" + keyword
+ ")");
return true;
}
}
return false;
}
public final boolean checkParameter() {
@SuppressWarnings({ "unchecked", "rawtypes" })
Map<String, String[]> submitParams = new HashMap(parameterMap);
Set<String> submitNames = submitParams.keySet();
for (String submitName : submitNames) {
Object submitValues = submitParams.get(submitName);
if ((submitValues instanceof String)) {
if (checkXSSAndSql((String) submitValues)) {
return true;
}
} else if ((submitValues instanceof String[])) {
for (String submitValue : (String[])submitValues){
if (checkXSSAndSql(submitValue)) {
return true;
}
}
}
}
return false;
}
@Override
public BufferedReader getReader() throws IOException {
return new BufferedReader(new InputStreamReader(getInputStream()));
}
@Override
public ServletInputStream getInputStream() throws IOException {
final ByteArrayInputStream bais = new ByteArrayInputStream(body);
return new ServletInputStream() {
@Override
public int read() throws IOException {
return bais.read();
}
@Override
public boolean isFinished() {
// TODO Auto-generated method stub
return false;
}
@Override
public boolean isReady() {
// TODO Auto-generated method stub
return false;
}
@Override
public void setReadListener(ReadListener arg0) {
// TODO Auto-generated method stub
}
};
}
}②：把请求过滤类XssAndSqlHttpServletRequestWrapper添加到Filter中
注入容器
import com.fwpt.common.core.config.XssAndSqlHttpServletRequestWrapper;
import org.apache.commons.lang3.StringUtils;
import org.springframework.stereotype.Component;
import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.PrintWriter;
/**
* @author code
* @version 1.0
* @Date 2023/2/7 10:40
* @Description ${sql xss过滤器}
*/
@WebFilter
@Component
public class CrosXssFilter implements Filter {
@Override
public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
HttpServletRequest request = (HttpServletRequest) servletRequest;
//跨域设置
// if(servletResponse instanceof HttpServletResponse){
// HttpServletResponse httpServletResponse=(HttpServletResponse)servletResponse;
// //通过在响应 header 中设置 ‘*' 来允许来自所有域的跨域请求访问。
// httpServletResponse.setHeader("Access-Control-Allow-Origin", "*");
// //通过对 Credentials 参数的设置，就可以保持跨域 Ajax 时的 Cookie
// //设置了Allow-Credentials，Allow-Origin就不能为*,需要指明具体的url域
// //httpServletResponse.setHeader("Access-Control-Allow-Credentials", "true");
// //请求方式
// httpServletResponse.setHeader("Access-Control-Allow-Methods", "*");
// //(预检请求)的返回结果(即 Access-Control-Allow-Methods 和Access-Control-Allow-Headers 提供的信息) 可以被缓存多久
// httpServletResponse.setHeader("Access-Control-Max-Age", "86400");
// //首部字段用于预检请求的响应。其指明了实际请求中允许携带的首部字段
// httpServletResponse.setHeader("Access-Control-Allow-Headers", "*");
// }
XssAndSqlHttpServletRequestWrapper xssRequest=new XssAndSqlHttpServletRequestWrapper(request);
String method = ((HttpServletRequest) request).getMethod();
String param = "";
if ("POST".equalsIgnoreCase(method)) {
param = this.getBodyString(xssRequest.getReader());
if(StringUtils.isNotBlank(param)){
if(xssRequest.checkXSSAndSql(param)){
servletResponse.setCharacterEncoding("UTF-8");
servletResponse.setContentType("application/json;charset=UTF-8");
PrintWriter out = servletResponse.getWriter();
out.write("param is invalid");
return;
}
}
}
if (xssRequest.checkParameter()) {
servletResponse.setCharacterEncoding("UTF-8");
servletResponse.setContentType("application/json;charset=UTF-8");
PrintWriter out = servletResponse.getWriter();
out.write("param is invalid");
return;
}
filterChain.doFilter(xssRequest, servletResponse);
}
// 获取request请求body中参数
public String getBodyString(BufferedReader br) {
String inputLine;
String str = "";
try {
while ((inputLine = br.readLine()) != null) {
str += inputLine;
}
br.close();
} catch (IOException e) {
e.printStackTrace();
}
return str;
}
@Override
public void destroy() {
}
}总结
以上为个人经验，希望能给大家一个参考，也希望大家多多支持。
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