什么是SQL攻击、什么是XSS攻击
SQL 攻击:把SQL命令插入到Web表单并提交,欺骗服务器执行恶意的SQL命令。
XSS 攻击:向有XSS漏洞的网站中输入(传入)恶意的HTML代码,当其它用户浏览该网站时,这段HTML代码会自动执行,从而达到攻击的目的。
创建拦截器第一步:
创建XssAndSqlHttpServletRequestWrapper包装器,这是实现XSS和SQL过滤的关键,在其内重写了getParameter,getParameterValues,getHeader等方法,对http请求内的参数进行了过滤。
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public class XssAndSqlHttpServletRequestWrapper extends HttpServletRequestWrapper {
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 = ();
body = (());
}
// 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>(());
return ();
}
/**
* 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(name)来获取<br/>
* getParameterNames,getParameterValues和getParameterMap也可能需要覆盖
*/
@Override
public String getParameter(String name) {
String[] results = (name);
if (results == null || <= 0)
return null;
else {
String value = results[0];
if (value != null) {
value = xssEncode(value);
}
return value;
}
}
/**
* 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 = (name);
if (results == null || <= 0)
return null;
else {
int 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(name)来获取<br/>
* getHeaderNames 也可能需要覆盖
*/
@Override
public String getHeader(String name) {
String value = (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 static String xssEncode(String s) {
if (s == null || ()) {
return s;
} else {
s = stripXSSAndSql(s);
}
StringBuilder sb = new StringBuilder(() + 16);
for (int i = 0; i < (); i++) {
char c = (i);
switch (c) {
case '>':
(">");// 转义大于号
break;
case '<':
("<");// 转义小于号
break;
// case '\'':
// ("'");// 转义单引号
// break;
// case '\"':
// (""");// 转义双引号
// break;
case '&':
("&");// 转义&
break;
case '#':
("#");// 转义#
break;
default:
(c);
break;
}
}
return ();
}
/**
* 获取最原始的request
*
* @return
*/
public HttpServletRequest getOrgRequest() {
return orgRequest;
}
/**
* 审查参数的具体方法
* @param value
* @return
*/
public static 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 = ().canonicalize(value);
// Avoid null characters
/** value = ("", ""); ***/
// Avoid anything between script tags
Pattern scriptPattern = (
"<[\r\n| | ]*script[\r\n| | ]*>(.*?)</[\r\n| | ]*script[\r\n| | ]*>", Pattern.CASE_INSENSITIVE);
flag = (value).find();
if (flag) {
return flag;
}
// Avoid anything in a
// src="/article/java/..." type of
// e-xpression
scriptPattern = ("src[\r\n| | ]*=[\r\n| | ]*[\\\"|\\\'](.*?)[\\\"|\\\']",
Pattern.CASE_INSENSITIVE | | );
flag = (value).find();
if (flag) {
return flag;
}
// Remove any lonesome </script> tag
scriptPattern = ("</[\r\n| | ]*script[\r\n| | ]*>", Pattern.CASE_INSENSITIVE);
flag = (value).find();
if (flag) {
return flag;
}
// Remove any lonesome <script ...> tag
scriptPattern = ("<[\r\n| | ]*script(.*?)>",
Pattern.CASE_INSENSITIVE | | );
flag = (value).find();
if (flag) {
return flag;
}
// Avoid eval(...) expressions
scriptPattern = ("eval\\((.*?)\\)",
Pattern.CASE_INSENSITIVE | | );
flag = (value).find();
if (flag) {
return flag;
}
// Avoid e-xpression(...) expressions
scriptPattern = ("e-xpression\\((.*?)\\)",
Pattern.CASE_INSENSITIVE | | );
flag = (value).find();
if (flag) {
return flag;
}
// Avoid javascript:... expressions
scriptPattern = ("javascript[\r\n| | ]*:[\r\n| | ]*", Pattern.CASE_INSENSITIVE);
flag = (value).find();
if (flag) {
return flag;
}
// Avoid vbscript:... expressions
scriptPattern = ("vbscript[\r\n| | ]*:[\r\n| | ]*", Pattern.CASE_INSENSITIVE);
flag = (value).find();
if (flag) {
return flag;
}
// Avoid οnlοad= expressions
scriptPattern = ("onload(.*?)=",
Pattern.CASE_INSENSITIVE | | );
flag = (value).find();
if (flag) {
return flag;
}
scriptPattern = ("\\b(and|exec|insert|select|drop|grant|alter|delete|update|count|chr|mid|master|truncate|char|declare|or)\\b|(\\*|;|\\+|'|%)",
Pattern.CASE_INSENSITIVE | | );
flag = (value).find();
if (flag) {
return flag;
}
}
return flag;
}
/**
* 检查参数方法
* @return
*/
public final boolean checkParameter() {
Map<String, String[]> submitParams = new HashMap(parameterMap);
Set<String> submitNames = ();
for (String submitName : submitNames) {
Object submitValues = (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;
}
/**
* 获取最原始的request的静态方法
*
* @return
*/
public static 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 static 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 = ().canonicalize(value);
// Avoid null characters
/** value = ("", ""); ***/
// Avoid anything between script tags
Pattern scriptPattern = (
"<[\r\n| | ]*script[\r\n| | ]*>(.*?)</[\r\n| | ]*script[\r\n| | ]*>", Pattern.CASE_INSENSITIVE);
value = (value).replaceAll("");
// Avoid anything in a
// src="/article/java/..." type of
// e-xpression
scriptPattern = ("src[\r\n| | ]*=[\r\n| | ]*[\\\"|\\\'](.*?)[\\\"|\\\']",
Pattern.CASE_INSENSITIVE | | );
value = (value).replaceAll("");
// Remove any lonesome </script> tag
scriptPattern = ("</[\r\n| | ]*script[\r\n| | ]*>", Pattern.CASE_INSENSITIVE);
value = (value).replaceAll("");
// Remove any lonesome <script ...> tag
scriptPattern = ("<[\r\n| | ]*script(.*?)>",
Pattern.CASE_INSENSITIVE | | );
value = (value).replaceAll("");
// Avoid eval(...) expressions
scriptPattern = ("eval\\((.*?)\\)",
Pattern.CASE_INSENSITIVE | | );
value = (value).replaceAll("");
// Avoid e-xpression(...) expressions
scriptPattern = ("e-xpression\\((.*?)\\)",
Pattern.CASE_INSENSITIVE | | );
value = (value).replaceAll("");
// Avoid javascript:... expressions
scriptPattern = ("javascript[\r\n| | ]*:[\r\n| | ]*", Pattern.CASE_INSENSITIVE);
value = (value).replaceAll("");
// Avoid vbscript:... expressions
scriptPattern = ("vbscript[\r\n| | ]*:[\r\n| | ]*", Pattern.CASE_INSENSITIVE);
value = (value).replaceAll("");
// Avoid οnlοad= expressions
scriptPattern = ("onload(.*?)=",
Pattern.CASE_INSENSITIVE | | );
value = (value).replaceAll("");
}
return value;
}
/**
**application/x- www-form-urlencoded是Post请求默认的请求体内容类型,也是form表单默认的类型。
* Servlet API规范中对该类型的请求内容提供了()方法来获取请求参数值。
* 但当请求内容不是该类型时,需要调用()或()方法来获取请求内容值。
*/
/**
* 获取请求内容
* @return
* @throws IOException
*/
@Override
public BufferedReader getReader() throws IOException {
return new BufferedReader(new InputStreamReader(getInputStream()));
}
/**
* 返回请求内容字节流,多用于文件上传,
* ()是对前者返回内容的封装,可以让调用者更方便字符内容的处理(不用自己先获取字节流再做字符流的转换操作)
* @return
* @throws IOException
*/
@Override
public ServletInputStream getInputStream() throws IOException {
final ByteArrayInputStream bais = new ByteArrayInputStream(body);
return new ServletInputStream() {
@Override
public int read() throws IOException {
return ();
}
@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
}
};
}
}
创建拦截器第二步:
编写过滤器
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import .;
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/**
* 防止XSS 攻击和SQL注入攻击的Filter
* @ClassName: XssAndSqlFilter
* @Description:TODO(这里用一句话描述这个类的作用)
* @author:
* @date: 2021年3月22日 下午2:29:12
*
* @Copyright: 2021
* 注意:
*/
public class XssAndSqlFilter implements Filter {
@Override
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
throws IOException, ServletException {
String method = "GET";//设置初始值
String param = "";
XssAndSqlHttpServletRequestWrapper xssRequest = null;
if (request instanceof HttpServletRequest) {//判断左边的对象是否是它右边对象的实例
method = ((HttpServletRequest) request).getMethod();//得到请求URL地址时使用的方法
xssRequest = new XssAndSqlHttpServletRequestWrapper((HttpServletRequest) request);//创建对象
}
if ("POST".equalsIgnoreCase(method)) {//判断是否为post
param = (());//获取参数
if((param)){//等价于 str != null && > 0 && ().length > 0
if((param)){//进行参数审查
("UTF-8");
("application/json;charset=UTF-8");
PrintWriter out = ();
((("401", "您所访问的页面请求中有违反安全规则元素存在,拒绝访问!")));
return;
}
}
}
/**
* 检查参数的时候 同时检查请求的方法
* 只检查get请求方法和post请求方法的的参数的数据是否合法
* 并不是所有参数都要检查,首先必须是一个get或者post,再去校验参数
* 因为PUT方法在进行参数审查的时候没办法通过所以直接过滤掉
*/
if (()&&(("POST") || ("GET"))){
("UTF-8");
("application/json;charset=UTF-8");
PrintWriter out = ();
((("401", "您所访问的页面请求中有违反安全规则元素存在,拒绝访问!")));
return;
}
(xssRequest, response);
}
// 获取request请求body中参数
public static String getBodyString(BufferedReader br) {
String inputLine;
String str = "";
try {
while ((inputLine = ()) != null) {
str += inputLine;
}
();
} catch (IOException e) {
("IOException: " + e);
}
return str;
}
}
创建拦截器第三步
在webconfig中注册过滤器XssAndSqlFilter
@Configuration
@EnableWebMvc
public class SpringMVCConfig extends WebMvcConfigurerAdapter {
@Bean
public FilterRegistrationBean xssFilterRegistrationBean() {
// 创建一个自定义的 Filter
FilterRegistrationBean filterRegistrationBean = new FilterRegistrationBean();
(new XssAndSqlFilter());
(1);
(true);
("/*");
// 过滤指定请求地址
Map<String, String> initParameters = new HashMap<String, String>();
("excludes", "/auth/login,/auth/code,/auth/phone,//**,/swagger-resources/**,/webjars/**,/v2/api-docs/**,/upload_file/**");
("isIncludeRichText", "true");
(initParameters);
return filterRegistrationBean;
}
}
备注
-
excludes用于配置不需要参数过滤的请求url。
-
isIncludeRichText默认为true,主要用于设置富文本内容是否需要过滤。