在网上查询了一些方法:
1.写一个过滤器和一个HttpServletRequestWrapper 并重写他的getParameterValues 和 getParameter方法,这个方法是可行的但是对@RequsetBody 参数无效
针对Spring MVC中的@RequestParam获取的参数,走的是getParameterValues()方法。
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;
public class XssFilter implements Filter {
public void init(FilterConfig config) throws ServletException {}
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
throws IOException, ServletException {
XssHttpServletRequestWrapper xssRequest = new XssHttpServletRequestWrapper((HttpServletRequest)request);
chain.doFilter(xssRequest, response);
}
public void destroy() {}
}
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;
public class XssHttpServletRequestWrapper extends HttpServletRequestWrapper {
HttpServletRequest orgRequest = null;
public XssHttpServletRequestWrapper(HttpServletRequest request) {
super(request);
orgRequest = request;
}
/**
* 覆盖getParameter方法,将参数名和参数值都做xss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[] 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] = xssEncode(values[i]);
}
return encodedValues;
}
@Override
public String getParameter(String name) {
String value = super.getParameter(xssEncode(name));
System.out.println("before name:"+name +" value:"+value);
if (value != null) {
value = xssEncode(value);
}
System.out.println("after name:"+name +" value:"+value);
return value;
}
/**
* 覆盖getHeader方法,将参数名和参数值都做xss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 || s.isEmpty()) {
return 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('>');// 全角大于号
break;
case '<':
sb.append('<');// 全角小于号
break;
case '\'':
sb.append('‘');// 全角单引号
break;
case '\"':
sb.append('“');// 全角双引号
break;
case '&':
sb.append('&');// 全角
break;
case '\\':
sb.append('\');// 全角斜线
break;
case '#':
sb.append('#');// 全角井号
break;
case '%': // < 字符的 URL 编码形式表示的 ASCII 字符(十六进制格式) 是: %3c
processUrlEncoder(sb, s, i);
break;
default:
sb.append(c);
break;
}
}
return sb.toString();
}
public static void processUrlEncoder(StringBuilder sb, String s, int index){
if(s.length() >= index + 2){
if(s.charAt(index+1) == '3' && (s.charAt(index+2) == 'c' || s.charAt(index+2) == 'C')){ // %3c, %3C
sb.append('<');
return;
}
if(s.charAt(index+1) == '6' && s.charAt(index+2) == '0'){ // %3c (0x3c=60)
sb.append('<');
return;
}
if(s.charAt(index+1) == '3' && (s.charAt(index+2) == 'e' || s.charAt(index+2) == 'E')){ // %3e, %3E
sb.append('>');
return;
}
if(s.charAt(index+1) == '6' && s.charAt(index+2) == '2'){ // %3e (0x3e=62)
sb.append('>');
return;
}
}
sb.append(s.charAt(index));
}
/**
* 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
*/
public static HttpServletRequest getOrgRequest(HttpServletRequest req) {
if (req instanceof XssHttpServletRequestWrapper) {
return ((XssHttpServletRequestWrapper) req).getOrgRequest();
}
return req;
}
}
<filter>
<filter-name>XssFilter</filter-name>
<filter-class>com.glodio.filter.XssFilter</filter-class>
</filter>
<filter-mapping>
<filter-name>XssFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
这种是把特殊字符串全部都换掉
2 使用spring 带的StringEscapeUtils 把特殊字段进行转义
System.out.println(StringEscapeUtils.escapeHtml("<a>dddd</a>"));
System.out.println(StringEscapeUtils.escapeHtml("<script>alert('111')</script>"));
//输出结果
<a>dddd</a>
<script>alert('111')</script>
直接对字段进行转义。
@InitBinder
protected void initBinder(WebDataBinder binder) {
// String类型转换,将所有传递进来的String进行HTML编码,防止XSS攻击
binder.registerCustomEditor(String.class, new PropertyEditorSupport() {
@Override
public void setAsText(String text) {
setValue(text == null ? null : StringEscapeUtils.escapeHtml(text.trim()));
}
@Override
public String getAsText() {
Object value = getValue();
return value != null ? value.toString() : "";
}
});
}
根据需要可以选择一种。
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