XSS漏洞与SQL注入漏洞解决方案
- 跨站脚本攻击的原理
XSS又叫CSS (Cross Site Script) ，跨站脚本攻击。它指的是恶意攻击者往Web页面里插入恶意脚本代码，而程序对于用户输入内容未过滤，当用户浏览该页之时，嵌入其中Web里面的脚本代码会被执行，从而达到恶意攻击用户的特殊目的。
跨站脚本攻击的危害：窃取cookie、放蠕虫、网站钓鱼 …
跨站脚本攻击的分类主要有：存储型XSS、反射型XSS、DOM型XSS
- SQL注入攻击的原理：
使用用户输入的参数拼凑SQL查询语句，使用户可以控制SQL查询语句。
- XSS漏洞及SQL注入过滤器参考：
1.XssReqFilter
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;
import com.talent.zdjf.wrapper.XssHttpServletRequestWrapper;
public class XssReqFilter implements Filter {
FilterConfig filterConfig = null;
@Override
public void destroy() {
this.filterConfig = null;
}
@Override
public void doFilter(ServletRequest request, ServletResponse response,
FilterChain chain) throws IOException, ServletException {
XssHttpServletRequestWrapper xssRequest = new XssHttpServletRequestWrapper(
(HttpServletRequest) request);
chain.doFilter(xssRequest, response);
}
@Override
public void init(FilterConfig filterConfig) throws ServletException {
this.filterConfig = filterConfig;
}
}2.XssHttpServletRequestWrapper
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.regex.Pattern;
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。
* 如果需要获得原始的值，则通过super.getParameterValues(name)来获取
* getParameterNames,getParameterValues和getParameterMap也可能需要覆盖
*/
@Override
public String getParameter(String name) {
// System.out.println("XssFilter处理前的 Value = " + super.getParameter(name));
String value = super.getParameter(xssEncode(name));
if (value != null) {
value = xssEncode(value);
}
// System.out.println("XssFilter处理后的 Value = " + value);
return value;
}
/**
* 覆盖getParameterValues方法，将参数名和参数值都做xss过滤。
*/
@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 Map getParameterMap() {
HashMap paramMap = (HashMap) super.getParameterMap();
paramMap = (HashMap) paramMap.clone();
for (Iterator iterator = paramMap.entrySet().iterator(); iterator.hasNext();) {
Map.Entry entry = (Map.Entry) iterator.next();
String[] values = entry.getValue();
for (int i = 0; i < values.length; i++) {
if (values[i] instanceof String) {
values[i] = xssEncode(values[i]);
}
}
entry.setValue(values);
}
return paramMap;
}
public String getQueryString() {
String value = super.getQueryString();
if (value != null) {
value = xssEncode(value);
value = value.replaceAll("＆", "&").replaceAll("＝", "=");
}
return value;
}
/**
* 覆盖getHeader方法，将参数名和参数值都做xss过滤。
* 如果需要获得原始的值，则通过super.getHeaders(name)来获取
* 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;
}
public String escape(String 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('（');// 全角左括号
// break;
// case ')':
// sb.append('）');// 全角右括号
// break;
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('＼');// 全角斜线
break;
case '%':
sb.append('％'); // 全角冒号
break;
default:
sb.append(c);
break;
}
}
return sb.toString();
}
/**
* 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
*/
public String xssEncode(String s) {
if (s == null || s.isEmpty()) {
return s;
}
String result = stripXSS(s);
if (null != result) {
result = escape(result);
}
return result;
}
private String stripXSS(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("",
Pattern.CASE_INSENSITIVE);
value = scriptPattern.matcher(value).replaceAll("");
scriptPattern = Pattern.compile("alert(.*?)",
Pattern.CASE_INSENSITIVE);
value = scriptPattern.matcher(value).replaceAll("");
// Avoid anything in a src='...' type of expression
scriptPattern = Pattern.compile("src[\r\n]*=[\r\n]*\\\'(.*?)\\\'",
Pattern.CASE_INSENSITIVE | Pattern.MULTILINE
| Pattern.DOTALL);
value = scriptPattern.matcher(value).replaceAll("");
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("",
Pattern.CASE_INSENSITIVE);
value = scriptPattern.matcher(value).replaceAll("");
// Remove any lonesome