Spring 防御CSRF、XSS和SQL注入攻击

对每个post请求的参数过滤一些关键字，替换成安全的，例如：< > ' " \ /  # &
方法是实现一个自定义的HttpServletRequestWrapper，然后在Filter里面调用它，替换掉getParameter函数即可。

首先添加一个XssHttpServletRequestWrapper:

package com.ibm.web.beans;

import java.util.Enumeration;

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

public class XssHttpServletRequestWrapper extends HttpServletRequestWrapper {
public XssHttpServletRequestWrapper(HttpServletRequest servletRequest) {
super(servletRequest);
}
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] = cleanXSS(values[i]);
}
return encodedValues;
}
public String getParameter(String parameter) {
String value = super.getParameter(parameter);
if (value == null) {
return null;
}
return cleanXSS(value);
}
public String getHeader(String name) {
String value = super.getHeader(name);
if (value == null)
return null;
return cleanXSS(value);
}
private String cleanXSS(String value) {
//这里特意 加多个空格.... 方便 csdn显示 ,如 <  ==>  & lt;
 value = value.replaceAll("<", "& lt;").replaceAll(">", "& gt;");
      value = value.replaceAll("\\(", "& #40;").replaceAll("\\)", "& #41;");
      value = value.replaceAll("'", "& #39;");
     value = value.replaceAll("eval\\((.*)\\)", "");
     value = value.replaceAll("[\\\"\\\'][\\s]*javascript:(.*)[\\\"\\\']", "\"\"");
     value = value.replaceAll("script", "");
return value;
}

}

然后添加一个过滤器XssFilter ：

package com.ibm.web.beans;

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 javax.servlet.http.HttpServletResponse;

public class XssFilter implements Filter {
FilterConfig filterConfig = null;

public void init(FilterConfig filterConfig) throws ServletException {
this.filterConfig = filterConfig;
}

public void destroy() {
this.filterConfig = null;
}

public void doFilter(ServletRequest request, ServletResponse response,
FilterChain chain) throws IOException, ServletException {
chain.doFilter(new XssHttpServletRequestWrapper(
(HttpServletRequest) request), response);
}
}

最后在web.xml里面配置一下，所有的请求的getParameter会被替换，如果参数里面 含有敏感词会被替换掉：

<filter>
<filter-name>XssSqlFilter</filter-name>
<filter-class>com.ibm.web.beans.XssFilter</filter-class>
</filter>
<filter-mapping>
<filter-name>XssSqlFilter</filter-name>
<url-pattern>/*</url-pattern>
<dispatcher>REQUEST</dispatcher>
</filter-mapping>