**JAVA解决XSS漏洞**
XSS是一种经常出现在web应用中的计算机安全漏洞,它允许恶意web用户将代码植入到提供给其它用户使用的页面中。比如这些代码包括HTML代码和客户端脚本。攻击者利用XSS漏洞旁路掉访问控制——例如同源策略(same origin policy)。这种类型的漏洞由于被黑客用来编写危害性更大的网络钓鱼(Phishing)攻击而变得广为人知。对于跨站脚本攻击,黑客界共识是:跨站脚本攻击是新型的“缓冲区溢出攻击“,而JavaScript是新型的“ShellCode”。简单的可以理解为在你们页面内容中镶嵌一些恶意的js脚本。
一般比较容易出现这个问题的是java的jsp页面数据回显包含前台提交的一些恶意的js代码,我们只要针对这些恶意的代码进行过滤掉就好了。
现在比较流行的就是过滤器,其实原理很简单,我们对httpservletrequest的获取请求参数的方法进行装饰包装就可以,在装饰的过程中对参数中的特殊字符进行过滤掉。
过滤器:
public class LoginFilter implements Filter {
@Override
public void init(FilterConfig filterConfig) throws ServletException {
}
@Override
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
throws IOException, ServletException {
chain.doFilter(new XSSRequestWrapper((HttpServletRequest) request), response);
}
@Override
public void destroy() {
}
}
HttpServletRequest的装饰类:
public class XSSRequestWrapper extends HttpServletRequestWrapper {
public XSSRequestWrapper(HttpServletRequest request) {
super(request);
}
@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] = StringEscapeUtils.escapeHtml4(values[i]);
encodedValues[i] = cleanXSS(encodedValues[i]);
}
return encodedValues;
}
@Override
public String getParameter(String parameter) {
String value = super.getParameter(parameter);
return stripXSS(value);
}
@Override
public String getHeader(String name) {
String value = super.getHeader(name);
return stripXSS(value);
}
private String stripXSS(String value) {
if (value != null) {
value = value.replaceAll("", "");
Pattern scriptPattern = Pattern.compile("<script>(.*?)</script>", Pattern.CASE_INSENSITIVE);
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("");
scriptPattern = Pattern.compile("src[\r\n]*=[\r\n]*\\\"(.*?)\\\"",
Pattern.CASE_INSENSITIVE | Pattern.MULTILINE | Pattern.DOTALL);
value = scriptPattern.matcher(value).replaceAll("");
scriptPattern = Pattern.compile("</script>", Pattern.CASE_INSENSITIVE);
value = scriptPattern.matcher(value).replaceAll("");
scriptPattern = Pattern.compile("<script(.*?)>",
Pattern.CASE_INSENSITIVE | Pattern.MULTILINE | Pattern.DOTALL);
value = scriptPattern.matcher(value).replaceAll("");
scriptPattern = Pattern.compile("eval\\((.*?)\\)",
Pattern.CASE_INSENSITIVE | Pattern.MULTILINE | Pattern.DOTALL);
value = scriptPattern.matcher(value).replaceAll("");
scriptPattern = Pattern.compile("expression\\((.*?)\\)",
Pattern.CASE_INSENSITIVE | Pattern.MULTILINE | Pattern.DOTALL);
value = scriptPattern.matcher(value).replaceAll("");
scriptPattern = Pattern.compile("javascript:", Pattern.CASE_INSENSITIVE);
value = scriptPattern.matcher(value).replaceAll("");
scriptPattern = Pattern.compile("vbscript:", Pattern.CASE_INSENSITIVE);
value = scriptPattern.matcher(value).replaceAll("");
scriptPattern = Pattern.compile("onload(.*?)=",
Pattern.CASE_INSENSITIVE | Pattern.MULTILINE | Pattern.DOTALL);
value = scriptPattern.matcher(value).replaceAll("");
}
return value;
}
private String cleanXSS(String value) {
// You'll need to remove the spaces from the html entities below
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;
}
}
,别忘记把过滤器配置到web.xml 这样就解决了XSS攻击.