package com.ebiz.nmswxt_mhwz.web.filter;
import java.io.UnsupportedEncodingException;
import java.net.URLDecoder;
import java.util.regex.Pattern;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;
public class XssHttpServletRequestWrapper extends HttpServletRequestWrapper {
HttpServletRequest xssRequest = null;
public XssHttpServletRequestWrapper(HttpServletRequest request) {
super(request);
xssRequest = request;
}
@Override
public String getParameter(String name) {
String value = super.getParameter(replaceXSS(name));
if (value != null) {
value = replaceXSS(value);
}
return value;
}
@Override
public String[] getParameterValues(String name) {
String[] values = super.getParameterValues(replaceXSS(name));
if (values != null && values.length > 0) {
for (int i = 0; i < values.length; i++) {
values[i] = replaceXSS(values[i]);
}
}
return values;
}
@Override
public String getHeader(String name) {
String value = super.getHeader(replaceXSS(name));
if (value != null) {
value = replaceXSS(value);
}
return value;
}
/**
* 去除待带script、src的语句，转义替换后的value值
*/
public static String replaceXSS(String value) {
if (value != null) {
try {
value = value.replace("+", "%2B"); // '+' replace to '%2B'
value = URLDecoder.decode(value, "utf-8");
} catch (UnsupportedEncodingException e) {
} catch (IllegalArgumentException e) {
}
// Avoid null characters
value = value.replaceAll("\0", "");
// Avoid anything between script tags
Pattern scriptPattern = Pattern.compile("<script>(.*?)</script>", 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 </script> tag
scriptPattern = Pattern.compile("</script>", Pattern.CASE_INSENSITIVE);
value = scriptPattern.matcher(value).replaceAll("");
// Remove any lonesome <script ...> tag
scriptPattern = Pattern.compile("<script(.*?)>",
Pattern.CASE_INSENSITIVE | Pattern.MULTILINE | Pattern.DOTALL);
value = scriptPattern.matcher(value).replaceAll("");
// Avoid eval(...) expressions
scriptPattern = Pattern.compile("eval\\((.*?)\\)",
Pattern.CASE_INSENSITIVE | Pattern.MULTILINE | Pattern.DOTALL);
value = scriptPattern.matcher(value).replaceAll("");
// Avoid expression(...) expressions
scriptPattern = Pattern.compile("expression\\((.*?)\\)",
Pattern.CASE_INSENSITIVE | Pattern.MULTILINE | Pattern.DOTALL);
value = scriptPattern.matcher(value).replaceAll("");
// Avoid javascript:... expressions
scriptPattern = Pattern.compile("javascript:", Pattern.CASE_INSENSITIVE);
value = scriptPattern.matcher(value).replaceAll("");
// Avoid alert:... expressions
scriptPattern = Pattern.compile("alert", Pattern.CASE_INSENSITIVE);
value = scriptPattern.matcher(value).replaceAll("");
// Avoid onload= expressions
scriptPattern = Pattern.compile("onload(.*?)=",
Pattern.CASE_INSENSITIVE | Pattern.MULTILINE | Pattern.DOTALL);
value = scriptPattern.matcher(value).replaceAll("");
scriptPattern = Pattern.compile("vbscript[\r\n| | ]*:[\r\n| | ]*", Pattern.CASE_INSENSITIVE);
value = scriptPattern.matcher(value).replaceAll("");
}
return filter(value);
}
/**
* 过滤特殊字符
*/
public static String filter(String value) {
if (value == null) {
return null;
}
StringBuffer result = new StringBuffer(value.length());
for (int i = 0; i < value.length(); ++i) {
switch (value.charAt(i)) {
case '<':
result.append("<");
break;
case '>':
result.append(">");
break;
case '"':
result.append("\"");
break;
case '\'':
result.append("'");
break;
case '%':
result.append("%");
break;
case ';':
result.append(";");
break;
case '(':
result.append("(");
break;
case ')':
result.append(")");
break;
case '&':
result.append("&");
break;
case '+':
result.append("+");
break;
default:
result.append(value.charAt(i));
break;
}
}
return result.toString();
}
}
