出处： https://www.cnblogs.com/hero123/p/9091625.html
Java项目中XSS过滤器的使用方法。
简单介绍：
XSS : 跨站脚本攻击(Cross Site Scripting)，为不和层叠样式表(Cascading Style Sheets, CSS)的缩写混淆，故将跨站脚本攻击缩写为XSS。恶意攻击者往Web页面里插入恶意html代码，当用户浏览该页之时，嵌入其中Web里面的html代码会被执行，从而达到恶意攻击用户的特殊目的。
sql注入
所谓SQL注入，就是通过把SQL命令插入到Web表单提交或输入域名或页面请求的查询字符串，最终达到欺骗服务器执行恶意的SQL命令。具体来说，它是利用现有应用程序，将（恶意）的SQL命令注入到后台数据库引擎执行的能力，它可以通过在Web表单中输入（恶意）SQL语句得到一个存在安全漏洞的网站上的数据库，而不是按照设计者意图去执行SQL语句。
实现方式，共三步：
第一步：配置web.xml
<filter>
<filter-name>xssFilter</filter-name>
<filter-class>com.wfcm.xss.XssFilter</filter-class>
</filter>
<filter-mapping>
<filter-name>xssFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
第二步：过滤工具类
1.XSSFilter.java
package com.wfcm.xss;
import javax.servlet.*;
import javax.servlet.http.HttpServletRequest;
import java.io.IOException;
/**
* xss过滤
* @author xlf
* @email xlfbe696@gmail.com
* @date 2017年4月19日 上午10:41:42
*/
public class XssFilter implements Filter {
@Override
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);
}
@Override
public void destroy() {
}
}
2.XssHttpServletRequestWrapper
package com.wfcm.xss;
import org.apache.commons.lang.StringEscapeUtils;
import org.apache.commons.lang.StringUtils;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;
import java.util.LinkedHashMap;
import java.util.Map;
public class XssHttpServletRequestWrapper extends HttpServletRequestWrapper {
// 没被包装过的HttpServletRequest（特殊场景，需求自己过滤）
HttpServletRequest orgRequest;
// html过滤
private final static HTMLFilter htmlFilter = new HTMLFilter();
public XssHttpServletRequestWrapper(HttpServletRequest request) {
super(request);
orgRequest = request;
}
@Override
public String getParameter(String name) {
String value = super.getParameter(xssEncode(name));
if (StringUtils.isNotBlank(value)) {
value =xssEncode(value);
}
//SQL注入检查
// value = SQLFilter.sqlInject(value);
value = SQLFilter.sqlInject(value);
return StringEscapeUtils.unescapeHtml(value);
}
@Override
public String[] getParameterValues(String name) {
String[] parameters = super.getParameterValues(name);
if (parameters == null || parameters.length == 0) {
return null;
}
for (int i = 0; i < parameters.length; i++) {
parameters[i] = xssEncode(parameters[i]);
//SQL注入检查
// parameters[i] = SQLFilter.sqlInject(parameters[i]);
parameters[i] = SQLFilter.sqlInject(parameters[i]);
parameters[i] = StringEscapeUtils.unescapeHtml(parameters[i]);
}
return parameters;
}
@Override
public Map<String, String[]> getParameterMap() {
Map<String, String[]> map = new LinkedHashMap<>();
Map<String, String[]> parameters = super.getParameterMap();
for (String key : parameters.keySet()) {
String[] values = parameters.get(key);
for (int i = 0; i < values.length; i++) {
values[i] = xssEncode(values[i]);
//SQL注入检查
// values[i] = SQLFilter.sqlInject(values[i]);
values[i] = SQLFilter.sqlInject(values[i]);
values[i] = StringEscapeUtils.unescapeHtml(values[i]);
}
map.put(key, values);
}
return map;
}
@Override
public String getHeader(String name) {
String value = super.getHeader(xssEncode(name));
if (StringUtils.isNotBlank(value)) {
value = xssEncode(value);
}
//SQL注入检查
// value = SQLFilter.sqlInject(value);
value = SQLFilter.sqlInject(value);
return StringEscapeUtils.unescapeHtml(value);
}
private String xssEncode(String input) {
return htmlFilter.filter(input);
}
/**
* 获取最原始的request
*/
public HttpServletRequest getOrgRequest() {
return orgRequest;
}
/**
* 获取最原始的request
*/
public static HttpServletRequest getOrgRequest(HttpServletRequest request) {
if (request instanceof XssHttpServletRequestWrapper) {
return ((XssHttpServletRequestWrapper) request).getOrgRequest();
}
return request;
}
}
3.HTMLFilter
package com.wfcm.xss;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
import java.util.logging.Logger;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
/**
*
* HTML filtering utility for protecting against XSS (Cross Site Scripting).
*
* This code is licensed LGPLv3
*
* This code is a Java port of the original work in PHP by Cal Hendersen.
* http://code.iamcal.com/php/lib_filter/
*
* The trickiest part of the translation was handling the differences in regex handling
* between PHP and Java. These resources were helpful in the process:
*
* http://java.sun.com/j2se/1.4.2/docs/api/java/util/regex/Pattern.html
* http://us2.php.net/manual/en/reference.pcre.pattern.modifiers.php
* http://www.regular-expressions.info/modifiers.html
*
* A note on naming conventions: instance variables are prefixed with a "v"; global
* constants are in all caps.
*
* Sample use:
* String input = ...
* String clean = new HTMLFilter().filter( input );
*
* The class is not thread safe. Create a new instance if in doubt.
*
* If you find bugs or have suggestions on improvement (especially regarding
* performance), please contact us. The latest version of this
* source, and our contact details, can be found at http://xss-html-filter.sf.net
*
* @author Joseph O'Connell
* @author Cal Hendersen
* @author Michael Semb Wever
*/
public class HTMLFilter {
/** regex flag union representing /si modifiers in php **/
private static final int REGEX_FLAGS_SI = Pattern.CASE_INSENSITIVE | Pattern.DOTALL;
private static final Pattern P_COMMENTS = Pattern.compile("<!--(.*?)-->", Pattern.DOTALL);
private static final Pattern P_COMMENT = Pattern.compile("^!--(.*)--$", REGEX_FLAGS_SI);
private static final Pattern P_TAGS = Pattern.compile("<(.*?)>", Pattern.DOTALL);
private static final Pattern P_END_TAG = Pattern.compile("^/([a-z0-9]+)", REGEX_FLAGS_SI);
private static final Pattern P_START_TAG = Pattern.compile("^([a-z0-9]+)(.*?)(/?)$", REGEX_FLAGS_SI);
private static final Pattern P_QUOTED_ATTRIBUTES = Pattern.compile("([a-z0-9]+)=(["'])(.*?)\2", REGEX_FLAGS_SI);
private static final Pattern P_UNQUOTED_ATTRIBUTES = Pattern.compile("([a-z0-9]+)(=)([^"\s']+)", REGEX_FLAGS_SI);
private static final Pattern P_PROTOCOL = Pattern.compile("^([^:]+):", REGEX_FLAGS_SI);
private static final Pattern P_ENTITY = Pattern.compile("&#(\d+);?");
private static final Pattern P_ENTITY_UNICODE = Pattern.compile("&#x([0-9a-f]+);?");
private static final Pattern P_ENCODE = Pattern.compile("%([0-9a-f]{2});?");
private static final Pattern P_VALID_ENTITIES = Pattern.compile("&([^&;]*)(?=(;|&|$))");
private static final Pattern P_VALID_QUOTES = Pattern.compile("(>|^)([^<]+?)(<|$)", Pattern.DOTALL);
private static final Pattern P_END_ARROW = Pattern.compile("^>");
private static final Pattern P_BODY_TO_END = Pattern.compile("<([^>]*?)(?=<|$)");
private static final Pattern P_XML_CONTENT = Pattern.compile("(^|>)([^<]*?)(?=>)");
private static final Pattern P_STRAY_LEFT_ARROW = Pattern.compile("<([^>]*?)(?=<|$)");
private static final Pattern P_STRAY_RIGHT_ARROW = Pattern.compile("(^|>)([^<]*?)(?=>)");
private static final Pattern P_AMP = Pattern.compile("&");
private static final Pattern P_QUOTE = Pattern.compile(""");
private static final Pattern P_LEFT_ARROW = Pattern.compile("<");
private static final Pattern P_RIGHT_ARROW = Pattern.compile(">");
private static final Pattern P_BOTH_ARROWS = Pattern.compile("<>");
private static final Pattern P_DOUBLE_QUOT = Pattern.compile(""");
// @xxx could grow large... maybe use sesat's ReferenceMap
private static final ConcurrentMap<String,Pattern> P_REMOVE_PAIR_BLANKS = new ConcurrentHashMap<String, Pattern>();
private static final ConcurrentMap<String,Pattern> P_REMOVE_SELF_BLANKS = new ConcurrentHashMap<String, Pattern>();
/** set of allowed html elements, along with allowed attributes for each element **/
private final Map<String, List<String>> vAllowed;
/** counts of open tags for each (allowable) html element **/
private final Map<String, Integer> vTagCounts = new HashMap<String, Integer>();
/** html elements which must always be self-closing (e.g. "<img />") **/
private final String[] vSelfClosingTags;
/** html elements which must always have separate opening and closing tags (e.g. "<b></b>") **/
private final String[] vNeedClosingTags;
/** set of disallowed html elements **/
private final String[] vDisallowed;
/** attributes which should be checked for valid protocols **/
private final String[] vProtocolAtts;
/** allowed protocols **/
private final String[] vAllowedProtocols;
/** tags which should be removed if they contain no content (e.g. "<b></b>" or "<b />") **/
private final String[] vRemoveBlanks;
/** entities allowed within html markup **/
private final String[] vAllowedEntities;
/** flag determining whether comments are allowed in input String. */
private final boolean stripComment;
private final boolean encodeQuotes;
private boolean vDebug = false;
/**
* flag determining whether to try to make tags when presented with "unbalanced"
* angle brackets (e.g. "<b text </b>" becomes "<b> text </b>"). If set to false,
* unbalanced angle brackets will be html escaped.
*/
private final boolean alwaysMakeTags;
/** Default constructor.
*
*/
public