为解决存储型xss和sql注入漏洞,创建对应的全局过滤器

姜兴业
2023-12-01

1、存储型xss漏洞
系统由于未对参数过滤,导致可以存储html特殊标签,且返回的数据未经处理显示在web页面中导致存在存储型xss,攻击者可利用xss对用户发起鱼叉攻击获取cookie进入系统。为解决该问题,创建全局过滤器,涉及的类及步骤如下:
1)XssFilter.java

package com.chinacreator.c2.filter.xss;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
 
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.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
 
import org.apache.commons.lang3.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.core.annotation.Order;

 
 
/**
 * xss过滤
 */
@WebFilter(filterName = "XSSFilter", urlPatterns = "/*")
@Order(2)
public class XSSFilter implements Filter {
 
    //不拦截的地址
	private List<String> excludedList = new ArrayList<String>();
	
	public static Logger log = LoggerFactory.getLogger(XSSFilter.class);
	
	@Override
	public void init(FilterConfig config) throws ServletException {
 
        /*
		 * 这里只处理了不拦截的url地址,如果想不拦截某个字段,比如富文本字段,
		 * 需要自己在XssHttpServletRequestWrapper类中去添加逻辑
		 */
		excludedList.add("/proxy/aip/v1/currentappmenus");
		excludedList.add("/proxy/aip/v1/permissions/verify");
	}
 
	@Override
	public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
            throws IOException, ServletException {
		XssHttpServletRequestWrapper xssRequest = new XssHttpServletRequestWrapper(
				(HttpServletRequest) request);
		HttpServletRequest req = (HttpServletRequest) request;
		if ("POST".equals(req.getMethod().toUpperCase())) {
			String url = xssRequest.getServletPath();
			if(isExcluded(url)){
				chain.doFilter(request, response);
			}else{
				//使用XSS过滤
				log.info("使用XSS过滤");
				chain.doFilter(xssRequest, response);
			}
	    } else {
	    	chain.doFilter(request, response);
	    }
		
	}
 
	@Override
	public void destroy() {
	}
 
	/**
	 * 是否不拦截
	 * @param url	请求地址
	 * @return	true不拦截,false拦截
	 */
	private boolean isExcluded(String url){
		if(StringUtils.isBlank(url)){
			return false;
		}
		
		for (String excluded : excludedList) {
			if(url.indexOf(excluded) > -1){
				return true;
			}
		}
		return false;
	}
 
}

2)XssHttpServletRequestWrapper.java

package com.chinacreator.c2.filter.xss;
 
import org.apache.commons.lang3.StringEscapeUtils;
import org.apache.commons.lang3.StringUtils;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;
import java.util.LinkedHashMap;
import java.util.Map;
 
import java.io.ByteArrayInputStream;
import java.io.IOException;
import javax.servlet.ReadListener;
import javax.servlet.ServletInputStream;
import org.apache.commons.io.IOUtils;
import org.springframework.http.HttpHeaders;
import org.springframework.http.MediaType;
 
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;
        }
 
        
        /**
         * 过滤json参数
         */
        @Override
        public ServletInputStream getInputStream() throws IOException {
            String contentType = super.getHeader(HttpHeaders.CONTENT_TYPE);
            //非json类型,直接返回
            if(!(MediaType.APPLICATION_JSON_VALUE.
                equalsIgnoreCase(contentType) || 
                MediaType.APPLICATION_JSON_UTF8_VALUE.
                equalsIgnoreCase(contentType))){
                return super.getInputStream();
            }
 
            //为空,直接返回
            String json = IOUtils.toString(super.getInputStream(), "utf-8");
            if (StringUtils.isBlank(json)) {
                return super.getInputStream();
            }
 
            //xss过滤
            json =xssEncode(json);
            json = StringEscapeUtils.unescapeHtml4(json);
 
            final ByteArrayInputStream bis = 
                new ByteArrayInputStream(json.getBytes("utf-8"));
            
            return new ServletInputStream() {
                @Override
                public boolean isFinished() {
                    return true;
                }
 
                @Override
                public boolean isReady() {
                    return true;
                }
 
                @Override
                public void setReadListener(ReadListener readListener) {
                }
 
                @Override
                public int read() throws IOException {
                    return bis.read();
                }
            };
        }
 
 
        @Override
        public String getParameter(String name) {
            String value = super.getParameter(xssEncode(name));
            if (StringUtils.isNotBlank(value)) {
                value =xssEncode(value);
            }
 
            return StringEscapeUtils.unescapeHtml4(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]);
                parameters[i] = StringEscapeUtils.unescapeHtml4(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]);
                    values[i] = StringEscapeUtils.unescapeHtml4(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);
            }
 
            return StringEscapeUtils.unescapeHtml4(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.java

package com.chinacreator.c2.filter.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("&quot;");
 
    // @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 HTMLFilter() {
        vAllowed = new HashMap<>();
 
        final ArrayList<String> a_atts = new ArrayList<String>();
        a_atts.add("href");
        a_atts.add("target");
        vAllowed.put("a", a_atts);
 
        final ArrayList<String> img_atts = new ArrayList<String>();
        img_atts.add("src");
        img_atts.add("width");
        img_atts.add("height");
        img_atts.add("alt");
        vAllowed.put("img", img_atts);
 
        final ArrayList<String> no_atts = new ArrayList<String>();
        vAllowed.put("b", no_atts);
        vAllowed.put("strong", no_atts);
        vAllowed.put("i", no_atts);
        vAllowed.put("em", no_atts);
 
        vSelfClosingTags = new String[]{"img"};
        vNeedClosingTags = new String[]{"a", "b", "strong", "i", "em"};
        vDisallowed = new String[]{};
        vAllowedProtocols = new String[]{"http", "mailto", "https"}; // no ftp.
        vProtocolAtts = new String[]{"src", "href"};
        vRemoveBlanks = new String[]{"a", "b", "strong", "i", "em"};
        vAllowedEntities = new String[]{"amp", "gt", "lt", "quot"};
        stripComment = true;
        encodeQuotes = true;
        alwaysMakeTags = true;
    }
 
    /** Set debug flag to true. Otherwise use default settings. See the default constructor.
     *
     * @param debug turn debug on with a true argument
     */
    public HTMLFilter(final boolean debug) {
        this();
        vDebug = debug;
 
    }
 
    /** Map-parameter configurable constructor.
     *
     * @param conf map containing configuration. keys match field names.
     */
    public HTMLFilter(final Map<String,Object> conf) {
 
        assert conf.containsKey("vAllowed") : "configuration requires vAllowed";
        assert conf.containsKey("vSelfClosingTags") : "configuration requires vSelfClosingTags";
        assert conf.containsKey("vNeedClosingTags") : "configuration requires vNeedClosingTags";
        assert conf.containsKey("vDisallowed") : "configuration requires vDisallowed";
        assert conf.containsKey("vAllowedProtocols") : "configuration requires vAllowedProtocols";
        assert conf.containsKey("vProtocolAtts") : "configuration requires vProtocolAtts";
        assert conf.containsKey("vRemoveBlanks") : "configuration requires vRemoveBlanks";
        assert conf.containsKey("vAllowedEntities") : "configuration requires vAllowedEntities";
 
        vAllowed = Collections.unmodifiableMap((HashMap<String, List<String>>) conf.get("vAllowed"));
        vSelfClosingTags = (String[]) conf.get("vSelfClosingTags");
        vNeedClosingTags = (String[]) conf.get("vNeedClosingTags");
        vDisallowed = (String[]) conf.get("vDisallowed");
        vAllowedProtocols = (String[]) conf.get("vAllowedProtocols");
        vProtocolAtts = (String[]) conf.get("vProtocolAtts");
        vRemoveBlanks = (String[]) conf.get("vRemoveBlanks");
        vAllowedEntities = (String[]) conf.get("vAllowedEntities");
        stripComment =  conf.containsKey("stripComment") ? (Boolean) conf.get("stripComment") : true;
        encodeQuotes = conf.containsKey("encodeQuotes") ? (Boolean) conf.get("encodeQuotes") : true;
        alwaysMakeTags = conf.containsKey("alwaysMakeTags") ? (Boolean) conf.get("alwaysMakeTags") : true;
    }
 
    private void reset() {
        vTagCounts.clear();
    }
 
    private void debug(final String msg) {
        if (vDebug) {
            Logger.getAnonymousLogger().info(msg);
        }
    }
 
    //---------------------------------------------------------------
    // my versions of some PHP library functions
    public static String chr(final int decimal) {
        return String.valueOf((char) decimal);
    }
 
    public static String htmlSpecialChars(final String s) {
        String result = s;
        result = regexReplace(P_AMP, "&amp;", result);
        result = regexReplace(P_QUOTE, "&quot;", result);
        result = regexReplace(P_LEFT_ARROW, "&lt;", result);
        result = regexReplace(P_RIGHT_ARROW, "&gt;", result);
        return result;
    }
 
    //---------------------------------------------------------------
    /**
     * given a user submitted input String, filter out any invalid or restricted
     * html.
     *
     * @param input text (i.e. submitted by a user) than may contain html
     * @return "clean" version of input, with only valid, whitelisted html elements allowed
     */
    public String filter(final String input) {
        reset();
        String s = input;
 
        debug("************************************************");
        debug("              INPUT: " + input);
 
        s = escapeComments(s);
        debug("     escapeComments: " + s);
 
        s = balanceHTML(s);
        debug("        balanceHTML: " + s);
 
        s = checkTags(s);
        debug("          checkTags: " + s);
 
        s = processRemoveBlanks(s);
        debug("processRemoveBlanks: " + s);
 
        s = validateEntities(s);
        debug("    validateEntites: " + s);
 
        debug("************************************************\n\n");
        return s;
    }
 
    public boolean isAlwaysMakeTags(){
        return alwaysMakeTags;
    }
 
    public boolean isStripComments(){
        return stripComment;
    }
 
    private String escapeComments(final String s) {
        final Matcher m = P_COMMENTS.matcher(s);
        final StringBuffer buf = new StringBuffer();
        if (m.find()) {
            final String match = m.group(1); //(.*?)
            m.appendReplacement(buf, Matcher.quoteReplacement("<!--" + htmlSpecialChars(match) + "-->"));
        }
        m.appendTail(buf);
 
        return buf.toString();
    }
 
    private String balanceHTML(String s) {
        if (alwaysMakeTags) {
            //
            // try and form html
            //
            s = regexReplace(P_END_ARROW, "", s);
            s = regexReplace(P_BODY_TO_END, "<$1>", s);
            s = regexReplace(P_XML_CONTENT, "$1<$2", s);
 
        } else {
            //
            // escape stray brackets
            //
            s = regexReplace(P_STRAY_LEFT_ARROW, "&lt;$1", s);
            s = regexReplace(P_STRAY_RIGHT_ARROW, "$1$2&gt;<", s);
 
            //
            // the last regexp causes '<>' entities to appear
            // (we need to do a lookahead assertion so that the last bracket can
            // be used in the next pass of the regexp)
            //
            s = regexReplace(P_BOTH_ARROWS, "", s);
        }
 
        return s;
    }
 
    private String checkTags(String s) {
        Matcher m = P_TAGS.matcher(s);
 
        final StringBuffer buf = new StringBuffer();
        while (m.find()) {
            String replaceStr = m.group(1);
            replaceStr = processTag(replaceStr);
            m.appendReplacement(buf, Matcher.quoteReplacement(replaceStr));
        }
        m.appendTail(buf);
 
        s = buf.toString();
 
        // these get tallied in processTag
        // (remember to reset before subsequent calls to filter method)
        for (String key : vTagCounts.keySet()) {
            for (int ii = 0; ii < vTagCounts.get(key); ii++) {
                s += "</" + key + ">";
            }
        }
 
        return s;
    }
 
    private String processRemoveBlanks(final String s) {
        String result = s;
        for (String tag : vRemoveBlanks) {
            if(!P_REMOVE_PAIR_BLANKS.containsKey(tag)){
                P_REMOVE_PAIR_BLANKS.putIfAbsent(tag, Pattern.compile("<" + tag + "(\\s[^>]*)?></" + tag + ">"));
            }
            result = regexReplace(P_REMOVE_PAIR_BLANKS.get(tag), "", result);
            if(!P_REMOVE_SELF_BLANKS.containsKey(tag)){
                P_REMOVE_SELF_BLANKS.putIfAbsent(tag, Pattern.compile("<" + tag + "(\\s[^>]*)?/>"));
            }
            result = regexReplace(P_REMOVE_SELF_BLANKS.get(tag), "", result);
        }
 
        return result;
    }
 
    private static String regexReplace(final Pattern regex_pattern, final String replacement, final String s) {
        Matcher m = regex_pattern.matcher(s);
        return m.replaceAll(replacement);
    }
 
    private String processTag(final String s) {
        // ending tags
        Matcher m = P_END_TAG.matcher(s);
        if (m.find()) {
            final String name = m.group(1).toLowerCase();
            if (allowed(name)) {
                if (!inArray(name, vSelfClosingTags)) {
                    if (vTagCounts.containsKey(name)) {
                        vTagCounts.put(name, vTagCounts.get(name) - 1);
                        return "</" + name + ">";
                    }
                }
            }
        }
 
        // starting tags
        m = P_START_TAG.matcher(s);
        if (m.find()) {
            final String name = m.group(1).toLowerCase();
            final String body = m.group(2);
            String ending = m.group(3);
 
            //debug( "in a starting tag, name='" + name + "'; body='" + body + "'; ending='" + ending + "'" );
            if (allowed(name)) {
                String params = "";
 
                final Matcher m2 = P_QUOTED_ATTRIBUTES.matcher(body);
                final Matcher m3 = P_UNQUOTED_ATTRIBUTES.matcher(body);
                final List<String> paramNames = new ArrayList<String>();
                final List<String> paramValues = new ArrayList<String>();
                while (m2.find()) {
                    paramNames.add(m2.group(1)); //([a-z0-9]+)
                    paramValues.add(m2.group(3)); //(.*?)
                }
                while (m3.find()) {
                    paramNames.add(m3.group(1)); //([a-z0-9]+)
                    paramValues.add(m3.group(3)); //([^\"\\s']+)
                }
 
                String paramName, paramValue;
                for (int ii = 0; ii < paramNames.size(); ii++) {
                    paramName = paramNames.get(ii).toLowerCase();
                    paramValue = paramValues.get(ii);
 
//          debug( "paramName='" + paramName + "'" );
//          debug( "paramValue='" + paramValue + "'" );
//          debug( "allowed? " + vAllowed.get( name ).contains( paramName ) );
 
                    if (allowedAttribute(name, paramName)) {
                        if (inArray(paramName, vProtocolAtts)) {
                            paramValue = processParamProtocol(paramValue);
                        }
                        params += " " + paramName + "=\"" + paramValue + "\"";
                    }
                }
 
                if (inArray(name, vSelfClosingTags)) {
                    ending = " /";
                }
 
                if (inArray(name, vNeedClosingTags)) {
                    ending = "";
                }
 
                if (ending == null || ending.length() < 1) {
                    if (vTagCounts.containsKey(name)) {
                        vTagCounts.put(name, vTagCounts.get(name) + 1);
                    } else {
                        vTagCounts.put(name, 1);
                    }
                } else {
                    ending = " /";
                }
                return "<" + name + params + ending + ">";
            } else {
                return "";
            }
        }
 
        // comments
        m = P_COMMENT.matcher(s);
        if (!stripComment && m.find()) {
            return  "<" + m.group() + ">";
        }
 
        return "";
    }
 
    private String processParamProtocol(String s) {
        s = decodeEntities(s);
        final Matcher m = P_PROTOCOL.matcher(s);
        if (m.find()) {
            final String protocol = m.group(1);
            if (!inArray(protocol, vAllowedProtocols)) {
                // bad protocol, turn into local anchor link instead
                s = "#" + s.substring(protocol.length() + 1, s.length());
                if (s.startsWith("#//")) {
                    s = "#" + s.substring(3, s.length());
                }
            }
        }
 
        return s;
    }
 
    private String decodeEntities(String s) {
        StringBuffer buf = new StringBuffer();
 
        Matcher m = P_ENTITY.matcher(s);
        while (m.find()) {
            final String match = m.group(1);
            final int decimal = Integer.decode(match).intValue();
            m.appendReplacement(buf, Matcher.quoteReplacement(chr(decimal)));
        }
        m.appendTail(buf);
        s = buf.toString();
 
        buf = new StringBuffer();
        m = P_ENTITY_UNICODE.matcher(s);
        while (m.find()) {
            final String match = m.group(1);
            final int decimal = Integer.valueOf(match, 16).intValue();
            m.appendReplacement(buf, Matcher.quoteReplacement(chr(decimal)));
        }
        m.appendTail(buf);
        s = buf.toString();
 
        buf = new StringBuffer();
        m = P_ENCODE.matcher(s);
        while (m.find()) {
            final String match = m.group(1);
            final int decimal = Integer.valueOf(match, 16).intValue();
            m.appendReplacement(buf, Matcher.quoteReplacement(chr(decimal)));
        }
        m.appendTail(buf);
        s = buf.toString();
 
        s = validateEntities(s);
        return s;
    }
 
    private String validateEntities(final String s) {
        StringBuffer buf = new StringBuffer();
 
        // validate entities throughout the string
        Matcher m = P_VALID_ENTITIES.matcher(s);
        while (m.find()) {
            final String one = m.group(1); //([^&;]*)
            final String two = m.group(2); //(?=(;|&|$))
            m.appendReplacement(buf, Matcher.quoteReplacement(checkEntity(one, two)));
        }
        m.appendTail(buf);
 
        return encodeQuotes(buf.toString());
    }
 
    private String encodeQuotes(final String s){
        if(encodeQuotes){
            StringBuffer buf = new StringBuffer();
            Matcher m = P_VALID_QUOTES.matcher(s);
            while (m.find()) {
                final String one = m.group(1); //(>|^)
                final String two = m.group(2); //([^<]+?)
                final String three = m.group(3); //(<|$)
                m.appendReplacement(buf, Matcher.quoteReplacement(one + regexReplace(P_QUOTE, "&quot;", two) + three));
            }
            m.appendTail(buf);
            return buf.toString();
        }else{
            return s;
        }
    }
 
    private String checkEntity(final String preamble, final String term) {
 
        return ";".equals(term) && isValidEntity(preamble)
                ? '&' + preamble
                : "&amp;" + preamble;
    }
 
    private boolean isValidEntity(final String entity) {
        return inArray(entity, vAllowedEntities);
    }
 
    private static boolean inArray(final String s, final String[] array) {
        for (String item : array) {
            if (item != null && item.equals(s)) {
                return true;
            }
        }
        return false;
    }
 
    private boolean allowed(final String name) {
        return (vAllowed.isEmpty() || vAllowed.containsKey(name)) && !inArray(name, vDisallowed);
    }
 
    private boolean allowedAttribute(final String name, final String paramName) {
        return allowed(name) && (vAllowed.isEmpty() || vAllowed.get(name).contains(paramName));
    }
}

4)启动类注册过滤器

@ServletComponentScan(basePackages = {"com.chinacreator.c2.filter"})

2、解决sql注入漏洞

package com.chinacreator.c2.filter.sql;

import java.io.IOException;
import java.util.ArrayList;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;

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.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.commons.lang.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.core.annotation.Order;
import org.springframework.http.HttpStatus;

import com.alibaba.fastjson.JSON;

@WebFilter(filterName = "SQLFilter", urlPatterns = "/*")
@Order(1)
public class SQLFilter implements Filter {

	public static Logger log = LoggerFactory.getLogger(SQLFilter.class);

	private static final String SQL_REG_EXP = ".*(\\b(select|insert|into|update|delete|from|where|and|or|trancate" +
		      "|drop|execute|like|grant|use|union|order|by)\\b).*";
	
	@Override
	public void destroy() {
		// TODO Auto-generated method stub
	}

	@Override
	public void doFilter(ServletRequest request, ServletResponse res, FilterChain chain)
			throws IOException, ServletException {
		HttpServletRequest req = (HttpServletRequest) request;
	    Map<String, Object> parameterMap = new HashMap<>();
	    parameterMap =getParameterMap(parameterMap, req);
	    // 正则校验是否有SQL关键字
	    for (Entry<String, Object> entry : parameterMap.entrySet()) {
	        Object value = entry.getValue();
	        if (value != null) {
	            boolean isValid = isSqlInject(value.toString(), res);
	            if (!isValid) {
	                return;
	            }
	        }
	    }
		chain.doFilter(req, res);
	}

	@Override
	public void init(FilterConfig filterConfig) throws ServletException {
		// TODO Auto-generated method stub
	}

	private Map<String, Object> getParameterMap(Map<String, Object> paramMap, HttpServletRequest request) {
	    // 1.POST请求获取参数
	    if ("POST".equals(request.getMethod().toUpperCase())) {
	    	
	    } else {
	    	Enumeration<?> params = request.getParameterNames();
			String paramN = null;
			while (params.hasMoreElements()) {
				paramN = (String) params.nextElement();
				String paramValue = request.getParameter(paramN);
				paramMap.put(paramN, paramValue);
			}
	    }
	    return paramMap;
	  }
	  private boolean isSqlInject(String value, ServletResponse servletResponse) throws IOException {
	    if (null != value) {
	    	if(value.toLowerCase().matches(SQL_REG_EXP) || checkSQLInject(value)) {
	    		log.info("入参中有非法字符: " + value);
	    		HttpServletResponse response = (HttpServletResponse) servletResponse;
	    		Map<String, String> responseMap = new HashMap<>();
	    		// 匹配到非法字符,立即返回
	    		responseMap.put("code", "999");
	    		responseMap.put("message","入参中有非法字符");
	    		response.setContentType("application/json;charset=UTF-8");
	    		response.setStatus(HttpStatus.OK.value());
	    		response.getWriter().write(JSON.toJSONString(responseMap));
	    		response.getWriter().flush();
	    		response.getWriter().close();
	    		return false;
	    	}
	    }
	    
	    return true;
	  }

	/**
	 * 
	 * 检查是否存在非法字符,防止js脚本注入
	 * 
	 * @param str
	 *            被检查的字符串
	 * @return ture-字符串中存在非法字符,false-不存在非法字符
	 */

	public boolean checkSQLInject(String str) {
		if (StringUtils.isEmpty(str)) {
			return false;// 如果传入空串则认为不存在非法字符
		}
		List<String> blackNameList=new ArrayList<String>();
		blackNameList.add("script");
		blackNameList.add("mid");
		blackNameList.add("master");
		blackNameList.add("truncate");
		/*blackNameList.add("insert");
		blackNameList.add("select");
		blackNameList.add("delete");
		blackNameList.add("update");*/
		blackNameList.add("iframe");
		blackNameList.add("referer");
		blackNameList.add("onreadystatechange");
		blackNameList.add("alert");
		blackNameList.add("atestu");
		blackNameList.add("xss");
		blackNameList.add("svg");

		blackNameList.add("confirm");
		blackNameList.add("prompt");
		blackNameList.add("onload");
		blackNameList.add("onmouseover");
		blackNameList.add("sleep");
		blackNameList.add("remove");
		blackNameList.add("onfocus");
		blackNameList.add("onerror");
		blackNameList.add("<");
		blackNameList.add(">");
		blackNameList.add("(");
		blackNameList.add(")");
		blackNameList.add("'");
		blackNameList.add(";");
		/*blackNameList.add(",");*/
		blackNameList.add("\\(");
		blackNameList.add("eval\\\\((.*)\\\\)");
		blackNameList.add("%3C");
		blackNameList.add("%3");
		blackNameList.add("%3C/");
		blackNameList.add("%3E");
		blackNameList.add("%22%3E%3C");
		blackNameList.add("%2e%2e");
		blackNameList.add("win.ini");
		blackNameList.add("boot.ini");
		blackNameList.add("[\\\\\\\"\\\\\\'][\\\\s]*javascript:(.*)[\\\\\\\"\\\\\\']");
		
		// 判断黑名单 
		str = str.toLowerCase(); // sql不区分大小写
if(str.contains("{") && str.contains("}")) {
			return false;
		}
		for(String blackString: blackNameList) {
			if(str.indexOf(blackString) > -1) {
				log.info("参数中含有黑名单的字符:" + blackString);
				return true;
			}
		}
		/*if (blackNameList.contains(str)) {
			log.info("sql不区分大小写:" + str);
				return true;
		}*/
		return false;
	}

}
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