From 3c4fee1db116c11d4f04727cfe076d7c94daeaf2 Mon Sep 17 00:00:00 2001
From: yanzhaofeige <yanzhaofeige@qq.com>
Date: Mon, 30 Sep 2024 12:10:57 +0800
Subject: [PATCH] init
---
cpzidc-common/src/main/java/com/odcc/cpzidc/common/utils/html/HTMLFilter.java | 570 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 570 insertions(+), 0 deletions(-)
diff --git a/cpzidc-common/src/main/java/com/odcc/cpzidc/common/utils/html/HTMLFilter.java b/cpzidc-common/src/main/java/com/odcc/cpzidc/common/utils/html/HTMLFilter.java
new file mode 100644
index 0000000..deec92a
--- /dev/null
+++ b/cpzidc-common/src/main/java/com/odcc/cpzidc/common/utils/html/HTMLFilter.java
@@ -0,0 +1,570 @@
+package com.odcc.cpzidc.common.utils.html;
+
+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.regex.Matcher;
+import java.util.regex.Pattern;
+
+/**
+ * HTML过滤器，用于去除XSS漏洞隐患。
+ *
+ * @author ruoyi
+ */
+public final 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("<>");
+
+ // @xxx could grow large... maybe use sesat's ReferenceMap
+ private static final ConcurrentMap<String, Pattern> P_REMOVE_PAIR_BLANKS = new ConcurrentHashMap<>();
+ private static final ConcurrentMap<String, Pattern> P_REMOVE_SELF_BLANKS = new ConcurrentHashMap<>();
+
+ /**
+ * 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<>();
+
+ /**
+ * 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;
+ /**
+ * 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<>();
+ a_atts.add("href");
+ a_atts.add("target");
+ vAllowed.put("a", a_atts);
+
+ final ArrayList<String> img_atts = new ArrayList<>();
+ 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<>();
+ 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 = false;
+ }
+
+ /**
+ * Map-parameter configurable constructor.
+ *
+ * @param conf map containing configuration. keys match field names.
+ */
+ @SuppressWarnings("unchecked")
+ 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();
+ }
+
+ // ---------------------------------------------------------------
+ // 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, "&", result);
+ result = regexReplace(P_QUOTE, """, result);
+ result = regexReplace(P_LEFT_ARROW, "<", result);
+ result = regexReplace(P_RIGHT_ARROW, ">", 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;
+
+ s = escapeComments(s);
+
+ s = balanceHTML(s);
+
+ s = checkTags(s);
+
+ s = processRemoveBlanks(s);
+
+ // s = validateEntities(s);
+
+ 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);
+ // 不追加结束标签
+ 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, "<$1", s);
+ s = regexReplace(P_STRAY_RIGHT_ARROW, "$1$2><", 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);
+
+ // these get tallied in processTag
+ // (remember to reset before subsequent calls to filter method)
+ final StringBuilder sBuilder = new StringBuilder(buf.toString());
+ for (String key : vTagCounts.keySet())
+ {
+ for (int ii = 0; ii < vTagCounts.get(key); ii++)
+ {
+ sBuilder.append("</").append(key).append(">");
+ }
+ }
+ s = sBuilder.toString();
+
+ 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))
+ {
+ final StringBuilder params = new StringBuilder();
+
+ final Matcher m2 = P_QUOTED_ATTRIBUTES.matcher(body);
+ final Matcher m3 = P_UNQUOTED_ATTRIBUTES.matcher(body);
+ final List<String> paramNames = new ArrayList<>();
+ final List<String> paramValues = new ArrayList<>();
+ 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.append(' ').append(paramName).append("=\\\"").append(paramValue).append("\\\"");
+ }
+ }
+
+ 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);
+ if (s.startsWith("#//"))
+ {
+ s = "#" + s.substring(3);
+ }
+ }
+ }
+
+ 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); // (<|$)
+ // 不替换双引号为"，防止json格式无效 regexReplace(P_QUOTE, """, two)
+ m.appendReplacement(buf, Matcher.quoteReplacement(one + 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 : "&" + 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));
+ }
+}
\ No newline at end of file
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