refactor(sanitizer): turn sanitizer into a service

1 files changed, 381 insertions, 0 deletions

diff --git a/src/service/sanitize.js b/src/service/sanitize.js
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+++ b/src/service/sanitize.js
@@ -0,0 +1,381 @@
+'use strict';
+
+/*
+ * HTML Parser By Misko Hevery (misko@hevery.com)
+ * based on:  HTML Parser By John Resig (ejohn.org)
+ * Original code by Erik Arvidsson, Mozilla Public License
+ * http://erik.eae.net/simplehtmlparser/simplehtmlparser.js
+ *
+ * // Use like so:
+ * htmlParser(htmlString, {
+ *     start: function(tag, attrs, unary) {},
+ *     end: function(tag) {},
+ *     chars: function(text) {},
+ *     comment: function(text) {}
+ * });
+ *
+ */
+
+
+
+/**
+ * @ngdoc service
+ * @name angular.module.ng.$sanitize
+ * @function
+ *
+ * @description
+ *   The input is sanitized by parsing the html into tokens. All safe tokens (from a whitelist) are
+ *   then serialized back to properly escaped html string. This means that no unsafe input can make
+ *   it into the returned string, however, since our parser is more strict than a typical browser
+ *   parser, it's possible that some obscure input, which would be recognized as valid HTML by a
+ *   browser, won't make it through the sanitizer.
+ *
+ * @param {string} html Html input.
+ * @returns {string} Sanitized html.
+ *
+ * @example
+   <doc:example>
+     <doc:source>
+       <script>
+         function Ctrl() {
+           this.snippet =
+             '<p style="color:blue">an html\n' +
+             '<em onmouseover="this.textContent=\'PWN3D!\'">click here</em>\n' +
+             'snippet</p>';
+         }
+       </script>
+       <div ng:controller="Ctrl">
+          Snippet: <textarea ng:model="snippet" cols="60" rows="3"></textarea>
+           <table>
+             <tr>
+               <td>Filter</td>
+               <td>Source</td>
+               <td>Rendered</td>
+             </tr>
+             <tr id="html-filter">
+               <td>html filter</td>
+               <td>
+                 <pre>&lt;div ng:bind-html="snippet"&gt;<br/>&lt;/div&gt;</pre>
+               </td>
+               <td>
+                 <div ng:bind-html="snippet"></div>
+               </td>
+             </tr>
+             <tr id="escaped-html">
+               <td>no filter</td>
+               <td><pre>&lt;div ng:bind-="snippet"&gt;<br/>&lt;/div&gt;</pre></td>
+               <td><div ng:bind="snippet"></div></td>
+             </tr>
+             <tr id="html-unsafe-filter">
+               <td>unsafe html filter</td>
+               <td><pre>&lt;div ng:bind-html-unsafe="snippet"&gt;<br/>&lt;/div&gt;</pre></td>
+               <td><div ng:bind-html-unsafe="snippet"></div></td>
+             </tr>
+           </table>
+         </div>
+     </doc:source>
+     <doc:scenario>
+       it('should sanitize the html snippet ', function() {
+         expect(using('#html-filter').element('div').html()).
+           toBe('<p>an html\n<em>click here</em>\nsnippet</p>');
+       });
+
+       it('should escape snippet without any filter', function() {
+         expect(using('#escaped-html').element('div').html()).
+           toBe("&lt;p style=\"color:blue\"&gt;an html\n" +
+                "&lt;em onmouseover=\"this.textContent='PWN3D!'\"&gt;click here&lt;/em&gt;\n" +
+                "snippet&lt;/p&gt;");
+       });
+
+       it('should inline raw snippet if filtered as unsafe', function() {
+         expect(using('#html-unsafe-filter').element("div").html()).
+           toBe("<p style=\"color:blue\">an html\n" +
+                "<em onmouseover=\"this.textContent='PWN3D!'\">click here</em>\n" +
+                "snippet</p>");
+       });
+
+       it('should update', function() {
+         input('snippet').enter('new <b>text</b>');
+         expect(using('#html-filter').binding('snippet')).toBe('new <b>text</b>');
+         expect(using('#escaped-html').element('div').html()).toBe("new &lt;b&gt;text&lt;/b&gt;");
+         expect(using('#html-unsafe-filter').binding("snippet")).toBe('new <b>text</b>');
+       });
+     </doc:scenario>
+   </doc:example>
+ */
+
+function $SanitizeProvider() {
+  this.$get = valueFn(function(html) {
+    var buf = [];
+    htmlParser(html, htmlSanitizeWriter(buf));
+    return buf.join('');
+  });
+};
+
+// Regular Expressions for parsing tags and attributes
+var START_TAG_REGEXP = /^<\s*([\w:-]+)((?:\s+[\w:-]+(?:\s*=\s*(?:(?:"[^"]*")|(?:'[^']*')|[^>\s]+))?)*)\s*(\/?)\s*>/,
+  END_TAG_REGEXP = /^<\s*\/\s*([\w:-]+)[^>]*>/,
+  ATTR_REGEXP = /([\w:-]+)(?:\s*=\s*(?:(?:"((?:[^"])*)")|(?:'((?:[^'])*)')|([^>\s]+)))?/g,
+  BEGIN_TAG_REGEXP = /^</,
+  BEGING_END_TAGE_REGEXP = /^<\s*\//,
+  COMMENT_REGEXP = /<!--(.*?)-->/g,
+  CDATA_REGEXP = /<!\[CDATA\[(.*?)]]>/g,
+  URI_REGEXP = /^((ftp|https?):\/\/|mailto:|#)/,
+  NON_ALPHANUMERIC_REGEXP = /([^\#-~| |!])/g; // Match everything outside of normal chars and " (quote character)
+
+
+// Good source of info about elements and attributes
+// http://dev.w3.org/html5/spec/Overview.html#semantics
+// http://simon.html5.org/html-elements
+
+// Safe Void Elements - HTML5
+// http://dev.w3.org/html5/spec/Overview.html#void-elements
+var voidElements = makeMap("area,br,col,hr,img,wbr");
+
+// Elements that you can, intentionally, leave open (and which close themselves)
+// http://dev.w3.org/html5/spec/Overview.html#optional-tags
+var optionalEndTagBlockElements = makeMap("colgroup,dd,dt,li,p,tbody,td,tfoot,th,thead,tr"),
+    optionalEndTagInlineElements = makeMap("rp,rt"),
+    optionalEndTagElements = extend({}, optionalEndTagInlineElements, optionalEndTagBlockElements);
+
+// Safe Block Elements - HTML5
+var blockElements = extend({}, optionalEndTagBlockElements, makeMap("address,article,aside," +
+        "blockquote,caption,center,del,dir,div,dl,figure,figcaption,footer,h1,h2,h3,h4,h5,h6," +
+        "header,hgroup,hr,ins,map,menu,nav,ol,pre,script,section,table,ul"));
+
+// Inline Elements - HTML5
+var inlineElements = extend({}, optionalEndTagInlineElements, makeMap("a,abbr,acronym,b,bdi,bdo," +
+        "big,br,cite,code,del,dfn,em,font,i,img,ins,kbd,label,map,mark,q,ruby,rp,rt,s,samp,small," +
+        "span,strike,strong,sub,sup,time,tt,u,var"));
+
+
+// Special Elements (can contain anything)
+var specialElements = makeMap("script,style");
+
+var validElements = extend({}, voidElements, blockElements, inlineElements, optionalEndTagElements);
+
+//Attributes that have href and hence need to be sanitized
+var uriAttrs = makeMap("background,cite,href,longdesc,src,usemap");
+var validAttrs = extend({}, uriAttrs, makeMap(
+    'abbr,align,alt,axis,bgcolor,border,cellpadding,cellspacing,class,clear,'+
+    'color,cols,colspan,compact,coords,dir,face,headers,height,hreflang,hspace,'+
+    'ismap,lang,language,nohref,nowrap,rel,rev,rows,rowspan,rules,'+
+    'scope,scrolling,shape,span,start,summary,target,title,type,'+
+    'valign,value,vspace,width'));
+
+/**
+ * @example
+ * htmlParser(htmlString, {
+ *     start: function(tag, attrs, unary) {},
+ *     end: function(tag) {},
+ *     chars: function(text) {},
+ *     comment: function(text) {}
+ * });
+ *
+ * @param {string} html string
+ * @param {object} handler
+ */
+function htmlParser( html, handler ) {
+  var index, chars, match, stack = [], last = html;
+  stack.last = function() { return stack[ stack.length - 1 ]; };
+
+  while ( html ) {
+    chars = true;
+
+    // Make sure we're not in a script or style element
+    if ( !stack.last() || !specialElements[ stack.last() ] ) {
+
+      // Comment
+      if ( html.indexOf("<!--") === 0 ) {
+        index = html.indexOf("-->");
+
+        if ( index >= 0 ) {
+          if (handler.comment) handler.comment( html.substring( 4, index ) );
+          html = html.substring( index + 3 );
+          chars = false;
+        }
+
+      // end tag
+      } else if ( BEGING_END_TAGE_REGEXP.test(html) ) {
+        match = html.match( END_TAG_REGEXP );
+
+        if ( match ) {
+          html = html.substring( match[0].length );
+          match[0].replace( END_TAG_REGEXP, parseEndTag );
+          chars = false;
+        }
+
+      // start tag
+      } else if ( BEGIN_TAG_REGEXP.test(html) ) {
+        match = html.match( START_TAG_REGEXP );
+
+        if ( match ) {
+          html = html.substring( match[0].length );
+          match[0].replace( START_TAG_REGEXP, parseStartTag );
+          chars = false;
+        }
+      }
+
+      if ( chars ) {
+        index = html.indexOf("<");
+
+        var text = index < 0 ? html : html.substring( 0, index );
+        html = index < 0 ? "" : html.substring( index );
+
+        if (handler.chars) handler.chars( decodeEntities(text) );
+      }
+
+    } else {
+      html = html.replace(new RegExp("(.*)<\\s*\\/\\s*" + stack.last() + "[^>]*>", 'i'), function(all, text){
+        text = text.
+          replace(COMMENT_REGEXP, "$1").
+          replace(CDATA_REGEXP, "$1");
+
+        if (handler.chars) handler.chars( decodeEntities(text) );
+
+        return "";
+      });
+
+      parseEndTag( "", stack.last() );
+    }
+
+    if ( html == last ) {
+      throw "Parse Error: " + html;
+    }
+    last = html;
+  }
+
+  // Clean up any remaining tags
+  parseEndTag();
+
+  function parseStartTag( tag, tagName, rest, unary ) {
+    tagName = lowercase(tagName);
+    if ( blockElements[ tagName ] ) {
+      while ( stack.last() && inlineElements[ stack.last() ] ) {
+        parseEndTag( "", stack.last() );
+      }
+    }
+
+    if ( optionalEndTagElements[ tagName ] && stack.last() == tagName ) {
+      parseEndTag( "", tagName );
+    }
+
+    unary = voidElements[ tagName ] || !!unary;
+
+    if ( !unary )
+      stack.push( tagName );
+
+    var attrs = {};
+
+    rest.replace(ATTR_REGEXP, function(match, name, doubleQuotedValue, singleQoutedValue, unqoutedValue) {
+      var value = doubleQuotedValue
+        || singleQoutedValue
+        || unqoutedValue
+        || '';
+
+      attrs[name] = decodeEntities(value);
+    });
+    if (handler.start) handler.start( tagName, attrs, unary );
+  }
+
+  function parseEndTag( tag, tagName ) {
+    var pos = 0, i;
+    tagName = lowercase(tagName);
+    if ( tagName )
+      // Find the closest opened tag of the same type
+      for ( pos = stack.length - 1; pos >= 0; pos-- )
+        if ( stack[ pos ] == tagName )
+          break;
+
+    if ( pos >= 0 ) {
+      // Close all the open elements, up the stack
+      for ( i = stack.length - 1; i >= pos; i-- )
+        if (handler.end) handler.end( stack[ i ] );
+
+      // Remove the open elements from the stack
+      stack.length = pos;
+    }
+  }
+}
+
+/**
+ * decodes all entities into regular string
+ * @param value
+ * @returns {string} A string with decoded entities.
+ */
+var hiddenPre=document.createElement("pre");
+function decodeEntities(value) {
+  hiddenPre.innerHTML=value.replace(/</g,"&lt;");
+  return hiddenPre.innerText || hiddenPre.textContent || '';
+}
+
+/**
+ * Escapes all potentially dangerous characters, so that the
+ * resulting string can be safely inserted into attribute or
+ * element text.
+ * @param value
+ * @returns escaped text
+ */
+function encodeEntities(value) {
+  return value.
+    replace(/&/g, '&amp;').
+    replace(NON_ALPHANUMERIC_REGEXP, function(value){
+      return '&#' + value.charCodeAt(0) + ';';
+    }).
+    replace(/</g, '&lt;').
+    replace(/>/g, '&gt;');
+}
+
+/**
+ * create an HTML/XML writer which writes to buffer
+ * @param {Array} buf use buf.jain('') to get out sanitized html string
+ * @returns {object} in the form of {
+ *     start: function(tag, attrs, unary) {},
+ *     end: function(tag) {},
+ *     chars: function(text) {},
+ *     comment: function(text) {}
+ * }
+ */
+function htmlSanitizeWriter(buf){
+  var ignore = false;
+  var out = bind(buf, buf.push);
+  return {
+    start: function(tag, attrs, unary){
+      tag = lowercase(tag);
+      if (!ignore && specialElements[tag]) {
+        ignore = tag;
+      }
+      if (!ignore && validElements[tag] == true) {
+        out('<');
+        out(tag);
+        forEach(attrs, function(value, key){
+          var lkey=lowercase(key);
+          if (validAttrs[lkey]==true && (uriAttrs[lkey]!==true || value.match(URI_REGEXP))) {
+            out(' ');
+            out(key);
+            out('="');
+            out(encodeEntities(value));
+            out('"');
+          }
+        });
+        out(unary ? '/>' : '>');
+      }
+    },
+    end: function(tag){
+        tag = lowercase(tag);
+        if (!ignore && validElements[tag] == true) {
+          out('</');
+          out(tag);
+          out('>');
+        }
+        if (tag == ignore) {
+          ignore = false;
+        }
+      },
+    chars: function(chars){
+        if (!ignore) {
+          out(encodeEntities(chars));
+        }
+      }
+  };
+}