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Diffstat (limited to 'src/service')
| -rw-r--r-- | src/service/sanitize.js | 381 |
1 files changed, 381 insertions, 0 deletions
diff --git a/src/service/sanitize.js b/src/service/sanitize.js new file mode 100644 index 00000000..0d5c74af --- /dev/null +++ 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><div ng:bind-html="snippet"><br/></div></pre> + </td> + <td> + <div ng:bind-html="snippet"></div> + </td> + </tr> + <tr id="escaped-html"> + <td>no filter</td> + <td><pre><div ng:bind-="snippet"><br/></div></pre></td> + <td><div ng:bind="snippet"></div></td> + </tr> + <tr id="html-unsafe-filter"> + <td>unsafe html filter</td> + <td><pre><div ng:bind-html-unsafe="snippet"><br/></div></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("<p style=\"color:blue\">an html\n" + + "<em onmouseover=\"this.textContent='PWN3D!'\">click here</em>\n" + + "snippet</p>"); + }); + + 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 <b>text</b>"); + 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,"<"); + 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, '&'). + replace(NON_ALPHANUMERIC_REGEXP, function(value){ + return '&#' + value.charCodeAt(0) + ';'; + }). + replace(/</g, '<'). + replace(/>/g, '>'); +} + +/** + * 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)); + } + } + }; +} |