summaryrefslogtreecommitdiff
path: root/xstatic/pkg/angular/data/angular-sanitize.js
blob: 451073f2d662b2d43f8f7dcad102bfe49f57a7dc (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
/**
 * @license AngularJS v1.8.2
 * (c) 2010-2020 Google, Inc. http://angularjs.org
 * License: MIT
 */
(function(window, angular) {'use strict';

/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
 *     Any commits to this file should be reviewed with security in mind.  *
 *   Changes to this file can potentially create security vulnerabilities. *
 *          An approval from 2 Core members with history of modifying      *
 *                         this file is required.                          *
 *                                                                         *
 *  Does the change somehow allow for arbitrary javascript to be executed? *
 *    Or allows for someone to change the prototype of built-in objects?   *
 *     Or gives undesired access to variables likes document or window?    *
 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */

var $sanitizeMinErr = angular.$$minErr('$sanitize');
var bind;
var extend;
var forEach;
var isArray;
var isDefined;
var lowercase;
var noop;
var nodeContains;
var htmlParser;
var htmlSanitizeWriter;

/**
 * @ngdoc module
 * @name ngSanitize
 * @description
 *
 * The `ngSanitize` module provides functionality to sanitize HTML.
 *
 * See {@link ngSanitize.$sanitize `$sanitize`} for usage.
 */

/**
 * @ngdoc service
 * @name $sanitize
 * @kind function
 *
 * @description
 *   Sanitizes an html string by stripping all potentially dangerous tokens.
 *
 *   The input is sanitized by parsing the HTML into tokens. All safe tokens (from a trusted URI list) are
 *   then serialized back to a properly escaped HTML string. This means that no unsafe input can make
 *   it into the returned string.
 *
 *   The trusted URIs for URL sanitization of attribute values is configured using the functions
 *   `aHrefSanitizationTrustedUrlList` and `imgSrcSanitizationTrustedUrlList` of {@link $compileProvider}.
 *
 *   The input may also contain SVG markup if this is enabled via {@link $sanitizeProvider}.
 *
 * @param {string} html HTML input.
 * @returns {string} Sanitized HTML.
 *
 * @example
   <example module="sanitizeExample" deps="angular-sanitize.js" name="sanitize-service">
   <file name="index.html">
     <script>
         angular.module('sanitizeExample', ['ngSanitize'])
           .controller('ExampleController', ['$scope', '$sce', function($scope, $sce) {
             $scope.snippet =
               '<p style="color:blue">an html\n' +
               '<em onmouseover="this.textContent=\'PWN3D!\'">click here</em>\n' +
               'snippet</p>';
             $scope.deliberatelyTrustDangerousSnippet = function() {
               return $sce.trustAsHtml($scope.snippet);
             };
           }]);
     </script>
     <div ng-controller="ExampleController">
        Snippet: <textarea ng-model="snippet" cols="60" rows="3"></textarea>
       <table>
         <tr>
           <td>Directive</td>
           <td>How</td>
           <td>Source</td>
           <td>Rendered</td>
         </tr>
         <tr id="bind-html-with-sanitize">
           <td>ng-bind-html</td>
           <td>Automatically uses $sanitize</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="bind-html-with-trust">
           <td>ng-bind-html</td>
           <td>Bypass $sanitize by explicitly trusting the dangerous value</td>
           <td>
           <pre>&lt;div ng-bind-html="deliberatelyTrustDangerousSnippet()"&gt;
&lt;/div&gt;</pre>
           </td>
           <td><div ng-bind-html="deliberatelyTrustDangerousSnippet()"></div></td>
         </tr>
         <tr id="bind-default">
           <td>ng-bind</td>
           <td>Automatically escapes</td>
           <td><pre>&lt;div ng-bind="snippet"&gt;<br/>&lt;/div&gt;</pre></td>
           <td><div ng-bind="snippet"></div></td>
         </tr>
       </table>
       </div>
   </file>
   <file name="protractor.js" type="protractor">
     it('should sanitize the html snippet by default', function() {
       expect(element(by.css('#bind-html-with-sanitize div')).getAttribute('innerHTML')).
         toBe('<p>an html\n<em>click here</em>\nsnippet</p>');
     });

     it('should inline raw snippet if bound to a trusted value', function() {
       expect(element(by.css('#bind-html-with-trust div')).getAttribute('innerHTML')).
         toBe("<p style=\"color:blue\">an html\n" +
              "<em onmouseover=\"this.textContent='PWN3D!'\">click here</em>\n" +
              "snippet</p>");
     });

     it('should escape snippet without any filter', function() {
       expect(element(by.css('#bind-default div')).getAttribute('innerHTML')).
         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 update', function() {
       element(by.model('snippet')).clear();
       element(by.model('snippet')).sendKeys('new <b onclick="alert(1)">text</b>');
       expect(element(by.css('#bind-html-with-sanitize div')).getAttribute('innerHTML')).
         toBe('new <b>text</b>');
       expect(element(by.css('#bind-html-with-trust div')).getAttribute('innerHTML')).toBe(
         'new <b onclick="alert(1)">text</b>');
       expect(element(by.css('#bind-default div')).getAttribute('innerHTML')).toBe(
         "new &lt;b onclick=\"alert(1)\"&gt;text&lt;/b&gt;");
     });
   </file>
   </example>
 */


/**
 * @ngdoc provider
 * @name $sanitizeProvider
 * @this
 *
 * @description
 * Creates and configures {@link $sanitize} instance.
 */
function $SanitizeProvider() {
  var hasBeenInstantiated = false;
  var svgEnabled = false;

  this.$get = ['$$sanitizeUri', function($$sanitizeUri) {
    hasBeenInstantiated = true;
    if (svgEnabled) {
      extend(validElements, svgElements);
    }
    return function(html) {
      var buf = [];
      htmlParser(html, htmlSanitizeWriter(buf, function(uri, isImage) {
        return !/^unsafe:/.test($$sanitizeUri(uri, isImage));
      }));
      return buf.join('');
    };
  }];


  /**
   * @ngdoc method
   * @name $sanitizeProvider#enableSvg
   * @kind function
   *
   * @description
   * Enables a subset of svg to be supported by the sanitizer.
   *
   * <div class="alert alert-warning">
   *   <p>By enabling this setting without taking other precautions, you might expose your
   *   application to click-hijacking attacks. In these attacks, sanitized svg elements could be positioned
   *   outside of the containing element and be rendered over other elements on the page (e.g. a login
   *   link). Such behavior can then result in phishing incidents.</p>
   *
   *   <p>To protect against these, explicitly setup `overflow: hidden` css rule for all potential svg
   *   tags within the sanitized content:</p>
   *
   *   <br>
   *
   *   <pre><code>
   *   .rootOfTheIncludedContent svg {
   *     overflow: hidden !important;
   *   }
   *   </code></pre>
   * </div>
   *
   * @param {boolean=} flag Enable or disable SVG support in the sanitizer.
   * @returns {boolean|$sanitizeProvider} Returns the currently configured value if called
   *    without an argument or self for chaining otherwise.
   */
  this.enableSvg = function(enableSvg) {
    if (isDefined(enableSvg)) {
      svgEnabled = enableSvg;
      return this;
    } else {
      return svgEnabled;
    }
  };


  /**
   * @ngdoc method
   * @name $sanitizeProvider#addValidElements
   * @kind function
   *
   * @description
   * Extends the built-in lists of valid HTML/SVG elements, i.e. elements that are considered safe
   * and are not stripped off during sanitization. You can extend the following lists of elements:
   *
   * - `htmlElements`: A list of elements (tag names) to extend the current list of safe HTML
   *   elements. HTML elements considered safe will not be removed during sanitization. All other
   *   elements will be stripped off.
   *
   * - `htmlVoidElements`: This is similar to `htmlElements`, but marks the elements as
   *   "void elements" (similar to HTML
   *   [void elements](https://rawgit.com/w3c/html/html5.1-2/single-page.html#void-elements)). These
   *   elements have no end tag and cannot have content.
   *
   * - `svgElements`: This is similar to `htmlElements`, but for SVG elements. This list is only
   *   taken into account if SVG is {@link ngSanitize.$sanitizeProvider#enableSvg enabled} for
   *   `$sanitize`.
   *
   * <div class="alert alert-info">
   *   This method must be called during the {@link angular.Module#config config} phase. Once the
   *   `$sanitize` service has been instantiated, this method has no effect.
   * </div>
   *
   * <div class="alert alert-warning">
   *   Keep in mind that extending the built-in lists of elements may expose your app to XSS or
   *   other vulnerabilities. Be very mindful of the elements you add.
   * </div>
   *
   * @param {Array<String>|Object} elements - A list of valid HTML elements or an object with one or
   *   more of the following properties:
   *   - **htmlElements** - `{Array<String>}` - A list of elements to extend the current list of
   *     HTML elements.
   *   - **htmlVoidElements** - `{Array<String>}` - A list of elements to extend the current list of
   *     void HTML elements; i.e. elements that do not have an end tag.
   *   - **svgElements** - `{Array<String>}` - A list of elements to extend the current list of SVG
   *     elements. The list of SVG elements is only taken into account if SVG is
   *     {@link ngSanitize.$sanitizeProvider#enableSvg enabled} for `$sanitize`.
   *
   * Passing an array (`[...]`) is equivalent to passing `{htmlElements: [...]}`.
   *
   * @return {$sanitizeProvider} Returns self for chaining.
   */
  this.addValidElements = function(elements) {
    if (!hasBeenInstantiated) {
      if (isArray(elements)) {
        elements = {htmlElements: elements};
      }

      addElementsTo(svgElements, elements.svgElements);
      addElementsTo(voidElements, elements.htmlVoidElements);
      addElementsTo(validElements, elements.htmlVoidElements);
      addElementsTo(validElements, elements.htmlElements);
    }

    return this;
  };


  /**
   * @ngdoc method
   * @name $sanitizeProvider#addValidAttrs
   * @kind function
   *
   * @description
   * Extends the built-in list of valid attributes, i.e. attributes that are considered safe and are
   * not stripped off during sanitization.
   *
   * **Note**:
   * The new attributes will not be treated as URI attributes, which means their values will not be
   * sanitized as URIs using `$compileProvider`'s
   * {@link ng.$compileProvider#aHrefSanitizationTrustedUrlList aHrefSanitizationTrustedUrlList} and
   * {@link ng.$compileProvider#imgSrcSanitizationTrustedUrlList imgSrcSanitizationTrustedUrlList}.
   *
   * <div class="alert alert-info">
   *   This method must be called during the {@link angular.Module#config config} phase. Once the
   *   `$sanitize` service has been instantiated, this method has no effect.
   * </div>
   *
   * <div class="alert alert-warning">
   *   Keep in mind that extending the built-in list of attributes may expose your app to XSS or
   *   other vulnerabilities. Be very mindful of the attributes you add.
   * </div>
   *
   * @param {Array<String>} attrs - A list of valid attributes.
   *
   * @returns {$sanitizeProvider} Returns self for chaining.
   */
  this.addValidAttrs = function(attrs) {
    if (!hasBeenInstantiated) {
      extend(validAttrs, arrayToMap(attrs, true));
    }
    return this;
  };

  //////////////////////////////////////////////////////////////////////////////////////////////////
  // Private stuff
  //////////////////////////////////////////////////////////////////////////////////////////////////

  bind = angular.bind;
  extend = angular.extend;
  forEach = angular.forEach;
  isArray = angular.isArray;
  isDefined = angular.isDefined;
  lowercase = angular.$$lowercase;
  noop = angular.noop;

  htmlParser = htmlParserImpl;
  htmlSanitizeWriter = htmlSanitizeWriterImpl;

  nodeContains = window.Node.prototype.contains || /** @this */ function(arg) {
    // eslint-disable-next-line no-bitwise
    return !!(this.compareDocumentPosition(arg) & 16);
  };

  // Regular Expressions for parsing tags and attributes
  var SURROGATE_PAIR_REGEXP = /[\uD800-\uDBFF][\uDC00-\uDFFF]/g,
    // Match everything outside of normal chars and " (quote character)
    NON_ALPHANUMERIC_REGEXP = /([^#-~ |!])/g;


  // 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 = stringToMap('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 = stringToMap('colgroup,dd,dt,li,p,tbody,td,tfoot,th,thead,tr'),
      optionalEndTagInlineElements = stringToMap('rp,rt'),
      optionalEndTagElements = extend({},
                                              optionalEndTagInlineElements,
                                              optionalEndTagBlockElements);

  // Safe Block Elements - HTML5
  var blockElements = extend({}, optionalEndTagBlockElements, stringToMap('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,section,table,ul'));

  // Inline Elements - HTML5
  var inlineElements = extend({}, optionalEndTagInlineElements, stringToMap('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'));

  // SVG Elements
  // https://wiki.whatwg.org/wiki/Sanitization_rules#svg_Elements
  // Note: the elements animate,animateColor,animateMotion,animateTransform,set are intentionally omitted.
  // They can potentially allow for arbitrary javascript to be executed. See #11290
  var svgElements = stringToMap('circle,defs,desc,ellipse,font-face,font-face-name,font-face-src,g,glyph,' +
          'hkern,image,linearGradient,line,marker,metadata,missing-glyph,mpath,path,polygon,polyline,' +
          'radialGradient,rect,stop,svg,switch,text,title,tspan');

  // Blocked Elements (will be stripped)
  var blockedElements = stringToMap('script,style');

  var validElements = extend({},
                                     voidElements,
                                     blockElements,
                                     inlineElements,
                                     optionalEndTagElements);

  //Attributes that have href and hence need to be sanitized
  var uriAttrs = stringToMap('background,cite,href,longdesc,src,xlink:href,xml:base');

  var htmlAttrs = stringToMap('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,size,span,start,summary,tabindex,target,title,type,' +
      'valign,value,vspace,width');

  // SVG attributes (without "id" and "name" attributes)
  // https://wiki.whatwg.org/wiki/Sanitization_rules#svg_Attributes
  var svgAttrs = stringToMap('accent-height,accumulate,additive,alphabetic,arabic-form,ascent,' +
      'baseProfile,bbox,begin,by,calcMode,cap-height,class,color,color-rendering,content,' +
      'cx,cy,d,dx,dy,descent,display,dur,end,fill,fill-rule,font-family,font-size,font-stretch,' +
      'font-style,font-variant,font-weight,from,fx,fy,g1,g2,glyph-name,gradientUnits,hanging,' +
      'height,horiz-adv-x,horiz-origin-x,ideographic,k,keyPoints,keySplines,keyTimes,lang,' +
      'marker-end,marker-mid,marker-start,markerHeight,markerUnits,markerWidth,mathematical,' +
      'max,min,offset,opacity,orient,origin,overline-position,overline-thickness,panose-1,' +
      'path,pathLength,points,preserveAspectRatio,r,refX,refY,repeatCount,repeatDur,' +
      'requiredExtensions,requiredFeatures,restart,rotate,rx,ry,slope,stemh,stemv,stop-color,' +
      'stop-opacity,strikethrough-position,strikethrough-thickness,stroke,stroke-dasharray,' +
      'stroke-dashoffset,stroke-linecap,stroke-linejoin,stroke-miterlimit,stroke-opacity,' +
      'stroke-width,systemLanguage,target,text-anchor,to,transform,type,u1,u2,underline-position,' +
      'underline-thickness,unicode,unicode-range,units-per-em,values,version,viewBox,visibility,' +
      'width,widths,x,x-height,x1,x2,xlink:actuate,xlink:arcrole,xlink:role,xlink:show,xlink:title,' +
      'xlink:type,xml:base,xml:lang,xml:space,xmlns,xmlns:xlink,y,y1,y2,zoomAndPan', true);

  var validAttrs = extend({},
                                  uriAttrs,
                                  svgAttrs,
                                  htmlAttrs);

  function stringToMap(str, lowercaseKeys) {
    return arrayToMap(str.split(','), lowercaseKeys);
  }

  function arrayToMap(items, lowercaseKeys) {
    var obj = {}, i;
    for (i = 0; i < items.length; i++) {
      obj[lowercaseKeys ? lowercase(items[i]) : items[i]] = true;
    }
    return obj;
  }

  function addElementsTo(elementsMap, newElements) {
    if (newElements && newElements.length) {
      extend(elementsMap, arrayToMap(newElements));
    }
  }

  /**
   * Create an inert document that contains the dirty HTML that needs sanitizing.
   * We use the DOMParser API by default and fall back to createHTMLDocument if DOMParser is not
   * available.
   */
  var getInertBodyElement /* function(html: string): HTMLBodyElement */ = (function(window, document) {
    if (isDOMParserAvailable()) {
      return getInertBodyElement_DOMParser;
    }

    if (!document || !document.implementation) {
      throw $sanitizeMinErr('noinert', 'Can\'t create an inert html document');
    }
    var inertDocument = document.implementation.createHTMLDocument('inert');
    var inertBodyElement = (inertDocument.documentElement || inertDocument.getDocumentElement()).querySelector('body');
    return getInertBodyElement_InertDocument;

    function isDOMParserAvailable() {
      try {
        return !!getInertBodyElement_DOMParser('');
      } catch (e) {
        return false;
      }
    }

    function getInertBodyElement_DOMParser(html) {
      // We add this dummy element to ensure that the rest of the content is parsed as expected
      // e.g. leading whitespace is maintained and tags like `<meta>` do not get hoisted to the `<head>` tag.
      html = '<remove></remove>' + html;
      try {
        var body = new window.DOMParser().parseFromString(html, 'text/html').body;
        body.firstChild.remove();
        return body;
      } catch (e) {
        return undefined;
      }
    }

    function getInertBodyElement_InertDocument(html) {
      inertBodyElement.innerHTML = html;

      // Support: IE 9-11 only
      // strip custom-namespaced attributes on IE<=11
      if (document.documentMode) {
        stripCustomNsAttrs(inertBodyElement);
      }

      return inertBodyElement;
    }
  })(window, window.document);

  /**
   * @example
   * htmlParser(htmlString, {
   *     start: function(tag, attrs) {},
   *     end: function(tag) {},
   *     chars: function(text) {},
   *     comment: function(text) {}
   * });
   *
   * @param {string} html string
   * @param {object} handler
   */
  function htmlParserImpl(html, handler) {
    if (html === null || html === undefined) {
      html = '';
    } else if (typeof html !== 'string') {
      html = '' + html;
    }

    var inertBodyElement = getInertBodyElement(html);
    if (!inertBodyElement) return '';

    //mXSS protection
    var mXSSAttempts = 5;
    do {
      if (mXSSAttempts === 0) {
        throw $sanitizeMinErr('uinput', 'Failed to sanitize html because the input is unstable');
      }
      mXSSAttempts--;

      // trigger mXSS if it is going to happen by reading and writing the innerHTML
      html = inertBodyElement.innerHTML;
      inertBodyElement = getInertBodyElement(html);
    } while (html !== inertBodyElement.innerHTML);

    var node = inertBodyElement.firstChild;
    while (node) {
      switch (node.nodeType) {
        case 1: // ELEMENT_NODE
          handler.start(node.nodeName.toLowerCase(), attrToMap(node.attributes));
          break;
        case 3: // TEXT NODE
          handler.chars(node.textContent);
          break;
      }

      var nextNode;
      if (!(nextNode = node.firstChild)) {
        if (node.nodeType === 1) {
          handler.end(node.nodeName.toLowerCase());
        }
        nextNode = getNonDescendant('nextSibling', node);
        if (!nextNode) {
          while (nextNode == null) {
            node = getNonDescendant('parentNode', node);
            if (node === inertBodyElement) break;
            nextNode = getNonDescendant('nextSibling', node);
            if (node.nodeType === 1) {
              handler.end(node.nodeName.toLowerCase());
            }
          }
        }
      }
      node = nextNode;
    }

    while ((node = inertBodyElement.firstChild)) {
      inertBodyElement.removeChild(node);
    }
  }

  function attrToMap(attrs) {
    var map = {};
    for (var i = 0, ii = attrs.length; i < ii; i++) {
      var attr = attrs[i];
      map[attr.name] = attr.value;
    }
    return map;
  }


  /**
   * Escapes all potentially dangerous characters, so that the
   * resulting string can be safely inserted into attribute or
   * element text.
   * @param value
   * @returns {string} escaped text
   */
  function encodeEntities(value) {
    return value.
      replace(/&/g, '&amp;').
      replace(SURROGATE_PAIR_REGEXP, function(value) {
        var hi = value.charCodeAt(0);
        var low = value.charCodeAt(1);
        return '&#' + (((hi - 0xD800) * 0x400) + (low - 0xDC00) + 0x10000) + ';';
      }).
      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.join('') to get out sanitized html string
   * @returns {object} in the form of {
   *     start: function(tag, attrs) {},
   *     end: function(tag) {},
   *     chars: function(text) {},
   *     comment: function(text) {}
   * }
   */
  function htmlSanitizeWriterImpl(buf, uriValidator) {
    var ignoreCurrentElement = false;
    var out = bind(buf, buf.push);
    return {
      start: function(tag, attrs) {
        tag = lowercase(tag);
        if (!ignoreCurrentElement && blockedElements[tag]) {
          ignoreCurrentElement = tag;
        }
        if (!ignoreCurrentElement && validElements[tag] === true) {
          out('<');
          out(tag);
          forEach(attrs, function(value, key) {
            var lkey = lowercase(key);
            var isImage = (tag === 'img' && lkey === 'src') || (lkey === 'background');
            if (validAttrs[lkey] === true &&
              (uriAttrs[lkey] !== true || uriValidator(value, isImage))) {
              out(' ');
              out(key);
              out('="');
              out(encodeEntities(value));
              out('"');
            }
          });
          out('>');
        }
      },
      end: function(tag) {
        tag = lowercase(tag);
        if (!ignoreCurrentElement && validElements[tag] === true && voidElements[tag] !== true) {
          out('</');
          out(tag);
          out('>');
        }
        // eslint-disable-next-line eqeqeq
        if (tag == ignoreCurrentElement) {
          ignoreCurrentElement = false;
        }
      },
      chars: function(chars) {
        if (!ignoreCurrentElement) {
          out(encodeEntities(chars));
        }
      }
    };
  }


  /**
   * When IE9-11 comes across an unknown namespaced attribute e.g. 'xlink:foo' it adds 'xmlns:ns1' attribute to declare
   * ns1 namespace and prefixes the attribute with 'ns1' (e.g. 'ns1:xlink:foo'). This is undesirable since we don't want
   * to allow any of these custom attributes. This method strips them all.
   *
   * @param node Root element to process
   */
  function stripCustomNsAttrs(node) {
    while (node) {
      if (node.nodeType === window.Node.ELEMENT_NODE) {
        var attrs = node.attributes;
        for (var i = 0, l = attrs.length; i < l; i++) {
          var attrNode = attrs[i];
          var attrName = attrNode.name.toLowerCase();
          if (attrName === 'xmlns:ns1' || attrName.lastIndexOf('ns1:', 0) === 0) {
            node.removeAttributeNode(attrNode);
            i--;
            l--;
          }
        }
      }

      var nextNode = node.firstChild;
      if (nextNode) {
        stripCustomNsAttrs(nextNode);
      }

      node = getNonDescendant('nextSibling', node);
    }
  }

  function getNonDescendant(propName, node) {
    // An element is clobbered if its `propName` property points to one of its descendants
    var nextNode = node[propName];
    if (nextNode && nodeContains.call(node, nextNode)) {
      throw $sanitizeMinErr('elclob', 'Failed to sanitize html because the element is clobbered: {0}', node.outerHTML || node.outerText);
    }
    return nextNode;
  }
}

function sanitizeText(chars) {
  var buf = [];
  var writer = htmlSanitizeWriter(buf, noop);
  writer.chars(chars);
  return buf.join('');
}


// define ngSanitize module and register $sanitize service
angular.module('ngSanitize', [])
  .provider('$sanitize', $SanitizeProvider)
  .info({ angularVersion: '"1.8.2"' });

/**
 * @ngdoc filter
 * @name linky
 * @kind function
 *
 * @description
 * Finds links in text input and turns them into html links. Supports `http/https/ftp/sftp/mailto` and
 * plain email address links.
 *
 * Requires the {@link ngSanitize `ngSanitize`} module to be installed.
 *
 * @param {string} text Input text.
 * @param {string} [target] Window (`_blank|_self|_parent|_top`) or named frame to open links in.
 * @param {object|function(url)} [attributes] Add custom attributes to the link element.
 *
 *    Can be one of:
 *
 *    - `object`: A map of attributes
 *    - `function`: Takes the url as a parameter and returns a map of attributes
 *
 *    If the map of attributes contains a value for `target`, it overrides the value of
 *    the target parameter.
 *
 *
 * @returns {string} Html-linkified and {@link $sanitize sanitized} text.
 *
 * @usage
   <span ng-bind-html="linky_expression | linky"></span>
 *
 * @example
   <example module="linkyExample" deps="angular-sanitize.js" name="linky-filter">
     <file name="index.html">
       <div ng-controller="ExampleController">
       Snippet: <textarea ng-model="snippet" cols="60" rows="3"></textarea>
       <table>
         <tr>
           <th>Filter</th>
           <th>Source</th>
           <th>Rendered</th>
         </tr>
         <tr id="linky-filter">
           <td>linky filter</td>
           <td>
             <pre>&lt;div ng-bind-html="snippet | linky"&gt;<br>&lt;/div&gt;</pre>
           </td>
           <td>
             <div ng-bind-html="snippet | linky"></div>
           </td>
         </tr>
         <tr id="linky-target">
          <td>linky target</td>
          <td>
            <pre>&lt;div ng-bind-html="snippetWithSingleURL | linky:'_blank'"&gt;<br>&lt;/div&gt;</pre>
          </td>
          <td>
            <div ng-bind-html="snippetWithSingleURL | linky:'_blank'"></div>
          </td>
         </tr>
         <tr id="linky-custom-attributes">
          <td>linky custom attributes</td>
          <td>
            <pre>&lt;div ng-bind-html="snippetWithSingleURL | linky:'_self':{rel: 'nofollow'}"&gt;<br>&lt;/div&gt;</pre>
          </td>
          <td>
            <div ng-bind-html="snippetWithSingleURL | linky:'_self':{rel: 'nofollow'}"></div>
          </td>
         </tr>
         <tr id="escaped-html">
           <td>no filter</td>
           <td><pre>&lt;div ng-bind="snippet"&gt;<br>&lt;/div&gt;</pre></td>
           <td><div ng-bind="snippet"></div></td>
         </tr>
       </table>
     </file>
     <file name="script.js">
       angular.module('linkyExample', ['ngSanitize'])
         .controller('ExampleController', ['$scope', function($scope) {
           $scope.snippet =
             'Pretty text with some links:\n' +
             'http://angularjs.org/,\n' +
             'mailto:us@somewhere.org,\n' +
             'another@somewhere.org,\n' +
             'and one more: ftp://127.0.0.1/.';
           $scope.snippetWithSingleURL = 'http://angularjs.org/';
         }]);
     </file>
     <file name="protractor.js" type="protractor">
       it('should linkify the snippet with urls', function() {
         expect(element(by.id('linky-filter')).element(by.binding('snippet | linky')).getText()).
             toBe('Pretty text with some links: http://angularjs.org/, us@somewhere.org, ' +
                  'another@somewhere.org, and one more: ftp://127.0.0.1/.');
         expect(element.all(by.css('#linky-filter a')).count()).toEqual(4);
       });

       it('should not linkify snippet without the linky filter', function() {
         expect(element(by.id('escaped-html')).element(by.binding('snippet')).getText()).
             toBe('Pretty text with some links: http://angularjs.org/, mailto:us@somewhere.org, ' +
                  'another@somewhere.org, and one more: ftp://127.0.0.1/.');
         expect(element.all(by.css('#escaped-html a')).count()).toEqual(0);
       });

       it('should update', function() {
         element(by.model('snippet')).clear();
         element(by.model('snippet')).sendKeys('new http://link.');
         expect(element(by.id('linky-filter')).element(by.binding('snippet | linky')).getText()).
             toBe('new http://link.');
         expect(element.all(by.css('#linky-filter a')).count()).toEqual(1);
         expect(element(by.id('escaped-html')).element(by.binding('snippet')).getText())
             .toBe('new http://link.');
       });

       it('should work with the target property', function() {
        expect(element(by.id('linky-target')).
            element(by.binding("snippetWithSingleURL | linky:'_blank'")).getText()).
            toBe('http://angularjs.org/');
        expect(element(by.css('#linky-target a')).getAttribute('target')).toEqual('_blank');
       });

       it('should optionally add custom attributes', function() {
        expect(element(by.id('linky-custom-attributes')).
            element(by.binding("snippetWithSingleURL | linky:'_self':{rel: 'nofollow'}")).getText()).
            toBe('http://angularjs.org/');
        expect(element(by.css('#linky-custom-attributes a')).getAttribute('rel')).toEqual('nofollow');
       });
     </file>
   </example>
 */
angular.module('ngSanitize').filter('linky', ['$sanitize', function($sanitize) {
  var LINKY_URL_REGEXP =
        /((s?ftp|https?):\/\/|(www\.)|(mailto:)?[A-Za-z0-9._%+-]+@)\S*[^\s.;,(){}<>"\u201d\u2019]/i,
      MAILTO_REGEXP = /^mailto:/i;

  var linkyMinErr = angular.$$minErr('linky');
  var isDefined = angular.isDefined;
  var isFunction = angular.isFunction;
  var isObject = angular.isObject;
  var isString = angular.isString;

  return function(text, target, attributes) {
    if (text == null || text === '') return text;
    if (!isString(text)) throw linkyMinErr('notstring', 'Expected string but received: {0}', text);

    var attributesFn =
      isFunction(attributes) ? attributes :
      isObject(attributes) ? function getAttributesObject() {return attributes;} :
      function getEmptyAttributesObject() {return {};};

    var match;
    var raw = text;
    var html = [];
    var url;
    var i;
    while ((match = raw.match(LINKY_URL_REGEXP))) {
      // We can not end in these as they are sometimes found at the end of the sentence
      url = match[0];
      // if we did not match ftp/http/www/mailto then assume mailto
      if (!match[2] && !match[4]) {
        url = (match[3] ? 'http://' : 'mailto:') + url;
      }
      i = match.index;
      addText(raw.substr(0, i));
      addLink(url, match[0].replace(MAILTO_REGEXP, ''));
      raw = raw.substring(i + match[0].length);
    }
    addText(raw);
    return $sanitize(html.join(''));

    function addText(text) {
      if (!text) {
        return;
      }
      html.push(sanitizeText(text));
    }

    function addLink(url, text) {
      var key, linkAttributes = attributesFn(url);
      html.push('<a ');

      for (key in linkAttributes) {
        html.push(key + '="' + linkAttributes[key] + '" ');
      }

      if (isDefined(target) && !('target' in linkAttributes)) {
        html.push('target="',
                  target,
                  '" ');
      }
      html.push('href="',
                url.replace(/"/g, '&quot;'),
                '">');
      addText(text);
      html.push('</a>');
    }
  };
}]);


})(window, window.angular);