create HTML sanitizer to allow inclusion of untrusted HTML in safe manner.

Sanitization works in two phases:
 1) We parse the HTML into sax-like events (start, end, chars).
    HTML parsing is very complex, and so it may very well be that what
    most browser consider valid HTML may not pares properly here,
    but we do best effort. We treat this parser as untrusted.
 2) We have safe sanitizeWriter which treats its input (start, end, chars)
    as untrusted content and escapes everything. It only allows elements
    in the whitelist and only allows attributes which are whitelisted.
    Any attribute value must not start with 'javascript:'. This check
    is performed after escaping for entity (&xAB; etc..) and ignoring
    any whitespace.

 - Correct linky filter to use safeHtmlWriter
 - Correct html filter to use safeHtmlWriter

Close #33; Close #34

1 files changed, 154 insertions, 0 deletions

diff --git a/test/sanitizerSpec.js b/test/sanitizerSpec.js
new file mode 100644
index 00000000..4e1ff355
--- /dev/null
+++ b/test/sanitizerSpec.js
@@ -0,0 +1,154 @@
+describe('HTML', function(){
+
+  function expectHTML(html) {
+    return expect(new HTML(html).get());
+  }
+
+  it('should echo html', function(){
+    expectHTML('hello<b class="1\'23" align=\'""\'>world</b>.').
+       toEqual('hello<b class="1\'23" align="&quot;&quot;">world</b>.');
+  });
+
+  it('should remove script', function(){
+    expectHTML('a<SCRIPT>evil< / scrIpt >c.').toEqual('ac.');
+  });
+
+  it('should remove nested script', function(){
+    expectHTML('a< SCRIPT >A< SCRIPT >evil< / scrIpt >B< / scrIpt >c.').toEqual('ac.');
+  });
+
+  it('should remove attrs', function(){
+    expectHTML('a<div style="abc">b</div>c').toEqual('a<div>b</div>c');
+  });
+
+  it('should remove style', function(){
+    expectHTML('a<STyle>evil</stYle>c.').toEqual('ac.');
+  });
+
+  it('should remove script and style', function(){
+    expectHTML('a<STyle>evil<script></script></stYle>c.').toEqual('ac.');
+  });
+
+  it('should remove double nested script', function(){
+    expectHTML('a<SCRIPT>ev<script>evil</sCript>il</scrIpt>c.').toEqual('ac.');
+  });
+
+  it('should remove unknown tag names', function(){
+    expectHTML('a<xxx><B>b</B></xxx>c').toEqual('a<b>b</b>c');
+  });
+
+  it('should remove unsafe value', function(){
+    expectHTML('<a href="javascript:alert()">').toEqual('<a></a>');
+  });
+
+  it('should handle self closed elements', function(){
+    expectHTML('a<hr/>c').toEqual('a<hr/>c');
+  });
+
+  it('should handle namespace', function(){
+    expectHTML('a<my:hr/><my:div>b</my:div>c').toEqual('abc');
+  });
+
+  it('should handle improper html', function(){
+    expectHTML('< div id="</div>" alt=abc href=\'"\' >text< /div>').
+      toEqual('<div id="&lt;/div&gt;" alt="abc" href="&quot;">text</div>');
+  });
+
+  it('should handle improper html2', function(){
+    expectHTML('< div id="</div>" / >').
+      toEqual('<div id="&lt;/div&gt;"/>');
+  });
+
+  describe('htmlSanitizerWriter', function(){
+    var writer, html;
+    beforeEach(function(){
+      html = '';
+      writer = htmlSanitizeWriter({push:function(text){html+=text;}});
+    });
+
+    it('should write basic HTML', function(){
+      writer.chars('before');
+      writer.start('div', {id:'123'}, false);
+      writer.chars('in');
+      writer.end('div');
+      writer.chars('after');
+
+      expect(html).toEqual('before<div id="123">in</div>after');
+    });
+
+    it('should escape text nodes', function(){
+      writer.chars('a<div>&</div>c');
+      expect(html).toEqual('a&lt;div&gt;&amp;&lt;/div&gt;c');
+    });
+
+    it('should not double escape entities', function(){
+      writer.chars('&nbsp;&gt;&lt;');
+      expect(html).toEqual('&nbsp;&gt;&lt;');
+    });
+
+    it('should escape IE script', function(){
+      writer.chars('&{}');
+      expect(html).toEqual('&amp;{}');
+    });
+
+    it('should escape attributes', function(){
+      writer.start('div', {id:'\"\'<>'});
+      expect(html).toEqual('<div id="&quot;\'&lt;&gt;">');
+    });
+
+    it('should ignore missformed elements', function(){
+      writer.start('d>i&v', {});
+      expect(html).toEqual('');
+    });
+
+    it('should ignore unknown attributes', function(){
+      writer.start('div', {unknown:""});
+      expect(html).toEqual('<div>');
+    });
+
+    describe('javascript URL attribute', function(){
+      beforeEach(function(){
+        this.addMatchers({
+          toBeValidUrl: function(){
+            return !isJavaScriptUrl(this.actual);
+          }
+        });
+      });
+
+      it('should ignore javascript:', function(){
+        expect('JavaScript:abc').not.toBeValidUrl();
+        expect(' \n Java\n Script:abc').not.toBeValidUrl();
+        expect('JavaScript/my.js').toBeValidUrl();
+      });
+
+      it('should ignore dec encoded javascript:', function(){
+        expect('&#106;&#97;&#118;&#97;&#115;&#99;&#114;&#105;&#112;&#116;&#58;').not.toBeValidUrl();
+        expect('&#106&#97;&#118;&#97;&#115;&#99;&#114;&#105;&#112;&#116;&#58;').not.toBeValidUrl();
+        expect('&#106 &#97;&#118;&#97;&#115;&#99;&#114;&#105;&#112;&#116;&#58;').not.toBeValidUrl();
+      });
+
+      it('should ignore decimal with leading 0 encodede javascript:', function(){
+        expect('&#0000106&#0000097&#0000118&#0000097&#0000115&#0000099&#0000114&#0000105&#0000112&#0000116&#0000058').not.toBeValidUrl();
+        expect('&#0000106 &#0000097&#0000118&#0000097&#0000115&#0000099&#0000114&#0000105&#0000112&#0000116&#0000058').not.toBeValidUrl();
+        expect('&#0000106; &#0000097&#0000118&#0000097&#0000115&#0000099&#0000114&#0000105&#0000112&#0000116&#0000058').not.toBeValidUrl();
+      });
+
+      it('should ignore hex encoded javascript:', function(){
+        expect('&#x6A&#x61&#x76&#x61&#x73&#x63&#x72&#x69&#x70&#x74&#x3A;').not.toBeValidUrl();
+        expect('&#x6A;&#x61&#x76&#x61&#x73&#x63&#x72&#x69&#x70&#x74&#x3A;').not.toBeValidUrl();
+        expect('&#x6A &#x61&#x76&#x61&#x73&#x63&#x72&#x69&#x70&#x74&#x3A;').not.toBeValidUrl();
+      });
+
+      it('should ignore hex encoded whitespace javascript:', function(){
+        expect('jav&#x09;ascript:alert("A");').not.toBeValidUrl();
+        expect('jav&#x0A;ascript:alert("B");').not.toBeValidUrl();
+        expect('jav&#x0A ascript:alert("C");').not.toBeValidUrl();
+        expect('jav\u0000ascript:alert("D");').not.toBeValidUrl();
+        expect('java\u0000\u0000script:alert("D");').not.toBeValidUrl();
+        expect(' &#14; java\u0000\u0000script:alert("D");').not.toBeValidUrl();
+      });
+    });
+
+  });
+
+});