From 911899f569e8e906ab1ee1c5be00dece1bec2431 Mon Sep 17 00:00:00 2001
From: Juanito Fatas <juanito.fatas@shopify.com>
Date: Thu, 21 Mar 2019 10:05:14 +0900
Subject: [PATCH] Migrate to SafeListSanitizer

SafeList is easier to understand
---
 README.md                   | 20 +++++------
 lib/rails-html-sanitizer.rb | 12 +++++--
 lib/rails/html/sanitizer.rb | 39 +++++++++++---------
 test/sanitizer_test.rb      | 72 ++++++++++++++++++-------------------
 4 files changed, 77 insertions(+), 66 deletions(-)

diff --git a/README.md b/README.md
index ed01f05..b3e9fb0 100644
--- a/README.md
+++ b/README.md
@@ -41,22 +41,22 @@ link_sanitizer.sanitize('<a href="example.com">Only the link text will be kept.<
 # => Only the link text will be kept.
 ```
 
-#### WhiteListSanitizer
+#### SafeListSanitizer
 
 ```ruby
-white_list_sanitizer = Rails::Html::WhiteListSanitizer.new
+safe_list_sanitizer = Rails::Html::SafeListSanitizer.new
 
-# sanitize via an extensive white list of allowed elements
-white_list_sanitizer.sanitize(@article.body)
+# sanitize via an extensive safe list of allowed elements
+safe_list_sanitizer.sanitize(@article.body)
 
-# white list only the supplied tags and attributes
-white_list_sanitizer.sanitize(@article.body, tags: %w(table tr td), attributes: %w(id class style))
+# safe list only the supplied tags and attributes
+safe_list_sanitizer.sanitize(@article.body, tags: %w(table tr td), attributes: %w(id class style))
 
-# white list via a custom scrubber
-white_list_sanitizer.sanitize(@article.body, scrubber: ArticleScrubber.new)
+# safe list via a custom scrubber
+safe_list_sanitizer.sanitize(@article.body, scrubber: ArticleScrubber.new)
 
-# white list sanitizer can also sanitize css
-white_list_sanitizer.sanitize_css('background-color: #000;')
+# safe list sanitizer can also sanitize css
+safe_list_sanitizer.sanitize_css('background-color: #000;')
 ```
 
 ### Scrubbers
diff --git a/lib/rails-html-sanitizer.rb b/lib/rails-html-sanitizer.rb
index 494a56f..f8d1736 100644
--- a/lib/rails-html-sanitizer.rb
+++ b/lib/rails-html-sanitizer.rb
@@ -15,8 +15,14 @@ def link_sanitizer
           Html::LinkSanitizer
         end
 
+        def safe_list_sanitizer
+          Html::SafeListSanitizer
+        end
+
         def white_list_sanitizer
-          Html::WhiteListSanitizer
+          ActiveSupport::Deprecation.warn "warning: white_list_sanitizer is" \
+          "deprecated, please use safe_list_sanitizer instead."
+          safe_list_sanitizer
         end
       end
     end
@@ -34,7 +40,7 @@ module ClassMethods
         #   end
         #
         def sanitized_allowed_tags=(tags)
-          sanitizer_vendor.white_list_sanitizer.allowed_tags = tags
+          sanitizer_vendor.safe_list_sanitizer.allowed_tags = tags
         end
 
         # Replaces the allowed HTML attributes for the +sanitize+ helper.
@@ -44,7 +50,7 @@ def sanitized_allowed_tags=(tags)
         #   end
         #
         def sanitized_allowed_attributes=(attributes)
-          sanitizer_vendor.white_list_sanitizer.allowed_attributes = attributes
+          sanitizer_vendor.safe_list_sanitizer.allowed_attributes = attributes
         end
 
         [:protocol_separator,
diff --git a/lib/rails/html/sanitizer.rb b/lib/rails/html/sanitizer.rb
index 7fc6994..f9bef9f 100644
--- a/lib/rails/html/sanitizer.rb
+++ b/lib/rails/html/sanitizer.rb
@@ -57,8 +57,8 @@ def sanitize(html, options = {})
       end
     end
 
-    # === Rails::Html::WhiteListSanitizer
-    # Sanitizes html and css from an extensive white list (see link further down).
+    # === Rails::Html::SafeListSanitizer
+    # Sanitizes html and css from an extensive safe list (see link further down).
     #
     # === Whitespace
     # We can't make any guarantees about whitespace being kept or stripped.
@@ -72,34 +72,34 @@ def sanitize(html, options = {})
     # so automatically.
     #
     # === Options
-    # Sanitizes both html and css via the white lists found here:
+    # Sanitizes both html and css via the safe lists found here:
     # https://github.com/flavorjones/loofah/blob/master/lib/loofah/html5/whitelist.rb
     #
-    # WhiteListSanitizer also accepts options to configure
-    # the white list used when sanitizing html.
+    # SafeListSanitizer also accepts options to configure
+    # the safe list used when sanitizing html.
     # There's a class level option:
-    # Rails::Html::WhiteListSanitizer.allowed_tags = %w(table tr td)
-    # Rails::Html::WhiteListSanitizer.allowed_attributes = %w(id class style)
+    # Rails::Html::SafeListSanitizer.allowed_tags = %w(table tr td)
+    # Rails::Html::SafeListSanitizer.allowed_attributes = %w(id class style)
     #
     # Tags and attributes can also be passed to +sanitize+.
     # Passed options take precedence over the class level options.
     #
     # === Examples
-    # white_list_sanitizer = Rails::Html::WhiteListSanitizer.new
+    # safe_list_sanitizer = Rails::Html::SafeListSanitizer.new
     #
     # Sanitize css doesn't take options
-    # white_list_sanitizer.sanitize_css('background-color: #000;')
+    # safe_list_sanitizer.sanitize_css('background-color: #000;')
     #
-    # Default: sanitize via a extensive white list of allowed elements
-    # white_list_sanitizer.sanitize(@article.body)
+    # Default: sanitize via a extensive safe list of allowed elements
+    # safe_list_sanitizer.sanitize(@article.body)
     #
-    # White list via the supplied tags and attributes
-    # white_list_sanitizer.sanitize(@article.body, tags: %w(table tr td),
+    # Safe list via the supplied tags and attributes
+    # safe_list_sanitizer.sanitize(@article.body, tags: %w(table tr td),
     # attributes: %w(id class style))
     #
-    # White list via a custom scrubber
-    # white_list_sanitizer.sanitize(@article.body, scrubber: ArticleScrubber.new)
-    class WhiteListSanitizer < Sanitizer
+    # Safe list via a custom scrubber
+    # safe_list_sanitizer.sanitize(@article.body, scrubber: ArticleScrubber.new)
+    class SafeListSanitizer < Sanitizer
       class << self
         attr_accessor :allowed_tags
         attr_accessor :allowed_attributes
@@ -146,7 +146,12 @@ def allowed_tags(options)
 
       def allowed_attributes(options)
         options[:attributes] || self.class.allowed_attributes
-      end
+      end      
+    end
+
+    WhiteListSanitizer = SafeListSanitizer
+    if Object.respond_to?(:deprecate_constant)
+      deprecate_constant :WhiteListSanitizer
     end
   end
 end
diff --git a/test/sanitizer_test.rb b/test/sanitizer_test.rb
index 7bcab6f..4369ab0 100644
--- a/test/sanitizer_test.rb
+++ b/test/sanitizer_test.rb
@@ -12,12 +12,12 @@ def test_sanitizer_sanitize_raises_not_implemented_error
   end
 
   def test_sanitize_nested_script
-    sanitizer = Rails::Html::WhiteListSanitizer.new
+    sanitizer = Rails::Html::SafeListSanitizer.new
     assert_equal '&lt;script&gt;alert("XSS");&lt;/script&gt;', sanitizer.sanitize('<script><script></script>alert("XSS");<script><</script>/</script><script>script></script>', tags: %w(em))
   end
 
   def test_sanitize_nested_script_in_style
-    sanitizer = Rails::Html::WhiteListSanitizer.new
+    sanitizer = Rails::Html::SafeListSanitizer.new
     assert_equal '&lt;script&gt;alert("XSS");&lt;/script&gt;', sanitizer.sanitize('<style><script></style>alert("XSS");<style><</style>/</style><style>script></style>', tags: %w(em))
   end
 
@@ -255,38 +255,38 @@ def test_custom_attributes_overrides_allowed_attributes
 
   def test_should_allow_custom_tags
     text = "<u>foo</u>"
-    assert_equal text, white_list_sanitize(text, tags: %w(u))
+    assert_equal text, safe_list_sanitize(text, tags: %w(u))
   end
 
   def test_should_allow_only_custom_tags
     text = "<u>foo</u> with <i>bar</i>"
-    assert_equal "<u>foo</u> with bar", white_list_sanitize(text, tags: %w(u))
+    assert_equal "<u>foo</u> with bar", safe_list_sanitize(text, tags: %w(u))
   end
 
   def test_should_allow_custom_tags_with_attributes
     text = %(<blockquote cite="http://example.com/">foo</blockquote>)
-    assert_equal text, white_list_sanitize(text)
+    assert_equal text, safe_list_sanitize(text)
   end
 
   def test_should_allow_custom_tags_with_custom_attributes
     text = %(<blockquote foo="bar">Lorem ipsum</blockquote>)
-    assert_equal text, white_list_sanitize(text, attributes: ['foo'])
+    assert_equal text, safe_list_sanitize(text, attributes: ['foo'])
   end
 
   def test_scrub_style_if_style_attribute_option_is_passed
     input = '<p style="color: #000; background-image: url(http://www.ragingplatypus.com/i/cam-full.jpg);"></p>'
-    assert_equal '<p style="color: #000;"></p>', white_list_sanitize(input, attributes: %w(style))
+    assert_equal '<p style="color: #000;"></p>', safe_list_sanitize(input, attributes: %w(style))
   end
 
   def test_should_raise_argument_error_if_tags_is_not_enumerable
     assert_raises ArgumentError do
-      white_list_sanitize('<a>some html</a>', tags: 'foo')
+      safe_list_sanitize('<a>some html</a>', tags: 'foo')
     end
   end
 
   def test_should_raise_argument_error_if_attributes_is_not_enumerable
     assert_raises ArgumentError do
-      white_list_sanitize('<a>some html</a>', attributes: 'foo')
+      safe_list_sanitize('<a>some html</a>', attributes: 'foo')
     end
   end
 
@@ -295,7 +295,7 @@ def test_should_not_accept_non_loofah_inheriting_scrubber
     def scrubber.scrub(node); node.name = 'h1'; end
 
     assert_raises Loofah::ScrubberNotFound do
-      white_list_sanitize('<a>some html</a>', scrubber: scrubber)
+      safe_list_sanitize('<a>some html</a>', scrubber: scrubber)
     end
   end
 
@@ -304,19 +304,19 @@ def test_should_accept_loofah_inheriting_scrubber
     def scrubber.scrub(node); node.name = 'h1'; end
 
     html = "<script>hello!</script>"
-    assert_equal "<h1>hello!</h1>", white_list_sanitize(html, scrubber: scrubber)
+    assert_equal "<h1>hello!</h1>", safe_list_sanitize(html, scrubber: scrubber)
   end
 
   def test_should_accept_loofah_scrubber_that_wraps_a_block
     scrubber = Loofah::Scrubber.new { |node| node.name = 'h1' }
     html = "<script>hello!</script>"
-    assert_equal "<h1>hello!</h1>", white_list_sanitize(html, scrubber: scrubber)
+    assert_equal "<h1>hello!</h1>", safe_list_sanitize(html, scrubber: scrubber)
   end
 
   def test_custom_scrubber_takes_precedence_over_other_options
     scrubber = Loofah::Scrubber.new { |node| node.name = 'h1' }
     html = "<script>hello!</script>"
-    assert_equal "<h1>hello!</h1>", white_list_sanitize(html, scrubber: scrubber, tags: ['foo'])
+    assert_equal "<h1>hello!</h1>", safe_list_sanitize(html, scrubber: scrubber, tags: ['foo'])
   end
 
   [%w(img src), %w(a href)].each do |(tag, attr)|
@@ -468,7 +468,7 @@ def test_x03a_legitimate
   end
 
   def test_sanitize_ascii_8bit_string
-    white_list_sanitize('<a>hello</a>'.encode('ASCII-8BIT')).tap do |sanitized|
+    safe_list_sanitize('<a>hello</a>'.encode('ASCII-8BIT')).tap do |sanitized|
       assert_equal '<a>hello</a>', sanitized
       assert_equal Encoding::UTF_8, sanitized.encoding
     end
@@ -481,37 +481,37 @@ def test_sanitize_data_attributes
 
   def test_allow_data_attribute_if_requested
     text = %(<a data-foo="foo">foo</a>)
-    assert_equal %(<a data-foo="foo">foo</a>), white_list_sanitize(text, attributes: ['data-foo'])
+    assert_equal %(<a data-foo="foo">foo</a>), safe_list_sanitize(text, attributes: ['data-foo'])
   end
 
-  def test_uri_escaping_of_href_attr_in_a_tag_in_white_list_sanitizer
+  def test_uri_escaping_of_href_attr_in_a_tag_in_safe_list_sanitizer
     html = %{<a href='examp<!--" unsafeattr=foo()>-->le.com'>test</a>}
 
-    text = white_list_sanitize(html)
+    text = safe_list_sanitize(html)
 
     assert_equal %{<a href="examp<!--%22%20unsafeattr=foo()>-->le.com">test</a>}, text
   end
 
-  def test_uri_escaping_of_src_attr_in_a_tag_in_white_list_sanitizer
+  def test_uri_escaping_of_src_attr_in_a_tag_in_safe_list_sanitizer
     html = %{<a src='examp<!--" unsafeattr=foo()>-->le.com'>test</a>}
 
-    text = white_list_sanitize(html)
+    text = safe_list_sanitize(html)
 
     assert_equal %{<a src="examp<!--%22%20unsafeattr=foo()>-->le.com">test</a>}, text
   end
 
-  def test_uri_escaping_of_name_attr_in_a_tag_in_white_list_sanitizer
+  def test_uri_escaping_of_name_attr_in_a_tag_in_safe_list_sanitizer
     html = %{<a name='examp<!--" unsafeattr=foo()>-->le.com'>test</a>}
 
-    text = white_list_sanitize(html)
+    text = safe_list_sanitize(html)
 
     assert_equal %{<a name="examp<!--%22%20unsafeattr=foo()>-->le.com">test</a>}, text
   end
 
-  def test_uri_escaping_of_name_action_in_a_tag_in_white_list_sanitizer
+  def test_uri_escaping_of_name_action_in_a_tag_in_safe_list_sanitizer
     html = %{<a action='examp<!--" unsafeattr=foo()>-->le.com'>test</a>}
 
-    text = white_list_sanitize(html, attributes: ['action'])
+    text = safe_list_sanitize(html, attributes: ['action'])
 
     assert_equal %{<a action="examp<!--%22%20unsafeattr=foo()>-->le.com">test</a>}, text
   end
@@ -530,35 +530,35 @@ def link_sanitize(input, options = {})
     Rails::Html::LinkSanitizer.new.sanitize(input, options)
   end
 
-  def white_list_sanitize(input, options = {})
-    Rails::Html::WhiteListSanitizer.new.sanitize(input, options)
+  def safe_list_sanitize(input, options = {})
+    Rails::Html::SafeListSanitizer.new.sanitize(input, options)
   end
 
   def assert_sanitized(input, expected = nil)
     if input
-      assert_dom_equal expected || input, white_list_sanitize(input)
+      assert_dom_equal expected || input, safe_list_sanitize(input)
     else
-      assert_nil white_list_sanitize(input)
+      assert_nil safe_list_sanitize(input)
     end
   end
 
   def sanitize_css(input)
-    Rails::Html::WhiteListSanitizer.new.sanitize_css(input)
+    Rails::Html::SafeListSanitizer.new.sanitize_css(input)
   end
 
   def scope_allowed_tags(tags)
-    old_tags = Rails::Html::WhiteListSanitizer.allowed_tags
-    Rails::Html::WhiteListSanitizer.allowed_tags = tags
-    yield Rails::Html::WhiteListSanitizer.new
+    old_tags = Rails::Html::SafeListSanitizer.allowed_tags
+    Rails::Html::SafeListSanitizer.allowed_tags = tags
+    yield Rails::Html::SafeListSanitizer.new
   ensure
-    Rails::Html::WhiteListSanitizer.allowed_tags = old_tags
+    Rails::Html::SafeListSanitizer.allowed_tags = old_tags
   end
 
   def scope_allowed_attributes(attributes)
-    old_attributes = Rails::Html::WhiteListSanitizer.allowed_attributes
-    Rails::Html::WhiteListSanitizer.allowed_attributes = attributes
-    yield Rails::Html::WhiteListSanitizer.new
+    old_attributes = Rails::Html::SafeListSanitizer.allowed_attributes
+    Rails::Html::SafeListSanitizer.allowed_attributes = attributes
+    yield Rails::Html::SafeListSanitizer.new
   ensure
-    Rails::Html::WhiteListSanitizer.allowed_attributes = old_attributes
+    Rails::Html::SafeListSanitizer.allowed_attributes = old_attributes
   end
 end