loofah 0.4.7 Released

loofah version 0.4.7 has been released!

Loofah is a general library for manipulating and transforming HTML/XML documents and fragments. It’s built on top of Nokogiri and libxml2, so it’s fast and has a nice API.

Loofah excels at HTML sanitization (XSS prevention). It includes some nice HTML sanitizers, which are based on HTML5lib’s whitelist, so it most likely won’t make your codes less secure. (These statements have not been evaluated by Netexperts.)

== Changes

0.4.7 (2010-03-09)

Enhancements:

  • New methods Loofah::HTML::Document#to_text and Loofah::HTML::DocumentFragment#to_text do the right thing with whitespace. Note that these methods are significantly slower than #text. GH #12
  • Loofah::Elements::BLOCK_LEVEL contains a canonical list of HTML4 block-level4 elements.
  • Loofah::HTML::Document#text and Loofah::HTML::DocumentFragment#text will return unescaped HTML entities by passing :encode_special_chars => false.

== Features

  • Easily write custom scrubbers for HTML/XML leveraging the sweetness of Nokogiri (and HTML5lib’s whitelists).
  • Common HTML sanitizing tasks are built-in:
    • Strip unsafe tags, leaving behind only the inner text.
    • Prune unsafe tags and their subtrees, removing all traces that they ever existed.
    • Escape unsafe tags and their subtrees, leaving behind lots of < and > entities.
    • Whitewash the markup, removing all attributes and namespaced nodes.
  • Common HTML transformation tasks are built-in:
    • Add the nofollow attribute to all hyperlinks.
  • Format markup as plain text, with or without sensible whitespace handling around block elements.
  • Replace Rails’s +strip_tags+ and +sanitize+ helper methods.
  • Two ActiveRecord extensions:
    • Loofah::XssFoliate, an XssTerminate[http://github.com/look/xss_terminate/tree/master] drop-in replacement, is an opt-out sanitizer. By default all models and attributes are sanitized.
    • Loofah::ActiveRecordExtension is an opt-in sanitizer. You must explicitly declare attributes to be sanitized.

== Compare and Contrast

Loofah is one of two known Ruby XSS/sanitization solutions that guarantees well-formed and valid markup (the other is Sanitize, which also uses Nokogiri).

Loofah works fine on XML, XHTML and HTML documents.

Also, it’s pretty fast. Here is a benchmark comparing Loofah to other commonly-used libraries (ActionView, Sanitize, HTML5lib and HTMLfilter):

Lastly, Loofah is extensible. It’s super-easy to write your own custom scrubbers for whatever document manipulation you need. You don’t like the built-in scrubbers? Build your own, like a boss.