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Faster string escaping routines for your ruby apps

README.md

escape_utils

Being as though we're all html escaping everything these days, why not make it faster?

For character encoding in 1.9, the output string's encoding is copied from the input string.

It has monkey-patches for Rack::Utils, CGI, URI, ERB::Util and Haml and ActionView so you can drop this in and have your app start escaping fast as balls in no time

It supports HTML, URL, URI and Javascript escaping/unescaping.

Installing

Compatible with Ruby 1.9.3+

gem install escape_utils

Warning: UTF-8 only

escape_utils assumes all input is encoded as valid UTF-8. If you are dealing with other encodings do your best to transcode the string into a UTF-8 byte stream before handing it to escape_utils.

utf8_string = non_utf8_string.encode('UTF-8')

Usage

HTML

Escaping

html = `curl -s http://maps.google.com`
escaped_html = EscapeUtils.escape_html(html)

By default escape_utils will escape / characters with /, but you can disable that by setting EscapeUtils.html_secure = false or per-call by passing false as the second parameter to escape_html like EscapeUtils.escape_html(html, false)

For more information check out: http://www.owasp.org/index.php/XSS_(Cross_Site_Scripting)_Prevention_Cheat_Sheet#RULE_.231_-_HTML_Escape_Before_Inserting_Untrusted_Data_into_HTML_Element_Content

Unescaping

html = `curl -s http://maps.google.com`
escaped_html = EscapeUtils.escape_html(html)
html = EscapeUtils.unescape_html(escaped_html)

Monkey Patches

require 'escape_utils/html/rack' # to patch Rack::Utils
require 'escape_utils/html/erb' # to patch ERB::Util
require 'escape_utils/html/cgi' # to patch CGI
require 'escape_utils/html/haml' # to patch Haml::Helpers

URL

Use (un)escape_uri to get RFC-compliant escaping (like PHP rawurlencode).

Use (un)escape_url to get CGI escaping (where space is +).

Escaping

url = "https://www.yourmom.com/cgi-bin/session.cgi?sess_args=mcEA~!!#*YH*>@!U"
escaped_url = EscapeUtils.escape_url(url)

Unescaping

url = "https://www.yourmom.com/cgi-bin/session.cgi?sess_args=mcEA~!!#*YH*>@!U"
escaped_url = EscapeUtils.escape_url(url)
EscapeUtils.unescape_url(escaped_url) == url # => true

Monkey Patches

require 'escape_utils/url/cgi' # to patch CGI
require 'escape_utils/url/erb' # to patch ERB::Util
require 'escape_utils/url/rack' # to patch Rack::Utils
require 'escape_utils/url/uri' # to patch URI

Javascript

Escaping

javascript = `curl -s http://code.jquery.com/jquery-1.4.2.js`
escaped_javascript = EscapeUtils.escape_javascript(javascript)

Unescaping

javascript = `curl -s http://code.jquery.com/jquery-1.4.2.js`
escaped_javascript = EscapeUtils.escape_javascript(javascript)
EscapeUtils.unescape_javascript(escaped_javascript) == javascript # => true

Monkey Patches

require 'escape_utils/javascript/action_view' # to patch ActionView::Helpers::JavaScriptHelper

Benchmarks

In my testing, escaping html is around 10-30x faster than the pure ruby implementations in wide use today. While unescaping html is around 40-100x faster than CGI.unescapeHTML which is also pure ruby. Escaping Javascript is around 16-30x faster.

This output is from my laptop using the benchmark scripts in the benchmarks folder.

HTML

Escaping

Rack::Utils.escape_html
 9.650000   0.090000   9.740000 (  9.750756)
Haml::Helpers.html_escape
 9.310000   0.110000   9.420000 (  9.417317)
ERB::Util.html_escape
 5.330000   0.390000   5.720000 (  5.748394)
CGI.escapeHTML
 5.370000   0.380000   5.750000 (  5.791344)
FasterHTMLEscape.html_escape
 0.520000   0.010000   0.530000 (  0.539485)
fast_xs_extra#fast_xs_html
 0.310000   0.030000   0.340000 (  0.336734)
EscapeUtils.escape_html
 0.200000   0.050000   0.250000 (  0.258839)

Unescaping

CGI.unescapeHTML
 16.520000   0.080000  16.600000 ( 16.853888)
EscapeUtils.unescape_html
 0.120000   0.040000   0.160000  (  0.162696)

Javascript

Escaping

ActionView::Helpers::JavaScriptHelper#escape_javascript
 3.810000   0.100000   3.910000 (  3.925557)
EscapeUtils.escape_javascript
 0.200000   0.040000   0.240000 (  0.236692)

Unescaping

I didn't look that hard, but I'm not aware of another ruby library that does Javascript unescaping to benchmark against. Anyone know of any?

URL

Escaping

ERB::Util.url_encode
 0.520000   0.010000   0.530000 (  0.529277)
Rack::Utils.escape
 0.460000   0.010000   0.470000 (  0.466962)
CGI.escape
 0.440000   0.000000   0.440000 (  0.443017)
URLEscape#escape
 0.040000   0.000000   0.040000 (  0.045661)
fast_xs_extra#fast_xs_url
 0.010000   0.000000   0.010000 (  0.015429)
EscapeUtils.escape_url
 0.010000   0.000000   0.010000 (  0.010843)

Unescaping

Rack::Utils.unescape
 0.250000   0.010000   0.260000 (  0.257558)
CGI.unescape
 0.250000   0.000000   0.250000 (  0.257837)
URLEscape#unescape
 0.040000   0.000000   0.040000 (  0.031548)
fast_xs_extra#fast_uxs_cgi
 0.010000   0.000000   0.010000 (  0.006062)
EscapeUtils.unescape_url
 0.000000   0.000000   0.000000 (  0.005679)
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