OWASP Java HTML Sanitizer Project

• Main
• Creating a HTML Policy
• Questions

OWASP HTML Sanitizer Project The OWASP HTML Sanitizer is a fast and easy to configure HTML Sanitizer written in Java which lets you include HTML authored by third-parties in your web application while protecting against XSS. The existing dependencies are on guava and JSR 305. The other jars are only needed by the test suite. The JSR 305 dependency is a compile-only dependency, only needed for annotations. This code was written with security best practices in mind, has an extensive test suite, and has undergone adversarial security review. A great place to get started using the OWASP Java HTML Sanitizer is here: https://code.google.com/p/owasp-java-html-sanitizer/wiki/GettingStarted. Benefits Provides 4X the speed of AntiSamy sanitization in DOM mode and 2X the speed of AntiSamy in SAX mode. Very easy to use. It allows for simple programmatic POSITIVE policy configuration (see below). No XML config. Actively maintained by Mike Samuel from Google's AppSec team! Passing 95+% of AntiSamy's unit tests plus many more. This is code from the Caja project that was donated by Google. It is rather high performance and low memory utilization. Java 1.5+ Licensing The OWASP HTML Sanitizer is free to use under the Apache 2 License.

What is this? The OWASP HTML Sanitizer Projects provides: Java based HTML sanitization of untrusted HTML! Code Repo OWASP HTML Sanitizer at Google Code Email List Project Email List Project Leader Project Leader: Mike Samuel Contributors: Jim Manico Related Projects XSS (Cross Site Scripting) Prevention Cheat Sheet OWASP JSON Sanitizer OWASP Java Encoder Project OWASP AntiSamy

Quick Download https://owasp-java-html-sanitizer.googlecode.com/files/owasp-java-html-sanitizer-r226.zip News and Events [3 Mar 2014] 226 Released [5 Feb 2014] New Wiki [4 Sept 2013] 209 Released Releases v226 bug fixes v209 bug fixes 44-209 Classifications Apache 2 License

You can use prepackaged policies here: http://owasp-java-html-sanitizer.googlecode.com/svn/trunk/distrib/javadoc/org/owasp/html/Sanitizers.html.

PolicyFactory policy = Sanitizers.FORMATTING.and(Sanitizers.LINKS);
String safeHTML = policy.sanitize(untrustedHTML);

or the tests show how to configure your own policy here: http://code.google.com/p/owasp-java-html-sanitizer/source/browse/trunk/src/tests/org/owasp/html/HtmlPolicyBuilderTest.java

PolicyFactory policy = new HtmlPolicyBuilder()
   .allowElements("a")
   .allowUrlProtocols("https")
   .allowAttributes("href").onElements("a")
   .requireRelNofollowOnLinks()
   .build();
String safeHTML = policy.sanitize(untrustedHTML);

or you can write custom policies to do things like changing h1s to divs with a certain class:

PolicyFactory policy = new HtmlPolicyBuilder()
   .allowElements("p")
   .allowElements(
       new ElementPolicy() {
         public String apply(String elementName, List<String> attrs) {
           attrs.add("class");
           attrs.add("header-" + elementName);
           return "div";
         }
       }, "h1", "h2", "h3", "h4", "h5", "h6"))
   .build();
String safeHTML = policy.sanitize(untrustedHTML);

• How was this project tested?
  • This code was written with security best practices in mind, has an extensive test suite, and has undergone adversarial security review.
• How is this project deployed?
  • This project is best deployed through Maven https://code.google.com/p/owasp-java-html-sanitizer/wiki/Maven