OWASP Java HTML Sanitizer Project

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• 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://github.com/OWASP/java-html-sanitizer/blob/master/docs/getting_started.md. 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 and is dual licensed under the Apache 2 License and the New BSD License.

What is this? The OWASP HTML Sanitizer Projects provides Java based HTML sanitization of untrusted HTML! Code Repo OWASP HTML Sanitizer at GitHub Email List Questions? Please sign up for our Project Support List Project Leaders Author/Project Leader Mike Samuel @ Project Manager Jim Manico @ Related Projects XSS (Cross Site Scripting) Prevention Cheat Sheet OWASP JSON Sanitizer OWASP Java Encoder Project OWASP Dependency Check OWASP AntiSamy Sourceclear Headlines Google KeyCzar Apache SHIRO Ohloh https://www.ohloh.net/p/owasp-java-html-sanitizer

Quick Download v239 at Maven Central JavaDoc v239 News and Events [2 July 2014] v239 Released [3 Mar 2014] v226 Released [5 Feb 2014] New Wiki [4 Sept 2013] v209 Released Change Log For recent release notes, please visit the changelog on Google Code. Classifications Apache 2 License

You can use prepackaged policies here: https://github.com/OWASP/java-html-sanitizer/blob/master/src/main/java/org/owasp/html/Sanitizers.java.

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

or the tests show how to configure your own policy here: https://github.com/OWASP/java-html-sanitizer/blob/master/src/test/java/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://github.com/OWASP/java-html-sanitizer/blob/master/docs/getting_started.md