Mozilla Aims to Improve Firefox Browser SSL Security

The open-source browser vendor offers a $10,000 bug bounty for flaws found in a new SSL certificate validation library.

Open-source Firefox browser vendor Mozilla is looking to improve security with a new certificate validation library set to debut in Firefox 31 later this year. Certificates are widely used on the Internet today for Secure Socket Layers (SSL) encryption as a way to secure data in motion.

Since its inception, Firefox has used technology known as Network Security Services (NSS) to help validate the integrity of security certificates used for an SSL session. Mozilla is now trying out a new security library called mozilla::pkix to enhance and improve certificate validation checking.

"It's a new validation library that replaces some of the functionality in NSS, but we will still need most of NSS in concert with mozilla::pkix,"Sid Stamm, senior engineering manager for security and privacy at Mozilla, explained to eWEEK.

There are multiple mechanisms in use in Web browsers today to validate SSL certificates. Among them are certificate revocation lists (CRLs) and the Online Certificate Status Protocol (OCSP). Stamm emphasized that what Mozilla is doing with mozilla::pkix is a different thing.

"OCSP and CRL are ways for certificate authorities to tell interested parties if they've revoked a certificate," Stamm said. "mozilla::pkix does the math to determine if a certificate is valid, and may use OCSP or CRL to help decide."

Mozilla has been continuously working to improve Firefox security over the years. The Firefox 27 browser, which was released in February, included support for the Transport Layer Security (TLS) 1.2 specification. TLS 1.2 was first defined in August 2008, offering security enhancements over prior versions of TLS and SSL.

Stamm noted that the version of the TLS protocol used between client and server is independent of the certificate validation done by the client.

"Mozilla::pkix sits beside the TLS connections and verifies certificates that are used by TLS," Stamm explained.

He added that every network security protocol Firefox currently supports will continue to be supported, and that mozilla::pkix enables Mozilla to innovate more quickly and effectively with future security features and protections.

"We hope mozilla::pkix, being a more streamlined piece of software created directly for this purpose, will be more secure than the code we are replacing," Stamm said.


While Mozilla expects that most server admins will not need to change anything for mozilla::pkix to work, the organization does want server administrators to help test the new library with their Websites, Stamm said. The mozilla::pkix library will begin to enforce requirements that in the past have been only required by policy. Mozilla has listed the various specific requirements on a wiki page.

Going a step further, in an effort to make sure that the new library is as secure as possible, Mozilla is also offering a $10,000 bug bounty to security researchers who are able to discover vulnerabilities in the code.

"This code is brand new, and we want to focus the security community on eradicating any bugs it has as quickly as possible," Stamm said. "In addition, mozilla::pkix is intended to secure the communications of Firefox users, so we want extra testing for correctness on this new library before it goes out to all of our users."

Sean Michael Kerner is a senior editor at eWEEK and Follow him on Twitter @TechJournalist.

Sean Michael Kerner

Sean Michael Kerner

Sean Michael Kerner is an Internet consultant, strategist, and contributor to several leading IT business web sites.