OpenSSL To Undergo Major Audit

The first major public audit of OpenSSL will soon be underway, backed by the Linux Foundation's Core Infrastructure Initiative -- a $1.2 million open-source research fund established last spring in the wake of Heartbleed. The audit will be one of the first well-funded efforts to harden open-source infrastructure, historically financed only by researchers' free time, sense of civic duty, and community spirit. 

"The amount of time and work this is going to take, just trying to do it on nights and weekends is not going to yield good results," says Tom Ritter, principal security consultant of NCC Group, which is part of Cryptography Services, the team conducting the audit.

In April 2014, 12 leading technology firms -- Amazon Web Services, Cisco, Dell, Facebook, Fujitsu, Google, IBM, Intel, Microsoft, NetApp, RackSpace, and VMware -- agreed to contribute $100,000 apiece per year, for the next three years, to the Initiative. 

When deciding where those resources would go, "OpenSSL was the frontrunner," says Ritter. "It hadn't had as much attention paid to it as it should have."

Never was that clearer than last year when the critical Heartbleed vulnerability in OpenSSL's implementation of the Transport Layer Security (TLS) protocol's "heartbeat" extension was discovered. Although Ritter says the team does not know what they'll find when they begin the audit, clearly Heartbleed is part of their thought process; as Ritter explained in a blog post today:

The audit’s primary focus is on the TLS stacks, covering protocol flow, state transitions, and memory management. We’ll also be looking at the BIOs, most of the high-profile cryptographical algorithms, and setting up fuzzers for the ASN.1 and x509 parsers.

"If you do an audit," says Ritter, "you get the most value out of it if you've done some preparation." The OpenSSL community has done such preparation, he says, by hiring more staff and completing a reformatting of its codebase earlier this month.

Ritter says the audit will take several months to complete, and expects to publish results over the summer.