Feeds

How poor crypto housekeeping left OpenID open to abuse

Internet bouncer snooze leads to 'small earthquake'

Choosing a cloud hosting partner with confidence

Slipshod cryptographic housekeeping left some OpenID services far less secure than they ought to be.

OpenID is a shared identity service that enables users to eliminate the need for punters to create separate IDs and logins for websites that support the service. A growing number of around 9,000 websites support the decentralised service, which offers a a URL-based system for single sign-on.

Security researchers discovered the websites run by three OpenID providers - including Sun Microsystems - used SSL certificates with weak crypto keys. Instead of being generated from billions of possibilities, the keys came from a a set of just 32,768 options, due to a flaw in the random number generation routines used by Debian. The bug, which has been dormant on systems for 18 months, was discovered and corrected back in May.

Keys generated by cryptographically flawed systems still needed to be replaced even after the software was upgraded. But recent research by Ben Laurie of Google reveals that 1.5 per cent of certificates he looked at contained weak keys. Three OpenID providers (openid.sun.com, xopenid.net and openid.net.nz) were among the guilty parties.

To exploit the vulnerability, malicious hackers would need to trick surfers into visiting a site impersonating a pukka OpenID provider. But faking digital certificate alone wouldn't do the trick without first misdirecting surfers to these bogus sites. Dan Kaminsky's recent discovery of a DNS cache poisoning flaw made it far more plausible to construct an attack that sent surfers the wrong away around the net's address lookup system, potentially to a bogus Open site posing as the real deal.

The security flaw meant that even cautious users who check SSL certificates were at risk of handing over their OpenID credentials as part of a phishing attack. Such an attack would take a lot of effort to pull off and would only yield OpenID login credentials, which aren't especially useful for hackers and are difficult to monetise.

Going after online banking credentials via a site that makes no attempt to offer up fake SSL certificates is a far more reliable moneyspinner, a factor that leads noted security researcher Richard Clayton to describe the attack as the "modern equivalent of a small earthquake in Chile".

Sun has responded to the issue by generating a new secure key, which reduces the scope for mischief but still leaves potential problems from the old key.

More thoughts on the cryptographically interesting - though not especially life-threatening - flaw can be found in Clayton's posting on Cambridge University's Light the Blue Touchpaper blog here. A security advisory by Laurie and Clayton explaining the issue in greater depth can be found here. ®

Beginner's guide to SSL certificates

More from The Register

next story
Russian hackers exploit 'Sandworm' bug 'to spy on NATO, EU PCs'
Fix imminent from Microsoft for Vista, Server 2008, other stuff
FYI: OS X Yosemite's Spotlight tells Apple EVERYTHING you're looking for
It's on by default – didn't you read the small print?
Microsoft pulls another dodgy patch
Redmond makes a hash of hashing add-on
'LulzSec leader Aush0k' found to be naughty boy not worthy of jail
15 months home detention leaves egg on feds' faces as they grab for more power
Kill off SSL 3.0 NOW: HTTPS savaged by vicious POODLE
Pull it out ASAP, it is SWISS CHEESE
Facebook slurps 'paste sites' for STOLEN passwords, sprinkles on hash and salt
Zuck's ad empire DOESN'T see details in plain text. Phew!
Admins! Never mind POODLE, there're NEW OpenSSL bugs to splat
Four new patches for open-source crypto libraries
prev story

Whitepapers

Forging a new future with identity relationship management
Learn about ForgeRock's next generation IRM platform and how it is designed to empower CEOS's and enterprises to engage with consumers.
Cloud and hybrid-cloud data protection for VMware
Learn how quick and easy it is to configure backups and perform restores for VMware environments.
Three 1TB solid state scorchers up for grabs
Big SSDs can be expensive but think big and think free because you could be the lucky winner of one of three 1TB Samsung SSD 840 EVO drives that we’re giving away worth over £300 apiece.
Reg Reader Research: SaaS based Email and Office Productivity Tools
Read this Reg reader report which provides advice and guidance for SMBs towards the use of SaaS based email and Office productivity tools.
Security for virtualized datacentres
Legacy security solutions are inefficient due to the architectural differences between physical and virtual environments.