All 2006-2008 Debian & Ubuntu crypto keys worthless
One day after the Debian Linux project announced a massive flaw where its implementation of OpenSSL key generators only used 15 bits of entropy (32,768 combinations), HD Moore (creator of Metasploit) has released a tool to exploit it. Nate McFeters has a good write up here on this matter. Because this bug is involves very obscure cryptographic concepts and the severity and scope of the flaw wasn’t easily understood, it didn’t really get a whole lot of media coverage. Now that the flaw can be exploited in Metasploit, the issue should get some attention. The flaw stems from the fact that the PRNG (Pseudo Random Number Generator) was crippled leaving it with only 32768 combinations to test. That means all RSA and DSA cryptographic keys generated by Debian and Ubuntu Linux distributions are effectively worthless. The impact of this exploit is massive and it can easily affect non-Linux systems like Windows or Mac if those computers have a Root Certificate generated from a Debian/Ubuntu computer. Any asymmetric crypto keys generated between September 2006 and 5/13/2008 on Debian or Ubuntu Linux distributions are affected. Every affected key needs to be revoked and regenerated. System administrator and security professionals everywhere should start auditing their computer for this very serious weakness as soon as possible. Update 4:32:PM c0uchw4rrior in comments below asked: “You mention Root Certs in the last paragraph. Does that include SSL web certs from Verisign/GoDaddy, etc?” This is a great question that I feel needs to be addressed in the body of the blog. It’s important to understand that Verisign and GoDaddy never creates your certificates; they merely sign the public key you generated. Your computer generated the public/private key-pair and this is what is at risk if you used a Debian/Ubuntu machine to generate the keys in the last 17 months. So if you paid $1000 to Verisign last month for them to sign a few certificates, you’re out of luck! You have to recreate the certificates and buy the signature from them again!