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Fox-IT Completes the Picture On the Factored RSA-512 Keys
An anonymous reader sends in this excerpt from the Fox-IT blog:
"During recent weeks we have observed several interesting publications which have a direct relation to an investigation we worked on recently. On one hand there was a Certificate Authority being revoked by Mozilla, Microsoft and Google (Chrome), on the other hand there was the disclosure of a malware attack by Mikko Hypponen (FSecure) using a government issued certificate signed by the same Certificate Authority. That case, however, is not self-contained, and a whole range of malicious software had been signed with valid certificates. The malicious software involved was used in targeted attacks focused on governments, political organizations and the defense industry. The big question is, of course, what happened, and how did the attackers obtain access to these certificates? We will explain here in detail how the attackers have used known techniques to bypass the Microsoft Windows code signing security model."
I guess it doesn't matter that I use one master password, since each account has been independently hacked.
-- Flame me and I will happily flame you back. Bring it!
The big question is, of course, what happened, and how did the attackers obtain access to these certificates?
The same thing that always happens, Pinky: Someone did a stupid thing. He or she was probably in management, since engineers are generally more careful (unless it's revision 2. Revision 2 is always evil)
#fuckbeta #iamslashdot #dicemustdie
For years now there have been some very vocal "security experts" who repeatedly trumpet how certificates and digital signatures somehow solve all security woes. Of course this isn't true, and we've tried to tell them this, but they refuse to listen.
Hopefully these recent incidents will shut them up once and for all. Certificates are nothing more than yet another tool in our security toolbox. To elevate them beyond this is a stupid thing to do, as these incidents rightfully show.
At the very least, I hope it makes these certificate freaks think twice before they recommend using certificates to solve some sort of a security problem.
RSA-512 is weak, can be factored in a few weeks (according to a comment, a couple days), and should never be used. All certificates should have CRL entries. Also, the Fox-IT International Blog writer needs English grammar courses.
"None can love freedom heartily, but good men; the rest love not freedom, but license." --John Milton
The Slashdot story last week about the Malaysian Government certificate that was "stolen" referred to a certificate from a Department of Agriculture website, but I think the more newsworthy revelation in this article is that payments.bnm.gov.my was using one of the 512 bit RSA keys that has been compromised. BNM (Bank Negara Malaysia) is the equivalent of US Treasury, or Bank of England.
I see DigiNotar and DigiCert Authorities in Firefox's Certificate Manager.
Should I be concerned about these?
Is there a revocation list I need to know about?
Using Firefox 8.0 on Ubuntu, for what it's worth...
Big sites which can afford the $$$ can get a CA signature which is meaningfully secure and trustworthy. Which is great for them but not so good for the vast bulk of sites which might like to use encryption but don't because obtaining and maintaining a cert is a huge pain in the ass. So they continue with plaintext. And if we look at those big sites, surely a Toys R Us would find more worth in a cert which was signed by Lego, Microsoft, Visa, Mastercard and so on than by some obscure CA? Companies whom the visitor is likely to recognize and would have some kind of reciprocal business relationship.
So instead of a rigid CA signature it seems to me a lot better to implement a web of trust. Google could host a key signing party and get Microsoft, Amazon, PayPal, Mozilla to attend. Each in turn might hold some satellite key signing parties to sign more keys and keep going out until the top 500 or so sites are covered by each. Every signatory signs with an email address and puts their public key up on a well defined location on that domain, e.g. the public key for security@keys.google.com might be at keys.google.com/security. A browser is preloaded with public keys for the major sites and is capable of caching any it doesn't have. There would also be some kind of revocation model. Trust could be graded anywhere from ultimate to weak. When a browser visits a site it validates the site's signatories and their trust to the ones in its list and poses an appropriate form of information or error to the user depending on what it finds.
The point is that web of trust would allow sites to make their own trust in a manner that suits them and their visitors. And it doesn't stop CAs from selling their own signatures as part of the web of trust either much like some already do for PGP, or through the more rigid CA model. But what it does do is stop CAs being a mandatory part of the equation. People will be able to generating certs in an adhoc fashion. That to me is a far better model, and one which would stand a good chance of making security the default rather than an after thought that some sites practice and not others.
there was the disclosure of a malware attack by Mikko Hypponen (FSecure) using a government issued certificate signed by the same Certificate Authority.
No, there was the disclosure by Mikko Hypponen of a malware attack using a government issued certificate. Mikko did not perform the attack.