5 ms·
From the link ... How did this happen? "When we [Microsoft] initially identified that an older cryptography algorithm could be exploited and then be used to si
by SlipperySlope 14y ago
From the link ...
How did this happen?
"When we [Microsoft] initially identified that an older cryptography algorithm could be exploited and then be used to sign code as if it originated from Microsoft, we immediately began investigating Microsoft’s signing infrastructure to understand how this might be possible. What we found is that certificates issued by our Terminal Services licensing certification authority, which are intended to only be used for license server verification, could also be used to sign code as Microsoft. Specifically, when an enterprise customer requests a Terminal Services activation license, the certificate issued by Microsoft in response to the request allows code signing without accessing Microsoft’s internal PKI infrastructure."
Interesting. The Microsoft Terminal Services CA has the corporate identity, but not the corporate trust chain. Is this a deliberate back-door provided to the US government, or simply an ordinary vulnerability?
We need some sort of certification, an independent audit, of X509 certificate authorities and their trust chains. Agreed?
- eli 14y agoI guess there's no way to prove that isn't deliberate, but that smells like the rather more common failure to implement crypto systems properly.
- jness 14y agoAllowing code signing with a certificate that we generate for and hand out to enterprise customers was certainly not something we intended to do at Microsoft. It was sloppy and a mistake on our part that we rushed to address as soon as we discovered the issue. Honestly, I think many of us are terribly embarrassed by this failure and a little surprised that no one (us included) had discovered this issue years ago. :(
- rdl 14y agoI agree that is by far the most likely case, but if you wanted to give the USG a backdoor to sign code, this is also exactly how you'd do it -- as a deniable oversight, which, when found, could be explained as a simple oversight and rapidly corrected.
- eli 14y agoFrankly, if I were going to create a deliberate backdoor I'd make it harder to find than this. I wonder when it was first discovered.
- rdl 14y agoYeah, so would I. It also got put in one ago, which is before putting back doors into commodity OSes was such a useful thing for national security (probably compromising crypto systems and specific RF hardware used in air defense, etc was the primary goal back then). I probably wouldnt rush to fix a convenient exploit once discovered, though, if existing USG policies could protect against it (removing most CAs, using DOD CAs) for government operations.
- cpeterso 14y agoHumans are always the weakest link. I worked on Microsoft's crypto QA team many years ago. VeriSign issued some test certificates for our internal testing. A co-worker called VeriSign customer service, asking them to revoke one of the test certificates so we could test CRLs (Certificate Revocation Lists). Without any additional authentication or verification, the customer service person revoked Microsoft Corporation's root certificate! This was misunderstanding was quickly remedied, but it was a perfect demonstration that CA trust chains is a house of cards.