In response to Sami's comments on ANTP: The MUST is that if you use RSA, the key length is >= 2048 bits. The protocol supports any public key encryption scheme, and ECDH is listed as an option as well. Similarly, AES-CBC+HMAC-SHA is one possible authenticated encryption scheme. The others you mention would work just fine as well.
Changing the crypto algorithms wouldn't make the protocol much simpler, IMO. If you have suggestions for simplifications (while preserving ANTP's security) I'd like to hear them. Simplicity was one of our design goals, and when compared to the other options referenced in the paper, I think we succeeded. -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to ntp in Ubuntu. https://bugs.launchpad.net/bugs/1039420 Title: NTP security vulnerability because not using authentication by default Status in ntp package in Ubuntu: Confirmed Bug description: Ubuntu implements so much security one way or another. So much defenses against network level man in the middle or malicious proxies or wifi hotspots. Cryptographic verification generally works well but there is one big drawback: it requires correct date/time. NTP in Ubuntu does not use any authentication by default, although it is supported by NTP. I conclude, that almost no one is using authenticated NTP, because there are no instructions in a forum or blog how to enable NTP authentication. Therefore almost everyone uses standard configuration and is at risk. An adversary can tamper with the unauthenticated NTP replies and put the users time several years back, especially, but not limited, if the bios battery or hardware clock is defect. That issue becomes more relevant with new devices like RP, which do not even have a hardware clock. Putting the clock several years back allows an adversary to use already revoked, broken, expired certificates; replay old, broken, outdated, known vulnerable updates etc. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/ntp/+bug/1039420/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
