John, Just wondering what the Tails Linux distro (https://tails.boum.org/) does in this regard of initial seeding for /dev/urandom from their Live CD distro. Do you know? Since it is a LOT more common for people to run (only?) from the Live distro for Tails, having an unpredictable PRNG stream would arguably more relevant there.
I don't know what I did with my Tails CD (and plus it's probably several years old), otherwise I'd fire it up and look. But perhaps if they did it right, maybe we can just point to them for a better approach. Alternately, if you know where the Ubuntu Live CD "builder" script(s) are, maybe the better approach is to just make a Git pull request and associate it with this bug report. If they had a fix in-hand or one they could copy from, then I think this would be more likely to change the importance from "undecided" to at least Low, or maybe Medium/ (I doubt it will ever be seen more important than that, assuming they use a H, M, L scale.) It might even get assigned to someone in that case too. -kevin On Fri, Dec 23, 2016 at 2:03 PM, John Denker <l...@av8n.com> wrote: > I see the importance is still "undecided". Here is something that may > help: > > Message from Rich Salz, 12/22/2016 10:06 AM: >> Feel free to quote me: >> This is very important. > [...] >> Rich Salz >> Senior Architect, Akamai Technologies >> Member, OpenSSL Dev Team > > High-quality randomly-distributed numbers are needed for every aspect of > computer > security, including long-term keys, session keys, nonces, initialization > vectors, > ASLR, et cetera. > > Newly-installed systems need randomness just as much as other systems. > > -- > You received this bug notification because you are subscribed to the bug > report. > https://bugs.launchpad.net/bugs/1651947 > > Title: > installer ought to install a proper random-seed > > Status in livecd-rootfs package in Ubuntu: > New > Status in ubiquity package in Ubuntu: > New > > Bug description: > Observed behavior: The Ubuntu "Live CD" installer creates > a file on the installee (i.e. target) filesystem called > /var/lib/systemd/random-seed > but alas it has zero length. > > Desired behavior: The installer should copy 512 bytes from > the installer's /dev/urandom into the installee's > /var/lib/systemd/random-seed > > Discussion: The newly installed system relies on that file > to initialize its random number generator. It might have > other ways of initializing, or it might not. An improperly > initialized RNG creates grave security problems. > > There is no imaginable downside to doing this. > > Remark: The Debian installer handles this better. It gives the > installee a nice > /var/lib/urandom/random-seed > file with 512 bytes of random content. It does not bother with > /var/lib/systemd/random-seed > at all. > > The Ubuntu installer, in contrast, creates a directory > /var/lib/urandom > with no contents, i.e. no files at all. Perhaps this is vestigial. > Suggestion: The Ubuntu installer should: > a) not create that directory at all, or > b) create /var/lib/urandom/random-seed as a symlink to > ../systemd/random-seed, or > c) put the actual data in /var/lib/urandom/random-seed -- > which is the traditional and compatible place for it -- and > teach the systemd scripts to find it there. > > Disclaimer: As a separate matter, it is important to ensure > that the installer system itself has a properly initialized RNG. > There are ways of doing so, but that is a topic for another day. > For present purposes, the point is only that the installer should > not make things worse. It should use whatever randomness it has > to initialize the installee system. > > -------------------------------- > > Observed on a Live CD system: > :; lsb_release -rd > Description: Ubuntu 16.04.1 LTS > Release: 16.04 > > The package is: > :; apt-cache policy ubiquity > ubiquity: > Installed: 2.21.63.2 > Candidate: 2.21.63.2 > Version table: > *** 2.21.63.2 500 > 500 http://archive.ubuntu.com/ubuntu xenial-updates/main amd64 > Packages > 100 /var/lib/dpkg/status > 2.21.63 500 > 500 http://archive.ubuntu.com/ubuntu xenial/main amd64 Packages > > To manage notifications about this bug go to: > https://bugs.launchpad.net/ubuntu/+source/livecd-rootfs/+bug/1651947/+subscriptions -- Blog: http://off-the-wall-security.blogspot.com/ | Twitter: @KevinWWall NSA: All your crypto bit are belong to us. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1651947 Title: installer ought to install a proper random-seed To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/livecd-rootfs/+bug/1651947/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
