[HEADSUP] geli(4) weak master key generation on -CURRENT

[Ulrich Spörlein]

On Mon, 2012-08-20 at 22:24:56 +0100, Simon L. B. Nielsen wrote:
> Hello,
> 
> If you are not using geli(4) on -CURRENT (AKA FreeBSD 10) you can safely
> ignore this mail. If you are, please read on!
> 
> -CURRENT users of geli(4) should be advised that, a geli(4) device may
> have weak master key, if the provider is created on -CURRENT system
> built against source code between r238116 (Jul 4 17:54:17 2012 UTC)
> and r239184 (non-inclusive, Aug 10 18:43:29 2012 UTC).
> 
> One can verify if its provider was created with weak keys by running:
> 
> 	# geli dump <provider> | grep version
> 
> If the version is 7 and the system did not include this fix (r239184)
> when provider was initialized, then the data has to be backed up,
> underlying provider overwritten with random data, system upgraded and
> provider recreated.
> 
> Thanks to Fabian Keil for reporting the issue, Pawel Jakub Dawidek for
> fixing it, and Xin Li for drafting this text.
> 
> PS. This only affects FreeBSD 10 / -CURRENT, and as -CURRENT isn't
> supported by the FreeBSD Security Team, we are not releasing an
> advisory, just this heads up.

I haven't read commit mails in a very long time, but is there code in
place that will issue a warning upon geli attach if version 7 is
detected? While -CURRENT is not supported, there might be a lot of disks
initialized with version 7 and they'll eventually be upgraded to
10.0-RELEASE (the OS, not necessarily the geli volumes).

Thanks
Uli