Let's clean up our terminology a bit. New terminology:
FSS = Forward Secure Sealing
FSPRG = Forward Secure Pseudo-Random Generator
FSS is the combination of FSPRG and a HMAC.
Sealing = process of adding authentication tags to the journal.
Verification = process of checking authentication tags to the journal.
Sealing Key = The key used for adding authentication tags to the journal.
Verification Key = The key used for checking authentication tags of the journal.
Key pair = The pair of Sealing Key and Verification Key
Internally, the Sealing Key is the combination of the FSPRG State plus
change interval/start time.
Internally, the Verification Key is the combination of the FSPRG Seed
plus change interval/start time.
instead of having one simple per-file cache implement an more
comprehensive one that works for multiple files and can actually
maintain multiple maps per file and per object type.
In some cases, like wrong configuration, restarting after error
does not help, so administrator can specify statuses by RestartPreventExitStatus
which will not cause restart of a service.
Sometimes you have non-standart exit status, so this can be specified
by SuccessfulExitStatus.
This adds forward-secure authentication of journal files. This patch
includes key generation as well as tagging of journal files,
Verification of journal files will be added in a later patch.
- don't use pivot_root() anymore, just reuse root hierarchy
- first create all mounts, then mark them read-only so that we get the
right behaviour when people want writable mounts inside of
read-only mounts
- don't pass invalid combinations of MS_ constants to the kernel
The kernel does not allow switching roots if things are mounted
MS_SHARED. As a work-around, remount things MS_PRIVATE before switching
roots.
This should be fixed in the kernel for good.
https://bugzilla.redhat.com/show_bug.cgi?id=847418
Lennart Poettering
Kay Sievers
Zbigniew Jędrzejewski-Szmek
Martin Pitt
Lukas Nykryn