[rsbac] new features
cesare at ucci.it
Tue Nov 2 14:43:38 CET 2004
I have a proposal for a couple of new small features, they are not so
clear in my mind, so please see if they could be useful or not. Actually
I believe that it is possible to obtain similar results by using normal
tools, but the way I think could be easier.
I would like to add a couple of kernel parameters like:
this will be like rsbac_softmode, that is boot in softmode, but once
softmode has been turned off, it cannot be turned on again for the
uptime of the machine
this is probably more tricky, any RSBAC configuration should be
disallowed in secure mode, tools and /proc could be read_only but not
allow to change any RSBAC configuration, moreover this should apply
only when softmode is off, when softmode is on secoff should work as
Notice that the functionality of the two parameters overlaps, if you use
the second you do not need the first. Indeed if you boot with
linux rsbac_softmode rsbac_secoff_disabled
as soon as in the boot scripts you switch off softmode, you cannot
switch it on again because all RSBAC tools do not work anymore. But if I
need to do maintenance of the machine, I just boot without the
rsbac_secoff_disabled parameter. This allows me to protect
lilo.conf/grub.conf read_only with RSBAC and be sure that I can do
maintenance only from the console.
The rsbac_softmode_noback is a soft version of the second, in this case
I can use the rsbac admin tools, except for "switch softmode on", this
can allow to mantain a remote server in such a way that softmode can be
allowed only with a reboot (first make lilo.conf/grub.conf writable with
the RSBAC admin tools, then change lilo.conf/grub.conf, then reboot). I
guess that a similar effect can be obtained with a careful
configuration, but I fear that in most conditions secoff would be able
to reverse the configuration and allow itself to switch softmode on
without reboot, since the kernel has softmode configured in.
Notice that in both cases I am considering machines which for some
reasons must boot in softmode.
Please let me know if I can obtained similar behaviour with what there
is already, or if there are kernel parameters which can give the same
PS. Where can I find the complete current list of kernel parameters
without need of reading the source ?
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