[TUHS] Maintenance mode on AIX

Joseph J. Mankoski ***PSI*** psi at valis.com
Thu Jan 19 06:04:19 AEST 2023


Hello --

        Regarding "appliance-ization" (locking down / dumbing down) of commercially-available computer systems, and returning to the history of Unix (in the context of our current era), I am reminded of Ken Thompson's (excellent and humorous) panel presentation at the ACM Turing 100 conference I attended in 2012, imagining Alan Turing being brought to our time and given a current-generation computer system, etc.

        The webcast links for the "Systems Architecture" session, etc., on the main conference site, https://turing100.acm.org/, seem to be broken, however the video at this link works for me:

        https://dl.acm.org/doi/10.1145/2322176.2322182

        (Ken's part starts at ~0:09:28.)

        Cheers,
                                ***PSI***
                                <<<psi at valis.com>>>

tuhs-request at tuhs.org writes:
[...]
>  ----------------------------------------------------------------------
>
>  Message: 1
>  Date: Wed, 18 Jan 2023 17:08:00 +0000
>  From: segaloco <segaloco at protonmail.com>
>  Subject: [TUHS] Re: Maintenance mode on AIX
>  To: Clem Cole <clemc at ccc.com>
>  Cc: tuhs at tuhs.org
>  Message-ID: <zpdIicuX7AbN-y6hYho0eLOnHgzRs4iHa1UD6bxUyiTZhqZkg3Ha8TKWV
>  	ASxWkDZitFw0JIopRVh7BRC2PzLFrF_Gjsb2yCi-uxJ3Yr3AtE=@protonmail.com>
>  Content-Type: multipart/alternative;
>  	boundary="b1_7WKJsCnT0P2jggZLBLwbL2iRavDFXPykjXdIMPRs"
>
>  Apple's unreasonable hardening has been the latest deterent to my ever wanting to use macOS as a personal driver. I've got a Mac as my daily driver for work, it can happily stay with work until I can decide how the filesystem is laid out and what folders I, as the root user, can and can't interact with from user land. I own my machine, not Apple.
>
>  - Matt G.
>  ------- Original Message -------
>  On Wednesday, January 18th, 2023 at 8:59 AM, Clem Cole <clemc at ccc.com> wrote:
>
>> On Wed, Jan 18, 2023 at 11:39 AM Larry McVoy <lm at mcvoy.com> wrote:
>>
>>> Someone once told me that if they had physical access to a Unix box, they
>>> would get root. That has been true forever and it's even more true today,
>>> pull the root disk, mount it on Linux, drop your ssh keys in there or add
>>> a no password root or setuid a shell, whatever, if you can put your hands
>>> on it, you can get in.
>>
>> A reasonable point, but I think it really depends on the UNIX implementation I suspect. Current mac OS is pretty well hardened from this, with their current enclaves and needing to boot home to Apple to get keys if things are not 100% right. Not saying you or I can not, but basically means the same cracking tricks you need to use for iPhones. It's not as easy as you describe.
>>
>> The ubiquitous Internet/WiFi changed the rules - as you can start to keep some set of keys somewhere else and then encrypt the local volumes. In fact, one of the things they do if mac OS boot detects that root has been modified (it has a crypto index stored away when it was made read-only), the boot rolls back to the last root snapshot -- since they are all read-only that works. In fact, it is a PITA to update/fix things like traditional scripts (for instance the scripts in the /etc/periodic area). Basically, they make it really unnatural to change the root files system, make a new snapshot and index (I have yet to see it documented although, with much pain, I previously created a procedure that is close -- i.e. it once worked on my pre-Ventura Mac - but currently -- fails, so I need to some more investigation when I can bring this back to the top of the importance/curiosity stack (I have a less than satisfying end around for now so I'm ignoring doing it properly).
>>
>> Clem
>> ᐧ-------------- next part --------------
[...]
>  ------------------------------
[...]


More information about the TUHS mailing list