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On Tue, Jan 19, 2016 at 12:22 AM, <wabenbau@×××××.com> wrote: |
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> |
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> I'm an absolute windows noop. I only use it for graphics work. I even |
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> didn't know that such a kind of file sharing is possible with it. :-) |
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> |
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No worries - I think that is a great place to be. However, it is |
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useful to understand what ideas are out there, since some of them are |
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actually good ones. |
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The foundation of these kinds of features in windows is that their |
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user IDs are essentially GUIDs (a combination of an authentication |
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server and a unique ID I believe): |
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https://en.wikipedia.org/wiki/Security_Identifier |
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This is in contrast to a linux UID, which is just a small number. You |
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might be UID 0 on your box, and I'm UID on mine. The UID of the |
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administrator account of every windows box out there is unique. That |
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avoids all kinds of issues, like the whole nfs root-is-nobody design. |
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You can "chown" a windows file to a UID which isn't native to the |
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machine - the machine would authenticate anybody trying to read it |
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against the machine that assigned the UID. |
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It isn't perfect, but it seems like a better foundation for this sort of thing. |
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> |
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> That's right. I think that the effort and the outlay to implement all |
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> these features into Linux is relative high. It seems that no vendor |
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> is willing to assume such a financial risk. |
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> |
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> Maybe it is time for another crowd founding campaign? ;-) |
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> |
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Well, changing how user IDs would be a big task (as far as I'm aware). |
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However, the bit about Bitlocker isn't actually. You just need to use |
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trusted grub, some vanilla kernel config options, and probably some |
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logic in the initramfs and userspace. There is already a linux |
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solution for TPM at every layer of the boot chain, which allows a |
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userspace program in an initramfs to store an encryption key in the |
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TPM and retrieve it only if the boot chain isn't tampered with. You |
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just need to put together the pieces. |
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I could probably hack something together in a few days. The trick is |
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getting it to survive things like kernel updates and for it to be |
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robust. You need to ensure that anything that legitimately changes |
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your boot chain updates all the settings in the TPM so that on the |
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next boot the keys are still delivered. Otherwise your drive becomes |
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unreadable, and difficult to recover (well, unless you escrow the |
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encryption keys somewhere, which you certainly can do). |
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-- |
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Rich |
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