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On Mon, Sep 09, 2013 at 04:30:31PM +0100, thegeezer wrote: |
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> >> i read in slashdot that there is a question mark over SELinux because it came |
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> >> from the NSA [4] but this is nonsense, as it is a means of securing processes |
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> >> not network connections. i find it difficult to believe that a backdoor in a |
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> >> locked cupboard in your house can somehow give access through the front door. |
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> > This point you get wrong. SELinux implement the LSM API (in fact the LSM API |
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> > was tailored to SELinux needs). It has hooks in nearly everything |
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> > (file/directory access, process access and also sockets). One of the biggest |
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> > concerns at the time of creation of the LSM API was rootkits hooking that |
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> > functions. It's definitively a thread. I'm not saying that SELinux contains |
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> > a backdoor (I for myself would have hidden it in the LSM part, not in SELinux |
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> > because that would enable me to use it even if other LSMs are used). If you |
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> > google for "underhanded C contest" you'll see that it's possible to hide |
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> > malicious behaviour in plain sight. And if the kernel is compromised all other |
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> > defenses mean nothing. (As I said, I don't want to spread fearbut that is |
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> > something to consider imho). |
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> Interesting, I didn't realise LSM provisioned hooks for SELinux - |
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> thought it it was more modular (and less 'shoehorned') than that. |
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> I need to go read about that some more now |
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You can start here: |
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http://www.freetechbooks.com/efiles/selinuxnotebook/The_SELinux_Notebook_The_Foundations_3rd_Edition.pdf |
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for a general overview (page 64ff has a list of the hooks). |
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Other than that http://www.kroah.com/linux/talks/ols_2002_lsm_paper/lsm.pdf and |
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http://www.nsa.gov/research/_files/publications/implementing_selinux.pdf may be |
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of interest (though both are quite old). |
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WKR |
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Hinnerk |