Re: [HACKERS] Query cancel and OOB data (fwd) - Mailing list pgsql-hackers

From Bruce Momjian
Subject Re: [HACKERS] Query cancel and OOB data (fwd)
Date
Msg-id 199805270439.AAA03509@candle.pha.pa.us
Whole thread Raw
In response to Re: [HACKERS] Query cancel and OOB data (fwd)  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-hackers
>
> Bruce Momjian <maillist@candle.pha.pa.us> writes:
> >> However, if they are already snooping, how much harder
> >> is it for them to insert their own query into the tcp stream?
>
> > Can someone answer this for me?
>
> Well, that depends entirely on what your threat model is --- for
> example, someone with read access on /dev/kmem on a relay machine
> might be able to watch packets going by, yet not be able to inject
> more.  On the other hand, someone with root privileges on another
> machine on your local LAN could likely do both.
>
> My guess is that most of the plausible cases that allow one also
> allow the other.  But it's only a guess.
>

Oh, yes, one more thing.  When generating the cancel key, We will have
to call random twice and return part of each so users will not see our
current random values.

When I remove the exec(), people will be able to call random() in the
backend to see the random value.  May need to reset the seed on
backend startup.


--
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