[openssl-dev] Work on a new RNG for OpenSSL

[Tomas Mraz]

On Thu, 2017-08-17 at 22:11 +0200, Kurt Roeckx wrote:
> On Thu, Aug 17, 2017 at 02:34:49PM +0200, Tomas Mraz wrote:
> > On Thu, 2017-08-17 at 12:22 +0000, Salz, Rich via openssl-dev
> > wrote:
> > > I understand the concern.  The issue I am wrestling with is
> > > strict
> > > compatibility with the existing code.  Does anyone really *want*
> > > the
> > > RNG’s to not reseed on fork?  It’s hard to imagine, but maybe
> > > somewhere someone is.  And then it’s not about just reseeding,
> > > but
> > > what about when (if) we add other things, like whether or not the
> > > secure arena gets zero’d in a child?
> > > 
> > > So let me phrase it this way:  does anyone object to changing the
> > > default so NO_ATFORK must be used to avoid the reseeding and
> > > other
> > > things we might add later?
> > 
> > I can hardly see anyone would be broken if the default is to reseed
> > RNG on fork. However that might not be true for other atfork
> > functionalities so perhaps there is a need to make each of these
> > future
> > atfork functions configurable and either on or off by default
> > individually and not as a whole.
> 
> There might be cases where after fork you're not able to get to
> /dev/urandom anymore.

I do not think so. Which particular cases do you have on mind? Yes,
after fork+exec you could for example switch SELinux domain and won't
be able to access something but immediately after fork it should not be
so. Also perhaps the reseeding after fork can be made less strict in
regards to failures reading /dev/urandom or so.

-- 
Tomáš Mráz
Red Hat

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