Re: [PATCH 0/4] Reproducible binaries

[Patrick Ohly <patrick.ohly@intel.com>]

On Tue, 2017-04-25 at 19:22 -0400, Trevor Woerner wrote:
> On Tue, Apr 25, 2017 at 2:14 PM, Juro Bystricky
> <juro.bystricky@intel.com> wrote:
> > The variable defaults to "0" (do not
> > build reproducible binaries) in order to minimize any potential
> > regressions. (Once the reproducible binaries code is mature enough,
> > it can be set to "1".)
> 
> My guess is that people would prefer security over reproducibility.

When all machines targeted by an attack run the same build, they also
share the same seeds, regardless whether that build was reproducible or
not. In that case it doesn't matter, the attack method and complexity
would be the same with or without reproducibility.

It gets a bit harder when targeting multiple different OS builds, but
relying on randomness in the build as a defense against attacks isn't
particularly secure.

If people prefer security, they shouldn't use prelinking and ensure that
the machines comes up with good, per-machine entropy for the random
number generation that needs to happen on the machine.

How much does reproducibility then still matter? I suspect not that
much.

> Maybe we need more consensus for the default value going forward?

Yes, it's worth considering.

-- 
Best Regards, Patrick Ohly

The content of this message is my personal opinion only and although
I am an employee of Intel, the statements I make here in no way
represent Intel's position on the issue, nor am I authorized to speak
on behalf of Intel on this matter.