[Distutils] Replacing md5 hashes for packages on PyPI

[Richard Jones]

+1 pending detail

Sent from my mobile - please excuse any brevity.
On 13 Nov 2014 12:08, "Ian Cordasco" <graffatcolmingov at gmail.com> wrote:

> +1 from me as well
>
> On Wed, Nov 12, 2014 at 1:41 PM, Donald Stufft <donald at stufft.io> wrote:
> >
> >> On Nov 12, 2014, at 2:34 PM, Alex Gaynor <alex.gaynor at gmail.com> wrote:
> >>
> >> Hi everybody!
> >>
> >> Right now, PyPI provides MD5 hashes for packages, which is used by pip
> to
> >> check
> >> for corruption in transit. I'd like to propose we replace MD5 with
> SHA256 for
> >> PyPi, and move to deprecate MD5 support in pip and setuptools.
> >>
> >> Why should we do this? MD5 is broken. Collision resistance is totally
> 100%
> >> uselessly busted, and pre-image resistance is mathematically broken;
> practical
> >> attacks aren't known publicly, but it's reasonable to assume private
> attacks
> >> are strong because (sing it with me): "Attacks only get better".
> >>
> >> So MD5 doesn't provide the guarantees one might expect; SHA256 is not
> >> broken in
> >> these ways. But it's not just not providing value, it's actively causing
> >> problems: some machines, such as those with packages compiled to meet
> >> FIPS-140-2 do not have MD5 available at all, and so pip's verification
> raises
> >> an exception.
> >>
> >> While one might be inclined to find a way to silently support both
> machine
> >> configurations, I'd like to instead say we should abhor any additional
> >> configuration (whether user supplied or auto-detected) and instead
> simply
> >> upgrade the hashes offered by PyPI, and begin the deprecation process
> for
> >> MD5
> >> in pip.
> >>
> >> There are currently 60 packages on PyPI which are *not* hosted on PyPI,
> but
> >> do
> >> have MD5 hashes there. For these packages we could download the package,
> >> verify
> >> the MD5 hash, and then upgrade what PyPI stores to be SHA256.
> >
> >
> > +1 from me.
> >
> > Security wise pip supported sha256 before it supported TLS so for pip
> anything
> > that has the ability to securely fetch the sums from the /simple/ pages
> has
> > the ability to use sha256. For setuptools there was a small window where
> > setuptools implemented TLS verification (0.7) and implemented the
> support for
> > things other than MD5 (0.9). However I don’t think this small window
> represents
> > a large (or any?) number of users.
> >
> > IOW the impact should be non-existent other than having better digests.
> >
> > ---
> > Donald Stufft
> > PGP: 7C6B 7C5D 5E2B 6356 A926 F04F 6E3C BCE9 3372 DCFA
> >
> > _______________________________________________
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> _______________________________________________
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>
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