[gentoo-dev] integrity of stage files

[gentoo-dev] integrity of stage files

["Paweł Hajdan, Jr."]

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I checked
<http://www.gentoo.org/doc/en/handbook/handbook-x86.xml?part=1&chap=5>
and the Handbook only mentions validating MD5 checksums.

There are two possible issues:

1. Why are we using _only_ MD5 and SHA1 as the checksums? Shouldn't we
be using something stronger?

2. I noticed the checksums are signed (.asc files). With what key are
they signed? How is that key handled, and how to ensure people use the
right key when verifying the signature?

Paweł


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Re: [gentoo-dev] integrity of stage files

[Robin H. Johnson]

On Sat, Oct 08, 2011 at 02:45:02PM -0700, "Paweł Hajdan, Jr." wrote:
> I checked
> <http://www.gentoo.org/doc/en/handbook/handbook-x86.xml?part=1&chap=5>
> and the Handbook only mentions validating MD5 checksums.
> 
> There are two possible issues:
> 
> 1. Why are we using _only_ MD5 and SHA1 as the checksums? Shouldn't we
> be using something stronger?
Fixed in Catalyst now.
http://git.overlays.gentoo.org/gitweb/?p=proj/catalyst.git;a=commit;h=42b4f6608682cf03954918ecce7923330a1656fe
So when the stagebuilders update their Catalyst, they will be generated
with newer hashes.

> 2. I noticed the checksums are signed (.asc files). With what key are
> they signed? How is that key handled, and how to ensure people use the
> right key when verifying the signature?
Documented here:
http://www.gentoo.org/proj/en/releng/

Relevant to this discussion:
The weekly builds are signed with:
key 2D182910 RSA 4096-bit, generated 2009/08/25
Gentoo Linux Release Engineering (Automated Weekly Release Key) <releng@gentoo.org>

It's located in the pipeline that collects stages and isos for publication.

The non-weekly releases (eg 11.2) have a separate key
key 17072058, DSA 1024-bit, generated 2004/07/20
Gentoo Linux Release Engineering (Gentoo Linux Release Signing Key) <releng@gentoo.org>

-- 
Robin Hugh Johnson
Gentoo Linux: Developer, Trustee & Infrastructure Lead
E-Mail     : robbat2@gentoo.org
GnuPG FP   : 11AC BA4F 4778 E3F6 E4ED  F38E B27B 944E 3488 4E85

Re: [gentoo-dev] integrity of stage files

["Paweł Hajdan, Jr."]

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On 10/8/11 3:43 PM, Robin H. Johnson wrote:
>> 1. Why are we using _only_ MD5 and SHA1 as the checksums? Shouldn't we
>> be using something stronger?
> Fixed in Catalyst now.
> http://git.overlays.gentoo.org/gitweb/?p=proj/catalyst.git;a=commit;h=42b4f6608682cf03954918ecce7923330a1656fe
> So when the stagebuilders update their Catalyst, they will be generated
> with newer hashes.

Thank you for a quick reaction, but maybe in one aspect it was too
quick:
<http://www.gentoo.org/doc/en/handbook/handbook-x86.xml?part=1&chap=5>
tells people to use md5sum, and the patch above _removes_ md5 sum, which
means the Handbook instructions now won't work.

Suggested course of action:

1. Please re-add md5 sum.
2. File a bug to modify the handbook to verify sha sum instead.
3. Then remove the checksum.

>> 2. I noticed the checksums are signed (.asc files). With what key are
>> they signed? How is that key handled, and how to ensure people use the
>> right key when verifying the signature?
> Documented here:
> http://www.gentoo.org/proj/en/releng/

Ah, I just forgot about that page. Okay, so can we also update the
Handbook to include GPG signature checking?


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Re: [gentoo-dev] integrity of stage files

[Robin H. Johnson]

On Sat, Oct 08, 2011 at 04:39:40PM -0700, "Paweł Hajdan, Jr." wrote:
> On 10/8/11 3:43 PM, Robin H. Johnson wrote:
> >> 1. Why are we using _only_ MD5 and SHA1 as the checksums? Shouldn't we
> >> be using something stronger?
> > Fixed in Catalyst now.
> > http://git.overlays.gentoo.org/gitweb/?p=proj/catalyst.git;a=commit;h=42b4f6608682cf03954918ecce7923330a1656fe
> > So when the stagebuilders update their Catalyst, they will be generated
> > with newer hashes.
> 
> Thank you for a quick reaction, but maybe in one aspect it was too
> quick:
> <http://www.gentoo.org/doc/en/handbook/handbook-x86.xml?part=1&chap=5>
> tells people to use md5sum, and the patch above _removes_ md5 sum, which
> means the Handbook instructions now won't work.
> 
> Suggested course of action:
> 
> 1. Please re-add md5 sum.
Done.
> 2. File a bug to modify the handbook to verify sha sum instead.
https://bugs.gentoo.org/show_bug.cgi?id=386475

> 3. Then remove the checksum.
> 
> >> 2. I noticed the checksums are signed (.asc files). With what key are
> >> they signed? How is that key handled, and how to ensure people use the
> >> right key when verifying the signature?
> > Documented here:
> > http://www.gentoo.org/proj/en/releng/
> Ah, I just forgot about that page. Okay, so can we also update the
> Handbook to include GPG signature checking?
It DOES already mention checking the signature:
http://www.gentoo.org/doc/en/handbook/handbook-x86.xml?part=1&chap=2#doc_chap3

Also opened another bug for correcting keys.
https://bugs.gentoo.org/show_bug.cgi?id=386477

-- 
Robin Hugh Johnson
Gentoo Linux: Developer, Trustee & Infrastructure Lead
E-Mail     : robbat2@gentoo.org
GnuPG FP   : 11AC BA4F 4778 E3F6 E4ED  F38E B27B 944E 3488 4E85

Re: [gentoo-dev] integrity of stage files

[Matt Turner]

On Sat, Oct 8, 2011 at 6:43 PM, Robin H. Johnson <robbat2@gentoo.org> wrote:
> On Sat, Oct 08, 2011 at 02:45:02PM -0700, "Paweł Hajdan, Jr." wrote:
>> I checked
>> <http://www.gentoo.org/doc/en/handbook/handbook-x86.xml?part=1&chap=5>
>> and the Handbook only mentions validating MD5 checksums.
>>
>> There are two possible issues:
>>
>> 1. Why are we using _only_ MD5 and SHA1 as the checksums? Shouldn't we
>> be using something stronger?
> Fixed in Catalyst now.
> http://git.overlays.gentoo.org/gitweb/?p=proj/catalyst.git;a=commit;h=42b4f6608682cf03954918ecce7923330a1656fe
> So when the stagebuilders update their Catalyst, they will be generated
> with newer hashes.

Well, almost.

The changes you made are in the master branch (for catalyst-3), but
since catalyst-3 isn't really going anywhere fast, you should
cherry-pick your patches back to the catalyst_2 branch so they'll be
available in the next 2.0.6.919 release.

Matt

Re: [gentoo-dev] integrity of stage files

[Robin H. Johnson]

On Sat, Oct 08, 2011 at 08:21:44PM -0400, Matt Turner wrote:
> On Sat, Oct 8, 2011 at 6:43 PM, Robin H. Johnson <robbat2@gentoo.org> wrote:
> > On Sat, Oct 08, 2011 at 02:45:02PM -0700, "Paweł Hajdan, Jr." wrote:
> >> I checked
> >> <http://www.gentoo.org/doc/en/handbook/handbook-x86.xml?part=1&chap=5>
> >> and the Handbook only mentions validating MD5 checksums.
> >>
> >> There are two possible issues:
> >>
> >> 1. Why are we using _only_ MD5 and SHA1 as the checksums? Shouldn't we
> >> be using something stronger?
> > Fixed in Catalyst now.
> > http://git.overlays.gentoo.org/gitweb/?p=proj/catalyst.git;a=commit;h=42b4f6608682cf03954918ecce7923330a1656fe
> > So when the stagebuilders update their Catalyst, they will be generated
> > with newer hashes.
> 
> Well, almost.
> 
> The changes you made are in the master branch (for catalyst-3), but
> since catalyst-3 isn't really going anywhere fast, you should
> cherry-pick your patches back to the catalyst_2 branch so they'll be
> available in the next 2.0.6.919 release.
Done already.

-- 
Robin Hugh Johnson
Gentoo Linux: Developer, Trustee & Infrastructure Lead
E-Mail     : robbat2@gentoo.org
GnuPG FP   : 11AC BA4F 4778 E3F6 E4ED  F38E B27B 944E 3488 4E85

Re: [gentoo-dev] integrity of stage files

["Paweł Hajdan, Jr."]

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On 10/8/11 5:01 PM, Robin H. Johnson wrote:
>> Ah, I just forgot about that page. Okay, so can we also update the
>> Handbook to include GPG signature checking?
> It DOES already mention checking the signature:
> http://www.gentoo.org/doc/en/handbook/handbook-x86.xml?part=1&chap=2#doc_chap3

That's good, but it only mentions GPG for checking downloaded .iso
images. GPG is not mentioned at all for stage files.

For example, I don't re-download the installation .iso very often (old
ones are still good, or one can use sysresccd), but I always re-download
the most recent stages (less rebuilding).


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Re: [gentoo-dev] integrity of stage files

[Alec Warner]

On Sat, Oct 8, 2011 at 5:41 PM, "Paweł Hajdan, Jr."
<phajdan.jr@gentoo.org> wrote:
> On 10/8/11 5:01 PM, Robin H. Johnson wrote:
>>> Ah, I just forgot about that page. Okay, so can we also update the
>>> Handbook to include GPG signature checking?
>> It DOES already mention checking the signature:
>> http://www.gentoo.org/doc/en/handbook/handbook-x86.xml?part=1&chap=2#doc_chap3
>
> That's good, but it only mentions GPG for checking downloaded .iso
> images. GPG is not mentioned at all for stage files.
>
> For example, I don't re-download the installation .iso very often (old
> ones are still good, or one can use sysresccd), but I always re-download
> the most recent stages (less rebuilding).
>
>

Why not ship something in /usr/portage/scripts, or write some scripts
to do this?

-A

Re: [gentoo-dev] integrity of stage files

[Robin H. Johnson]

On Sat, Oct 08, 2011 at 05:44:01PM -0700, Alec Warner wrote:
> On Sat, Oct 8, 2011 at 5:41 PM, "Paweł Hajdan, Jr."
> <phajdan.jr@gentoo.org> wrote:
> > On 10/8/11 5:01 PM, Robin H. Johnson wrote:
> >>> Ah, I just forgot about that page. Okay, so can we also update the
> >>> Handbook to include GPG signature checking?
> >> It DOES already mention checking the signature:
> >> http://www.gentoo.org/doc/en/handbook/handbook-x86.xml?part=1&chap=2#doc_chap3
> >
> > That's good, but it only mentions GPG for checking downloaded .iso
> > images. GPG is not mentioned at all for stage files.
> >
> > For example, I don't re-download the installation .iso very often (old
> > ones are still good, or one can use sysresccd), but I always re-download
> > the most recent stages (less rebuilding).
> Why not ship something in /usr/portage/scripts, or write some scripts
> to do this?
+1 on having scripts, but they need to be in the media, not the scripts
dir.

-- 
Robin Hugh Johnson
Gentoo Linux: Developer, Trustee & Infrastructure Lead
E-Mail     : robbat2@gentoo.org
GnuPG FP   : 11AC BA4F 4778 E3F6 E4ED  F38E B27B 944E 3488 4E85