[gentoo-dev] [News item review] Portage rsync tree verification

[gentoo-dev] [News item review] Portage rsync tree verification

[Michał Górny]

Hi,

This one would be committed once new sys-apps/portage release is wrapped
up and hits ~arch.

---
Title: Portage rsync tree verification
Author: Michał Górny <mgorny@gentoo.org>
Posted: 2018-01-xx
Revision: 1
News-Item-Format: 2.0
Display-If-Installed: <sys-apps/portage-2.3.21

Starting with sys-apps/portage-2.3.22, Portage enables strong
cryptographic verification of the Gentoo rsync tree by default.
This aims to prevent malicious third parties from altering the contents
of the ebuild repository received by our users.

The verification is implemented using app-portage/gemato. Currently,
the whole repository is verified after syncing. On systems with slow
hard drives, this could take around 2 minutes. If you wish to disable
it, you can disable the 'rsync-verify' flag on sys-apps/portage
or set 'sync-rsync-verify-metamanifest = no' in your repos.conf.

Please note that the verification currently does not prevent Portage
from using the repository after syncing. If 'emerge --sync' fails,
do not install any packages and retry syncing. In case of prolonged
or frequent verification failures, please make sure to report a bug
including the failing mirror addresses (found in emerge.log).

The verification uses keys provided by the app-crypt/gentoo-keys
package. The keys are refreshed from the keyserver before every use
in order to check for revocation. The post-sync verification ensures
that the key package is verified itself. However, manual verification
is required before the first use.

On new Gentoo installations including portage-2.3.22, the verification
of the keys will be covered by verifying the installation media
and repository snapshot signatures. On existing installations, you need
to manually compare the primary key fingerprint (reported by gemato
on every sync) against the official Gentoo keys [1]. An example gemato
output is:

  INFO:root:Valid OpenPGP signature found:
  INFO:root:- primary key: 1234567890ABCDEF1234567890ABCDEF12345678
  INFO:root:- subkey: FEDCBA0987654321FEDCBA0987654321FEDCBA09

The primary key printed must match 'Gentoo Portage Snapshot Signing Key'
on the site. Please make sure to also check the certificate used
for the secure connection to the site!

[1]:https://www.gentoo.org/downloads/signatures/
---

-- 
Best regards,
Michał Górny

[gentoo-dev] Re: [News item review] Portage rsync tree verification

[Duncan]

Michał Górny posted on Thu, 25 Jan 2018 11:04:27 +0100 as excerpted:

> Hi,
> 
> This one would be committed once new sys-apps/portage release is wrapped
> up and hits ~arch.
> 
> ---
> Title: Portage rsync tree verification

Might want to put a paragraph in there saying git sync users can ignore, 
or how they can get gpg signature verification as well if its possible. 
(Sufficient to just link it if it's more involved than a single 
paragraph, since this is primarily for rsync users.)

-- 
Duncan - List replies preferred.   No HTML msgs.
"Every nonfree program has a lord, a master --
and if you use the program, he is your master."  Richard Stallman

Re: [gentoo-dev] [News item review] Portage rsync tree verification

[Kristian Fiskerstrand]

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On 01/25/2018 11:04 AM, Michał Górny wrote:
> Hi,
> 

Thanks for your work on this!

> This one would be committed once new sys-apps/portage release is
> wrapped up and hits ~arch.
> 
> --- Title: Portage rsync tree verification Author: Michał Górny
> <mgorny@gentoo.org> Posted: 2018-01-xx Revision: 1 News-Item-Format:
> 2.0 Display-If-Installed: <sys-apps/portage-2.3.21
> 
> Starting with sys-apps/portage-2.3.22, Portage enables strong
> cryptographic verification of the Gentoo rsync tree by default. This
> aims to prevent malicious third parties from altering the contents of
> the ebuild repository received by our users.

Just for sake of it, would remove "strong" here, as it is a description
and not PR document. Should we be consistent with referencing, so e.g
the Gentoo ebuild repository as distributed through rsync, or something?
Atm we seem to be using different terms all of the place, so should try
to harmonize a bit.

> 
> The verification is implemented using app-portage/gemato. Currently, 

... "implemented in", as opposed to "using"? its implemented using
various cryptographic primitives, but gemato is the implementation
itself of sorts.

> the whole repository is verified after syncing. On systems with slow 
> hard drives, this could take around 2 minutes. If you wish to
> disable it, you can disable the 'rsync-verify' flag on

USE flag?

> sys-apps/portage or set 'sync-rsync-verify-metamanifest = no' in your
> repos.conf.
> 
> Please note that the verification currently does not prevent Portage 
> from using the repository after syncing. If 'emerge --sync' fails, do
> not install any packages and retry syncing. In case of prolonged or
> frequent verification failures, please make sure to report a bug 
> including the failing mirror addresses (found in emerge.log).
> 
> The verification uses keys provided by the app-crypt/gentoo-keys 
> package. The keys are refreshed from the keyserver before every use 
> in order to check for revocation. The post-sync verification ensures 
> that the key package is verified itself. However, manua
> verification is required before the first use.

Maybe some wording around binary keyring? e.g the verification uses
information from the binary keyring provided by app-crypt/gentoo-keys?
In particular the reference to "key package" might be misread (and the
keyring consists of multiple public keyblocks, that includes much more
information than the cryptographic keys per se)

> 
> On new Gentoo installations including portage-2.3.22, the

stage3s?

> verification of the keys will be covered by verifying the
> installation media and repository snapshot signatures. On existing
> installations, you need to manually compare the primary key
> fingerprint (reported by gemato on every sync) against the official
> Gentoo keys [1]. An example gemato output is:
> 
> INFO:root:Valid OpenPGP signature found: INFO:root:- primary key:
> 1234567890ABCDEF1234567890ABCDEF12345678 INFO:root:- subkey:
> FEDCBA0987654321FEDCBA0987654321FEDCBA09
> 
> The primary key printed must match 'Gentoo Portage Snapshot Signing
> Key' on the site. Please make sure to also check the certificate
> used for the secure connection to the site!
> 
> [1]:https://www.gentoo.org/downloads/signatures/ ---
> 


-- 
Kristian Fiskerstrand
OpenPGP keyblock reachable at hkp://pool.sks-keyservers.net
fpr:94CB AFDD 3034 5109 5618 35AA 0B7F 8B60 E3ED FAE3


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Re: [gentoo-dev] [News item review] Portage rsync tree verification

[Michał Górny]

W dniu czw, 25.01.2018 o godzinie 12∶01 +0100, użytkownik Kristian
Fiskerstrand napisał:
> On 01/25/2018 11:04 AM, Michał Górny wrote:
> > Hi,
> > 
> 
> Thanks for your work on this!
> 
> > This one would be committed once new sys-apps/portage release is
> > wrapped up and hits ~arch.
> > 
> > --- Title: Portage rsync tree verification Author: Michał Górny
> > <mgorny@gentoo.org> Posted: 2018-01-xx Revision: 1 News-Item-Format:
> > 2.0 Display-If-Installed: <sys-apps/portage-2.3.21
> > 
> > Starting with sys-apps/portage-2.3.22, Portage enables strong
> > cryptographic verification of the Gentoo rsync tree by default. This
> > aims to prevent malicious third parties from altering the contents of
> > the ebuild repository received by our users.
> 
> Just for sake of it, would remove "strong" here, as it is a description
> and not PR document. Should we be consistent with referencing, so e.g
> the Gentoo ebuild repository as distributed through rsync, or something?
> Atm we seem to be using different terms all of the place, so should try
> to harmonize a bit.

Done.

> 
> > 
> > The verification is implemented using app-portage/gemato. Currently, 
> 
> ... "implemented in", as opposed to "using"? its implemented using
> various cryptographic primitives, but gemato is the implementation
> itself of sorts.

It was supposed to mean that Portage currently uses gemato to
do the verification. 'via using' maybe?

> 
> > the whole repository is verified after syncing. On systems with slow 
> > hard drives, this could take around 2 minutes. If you wish to
> > disable it, you can disable the 'rsync-verify' flag on
> 
> USE flag?

Done.

> 
> > sys-apps/portage or set 'sync-rsync-verify-metamanifest = no' in your
> > repos.conf.
> > 
> > Please note that the verification currently does not prevent Portage 
> > from using the repository after syncing. If 'emerge --sync' fails, do
> > not install any packages and retry syncing. In case of prolonged or
> > frequent verification failures, please make sure to report a bug 
> > including the failing mirror addresses (found in emerge.log).
> > 
> > The verification uses keys provided by the app-crypt/gentoo-keys 
> > package. The keys are refreshed from the keyserver before every use 
> > in order to check for revocation. The post-sync verification ensures 
> > that the key package is verified itself. However, manua
> > verification is required before the first use.
> 
> Maybe some wording around binary keyring? e.g the verification uses
> information from the binary keyring provided by app-crypt/gentoo-keys?
> In particular the reference to "key package" might be misread (and the
> keyring consists of multiple public keyblocks, that includes much more
> information than the cryptographic keys per se)

Done.

> 
> > 
> > On new Gentoo installations including portage-2.3.22, the
> 
> stage3s?

Nah. I need to think how to word it properly. It's about installations
that are created from new stages.

> 
> > verification of the keys will be covered by verifying the
> > installation media and repository snapshot signatures. On existing
> > installations, you need to manually compare the primary key
> > fingerprint (reported by gemato on every sync) against the official
> > Gentoo keys [1]. An example gemato output is:
> > 
> > INFO:root:Valid OpenPGP signature found: INFO:root:- primary key:
> > 1234567890ABCDEF1234567890ABCDEF12345678 INFO:root:- subkey:
> > FEDCBA0987654321FEDCBA0987654321FEDCBA09
> > 
> > The primary key printed must match 'Gentoo Portage Snapshot Signing
> > Key' on the site. Please make sure to also check the certificate
> > used for the secure connection to the site!
> > 
> > [1]:https://www.gentoo.org/downloads/signatures/ ---
> > 
> 
> 

-- 
Best regards,
Michał Górny

Re: [gentoo-dev] [News item review] Portage rsync tree verification

[M. J. Everitt]

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On 25/01/18 11:01, Kristian Fiskerstrand wrote:
> On 01/25/2018 11:04 AM, Michał Górny wrote:
>
>> The verification is implemented using app-portage/gemato. Currently, 
> ... "implemented in", as opposed to "using"? its implemented using
> various cryptographic primitives, but gemato is the implementation
> itself of sorts.
>
>
<nitpick>
"implemented with gemato" ?
</nitpick>


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Re: [gentoo-dev] [News item review] Portage rsync tree verification (v2)

[Michał Górny]

Here's the updated version:

---
Title: Portage rsync tree verification
Author: Michał Górny <mgorny@gentoo.org>
Posted: 2018-01-xx
Revision: 1
News-Item-Format: 2.0
Display-If-Installed: <sys-apps/portage-2.3.21

Starting with sys-apps/portage-2.3.22, Portage enables cryptographic
verification of the Gentoo rsync repository distributed over rsync
by default. This aims to prevent malicious third parties from altering
the contents of the ebuild repository received by our users.

This does not affect users syncing using git and other methods.
Appropriate verification mechanisms for them will be provided
in the future.

The verification is implemented via using app-portage/gemato. Currently,
the whole repository is verified after syncing. On systems with slow
hard drives, this could take around 2 minutes. If you wish to disable
it, you can disable the 'rsync-verify' USE flag on sys-apps/portage
or set 'sync-rsync-verify-metamanifest = no' in your repos.conf.

Please note that the verification currently does not prevent Portage
from using the repository after syncing. If 'emerge --sync' fails,
do not install any packages and retry syncing. In case of prolonged
or frequent verification failures, please make sure to report a bug
including the failing mirror addresses (found in emerge.log).

The verification uses information from the binary keyring provided
by the app-crypt/gentoo-keys package. The keys are refreshed
from the keyserver before every use in order to check for revocation.
The post-sync verification ensures that the key package is verified
itself. However, manual verification is required before the first use.

On Gentoo installations created using installation media that included
portage-2.3.22, the keys will already be covered by the installation
media signatures. On existing installations, you need to manually
compare the primary key fingerprint (reported by gemato on every sync)
against the official Gentoo keys [1]. An example gemato output is:

  INFO:root:Valid OpenPGP signature found:
  INFO:root:- primary key: 1234567890ABCDEF1234567890ABCDEF12345678
  INFO:root:- subkey: FEDCBA0987654321FEDCBA0987654321FEDCBA09

The primary key printed must match 'Gentoo Portage Snapshot Signing Key'
on the site. Please make sure to also check the certificate used
for the secure connection to the site!

[1]:https://www.gentoo.org/downloads/signatures/
---

-- 
Best regards,
Michał Górny

Re: [gentoo-dev] [News item review] Portage rsync tree verification (v2)

[Aaron W. Swenson]

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On 2018-01-25 13:35, Michał Górny wrote:
> Display-If-Installed: <sys-apps/portage-2.3.21

Don't we want to tell people using >=2.3.22 this same information?

I know we don’t have expires, yet. How about making it
<sys-apps/portage-2.3.30?

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Re: [gentoo-dev] [News item review] Portage rsync tree verification (v2)

[Ulrich Mueller]

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>>>>> On Thu, 25 Jan 2018, Michał Górny wrote:

> Here's the updated version:
> ---

> Starting with sys-apps/portage-2.3.22, Portage enables cryptographic
> verification of the Gentoo rsync repository distributed over rsync
> by default.

Looks like there's one "rsync" too much in that sentence.

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Re: [gentoo-dev] [News item review] Portage rsync tree verification (v2)

[Robin H. Johnson]

On Thu, Jan 25, 2018 at 01:35:17PM +0100, Michał Górny wrote:
> Title: Portage rsync tree verification
> Author: Michał Górny <mgorny@gentoo.org>
> Posted: 2018-01-xx
> Revision: 1
> News-Item-Format: 2.0
> Display-If-Installed: <sys-apps/portage-2.3.21
Drop Display-If-Installed, they need to always see this until they know
it was bootstrapped.

> Starting with sys-apps/portage-2.3.22, Portage enables cryptographic
> verification of the Gentoo rsync repository distributed over rsync
> by default. 
Seems very wordy, suggested cleanup:
|| Starting with sys-apps/portage-2.3.22, Portage will verify the Gentoo
|| repository after rsync by default.

> This aims to prevent malicious third parties from altering
> the contents of the ebuild repository received by our users.
> 
> This does not affect users syncing using git and other methods.
> Appropriate verification mechanisms for them will be provided
> in the future.
Note that emerge-webrsync has verification via FEATURES=webrsync-gpg?

Rewrite:
|| The new verification is intended for users who syncing via rsync.
|| Users who sync by emerge-webrsync should see [linkref]. 
|| Verification mechanisms for other methods of sync will be provided in
|| future.


> On Gentoo installations created using installation media that included
> portage-2.3.22, the keys will already be covered by the installation
> media signatures. On existing installations, you need to manually
> compare the primary key fingerprint (reported by gemato on every sync)
> against the official Gentoo keys [1]. An example gemato output is:
>   INFO:root:Valid OpenPGP signature found:
>   INFO:root:- primary key: 1234567890ABCDEF1234567890ABCDEF12345678
>   INFO:root:- subkey: FEDCBA0987654321FEDCBA0987654321FEDCBA09
Either we should use real key here, or specifically note this is a fake
key output on purpose.

-- 
Robin Hugh Johnson
Gentoo Linux: Dev, Infra Lead, Foundation Treasurer
E-Mail   : robbat2@gentoo.org
GnuPG FP : 11ACBA4F 4778E3F6 E4EDF38E B27B944E 34884E85
GnuPG FP : 7D0B3CEB E9B85B1F 825BCECF EE05E6F6 A48F6136

Re: [gentoo-dev] [News item review] Portage rsync tree verification (v2)

[Michał Górny]

W dniu czw, 25.01.2018 o godzinie 21∶37 +0000, użytkownik Robin H.
Johnson napisał:
> On Thu, Jan 25, 2018 at 01:35:17PM +0100, Michał Górny wrote:
> > Title: Portage rsync tree verification
> > Author: Michał Górny <mgorny@gentoo.org>
> > Posted: 2018-01-xx
> > Revision: 1
> > News-Item-Format: 2.0
> > Display-If-Installed: <sys-apps/portage-2.3.21
> 
> Drop Display-If-Installed, they need to always see this until they know
> it was bootstrapped.

Well, the idea was that if someone starts with stage that has >2.3.21,
then he has bootstrapped via verifying the stage signature.

> > Starting with sys-apps/portage-2.3.22, Portage enables cryptographic
> > verification of the Gentoo rsync repository distributed over rsync
> > by default. 
> 
> Seems very wordy, suggested cleanup:
> > > Starting with sys-apps/portage-2.3.22, Portage will verify the Gentoo
> > > repository after rsync by default.
> > This aims to prevent malicious third parties from altering
> > the contents of the ebuild repository received by our users.
> > 
> > This does not affect users syncing using git and other methods.
> > Appropriate verification mechanisms for them will be provided
> > in the future.
> 
> Note that emerge-webrsync has verification via FEATURES=webrsync-gpg?

I'm sorry, I have never used that. Does it cover full key maintenance
or rely on user to do the gpg work?

> 
> Rewrite:
> > > The new verification is intended for users who syncing via rsync.
> > > Users who sync by emerge-webrsync should see [linkref]. 
> > > Verification mechanisms for other methods of sync will be provided in
> > > future.
> 
> 
> > On Gentoo installations created using installation media that included
> > portage-2.3.22, the keys will already be covered by the installation
> > media signatures. On existing installations, you need to manually
> > compare the primary key fingerprint (reported by gemato on every sync)
> > against the official Gentoo keys [1]. An example gemato output is:
> >   INFO:root:Valid OpenPGP signature found:
> >   INFO:root:- primary key: 1234567890ABCDEF1234567890ABCDEF12345678
> >   INFO:root:- subkey: FEDCBA0987654321FEDCBA0987654321FEDCBA09
> 
> Either we should use real key here, or specifically note this is a fake
> key output on purpose.

Well, I've assumed most people would be able to figure out that it would
be quite a coincidence to see such a key id. I wanted to avoid putting
the real id so that people would actually check that HTTPS site instead
of relying on the security of news item delivery.

Will send an updated version tomorrow.

-- 
Best regards,
Michał Górny

Re: [gentoo-dev] [News item review] Portage rsync tree verification (v2)

[R0b0t1]

On Thu, Jan 25, 2018 at 3:45 PM, Michał Górny <mgorny@gentoo.org> wrote:
> W dniu czw, 25.01.2018 o godzinie 21∶37 +0000, użytkownik Robin H.
> Johnson napisał:
>> On Thu, Jan 25, 2018 at 01:35:17PM +0100, Michał Górny wrote:
>> > Title: Portage rsync tree verification
>> > Author: Michał Górny <mgorny@gentoo.org>
>> > Posted: 2018-01-xx
>> > Revision: 1
>> > News-Item-Format: 2.0
>> > Display-If-Installed: <sys-apps/portage-2.3.21
>>
>> Drop Display-If-Installed, they need to always see this until they know
>> it was bootstrapped.
>
> Well, the idea was that if someone starts with stage that has >2.3.21,
> then he has bootstrapped via verifying the stage signature.
>
>> > Starting with sys-apps/portage-2.3.22, Portage enables cryptographic
>> > verification of the Gentoo rsync repository distributed over rsync
>> > by default.
>>
>> Seems very wordy, suggested cleanup:
>> > > Starting with sys-apps/portage-2.3.22, Portage will verify the Gentoo
>> > > repository after rsync by default.
>> > This aims to prevent malicious third parties from altering
>> > the contents of the ebuild repository received by our users.
>> >
>> > This does not affect users syncing using git and other methods.
>> > Appropriate verification mechanisms for them will be provided
>> > in the future.
>>
>> Note that emerge-webrsync has verification via FEATURES=webrsync-gpg?
>
> I'm sorry, I have never used that. Does it cover full key maintenance
> or rely on user to do the gpg work?
>

It used to be necessary to set up a GnuPG home for portage and pull
the keys in, but now users can emerge app-crypt/gentoo-keys and set
PORTAGE_GPG_DIR="/var/lib/gentoo/gkeys/keyrings/gentoo/release".

>>
>> Rewrite:
>> > > The new verification is intended for users who syncing via rsync.
>> > > Users who sync by emerge-webrsync should see [linkref].
>> > > Verification mechanisms for other methods of sync will be provided in
>> > > future.
>>
>>
>> > On Gentoo installations created using installation media that included
>> > portage-2.3.22, the keys will already be covered by the installation
>> > media signatures. On existing installations, you need to manually
>> > compare the primary key fingerprint (reported by gemato on every sync)
>> > against the official Gentoo keys [1]. An example gemato output is:
>> >   INFO:root:Valid OpenPGP signature found:
>> >   INFO:root:- primary key: 1234567890ABCDEF1234567890ABCDEF12345678
>> >   INFO:root:- subkey: FEDCBA0987654321FEDCBA0987654321FEDCBA09
>>
>> Either we should use real key here, or specifically note this is a fake
>> key output on purpose.
>
> Well, I've assumed most people would be able to figure out that it would
> be quite a coincidence to see such a key id. I wanted to avoid putting
> the real id so that people would actually check that HTTPS site instead
> of relying on the security of news item delivery.
>
> Will send an updated version tomorrow.
>
> --
> Best regards,
> Michał Górny
>
>

Re: [gentoo-dev] [News item review] Portage rsync tree verification (v2)

[Michał Górny]

W dniu czw, 25.01.2018 o godzinie 15∶55 -0600, użytkownik R0b0t1
napisał:
> On Thu, Jan 25, 2018 at 3:45 PM, Michał Górny <mgorny@gentoo.org> wrote:
> > W dniu czw, 25.01.2018 o godzinie 21∶37 +0000, użytkownik Robin H.
> > Johnson napisał:
> > > On Thu, Jan 25, 2018 at 01:35:17PM +0100, Michał Górny wrote:
> > > > Title: Portage rsync tree verification
> > > > Author: Michał Górny <mgorny@gentoo.org>
> > > > Posted: 2018-01-xx
> > > > Revision: 1
> > > > News-Item-Format: 2.0
> > > > Display-If-Installed: <sys-apps/portage-2.3.21
> > > 
> > > Drop Display-If-Installed, they need to always see this until they know
> > > it was bootstrapped.
> > 
> > Well, the idea was that if someone starts with stage that has >2.3.21,
> > then he has bootstrapped via verifying the stage signature.
> > 
> > > > Starting with sys-apps/portage-2.3.22, Portage enables cryptographic
> > > > verification of the Gentoo rsync repository distributed over rsync
> > > > by default.
> > > 
> > > Seems very wordy, suggested cleanup:
> > > > > Starting with sys-apps/portage-2.3.22, Portage will verify the Gentoo
> > > > > repository after rsync by default.
> > > > 
> > > > This aims to prevent malicious third parties from altering
> > > > the contents of the ebuild repository received by our users.
> > > > 
> > > > This does not affect users syncing using git and other methods.
> > > > Appropriate verification mechanisms for them will be provided
> > > > in the future.
> > > 
> > > Note that emerge-webrsync has verification via FEATURES=webrsync-gpg?
> > 
> > I'm sorry, I have never used that. Does it cover full key maintenance
> > or rely on user to do the gpg work?
> > 
> 
> It used to be necessary to set up a GnuPG home for portage and pull
> the keys in, but now users can emerge app-crypt/gentoo-keys and set
> PORTAGE_GPG_DIR="/var/lib/gentoo/gkeys/keyrings/gentoo/release".
> 

In that case I'd rather not announce it until it is integrated properly.

-- 
Best regards,
Michał Górny

Re: [gentoo-dev] [News item review] Portage rsync tree verification (v2)

[R0b0t1]

On Sat, Jan 27, 2018 at 8:27 AM, Michał Górny <mgorny@gentoo.org> wrote:
> W dniu czw, 25.01.2018 o godzinie 15∶55 -0600, użytkownik R0b0t1
> napisał:
>> On Thu, Jan 25, 2018 at 3:45 PM, Michał Górny <mgorny@gentoo.org> wrote:
>> > W dniu czw, 25.01.2018 o godzinie 21∶37 +0000, użytkownik Robin H.
>> > Johnson napisał:
>> > > On Thu, Jan 25, 2018 at 01:35:17PM +0100, Michał Górny wrote:
>> > > > Title: Portage rsync tree verification
>> > > > Author: Michał Górny <mgorny@gentoo.org>
>> > > > Posted: 2018-01-xx
>> > > > Revision: 1
>> > > > News-Item-Format: 2.0
>> > > > Display-If-Installed: <sys-apps/portage-2.3.21
>> > >
>> > > Drop Display-If-Installed, they need to always see this until they know
>> > > it was bootstrapped.
>> >
>> > Well, the idea was that if someone starts with stage that has >2.3.21,
>> > then he has bootstrapped via verifying the stage signature.
>> >
>> > > > Starting with sys-apps/portage-2.3.22, Portage enables cryptographic
>> > > > verification of the Gentoo rsync repository distributed over rsync
>> > > > by default.
>> > >
>> > > Seems very wordy, suggested cleanup:
>> > > > > Starting with sys-apps/portage-2.3.22, Portage will verify the Gentoo
>> > > > > repository after rsync by default.
>> > > >
>> > > > This aims to prevent malicious third parties from altering
>> > > > the contents of the ebuild repository received by our users.
>> > > >
>> > > > This does not affect users syncing using git and other methods.
>> > > > Appropriate verification mechanisms for them will be provided
>> > > > in the future.
>> > >
>> > > Note that emerge-webrsync has verification via FEATURES=webrsync-gpg?
>> >
>> > I'm sorry, I have never used that. Does it cover full key maintenance
>> > or rely on user to do the gpg work?
>> >
>>
>> It used to be necessary to set up a GnuPG home for portage and pull
>> the keys in, but now users can emerge app-crypt/gentoo-keys and set
>> PORTAGE_GPG_DIR="/var/lib/gentoo/gkeys/keyrings/gentoo/release".
>>
>
> In that case I'd rather not announce it until it is integrated properly.
>

What is "properly?" It's referenced in the handbook.

Cheers,
     R0b0t1

Re: [gentoo-dev] [News item review] Portage rsync tree verification (v2)

[Alon Bar-Lev]

Hi,

On 25 January 2018 at 14:35, Michał Górny <mgorny@gentoo.org> wrote:
>
> Starting with sys-apps/portage-2.3.22, Portage enables cryptographic
> verification of the Gentoo rsync repository distributed over rsync
> by default. This aims to prevent malicious third parties from altering
> the contents of the ebuild repository received by our users.

<snip>

I did not looked into the detailed implementation, however, please
make sure integrity check handles the same cases we have applied to
emerge-webrsync in the past, including:
1. Fast forward only in time, this is required to avoid hacker to
redirect into older portage to install vulnerabilities that were
approved at that time.
2. Content integrity, especially removal, as far as I understand, the
mechanism will not enable to detect authorized removal of content.

Regards,
Alon

Re: [gentoo-dev] [News item review] Portage rsync tree verification (v2)

[Robin H. Johnson]

[-- Attachment #1: Type: text/plain, Size: 1096 bytes --]

On Thu, Jan 25, 2018 at 11:55:58PM +0200, Alon Bar-Lev wrote:
> I did not looked into the detailed implementation, however, please
> make sure integrity check handles the same cases we have applied to
> emerge-webrsync in the past, including:
Gemato is the implementation of GLEP74/MetaManifest, which DOES
explicitly address both of these concerns.

> 1. Fast forward only in time, this is required to avoid hacker to
> redirect into older portage to install vulnerabilities that were
> approved at that time.
Replay attacks per #1 are addressed via TIMESTAMP field in MetaManifest.

> 2. Content integrity, especially removal, as far as I understand, the
> mechanism will not enable to detect authorized removal of content.
I think you meant 'unauthorized' rather than 'authorized' here.
It will detect files that are expected to exist but are missing.

-- 
Robin Hugh Johnson
Gentoo Linux: Dev, Infra Lead, Foundation Treasurer
E-Mail   : robbat2@gentoo.org
GnuPG FP : 11ACBA4F 4778E3F6 E4EDF38E B27B944E 34884E85
GnuPG FP : 7D0B3CEB E9B85B1F 825BCECF EE05E6F6 A48F6136

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Re: [gentoo-dev] [News item review] Portage rsync tree verification (v2)

[Alon Bar-Lev]

On 26 January 2018 at 00:21, Robin H. Johnson <robbat2@gentoo.org> wrote:
> On Thu, Jan 25, 2018 at 11:55:58PM +0200, Alon Bar-Lev wrote:
>> I did not looked into the detailed implementation, however, please
>> make sure integrity check handles the same cases we have applied to
>> emerge-webrsync in the past, including:
> Gemato is the implementation of GLEP74/MetaManifest, which DOES
> explicitly address both of these concerns.

Good!
Thanks.

>
>> 1. Fast forward only in time, this is required to avoid hacker to
>> redirect into older portage to install vulnerabilities that were
>> approved at that time.
> Replay attacks per #1 are addressed via TIMESTAMP field in MetaManifest.

Interesting, I tried again to understand how it is working without
performing rsync to a temporary directory, compare the timestamp and
reject if unexpected.
Are we doing multiple rsync for the metadata?
Long since I used this insecure rsync...

For me it seems like webrsync and/or squashfs are much easier/faster
to apply integrity into than rsync... :)

Regards,
Alon

Re: [gentoo-dev] [News item review] Portage rsync tree verification (v3)

[Michał Górny]

Next round:

Title: Portage rsync tree verification
Author: Michał Górny <mgorny@gentoo.org>
Posted: 2018-01-xx
Revision: 1
News-Item-Format: 2.0
Display-If-Installed: sys-apps/portage

Starting with sys-apps/portage-2.3.22, Portage will verify the Gentoo
repository after rsync by default.

The new verification is intended for users who syncing via rsync.
Verification mechanisms for other methods of sync will be provided
in future.

This does not affect users syncing using git and other methods.
Appropriate verification mechanisms for them will be provided
in the future.

The verification is implemented via using app-portage/gemato. Currently,
the whole repository is verified after syncing. On systems with slow
hard drives, this could take around 2 minutes. If you wish to disable
it, you can disable the 'rsync-verify' USE flag on sys-apps/portage
or set 'sync-rsync-verify-metamanifest = no' in your repos.conf.

Please note that the verification currently does not prevent Portage
from using the repository after syncing. If 'emerge --sync' fails,
do not install any packages and retry syncing. In case of prolonged
or frequent verification failures, please make sure to report a bug
including the failing mirror addresses (found in emerge.log).

The verification uses information from the binary keyring provided
by the app-crypt/gentoo-keys package. The keys are refreshed
from the keyserver before every use in order to check for revocation.
The post-sync verification ensures that the key package is verified
itself. However, manual verification is required before the first use.

On Gentoo installations created using installation media that included
portage-2.3.22, the keys will already be covered by the installation
media signatures. On existing installations, you need to manually
compare the primary key fingerprint (reported by gemato on every sync)
against the official Gentoo keys [1]. An example gemato output is:

  INFO:root:Valid OpenPGP signature found:
  INFO:root:- primary key: 1234567890ABCDEF1234567890ABCDEF12345678
  INFO:root:- subkey: FEDCBA0987654321FEDCBA0987654321FEDCBA09

Please note that the above snippet does not include the real key id
on purpose. The primary key actually printed by gemato must match
the 'Gentoo Portage Snapshot Signing Key' on the website. Please make
sure to also check the certificate used for the secure connection
to the site!

[1]:https://www.gentoo.org/downloads/signatures/

-- 
Best regards,
Michał Górny

Re: [gentoo-dev] [News item review] Portage rsync tree verification (v3)

[M. J. Everitt]

[-- Attachment #1.1: Type: text/plain, Size: 341 bytes --]

On 27/01/18 14:26, Michał Górny wrote [excerpted]:
> The verification is implemented via using app-portage/gemato. Currently,
> the whole repository is verified after syncing.
>
I would drop either 'via' or 'using' - they both are the same
verb/meaning and one is hence redundant.
Just my 2c as a native English speaker :)

MJE


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[gentoo-dev] Re: [News item review] Portage rsync tree verification (v3)

[Duncan]

Michał Górny posted on Sat, 27 Jan 2018 15:26:44 +0100 as excerpted:

> The new verification is intended for users who syncing via rsync.
> Verification mechanisms for other methods of sync will be provided in
> future.


s/in future/in the future/

Thanks for adding that paragraph.  It perfectly addresses the question I 
had about the original. =:^)

-- 
Duncan - List replies preferred.   No HTML msgs.
"Every nonfree program has a lord, a master --
and if you use the program, he is your master."  Richard Stallman

Re: [gentoo-dev] [News item review] Portage rsync tree verification (v3)

[Nils Freydank]

[-- Attachment #1: Type: text/plain, Size: 425 bytes --]

Am Samstag, 27. Januar 2018, 15:26:44 CET schrieb Michał Górny:
> [...]
> 
> The new verification is intended for users who syncing via rsync.
> Verification mechanisms for other methods of sync will be provided
> in future.
s/who syncing/who are syncing/

("who sync via rsync" would sound a bit odd, but should work aswell.)

-- 
GPG fingerprint: '766B 8122 1342 6912 3401 492A 8B54 D7A3 FF3C DB17'
Holgersson

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Re: [gentoo-dev] [News item review] Portage rsync tree verification (v4)

[Michał Górny]

Hopefully the final version.

---
Title: Portage rsync tree verification
Author: Michał Górny <mgorny@gentoo.org>
Posted: 2018-01-xx
Revision: 1
News-Item-Format: 2.0
Display-If-Installed: sys-apps/portage

Starting with sys-apps/portage-2.3.22, Portage will verify the Gentoo
repository after rsync by default.

The new verification is intended for users who are syncing via rsync.
Verification mechanisms for other methods of sync will be provided
in the future.

This does not affect users syncing using git and other methods.
Appropriate verification mechanisms for them will be provided
in the future.

The verification is implemented via app-portage/gemato. Currently,
the whole repository is verified after syncing. On systems with slow
hard drives, this could take around 2 minutes. If you wish to disable
it, you can disable the 'rsync-verify' USE flag on sys-apps/portage
or set 'sync-rsync-verify-metamanifest = no' in your repos.conf.

Please note that the verification currently does not prevent Portage
from using the repository after syncing. If 'emerge --sync' fails,
do not install any packages and retry syncing. In case of prolonged
or frequent verification failures, please make sure to report a bug
including the failing mirror addresses (found in emerge.log).

The verification uses information from the binary keyring provided
by the app-crypt/gentoo-keys package. The keys are refreshed
from the keyserver before every use in order to check for revocation.
The post-sync verification ensures that the key package is verified
itself. However, manual verification is required before the first use.

On Gentoo installations created using installation media that included
portage-2.3.22, the keys will already be covered by the installation
media signatures. On existing installations, you need to manually
compare the primary key fingerprint (reported by gemato on every sync)
against the official Gentoo keys [1]. An example gemato output is:

  INFO:root:Valid OpenPGP signature found:
  INFO:root:- primary key: 1234567890ABCDEF1234567890ABCDEF12345678
  INFO:root:- subkey: FEDCBA0987654321FEDCBA0987654321FEDCBA09

Please note that the above snippet does not include the real key id
on purpose. The primary key actually printed by gemato must match
the 'Gentoo Portage Snapshot Signing Key' on the website. Please make
sure to also check the certificate used for the secure connection
to the site!

[1]:https://www.gentoo.org/downloads/signatures/

-- 
Best regards,
Michał Górny

[gentoo-dev] Re: [News item review] Portage rsync tree verification (v4)

[Duncan]

Michał Górny posted on Sun, 28 Jan 2018 09:58:37 +0100 as excerpted:

> The new verification is intended for users who are syncing via rsync.
> Verification mechanisms for other methods of sync will be provided in
> the future.
> 
> This does not affect users syncing using git and other methods.
> Appropriate verification mechanisms for them will be provided in the
> future.


Sorry I didn't catch this sooner.  Now we have a repeat.  Maybe combine 
the two paragraphs like this:

The new verification is intended for users who are syncing via rsync.  
Users syncing using git or other methods are not affected, and 
verification for them will be provided in the future.

-- 
Duncan - List replies preferred.   No HTML msgs.
"Every nonfree program has a lord, a master --
and if you use the program, he is your master."  Richard Stallman

Re: [gentoo-dev] [News item review] Portage rsync tree verification (v4)

[Andrew Barchuk]

Hi everyone,

> three possible solutions for splitting distfiles were listed:
> 
> a. using initial portion of filename,
> 
> b. using initial portion of file hash,
> 
> c. using initial portion of filename hash.
> 
> The significant advantage of the filename option was simplicity.  With
> that solution, the users could easily determine the correct subdirectory
> themselves.  However, it's significant disadvantage was very uneven
> shuffling of data.  In particular, the TeΧ Live packages alone count
> almost 23500 distfiles and all use a common prefix, making it impossible
> to split them further.
> 
> The alternate option of using file hash has the advantage of having
> a more balanced split.

There's another option to use character ranges for each directory
computed in a way to have the files distributed evenly. One way to do
that is to use filename prefix of dynamic length so that each range
holds the same number of files. E.g. we would have Ab/, Ap/, Ar/ but
texlive-module-te/, texlive-module-th/, texlive-module-ti/. A similar
but simpler option is to use file names as range bounds (the same way
dictionaries use words to demarcate page bounds): each directory will
have a name of the first file located inside. This way files will be
distributed evenly and it's still easy to pick a correct directory where
a file will be located manually.

I have implemented a sketch of distfiles splitting that's using file
names as bounds in Python to demonstrate the idea (excuse possibly
non-idiomatic code, I'm not very versed in Python):

$ cat distfile-dirs.py
#!/usr/bin/env python3

import sys

"""
Builds list of dictionary directories to split the list of input files
into evenly. Each directory has name of the first file that is located
in the directory. Takes number of directories as an argument and reads
list of files from stdin. The resulting list or directories is printed
to stdout.
"""

dir_num = int(sys.argv[1])
distfiles = sys.stdin.read().splitlines()
distfile_num = len(distfiles)
dir_size = distfile_num / dir_num
# allows adding files in the beginning without repartitioning
dirs = ["0"]
next_dir = dir_size
while next_dir < distfile_num:
    dirs.append(distfiles[round(next_dir)])
    next_dir += dir_size
print("/\n".join(dirs) + "/")

$ cat pick-distfiles-dir.py
#!/usr/bin/env python3

"""
Picks the directory for a given file name. Takes a distfile name as an
argument. Reads sorted list of directories from stdin, name of each
directory is assumed to be the name of first file that's located inside.
"""

import sys

distfile = sys.argv[1]
dirs = sys.stdin.read().splitlines()
left = 0
right = len(dirs) - 1
while left < right:
    pivot = round((left + right) / 2)
    if (dirs[pivot] <= distfile):
        left = pivot + 1
    else:
        right = pivot - 1

if distfile < dirs[right]:
    print(dirs[right-1])
else:
    print(dirs[right])

$ # distfiles.txt contains all the distfile names
$ head -n5 distfiles.txt
0CD9CDDE3F56BB5250D87C54592F04CBC24F03BF-wagon-provider-api-2.10.jar
0CE1EDB914C94EBC388F086C6827E8BDEEC71AC2-commons-lang-2.6.jar
0DCC973606CBD9737541AA5F3E76DED6E3F4D0D0-iri.jar
0ad-0.0.22-alpha-unix-build.tar.xz
0ad-0.0.22-alpha-unix-data.tar.xz

$ # calculate 500 directories to split distfiles into evenly
$ cat distfiles.txt | ./distfile-dirs.py 500 > dirs.txt
$ tail -n5 dirs.txt
xrmap-2.29.tar.bz2/
xview-3.2p1.4-18c.tar.gz/
yasat-700.tar.gz/
yubikey-manager-qt-0.4.0.tar.gz/
zimg-2.5.1.tar.gz

$ # pick a directory for xvinfo-1.0.1.tar.bz2
$ cat dirs.txt | ./pick-distfiles-dir.py xvinfo-1.0.1.tar.bz2
xview-3.2p1.4-18c.tar.gz/

Using the approach above the files will distributed evenly among the
directories keeping the possibility to determine the directory for a
specific file by hand. It's possible if necessary to keep the directory
structure unchanged for very long time and it will likely stay
well-balanced. Picking a directory for a file is very cheap. The only
obvious downside I see is that it's necessary to know list of
directories to pick the correct one (can be mitigated by caching the
list of directories if important). If it's desirable to make directory
names shorter or to look less like file names it's fairly easy to
achieve by keeping only unique prefixes of directories. For example:

xrmap-2.29.tar.bz2/
xview-3.2p1.4-18c.tar.gz/
yasat-700.tar.gz/
yubikey-manager-qt-0.4.0.tar.gz/
zimg-2.5.1.tar.gz/

will become

xr/
xv/
ya/
yu/
z/

Thanks for taking time to consider the suggestion.

---
Andrew

Re: [gentoo-dev] [News item review] Portage rsync tree verification (v4)

[Robin H. Johnson]

[-- Attachment #1: Type: text/plain, Size: 2998 bytes --]

On Sun, Jan 28, 2018 at 09:30:31PM +0100, Andrew Barchuk wrote:
> Hi everyone,
> 
> > three possible solutions for splitting distfiles were listed:
> There's another option to use character ranges for each directory
> computed in a way to have the files distributed evenly. One way to do
> that is to use filename prefix of dynamic length so that each range
> holds the same number of files. E.g. we would have Ab/, Ap/, Ar/ but
> texlive-module-te/, texlive-module-th/, texlive-module-ti/. A similar
> but simpler option is to use file names as range bounds (the same way
> dictionaries use words to demarcate page bounds): each directory will
> have a name of the first file located inside. This way files will be
> distributed evenly and it's still easy to pick a correct directory where
> a file will be located manually.
This was discussed early on, but thank you for the reminder, as it got
dropped from later discussions.

> [snip code]
> Using the approach above the files will distributed evenly among the
> directories keeping the possibility to determine the directory for a
> specific file by hand. It's possible if necessary to keep the directory
> structure unchanged for very long time and it will likely stay
> well-balanced. Picking a directory for a file is very cheap. The only
> obvious downside I see is that it's necessary to know list of
> directories to pick the correct one (can be mitigated by caching the
> list of directories if important). If it's desirable to make directory
> names shorter or to look less like file names it's fairly easy to
> achieve by keeping only unique prefixes of directories. For example:
As for the problem you describe, one of the requirements in the
discussion is that given ONLY the file or filename, and NOTHING ELSE, it
should be possible to determine where in a hierarchy it should go. No
prior knowledge about the hierarchy was permitted. Some parties might
answer that you just need an index file then, but that means you have to
keep the index file in sync often.

It's a superbly readable result (in the general class of perfect hashes
based on lots of well-known input). The class of solution suffers
another problem in addition the one you noted: if input changes
sufficiently, then rebalancing is expensive/hard.

As a concrete example, say we add a new category for something something
with lots of common prefixes in distfiles. 
dev-scratch/ as an example, where all distfiles start with 'scratch-'.
Unless we know up-front that we're going to add a thousand distfiles
here (not unreasonable, dev-python is ~1800 packages), they might start
by going into the 'sc' directory, but later we want them to be in
'scratch', as the tree is unweighted otherwise.

-- 
Robin Hugh Johnson
Gentoo Linux: Dev, Infra Lead, Foundation Treasurer
E-Mail   : robbat2@gentoo.org
GnuPG FP : 11ACBA4F 4778E3F6 E4EDF38E B27B944E 34884E85
GnuPG FP : 7D0B3CEB E9B85B1F 825BCECF EE05E6F6 A48F6136

[-- Attachment #2: Digital signature --]
[-- Type: application/pgp-signature, Size: 1113 bytes --]

Re: [gentoo-dev] [News item review] Portage rsync tree verification (v5)

[Michał Górny]

Please may it be the last!

---
Title: Portage rsync tree verification
Author: Michał Górny <mgorny@gentoo.org>
Posted: 2018-01-xx
Revision: 1
News-Item-Format: 2.0
Display-If-Installed: sys-apps/portage

Starting with sys-apps/portage-2.3.22, Portage will verify the Gentoo
repository after rsync by default.

The new verification is intended for users who are syncing via rsync.
Users syncing via git or other methods are not affected, and complete
verification for them will be provided in the future.

The verification is implemented via app-portage/gemato. Currently,
the whole repository is verified after syncing. On systems with slow
hard drives, this could take around 2 minutes. If you wish to disable
it, you can disable the 'rsync-verify' USE flag on sys-apps/portage
or set 'sync-rsync-verify-metamanifest = no' in your repos.conf.

Please note that the verification currently does not prevent Portage
from using the repository after syncing. If 'emerge --sync' fails,
do not install any packages and retry syncing. In case of prolonged
or frequent verification failures, please make sure to report a bug
including the failing mirror addresses (found in emerge.log).

The verification uses information from the binary keyring provided
by the app-crypt/gentoo-keys package. The keys are refreshed
from the keyserver before every use in order to check for revocation.
The post-sync verification ensures that the key package is verified
itself. However, manual verification is required before the first use.

On Gentoo installations created using installation media that included
portage-2.3.22, the keys will already be covered by the installation
media signatures. On existing installations, you need to manually
compare the primary key fingerprint (reported by gemato on every sync)
against the official Gentoo keys [1]. An example gemato output is:

  INFO:root:Valid OpenPGP signature found:
  INFO:root:- primary key: 1234567890ABCDEF1234567890ABCDEF12345678
  INFO:root:- subkey: FEDCBA0987654321FEDCBA0987654321FEDCBA09

Please note that the above snippet does not include the real key id
on purpose. The primary key actually printed by gemato must match
the 'Gentoo Portage Snapshot Signing Key' on the website. Please make
sure to also check the certificate used for the secure connection
to the site!

[1]:https://www.gentoo.org/downloads/signatures/

-- 
Best regards,
Michał Górny