From: Christopher Allan Webber <cwebber@dustycloud.org>
To: "Ludovic Courtès" <ludo@gnu.org>
Cc: 22883@debbugs.gnu.org
Subject: bug#22883: Authenticating a Git checkout
Date: Sun, 05 Jun 2016 15:39:04 -0500 [thread overview]
Message-ID: <87h9d7e5g7.fsf@dustycloud.org> (raw)
In-Reply-To: <87wpm519um.fsf@gnu.org>
Ludovic Courtès writes:
>>> Second, even if it did, it would be a shallow check: as Mike notes in
>>> <https://mikegerwitz.com/papers/git-horror-story> with the ‘signchk’
>>> script, you actually have to traverse the whole commit history and
>>> authenticate them one by one. But that’s OK, it runs in presumably less
>>> than a minute on a repo the size of Guix’s, and we could also stop at
>>> signed tags to avoid redundant checks.
>>
>> Practically speaking, that's probably fine, though note that a signed
>> tag is just a signed hash of the commit it points to (with some
>> metadata), so you're trusting the integrity of SHA-1 and nothing
>> more.
>>
>> With that said, the tag points to what will hopefully be a signed
>> commit, so if you verify the signature of the tag _and_ that commit,
>> that'd be even better. Git's use of SHA-1 makes cryptographic
>> assurances difficult/awkward.
>>
>> An occasional traversal of the entire DAG by, say, a CI script would
>> provide some pretty good confidence. I wouldn't say it's necessary for
>> every pull.
>
> Agreed.
One theoretical optimization: if I verify the DAG, could I store
somewhere that I've verified from commit cabba6e and upward already, so
the next time I verify it only has to verify the new commits?
Mostly makes sense if we're already going down the only mildly
crazypants direction of implementing our own tooling :)
- Chris
next prev parent reply other threads:[~2016-06-05 20:40 UTC|newest]
Thread overview: 78+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-03-02 18:03 bug#22883: Trustable "guix pull" Christopher Allan Webber
2016-03-02 19:26 ` Leo Famulari
2016-03-02 21:07 ` Christopher Allan Webber
2016-04-25 22:25 ` Ludovic Courtès
2016-04-26 0:13 ` Leo Famulari
2016-04-26 0:17 ` Thompson, David
2016-04-26 7:12 ` Ludovic Courtès
2016-04-30 4:43 ` Mike Gerwitz
2016-06-03 16:12 ` bug#22883: Authenticating a Git checkout Ludovic Courtès
2016-06-03 20:17 ` Leo Famulari
2016-06-04 11:04 ` Ludovic Courtès
2016-06-04 4:24 ` Mike Gerwitz
2016-06-04 11:17 ` Ludovic Courtès
2016-06-04 12:45 ` ng0
2016-06-06 12:20 ` ng0
2016-06-04 16:14 ` Mike Gerwitz
2016-06-05 20:39 ` Christopher Allan Webber [this message]
2016-06-05 21:15 ` Leo Famulari
2016-06-06 2:41 ` Mike Gerwitz
2016-06-06 7:01 ` Ludovic Courtès
2016-07-22 8:22 ` Ludovic Courtès
2016-07-22 12:58 ` Thompson, David
2016-07-22 13:58 ` Ludovic Courtès
2017-10-24 23:30 ` Ludovic Courtès
2019-12-27 19:48 ` Ricardo Wurmus
2019-12-28 14:47 ` Ludovic Courtès
2019-12-28 16:05 ` Ricardo Wurmus
2019-12-28 17:45 ` Ludovic Courtès
2020-04-30 15:32 ` Ludovic Courtès
2020-05-01 15:46 ` Justus Winter
2020-05-01 16:50 ` Ludovic Courtès
2020-05-01 17:04 ` Ludovic Courtès
2020-05-19 20:23 ` Ludovic Courtès
2020-06-01 14:07 ` bug#22883: Channel introductions Ludovic Courtès
2020-06-02 23:45 ` zimoun
2020-06-03 9:50 ` Ludovic Courtès
2020-06-03 16:20 ` zimoun
2020-06-04 9:55 ` Ludovic Courtès
2020-05-01 17:20 ` bug#22883: Authenticating a Git checkout Ludovic Courtès
2020-05-02 22:02 ` Ludovic Courtès
2020-05-04 8:03 ` Ludovic Courtès
2016-06-01 16:47 ` bug#22883: Discussion of TUF in the context of Git checkout authentication Ludovic Courtès
2016-05-15 12:40 ` bug#22883: Trustable "guix pull" fluxboks
2016-05-16 17:55 ` Thompson, David
2016-05-17 21:19 ` Ludovic Courtès
2016-06-04 16:19 ` Werner Koch
2016-06-04 22:27 ` Ludovic Courtès
2016-06-05 7:51 ` Werner Koch
2016-06-06 21:01 ` Leo Famulari
2016-06-07 8:08 ` bug#22883: gpg2 vs. gpg Ludovic Courtès
2016-06-07 11:25 ` Werner Koch
2016-06-07 12:58 ` ng0
2016-06-05 1:43 ` bug#22883: Trustable "guix pull" Mike Gerwitz
2018-08-28 19:56 ` Vagrant Cascadian
2018-09-02 16:05 ` Ludovic Courtès
2018-09-02 17:15 ` Vagrant Cascadian
2018-09-02 20:07 ` Ludovic Courtès
2019-12-20 22:11 ` bug#22883: Authenticating Git checkouts: step #1 Ludovic Courtès
[not found] ` <87mubmodfb.fsf_-_@gnu.org>
2019-12-21 1:33 ` zimoun
2019-12-27 12:58 ` Ludovic Courtès
[not found] ` <87eewqgc1v.fsf@gnu.org>
2019-12-27 20:47 ` Ricardo Wurmus
[not found] ` <87o8vto5rl.fsf@elephly.net>
2019-12-29 2:45 ` Vagrant Cascadian
[not found] ` <87a77bzw6p.fsf@yucca>
2019-12-29 7:34 ` Efraim Flashner
2019-12-30 21:29 ` Ludovic Courtès
2019-12-31 19:16 ` Jakub Kądziołka
2020-01-08 13:30 ` Ludovic Courtès
2020-06-02 13:49 ` bug#22883: Authenticating a Git checkout John Soo
2020-06-03 9:33 ` Ludovic Courtès
2020-06-08 21:54 ` bug#22883: [PATCH 1/9] git-authenticate: Cache takes a key parameter Ludovic Courtès
2020-06-08 21:54 ` bug#22883: [PATCH 2/9] git-authenticate: 'authenticate-commits' takes a #:keyring parameter Ludovic Courtès
2020-06-08 21:54 ` bug#22883: [PATCH 3/9] tests: Move OpenPGP helpers to (guix tests gnupg) Ludovic Courtès
2020-06-08 21:54 ` bug#22883: [PATCH 4/9] channels: 'latest-channel-instance' authenticates Git checkouts Ludovic Courtès
2020-06-08 21:54 ` bug#22883: [PATCH 5/9] channels: Make 'validate-pull' call right after clone/pull Ludovic Courtès
2020-06-08 21:54 ` bug#22883: [PATCH 6/9] .guix-channel: Add 'keyring-reference' Ludovic Courtès
2020-06-08 21:54 ` bug#22883: [PATCH 7/9] channels: Automatically add introduction for the official 'guix' channel Ludovic Courtès
2020-06-08 21:54 ` bug#22883: [PATCH 8/9] pull: Add '--disable-authentication' Ludovic Courtès
2020-06-08 21:54 ` bug#22883: [PATCH 9/9] DROP? channels: Add prehistorical authorizations to <channel-introduction> Ludovic Courtès
2020-06-08 22:04 ` bug#22883: [PATCH 1/9] git-authenticate: Cache takes a key parameter Ludovic Courtès
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
List information: https://guix.gnu.org/
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=87h9d7e5g7.fsf@dustycloud.org \
--to=cwebber@dustycloud.org \
--cc=22883@debbugs.gnu.org \
--cc=ludo@gnu.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
Code repositories for project(s) associated with this public inbox
https://git.savannah.gnu.org/cgit/guix.git
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).