[bug#70818] [PATCH] maint: Suggest ‘guix git authenticate’ for initial authentication.

[bug#70818] [PATCH] maint: Suggest ‘guix git authenticate’ for initial authentication.

[Ludovic Courtès]

The previous recommendation, running ‘make authenticate’, was insecure
because it led users to run code from the very repository they want to
authenticate:

  https://lists.gnu.org/archive/html/guix-devel/2024-04/msg00252.html

* Makefile.am (commit_v1_0_0, channel_intro_commit)
(channel_intro_signer, GUIX_GIT_KEYRING, authenticate): Remove.
* Makefile.am (.git/hooks/%): New target, generalization of previous
‘.git/hooks/pre-push’ target.
(nodist_noinst_DATA): Add ‘.git/hooks/post-merge’.
* doc/contributing.texi (Building from Git): Suggest ‘guix git
authenticate’ instead of ‘make authenticate’.
* etc/git/post-merge: New file.
* etc/git/pre-push: Run ‘guix git authenticate’ instead of ‘make
authenticate’.

Reported-by: Skyler Ferris <skyvine@protonmail.com>
Change-Id: Ia415aa8375013d0dd095e891116f6ce841d93efd
---
 Makefile.am           | 30 +++++++++---------------------
 doc/contributing.texi | 29 ++++++++++++++++++++++-------
 etc/git/post-merge    |  3 +++
 etc/git/pre-push      |  4 +++-
 4 files changed, 37 insertions(+), 29 deletions(-)
 create mode 100755 etc/git/post-merge

Hello there!

This addresses the security issue Skyler reported regarding
‘make authenticate’, basically removing the makefile target
and adjusting documentation accordingly.  It also adds a
‘post-merge’ hook like ‘guix git authenticate’ now does.

This assumes users have a (very) recent ‘guix git authenticate’
command, but I think that’s acceptable because this targets
an audience of developers.

Thoughts?

Ludo’.


diff --git a/Makefile.am b/Makefile.am
index 77c05ff63b7..d1d953b8923 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -1,5 +1,5 @@
 # GNU Guix --- Functional package management for GNU
-# Copyright © 2012-2023 Ludovic Courtès <ludo@gnu.org>
+# Copyright © 2012-2024 Ludovic Courtès <ludo@gnu.org>
 # Copyright © 2013 Andreas Enge <andreas@enge.fr>
 # Copyright © 2015, 2017 Alex Kost <alezost@gmail.com>
 # Copyright © 2016, 2018 Mathieu Lirzin <mthl@gnu.org>
@@ -895,22 +895,6 @@ $(guix_install_go_files): install-nobase_dist_guilemoduleDATA
 install-data-hook:
 	touch "$(DESTDIR)$(guileobjectdir)/guix/config.go"
 
-# Commit corresponding to the 'v1.0.0' tag.
-commit_v1_0_0 = 6298c3ffd9654d3231a6f25390b056483e8f407c
-
-# Introduction of the 'guix' channel.  Keep in sync with (guix channels)!
-channel_intro_commit = 9edb3f66fd807b096b48283debdcddccfea34bad
-channel_intro_signer = BBB0 2DDF 2CEA F6A8 0D1D  E643 A2A0 6DF2 A33A 54FA
-
-# Authenticate the current Git checkout by checking signatures on every commit.
-GUIX_GIT_KEYRING = origin/keyring
-authenticate:
-	$(AM_V_at)echo "Authenticating Git checkout..." ;	\
-	guix git authenticate					\
-	    --keyring=$(GUIX_GIT_KEYRING)			\
-	    --cache-key=channels/guix --stats			\
-	    "$(channel_intro_commit)" "$(channel_intro_signer)"
-
 # Assuming Guix is already installed and the daemon is up and running, this
 # rule builds from $(srcdir), creating and building derivations.
 as-derivation:
@@ -1227,13 +1211,13 @@ cuirass-jobs: $(GOBJECTS)
 .PHONY: gen-ChangeLog gen-AUTHORS gen-tarball-version
 .PHONY: assert-no-store-file-names assert-binaries-available
 .PHONY: assert-final-inputs-self-contained check-channel-news
-.PHONY: clean-go make-go as-derivation authenticate
+.PHONY: clean-go make-go as-derivation
 .PHONY: update-guix-package update-NEWS cuirass-jobs release
 
 # Git auto-configuration.
-.git/hooks/pre-push: etc/git/pre-push
+.git/hooks/%: etc/git/%
 	$(AM_V_at)if test -d .git; then \
-	cp etc/git/pre-push .git/hooks/pre-push; \
+	cp "$<" "$@"; \
 	fi
 
 .git/config: etc/git/gitconfig
@@ -1256,7 +1240,11 @@ COMMIT_MSG_MAGIC = VGhpcyBpcyB0aGUgY29tbWl0LW1zZyBob29rIG9mIEd1aXg=
 # from a tarball.  Do not add dependencies on these to *_DATA when building
 # from a tarball, as that breaks the build.
 if in_git_p
-nodist_noinst_DATA = .git/hooks/pre-push .git/config .git/hooks/commit-msg
+nodist_noinst_DATA =				\
+  .git/hooks/pre-push				\
+  .git/hooks/post-merge				\
+  .git/config					\
+  .git/hooks/commit-msg
 endif
 
 # Downloading up-to-date PO files.
diff --git a/doc/contributing.texi b/doc/contributing.texi
index 66f4e86d0a9..0005c846dc1 100644
--- a/doc/contributing.texi
+++ b/doc/contributing.texi
@@ -276,25 +276,40 @@ Building from Git
 checkout by running:
 
 @example
-make authenticate
+guix git authenticate \
+  9edb3f66fd807b096b48283debdcddccfea34bad \
+  "BBB0 2DDF 2CEA F6A8 0D1D  E643 A2A0 6DF2 A33A 54FA"
 @end example
 
 The first run takes a couple of minutes, but subsequent runs are faster.
+On subsequent runs, you can run the command without any arguments since
+the @dfn{introduction} (the commit ID and OpenPGP fingerprints above)
+will have been recorded@footnote{This requires a recent version of Guix,
+from May 2024 or more recent.}:
 
-Or, when your configuration for your local Git repository doesn't match
+@example
+guix git authenticate
+@end example
+
+When your configuration for your local Git repository doesn't match
 the default one, you can provide the reference for the @code{keyring}
-branch through the variable @code{GUIX_GIT_KEYRING}.  The following
+branch @i{via} the @option{-k} option.  The following
 example assumes that you have a Git remote called @samp{myremote}
 pointing to the official repository:
 
 @example
-make authenticate GUIX_GIT_KEYRING=myremote/keyring
+guix git authenticate \
+  -k myremote/keyring \
+  9edb3f66fd807b096b48283debdcddccfea34bad \
+  "BBB0 2DDF 2CEA F6A8 0D1D  E643 A2A0 6DF2 A33A 54FA"
 @end example
 
+@xref{Invoking guix git authenticate}, for more information on this
+command.
+
 @quotation Note
-You are advised to run @command{make authenticate} after every
-@command{git pull} invocation.  This ensures you keep receiving valid
-changes to the repository.
+By default, hooks installed such that @command{guix git authenticate} is
+invoked anytime you run @command{git pull} or @command{git push}.
 @end quotation
 
 After updating the repository, @command{make} might fail with an error
diff --git a/etc/git/post-merge b/etc/git/post-merge
new file mode 100755
index 00000000000..f2ad37d35c4
--- /dev/null
+++ b/etc/git/post-merge
@@ -0,0 +1,3 @@
+#!/bin/sh
+# Authenticate the repo upon 'git pull' and similar.
+exec guix git authenticate
diff --git a/etc/git/pre-push b/etc/git/pre-push
index 59671b0d583..325b23854bb 100755
--- a/etc/git/pre-push
+++ b/etc/git/pre-push
@@ -32,7 +32,9 @@ do
 		# Only use the hook when pushing to Savannah.
 		case "$2" in
 		    *.gnu.org*)
-			exec make authenticate check-channel-news
+			set -e
+			make check-channel-news
+			exec guix git authenticate
 			exit 127
 			;;
 		    *)

base-commit: 014875b29e68da6357a5323e6dd1eaa74a05b753
-- 
2.41.0

[bug#70818] [PATCH] maint: Suggest ‘guix git authenticate’ for initial authentication.

[pelzflorian (Florian Pelz)]

Thank you Ludo for this careful implementation.  I find One typo:

Ludovic Courtès <ludo@gnu.org> writes:
> diff --git a/doc/contributing.texi b/doc/contributing.texi
> index 66f4e86d0a9..0005c846dc1 100644
> --- a/doc/contributing.texi
> +++ b/doc/contributing.texi
> @@ -276,25 +276,40 @@ Building from Git
> […]
>  @quotation Note
> -You are advised to run @command{make authenticate} after every
> -@command{git pull} invocation.  This ensures you keep receiving valid
> -changes to the repository.
> +By default, hooks installed such that @command{guix git authenticate} is
> +invoked anytime you run @command{git pull} or @command{git push}.
>  @end quotation
>  
>  After updating the repository, @command{make} might fail with an error

By default, hooks *are*

Regards,
Florian

[bug#70818] [PATCH] maint: Suggest ‘guix git authenticate’ for initial authentication.

[Maxim Cournoyer]

Hi!

Ludovic Courtès <ludo@gnu.org> writes:

> The previous recommendation, running ‘make authenticate’, was insecure
> because it led users to run code from the very repository they want to
> authenticate:
>
>   https://lists.gnu.org/archive/html/guix-devel/2024-04/msg00252.html
>
> * Makefile.am (commit_v1_0_0, channel_intro_commit)
> (channel_intro_signer, GUIX_GIT_KEYRING, authenticate): Remove.
> * Makefile.am (.git/hooks/%): New target, generalization of previous
> ‘.git/hooks/pre-push’ target.
> (nodist_noinst_DATA): Add ‘.git/hooks/post-merge’.
> * doc/contributing.texi (Building from Git): Suggest ‘guix git
> authenticate’ instead of ‘make authenticate’.
> * etc/git/post-merge: New file.
> * etc/git/pre-push: Run ‘guix git authenticate’ instead of ‘make
> authenticate’.
>
> Reported-by: Skyler Ferris <skyvine@protonmail.com>
> Change-Id: Ia415aa8375013d0dd095e891116f6ce841d93efd

Reviewed-by: Maxim Cournoyer <maxim.cournoyer@gmail>

(taking into account the typo spotted by Florian).

Thank you for addressing this!

-- 
Thanks,
Maxim

bug#70818: [PATCH] maint: Suggest ‘guix git authenticate’ for initial authentication.

[Ludovic Courtès]

Hi,

Maxim Cournoyer <maxim.cournoyer@gmail.com> skribis:

> Ludovic Courtès <ludo@gnu.org> writes:
>
>> The previous recommendation, running ‘make authenticate’, was insecure
>> because it led users to run code from the very repository they want to
>> authenticate:
>>
>>   https://lists.gnu.org/archive/html/guix-devel/2024-04/msg00252.html
>>
>> * Makefile.am (commit_v1_0_0, channel_intro_commit)
>> (channel_intro_signer, GUIX_GIT_KEYRING, authenticate): Remove.
>> * Makefile.am (.git/hooks/%): New target, generalization of previous
>> ‘.git/hooks/pre-push’ target.
>> (nodist_noinst_DATA): Add ‘.git/hooks/post-merge’.
>> * doc/contributing.texi (Building from Git): Suggest ‘guix git
>> authenticate’ instead of ‘make authenticate’.
>> * etc/git/post-merge: New file.
>> * etc/git/pre-push: Run ‘guix git authenticate’ instead of ‘make
>> authenticate’.
>>
>> Reported-by: Skyler Ferris <skyvine@protonmail.com>
>> Change-Id: Ia415aa8375013d0dd095e891116f6ce841d93efd
>
> Reviewed-by: Maxim Cournoyer <maxim.cournoyer@gmail>
>
> (taking into account the typo spotted by Florian).

I fixed the typo and applied it, thanks!

Ludo’.