home: services: ssh: Do not empty ~/.ssh/authorized_keys by default.

The default was an empty list which would remove any ~/.ssh/authorized_keys
file and replace it with a symlink to an empty file.  On some systems, notably
Ubuntu 22.10, the guix home generated ~/.ssh/authorized_keys file does not
allow login.

* doc/guix.texi (Secure Shell): Update, describe default #false value.
* gnu/home/services/ssh.scm (<home-openssh-configuration>)
[authorized-keys]: Change default to #f.
(openssh-configuration-files): Cater for default #f value: Do not register
"authorized_keys".

1 files changed, 5 insertions, 3 deletions

diff --git a/doc/guix.texi b/doc/guix.texi
index f4cca66d76..3cd9582558 100644
--- a/doc/guix.texi
+++ b/doc/guix.texi
@@ -42960,9 +42960,11 @@ stateless: it can be replicated elsewhere or at another point in time.
 Preparing this list can be relatively tedious though, which is why
 @code{*unspecified*} is kept as a default.
 
-@item @code{authorized-keys} (default: @code{'()})
-This must be a list of file-like objects, each of which containing an
-SSH public key that should be authorized to connect to this machine.
+@item @code{authorized-keys} (default: @code{#false})
+The default @code{#false} value means: Leave any
+@file{~/.ssh/authorized_keys} file alone.  Otherwise, this must be a
+list of file-like objects, each of which containing an SSH public key
+that should be authorized to connect to this machine.
 
 Concretely, these files are concatenated and made available as
 @file{~/.ssh/authorized_keys}.  If an OpenSSH server, @command{sshd}, is