Add default id_ed25519.pub and signing-key.pub

This makes it easier to deploy the VM to the Libre En Communs
infrastructure as it doesn't require to also copy these files to the
VM producing the image.

Signed-off-by: Denis 'GNUtoo' Carikli <GNUtoo@cyberdimension.org>

Makefile.am

@@ -34,7 +34,7 @@ guix-commit.txt: Makefile
 %.html: %.html.tmpl guix-commit.txt Makefile
 	sed 's#DOMAIN#$(DOMAIN)#g' $< > $@
 
-%.scm: %.scm.tmpl guix-commit.txt Makefile
+%.scm: %.scm.tmpl guix-commit.txt id_ed25519.pub Makefile signing-key.pub
 	sed \
 		"s#DOMAIN#$(DOMAIN)#g ; \
 		s#ENABLE_WIREGUARD#$(ENABLE_WIREGUARD)#g ; \
@@ -55,6 +55,19 @@ guix-commit.txt: Makefile
 		s#VM_SSH_ADDRESS#$(VM_SSH_ADDRESS)#g" $< > $@
 	chmod +x $@
 
+# Generate default key. Can be changed by replacing id_ed25519.pub.
+id_ed25519.pub:
+	printf "ssh-ed25519 %s %s" \
+	'AAAAC3NzaC1lZDI1NTE5AAAAIH2feuEj4asx0ImCG+cuiPv2WdKF6vMI+cJtZyG9cwUQ' \
+	'gnutoo@primary_laptop'
+	> $@
+
+# Generate default key. Can be changed by replacing signing-key.pub.
+signing-key.pub:
+	printf '(public-key (ecc (curve Ed25519) (q #%s#)))\n' \
+	'3A7E1F41E2D5784CFCABB39CB73F99E727D4A5C1ECA79D873587D63D093CC4B5' \
+	>$@
+
 IMAGE_SOURCE = \
 	first-boot.sh \
 	guix-commit.txt \