nuageinit: support allow_public_ssh_keys

Skip importing datasource public keys when set to false.

libexec/nuageinit/nuageinit

@@ -18,7 +18,8 @@ local citype = arg[2]
 
 local function default_user(obj, metadata)
 	local ssh_authorized_keys = {}
-	if type(metadata.public_keys) == "table" then
+	if (not obj or obj.allow_public_ssh_keys ~= false) and
+	    type(metadata.public_keys) == "table" then
 		for _, k in pairs(metadata.public_keys) do
 			table.insert(ssh_authorized_keys, k)
 		end
@@ -604,7 +605,8 @@ local function disable_root(obj, metadata)
 		opts = opts:gsub("%$DISABLE_USER", "root")
 	end
 	local keys = {}
-	if type(metadata.public_keys) == "table" then
+	if obj.allow_public_ssh_keys ~= false and
+	    type(metadata.public_keys) == "table" then
 		for _, k in pairs(metadata.public_keys) do
 			table.insert(keys, k)
 		end

libexec/nuageinit/nuageinit.7

@@ -323,6 +323,16 @@ being the actual content of the files in
 Append each entry of the array to
 .Nm
 default user which will be created.
+.It Ic allow_public_ssh_keys
+Boolean which determines if the public SSH keys from the datasource
+metadata are imported to the default user and root.
+If set to
+.Ar false ,
+only the keys specified in
+.Ic ssh_authorized_keys
+are used.
+Defaults to
+.Ar true .
 .It Ic ssh_pwauth
 boolean which determines the value of the
 .Qq Ic PasswordAuthentication

libexec/nuageinit/tests/nuageinit.sh

@@ -385,6 +385,46 @@ EOF
 	atf_check -o inline:"ssh-ed25519 my_key_id tdb@host\n" cat home/freebsd/.ssh/authorized_keys
 }
 
+config2_pubkeys_allow_public_ssh_keys_head()
+{
+	atf_set "require.user" root
+}
+config2_pubkeys_allow_public_ssh_keys_body()
+{
+	here=$(pwd)
+	export NUAGE_FAKE_ROOTDIR=$(pwd)
+	if [ $(id -u) -ne 0 ]; then
+		atf_skip "root required"
+	fi
+	mkdir -p media/nuageinit
+	cat > media/nuageinit/meta_data.json << EOF
+{
+    "uuid": "uuid_for_this_instance",
+    "public_keys": {
+        "tdb": "ssh-ed25519 my_key_id tdb@host"
+    }
+}
+EOF
+	cat > media/nuageinit/user_data << EOF
+#cloud-config
+allow_public_ssh_keys: false
+EOF
+	mkdir -p etc
+	mkdir -p root
+	cat > etc/master.passwd << EOF
+root:*:0:0::0:0:Charlie &:/root:/bin/csh
+sys:*:1:0::0:0:Sys:/home/sys:/bin/csh
+EOF
+	pwd_mkdb -d etc ${here}/etc/master.passwd
+	cat > etc/group << EOF
+wheel:*:0:root
+users:*:1:
+EOF
+	atf_check /usr/libexec/nuageinit ${here}/media/nuageinit config-2
+	# no public key should be imported
+	atf_check -s exit:1 test -e home/freebsd/.ssh/authorized_keys
+}
+
 config2_network_body()
 {
 	mkdir -p media/nuageinit
@@ -1509,6 +1549,7 @@ atf_init_test_cases()
 	atf_add_test_case config2_pubkeys
 	atf_add_test_case config2_pubkeys_user_data
 	atf_add_test_case config2_pubkeys_meta_data
+	atf_add_test_case config2_pubkeys_allow_public_ssh_keys
 	atf_add_test_case config2_network
 	atf_add_test_case config2_network_static_v4
 	atf_add_test_case config2_network_dns