diff mbox series

[kirkstone,11/16] rootfs-postcommands.bbclass: avoid moving ssh host keys if etc is writable

Message ID 31cff4d182faed31747d00cc82c1cf0a05a81431.1663078051.git.steve@sakoman.com
State Accepted, archived
Commit 31cff4d182faed31747d00cc82c1cf0a05a81431
Headers show
Series [kirkstone,01/16] cracklib: upgrade 2.9.7 -> 2.9.8 | expand

Commit Message

Steve Sakoman Sept. 13, 2022, 2:17 p.m. UTC 
From: Peter Bergin <peter@berginkonsult.se>

When using IMAGE_FEATURE read-only-rootfs ssh host keys are moved to volatile
storage. If the feature overlayfs-etc is used in addition to read-only-rootfs
/etc is writable and the move is not wanted. But in the case also the IMAGE_FEATURE
stateless-rootfs is used the keys will be moved as storage of keys should not
be wanted in a stateless-rootfs.

This change only takes effect in the case IMAGE_FEATURE contains read-only-rootfs.
In adddition the following cases are handled:

  IMAGE_FEATURES = "read-only-rootfs" --> ssh keys/config handled as ro root
  IMAGE_FEATURES = "read-only-rootfs overlayfs-etc" --> ssh keys/config handled as rw root
  IMAGE_FEATURES = "read-only-rootfs stateless-rootfs" --> ssh keys/config handled as ro root
  IMAGE_FEATURES = "read-only-rootfs overlayfs-etc stateless-rootfs" --> ssh keys/config handled as ro root

Signed-off-by: Peter Bergin <peter@berginkonsult.se>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
(cherry picked from commit d2ad7aa1f2153955adc044ea4eb11c48086a01d1)
Signed-off-by: Steve Sakoman <steve@sakoman.com>
---
 meta/classes/rootfs-postcommands.bbclass | 30 ++++++++++++++----------
 1 file changed, 17 insertions(+), 13 deletions(-)
diff mbox series

Patch

diff --git a/meta/classes/rootfs-postcommands.bbclass b/meta/classes/rootfs-postcommands.bbclass
index a59d9b5878..5c0b3ec37c 100644
--- a/meta/classes/rootfs-postcommands.bbclass
+++ b/meta/classes/rootfs-postcommands.bbclass
@@ -14,7 +14,7 @@  ROOTFS_POSTPROCESS_COMMAND += '${@bb.utils.contains_any("IMAGE_FEATURES", [ 'deb
 # Create /etc/timestamp during image construction to give a reasonably sane default time setting
 ROOTFS_POSTPROCESS_COMMAND += "rootfs_update_timestamp; "
 
-# Tweak the mount options for rootfs in /etc/fstab if read-only-rootfs is enabled
+# Tweak files in /etc if read-only-rootfs is enabled
 ROOTFS_POSTPROCESS_COMMAND += '${@bb.utils.contains("IMAGE_FEATURES", "read-only-rootfs", "read_only_rootfs_hook; ", "",d)}'
 
 # We also need to do the same for the kernel boot parameters,
@@ -103,20 +103,24 @@  read_only_rootfs_hook () {
 	# If we're using openssh and the /etc/ssh directory has no pre-generated keys,
 	# we should configure openssh to use the configuration file /etc/ssh/sshd_config_readonly
 	# and the keys under /var/run/ssh.
-	if [ -d ${IMAGE_ROOTFS}/etc/ssh ]; then
-		if [ -e ${IMAGE_ROOTFS}/etc/ssh/ssh_host_rsa_key ]; then
-			echo "SYSCONFDIR=\${SYSCONFDIR:-/etc/ssh}" >> ${IMAGE_ROOTFS}/etc/default/ssh
-			echo "SSHD_OPTS=" >> ${IMAGE_ROOTFS}/etc/default/ssh
-		else
-			echo "SYSCONFDIR=\${SYSCONFDIR:-/var/run/ssh}" >> ${IMAGE_ROOTFS}/etc/default/ssh
-			echo "SSHD_OPTS='-f /etc/ssh/sshd_config_readonly'" >> ${IMAGE_ROOTFS}/etc/default/ssh
+	# If overlayfs-etc is used this is not done as /etc is treated as writable
+	# If stateless-rootfs is enabled this is always done as we don't want to save keys then
+	if ${@ 'true' if not bb.utils.contains('IMAGE_FEATURES', 'overlayfs-etc', True, False, d) or bb.utils.contains('IMAGE_FEATURES', 'stateless-rootfs', True, False, d) else 'false'}; then
+		if [ -d ${IMAGE_ROOTFS}/etc/ssh ]; then
+			if [ -e ${IMAGE_ROOTFS}/etc/ssh/ssh_host_rsa_key ]; then
+				echo "SYSCONFDIR=\${SYSCONFDIR:-/etc/ssh}" >> ${IMAGE_ROOTFS}/etc/default/ssh
+				echo "SSHD_OPTS=" >> ${IMAGE_ROOTFS}/etc/default/ssh
+			else
+				echo "SYSCONFDIR=\${SYSCONFDIR:-/var/run/ssh}" >> ${IMAGE_ROOTFS}/etc/default/ssh
+				echo "SSHD_OPTS='-f /etc/ssh/sshd_config_readonly'" >> ${IMAGE_ROOTFS}/etc/default/ssh
+			fi
 		fi
-	fi
 
-	# Also tweak the key location for dropbear in the same way.
-	if [ -d ${IMAGE_ROOTFS}/etc/dropbear ]; then
-		if [ ! -e ${IMAGE_ROOTFS}/etc/dropbear/dropbear_rsa_host_key ]; then
-			echo "DROPBEAR_RSAKEY_DIR=/var/lib/dropbear" >> ${IMAGE_ROOTFS}/etc/default/dropbear
+		# Also tweak the key location for dropbear in the same way.
+		if [ -d ${IMAGE_ROOTFS}/etc/dropbear ]; then
+			if [ ! -e ${IMAGE_ROOTFS}/etc/dropbear/dropbear_rsa_host_key ]; then
+				echo "DROPBEAR_RSAKEY_DIR=/var/lib/dropbear" >> ${IMAGE_ROOTFS}/etc/default/dropbear
+			fi
 		fi
 	fi