openssh: add variable for key path

This patch adds a variable for the key directory path. This is especially
useful when working with a read-only file system where you want to
specify the location e.g. on a r/w partition. To be consistent, the
change was also done for the read write path.

For changing the path simply create a bbappend and override the
variable.

Signed-off-by: Patrick Vogelaar <patrick.vogelaar.dev@mailbox.org>
---
 .../openssh/openssh_10.2p1.bb                    | 16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

On Fri, 2026-01-02 at 12:27 +0100, Patrick Vogelaar via
lists.openembedded.org wrote:
> This patch adds a variable for the key directory path. This is especially
> useful when working with a read-only file system where you want to
> specify the location e.g. on a r/w partition. To be consistent, the
> change was also done for the read write path.
> 
> For changing the path simply create a bbappend and override the
> variable.
> 
> Signed-off-by: Patrick Vogelaar <patrick.vogelaar.dev@mailbox.org>
> ---
>  .../openssh/openssh_10.2p1.bb                    | 16 ++++++++++------
>  1 file changed, 10 insertions(+), 6 deletions(-)
> 
> diff --git a/meta/recipes-connectivity/openssh/openssh_10.2p1.bb b/meta/recipes-connectivity/openssh/openssh_10.2p1.bb
> index 866129573f..e319f4ac24 100644
> --- a/meta/recipes-connectivity/openssh/openssh_10.2p1.bb
> +++ b/meta/recipes-connectivity/openssh/openssh_10.2p1.bb
> @@ -99,6 +99,10 @@ CACHED_CONFIGUREVARS += "ac_cv_path_PATH_PASSWD_PROG=${bindir}/passwd"
>  # We don't want to depend on libblockfile
>  CACHED_CONFIGUREVARS += "ac_cv_header_maillock_h=no"
>  
> +# This allows overriding the key location in a bbappend
> +RO_SSH_KEY_DIR ?= "/var/run/ssh"
> +SSH_KEY_DIR ?= "/etc/ssh"

The naming here is very easy to confuse, but I guess it's to match with
the 'sshd_config' and 'sshd_config_readonly' filenames. I think we
should be explicit in the RO case that we're talking about the read-only
configuration though. And we'd prefer this as a suffix instead of a
prefix.

Oh, and we should make it clear that this is specific to openssh, then
these variables could be set from a config file instead of just a
bbappend. And make it clear that it's for the host keys while we're at
it.

Many 'and's there!

So, I suggest we use:

  OPENSSH_HOST_KEY_DIR
  OPENSSH_HOST_KEY_DIR_READONLY_CONFIG

> +
>  do_configure:prepend () {
>  	export LD="${CC}"
>  	install -m 0600 ${UNPACKDIR}/sshd_config ${B}/
> @@ -113,24 +117,24 @@ sshd_hostkey_setup() {
>  	# Enable specific ssh host keys
>  	sed -i '/HostKey/d' ${D}${sysconfdir}/ssh/sshd_config
>  	if ${@bb.utils.contains('PACKAGECONFIG','hostkey-rsa','true','false',d)}; then
> -		echo "HostKey /etc/ssh/ssh_host_rsa_key" >> ${D}${sysconfdir}/ssh/sshd_config
> +		echo "HostKey ${SSH_KEY_DIR}/ssh_host_rsa_key" >> ${D}${sysconfdir}/ssh/sshd_config
>  	fi
>  	if ${@bb.utils.contains('PACKAGECONFIG','hostkey-ecdsa','true','false',d)}; then
> -		echo "HostKey /etc/ssh/ssh_host_ecdsa_key" >> ${D}${sysconfdir}/ssh/sshd_config
> +		echo "HostKey ${SSH_KEY_DIR}/ssh_host_ecdsa_key" >> ${D}${sysconfdir}/ssh/sshd_config
>  	fi
>  	if ${@bb.utils.contains('PACKAGECONFIG','hostkey-ed25519','true','false',d)}; then
> -		echo "HostKey /etc/ssh/ssh_host_ed25519_key" >> ${D}${sysconfdir}/ssh/sshd_config
> +		echo "HostKey ${SSH_KEY_DIR}/ssh_host_ed25519_key" >> ${D}${sysconfdir}/ssh/sshd_config
>  	fi
>  
>  	sed -i '/HostKey/d' ${D}${sysconfdir}/ssh/sshd_config_readonly
>  	if ${@bb.utils.contains('PACKAGECONFIG','hostkey-rsa','true','false',d)}; then
> -		echo "HostKey /var/run/ssh/ssh_host_rsa_key" >> ${D}${sysconfdir}/ssh/sshd_config_readonly
> +		echo "HostKey ${RO_SSH_KEY_DIR}/ssh_host_rsa_key" >> ${D}${sysconfdir}/ssh/sshd_config_readonly
>  	fi
>  	if ${@bb.utils.contains('PACKAGECONFIG','hostkey-ecdsa','true','false',d)}; then
> -		echo "HostKey /var/run/ssh/ssh_host_ecdsa_key" >> ${D}${sysconfdir}/ssh/sshd_config_readonly
> +		echo "HostKey ${RO_SSH_KEY_DIR}/ssh_host_ecdsa_key" >> ${D}${sysconfdir}/ssh/sshd_config_readonly
>  	fi
>  	if ${@bb.utils.contains('PACKAGECONFIG','hostkey-ed25519','true','false',d)}; then
> -		echo "HostKey /var/run/ssh/ssh_host_ed25519_key" >> ${D}${sysconfdir}/ssh/sshd_config_readonly
> +		echo "HostKey ${RO_SSH_KEY_DIR}/ssh_host_ed25519_key" >> ${D}${sysconfdir}/ssh/sshd_config_readonly
>  	fi
>  }

Best regards,