From: Matthew Bullock <mbullock@thegoodpenguin.co.uk>
Date: Thu, 27 Jun 2024 13:15:56 +0000 (+0100)
Subject: openssh: allow configuration of hostkey type
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=0827c29566f3ea63715a9f9e4ee2639f4eabe0bd;p=thirdparty%2Fopenembedded%2Fopenembedded-core-contrib.git

openssh: allow configuration of hostkey type

Allow selection of host key types used by openssh via PACKAGECONFIG.
Any combination of hostkey-rsa, hostkey-ecdsa and hostkey-ed25519 can be
specified. Default to just generating ecdsa keys.

The current default generates all three keys. This can take a
significant amount of time on first boot. Having all three keys does not
significantly increase compatability. Also RSA keys are being deprecated
as they are no longer considered secure. Using just an ecdsa key reduces
key generation time by roughly 75%.

Signed-off-by: Matthew Bullock <mbullock@thegoodpenguin.co.uk>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
---

diff --git a/meta/recipes-connectivity/openssh/openssh_9.7p1.bb b/meta/recipes-connectivity/openssh/openssh_9.7p1.bb
index ab453f7bbeb..0bc14c55539 100644
--- a/meta/recipes-connectivity/openssh/openssh_9.7p1.bb
+++ b/meta/recipes-connectivity/openssh/openssh_9.7p1.bb
@@ -56,7 +56,7 @@ DEPENDS += "${@bb.utils.contains('DISTRO_FEATURES', 'systemd', 'systemd', '', d)
 
 # systemd-sshd-socket-mode means installing sshd.socket
 # and systemd-sshd-service-mode corresponding to sshd.service
-PACKAGECONFIG ??= "systemd-sshd-socket-mode"
+PACKAGECONFIG ??= "systemd-sshd-socket-mode hostkey-ecdsa"
 PACKAGECONFIG[fido2] = "--with-security-key-builtin,--disable-security-key,libfido2"
 PACKAGECONFIG[kerberos] = "--with-kerberos5,--without-kerberos5,krb5"
 PACKAGECONFIG[ldns] = "--with-ldns,--without-ldns,ldns"
@@ -64,6 +64,9 @@ PACKAGECONFIG[libedit] = "--with-libedit,--without-libedit,libedit"
 PACKAGECONFIG[manpages] = "--with-mantype=man,--with-mantype=cat"
 PACKAGECONFIG[systemd-sshd-socket-mode] = ""
 PACKAGECONFIG[systemd-sshd-service-mode] = ""
+PACKAGECONFIG[hostkey-rsa] = ""
+PACKAGECONFIG[hostkey-ecdsa] = ""
+PACKAGECONFIG[hostkey-ed25519] = ""
 
 EXTRA_AUTORECONF += "--exclude=aclocal"
 
@@ -127,13 +130,31 @@ do_install:append () {
 	install -m 644 ${UNPACKDIR}/volatiles.99_sshd ${D}/${sysconfdir}/default/volatiles/99_sshd
 	install -m 0755 ${S}/contrib/ssh-copy-id ${D}${bindir}
 
+        # 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
+        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
+        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
+        fi
+
 	# Create config files for read-only rootfs
 	install -d ${D}${sysconfdir}/ssh
 	install -m 644 ${D}${sysconfdir}/ssh/sshd_config ${D}${sysconfdir}/ssh/sshd_config_readonly
 	sed -i '/HostKey/d' ${D}${sysconfdir}/ssh/sshd_config_readonly
-	echo "HostKey /var/run/ssh/ssh_host_rsa_key" >> ${D}${sysconfdir}/ssh/sshd_config_readonly
-	echo "HostKey /var/run/ssh/ssh_host_ecdsa_key" >> ${D}${sysconfdir}/ssh/sshd_config_readonly
-	echo "HostKey /var/run/ssh/ssh_host_ed25519_key" >> ${D}${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
+        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
+        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
+        fi
 
 	install -d ${D}${systemd_system_unitdir}
 	if ${@bb.utils.contains('PACKAGECONFIG','systemd-sshd-socket-mode','true','false',d)}; then