| Message ID | 20240627131557.2047296-1-mbullock@thegoodpenguin.co.uk |
|---|---|
| State | Accepted, archived |
| Commit | 0827c29566f3ea63715a9f9e4ee2639f4eabe0bd |
| Headers | show |
| Series | openssh: allow configuration of hostkey type | expand |
On Thu, 27 Jun 2024 at 14:19, Matthew Bullock via lists.openembedded.org <mbullock=thegoodpenguin.co.uk@lists.openembedded.org> wrote: > > 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> > --- > .../openssh/openssh_9.7p1.bb | 29 ++++++++++++++++--- > 1 file changed, 25 insertions(+), 4 deletions(-) > > diff --git a/meta/recipes-connectivity/openssh/openssh_9.7p1.bb b/meta/recipes-connectivity/openssh/openssh_9.7p1.bb > index ab453f7bbe..0bc14c5553 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 ${@bb.utils.contains('PACKAGECONFIG','systemd-sshd-socket-mode','true','false',d)}; then > -- > 2.43.0 > Reviewed-by: Andrew Murray <amurray@thegoodpenguin.co.uk> Thanks, Andrew Murray
"Matthew Bullock via lists.openembedded.org" <mbullock=thegoodpenguin.co.uk@lists.openembedded.org> writes: > Allow selection of host key types used by openssh via PACKAGECONFIG. > Any combination of hostkey-rsa, hostkey-ecdsa and hostkey-ed25519 can be > specified. Default to just generating ecdsa keys. > > The current default generates all three keys. This can take a > significant amount of time on first boot. Having all three keys does not > significantly increase compatability. Also RSA keys are being deprecated > as they are no longer considered secure. Using just an ecdsa key reduces > key generation time by roughly 75%. > > Signed-off-by: Matthew Bullock <mbullock@thegoodpenguin.co.uk> > --- > .../openssh/openssh_9.7p1.bb | 29 ++++++++++++++++--- > 1 file changed, 25 insertions(+), 4 deletions(-) > > diff --git a/meta/recipes-connectivity/openssh/openssh_9.7p1.bb b/meta/recipes-connectivity/openssh/openssh_9.7p1.bb > index ab453f7bbe..0bc14c5553 100644 > --- a/meta/recipes-connectivity/openssh/openssh_9.7p1.bb > +++ b/meta/recipes-connectivity/openssh/openssh_9.7p1.bb > @@ -56,7 +56,7 @@ DEPENDS += "${@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 This will break our setup. We rely on the sshd_config including the Include /etc/ssh/sshd_config.d/*.conf directive and put a hostkeys.conf file in there, specifying the host key(s) types and paths we need (we have a readonly rootfs, but do have a place for persistent and per-machine stuff like this, so we use neither of the /etc or /var/run paths). I suppose we can remove hostkey-ecdsa and any other hostkey-* that may appear in PACKAGECONFIG in the future. But I think others may, for example, have a .bbappend where they supply a whole alternative sshd_config with similar explicit HostKey settings, and this would also break for them. So perhaps this could/should be guarded by 'grep -i ^hostkey' not finding anything in sshd_config or sshd_config.d/*.conf ? Rasmus
diff --git a/meta/recipes-connectivity/openssh/openssh_9.7p1.bb b/meta/recipes-connectivity/openssh/openssh_9.7p1.bb index ab453f7bbe..0bc14c5553 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
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> --- .../openssh/openssh_9.7p1.bb | 29 ++++++++++++++++--- 1 file changed, 25 insertions(+), 4 deletions(-)