-# $OpenBSD: hostkey-rotate.sh,v 1.5 2015/09/04 04:23:10 djm Exp $
+# $OpenBSD: hostkey-rotate.sh,v 1.6 2019/08/30 05:08:28 dtucker Exp $
# Placed in the Public Domain.
tid="hostkey rotate"
# Need full names here since they are used in HostKeyAlgorithms
-HOSTKEY_TYPES="ecdsa-sha2-nistp256 ssh-ed25519 ssh-rsa ssh-dss"
+HOSTKEY_TYPES="`${SSH} -Q key-plain`"
rm -f $OBJ/hkr.* $OBJ/ssh_proxy.orig
echo "UpdateHostkeys=yes" >> $OBJ/ssh_proxy
rm $OBJ/known_hosts
+# The "primary" key type is ed25519 since it's supported even when built
+# without OpenSSL. The secondary is RSA if it's supported.
+primary="ssh-ed25519"
+secondary="$primary"
+
trace "prepare hostkeys"
nkeys=0
all_algs=""
-for k in `${SSH} -Q key-plain` ; do
+for k in $HOSTKEY_TYPES; do
${SSHKEYGEN} -qt $k -f $OBJ/hkr.$k -N '' || fatal "ssh-keygen $k"
echo "Hostkey $OBJ/hkr.${k}" >> $OBJ/sshd_proxy.orig
nkeys=`expr $nkeys + 1`
test "x$all_algs" = "x" || all_algs="${all_algs},"
all_algs="${all_algs}$k"
+ case "$k" in
+ ssh-rsa) secondary="ssh-rsa" ;;
+ esac
done
dossh() {
# Connect to sshd with StrictHostkeyChecking=no
verbose "learn hostkey with StrictHostKeyChecking=no"
>$OBJ/known_hosts
-dossh -oHostKeyAlgorithms=ssh-ed25519 -oStrictHostKeyChecking=no
+dossh -oHostKeyAlgorithms=$primary -oStrictHostKeyChecking=no
# Verify no additional keys learned
expect_nkeys 1 "unstrict connect keys"
-check_key_present ssh-ed25519 || fail "unstrict didn't learn key"
+check_key_present $primary || fail "unstrict didn't learn key"
# Connect to sshd as usual
verbose "learn additional hostkeys"
dossh -oStrictHostKeyChecking=yes -oHostKeyAlgorithms=$all_algs
# Check that other keys learned
expect_nkeys $nkeys "learn hostkeys"
-check_key_present ssh-rsa || fail "didn't learn keys"
+for k in $HOSTKEY_TYPES; do
+ check_key_present $k || fail "didn't learn keytype $k"
+done
# Check each key type
-for k in `${SSH} -Q key-plain` ; do
+for k in $HOSTKEY_TYPES; do
verbose "learn additional hostkeys, type=$k"
dossh -oStrictHostKeyChecking=yes -oHostKeyAlgorithms=$k,$all_algs
expect_nkeys $nkeys "learn hostkeys $k"
- check_key_present $k || fail "didn't learn $k"
+ check_key_present $k || fail "didn't learn $k correctly"
done
# Change one hostkey (non primary) and relearn
-verbose "learn changed non-primary hostkey"
-mv $OBJ/hkr.ssh-rsa.pub $OBJ/hkr.ssh-rsa.pub.old
-rm -f $OBJ/hkr.ssh-rsa
-${SSHKEYGEN} -qt ssh-rsa -f $OBJ/hkr.ssh-rsa -N '' || fatal "ssh-keygen $k"
-dossh -oStrictHostKeyChecking=yes -oHostKeyAlgorithms=$all_algs
-# Check that the key was replaced
-expect_nkeys $nkeys "learn hostkeys"
-check_key_present ssh-rsa $OBJ/hkr.ssh-rsa.pub.old && fail "old key present"
-check_key_present ssh-rsa || fail "didn't learn changed key"
+if [ "$primary" != "$secondary" ]; then
+ verbose "learn changed non-primary hostkey type=${secondary}"
+ mv $OBJ/hkr.${secondary}.pub $OBJ/hkr.${secondary}.pub.old
+ rm -f $OBJ/hkr.${secondary}
+ ${SSHKEYGEN} -qt ${secondary} -f $OBJ/hkr.${secondary} -N '' || \
+ fatal "ssh-keygen $secondary"
+ dossh -oStrictHostKeyChecking=yes -oHostKeyAlgorithms=$all_algs
+ # Check that the key was replaced
+ expect_nkeys $nkeys "learn hostkeys"
+ check_key_present ${secondary} $OBJ/hkr.${secondary}.pub.old && \
+ fail "old key present"
+ check_key_present ${secondary} || fail "didn't learn changed key"
+fi
# Add new hostkey (primary type) to sshd and connect
verbose "learn new primary hostkey"
-${SSHKEYGEN} -qt ssh-rsa -f $OBJ/hkr.ssh-rsa-new -N '' || fatal "ssh-keygen $k"
-( cat $OBJ/sshd_proxy.orig ; echo HostKey $OBJ/hkr.ssh-rsa-new ) \
+${SSHKEYGEN} -qt ${primary} -f $OBJ/hkr.${primary}-new -N '' || fatal "ssh-keygen ed25519"
+( cat $OBJ/sshd_proxy.orig ; echo HostKey $OBJ/hkr.${primary}-new ) \
> $OBJ/sshd_proxy
# Check new hostkey added
-dossh -oStrictHostKeyChecking=yes -oHostKeyAlgorithms=ssh-rsa,$all_algs
+dossh -oStrictHostKeyChecking=yes -oHostKeyAlgorithms=${primary},$all_algs
expect_nkeys `expr $nkeys + 1` "learn hostkeys"
-check_key_present ssh-rsa || fail "current key missing"
-check_key_present ssh-rsa $OBJ/hkr.ssh-rsa-new.pub || fail "new key missing"
+check_key_present ${primary} || fail "current key missing"
+check_key_present ${primary} $OBJ/hkr.${primary}-new.pub || fail "new key missing"
# Remove old hostkey (primary type) from sshd
verbose "rotate primary hostkey"
cp $OBJ/sshd_proxy.orig $OBJ/sshd_proxy
-mv $OBJ/hkr.ssh-rsa.pub $OBJ/hkr.ssh-rsa.pub.old
-mv $OBJ/hkr.ssh-rsa-new.pub $OBJ/hkr.ssh-rsa.pub
-mv $OBJ/hkr.ssh-rsa-new $OBJ/hkr.ssh-rsa
+mv $OBJ/hkr.${primary}.pub $OBJ/hkr.${primary}.pub.old
+mv $OBJ/hkr.${primary}-new.pub $OBJ/hkr.${primary}.pub
+mv $OBJ/hkr.${primary}-new $OBJ/hkr.${primary}
# Check old hostkey removed
-dossh -oStrictHostKeyChecking=yes -oHostKeyAlgorithms=ssh-rsa,$all_algs
+dossh -oStrictHostKeyChecking=yes -oHostKeyAlgorithms=${primary},$all_algs
expect_nkeys $nkeys "learn hostkeys"
-check_key_present ssh-rsa $OBJ/hkr.ssh-rsa.pub.old && fail "old key present"
-check_key_present ssh-rsa || fail "didn't learn changed key"
+check_key_present ${primary} $OBJ/hkr.${primary}.pub.old && fail "old key present"
+check_key_present ${primary} || fail "didn't learn changed key"
# Connect again, forcing rotated key
verbose "check rotate primary hostkey"
-dossh -oStrictHostKeyChecking=yes -oHostKeyAlgorithms=ssh-rsa
+dossh -oStrictHostKeyChecking=yes -oHostKeyAlgorithms=${primary}
expect_nkeys 1 "learn hostkeys"
-check_key_present ssh-rsa || fail "didn't learn changed key"
+check_key_present ${primary} || fail "didn't learn changed key"