Generate host keys in postinst only if the relevant HostKey directives are

found in sshd_config (closes: #87946).

2 files changed, 42 insertions, 9 deletions

diff --git a/debian/changelog b/debian/changelog
index a588623bd..5768423fe 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -4,6 +4,8 @@ openssh (1:3.8.1p1-6) UNRELEASED; urgency=low
     http://lists.debian.org/debian-boot/2004/07/msg01207.html to get
     openssh-client-udeb to show up as a retrievable debian-installer
     component.
+  * Generate host keys in postinst only if the relevant HostKey directives
+    are found in sshd_config (closes: #87946).
 
  -- Colin Watson <cjwatson@debian.org>  Mon, 19 Jul 2004 20:22:39 +0100
 
diff --git a/debian/postinst b/debian/postinst
index ac5e1c555..1baae1677 100644
--- a/debian/postinst
+++ b/debian/postinst
@@ -27,13 +27,45 @@ check_idea_key() {
 }
 
 
+get_config_option() {
+        option="$1"
+
+        # TODO: actually only one '=' allowed after option
+        perl -ne 'print if s/^[[:space:]]*'"$option"'[[:space:]=]+//i' \
+           /etc/ssh/sshd_config
+}
+
+
+host_keys_required() {
+        hostkeys="$(get_config_option HostKey)"
+        if [ "$hostkeys" ]; then
+                echo "$hostkeys"
+        else
+                # No HostKey directives at all, so the server picks some
+                # defaults depending on the setting of Protocol.
+                protocol="$(get_config_option Protocol)"
+                [ "$protocol" ] || protocol=1,2
+                if echo "$protocol" | grep 1 >/dev/null; then
+                        echo /etc/ssh/ssh_host_key
+                fi
+                if echo "$protocol" | grep 2 >/dev/null; then
+                        echo /etc/ssh/ssh_host_rsa_key
+                        echo /etc/ssh/ssh_host_dsa_key
+                fi
+        fi
+}
+
+
 create_key() {
         msg="$1"
         shift
+        hostkeys="$1"
+        shift
         file="$1"
         shift
 
-        if [ ! -f "$file" ] ; then
+        if echo "$hostkeys" | grep -x "$file" >/dev/null && \
+           [ ! -f "$file" ] ; then
                 echo -n $msg
                 ssh-keygen -q -f "$file" -N '' "$@"
                 echo
@@ -42,16 +74,15 @@ create_key() {
 
 
 create_keys() {
-        db_get ssh/protocol2_only
-        if [ "$RET" = "false" ] ; then
-                create_key "Creating SSH1 key; this may take some time ..." \
-                        /etc/ssh/ssh_host_key -t rsa1
-        fi
+        hostkeys="$(host_keys_required)"
+
+        create_key "Creating SSH1 key; this may take some time ..." \
+                "$hostkeys" /etc/ssh/ssh_host_key -t rsa1
 
         create_key "Creating SSH2 RSA key; this may take some time ..." \
-                /etc/ssh/ssh_host_rsa_key -t rsa
+                "$hostkeys" /etc/ssh/ssh_host_rsa_key -t rsa
         create_key "Creating SSH2 DSA key; this may take some time ..." \
-                /etc/ssh/ssh_host_dsa_key -t dsa
+                "$hostkeys" /etc/ssh/ssh_host_dsa_key -t dsa
 }
 
 
@@ -304,9 +335,9 @@ setup_init() {
         fi
 }
 
+create_sshdconfig
 check_idea_key
 create_keys
-create_sshdconfig
 fix_rsh_diversion
 fix_statoverride
 create_alternatives