classes/image: improve debug-tweaks ssh server configuration

Create a single postprocessing function that enables no-password logins
for both openssh and dropbear when debug-tweaks is in IMAGE_FEATURES,
changing its behaviour slightly:
* Run it regardless of whether ssh-server-* are in IMAGE_FEATURES so
  that it still takes effect if these are installed by adding
  dropbear/openssh to IMAGE_INSTALL.
* Enable it to be run from image.bbclass rather than core-image.bbclass
  so that it works for images that are using the former.

Second half of the fix for [YOCTO #2578].

(From OE-Core rev: 0937054e6e3e02565f57e60a8bdc14b0ad62e249)

Signed-off-by: Paul Eggleton <paul.eggleton@linux.intel.com>
Signed-off-by: Saul Wold <sgw@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

2 files changed, 14 insertions, 5 deletions

diff --git a/meta/classes/core-image.bbclass b/meta/classes/core-image.bbclass
index 2e67018536..e0f6dbb7d9 100644
--- a/meta/classes/core-image.bbclass
+++ b/meta/classes/core-image.bbclass
@@ -76,6 +76,3 @@ ROOTFS_POSTPROCESS_COMMAND += "rootfs_update_timestamp ; "
 
 # Zap the root password if debug-tweaks feature is not enabled
 ROOTFS_POSTPROCESS_COMMAND += '${@base_contains("IMAGE_FEATURES", "debug-tweaks", "", "zap_root_password ; ",d)}'
-# Allow openssh accept empty password login if both debug-tweaks and ssh-server-openssh are enabled
-ROOTFS_POSTPROCESS_COMMAND += '${@base_contains("IMAGE_FEATURES", "debug-tweaks ssh-server-openssh", "openssh_allow_empty_password; ", "",d)}'
-
diff --git a/meta/classes/image.bbclass b/meta/classes/image.bbclass
index e49468949e..0293d2e358 100644
--- a/meta/classes/image.bbclass
+++ b/meta/classes/image.bbclass
@@ -167,6 +167,8 @@ inherit ${IMAGE_CLASSES}
 IMAGE_POSTPROCESS_COMMAND ?= ""
 MACHINE_POSTPROCESS_COMMAND ?= ""
 ROOTFS_POSTPROCESS_COMMAND_prepend = "run_intercept_scriptlets; "
+# Allow dropbear/openssh to accept logins from accounts with an empty password string if debug-tweaks is enabled
+ROOTFS_POSTPROCESS_COMMAND += '${@base_contains("IMAGE_FEATURES", "debug-tweaks", "ssh_allow_empty_password; ", "",d)}'
 
 # some default locales
 IMAGE_LINGUAS ?= "de-de fr-fr en-gb"
@@ -396,12 +398,22 @@ zap_root_password () {
         mv ${IMAGE_ROOTFS}/etc/passwd.new ${IMAGE_ROOTFS}/etc/passwd
 } 
 
-# allow openssh accept login with empty password string
-openssh_allow_empty_password () {
+# allow dropbear/openssh to accept root logins and logins from accounts with an empty password string
+ssh_allow_empty_password () {
         if [ -e ${IMAGE_ROOTFS}${sysconfdir}/ssh/sshd_config ]; then
                 sed -i 's#.*PermitRootLogin.*#PermitRootLogin yes#' ${IMAGE_ROOTFS}${sysconfdir}/ssh/sshd_config
                 sed -i 's#.*PermitEmptyPasswords.*#PermitEmptyPasswords yes#' ${IMAGE_ROOTFS}${sysconfdir}/ssh/sshd_config
         fi
+
+        if [ -e ${IMAGE_ROOTFS}${sbindir}/dropbear ] ; then
+                if grep -q DROPBEAR_EXTRA_ARGS ${IMAGE_ROOTFS}${sysconfdir}/default/dropbear 2>/dev/null ; then
+                        if ! grep -q "DROPBEAR_EXTRA_ARGS=.*-B" ${IMAGE_ROOTFS}${sysconfdir}/default/dropbear ; then
+                                sed -i 's/^DROPBEAR_EXTRA_ARGS="*\([^"]*\)"*/DROPBEAR_EXTRA_ARGS="\1 -B"/' ${IMAGE_ROOTFS}${sysconfdir}/default/dropbear
+                        fi
+                else
+                        printf '\nDROPBEAR_EXTRA_ARGS="-B"\n' >> ${IMAGE_ROOTFS}${sysconfdir}/default/dropbear
+                fi
+        fi
 }
 
 # Turn any symbolic /sbin/init link into a file