Modified to support separate usher for client and server packages

SNAP/usher-server

@@ -0,0 +1,66 @@
+#!/bin/bash
+
+set -e
+
+case $1 in
+  preinst)
+    exit 0
+    ;;
+  postinst)
+    if [[ ${TARGET} ]]; then
+      if ! chroot ${TARGET} 'getent group sshd 2>&1' > /dev/null; then
+        if chroot ${TARGET} 'groupadd -g 50 sshd'; then
+          echo 'Created group sshd'
+        else
+          echo 'Failed to create group sshd!'
+          exit 1
+        fi
+      fi
+      if ! chroot ${TARGET} 'getent passwd sshd 2>&1 > /dev/null'; then
+        if chroot ${TARGET} 'useradd -c "sshd PrivSep" \
+        -d /var/run/sshd -g sshd -s /bin/false -u 50 sshd'; then
+          echo 'Created user sshd'
+        else
+          echo 'Failed to create user sshd!'
+          exit 1
+        fi
+      fi
+
+      if [ ! -f ${TARGET}/etc/ssh/ssh_host_rsa_key ]; then
+        chroot ${TARGET} 'ssh-keygen -A'
+      fi
+    else
+      if ! getent group sshd 2>&1 > /dev/null; then
+        if groupadd -g 50 sshd; then
+          echo 'Created group sshd'
+        else
+          echo 'Failed to create group sshd!'
+          exit 1
+        fi
+      fi
+      if ! getent passwd sshd 2>&1 > /dev/null; then
+        if useradd -c 'sshd PrivSep' -d /var/run/sshd -g sshd \
+        -s /bin/false -u 50 sshd; then
+          echo 'Created user sshd'
+        else
+          echo 'Failed to create user sshd!'
+          exit 1
+        fi
+      fi
+
+      if [ ! -f /etc/ssh/ssh_host_rsa_key ]; then
+        ssh-keygen -A
+      fi
+    fi
+
+    if [ ! -f ${TARGET}/etc/ssh/sshd_config ]; then
+      cp ${TARGET}/usr/share/openssh/sshd_config ${TARGET}/etc/ssh
+    fi
+    ;;
+  prerm)
+    exit 0
+    ;;
+  postrm)
+    exit 0
+    ;;
+esac