check config file permissions before sourcing

pbc

@@ -264,6 +264,12 @@ while (( $# > 0 )); do
 done
 
 
+if [ -f "$cfgfile" ]; then
+  perms=$(stat -c '%a' "$cfgfile")
+  (( 8#$perms & 0022 )) && echo "Error: $cfgfile is writable by group or others!" >&2 && exit 202
+  (( 8#$perms & 0007 )) && echo "Warning: $cfgfile is readable by others!" >&2
+fi
+
 if $FULL_HELP; then
   [ -f "$cfgfile" ] && source "$cfgfile"
   PBC=${PBC:-/usr/local/bin/proxmox-backup-client}
@@ -280,6 +286,8 @@ if [ "$action" == 'install' ]; then
     ! command -v "$exe" >/dev/null && echo "Error: $exe executable not found!" >&2 && exit 200
   done
 else
+  [ ! -f "$cfgfile" ] && echo "Error: $cfgfile: no such file" >&2 && exit 201
+  [ ! -r "$cfgfile" ] && echo "Error: $cfgfile: not readable" >&2 && exit 201
   source "$cfgfile" || exit $?
   PBC=${PBC:-/usr/local/bin/proxmox-backup-client}
   [ ! -f "$PBC" ] && echo "Error: $PBC: no such file" >&2 && exit 200