openbsd: finish password changing

openbsd/FEATURES

@@ -4,5 +4,5 @@ ipv6:		ok
 hostname:	?
 time:		ok
 smb:		ok
-passwd update:	?
+passwd update:	ok
 get-ssh-keys:	ok

openbsd/_openbsdcontext.py

@@ -70,14 +70,18 @@ class Context(BaseContext):
         libc.clock_settime(CLOCK_REALTIME, ctypes.byref(ts))
 
     @staticmethod
-    def change_password(password):
-        # TODO: root password
+    def _change_user_password(username, password):
         enc_proc = subprocess.Popen(
             ['/usr/bin/encrypt'],
             stdin=subprocess.PIPE, stdout=subprocess.PIPE)
         enc_password, _ = enc_proc.communicate('%s\n' % password)
         subprocess.Popen(
-            ['/usr/sbin/usermod', '-p', enc_password.strip(), 'cloud'])
+            ['/usr/sbin/usermod', '-p', enc_password.strip(), username])
+
+    @staticmethod
+    def change_password(password):
+        Context._change_user_password('cloud', password)
+        Context._change_user_password('root', password)
 
     @staticmethod
     def restart_networking():