@@ -271,6 +271,11 @@ User-visible Changes

   /etc/openvpn/client (depending on unit file).  This also avoids these new

   unit files and how they work to collide with older pre-existing unit files.

+- using ``--no-iv`` (which is generally not a recommended setup) will

+  require explicitly disabling NCP with ``--disable-ncp``.  This is

+  intentional because NCP will by default use AES-GCM, which requires

+  an IV - so we want users of that option to consciously reconsider.

+

 Maintainer-visible changes

 --------------------------

@@ -2341,9 +2341,9 @@ do_init_crypto_tls (struct context *c, const unsigned int flags)

   if (options->mute_replay_warnings)

     to.crypto_flags |= CO_MUTE_REPLAY_WARNINGS;

-  to.crypto_flags_and = ~(CO_PACKET_ID_LONG_FORM);

+  to.crypto_flags &= ~(CO_PACKET_ID_LONG_FORM);

   if (packet_id_long_form)

-    to.crypto_flags_or = CO_PACKET_ID_LONG_FORM;

+    to.crypto_flags |= CO_PACKET_ID_LONG_FORM;

   to.ssl_ctx = c->c1.ks.ssl_ctx;

   to.key_type = c->c1.ks.key_type;

@@ -2234,6 +2234,10 @@ options_postprocess_verify_ce (const struct options *options, const struct conne

     {

       msg (M_USAGE, "NCP cipher list contains unsupported ciphers.");

     }

+  if (options->ncp_enabled && !options->use_iv)

+    {

+      msg (M_USAGE, "--no-iv not allowed when NCP is enabled.");

+    }

   /*

    * Check consistency of replay options

@@ -881,9 +881,6 @@ key_state_init (struct tls_session *session, struct key_state *ks)

     }

   ks->crypto_options.pid_persist = NULL;

-  ks->crypto_options.flags = session->opt->crypto_flags;

-  ks->crypto_options.flags &= session->opt->crypto_flags_and;

-  ks->crypto_options.flags |= session->opt->crypto_flags_or;

 #ifdef MANAGEMENT_DEF_AUTH

   ks->mda_key_id = session->opt->mda_context->mda_key_id_counter++;

@@ -1823,6 +1820,7 @@ tls_session_generate_data_channel_keys(struct tls_session *session)

   ASSERT (ks->authenticated);

+  ks->crypto_options.flags = session->opt->crypto_flags;

   if (!generate_key_expansion (&ks->crypto_options.key_ctx_bi,

       &session->opt->key_type, ks->key_src, client_sid, server_sid,

       session->opt->server))

@@ -1857,9 +1855,9 @@ tls_session_update_crypto_params(struct tls_session *session,

       options->authname, options->keysize, true, true);

   bool packet_id_long_form = cipher_kt_mode_ofb_cfb (session->opt->key_type.cipher);

-  session->opt->crypto_flags_and &= ~(CO_PACKET_ID_LONG_FORM);

+  session->opt->crypto_flags &= ~(CO_PACKET_ID_LONG_FORM);

   if (packet_id_long_form)

-    session->opt->crypto_flags_and = CO_PACKET_ID_LONG_FORM;

+    session->opt->crypto_flags |= CO_PACKET_ID_LONG_FORM;

   /* Update frame parameters: undo worst-case overhead, add actual overhead */

   frame_add_to_extra_frame (frame, -(crypto_max_overhead()));

@@ -279,8 +279,6 @@ struct tls_options

   /* struct crypto_option flags */

   unsigned int crypto_flags;

-  unsigned int crypto_flags_and;

-  unsigned int crypto_flags_or;

   int replay_window;                   /* --replay-window parm */

   int replay_time;                     /* --replay-window parm */