Ticket #845: 0001-Allow-changing-cipher-from-a-ccd-file.patch

src/openvpn/multi.c

@@ -2086 +2086 @@
             mi->context.c2.context_auth = cc_succeeded_count ? CAS_PARTIAL : CAS_FAILED;
         }
 
+        /* Generate tunnel keys, unless IV_NCP >= 2 is negotiated. The first key
+         * generation is then postponed until after the pull/push, so we can
+         * process pushed cipher directives.
+         */
+        struct tls_session *session = &mi->context.c2.tls_multi->session[TM_ACTIVE];
+        struct key_state *ks = &session->key[KS_PRIMARY];
+        if (!session->opt->ncp_enabled && ks->authenticated
+            && !tls_session_update_crypto_params(session, &mi->context.options,
+                                                 &mi->context.c2.frame))
+        {
+            msg(D_TLS_ERRORS, "TLS Error: server generate_key_expansion failed");
+            cc_succeeded = false;
+        }
+
         /* set flag so we don't get called again */
         mi->connection_established_flag = true;
 

src/openvpn/options.c

@@ -7536 +7536 @@
     }
     else if (streq(p[0], "cipher") && p[1] && !p[2])
     {
-        VERIFY_PERMISSION(OPT_P_NCP);
+        VERIFY_PERMISSION(OPT_P_NCP|OPT_P_INSTANCE);
         options->ciphername = p[1];
     }
     else if (streq(p[0], "ncp-ciphers") && p[1] && !p[2])

src/openvpn/options.h

@@ -628 +628 @@
 #define OPT_P_MTU             (1<<14) /* TODO */
 #define OPT_P_NICE            (1<<15)
 #define OPT_P_PUSH            (1<<16)
-#define OPT_P_INSTANCE        (1<<17)
+#define OPT_P_INSTANCE        (1<<17) /**< Allow usage in ccd file */
 #define OPT_P_CONFIG          (1<<18)
 #define OPT_P_EXPLICIT_NOTIFY (1<<19)
 #define OPT_P_ECHO            (1<<20)

src/openvpn/ssl.c

@@ -2401 +2401 @@
     }
 
     /* Generate tunnel keys if we're a TLS server.
-     * If we're a p2mp server and IV_NCP >= 2 is negotiated, the first key
-     * generation is postponed until after the pull/push, so we can process pushed
-     * cipher directives.
+     * If we're a p2mp server, the first key generation is postponed so we can
+     * switch cipher during the connection setup phase.
      */
-    if (session->opt->server && !(session->opt->ncp_enabled
-                                  && session->opt->mode == MODE_SERVER && ks->key_id <= 0))
+    if (session->opt->server
+        && !(session->opt->mode == MODE_SERVER && ks->key_id <= 0))
     {
         if (ks->authenticated)
         {