--- /dev/null
+From e4bd17c86e01aaf6f809d9ea355419c86c4defdc Mon Sep 17 00:00:00 2001
+From: Max Fillinger <maximilian.fillinger@foxcrypto.com>
+Date: Mon, 12 Apr 2021 19:46:17 +0200
+Subject: [PATCH] Fix build with mbedtls w/o SSL renegotiation support
+
+In mbedtls, support for SSL renegotiation can be disabled at
+compile-time. However, OpenVPN cannot be built with such a library
+because it calls mbedtls_ssl_conf_renegotiation() to disable this
+feature at runtime. This function doesn't exist when mbedtls was built
+without support for SSL renegotiation.
+
+This commit fixes the build by ifdef'ing out the function call when
+mbedtls was built without support for SSL renegotiation.
+
+Signed-off-by: Max Fillinger <maximilian.fillinger@foxcrypto.com>
+Acked-by: Antonio Quartulli <antonio@openvpn.net>
+Message-Id: <E1lW0eX-00012w-9n@sfs-ml-1.v29.lw.sourceforge.com>
+URL: https://www.mail-archive.com/search?l=mid&q=E1lW0eX-00012w-9n@sfs-ml-1.v29.lw.sourceforge.com
+Signed-off-by: Gert Doering <gert@greenie.muc.de>
+---
+ src/openvpn/ssl_mbedtls.c | 9 ++++++---
+ 1 file changed, 6 insertions(+), 3 deletions(-)
+
+--- a/src/openvpn/ssl_mbedtls.c
++++ b/src/openvpn/ssl_mbedtls.c
+@@ -1098,10 +1098,13 @@ key_state_ssl_init(struct key_state_ssl
+ {
+ mbedtls_ssl_conf_curves(ks_ssl->ssl_config, ssl_ctx->groups);
+ }
+- /* Disable TLS renegotiations. OpenVPN's renegotiation creates new SSL
+- * session and does not depend on this feature. And TLS renegotiations have
+- * been problematic in the past */
++
++ /* Disable TLS renegotiations if the mbedtls library supports that feature.
++ * OpenVPN's renegotiation creates new SSL sessions and does not depend on
++ * this feature and TLS renegotiations have been problematic in the past. */
++#if defined(MBEDTLS_SSL_RENEGOTIATION)
+ mbedtls_ssl_conf_renegotiation(ks_ssl->ssl_config, MBEDTLS_SSL_RENEGOTIATION_DISABLED);
++#endif /* MBEDTLS_SSL_RENEGOTIATION */
+
+ /* Disable record splitting (for now). OpenVPN assumes records are sent
+ * unfragmented, and changing that will require thorough review and