Merge commit '86cc97e55fe346502462284d2e636a2b3708163e' as 'Sources/OpenVPN3'

Sources/OpenVPN3/openvpn/openssl/util/init.hpp

@@ -0,0 +1,39 @@
+//    OpenVPN -- An application to securely tunnel IP networks
+//               over a single port, with support for SSL/TLS-based
+//               session authentication and key exchange,
+//               packet encryption, packet authentication, and
+//               packet compression.
+//
+//    Copyright (C) 2012-2017 OpenVPN Inc.
+//
+//    This program is free software: you can redistribute it and/or modify
+//    it under the terms of the GNU Affero General Public License Version 3
+//    as published by the Free Software Foundation.
+//
+//    This program is distributed in the hope that it will be useful,
+//    but WITHOUT ANY WARRANTY; without even the implied warranty of
+//    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+//    GNU Affero General Public License for more details.
+//
+//    You should have received a copy of the GNU Affero General Public License
+//    along with this program in the COPYING file.
+//    If not, see <http://www.gnu.org/licenses/>.
+
+#pragma  once
+
+#include <openssl/opensslv.h>
+
+// OpenSSL 1.1.0 does not require an explicit init, in fact the
+// asio init for 1.1.0 is a noop, see also OPENSSL_init_ssl man page
+
+#if (OPENSSL_VERSION_NUMBER < 0x10100000L)
+#define OPENSSL_NEEDS_INIT
+
+// Instantiate this object to ensure openssl is initialised.
+#ifdef USE_ASIO
+#include <asio/ssl/detail/openssl_init.hpp>
+  typedef asio::ssl::detail::openssl_init<> openssl_init;
+#else
+  #error no OpenSSL init code (USE_ASIO needed for OpenSSL < 1.1)
+#endif
+#endif