Refactor extract_var_peer_info into standalone function and add ssl_util.c

Our "natural" place for this function would be ssl.c but ssl.c has a lot of
dependencies on all kinds of other compilation units so including ssl.c
into
unit tests is near impossible currently. Instead create a new file
ssl_util.c
that holds small utility functions like this one.

Patch v2: add newline add the end of sll_util.h and ssl_util.c

Patch v3: Refactor/clean up the function even more as suggested by Gert.

Signed-off-by: Arne Schwabe <arne@rfc2549.org>
Acked-by: Lev Stipakov <lstipakov@gmail.com>
Acked-by: Gert Doering <gert@greenie.muc.de>
Message-Id: <20210226111012.21269-1-arne@rfc2549.org>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg21585.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>

1 files changed, 49 insertions, 0 deletions

diff --git a/src/openvpn/ssl_util.h b/src/openvpn/ssl_util.h
new file mode 100644
index 0000000..bc2ae30
--- /dev/null
+++ b/src/openvpn/ssl_util.h
@@ -0,0 +1,49 @@
+/*
+ *  OpenVPN -- An application to securely tunnel IP networks
+ *             over a single TCP/UDP port, with support for SSL/TLS-based
+ *             session authentication and key exchange,
+ *             packet encryption, packet authentication, and
+ *             packet compression.
+ *
+ *  Copyright (C) 2002-2020 OpenVPN Inc <sales@openvpn.net>
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2
+ *  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 General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with this program; if not, write to the Free Software Foundation, Inc.,
+ *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+/**
+ * @file SSL utility function. This file (and its .c file) is designed to
+ *       to be included in units/etc without pulling in a lot of dependencies
+ */
+
+#ifndef SSL_UTIL_H_
+#define SSL_UTIL_H_
+
+#include "buffer.h"
+
+/**
+ * Extracts a variable from peer info, the returned string will be allocated
+ * using the supplied gc_arena
+ *
+ * @param peer_info     The peer's peer_info
+ * @param var           The variable *including* =, e.g. IV_CIPHERS=
+ *
+ * @return  The content of the variable as NULL terminated string or NULL if the
+ *          variable cannot be found.
+ */
+char *
+extract_var_peer_info(const char *peer_info,
+                      const char *var,
+                      struct gc_arena *gc);
+
+#endif