unit-tests: Add mock DH implementation that's basically a noop

If the openssl plugin is built DH isn't that much of an overhead as
ecp256 is used, but the default MODP group is now modp3072.

src/libcharon/tests/Makefile.am

@@ -27,6 +27,7 @@ exchange_tests_SOURCES = \
   suites/test_child_delete.c \
   utils/exchange_test_asserts.h utils/exchange_test_asserts.c \
   utils/exchange_test_helper.h utils/exchange_test_helper.c \
+  utils/mock_dh.h utils/mock_dh.c \
   utils/mock_ipsec.h utils/mock_ipsec.c \
   utils/mock_sender.h utils/mock_sender.c \
   utils/sa_asserts.h \

src/libcharon/tests/utils/mock_dh.c

@@ -0,0 +1,87 @@
+/*
+ * Copyright (C) 2016 Tobias Brunner
+ * Copyright (C) 2008 Martin Willi
+ * HSR Hochschule fuer Technik Rapperswil
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
+ *
+ * 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.
+ */
+
+#include "mock_dh.h"
+
+typedef struct private_diffie_hellman_t private_diffie_hellman_t;
+
+/**
+ * Private data
+ */
+struct private_diffie_hellman_t {
+
+	/**
+	 * Public interface
+	 */
+	diffie_hellman_t public;
+
+	/**
+	 * Instantiated DH group
+	 */
+	diffie_hellman_group_t group;
+};
+
+METHOD(diffie_hellman_t, get_my_public_value, bool,
+	private_diffie_hellman_t *this, chunk_t *value)
+{
+	*value = chunk_empty;
+	return TRUE;
+}
+
+METHOD(diffie_hellman_t, set_other_public_value, bool,
+	private_diffie_hellman_t *this, chunk_t value)
+{
+	return TRUE;
+}
+
+METHOD(diffie_hellman_t, get_shared_secret, bool,
+	private_diffie_hellman_t *this, chunk_t *secret)
+{
+	*secret = chunk_empty;
+	return TRUE;
+}
+
+METHOD(diffie_hellman_t, get_dh_group, diffie_hellman_group_t,
+	private_diffie_hellman_t *this)
+{
+	return this->group;
+}
+
+METHOD(diffie_hellman_t, destroy, void,
+	private_diffie_hellman_t *this)
+{
+	free(this);
+}
+
+/**
+ * See header
+ */
+diffie_hellman_t *mock_dh_create(diffie_hellman_group_t group)
+{
+	private_diffie_hellman_t *this;
+
+	INIT(this,
+		.public = {
+			.get_shared_secret = _get_shared_secret,
+			.set_other_public_value = _set_other_public_value,
+			.get_my_public_value = _get_my_public_value,
+			.get_dh_group = _get_dh_group,
+			.destroy = _destroy,
+		},
+		.group = group,
+	);
+	return &this->public;
+}

src/libcharon/tests/utils/mock_dh.h

@@ -0,0 +1,37 @@
+/*
+ * Copyright (C) 2016 Tobias Brunner
+ * HSR Hochschule fuer Technik Rapperswil
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
+ *
+ * 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.
+ */
+
+/**
+ * Provides a DH implementation that does no real work to make the tests run
+ * faster.
+ *
+ * @defgroup mock_dh mock_dh
+ * @{ @ingroup test_utils_c
+ */
+
+#ifndef MOCK_DH_H_
+#define MOCK_DH_H_
+
+#include <crypto/diffie_hellman.h>
+
+/**
+ * Creates a diffie_hellman_t object.
+ *
+ * @param group			Diffie Hellman group, supports MODP_NULL only
+ * @return				created object
+ */
+diffie_hellman_t *mock_dh_create(diffie_hellman_group_t group);
+
+#endif /** MOCK_DH_H_ @}*/