ssl_test_lib.[hc]: new source file for common SSL test code

Create a new source file for code that is shared between ssl_client2.c
and ssl_server2.c. This commit only creates the file; subsequent
commits will populate it.

Add it to the official build systems (make, cmake, VS).

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
diff --git a/programs/ssl/CMakeLists.txt b/programs/ssl/CMakeLists.txt
index 149aa30..e4038f7 100644
--- a/programs/ssl/CMakeLists.txt
+++ b/programs/ssl/CMakeLists.txt
@@ -32,8 +32,10 @@
     target_include_directories(${exe} PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/../../tests/include)
 endforeach()
 
-set_property(TARGET ssl_client2 APPEND PROPERTY SOURCES ${CMAKE_CURRENT_SOURCE_DIR}/../test/query_config.c)
-set_property(TARGET ssl_server2 APPEND PROPERTY SOURCES ${CMAKE_CURRENT_SOURCE_DIR}/../test/query_config.c)
+set_property(TARGET ssl_client2 APPEND PROPERTY SOURCES
+    ssl_test_lib.c ${CMAKE_CURRENT_SOURCE_DIR}/../test/query_config.c)
+set_property(TARGET ssl_server2 APPEND PROPERTY SOURCES
+    ssl_test_lib.c ${CMAKE_CURRENT_SOURCE_DIR}/../test/query_config.c)
 
 if(THREADS_FOUND)
     add_executable(ssl_pthread_server ssl_pthread_server.c $<TARGET_OBJECTS:mbedtls_test>)
diff --git a/programs/ssl/ssl_test_lib.c b/programs/ssl/ssl_test_lib.c
new file mode 100644
index 0000000..e3645f3
--- /dev/null
+++ b/programs/ssl/ssl_test_lib.c
@@ -0,0 +1,21 @@
+/*
+ *  Common code for SSL test programs
+ *
+ *  Copyright The Mbed TLS Contributors
+ *  SPDX-License-Identifier: Apache-2.0
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License"); you may
+ *  not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+
+#include "ssl_test_lib.h"
+
diff --git a/programs/ssl/ssl_test_lib.h b/programs/ssl/ssl_test_lib.h
new file mode 100644
index 0000000..07c784c
--- /dev/null
+++ b/programs/ssl/ssl_test_lib.h
@@ -0,0 +1,23 @@
+/*
+ *  Common code for SSL test programs
+ *
+ *  Copyright The Mbed TLS Contributors
+ *  SPDX-License-Identifier: Apache-2.0
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License"); you may
+ *  not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+
+#ifndef MBEDTLS_PROGRAMS_SSL_SSL_TEST_LIB_H
+#define MBEDTLS_PROGRAMS_SSL_SSL_TEST_LIB_H
+
+#endif /* MBEDTLS_PROGRAMS_SSL_SSL_TEST_LIB_H */