From 19f2cbf0e7066753476ff8c38c07a6f0df73a622 Mon Sep 17 00:00:00 2001
From: Michael Zillgith <michael.zillgith@mz-automation.de>
Date: Sat, 30 Jan 2021 16:50:01 +0100
Subject: [PATCH] - CMake build: add new configuration option
 CONFIG_USE_EXTERNAL_MBEDTLS_DYNLIB to allow build using externally built
 mbedtls DLL/shared object

---
 CMakeLists.txt     | 12 ++++++++++++
 hal/CMakeLists.txt | 17 +++++++++++++----
 2 files changed, 25 insertions(+), 4 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 31c84c23..50c7a7c7 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -36,6 +36,11 @@ option(CONFIG_MMS_THREADLESS_STACK "Optimize stack for threadless operation (war
 option(CONFIG_ACTIVATE_TCP_KEEPALIVE "Activate TCP keepalive" ON)
 option(CONFIG_INCLUDE_GOOSE_SUPPORT "Build with GOOSE support" ON)
 
+option(CONFIG_USE_EXTERNAL_MBEDTLS_DYNLIB "Build with pre-compiled mbedtls dynamic library" OFF)
+
+set(CONFIG_EXTERNAL_MBEDTLS_DYNLIB_PATH "${CMAKE_CURRENT_LIST_DIR}/third_party/mbedtls/mbedtls-2.16/library" CACHE STRING "Path to search for the mbedtls dynamic libraries" )
+set(CONFIG_EXTERNAL_MBEDTLS_INCLUDE_PATH "${CMAKE_CURRENT_LIST_DIR}/third_party/mbedtls/mbedtls-2.16/include" CACHE STRING "Path to search for the mbedtls include files" )
+
 # choose the library features which shall be included
 option(CONFIG_IEC61850_CONTROL_SERVICE "Build with support for IEC 61850 control features" ON)
 option(CONFIG_IEC61850_REPORT_SERVICE "Build with support for IEC 61850 reporting services" ON)
@@ -114,8 +119,15 @@ if(MSVC AND MSVC_VERSION LESS 1800)
     )
 endif(MSVC AND MSVC_VERSION LESS 1800)
 
+if(CONFIG_USE_EXTERNAL_MBEDTLS_DYNLIB)
+set(WITH_MBEDTLS 1)
+set(USE_PREBUILD_MBEDTLS 1)
+set(MBEDTLS_INCLUDE_DIR ${CONFIG_EXTERNAL_MBEDTLS_INCLUDE_PATH})
+endif(CONFIG_USE_EXTERNAL_MBEDTLS_DYNLIB)
+
 if(EXISTS ${CMAKE_CURRENT_LIST_DIR}/third_party/mbedtls/mbedtls-2.16)
 set(WITH_MBEDTLS 1)
+set(MBEDTLS_INCLUDE_DIR "${CMAKE_CURRENT_LIST_DIR}/third_party/mbedtls/mbedtls-2.16/include")
 endif(EXISTS ${CMAKE_CURRENT_LIST_DIR}/third_party/mbedtls/mbedtls-2.16)
 
 if(WITH_MBEDTLS)
diff --git a/hal/CMakeLists.txt b/hal/CMakeLists.txt
index b50f9937..2ca0ea94 100644
--- a/hal/CMakeLists.txt
+++ b/hal/CMakeLists.txt
@@ -115,18 +115,22 @@ ENDIF(WIN32)
 #set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fPIC" )
 #set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fPIC" )
 
-if(EXISTS ${CMAKE_CURRENT_LIST_DIR}/../third_party/mbedtls/mbedtls-2.16)
-message("Found mbedtls -> can compile with TLS support")
+if(WITH_MBEDTLS)
+message("Found mbedtls -> can compile HAL with TLS support")
 set(WITH_MBEDTLS 1)
-endif(EXISTS ${CMAKE_CURRENT_LIST_DIR}/../third_party/mbedtls/mbedtls-2.16)
+endif(WITH_MBEDTLS)
 
 if(WITH_MBEDTLS)
 include_directories(
 	${CMAKE_CURRENT_LIST_DIR}/tls/mbedtls
-    ${CMAKE_CURRENT_LIST_DIR}/../third_party/mbedtls/mbedtls-2.16/include
+    ${MBEDTLS_INCLUDE_DIR}
 )
 
+if(CONFIG_USE_EXTERNAL_MBEDTLS_DYNLIB)
+link_directories(${CONFIG_EXTERNAL_MBEDTLS_DYNLIB_PATH})
+else()
 file(GLOB tls_SRCS ${CMAKE_CURRENT_LIST_DIR}/../third_party/mbedtls/mbedtls-2.16/library/*.c)
+endif(CONFIG_USE_EXTERNAL_MBEDTLS_DYNLIB)
 
 add_definitions(-DMBEDTLS_CONFIG_FILE="mbedtls_config.h")
 
@@ -165,6 +169,11 @@ IF(UNIX)
      )
   ENDIF (CONFIG_SYSTEM_HAS_CLOCK_GETTIME)
 ENDIF(UNIX)
+
+IF(CONFIG_USE_EXTERNAL_MBEDTLS_DYNLIB)
+  target_link_libraries(hal mbedcrypto mbedx509 mbedtls)
+ENDIF(CONFIG_USE_EXTERNAL_MBEDTLS_DYNLIB)
+
 IF(MINGW)
   target_link_libraries(hal ws2_32 iphlpapi)
 ENDIF(MINGW)