Add to an Existing Project¶

We recommend adding Libtropic to an existing project as a git submodule. Libtropic uses the CMake build system, so it can be added to the compilation of existing CMake projects as follows:

1. Set path to the Libtropic submodule, for example as:

   set(PATH_LIBTROPIC ${CMAKE_CURRENT_SOURCE_DIR}/../vendor/libtropic/)
   

2. Add the Libtropic subdirectory:

   add_subdirectory(${PATH_LIBTROPIC} "libtropic")
   

3. By default, Libtropic does not link a CFP (Cryptographic Functionality Provider) or its CAL (Crypto Abstraction Layer), so it can be built as a static library. This is the consumer's responsibility:
   1. For the chosen CFP (e.g. MbedTLS v4.0.0), add the correct subdirectory inside libtropic/cal/, which provides the corresponding CAL sources and include directories:

      add_subdirectory("${PATH_LIBTROPIC}cal/mbedtls_v4")
      

   2. Add the obtained sources and include directories to the tropic target:

      target_sources(tropic PRIVATE ${LT_CAL_SRCS})
      target_include_directories(tropic PUBLIC ${LT_CAL_INC_DIRS})
      

   3. Link the CFP (provided by the consumer) to the tropic target:

      target_link_libraries(tropic PUBLIC mbedtls)
      

4. By default, libtropic does not link platform-specific code or its HAL, so it can be built as a static library. This is the consumer's responsibility:
   1. For the chosen platform (e.g. Linux with HW SPI), add a corresponding HAL using add_subdirectory:

      add_subdirectory("${PATH_TO_LIBTROPIC}hal/linux/spi")
      

   2. Add HAL sources and include directories to the tropic target. In the previous step, LT_HAL_SRCS and LT_HAL_INC_DIRS variables were populated based on the selected HAL, so you can use those:

      target_sources(tropic PRIVATE ${LT_HAL_SRCS})
      target_include_directories(tropic PUBLIC ${LT_HAL_INC_DIRS})
      

5. And finally, link Libtropic with your binary:

   target_link_libraries(my_binary_name PRIVATE tropic)
   

Do You Use a Makefile Instead of CMake?¶

If you use a Makefile instead of CMake, you need to:

1. Manually list all *.c and *.h Libtropic files in your Makefile (you can use the root CMakeLists.txt for inspiration).
2. For each required CMake option <CMAKE_OPTION>, add the -D<CMAKE_OPTION> flag when building with Make.