Add mbedtls as an alternative to OpenSSL, plan to implement TLS connections later

cmake/FindmbedTLS.cmake

@@ -0,0 +1,93 @@
+# - Try to find mbedTLS
+# Once done this will define
+#
+# Read-Only variables
+#  MBEDTLS_FOUND - system has mbedTLS
+#  MBEDTLS_INCLUDE_DIR - the mbedTLS include directory
+#  MBEDTLS_LIBRARY_DIR - the mbedTLS library directory
+#  MBEDTLS_LIBRARIES - Link these to use mbedTLS
+#  MBEDTLS_LIBRARY - path to mbedTLS library
+#  MBEDX509_LIBRARY - path to mbedTLS X.509 library
+#  MBEDCRYPTO_LIBRARY - path to mbedTLS Crypto library
+#
+# Hint
+#  MBEDTLS_ROOT_DIR can be pointed to a local mbedTLS installation.
+
+SET(_MBEDTLS_ROOT_HINTS
+    ${MBEDTLS_ROOT_DIR}
+    ENV MBEDTLS_ROOT_DIR
+)
+
+SET(_MBEDTLS_ROOT_HINTS_AND_PATHS
+    HINTS ${_MBEDTLS_ROOT_HINTS}
+    PATHS ${_MBEDTLS_ROOT_PATHS}
+)
+
+FIND_PATH(MBEDTLS_INCLUDE_DIR
+    NAMES mbedtls/version.h
+    ${_MBEDTLS_ROOT_HINTS_AND_PATHS}
+    PATH_SUFFIXES include
+)
+
+IF(MBEDTLS_INCLUDE_DIR AND MBEDTLS_LIBRARIES)
+    # Already in cache, be silent
+    SET(MBEDTLS_FIND_QUIETLY TRUE)
+ENDIF()
+
+FIND_LIBRARY(MBEDTLS_LIBRARY
+    NAMES mbedtls libmbedtls
+    ${_MBEDTLS_ROOT_HINTS_AND_PATHS}
+    PATH_SUFFIXES library
+)
+FIND_LIBRARY(MBEDX509_LIBRARY
+    NAMES mbedx509 libmbedx509
+    ${_MBEDTLS_ROOT_HINTS_AND_PATHS}
+    PATH_SUFFIXES library
+)
+FIND_LIBRARY(MBEDCRYPTO_LIBRARY
+    NAMES mbedcrypto libmbedcrypto
+    ${_MBEDTLS_ROOT_HINTS_AND_PATHS}
+    PATH_SUFFIXES library
+)
+
+IF(MBEDTLS_INCLUDE_DIR AND MBEDTLS_LIBRARY AND MBEDX509_LIBRARY AND MBEDCRYPTO_LIBRARY)
+     SET(MBEDTLS_FOUND TRUE)
+ENDIF()
+
+IF(MBEDTLS_FOUND)
+    # split mbedTLS into -L and -l linker options, so we can set them for pkg-config
+    GET_FILENAME_COMPONENT(MBEDTLS_LIBRARY_DIR ${MBEDTLS_LIBRARY} PATH)
+    GET_FILENAME_COMPONENT(MBEDTLS_LIBRARY_FILE ${MBEDTLS_LIBRARY} NAME_WE)
+    GET_FILENAME_COMPONENT(MBEDX509_LIBRARY_FILE ${MBEDX509_LIBRARY} NAME_WE)
+    GET_FILENAME_COMPONENT(MBEDCRYPTO_LIBRARY_FILE ${MBEDCRYPTO_LIBRARY} NAME_WE)
+    STRING(REGEX REPLACE "^lib" "" MBEDTLS_LIBRARY_FILE ${MBEDTLS_LIBRARY_FILE})
+    STRING(REGEX REPLACE "^lib" "" MBEDX509_LIBRARY_FILE ${MBEDX509_LIBRARY_FILE})
+    STRING(REGEX REPLACE "^lib" "" MBEDCRYPTO_LIBRARY_FILE ${MBEDCRYPTO_LIBRARY_FILE})
+    SET(MBEDTLS_LIBRARIES "-L${MBEDTLS_LIBRARY_DIR} -l${MBEDTLS_LIBRARY_FILE} -l${MBEDX509_LIBRARY_FILE} -l${MBEDCRYPTO_LIBRARY_FILE}")
+
+    IF(NOT MBEDTLS_FIND_QUIETLY)
+        MESSAGE(STATUS "Found mbedTLS:")
+        FILE(READ ${MBEDTLS_INCLUDE_DIR}/mbedtls/version.h MBEDTLSCONTENT)
+        STRING(REGEX MATCH "MBEDTLS_VERSION_STRING +\"[0-9|.]+\"" MBEDTLSMATCH ${MBEDTLSCONTENT})
+        IF (MBEDTLSMATCH)
+            STRING(REGEX REPLACE "MBEDTLS_VERSION_STRING +\"([0-9|.]+)\"" "\\1" MBEDTLS_VERSION ${MBEDTLSMATCH})
+            MESSAGE(STATUS "  version ${MBEDTLS_VERSION}")
+        ENDIF(MBEDTLSMATCH)
+        MESSAGE(STATUS "  TLS: ${MBEDTLS_LIBRARY}")
+        MESSAGE(STATUS "  X509: ${MBEDX509_LIBRARY}")
+        MESSAGE(STATUS "  Crypto: ${MBEDCRYPTO_LIBRARY}")
+    ENDIF(NOT MBEDTLS_FIND_QUIETLY)
+ELSE(MBEDTLS_FOUND)
+    IF(MBEDTLS_FIND_REQUIRED)
+        MESSAGE(FATAL_ERROR "Could not find mbedTLS")
+    ENDIF(MBEDTLS_FIND_REQUIRED)
+ENDIF(MBEDTLS_FOUND)
+
+MARK_AS_ADVANCED(
+    MBEDTLS_INCLUDE_DIR
+    MBEDTLS_LIBRARY_DIR
+    MBEDTLS_LIBRARIES
+    MBEDTLS_LIBRARY
+    MBEDX509_LIBRARY
+    MBEDCRYPTO_LIBRARY
+)