[CMake] New compoments MbedTLS and wolfSSL

CMakeLists.txt

@@ -2,11 +2,15 @@
 	Build options:
 	* Standard BUILD_SHARED_LIBS is supported and sets HTTPLIB_SHARED default value.
 	* HTTPLIB_USE_OPENSSL_IF_AVAILABLE (default on)
+	* HTTPLIB_USE_WOLFSSL_IF_AVAILABLE (default off)
+	* HTTPLIB_USE_MBEDTLS_IF_AVAILABLE (default off)
 	* HTTPLIB_USE_ZLIB_IF_AVAILABLE (default on)
 	* HTTPLIB_USE_BROTLI_IF_AVAILABLE (default on)
 	* HTTPLIB_USE_ZSTD_IF_AVAILABLE (default on)
 	* HTTPLIB_BUILD_MODULES (default off)
 	* HTTPLIB_REQUIRE_OPENSSL (default off)
+	* HTTPLIB_REQUIRE_WOLFSSL (default off)
+	* HTTPLIB_REQUIRE_MBEDTLS (default off)
 	* HTTPLIB_REQUIRE_ZLIB (default off)
 	* HTTPLIB_REQUIRE_BROTLI (default off)
 	* HTTPLIB_REQUIRE_ZSTD (default off)
@@ -21,7 +25,7 @@
 
 	-------------------------------------------------------------------------------
 
-	After installation with Cmake, a find_package(httplib COMPONENTS OpenSSL ZLIB Brotli zstd) is available.
+	After installation with Cmake, a find_package(httplib COMPONENTS OpenSSL wolfssl MbedTLS ZLIB Brotli zstd) is available.
 	This creates a httplib::httplib target (if found and if listed components are supported).
 	It can be linked like so:
 
@@ -48,6 +52,8 @@
 	These variables are available after you run find_package(httplib)
 	* HTTPLIB_HEADER_PATH - this is the full path to the installed header (e.g. /usr/include/httplib.h).
 	* HTTPLIB_IS_USING_OPENSSL - a bool for if OpenSSL support is enabled.
+	* HTTPLIB_IS_USING_WOLFSSL - a bool for if wolfSSL support is enabled.
+	* HTTPLIB_IS_USING_MBEDTLS - a bool for if MbedTLS support is enabled.
 	* HTTPLIB_IS_USING_ZLIB - a bool for if ZLIB support is enabled.
 	* HTTPLIB_IS_USING_BROTLI - a bool for if Brotli support is enabled.
 	* HTTPLIB_IS_USING_ZSTD - a bool for if ZSTD support is enabled.
@@ -95,10 +101,14 @@ set(_HTTPLIB_OPENSSL_MIN_VER "3.0.0")
 option(HTTPLIB_NO_EXCEPTIONS "Disable the use of C++ exceptions" OFF)
 # Allow for a build to require OpenSSL to pass, instead of just being optional
 option(HTTPLIB_REQUIRE_OPENSSL "Requires OpenSSL to be found & linked, or fails build." OFF)
+option(HTTPLIB_REQUIRE_WOLFSSL "Requires wolfSSL to be found & linked, or fails build." OFF)
+option(HTTPLIB_REQUIRE_MBEDTLS "Requires MbedTLS to be found & linked, or fails build." OFF)
 option(HTTPLIB_REQUIRE_ZLIB "Requires ZLIB to be found & linked, or fails build." OFF)
 # Allow for a build to casually enable OpenSSL/ZLIB support, but silently continue if not found.
 # Make these options so their automatic use can be specifically disabled (as needed)
 option(HTTPLIB_USE_OPENSSL_IF_AVAILABLE "Uses OpenSSL (if available) to enable HTTPS support." ON)
+option(HTTPLIB_USE_WOLFSSL_IF_AVAILABLE "Uses wolfSSL (if available) to enable HTTPS support." OFF)
+option(HTTPLIB_USE_MBEDTLS_IF_AVAILABLE "Uses MbedTLS (if available) to enable HTTPS support." OFF)
 option(HTTPLIB_USE_ZLIB_IF_AVAILABLE "Uses ZLIB (if available) to enable Zlib compression support." ON)
 # Lets you compile the program as a regular library instead of header-only
 option(HTTPLIB_COMPILE "If ON, uses a Python script to split the header into a compilable header & source file (requires Python v3)." OFF)
@@ -120,6 +130,23 @@ else()
 		message(WARNING "HTTPLIB_BUILD_MODULES requires CMake 3.28 or later. Current version is ${CMAKE_VERSION}. Modules support has been disabled.")
 	endif()
 endif()
+
+# Incompatibility between TLS libraries
+set(TLS_LIBRARIES_USED_TMP 0)
+
+foreach(tls_library OPENSSL WOLFSSL MBEDTLS)
+	set(TLS_REQUIRED ${HTTPLIB_REQUIRE_${tls_library}})
+	set(TLS_IF_AVAILABLE ${HTTPLIB_USE_${tls_library}_IF_AVAILABLE})
+
+	if(TLS_REQUIRED OR TLS_IF_AVAILABLE)
+		math(EXPR TLS_LIBRARIES_USED_TMP "${TLS_LIBRARIES_USED_TMP} + 1")
+	endif()
+endforeach()
+
+if(TLS_LIBRARIES_USED_TMP GREATER 1)
+	message(FATAL_ERROR "TLS libraries are mutually exclusive.")
+endif()
+
 # Defaults to static library but respects standard BUILD_SHARED_LIBS if set
 include(CMakeDependentOption)
 cmake_dependent_option(HTTPLIB_SHARED "Build the library as a shared library instead of static. Has no effect if using header-only."
@@ -139,7 +166,7 @@ endif()
 if(CMAKE_SYSTEM_NAME MATCHES "Windows")
 	if(CMAKE_SYSTEM_VERSION)
 		if(${CMAKE_SYSTEM_VERSION} VERSION_LESS "10.0.0")
-			message(SEND_ERROR "Windows ${CMAKE_SYSTEM_VERSION} or lower is not supported. Please use Windows 10 or later.")
+			message(WARNING "Windows ${CMAKE_SYSTEM_VERSION} or lower is not supported. Please use Windows 10 or later.")
 		endif()
 	else()
 		set(CMAKE_SYSTEM_VERSION "10.0.19041.0")
@@ -176,6 +203,22 @@ elseif(HTTPLIB_USE_OPENSSL_IF_AVAILABLE)
 	endif()
 endif()
 
+if(HTTPLIB_REQUIRE_WOLFSSL)
+	find_package(wolfssl REQUIRED)
+	set(HTTPLIB_IS_USING_WOLFSSL TRUE)
+elseif(HTTPLIB_USE_WOLFSSL_IF_AVAILABLE)
+	find_package(wolfssl QUIET)
+	set(HTTPLIB_IS_USING_WOLFSSL ${wolfssl_FOUND})
+endif()
+
+if(HTTPLIB_REQUIRE_MBEDTLS)
+	find_package(MbedTLS REQUIRED)
+	set(HTTPLIB_IS_USING_MBEDTLS TRUE)
+elseif(HTTPLIB_USE_MBEDTLS_IF_AVAILABLE)
+	find_package(MbedTLS QUIET)
+	set(HTTPLIB_IS_USING_MBEDTLS ${MbedTLS_FOUND})
+endif()
+
 if(HTTPLIB_REQUIRE_ZLIB)
 	find_package(ZLIB REQUIRED)
 	set(HTTPLIB_IS_USING_ZLIB TRUE)
@@ -330,6 +373,8 @@ target_link_libraries(${PROJECT_NAME} ${_INTERFACE_OR_PUBLIC}
 		$<$<BOOL:${HTTPLIB_IS_USING_ZSTD}>:zstd::libzstd>
 		$<$<BOOL:${HTTPLIB_IS_USING_OPENSSL}>:OpenSSL::SSL>
 		$<$<BOOL:${HTTPLIB_IS_USING_OPENSSL}>:OpenSSL::Crypto>
+		$<$<BOOL:${HTTPLIB_IS_USING_WOLFSSL}>:wolfssl::wolfssl>
+		$<$<BOOL:${HTTPLIB_IS_USING_MBEDTLS}>:MbedTLS::mbedtls>
 )
 
 # Set the definitions to enable optional features
@@ -339,6 +384,8 @@ target_compile_definitions(${PROJECT_NAME} ${_INTERFACE_OR_PUBLIC}
 	$<$<BOOL:${HTTPLIB_IS_USING_ZLIB}>:CPPHTTPLIB_ZLIB_SUPPORT>
 	$<$<BOOL:${HTTPLIB_IS_USING_ZSTD}>:CPPHTTPLIB_ZSTD_SUPPORT>
 	$<$<BOOL:${HTTPLIB_IS_USING_OPENSSL}>:CPPHTTPLIB_OPENSSL_SUPPORT>
+	$<$<BOOL:${HTTPLIB_IS_USING_WOLFSSL}>:CPPHTTPLIB_WOLFSSL_SUPPORT>
+	$<$<BOOL:${HTTPLIB_IS_USING_MBEDTLS}>:CPPHTTPLIB_MBEDTLS_SUPPORT>
 	$<$<AND:$<PLATFORM_ID:Darwin>,$<BOOL:${HTTPLIB_DISABLE_MACOSX_AUTOMATIC_ROOT_CERTIFICATES}>>:CPPHTTPLIB_DISABLE_MACOSX_AUTOMATIC_ROOT_CERTIFICATES>
 	$<$<BOOL:${HTTPLIB_USE_NON_BLOCKING_GETADDRINFO}>:CPPHTTPLIB_USE_NON_BLOCKING_GETADDRINFO>
 )

cmake/httplibConfig.cmake.in

@@ -4,6 +4,8 @@
 # Setting these here so they're accessible after install.
 # Might be useful for some users to check which settings were used.
 set(HTTPLIB_IS_USING_OPENSSL @HTTPLIB_IS_USING_OPENSSL@)
+set(HTTPLIB_IS_USING_WOLFSSL @HTTPLIB_IS_USING_WOLFSSL@)
+set(HTTPLIB_IS_USING_MBEDTLS @HTTPLIB_IS_USING_MBEDTLS@)
 set(HTTPLIB_IS_USING_ZLIB @HTTPLIB_IS_USING_ZLIB@)
 set(HTTPLIB_IS_COMPILED @HTTPLIB_COMPILE@)
 set(HTTPLIB_IS_USING_BROTLI @HTTPLIB_IS_USING_BROTLI@)
@@ -25,11 +27,22 @@ if(@HTTPLIB_IS_USING_OPENSSL@)
 	endif()
 	set(httplib_OpenSSL_FOUND ${OpenSSL_FOUND})
 endif()
+
 if(@HTTPLIB_IS_USING_ZLIB@)
 	find_dependency(ZLIB)
 	set(httplib_ZLIB_FOUND ${ZLIB_FOUND})
 endif()
 
+if(@HTTPLIB_IS_USING_WOLFSSL@)
+	find_dependency(wolfssl)
+	set(httplib_wolfssl_FOUND ${wolfssl_FOUND})
+endif()
+
+if(@HTTPLIB_IS_USING_MBEDTLS@)
+	find_dependency(MbedTLS)
+	set(httplib_MbedTLS_FOUND ${MbedTLS_FOUND})
+endif()
+
 if(@HTTPLIB_IS_USING_BROTLI@)
 	# Needed so we can use our own FindBrotli.cmake in this file.
 	# Note that the FindBrotli.cmake file is installed in the same dir as this file.