export DLLs functions for MSVC with CMake

- Add 3 DEF files to export functions from Windows DLLs
  - Add gettimeofday to crypto/crypto.def (*1)
  - Remove gai_strerrorA from tls/tls.def (*1)
- Fix CMakeLists.txt to use DEF files as PRIVATE
- Change DLL import library file name since it duplicates with static library
- Ignore compiler warning C4267, and Edit CMAKE_C_FLAGS not to overwrite it (*1)
- Add USE_SHARED option to build openssl.exe with shared libraries (*1)

  (*1) recommended by @mcnameej

tls/CMakeLists.txt

@@ -33,11 +33,14 @@ if (BUILD_SHARED)
 	add_library(tls STATIC $<TARGET_OBJECTS:tls-objects>)
 	add_library(tls-shared SHARED $<TARGET_OBJECTS:tls-objects>)
 	if (WIN32)
+		target_sources(tls-shared PRIVATE
+			${CMAKE_CURRENT_SOURCE_DIR}/tls.def)
 		target_link_libraries(tls-shared ssl-shared crypto-shared Ws2_32.lib)
 		set(TLS_POSTFIX -${TLS_MAJOR_VERSION})
 	endif()
 	set_target_properties(tls-shared PROPERTIES
-		OUTPUT_NAME tls${TLS_POSTFIX} ARCHIVE_OUTPUT_NAME tls)
+		OUTPUT_NAME tls${TLS_POSTFIX}
+		ARCHIVE_OUTPUT_NAME tls${TLS_POSTFIX})
 	set_target_properties(tls-shared PROPERTIES VERSION ${TLS_VERSION}
 		SOVERSION ${TLS_MAJOR_VERSION})
 	install(TARGETS tls tls-shared DESTINATION lib)

tls/Makefile.am

@@ -4,6 +4,7 @@ lib_LTLIBRARIES = libtls.la
 
 EXTRA_DIST = VERSION
 EXTRA_DIST += CMakeLists.txt
+EXTRA_DIST += tls.def
 
 libtls_la_LDFLAGS = -version-info @LIBTLS_VERSION@ -no-undefined
 libtls_la_LIBADD = $(abs_top_builddir)/ssl/libssl.la

tls/tls.def

@@ -0,0 +1,86 @@
+EXPORTS
+strsep
+tls_accept_cbs
+tls_accept_fds
+tls_accept_socket
+tls_check_name
+tls_client
+tls_close
+tls_config_add_keypair_file
+tls_config_add_keypair_mem
+tls_config_clear_keys
+tls_config_error
+tls_config_free
+tls_config_insecure_noverifycert
+tls_config_insecure_noverifyname
+tls_config_insecure_noverifytime
+tls_config_load_file
+tls_config_new
+tls_config_parse_protocols
+tls_config_prefer_ciphers_client
+tls_config_prefer_ciphers_server
+tls_config_set_alpn
+tls_config_set_ca_file
+tls_config_set_ca_mem
+tls_config_set_ca_path
+tls_config_set_cert_file
+tls_config_set_cert_mem
+tls_config_set_ciphers
+tls_config_set_dheparams
+tls_config_set_ecdhecurve
+tls_config_set_error
+tls_config_set_errorx
+tls_config_set_key_file
+tls_config_set_key_mem
+tls_config_set_keypair_file
+tls_config_set_keypair_mem
+tls_config_set_protocols
+tls_config_set_verify_depth
+tls_config_verify
+tls_config_verify_client
+tls_config_verify_client_optional
+tls_configure
+tls_configure_server
+tls_configure_ssl
+tls_configure_ssl_keypair
+tls_configure_ssl_verify
+tls_conn_alpn_selected
+tls_conn_cipher
+tls_conn_servername
+tls_conn_version
+tls_connect
+tls_connect_cbs
+tls_connect_fds
+tls_connect_servername
+tls_connect_socket
+tls_conninfo_free
+tls_conninfo_populate
+tls_error
+tls_error_set
+tls_error_setx
+tls_free
+tls_handshake
+tls_handshake_client
+tls_handshake_server
+tls_host_port
+tls_init
+tls_load_file
+tls_new
+tls_peer_cert_contains_name
+tls_peer_cert_hash
+tls_peer_cert_issuer
+tls_peer_cert_notafter
+tls_peer_cert_notbefore
+tls_peer_cert_provided
+tls_peer_cert_subject
+tls_read
+tls_reset
+tls_server
+tls_server_conn
+tls_set_cbs
+tls_set_error
+tls_set_errorx
+tls_sni_ctx_free
+tls_sni_ctx_new
+tls_ssl_error
+tls_write