add cmake Find/Use for system libraries

cmake/FindSSH2.cmake

@@ -0,0 +1,30 @@
+# - Try to find the ssh2 libssh2 library
+# Once done this will define
+#
+#  SSH2_FOUND - system has the SSH2 libssh2 library
+#  SSH2_INCLUDE_DIR - the SSH2 libssh2 include directory
+#  SSH2_LIBRARIES - The libraries needed to use SSH2 libssh2
+
+# only look in default directories
+find_path(
+	SSH2_INCLUDE_DIR
+	NAMES libssh2.h
+	DOC "ssh2 include dir"
+)
+
+find_library(
+	SSH2_LIBRARY
+	NAMES ssh2 libssh2
+	DOC "ssh2 library"
+)
+
+set(SSH2_INCLUDE_DIRS ${SSH2_INCLUDE_DIR})
+set(SSH2_LIBRARIES ${SSH2_LIBRARY})
+
+# handle the QUIETLY and REQUIRED arguments and set CURL_FOUND to TRUE
+# if all listed variables are TRUE, hide their existence from configuration view
+include(FindPackageHandleStandardArgs)
+find_package_handle_standard_args(SSH2 DEFAULT_MSG
+	SSH2_LIBRARY SSH2_INCLUDE_DIR)
+mark_as_advanced (SSH2_INCLUDE_DIR SSH2_LIBRARY)
+

cmake/UseOpenSSL.cmake

@@ -0,0 +1,14 @@
+function(eth_apply TARGET REQUIRED)
+	find_package (OpenSSL)
+
+	# cmake supplied FindOpenSSL doesn't set all our variables
+	set(OPENSSL_INCLUDE_DIRS ${OPENSSL_INCLUDE_DIR})
+
+	eth_show_dependency(OPENSSL OpenSSL)
+	if (OPENSSL_FOUND)
+		target_include_directories(${TARGET} SYSTEM PUBLIC ${OPENSSL_INCLUDE_DIRS})
+		target_link_libraries(${TARGET} ${OPENSSL_LIBRARIES})
+	elseif (NOT ${REQUIRED} STREQUAL "OPTIONAL")
+		message(FATAL_ERROR "OpenSSL library not found")
+	endif()
+endfunction()

cmake/UseSSH2.cmake

@@ -0,0 +1,11 @@
+function(eth_apply TARGET REQUIRED)
+	find_package (SSH2)
+	eth_show_dependency(SSH2 ssh2)
+
+	if (SSH2_FOUND)
+		target_include_directories(${TARGET} SYSTEM PUBLIC ${SSH2_INCLUDE_DIRS})
+		target_link_libraries(${TARGET} ${SSH2_LIBRARIES})
+	elseif (NOT ${REQUIRED} STREQUAL "OPTIONAL")
+		message(FATAL_ERROR "ssh2 library not found")
+	endif()
+endfunction()

cmake/UseZLIB.cmake

@@ -0,0 +1,11 @@
+function(eth_apply TARGET REQUIRED)
+	find_package (ZLIB)
+	eth_show_dependency(ZLIB Zlib)
+	if (ZLIB_FOUND)
+		target_include_directories(${TARGET} SYSTEM PUBLIC ${ZLIB_INCLUDE_DIRS})
+		# target_link_libraries(${TARGET} ${ZLIB_LIBRARIES})
+		target_link_libraries(${TARGET} z)
+	elseif (NOT ${REQUIRED} STREQUAL "OPTIONAL")
+		message(FATAL_ERROR "Zlib library not found")
+	endif()
+endfunction()