add cmake install functionality

CMakeLists.txt

@@ -272,3 +272,43 @@ IF (BUILD_FUZZER)
     TARGET_LINK_LIBRARIES(fuzz-client-hello picotls-core picotls-openssl ${OPENSSL_CRYPTO_LIBRARIES} ${AEGIS_LIBRARIES} ${LIB_FUZZER})
 
 ENDIF()
+
+if (NOT CMAKE_INSTALL_INCLUDEDIR)
+    set(CMAKE_INSTALL_INCLUDEDIR ${CMAKE_INSTALL_PREFIX}/include/picotls)
+endif()
+
+install(FILES include/picotls.h DESTINATION ${CMAKE_INSTALL_INCLUDEDIR})
+install(DIRECTORY include/picotls DESTINATION ${CMAKE_INSTALL_INCLUDEDIR})
+
+install(TARGETS picotls-core
+            ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}
+            RUNTIME DESTINATION ${CMAKE_INSTALL_LIBDIR}
+            LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR})
+
+install(TARGETS picotls-minicrypto
+            ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}
+            RUNTIME DESTINATION ${CMAKE_INSTALL_LIBDIR}
+            LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR})
+
+if (TARGET picotls-fusion)
+    install(TARGETS picotls-fusion
+            ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}
+            RUNTIME DESTINATION ${CMAKE_INSTALL_LIBDIR}
+            LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR})
+endif()
+
+if (TARGET picotls-openssl)
+    install(TARGETS picotls-openssl
+            ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}
+            RUNTIME DESTINATION ${CMAKE_INSTALL_LIBDIR}
+            LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR})
+endif()
+
+if (TARGET picotls-mbedtls)
+    install(TARGETS picotls-mbedtls
+            ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}
+            RUNTIME DESTINATION ${CMAKE_INSTALL_LIBDIR}
+            LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR})
+endif()
+
+