Allow building with -DCRYFS_UPDATE_CHECKS=off, which will create an executable with disabled update checks (the alternative to disable them in the environment also still works).

CMakeLists.txt

@@ -9,7 +9,7 @@ require_clang_version(3.7)
 
 # Default value is not to build test cases
 if(NOT BUILD_TESTING)
-    set(BUILD_TESTING OFF CACHE INTERNAL "BUILD_TESTING")
+    set(BUILD_TESTING OFF CACHE BOOL "BUILD_TESTING")
 endif(NOT BUILD_TESTING)
 
 # Default vaule is to build in release mode
@@ -17,6 +17,11 @@ if(NOT CMAKE_BUILD_TYPE)
     set(CMAKE_BUILD_TYPE Release CACHE INTERNAL "CMAKE_BUILD_TYPE")
 endif(NOT CMAKE_BUILD_TYPE)
 
+# Default value is to do update checks
+if(NOT CRYFS_UPDATE_CHECKS)
+    set(CRYFS_UPDATE_CHECKS ON CACHE BOOL "CRYFS_UPDATE_CHECKS")
+endif(NOT CRYFS_UPDATE_CHECKS)
+
 add_subdirectory(vendor)
 add_subdirectory(src)
 add_subdirectory(test)

ChangeLog.txt

@@ -3,6 +3,9 @@ Version 0.9.6 (unreleased)
 Fixed bugs:
 * Fix potential (although very improbable) deadlock
 
+Improvements:
+* Allow building with -DCRYFS_UPDATE_CHECKS=off, which will create an executable with disabled update checks (the alternative to disable them in the environment also still works).
+
 Compatibility:
 * Compatible with libcurl version >= 7.50.0, and <= 7.21.6 (tested down to 7.19.0)
 * Compatible with Crypto++ 5.6.4

README.md

@@ -92,6 +92,7 @@ Build & Install
 You can pass the following variables to the *cmake* command (using *-Dvariablename=value*):
  - -D**CMAKE_BUILD_TYPE**=[Release|Debug]: Whether to run code optimization or add debug symbols. Default: Release
  - -D**BUILD_TESTING**=[on|off]: Whether to build the test cases (can take a long time). Default: off
+ - -D**CRYFS_UPDATE_CHECKS**=off: Build a CryFS that doesn't check online for updates and security vulnerabilities.
 
 Troubleshooting
 ---------------

src/cryfs-cli/CMakeLists.txt

@@ -15,6 +15,10 @@ target_link_libraries(${PROJECT_NAME} PUBLIC cryfs cpp-utils gitversion)
 target_enable_style_warnings(${PROJECT_NAME})
 target_activate_cpp14(${PROJECT_NAME})
 
+if(NOT CRYFS_UPDATE_CHECKS)
+    target_compile_definitions(${PROJECT_NAME} PRIVATE -DCRYFS_NO_UPDATE_CHECKS)
+endif(NOT CRYFS_UPDATE_CHECKS)
+
 add_executable(${PROJECT_NAME}_bin main.cpp)
 set_target_properties(${PROJECT_NAME}_bin PROPERTIES OUTPUT_NAME cryfs)
 target_link_libraries(${PROJECT_NAME}_bin PUBLIC ${PROJECT_NAME})

src/cryfs-cli/Cli.cpp

@@ -90,11 +90,15 @@ namespace cryfs {
 #ifndef NDEBUG
         cout << "WARNING! This is a debug build. Performance might be slow." << endl;
 #endif
+#ifndef CRYFS_NO_UPDATE_CHECKS
         if (!Environment::noUpdateCheck()) {
             _checkForUpdates();
         } else {
             cout << "Automatic checking for security vulnerabilities and updates is disabled." << endl;
         }
+#else
+# warning Update checks are disabled. The resulting executable will not go online to check for newer versions or known security vulnerabilities.
+#endif
         cout << endl;
     }
 

test/cryfs-cli/CMakeLists.txt

@@ -19,3 +19,4 @@ add_test(${PROJECT_NAME} ${PROJECT_NAME})
 
 target_enable_style_warnings(${PROJECT_NAME})
 target_activate_cpp14(${PROJECT_NAME})
+