Use XDG instead of /home/heinzi/.cryfs to store integrity data

src/cpp-utils/system/homedir.cpp

@@ -36,6 +36,15 @@ namespace cpputils {
             return homedir;
         }
 
+        bf::path HomeDirectory::getXDGDataDir() {
+            const char* xdg_data_dir = std::getenv("XDG_DATA_HOME");
+            if (xdg_data_dir != nullptr) {
+                return xdg_data_dir;
+            }
+
+            return cpputils::system::HomeDirectory::get() / ".local" / "share";
+        }
+
         FakeHomeDirectoryRAII::FakeHomeDirectoryRAII(const boost::filesystem::path &fakeHomeDirectory)
                 :_oldHomeDirectory(HomeDirectory::singleton()._home_directory) {
             HomeDirectory::singleton()._home_directory = fakeHomeDirectory;

src/cpp-utils/system/homedir.h

@@ -15,6 +15,8 @@ namespace cpputils {
         public:
             static const boost::filesystem::path &get();
 
+            static boost::filesystem::path getXDGDataDir();
+
         private:
             boost::filesystem::path _home_directory;
 

src/cryfs-cli/Environment.cpp

@@ -22,7 +22,7 @@ namespace cryfs {
     }
 
     const bf::path& Environment::defaultLocalStateDir() {
-        static const bf::path value = cpputils::system::HomeDirectory::get() / ".cryfs";
+        static const bf::path value = cpputils::system::HomeDirectory::getXDGDataDir() / "cryfs";
         return value;
     }