CryFS stores root blob key in config file!

src/cryfs_lib/CMakeLists.txt

@@ -1,3 +1,3 @@
-add_library(cryfs_lib CryDevice.cpp CryDir.cpp CryFile.cpp CryNode.cpp CryOpenFile.cpp impl/DirBlob.cpp)
+add_library(cryfs_lib CryDevice.cpp CryDir.cpp CryFile.cpp CryNode.cpp CryOpenFile.cpp CryConfig.cpp impl/DirBlob.cpp)
 
 target_link_libraries(cryfs_lib)

src/cryfs_lib/CryConfig.cpp

@@ -0,0 +1,47 @@
+#include <cryfs_lib/CryConfig.h>
+
+#include <boost/filesystem.hpp>
+#include <boost/property_tree/ptree.hpp>
+#include <boost/property_tree/json_parser.hpp>
+
+namespace bf = boost::filesystem;
+
+using boost::property_tree::ptree;
+
+namespace cryfs {
+
+CryConfig::CryConfig(const bf::path &configfile)
+:_configfile(configfile), _root_blob("") {
+  if (bf::exists(_configfile)) {
+    load();
+  }
+}
+
+void CryConfig::load() {
+  ptree pt;
+  read_json(_configfile.native(), pt);
+
+  _root_blob = pt.get("cryfs.rootblob", "");
+}
+
+void CryConfig::save() const {
+  ptree pt;
+
+  pt.put("cryfs.rootblob", _root_blob);
+
+  write_json(_configfile.native(), pt);
+}
+
+const std::string &CryConfig::RootBlob() const {
+  return _root_blob;
+}
+
+void CryConfig::SetRootBlob(const std::string &value) {
+  _root_blob = value;
+}
+
+CryConfig::~CryConfig() {
+  save();
+}
+
+}

src/cryfs_lib/CryConfig.h

@@ -0,0 +1,29 @@
+#pragma once
+#ifndef CRYFS_LIB_CRYCONFIG_H_
+#define CRYFS_LIB_CRYCONFIG_H_
+
+#include <boost/filesystem/path.hpp>
+
+namespace cryfs {
+
+class CryConfig {
+public:
+  CryConfig(const boost::filesystem::path &configfile);
+  virtual ~CryConfig();
+
+  const std::string &RootBlob() const;
+  void SetRootBlob(const std::string &value);
+
+private:
+  boost::filesystem::path _configfile;
+
+  void load();
+  void save() const;
+
+  std::string _root_blob;
+
+};
+
+}
+
+#endif

src/cryfs_lib/CryDevice.cpp

@@ -20,12 +20,19 @@ using blobstore::BlobStore;
 
 namespace cryfs {
 
-CryDevice::CryDevice(unique_ptr<BlobStore> blobStore)
-: _blob_store(std::move(blobStore)), _root_key() {
+CryDevice::CryDevice(unique_ptr<CryConfig> config, unique_ptr<BlobStore> blobStore)
+: _blob_store(std::move(blobStore)), _root_key(config->RootBlob()) {
+  if (_root_key == "") {
+    _root_key = CreateRootBlobAndReturnKey();
+    config->SetRootBlob(_root_key);
+  }
+}
+
+string CryDevice::CreateRootBlobAndReturnKey() {
   auto rootBlob = _blob_store->create(DIR_BLOBSIZE);
   DirBlob rootDir(std::move(rootBlob.blob));
   rootDir.InitializeEmptyDir();
-  _root_key = rootBlob.key;
+  return rootBlob.key;
 }
 
 CryDevice::~CryDevice() {

src/cryfs_lib/CryDevice.h

@@ -2,6 +2,8 @@
 #ifndef CRYFS_LIB_CRYDEVICE_H_
 #define CRYFS_LIB_CRYDEVICE_H_
 
+#include "CryConfig.h"
+
 #include <boost/filesystem.hpp>
 #include <fspp/fs_interface/Device.h>
 
@@ -17,7 +19,7 @@ class CryDevice: public fspp::Device {
 public:
   static constexpr size_t DIR_BLOBSIZE = 4096;
 
-  CryDevice(std::unique_ptr<blobstore::BlobStore> blobStore);
+  CryDevice(std::unique_ptr<CryConfig> config, std::unique_ptr<blobstore::BlobStore> blobStore);
   virtual ~CryDevice();
 
   void statfs(const boost::filesystem::path &path, struct ::statvfs *fsstat) override;
@@ -25,12 +27,11 @@ public:
   blobstore::BlobWithKey CreateBlob(size_t size);
 
 private:
+  std::string CreateRootBlobAndReturnKey();
   std::unique_ptr<fspp::Node> Load(const bf::path &path) override;
 
   std::unique_ptr<blobstore::BlobStore> _blob_store;
 
-  //TODO This takes a new root key each run, the filesystem won't survive restarting the daemon...
-  //     Find a way so that the next run will recognize the created root element.
   std::string _root_key;
 
   DISALLOW_COPY_AND_ASSIGN(CryDevice);

src/main.cpp

@@ -19,7 +19,8 @@ int main (int argc, char *argv[])
 {
   printf("Version: %d\n", buildconfig::VERSION::MAJOR);
   auto blobStore = make_unique<OnDiskBlobStore>(bf::path("/home/heinzi/cryfstest/root"));
-  cryfs::CryDevice device(std::move(blobStore));
+  auto config = make_unique<cryfs::CryConfig>(bf::path("/home/heinzi/cryfstest/config.json"));
+  cryfs::CryDevice device(std::move(config), std::move(blobStore));
   fspp::FilesystemImpl fsimpl(&device);
   fspp::fuse::Fuse fuse(&fsimpl);
   fuse.run(argc, argv);