Refactor config file handling

src/config/CryConfig.cpp

@@ -8,33 +8,36 @@ namespace bf = boost::filesystem;
 
 using boost::property_tree::ptree;
 using std::string;
+using std::istream;
+using std::ostream;
 
 namespace cryfs {
 
-CryConfig::CryConfig(const bf::path &configfile)
+CryConfig::CryConfig()
-:_configfile(configfile), _rootBlob(""), _encKey(""), _cipher("") {
+: _rootBlob(""), _encKey(""), _cipher("") {
-  if (bf::exists(_configfile)) {
-    load();
-  }
 }
 
-void CryConfig::load() {
+CryConfig::CryConfig(CryConfig &&rhs)
+: _rootBlob(std::move(rhs._rootBlob)), _encKey(std::move(rhs._encKey)), _cipher(std::move(rhs._cipher)) {
+}
+
+void CryConfig::load(istream &loadSource) {
   ptree pt;
-  read_json(_configfile.native(), pt);
+  read_json(loadSource, pt);
 
   _rootBlob = pt.get("cryfs.rootblob", "");
   _encKey = pt.get("cryfs.key", "");
   _cipher = pt.get("cryfs.cipher", "");
 }
 
-void CryConfig::save() const {
+void CryConfig::save(ostream &writeDestination) const {
   ptree pt;
 
   pt.put("cryfs.rootblob", _rootBlob);
   pt.put("cryfs.key", _encKey);
   pt.put("cryfs.cipher", _cipher);
 
-  write_json(_configfile.native(), pt);
+  write_json(writeDestination, pt);
 }
 
 const std::string &CryConfig::RootBlob() const {
@@ -61,8 +64,4 @@ void CryConfig::SetCipher(const std::string &value) {
   _cipher = value;
 }
 
-CryConfig::~CryConfig() {
-  save();
-}
-
 }

src/config/CryConfig.h

@@ -5,13 +5,14 @@
 #include <boost/filesystem/path.hpp>
 
 #include "messmer/cpp-utils/macros.h"
+#include <iostream>
 
 namespace cryfs {
 
-class CryConfig {
+class CryConfig final {
 public:
-  explicit CryConfig(const boost::filesystem::path &configfile);
+  CryConfig();
-  virtual ~CryConfig();
+  CryConfig(CryConfig &&rhs);
 
   const std::string &RootBlob() const;
   void SetRootBlob(const std::string &value);
@@ -22,13 +23,10 @@ public:
   const std::string &Cipher() const;
   void SetCipher(const std::string &value);
 
-  void save() const;
+  void load(std::istream &loadSource);
+  void save(std::ostream &destination) const;
 
 private:
-  boost::filesystem::path _configfile;
-
-  void load();
-
   std::string _rootBlob;
   std::string _encKey;
   std::string _cipher;

src/config/CryConfigCreator.cpp

@@ -0,0 +1,72 @@
+#include "CryConfigCreator.h"
+#include "CryCipher.h"
+#include <messmer/blockstore/implementations/encrypted/ciphers/ciphers.h>
+
+using cpputils::Console;
+using cpputils::unique_ref;
+using std::string;
+using std::vector;
+
+namespace cryfs {
+
+    CryConfigCreator::CryConfigCreator(unique_ref<Console> console)
+        :_console(std::move(console)) {
+    }
+
+    CryConfig CryConfigCreator::create() {
+        CryConfig config;
+        config.SetCipher(_generateCipher());
+        config.SetEncryptionKey(_generateEncKey(config.Cipher()));
+        config.SetRootBlob(_generateRootBlobKey());
+        return config;
+    }
+
+    CryConfig CryConfigCreator::createForTest() {
+        CryConfig config;
+        config.SetCipher(_generateCipherForTest());
+        config.SetEncryptionKey(_generateEncKeyForTest(config.Cipher()));
+        config.SetRootBlob(_generateRootBlobKey());
+        return config;
+    }
+
+    string CryConfigCreator::_generateCipher() {
+        vector<string> ciphers = CryCiphers::supportedCipherNames();
+        string cipherName = "";
+        bool askAgain = true;
+        while(askAgain) {
+            int cipherIndex = _console->ask("Which block cipher do you want to use?", ciphers);
+            cipherName = ciphers[cipherIndex];
+            askAgain = !_showWarningForCipherAndReturnIfOk(cipherName);
+        };
+        return cipherName;
+    }
+
+    bool CryConfigCreator::_showWarningForCipherAndReturnIfOk(const string &cipherName) {
+        auto warning = CryCiphers::find(cipherName).warning();
+        if (warning == boost::none) {
+            return true;
+        }
+        return _console->askYesNo(string() + (*warning) + " Do you want to take this cipher nevertheless?");
+    }
+
+    string CryConfigCreator::_generateEncKey(const std::string &cipher) {
+        _console->print("\nGenerating secure encryption key...");
+        auto key = CryCiphers::find(cipher).createKey();
+        _console->print("done\n");
+        return key;
+    }
+
+    string CryConfigCreator::_generateCipherForTest() {
+        return "aes-256-gcm";
+    }
+
+    string CryConfigCreator::_generateEncKeyForTest(const std::string &) {
+        return blockstore::encrypted::AES256_GCM::EncryptionKey::CreatePseudoRandom().ToString();
+    }
+
+    string CryConfigCreator::_generateRootBlobKey() {
+        //An empty root blob entry will tell CryDevice to create a new root blob
+        return "";
+    }
+
+}

src/config/CryConfigCreator.h

@@ -0,0 +1,31 @@
+#ifndef CRYFS_SRC_CONFIG_CRYCONFIGCREATOR_H
+#define CRYFS_SRC_CONFIG_CRYCONFIGCREATOR_H
+
+#include <messmer/cpp-utils/pointer/unique_ref.h>
+#include <messmer/cpp-utils/io/Console.h>
+#include "CryConfig.h"
+
+namespace cryfs {
+    class CryConfigCreator final {
+    public:
+        CryConfigCreator(cpputils::unique_ref<cpputils::Console> console);
+
+        CryConfig create();
+        CryConfig createForTest();
+    private:
+        std::string _generateCipher();
+        std::string _generateEncKey(const std::string &cipher);
+        std::string _generateRootBlobKey();
+        bool _showWarningForCipherAndReturnIfOk(const std::string &cipherName);
+
+        //TODO Don't have these functions here, but use a CryConfigCreator interface and mock it in the tests
+        std::string _generateEncKeyForTest(const std::string &cipher);
+        std::string _generateCipherForTest();
+
+        cpputils::unique_ref<cpputils::Console> _console;
+
+        DISALLOW_COPY_AND_ASSIGN(CryConfigCreator);
+    };
+}
+
+#endif

src/config/CryConfigFile.cpp

@@ -0,0 +1,44 @@
+#include "CryConfigFile.h"
+#include <fstream>
+#include <boost/filesystem.hpp>
+
+using boost::optional;
+using boost::none;
+using std::ifstream;
+using std::ofstream;
+namespace bf = boost::filesystem;
+
+namespace cryfs {
+
+CryConfigFile CryConfigFile::create(const bf::path &path, CryConfig config) {
+    return CryConfigFile(path, std::move(config));
+}
+
+optional<CryConfigFile> CryConfigFile::load(const bf::path &path) {
+    if (!bf::exists(path)) {
+        return none;
+    }
+    ifstream file(path.native());
+    CryConfig config;
+    config.load(file);
+    return CryConfigFile(path, std::move(config));
+}
+
+CryConfigFile::CryConfigFile(const bf::path &path, CryConfig config)
+    : _path (path), _config(std::move(config)) {
+}
+
+CryConfigFile::CryConfigFile(CryConfigFile &&rhs)
+    : _path(std::move(rhs._path)), _config(std::move(rhs._config)) {
+}
+
+void CryConfigFile::save() const {
+    ofstream file(_path.native(), ofstream::out|ofstream::binary|ofstream::trunc);
+    _config.save(file);
+}
+
+CryConfig *CryConfigFile::config() {
+    return &_config;
+}
+
+}

src/config/CryConfigFile.h

@@ -0,0 +1,29 @@
+#ifndef CRYFS_SRC_CONFIG_CRYCONFIGFILE_H
+#define CRYFS_SRC_CONFIG_CRYCONFIGFILE_H
+
+#include <boost/optional.hpp>
+#include <boost/filesystem/path.hpp>
+#include "CryConfig.h"
+
+namespace cryfs {
+    class CryConfigFile final {
+    public:
+        CryConfigFile(CryConfigFile &&rhs);
+
+        static CryConfigFile create(const boost::filesystem::path &path, CryConfig config);
+        static boost::optional<CryConfigFile> load(const boost::filesystem::path &path);
+        void save() const;
+
+        CryConfig *config();
+
+    private:
+        CryConfigFile(const boost::filesystem::path &path, CryConfig config);
+
+        boost::filesystem::path _path;
+        CryConfig _config;
+
+        DISALLOW_COPY_AND_ASSIGN(CryConfigFile);
+    };
+}
+
+#endif

src/config/CryConfigLoader.cpp

@@ -1,4 +1,5 @@
 #include "CryConfigLoader.h"
+#include "CryConfigFile.h"
 #include <boost/filesystem.hpp>
 
 namespace bf = boost::filesystem;
@@ -15,95 +16,36 @@ namespace cryfs {
 
 CryConfigLoader::CryConfigLoader(): CryConfigLoader(make_unique_ref<IOStreamConsole>()) {}
 
-CryConfigLoader::CryConfigLoader(unique_ref<Console> console) : _console(std::move(console)) {}
+CryConfigLoader::CryConfigLoader(unique_ref<Console> console) : _creator(std::move(console)) {}
 
-unique_ref<CryConfig> CryConfigLoader::loadOrCreate(const bf::path &filename) {
+CryConfigFile CryConfigLoader::loadOrCreate(const bf::path &filename) {
-  auto config = loadExisting(filename);
+  auto config = CryConfigFile::load(filename);
   if (config != none) {
     return std::move(*config);
   }
   return createNew(filename);
 }
 
-unique_ref<CryConfig> CryConfigLoader::createNew(const bf::path &filename) {
+CryConfigFile CryConfigLoader::createNew(const bf::path &filename) {
-  auto config = make_unique_ref<CryConfig>(filename);
+  auto config = _creator.create();
-  _initializeConfig(config.get());
+  auto configFile = CryConfigFile::create(filename, std::move(config));
-  config->save();
+  configFile.save();
-  return config;
+  return configFile;
 }
 
-void CryConfigLoader::_initializeConfig(CryConfig *config) {
+CryConfigFile CryConfigLoader::loadOrCreateForTest(const bf::path &filename) {
-  _generateCipher(config);
+  auto config = CryConfigFile::load(filename);
-  _generateEncKey(config);
-  _generateRootBlobKey(config);
-}
-
-void CryConfigLoader::_initializeConfigWithWeakKey(CryConfig *config) {
-  _generateTestCipher(config);
-  _generateWeakEncKey(config);
-  _generateRootBlobKey(config);
-}
-
-void CryConfigLoader::_generateCipher(CryConfig *config) {
-  vector<string> ciphers = CryCiphers::supportedCipherNames();
-  string cipherName = "";
-  bool askAgain = true;
-  while(askAgain) {
-    int cipherIndex = _console->ask("Which block cipher do you want to use?", ciphers);
-    cipherName = ciphers[cipherIndex];
-    askAgain = !_showWarningForCipherAndReturnIfOk(cipherName);
-  };
-  config->SetCipher(cipherName);
-}
-
-bool CryConfigLoader::_showWarningForCipherAndReturnIfOk(const string &cipherName) {
-  auto warning = CryCiphers::find(cipherName).warning();
-  if (warning == boost::none) {
-    return true;
-  }
-  return _console->askYesNo(string() + (*warning) + " Do you want to take this cipher nevertheless?");
-}
-
-void CryConfigLoader::_generateEncKey(CryConfig *config) {
-  _console->print("\nGenerating secure encryption key...");
-  config->SetEncryptionKey(CryCiphers::find(config->Cipher()).createKey());
-  _console->print("done\n");
-}
-
-void CryConfigLoader::_generateTestCipher(CryConfig *config) {
-  config->SetCipher("aes-256-gcm");
-}
-
-void CryConfigLoader::_generateWeakEncKey(CryConfig *config) {
-  auto new_key = blockstore::encrypted::AES256_GCM::EncryptionKey::CreatePseudoRandom();
-  config->SetEncryptionKey(new_key.ToString());
-}
-
-void CryConfigLoader::_generateRootBlobKey(CryConfig *config) {
-  //An empty root blob entry will tell CryDevice to create a new root blob
-  config->SetRootBlob("");
-}
-
-optional<unique_ref<CryConfig>> CryConfigLoader::loadExisting(const bf::path &filename) {
-  if (bf::exists(filename)) {
-    return make_unique_ref<CryConfig>(filename);
-  }
-  return none;
-}
-
-unique_ref<CryConfig> CryConfigLoader::loadOrCreateWithWeakKey(const bf::path &filename) {
-  auto config = loadExisting(filename);
   if (config != none) {
     return std::move(*config);
   }
-  return createNewWithWeakKey(filename);
+  return createNewForTest(filename);
 }
 
-unique_ref<CryConfig> CryConfigLoader::createNewWithWeakKey(const bf::path &filename) {
+CryConfigFile CryConfigLoader::createNewForTest(const bf::path &filename) {
-  auto config = make_unique_ref<CryConfig>(filename);
+  auto config = _creator.createForTest();
-  _initializeConfigWithWeakKey(config.get());
+  auto configFile = CryConfigFile::create(filename, std::move(config));
-  config->save();
+  configFile.save();
-  return config;
+  return configFile;
 }
 
 }

src/config/CryConfigLoader.h

@@ -4,10 +4,9 @@
 
 #include <messmer/cpp-utils/pointer/unique_ref.h>
 #include <boost/filesystem/path.hpp>
-#include "CryConfig.h"
+#include "CryConfigFile.h"
 #include "CryCipher.h"
-#include <messmer/blockstore/implementations/encrypted/ciphers/ciphers.h>
+#include "CryConfigCreator.h"
-#include <messmer/cpp-utils/io/Console.h>
 
 namespace cryfs {
 
@@ -16,28 +15,15 @@ public:
   CryConfigLoader();
   explicit CryConfigLoader(cpputils::unique_ref<cpputils::Console> console);
 
-  cpputils::unique_ref<CryConfig> loadOrCreate(const boost::filesystem::path &filename);
+  CryConfigFile loadOrCreate(const boost::filesystem::path &filename);
+  CryConfigFile createNew(const boost::filesystem::path &filename);
 
-  cpputils::unique_ref<CryConfig> createNew(const boost::filesystem::path &filename);
+  //This methods are only for testing purposes, because creating weak keys is much faster than creating strong keys.
-  boost::optional<cpputils::unique_ref<CryConfig>> loadExisting(const boost::filesystem::path &filename);
+  CryConfigFile loadOrCreateForTest(const boost::filesystem::path &filename);
-
+  CryConfigFile createNewForTest(const boost::filesystem::path &filename);
-  //This method is only for testing purposes, because creating weak keys is much faster than creating strong keys.
-  cpputils::unique_ref<CryConfig> loadOrCreateWithWeakKey(const boost::filesystem::path &filename);
-  cpputils::unique_ref<CryConfig> createNewWithWeakKey(const boost::filesystem::path &filename);
 
 private:
-  void _initializeConfig(CryConfig *config);
+  CryConfigCreator _creator;
-  void _generateCipher(CryConfig *config);
-  void _generateEncKey(CryConfig *config);
-  void _generateRootBlobKey(CryConfig *config);
-
-  void _initializeConfigWithWeakKey(CryConfig *config);  // TODO Rename to _initializeConfigForTest
-  void _generateWeakEncKey(CryConfig *config); // TODO Rename to _generateTestEncKey
-  void _generateTestCipher(CryConfig *config);
-
-  bool _showWarningForCipherAndReturnIfOk(const std::string &cipherName);
-
-  cpputils::unique_ref<cpputils::Console> _console;
 };
 
 }

src/filesystem/CryDevice.cpp

@@ -46,27 +46,24 @@ namespace cryfs {
 
 constexpr uint32_t CryDevice::BLOCKSIZE_BYTES;
 
-CryDevice::CryDevice(unique_ref<CryConfig> config, unique_ref<BlockStore> blockStore)
+CryDevice::CryDevice(CryConfigFile configFile, unique_ref<BlockStore> blockStore)
 : _fsBlobStore(
       make_unique_ref<ParallelAccessFsBlobStore>(
         make_unique_ref<CachingFsBlobStore>(
           make_unique_ref<FsBlobStore>(
             make_unique_ref<BlobStoreOnBlocks>(
               make_unique_ref<CachingBlockStore>(
-                CreateEncryptedBlockStore(*config, std::move(blockStore))
+                CreateEncryptedBlockStore(*configFile.config(), std::move(blockStore))
               ), BLOCKSIZE_BYTES)))
         )
       ),
-  _rootKey(GetOrCreateRootKey(config.get())) {
+  _rootKey(GetOrCreateRootKey(&configFile)) {
 }
 
 Key CryDevice::CreateRootBlobAndReturnKey() {
   return _fsBlobStore->createDirBlob()->key();
 }
 
-CryDevice::~CryDevice() {
-}
-
 optional<unique_ref<fspp::Node>> CryDevice::Load(const bf::path &path) {
   ASSERT(path.is_absolute(), "Non absolute path given");
 
@@ -149,12 +146,12 @@ void CryDevice::RemoveBlob(const blockstore::Key &key) {
   _fsBlobStore->remove(std::move(*blob));
 }
 
-Key CryDevice::GetOrCreateRootKey(CryConfig *config) {
+Key CryDevice::GetOrCreateRootKey(CryConfigFile *configFile) {
-  string root_key = config->RootBlob();
+  string root_key = configFile->config()->RootBlob();
   if (root_key == "") {
     auto new_key = CreateRootBlobAndReturnKey();
-    config->SetRootBlob(new_key.ToString());
+    configFile->config()->SetRootBlob(new_key.ToString());
-    config->save();
+    configFile->save();
     return new_key;
   }
 

src/filesystem/CryDevice.h

@@ -15,12 +15,11 @@
 
 namespace cryfs {
 
-class CryDevice: public fspp::Device {
+class CryDevice final: public fspp::Device {
 public:
   static constexpr uint32_t BLOCKSIZE_BYTES = 32 * 1024;
 
-  CryDevice(cpputils::unique_ref<CryConfig> config, cpputils::unique_ref<blockstore::BlockStore> blockStore);
+  CryDevice(CryConfigFile config, cpputils::unique_ref<blockstore::BlockStore> blockStore);
-  virtual ~CryDevice();
 
   void statfs(const boost::filesystem::path &path, struct ::statvfs *fsstat) override;
 
@@ -41,7 +40,7 @@ private:
 
   blockstore::Key _rootKey;
 
-  blockstore::Key GetOrCreateRootKey(CryConfig *config);
+  blockstore::Key GetOrCreateRootKey(CryConfigFile *config);
   blockstore::Key CreateRootBlobAndReturnKey();
   static cpputils::unique_ref<blockstore::BlockStore> CreateEncryptedBlockStore(const CryConfig &config, cpputils::unique_ref<blockstore::BlockStore> baseBlockStore);