Refactored creation of new config files - this happens in a CryConfigLoader now

src/CryConfig.h

@@ -19,11 +19,12 @@ public:
   const std::string &EncryptionKey() const;
   void SetEncryptionKey(const std::string &value);
 
+  void save() const;
+
 private:
   boost::filesystem::path _configfile;
 
   void load();
-  void save() const;
 
   std::string _rootBlob;
   std::string _encKey;

src/CryConfigLoader.cpp

@@ -0,0 +1,51 @@
+#include "CryConfigLoader.h"
+#include <boost/filesystem.hpp>
+
+namespace bf = boost::filesystem;
+using std::unique_ptr;
+using std::make_unique;
+
+namespace cryfs {
+
+unique_ptr<CryConfig> CryConfigLoader::loadOrCreate(const bf::path &filename) {
+  auto config = loadExisting(filename);
+  if (config.get() != nullptr) {
+    return config;
+  }
+  return createNew(filename);
+}
+
+unique_ptr<CryConfig> CryConfigLoader::createNew(const bf::path &filename) {
+  auto config = make_unique<CryConfig>(filename);
+  _initializeConfig(config.get());
+  config->save();
+  return config;
+}
+
+void CryConfigLoader::_initializeConfig(CryConfig *config) {
+  _generateEncKey(config);
+  _generateRootBlobKey(config);
+}
+
+void CryConfigLoader::_generateEncKey(CryConfig *config) {
+  printf("Generating secure encryption key...");
+  fflush(stdout);
+  auto new_key = Cipher::EncryptionKey::CreateOSRandom();
+  config->SetEncryptionKey(new_key.ToString());
+  printf("done\n");
+  fflush(stdout);
+}
+
+void CryConfigLoader::_generateRootBlobKey(CryConfig *config) {
+  //An empty root blob entry will tell CryDevice to create a new root blob
+  config->SetRootBlob("");
+}
+
+unique_ptr<CryConfig> CryConfigLoader::loadExisting(const bf::path &filename) {
+  if (bf::exists(filename)) {
+    return make_unique<CryConfig>(filename);
+  }
+  return nullptr;
+}
+
+}

src/CryConfigLoader.h

@@ -0,0 +1,29 @@
+#pragma once
+#ifndef MESSMER_CRYFS_SRC_CRYCONFIGLOADER_H_
+#define MESSMER_CRYFS_SRC_CRYCONFIGLOADER_H_
+
+#include <memory>
+#include <boost/filesystem/path.hpp>
+#include "CryConfig.h"
+#include <messmer/blockstore/implementations/encrypted/ciphers/AES256_GCM.h>
+
+namespace cryfs {
+
+class CryConfigLoader {
+public:
+  using Cipher = blockstore::encrypted::AES256_GCM;
+
+  static std::unique_ptr<CryConfig> loadOrCreate(const boost::filesystem::path &filename);
+
+  static std::unique_ptr<CryConfig> createNew(const boost::filesystem::path &filename);
+  static std::unique_ptr<CryConfig> loadExisting(const boost::filesystem::path &filename);
+
+private:
+  static void _initializeConfig(CryConfig *config);
+  static void _generateEncKey(CryConfig *config);
+  static void _generateRootBlobKey(CryConfig *config);
+};
+
+}
+
+#endif

src/CryDevice.cpp

@@ -35,7 +35,7 @@ namespace cryfs {
 constexpr uint32_t CryDevice::BLOCKSIZE_BYTES;
 
 CryDevice::CryDevice(unique_ptr<CryConfig> config, unique_ptr<BlockStore> blockStore)
-: _blobStore(make_unique<BlobStoreOnBlocks>(make_unique<CachingBlockStore>(make_unique<EncryptedBlockStore<Cipher>>(std::move(blockStore), GetOrCreateEncryptionKey(config.get()))), BLOCKSIZE_BYTES)), _rootKey(GetOrCreateRootKey(config.get())) {
+: _blobStore(make_unique<BlobStoreOnBlocks>(make_unique<CachingBlockStore>(make_unique<EncryptedBlockStore<Cipher>>(std::move(blockStore), GetEncryptionKey(config.get()))), BLOCKSIZE_BYTES)), _rootKey(GetOrCreateRootKey(config.get())) {
 }
 
 Key CryDevice::GetOrCreateRootKey(CryConfig *config) {
@@ -43,25 +43,15 @@ Key CryDevice::GetOrCreateRootKey(CryConfig *config) {
   if (root_key == "") {
     auto new_key = CreateRootBlobAndReturnKey();
     config->SetRootBlob(new_key.ToString());
+    config->save();
     return new_key;
   }
 
   return Key::FromString(root_key);
 }
 
-CryDevice::Cipher::EncryptionKey CryDevice::GetOrCreateEncryptionKey(CryConfig *config) {
-  string encryption_key = config->EncryptionKey();
-  if (encryption_key == "") {
-    printf("Generating secure encryption key...");
-    fflush(stdout);
-    auto new_key = Cipher::EncryptionKey::CreateOSRandom();
-    printf("done\n");
-    fflush(stdout);
-    config->SetEncryptionKey(new_key.ToString());
-    return new_key;
-  }
-
-  return Cipher::EncryptionKey::FromString(encryption_key);
+CryDevice::Cipher::EncryptionKey CryDevice::GetEncryptionKey(CryConfig *config) {
+  return Cipher::EncryptionKey::FromString(config->EncryptionKey());
 }
 
 Key CryDevice::CreateRootBlobAndReturnKey() {

src/CryDevice.h

@@ -4,10 +4,9 @@
 
 #include <messmer/blockstore/interface/BlockStore.h>
 #include <messmer/blobstore/interface/BlobStore.h>
-#include "CryConfig.h"
+#include "CryConfigLoader.h"
 
 #include <boost/filesystem.hpp>
-#include <messmer/blockstore/implementations/encrypted/ciphers/AES256_GCM.h>
 #include <messmer/fspp/fs_interface/Device.h>
 
 #include "messmer/cpp-utils/macros.h"
@@ -19,7 +18,7 @@ class CryDevice: public fspp::Device {
 public:
   static constexpr uint32_t BLOCKSIZE_BYTES = 32 * 1024;
 
-  using Cipher = blockstore::encrypted::AES256_GCM;
+  using Cipher = CryConfigLoader::Cipher;
 
   CryDevice(std::unique_ptr<CryConfig> config, std::unique_ptr<blockstore::BlockStore> blockStore);
   virtual ~CryDevice();
@@ -36,7 +35,7 @@ public:
 
 private:
   blockstore::Key GetOrCreateRootKey(CryConfig *config);
-  Cipher::EncryptionKey GetOrCreateEncryptionKey(CryConfig *config);
+  Cipher::EncryptionKey GetEncryptionKey(CryConfig *config);
   blockstore::Key CreateRootBlobAndReturnKey();
 
   std::unique_ptr<blobstore::BlobStore> _blobStore;

src/main.cpp

@@ -8,6 +8,7 @@
 #include "messmer/fspp/fuse/Fuse.h"
 #include "messmer/fspp/impl/FilesystemImpl.h"
 #include "CryDevice.h"
+#include "CryConfigLoader.h"
 
 namespace bf = boost::filesystem;
 
@@ -19,7 +20,7 @@ using std::make_unique;
 int main (int argc, char *argv[])
 {
   auto blockStore = make_unique<OnDiskBlockStore>(bf::path("/home/heinzi/cryfstest/root"));
-  auto config = make_unique<cryfs::CryConfig>(bf::path("/home/heinzi/cryfstest/config.json"));
+  auto config = cryfs::CryConfigLoader::loadOrCreate(bf::path("/home/heinzi/cryfstest/config.json"));
   cryfs::CryDevice device(std::move(config), std::move(blockStore));
   fspp::FilesystemImpl fsimpl(&device);
   fspp::fuse::Fuse fuse(&fsimpl);