From 83fad1ca53b4a354298bd0b9ef90ad074de53d69 Mon Sep 17 00:00:00 2001
From: Sebastian Messmer <mail@smessmer.de>
Date: Tue, 9 Dec 2014 20:36:32 +0100
Subject: [PATCH] Create dedicated Key class for addressing blocks

---
 src/cryfs_lib/CryDevice.cpp     | 22 +++++++++++++++-------
 src/cryfs_lib/CryDevice.h       |  7 ++++---
 src/cryfs_lib/impl/DirBlock.cpp | 13 ++++++++-----
 src/cryfs_lib/impl/DirBlock.h   |  5 +++--
 4 files changed, 30 insertions(+), 17 deletions(-)

diff --git a/src/cryfs_lib/CryDevice.cpp b/src/cryfs_lib/CryDevice.cpp
index b7a7efae..9cbe2ee7 100644
--- a/src/cryfs_lib/CryDevice.cpp
+++ b/src/cryfs_lib/CryDevice.cpp
@@ -17,18 +17,26 @@ using fspp::fuse::CHECK_RETVAL;
 using fspp::fuse::FuseErrnoException;
 
 using blockstore::BlockStore;
+using blockstore::Key;
 
 namespace cryfs {
 
 CryDevice::CryDevice(unique_ptr<CryConfig> config, unique_ptr<BlockStore> blockStore)
-: _block_store(std::move(blockStore)), _root_key(config->RootBlock()) {
-  if (_root_key == "") {
-    _root_key = CreateRootBlockAndReturnKey();
-    config->SetRootBlock(_root_key);
-  }
+: _block_store(std::move(blockStore)), _root_key(GetOrCreateRootKey(config.get())) {
 }
 
-string CryDevice::CreateRootBlockAndReturnKey() {
+Key CryDevice::GetOrCreateRootKey(CryConfig *config) {
+  string root_key = config->RootBlock();
+  if (root_key == "") {
+    auto key = CreateRootBlockAndReturnKey();
+    config->SetRootBlock(key.AsString());
+    return key;
+  }
+
+  return Key::FromString(root_key);
+}
+
+Key CryDevice::CreateRootBlockAndReturnKey() {
   auto rootBlock = _block_store->create(DIR_BLOCKSIZE);
   DirBlock rootDir(std::move(rootBlock.block));
   rootDir.InitializeEmptyDir();
@@ -50,7 +58,7 @@ unique_ptr<fspp::Node> CryDevice::Load(const bf::path &path) {
     }
     unique_ptr<DirBlock> currentDir = make_unique<DirBlock>(std::move(current_block));
 
-    string childKey = currentDir->GetBlockKeyForName(component.c_str());
+    Key childKey = currentDir->GetBlockKeyForName(component.c_str());
     current_block = _block_store->load(childKey);
   }
   if (DirBlock::IsDir(*current_block)) {
diff --git a/src/cryfs_lib/CryDevice.h b/src/cryfs_lib/CryDevice.h
index 9d241d77..a20e4637 100644
--- a/src/cryfs_lib/CryDevice.h
+++ b/src/cryfs_lib/CryDevice.h
@@ -18,7 +18,7 @@ class CryDevice: public fspp::Device {
 public:
   static constexpr size_t DIR_BLOCKSIZE = 4096;
 
-  CryDevice(std::unique_ptr<CryConfig> config, std::unique_ptr<blockstore::BlockStore> blockbStore);
+  CryDevice(std::unique_ptr<CryConfig> config, std::unique_ptr<blockstore::BlockStore> blockStore);
   virtual ~CryDevice();
 
   void statfs(const boost::filesystem::path &path, struct ::statvfs *fsstat) override;
@@ -26,12 +26,13 @@ public:
   blockstore::BlockWithKey CreateBlock(size_t size);
 
 private:
-  std::string CreateRootBlockAndReturnKey();
+  blockstore::Key GetOrCreateRootKey(CryConfig *config);
+  blockstore::Key CreateRootBlockAndReturnKey();
   std::unique_ptr<fspp::Node> Load(const bf::path &path) override;
 
   std::unique_ptr<blockstore::BlockStore> _block_store;
 
-  std::string _root_key;
+  blockstore::Key _root_key;
 
   DISALLOW_COPY_AND_ASSIGN(CryDevice);
 };
diff --git a/src/cryfs_lib/impl/DirBlock.cpp b/src/cryfs_lib/impl/DirBlock.cpp
index 6e2337fe..0c2c7891 100644
--- a/src/cryfs_lib/impl/DirBlock.cpp
+++ b/src/cryfs_lib/impl/DirBlock.cpp
@@ -13,6 +13,7 @@ using std::vector;
 using std::string;
 
 using blockstore::Block;
+using blockstore::Key;
 
 namespace cryfs {
 
@@ -61,12 +62,14 @@ const char *DirBlock::readAndAddNextChild(const char *pos, vector<string> *resul
   return posAfterKey;
 }
 
-void DirBlock::AddChild(const std::string &name, const std::string &blockKey) {
+void DirBlock::AddChild(const std::string &name, const Key &blockKey) {
+  string blockKeyStr = blockKey.AsString();
+
   char *insertPos = entriesEnd();
-  assertEnoughSpaceLeft(insertPos, name.size() + 1 + blockKey.size() + 1);
+  assertEnoughSpaceLeft(insertPos, name.size() + 1 + blockKeyStr.size() + 1);
 
   memcpy(insertPos, name.c_str(), name.size()+1);
-  memcpy(insertPos + name.size()+1, blockKey.c_str(), blockKey.size()+1);
+  memcpy(insertPos + name.size()+1, blockKeyStr.c_str(), blockKeyStr.size()+1);
   ++(*entryCounter());
 }
 
@@ -75,14 +78,14 @@ void DirBlock::assertEnoughSpaceLeft(char *insertPos, size_t insertSize) const {
   assert(usedSize + insertSize <= _block->size());
 }
 
-string DirBlock::GetBlockKeyForName(const string &name) const {
+Key DirBlock::GetBlockKeyForName(const string &name) const {
   unsigned int entryCount = *entryCounter();
   const char *pos = entriesBegin();
   for(unsigned int i = 0; i < entryCount; ++i) {
     size_t name_length = strlen(pos);
     if (name_length == name.size() && 0==std::memcmp(pos, name.c_str(), name_length)) {
       pos += strlen(pos) + 1; // Skip name
-      return pos; // Return key
+      return Key::FromString(pos); // Return key
     }
     pos += strlen(pos) + 1; // Skip name
     pos += strlen(pos) + 1; // Skip key
diff --git a/src/cryfs_lib/impl/DirBlock.h b/src/cryfs_lib/impl/DirBlock.h
index 2defb18d..a33e38d6 100644
--- a/src/cryfs_lib/impl/DirBlock.h
+++ b/src/cryfs_lib/impl/DirBlock.h
@@ -3,6 +3,7 @@
 #define CRYFS_LIB_IMPL_DIRBLOCK_H_
 
 #include <blockstore/interface/Block.h>
+#include <blockstore/utils/Key.h>
 #include "fspp/utils/macros.h"
 
 #include <memory>
@@ -17,8 +18,8 @@ public:
 
   void InitializeEmptyDir();
   std::unique_ptr<std::vector<std::string>> GetChildren() const;
-  void AddChild(const std::string &name, const std::string &blockKey);
-  std::string GetBlockKeyForName(const std::string &name) const;
+  void AddChild(const std::string &name, const blockstore::Key &blockKey);
+  blockstore::Key GetBlockKeyForName(const std::string &name) const;
 
   static bool IsDir(const blockstore::Block &block);