Add decryption (and caching) of data, even when adding encryption key after data has been added

7 files changed, 516 insertions, 110 deletions

diff --git a/src/Database.cpp b/src/Database.cpp
index bdf9104..6f864b4 100644
--- a/src/Database.cpp
+++ b/src/Database.cpp
@@ -87,7 +87,7 @@ namespace odhtdb
         onCreateNodeCallbackFunc(nullptr),
         onAddNodeCallbackFunc(nullptr),
         onAddUserCallbackFunc(nullptr),
-        databaseStorage(storageDir)
+        databaseStorage(this, storageDir)
     {
         node.run(port , {
             /*.dht_config = */{
@@ -143,7 +143,9 @@ namespace odhtdb
         // TODO: Use cached files and seed those. If none exists, request new files to seed.
         // If nobody requests my cached files in a long time, request new files to seed and remove cached files
         // (only if there are plenty of other seeders for the cached files. This could also cause race issue 
-        // where all nodes with a cached file delete it at same time)
+        // where all nodes with a cached file delete it at same time).
+        
+        databaseStorage.setNodeDecryptionKey(*nodeToSeed.getRequestHash(), DataView(nodeToSeed.getNodeEncryptionKey()->data, nodeToSeed.getNodeEncryptionKey()->size));
         
         Log::debug("Seeding key: %s", nodeToSeed.getRequestHash()->toString().c_str());
         DhtKey dhtKey(*nodeToSeed.getRequestHash());
@@ -268,12 +270,8 @@ namespace odhtdb
             Encryption encryptedBody(DataView(encryptedSerializer.getBuffer().data(), encryptedSerializer.getBuffer().size()));
             DataView requestData = combine(serializer, encryptedBody);
             shared_ptr<Hash> hashRequestKey = make_shared<Hash>(requestData.data, requestData.size);
-            databaseStorage.createStorage(*hashRequestKey, adminGroup, timestampMicroseconds, (const u8*)requestData.data, requestData.size);
-
-            string nodeNameCopy(nodeName);
-            DatabaseCreateNodeRequest createNodeRequest(hashRequestKey.get(), timestampMicroseconds, nodeAdminUser, move(nodeNameCopy));
-            if(onCreateNodeCallbackFunc)
-                onCreateNodeCallbackFunc(createNodeRequest);
+            databaseStorage.setNodeDecryptionKey(*hashRequestKey, DataView(encryptedBody.getKey().data, encryptedBody.getKey().size));
+            databaseStorage.createStorage(*hashRequestKey, adminGroup, timestampMicroseconds, (const u8*)requestData.data, requestData.size, serializer.getBuffer().size());
 
             stagedCreateObjects.emplace_back(make_unique<StagedObject>(requestData, hashRequestKey));
             
@@ -290,6 +288,19 @@ namespace odhtdb
 
     void Database::addData(const DatabaseNode &nodeInfo, LocalUser *userToPerformActionWith, DataView dataToAdd)
     {
+        if(!userToPerformActionWith->isAllowedToPerformAction(PermissionType::ADD_DATA))
+        {
+            // TODO: User might have permission to perform operation, but we haven't got the packet that adds user to the group with the permission,
+            // or we haven't received the packet that modifies group with the permission to perform the operation.
+            // This also means that an user can be in a group that has permission to perform the operation and then later be removed from it,
+            // and remote peers would accept our request to perform operation if they haven't received the operation that removes the user from the group.
+            // How to handle this?
+            string errMsg = "User ";
+            errMsg += userToPerformActionWith->getName();
+            errMsg += " is not allowed to perform the operation: ADD_USER";
+            throw PermissionDeniedException(errMsg);
+        }
+        
         sibs::SafeSerializer serializer;
         serializer.add(DATABASE_ADD_PACKET_STRUCTURE_VERSION);
         // TODO: Append fractions to get real microseconds time
@@ -301,14 +312,11 @@ namespace odhtdb
         Encryption encryptedBody(dataToAdd, DataView(), encryptionKey);
         DataView requestData = combine(serializer, encryptedBody);
         string signedRequestData = userToPerformActionWith->getPrivateKey().sign(requestData);
-        free(requestData.data);
         DataView stagedAddObject = combine(userToPerformActionWith->getPublicKey(), signedRequestData);
         Hash requestDataHash(stagedAddObject.data, stagedAddObject.size);
-        databaseStorage.appendStorage(*nodeInfo.getRequestHash(), requestDataHash, userToPerformActionWith, timestampMicroseconds, (u8*)stagedAddObject.data, stagedAddObject.size);
-
-        DatabaseAddNodeRequest addNodeRequest(&*nodeInfo.getRequestHash(), &requestDataHash, timestampMicroseconds, userToPerformActionWith, dataToAdd);
-        if(onAddNodeCallbackFunc)
-            onAddNodeCallbackFunc(addNodeRequest);
+        DataView encryptedDataView((char*)requestData.data + serializer.getBuffer().size(), requestData.size - serializer.getBuffer().size());
+        databaseStorage.appendStorage(*nodeInfo.getRequestHash(), requestDataHash, DatabaseOperation::ADD_DATA, userToPerformActionWith, timestampMicroseconds, (u8*)stagedAddObject.data, stagedAddObject.size, encryptedDataView);
+        delete (char*)requestData.data;
 
         stagedAddObjects.emplace_back(make_unique<StagedObject>(stagedAddObject, nodeInfo.getRequestHash()));
     }
@@ -350,8 +358,14 @@ namespace odhtdb
         serializer.add(DatabaseOperation::ADD_USER);
         
         assert(userToAddName.size() <= 255);
+        usize serializedEncryptedDataOffset = serializer.getBuffer().size();
         serializer.add((u8)userToAddName.size());
-        serializer.add((u8*)userToAddName.data(), userToAddName.size());
+        DataView encryptionKey(nodeInfo.getNodeEncryptionKey()->data, ENCRYPTION_KEY_BYTE_SIZE);
+        Encryption encryptedUserName(DataView((void*)userToAddName.data(), userToAddName.size()), DataView(), encryptionKey);
+        serializer.add((u8*)encryptedUserName.getNonce().data, ENCRYPTION_NONCE_BYTE_SIZE);
+        assert(encryptedUserName.getCipherText().size == ENCRYPTION_CHECKSUM_BYTE_SIZE + userToAddName.size());
+        serializer.add((u8*)encryptedUserName.getCipherText().data, ENCRYPTION_CHECKSUM_BYTE_SIZE + userToAddName.size());
+        usize serializedEncryptedDataSize = serializer.getBuffer().size() - serializedEncryptedDataOffset;
         serializer.add((u8*)userToAddPublicKey.getData(), PUBLIC_KEY_NUM_BYTES);
         serializer.add((uint8_t*)groupToAddUserTo->getId().data, groupToAddUserTo->getId().size);
         
@@ -359,13 +373,10 @@ namespace odhtdb
         string signedRequestData = userToPerformActionWith->getPrivateKey().sign(requestData);
         DataView stagedAddObject = combine(userToPerformActionWith->getPublicKey(), signedRequestData);
         Hash requestDataHash(stagedAddObject.data, stagedAddObject.size);
-        databaseStorage.appendStorage(*nodeInfo.getRequestHash(), requestDataHash, userToPerformActionWith, timestampMicroseconds, (u8*)stagedAddObject.data, stagedAddObject.size);
+        DataView encryptedDataView(nullptr, 0);
         auto userToAdd = RemoteUser::create(userToAddPublicKey, userToAddName, groupToAddUserTo);
         databaseStorage.addUser(*nodeInfo.getRequestHash(), userToAdd);
-
-        DatabaseAddUserRequest addUserRequest(&*nodeInfo.getRequestHash(), &requestDataHash, timestampMicroseconds, userToPerformActionWith, userToAdd, groupToAddUserTo);
-        if(onAddUserCallbackFunc)
-            onAddUserCallbackFunc(addUserRequest);
+        databaseStorage.appendStorage(*nodeInfo.getRequestHash(), requestDataHash, DatabaseOperation::ADD_USER, userToPerformActionWith, timestampMicroseconds, (u8*)stagedAddObject.data, stagedAddObject.size, encryptedDataView);
 
         stagedAddObjects.emplace_back(make_unique<StagedObject>(stagedAddObject, nodeInfo.getRequestHash()));
     }
@@ -468,8 +479,8 @@ namespace odhtdb
         deserializer.extract((u8*)creatorPublicKeyRaw, PUBLIC_KEY_NUM_BYTES);
         Signature::PublicKey userPublicKey(creatorPublicKeyRaw, PUBLIC_KEY_NUM_BYTES);
         
-        uint8_t adminGroupId[16];
-        deserializer.extract(adminGroupId, 16);
+        uint8_t adminGroupId[GROUP_ID_LENGTH];
+        deserializer.extract(adminGroupId, GROUP_ID_LENGTH);
         
         if(deserializer.getSize() < ENCRYPTION_NONCE_BYTE_SIZE)
             throw sibs::DeserializeException("Unsigned encrypted body is too small (unable to extract nonce)");
@@ -477,39 +488,7 @@ namespace odhtdb
         auto adminGroup = new Group("administrator", adminGroupId, ADMIN_PERMISSION);
         // TODO: Username is encrypted, we dont know it... unless we have encryption key, in which case we should modify the user name and set it
         auto creatorUser = RemoteUser::create(userPublicKey, "ENCRYPTED USER NAME", adminGroup);
-        databaseStorage.createStorage(hash, adminGroup, creationDate, value->data.data(), value->data.size());
-        
-        u8 nonce[ENCRYPTION_NONCE_BYTE_SIZE];
-        deserializer.extract(nonce, ENCRYPTION_NONCE_BYTE_SIZE);
-        
-        DataView dataToDecrypt((void*)deserializer.getBuffer(), deserializer.getSize());
-        Decryption decryptedBody(dataToDecrypt, DataView(nonce, ENCRYPTION_NONCE_BYTE_SIZE), DataView(encryptionKey->data, ENCRYPTION_KEY_BYTE_SIZE));
-        sibs::SafeDeserializer bodyDeserializer((const u8*)decryptedBody.getDecryptedText().data, decryptedBody.getDecryptedText().size);
-        
-        u8 creatorNameLength = bodyDeserializer.extract<u8>();
-        string creatorName; // TODO: Add this user name to storage added above
-        creatorName.resize(creatorNameLength);
-        bodyDeserializer.extract((u8*)&creatorName[0], creatorNameLength);
-        
-        u8 nameLength = bodyDeserializer.extract<u8>();
-        string name;
-        name.resize(nameLength);
-        bodyDeserializer.extract((u8*)&name[0], nameLength);
-        
-        Log::debug("Got create object, name: %s", name.c_str());
-        DatabaseCreateNodeRequest createNodeRequest(&hash, creationDate, creatorUser, move(name));
-        if(onCreateNodeCallbackFunc)
-            onCreateNodeCallbackFunc(createNodeRequest);
-    }
-    
-    bool isUserAllowedToAddData(const User *user)
-    {
-        for(Group *group : user->getGroups())
-        {
-            if(group->getPermission().getFlag(PermissionType::ADD_DATA))
-                return true;
-        }
-        return false;
+        databaseStorage.createStorage(hash, adminGroup, creationDate, value->data.data(), value->data.size(), value->data.size() - deserializer.getSize());
     }
 
     void Database::deserializeAddRequest(const shared_ptr<dht::Value> &value, const Hash &requestDataHash, const std::shared_ptr<Hash> &nodeHash, const shared_ptr<OwnedMemory> encryptionKey)
@@ -552,21 +531,24 @@ namespace odhtdb
         }
 #endif
         auto creatorUser = databaseStorage.getUserByPublicKey(*nodeHash, creatorPublicKey);
-        // TODO: Verify there isn't already data with same timestamp for this node. Same for quarantine.
-        // TODO: We might receive 'add' data packet before 'create'. If that happens, we should put it in quarantine and process it later.
-        databaseStorage.appendStorage(*nodeHash, requestDataHash, creatorUser, creationDate, value->data.data(), value->data.size());
+        if(!creatorUser)
+        {
+            // TODO: Add to quarantine
+            string errMsg = "User with public key ";
+            errMsg += creatorPublicKey.toString();
+            errMsg += " does not exist in code ";
+            errMsg += nodeHash->toString();
+            throw sibs::DeserializeException(errMsg);
+        }
+        
+        DataView encryptedDataView((void*)deserializerUnsigned.getBuffer(), deserializerUnsigned.getSize());
         
         if(operation == DatabaseOperation::ADD_DATA)
         {
             if(deserializerUnsigned.getSize() < ENCRYPTION_NONCE_BYTE_SIZE)
                 throw sibs::DeserializeException("Unsigned encrypted body is too small (unable to extract nonce)");
             
-            u8 nonce[ENCRYPTION_NONCE_BYTE_SIZE];
-            deserializerUnsigned.extract(nonce, ENCRYPTION_NONCE_BYTE_SIZE);
-            DataView dataToDecrypt((void*)deserializerUnsigned.getBuffer(), deserializerUnsigned.getSize());
-            Decryption decryptedBody(dataToDecrypt, DataView(nonce, ENCRYPTION_NONCE_BYTE_SIZE), DataView(encryptionKey->data, ENCRYPTION_KEY_BYTE_SIZE));
-            
-            if(!isUserAllowedToAddData(creatorUser))
+            if(!creatorUser->isAllowedToPerformAction(PermissionType::ADD_DATA))
             {
                 // TODO: User might have permission to perform operation, but we haven't got the packet that adds user to the group with the permission,
                 // or we haven't received the packet that modifies group with the permission to perform the operation.
@@ -575,34 +557,36 @@ namespace odhtdb
                 // How to handle this?
                 string errMsg = "User ";
                 errMsg += creatorUser->getName();
-                errMsg += " is not allowed to perform the operation: ";
-                errMsg += to_string((u8)operation);
+                errMsg += " is not allowed to add data to node ";
+                errMsg += nodeHash->toString();
                 throw PermissionDeniedException(errMsg);
             }
             
-            Log::debug("Got add object, timestamp: %zu, data: %.*s", creationDate, decryptedBody.getDecryptedText().size, decryptedBody.getDecryptedText().data);
-            const DatabaseAddNodeRequest addNodeRequest(&*nodeHash, &requestDataHash, creationDate, creatorUser, decryptedBody.getDecryptedText());
-            if(onAddNodeCallbackFunc)
-                onAddNodeCallbackFunc(addNodeRequest);
+            // TODO: Verify there isn't already data with same timestamp for this node. Same for quarantine.
+            // TODO: We might receive 'add' data packet before 'create'. If that happens, we should put it in quarantine and process it later.
+            databaseStorage.appendStorage(*nodeHash, requestDataHash, operation, creatorUser, creationDate, value->data.data(), value->data.size(), encryptedDataView);
         }
         else if(operation == DatabaseOperation::ADD_USER)
-        { 
+        {
             u8 nameLength = deserializerUnsigned.extract<u8>();
-            string name;
-            name.resize(nameLength);
-            deserializerUnsigned.extract((u8*)&name[0], nameLength);
+            
+            u8 nonce[ENCRYPTION_NONCE_BYTE_SIZE];
+            deserializerUnsigned.extract(nonce, ENCRYPTION_NONCE_BYTE_SIZE);
+            DataView dataToDecrypt((void*)deserializerUnsigned.getBuffer(), ENCRYPTION_CHECKSUM_BYTE_SIZE + nameLength);
+            
+            sibs::SafeDeserializer deserializerSkippedEncryptedData(deserializerUnsigned.getBuffer() + ENCRYPTION_CHECKSUM_BYTE_SIZE + nameLength, PUBLIC_KEY_NUM_BYTES + GROUP_ID_LENGTH);
             
             char userToAddPublicKeyRaw[PUBLIC_KEY_NUM_BYTES];
-            deserializerUnsigned.extract((u8*)userToAddPublicKeyRaw, PUBLIC_KEY_NUM_BYTES);
+            deserializerSkippedEncryptedData.extract((u8*)userToAddPublicKeyRaw, PUBLIC_KEY_NUM_BYTES);
             Signature::PublicKey userToAddPublicKey(userToAddPublicKeyRaw, PUBLIC_KEY_NUM_BYTES);
             
-            uint8_t groupId[16];
-            deserializerUnsigned.extract(groupId, 16);
+            uint8_t groupId[GROUP_ID_LENGTH];
+            deserializerSkippedEncryptedData.extract(groupId, GROUP_ID_LENGTH);
             
             auto group = databaseStorage.getGroupById(*nodeHash, groupId);
             if(group)
             {
-                auto user = RemoteUser::create(userToAddPublicKey, name, group);
+                auto user = RemoteUser::create(userToAddPublicKey, "ENCRYPTED USER NAME", group);
                 // TODO: What if we receive packets in wrong order? (maliciously or non-maliciously). You would be able to register a user to a group with given name
                 // and further registration would be dropped (even if that is the correct one)
                 if(!databaseStorage.addUser(*nodeHash, user)) return;
@@ -622,10 +606,9 @@ namespace odhtdb
                     throw PermissionDeniedException(errMsg);
                 }
                 
-                Log::debug("Got add user object, timestamp: %zu, user added: %.*s", creationDate, nameLength, name.c_str());
-                DatabaseAddUserRequest addUserRequest(&*nodeHash, &requestDataHash, creationDate, creatorUser, user, group);
-                if(onAddUserCallbackFunc)
-                    onAddUserCallbackFunc(addUserRequest);
+                // TODO: Verify there isn't already data with same timestamp for this node. Same for quarantine.
+                // TODO: We might receive 'add' data packet before 'create'. If that happens, we should put it in quarantine and process it later.
+                databaseStorage.appendStorage(*nodeHash, requestDataHash, operation, creatorUser, creationDate, value->data.data(), value->data.size(), encryptedDataView);
             }
             else
             {
@@ -637,7 +620,7 @@ namespace odhtdb
             string errMsg = "Got unexpected operation: ";
             errMsg += to_string((u8)operation);
             throw sibs::DeserializeException(errMsg);
-        }  
+        }
     }
 
     bool Database::listenCreateData(shared_ptr<dht::Value> value, const Hash &hash, const shared_ptr<OwnedMemory> encryptionKey)
diff --git a/src/DatabaseStorage.cpp b/src/DatabaseStorage.cpp
index 34e6da4..0e9fa32 100644
--- a/src/DatabaseStorage.cpp
+++ b/src/DatabaseStorage.cpp
@@ -7,6 +7,7 @@
 #include "../include/odhtdb/bin2hex.hpp"
 #include "../include/odhtdb/PasswordHash.hpp"
 #include "../include/odhtdb/Log.hpp"
+#include "../include/odhtdb/Database.hpp"
 #include <cstring>
 #include <chrono>
 #include <boost/filesystem/convenience.hpp>
@@ -23,11 +24,21 @@ namespace odhtdb
         STORAGE_TYPE_APPEND
     };
     
+    enum class DecryptedDataType : u8
+    {
+        STORAGE_CREATE,
+        STORAGE_ADD_DATA,
+        STORAGE_ADD_USER
+    };
+    
     const u64 QUARANTINE_STORAGE_TIME_MICROSECONDS = 60 * 1.0e6;
     const u16 STORAGE_VERSION = 1;
-    
-    DatabaseStorageObject::DatabaseStorageObject(DataView &_data, u64 _timestamp, const Signature::PublicKey &_creatorPublicKey) : 
-        data(_data), createdTimestamp(_timestamp), creatorPublicKey(_creatorPublicKey)
+
+    DatabaseStorageObject::DatabaseStorageObject(const Hash &_requestHash, DataView &_data, u64 _timestamp, const Signature::PublicKey &_creatorPublicKey) : 
+        requestHash(_requestHash),
+        data(_data),
+        createdTimestamp(_timestamp), 
+        creatorPublicKey(_creatorPublicKey)
     {
         
     }
@@ -39,12 +50,15 @@ namespace odhtdb
         storedTimestamp = chrono::duration_cast<chrono::microseconds>(time).count();
     }
     
-    DatabaseStorage::DatabaseStorage(const boost::filesystem::path &storagePath) : 
+    DatabaseStorage::DatabaseStorage(Database *_database, const boost::filesystem::path &storagePath) : 
+        database(_database),
         groupsFilePath(storagePath / "groups"),
         usersFilePath(storagePath / "users"),
         dataFilePath(storagePath / "data"),
         metadataFilePath(storagePath / "metadata"),
-        localUsersFilePath(storagePath / "local_users")
+        localUsersFilePath(storagePath / "local_users"),
+        nodeDecryptionKeysFilePath(storagePath / "node_keys"),
+        decryptedDataFilePath(storagePath / "decrypted_data")
     {
         boost::filesystem::create_directories(storagePath);
         
@@ -57,13 +71,21 @@ namespace odhtdb
             loadUsersFromFile();
             loadDataFromFile();
             loadLocalUsersFromFile();
+            loadNodeDecryptionKeysFromFile();
+            loadDecryptedDataFromFile();
             //loadQuarantineFromFile();
         }
         catch(FileException &e)
         {
-            Log::warn("Failed to load storage data, reason: %s. Ignoring...", e.what());
-            if(!metadataLoaded)
+            if(metadataLoaded)
             {
+                string errMsg = "Failed to load storage, reason: ";
+                errMsg += e.what();
+                throw DatabaseStorageCorrupt(errMsg);
+            }
+            else
+            {
+                Log::warn("Failed to load storage meta data, reason: %s. Ignoring... (new storage probably)", e.what());
                 sibs::SafeSerializer metadataSerializer;
                 metadataSerializer.add(STORAGE_VERSION);
                 randombytes_buf(passwordSalt, PASSWORD_SALT_LEN);
@@ -83,6 +105,12 @@ namespace odhtdb
                 fileAppend(metadataFilePath, { metadataSerializer.getBuffer().data(), metadataSerializer.getBuffer().size() });
             }
         }
+        catch(sibs::DeserializeException &e)
+        {
+            string errMsg = "Failed to load storage, reason: ";
+            errMsg += e.what();
+            throw DatabaseStorageCorrupt(errMsg);
+        }
     }
     
     void DatabaseStorage::loadGroupsFromFile()
@@ -122,7 +150,7 @@ namespace odhtdb
             (*groupByIdMap)[group->getId()] = group;
             
             string groupIdStr = bin2hex((const char*)groupId, GROUP_ID_LENGTH);
-            Log::debug("DatabaseStorage: Loaded group from file: %s", groupIdStr.c_str());
+            Log::debug("DatabaseStorage: Loaded group %s from file", groupIdStr.c_str());
         }
     }
     
@@ -194,12 +222,17 @@ namespace odhtdb
     {
         u64 timestamp = deserializer.extract<u64>();
         
+        u8 userPublicKeyRaw[PUBLIC_KEY_NUM_BYTES];
+        deserializer.extract(userPublicKeyRaw, PUBLIC_KEY_NUM_BYTES);
+        Signature::PublicKey userPublicKey((const char*)userPublicKeyRaw, PUBLIC_KEY_NUM_BYTES);
+        
         u8 groupId[GROUP_ID_LENGTH];
         deserializer.extract(groupId, GROUP_ID_LENGTH);
         
         u32 dataSize = deserializer.extract<u32>();
         u8 *data = new u8[dataSize];
         deserializer.extract(data, dataSize);
+        u32 offsetToEncryptedData = deserializer.extract<u32>();
         
         Hash nodeHash;
         deserializer.extract((u8*)nodeHash.getData(), HASH_BYTE_SIZE);
@@ -222,10 +255,11 @@ namespace odhtdb
             throw DatabaseStorageCorrupt(errMsg);
         }
         
-        DatabaseStorageObjectList *databaseStorageObjectList = new DatabaseStorageObjectList();
+        DatabaseStorageObjectList *databaseStorageObjectList = new DatabaseStorageObjectList(userPublicKey);
         databaseStorageObjectList->createdTimestamp = timestamp;
         databaseStorageObjectList->groups.push_back(groupIt->second);
         databaseStorageObjectList->data = DataView(data, dataSize);
+        databaseStorageObjectList->offsetToEncryptedData = offsetToEncryptedData;
         storageMap[nodeHash] = databaseStorageObjectList;
     }
     
@@ -246,7 +280,6 @@ namespace odhtdb
         
         Hash dataHash;
         deserializer.extract((u8*)dataHash.getData(), HASH_BYTE_SIZE);
-        storedDataHash.insert(dataHash);
         
         auto storageIt = storageMap.find(nodeHash);
         if(storageIt == storageMap.end())
@@ -258,8 +291,9 @@ namespace odhtdb
         }
         
         DataView storageData { data, dataSize };
-        DatabaseStorageObject *databaseStorageObject = new DatabaseStorageObject(storageData, timestamp, creatorPublicKey);
+        DatabaseStorageObject *databaseStorageObject = new DatabaseStorageObject(dataHash, storageData, timestamp, creatorPublicKey);
         storageIt->second->objects.push_back(databaseStorageObject);
+        storedDataHash[dataHash] = databaseStorageObject;
     }
     
     void DatabaseStorage::loadDataFromFile()
@@ -310,6 +344,139 @@ namespace odhtdb
         }
     }
     
+    void DatabaseStorage::loadNodeDecryptionKeysFromFile()
+    {
+        if(!boost::filesystem::exists(nodeDecryptionKeysFilePath)) return;
+        
+        OwnedMemory nodeKeysFileContent = fileGetContent(nodeDecryptionKeysFilePath);
+        sibs::SafeDeserializer deserializer((u8*)nodeKeysFileContent.data, nodeKeysFileContent.size);
+        
+        while(!deserializer.empty())
+        {
+            Hash nodeHash;
+            deserializer.extract((u8*)nodeHash.getData(), HASH_BYTE_SIZE);
+            
+            u8 *nodeKeyRaw = new u8[ENCRYPTION_KEY_BYTE_SIZE];
+            deserializer.extract(nodeKeyRaw, ENCRYPTION_KEY_BYTE_SIZE);
+            nodeDecryptionKeyMap[nodeHash] = make_shared<OwnedMemory>(nodeKeyRaw, ENCRYPTION_KEY_BYTE_SIZE);
+        }
+    }
+    
+    void DatabaseStorage::loadDecryptedStorageCreate(sibs::SafeDeserializer &deserializer)
+    {
+        Hash nodeHash;
+        deserializer.extract((u8*)nodeHash.getData(), HASH_BYTE_SIZE);
+        
+        auto storageIt = storageMap.find(nodeHash);
+        if(storageIt == storageMap.end())
+        {
+            string errMsg = "Database storage with hash ";
+            errMsg += nodeHash.toString();
+            errMsg += " not found";
+            throw DatabaseStorageCorrupt(errMsg);
+        }
+        
+        u8 creatorNameLength = deserializer.extract<u8>();
+        auto creator = getUserByPublicKey(nodeHash, storageIt->second->creatorPublicKey);
+        if(!creator)
+        {
+            string errMsg = "User with public key ";
+            errMsg += storageIt->second->creatorPublicKey.toString();
+            errMsg += " does not exist in node with hash ";
+            errMsg += nodeHash.toString();
+            throw DatabaseStorageCorrupt(errMsg);
+        }
+        
+        creator->name.resize(creatorNameLength);
+        deserializer.extract((u8*)&creator->name[0], creatorNameLength);
+        
+        u8 nodeNameLength = deserializer.extract<u8>();
+        storageIt->second->nodeName.resize(nodeNameLength);
+        deserializer.extract((u8*)&storageIt->second->nodeName[0], nodeNameLength);
+        storageIt->second->isDecrypted = true;
+    }
+    
+    void DatabaseStorage::loadDecryptedStorageAddData(sibs::SafeDeserializer &deserializer)
+    {
+        Hash requestHash;
+        deserializer.extract((u8*)requestHash.getData(), HASH_BYTE_SIZE);
+        
+        auto storedDataIt = storedDataHash.find(requestHash);
+        if(storedDataIt == storedDataHash.end())
+        {
+            string errMsg = "Database doesn't contain data with hash ";
+            errMsg += requestHash.toString();
+            throw DatabaseStorageCorrupt(errMsg);
+        }
+        
+        u32 decryptedDataSize = deserializer.extract<u32>();
+        u8 *decryptedDataRaw = new u8[decryptedDataSize];
+        deserializer.extract(decryptedDataRaw, decryptedDataSize);
+        
+        storedDataIt->second->decryptedObject.data.data = decryptedDataRaw;
+        storedDataIt->second->decryptedObject.data.size = decryptedDataSize;
+        storedDataIt->second->decryptedObject.operation = DatabaseOperation::ADD_DATA;
+    }
+    
+    void DatabaseStorage::loadDecryptedStorageAddUser(sibs::SafeDeserializer &deserializer)
+    {
+        Hash nodeHash;
+        deserializer.extract((u8*)nodeHash.getData(), HASH_BYTE_SIZE);
+        
+        Hash requestHash;
+        deserializer.extract((u8*)requestHash.getData(), HASH_BYTE_SIZE);
+        
+        auto storedDataIt = storedDataHash.find(requestHash);
+        if(storedDataIt == storedDataHash.end())
+        {
+            string errMsg = "Database doesn't contain data with hash ";
+            errMsg += requestHash.toString();
+            throw DatabaseStorageCorrupt(errMsg);
+        }
+        
+        u8 addedUserPublicKeyRaw[PUBLIC_KEY_NUM_BYTES];
+        deserializer.extract(addedUserPublicKeyRaw, PUBLIC_KEY_NUM_BYTES);
+        Signature::PublicKey addedUserPublicKey((const char*)addedUserPublicKeyRaw, PUBLIC_KEY_NUM_BYTES);
+        auto addedUser = getUserByPublicKey(nodeHash, addedUserPublicKey);
+        if(!addedUser)
+        {
+            string errMsg = "User with public key ";
+            errMsg += bin2hex((const char*)addedUserPublicKeyRaw, PUBLIC_KEY_NUM_BYTES).c_str();
+            errMsg += " does not exist in node with hash ";
+            errMsg += nodeHash.toString();
+            throw DatabaseStorageCorrupt(errMsg);
+        }
+        
+        u32 decryptedUserNameSize = deserializer.extract<u32>();
+        addedUser->name.resize(decryptedUserNameSize);
+        deserializer.extract((u8*)&addedUser->name[0], decryptedUserNameSize);
+    }
+    
+    void DatabaseStorage::loadDecryptedDataFromFile()
+    {
+        if(!boost::filesystem::exists(decryptedDataFilePath)) return;
+        
+        OwnedMemory decryptedDataFileContent = fileGetContent(decryptedDataFilePath);
+        sibs::SafeDeserializer deserializer((u8*)decryptedDataFileContent.data, decryptedDataFileContent.size);
+        
+        while(!deserializer.empty())
+        {
+            DecryptedDataType decryptedDataType = deserializer.extract<DecryptedDataType>();
+            switch(decryptedDataType)
+            {
+                case DecryptedDataType::STORAGE_CREATE:
+                    loadDecryptedStorageCreate(deserializer);
+                    break;
+                case DecryptedDataType::STORAGE_ADD_DATA:
+                    loadDecryptedStorageAddData(deserializer);
+                    break;
+                case DecryptedDataType::STORAGE_ADD_USER:
+                    loadDecryptedStorageAddUser(deserializer);
+                    break;
+            }
+        }
+    }
+    
     void DatabaseStorage::loadMetadataFromFile()
     {
         OwnedMemory metadataFileContent = fileGetContent(metadataFilePath);
@@ -319,7 +486,6 @@ namespace odhtdb
         if(storageVersion != STORAGE_VERSION)
             throw std::runtime_error("Wrong storage version!");
         
-        u8 passwordSalt[PASSWORD_SALT_LEN];
         deserializer.extract(passwordSalt, PASSWORD_SALT_LEN);
         //string passwordSaltStr((const char*)passwordSalt, PASSWORD_SALT_LEN);
         
@@ -338,7 +504,7 @@ namespace odhtdb
         assert(deserializer.empty());
     }
     
-    void DatabaseStorage::createStorage(const Hash &hash, Group *creatorGroup, u64 timestamp, const u8 *data, usize dataSize)
+    void DatabaseStorage::createStorage(const Hash &hash, Group *creatorGroup, u64 timestamp, const u8 *data, usize dataSize, u32 offsetToEncryptedData)
     {
         if(storageMap.find(hash) != storageMap.end())
         {
@@ -349,32 +515,39 @@ namespace odhtdb
         }
         
         addGroup(hash, creatorGroup);
-        for(auto user : creatorGroup->getUsers())
-        {
-            addUser(hash, (User*)user);
-        }
+        assert(creatorGroup->getUsers().size() == 1);
+        User *creator = (User*)creatorGroup->getUsers()[0];
+        addUser(hash, creator);
         
-        DatabaseStorageObjectList *databaseStorageObjectList = new DatabaseStorageObjectList();
+        DatabaseStorageObjectList *databaseStorageObjectList = new DatabaseStorageObjectList(creator->getPublicKey());
         databaseStorageObjectList->createdTimestamp = timestamp;
         databaseStorageObjectList->groups.push_back(creatorGroup);
         databaseStorageObjectList->data = DataView(new u8[dataSize], dataSize);
         memcpy(databaseStorageObjectList->data.data, data, dataSize);
+        databaseStorageObjectList->offsetToEncryptedData = offsetToEncryptedData;
         storageMap[hash] = databaseStorageObjectList;
         
         sibs::SafeSerializer serializer;
         serializer.add(STORAGE_TYPE_CREATE);
         serializer.add(timestamp);
+        serializer.add((u8*)creator->getPublicKey().getData(), PUBLIC_KEY_NUM_BYTES);
         serializer.add((u8*)creatorGroup->getId().data, GROUP_ID_LENGTH);
         
         serializer.add((u32)dataSize);
         serializer.add(data, dataSize);
+        serializer.add(offsetToEncryptedData);
         
         serializer.add((u8*)hash.getData(), HASH_BYTE_SIZE);
         
         fileAppend(dataFilePath, { serializer.getBuffer().data(), serializer.getBuffer().size() });
+        
+        auto nodeDecryptionKeyIt = nodeDecryptionKeyMap.find(hash);
+        if(nodeDecryptionKeyIt != nodeDecryptionKeyMap.end())
+            decryptNodeData(hash, databaseStorageObjectList, nodeDecryptionKeyIt->second);
     }
     
-    void DatabaseStorage::appendStorage(const Hash &nodeHash, const Hash &dataHash, const User *creatorUser, u64 timestamp, const u8 *data, usize dataSize)
+    // TODO: Use encryptedDataView to remove duplicate of unsigning request, jumping straight to decrypting encrypted data and calling callback func
+    void DatabaseStorage::appendStorage(const Hash &nodeHash, const Hash &dataHash, DatabaseOperation operation, const User *creatorUser, u64 timestamp, const u8 *data, usize dataSize, const DataView &encryptedDataView)
     {
         auto it = storageMap.find(nodeHash);
         if(it == storageMap.end())
@@ -385,8 +558,8 @@ namespace odhtdb
             throw DatabaseStorageNotFound(errMsg);
         }
         
-        auto storeDataHashResult = storedDataHash.insert(dataHash);
-        if(!storeDataHashResult.second)
+        auto storeDataHashResult = storedDataHash.find(dataHash);
+        if(storeDataHashResult != storedDataHash.end())
         {
             string errMsg = "Database already contains data with hash: ";
             errMsg += dataHash.toString();
@@ -395,8 +568,9 @@ namespace odhtdb
         
         DataView storageData { new u8[dataSize], dataSize };
         memcpy(storageData.data, data, dataSize);
-        DatabaseStorageObject *databaseStorageObject = new DatabaseStorageObject(storageData, timestamp, creatorUser->getPublicKey());
+        DatabaseStorageObject *databaseStorageObject = new DatabaseStorageObject(dataHash, storageData, timestamp, creatorUser->getPublicKey());
         it->second->objects.push_back(databaseStorageObject);
+        storedDataHash[dataHash] = databaseStorageObject;
         
         sibs::SafeSerializer serializer;
         serializer.add(STORAGE_TYPE_APPEND);
@@ -410,12 +584,16 @@ namespace odhtdb
         serializer.add((u8*)dataHash.getData(), HASH_BYTE_SIZE);
         
         fileAppend(dataFilePath, { serializer.getBuffer().data(), serializer.getBuffer().size() });
+        
+        auto nodeDecryptionKeyIt = nodeDecryptionKeyMap.find(nodeHash);
+        if(nodeDecryptionKeyIt != nodeDecryptionKeyMap.end())
+            decryptNodeAppendedData(nodeHash, databaseStorageObject, nodeDecryptionKeyIt->second);
     }
     
     void DatabaseStorage::addToQuarantine(const Hash &dataHash, const Signature::PublicKey &creatorPublicKey, u64 timestamp, const u8 *data, usize dataSize)
     {
-        auto storeDataHashResult = storedDataHash.insert(dataHash);
-        if(!storeDataHashResult.second)
+        auto storeDataHashResult = storedDataHash.find(dataHash);
+        if(storeDataHashResult != storedDataHash.end())
         {
             string errMsg = "Database already contains data with hash: ";
             errMsg += dataHash.toString();
@@ -426,6 +604,7 @@ namespace odhtdb
         memcpy(storageData.data, data, dataSize);
         DatabaseStorageQuarantineObject *databaseQuarantineStorageObject = new DatabaseStorageQuarantineObject(storageData, timestamp, creatorPublicKey);
         quarantineStorageMap[creatorPublicKey].emplace_back(databaseQuarantineStorageObject);
+        // TODO: Add quarantine object to storedDataHash
     }
     
     bool DatabaseStorage::addGroup(const Hash &nodeHash, Group *group)
@@ -458,6 +637,8 @@ namespace odhtdb
         serializer.add(group->getPermission().getPermissionFlags());
         
         fileAppend(groupsFilePath, DataView(serializer.getBuffer().data(), serializer.getBuffer().size()));
+
+        Log::debug("Created group %s in node %s", bin2hex((const char*)group->getId().data, GROUP_ID_LENGTH).c_str(), nodeHash.toString().c_str());
         
         return true;
     }
@@ -497,6 +678,8 @@ namespace odhtdb
         }
         
         fileAppend(usersFilePath, DataView(serializer.getBuffer().data(), serializer.getBuffer().size()));
+
+        Log::debug("Created user %s in node %s", user->getPublicKey().toString().c_str(), nodeHash.toString().c_str());
         
         return true;
     }
@@ -612,17 +795,238 @@ namespace odhtdb
                     }
                     
                     (*nodeIt.second)[keyPair.getPublicKey()] = localUser;
-                    localUsers.push_back(make_pair(nodeIt.first, localUser));
+                    localUsers.push_back({ nodeIt.first, localUser });
                     delete user;
                 }
                 else
-                    localUsers.push_back(make_pair(nodeIt.first, static_cast<LocalUser*>(user)));
+                    localUsers.push_back({ nodeIt.first, static_cast<LocalUser*>(user) });
             }
         }
         
         return localUsers;
     }
     
+    void DatabaseStorage::setNodeDecryptionKey(const Hash &nodeHash, const DataView &decryptionKeyView)
+    {  
+        bool nodeHasExistingEncryptionKey = nodeDecryptionKeyMap.find(nodeHash) != nodeDecryptionKeyMap.end();
+        
+        char *decryptionKeyRaw = new char[decryptionKeyView.size];
+        memcpy(decryptionKeyRaw, decryptionKeyView.data, decryptionKeyView.size);
+        shared_ptr<OwnedMemory> decryptionKey = make_shared<OwnedMemory>(decryptionKeyRaw, decryptionKeyView.size);
+        nodeDecryptionKeyMap[nodeHash] = decryptionKey;
+        
+        sibs::SafeSerializer serializer;
+        serializer.add((const u8*)nodeHash.getData(), HASH_BYTE_SIZE);
+        serializer.add((const u8*)decryptionKeyView.data, ENCRYPTION_KEY_BYTE_SIZE);
+        fileAppend(nodeDecryptionKeysFilePath, DataView(serializer.getBuffer().data(), serializer.getBuffer().size()));
+        
+        auto storageIt = storageMap.find(nodeHash);
+        if(storageIt == storageMap.end()) return;
+        
+        // When changing existing encryption key, do not decrypt the existing data as it has already been decrypted,
+        // the new key should only be used for new data
+        if(!nodeHasExistingEncryptionKey)
+            decryptNodeData(nodeHash, storageIt->second, decryptionKey);
+    }
+    
+    bool DatabaseStorage::decryptNodeData(const Hash &nodeHash, DatabaseStorageObjectList *databaseCreateObject, const shared_ptr<OwnedMemory> decryptionKey)
+    {
+        sibs::SafeDeserializer deserializer((u8*)databaseCreateObject->data.data + databaseCreateObject->offsetToEncryptedData, databaseCreateObject->data.size - databaseCreateObject->offsetToEncryptedData);
+        
+        u8 nonce[ENCRYPTION_NONCE_BYTE_SIZE];
+        deserializer.extract(nonce, ENCRYPTION_NONCE_BYTE_SIZE);
+        
+        DataView dataToDecrypt((void*)deserializer.getBuffer(), deserializer.getSize());
+        Decryption decryptedBody(dataToDecrypt, DataView(nonce, ENCRYPTION_NONCE_BYTE_SIZE), DataView(decryptionKey->data, ENCRYPTION_KEY_BYTE_SIZE));
+        sibs::SafeDeserializer bodyDeserializer((const u8*)decryptedBody.getDecryptedText().data, decryptedBody.getDecryptedText().size);
+        
+        u8 creatorNameLength = bodyDeserializer.extract<u8>();
+        string creatorName; // TODO: Add this user name to storage creator name
+        creatorName.resize(creatorNameLength);
+        bodyDeserializer.extract((u8*)&creatorName[0], creatorNameLength);
+        
+        u8 nameLength = bodyDeserializer.extract<u8>();
+        string name;
+        name.resize(nameLength);
+        bodyDeserializer.extract((u8*)&name[0], nameLength);
+        
+        sibs::SafeSerializer serializer;
+        serializer.add(DecryptedDataType::STORAGE_CREATE);
+        serializer.add((const u8*)nodeHash.getData(), HASH_BYTE_SIZE);
+        serializer.add(creatorNameLength);
+        serializer.add((const u8*)creatorName.data(), creatorNameLength);
+        serializer.add(nameLength);
+        serializer.add((const u8*)name.data(), nameLength);
+        fileAppend(decryptedDataFilePath, DataView(serializer.getBuffer().data(), serializer.getBuffer().size()));
+        
+        User *creator = getUserByPublicKey(nodeHash, databaseCreateObject->creatorPublicKey);
+        if(!creator)
+        {
+            Log::error("Creator with public key %s does not exist in node %s", databaseCreateObject->creatorPublicKey.toString().c_str(), nodeHash.toString().c_str());
+            return false;
+        }
+        creator->name = move(creatorName);
+        databaseCreateObject->nodeName = name;
+        databaseCreateObject->isDecrypted = true;
+        
+        Log::debug("Deserialized node create data, name: %s", name.c_str());
+        const DatabaseCreateNodeRequest createNodeRequest(&nodeHash, databaseCreateObject->createdTimestamp, creator, move(name));
+        if(database->onCreateNodeCallbackFunc)
+            database->onCreateNodeCallbackFunc(createNodeRequest);
+        
+        bool success = true;
+        for(auto appendObject : databaseCreateObject->objects)
+        {
+            bool appendObjectResult = decryptNodeAppendedData(nodeHash, appendObject, decryptionKey);
+            if(!appendObjectResult)
+                success = false;
+        }
+        return success;
+    }
+    
+    bool DatabaseStorage::decryptNodeAppendedData(const Hash &nodeHash, DatabaseStorageObject *databaseAppendObject, const shared_ptr<OwnedMemory> decryptionKey)
+    {
+        sibs::SafeDeserializer deserializer((u8*)databaseAppendObject->data.data, databaseAppendObject->data.size);
+        char creatorPublicKeyRaw[PUBLIC_KEY_NUM_BYTES];
+        deserializer.extract((u8*)creatorPublicKeyRaw, PUBLIC_KEY_NUM_BYTES);
+        Signature::PublicKey creatorPublicKey(creatorPublicKeyRaw, PUBLIC_KEY_NUM_BYTES);
+        
+        DataView signedData((void*)deserializer.getBuffer(), deserializer.getSize());
+        string unsignedData = creatorPublicKey.unsign(signedData);
+        sibs::SafeDeserializer deserializerUnsigned((u8*)unsignedData.data(), unsignedData.size());
+        
+        u16 packetStructureVersion = deserializerUnsigned.extract<u16>();
+        u64 creationDate = deserializerUnsigned.extract<u64>();
+        
+        DatabaseOperation operation = deserializerUnsigned.extract<DatabaseOperation>();
+        
+        auto creatorUser = getUserByPublicKey(nodeHash, creatorPublicKey);
+        if(!creatorUser)
+        {
+            Log::error("User with public key %s does not exist in node %s", creatorPublicKey.toString().c_str(), nodeHash.toString().c_str());
+            return false;
+        }
+
+        if(operation == DatabaseOperation::ADD_DATA)
+        {
+            if(deserializerUnsigned.getSize() < ENCRYPTION_NONCE_BYTE_SIZE)
+            {
+                Log::error("Unsigned encrypted body is too small (unable to extract nonce)");
+                return false;
+            }
+#if 0
+            if(!creatorUser->isAllowedToPerformAction(PermissionType::ADD_DATA))
+            {
+                // TODO: User might have permission to perform operation, but we haven't got the packet that adds user to the group with the permission,
+                // or we haven't received the packet that modifies group with the permission to perform the operation.
+                // This also means that an user can be in a group that has permission to perform the operation and then later be removed from it,
+                // and remote peers would accept our request to perform operation if they haven't received the operation that removes the user from the group.
+                // How to handle this?
+                Log::error("User %s is not allowed to add data to node %s", creatorUser->getName().c_str(), nodeHash.toString().c_str());
+                return false;
+            }
+#endif
+            
+            u8 nonce[ENCRYPTION_NONCE_BYTE_SIZE];
+            deserializerUnsigned.extract(nonce, ENCRYPTION_NONCE_BYTE_SIZE);
+            DataView dataToDecrypt((void*)deserializerUnsigned.getBuffer(), deserializerUnsigned.getSize());
+            Decryption decryptedBody(dataToDecrypt, DataView(nonce, ENCRYPTION_NONCE_BYTE_SIZE), DataView(decryptionKey->data, ENCRYPTION_KEY_BYTE_SIZE));
+            
+            sibs::SafeSerializer serializer;
+            serializer.add(DecryptedDataType::STORAGE_ADD_DATA);
+            serializer.add((const u8*)databaseAppendObject->requestHash.getData(), HASH_BYTE_SIZE);
+            serializer.add((u32)decryptedBody.getDecryptedText().size);
+            serializer.add((const u8*)decryptedBody.getDecryptedText().data, decryptedBody.getDecryptedText().size);
+            fileAppend(decryptedDataFilePath, DataView(serializer.getBuffer().data(), serializer.getBuffer().size()));
+            databaseAppendObject->decryptedObject.data.data = new char[decryptedBody.getDecryptedText().size];
+            memcpy(databaseAppendObject->decryptedObject.data.data, decryptedBody.getDecryptedText().data, decryptedBody.getDecryptedText().size);
+            databaseAppendObject->decryptedObject.data.size = decryptedBody.getDecryptedText().size;
+            databaseAppendObject->decryptedObject.operation = operation;
+            
+            Log::debug("Got add object, timestamp: %zu, data: %.*s", creationDate, decryptedBody.getDecryptedText().size, decryptedBody.getDecryptedText().data);
+            const DatabaseAddNodeRequest addNodeRequest(&nodeHash, &databaseAppendObject->requestHash, creationDate, creatorUser, decryptedBody.getDecryptedText());
+            if(database->onAddNodeCallbackFunc)
+                database->onAddNodeCallbackFunc(addNodeRequest);
+        }
+        else if(operation == DatabaseOperation::ADD_USER)
+        { 
+            u8 nameLength = deserializerUnsigned.extract<u8>();
+            
+            u8 nonce[ENCRYPTION_NONCE_BYTE_SIZE];
+            deserializerUnsigned.extract(nonce, ENCRYPTION_NONCE_BYTE_SIZE);
+            DataView dataToDecrypt((void*)deserializerUnsigned.getBuffer(), ENCRYPTION_CHECKSUM_BYTE_SIZE + nameLength);
+            Decryption decryptedUserName(dataToDecrypt, DataView(nonce, ENCRYPTION_NONCE_BYTE_SIZE), DataView(decryptionKey->data, ENCRYPTION_KEY_BYTE_SIZE));
+
+            string username;
+            username.resize(nameLength);
+            assert(decryptedUserName.getDecryptedText().size == nameLength);
+            memcpy(&username[0], decryptedUserName.getDecryptedText().data, nameLength);
+
+            sibs::SafeDeserializer deserializerSkippedEncryptedData(deserializerUnsigned.getBuffer() + ENCRYPTION_CHECKSUM_BYTE_SIZE + nameLength, PUBLIC_KEY_NUM_BYTES + GROUP_ID_LENGTH);
+            
+            char userToAddPublicKeyRaw[PUBLIC_KEY_NUM_BYTES];
+            deserializerSkippedEncryptedData.extract((u8*)userToAddPublicKeyRaw, PUBLIC_KEY_NUM_BYTES);
+            Signature::PublicKey userToAddPublicKey(userToAddPublicKeyRaw, PUBLIC_KEY_NUM_BYTES);
+            
+            uint8_t groupId[GROUP_ID_LENGTH];
+            deserializerSkippedEncryptedData.extract(groupId, GROUP_ID_LENGTH);
+            
+            auto group = getGroupById(nodeHash, groupId);
+            if(!group)
+            {
+                // TODO: Add to quarantine?
+                Log::error("There is no group with id %s in node %s", bin2hex((const char*)groupId, GROUP_ID_LENGTH).c_str(), nodeHash.toString().c_str());
+                return false;
+            }
+            
+            auto user = getUserByPublicKey(nodeHash, userToAddPublicKey);
+            if(!user)
+            {
+                Log::error("User to add with public key %s doesn't exist in node %s", userToAddPublicKey.toString().c_str(), nodeHash.toString().c_str());
+                return false;
+            }
+#if 0
+            auto creatorUserGroupWithRights = getGroupWithRightsToAddUserToGroup(creatorUser->getGroups(), group);
+            if(!creatorUserGroupWithRights)
+            {
+                // TODO: User might have permission to perform operation, but we haven't got the packet that adds user to the group with the permission,
+                // or we haven't received the packet that modifies group with the permission to perform the operation.
+                // This also means that an user can be in a group that has permission to perform the operation and then later be removed from it,
+                // and remote peers would accept our request to perform operation if they haven't received the operation that removes the user from the group.
+                // How to handle this?
+                string errMsg = "User ";
+                errMsg += creatorUser->getName();
+                errMsg += " is not allowed to perform the operation: ";
+                errMsg += to_string((u8)operation);
+                throw PermissionDeniedException(errMsg);
+            }
+#endif
+            sibs::SafeSerializer serializer;
+            serializer.add(DecryptedDataType::STORAGE_ADD_USER);
+            serializer.add((const u8*)nodeHash.getData(), HASH_BYTE_SIZE);
+            serializer.add((const u8*)databaseAppendObject->requestHash.getData(), HASH_BYTE_SIZE);
+            serializer.add((const u8*)userToAddPublicKey.getData(), PUBLIC_KEY_NUM_BYTES);
+            serializer.add((u32)decryptedUserName.getDecryptedText().size);
+            serializer.add((const u8*)decryptedUserName.getDecryptedText().data, decryptedUserName.getDecryptedText().size);
+            fileAppend(decryptedDataFilePath, DataView(serializer.getBuffer().data(), serializer.getBuffer().size()));
+            databaseAppendObject->decryptedObject.data.data = new char[decryptedUserName.getDecryptedText().size];
+            memcpy(databaseAppendObject->decryptedObject.data.data, decryptedUserName.getDecryptedText().data, decryptedUserName.getDecryptedText().size);
+            databaseAppendObject->decryptedObject.data.size = decryptedUserName.getDecryptedText().size;
+            databaseAppendObject->decryptedObject.operation = operation;
+            
+            Log::debug("Got add user object, timestamp: %zu, user added: %.*s", creationDate, nameLength, username.c_str());
+            DatabaseAddUserRequest addUserRequest(&nodeHash, &databaseAppendObject->requestHash, creationDate, creatorUser, user, group);
+            if(database->onAddUserCallbackFunc)
+                database->onAddUserCallbackFunc(addUserRequest);
+        }
+        else
+        {
+            Log::error("Got unexpected operation %d", operation);
+            return false;
+        }
+        return true;
+    }
+    
     const dht::crypto::Identity& DatabaseStorage::getIdentity() const
     {
         return identity;
diff --git a/src/Encryption.cpp b/src/Encryption.cpp
index 1d6bfc0..9000519 100644
--- a/src/Encryption.cpp
+++ b/src/Encryption.cpp
@@ -5,6 +5,8 @@
 
 namespace odhtdb
 {
+    static_assert(ENCRYPTION_CHECKSUM_BYTE_SIZE == crypto_aead_xchacha20poly1305_ietf_ABYTES, "Encryption checksum key size has changed for some reason, oops...");
+    
     Encryption::Encryption(const DataView &data, const DataView &additionalData, const DataView &_key)
     {
         cipherTextLength = crypto_aead_xchacha20poly1305_ietf_ABYTES + data.size;
diff --git a/src/FileUtils.cpp b/src/FileUtils.cpp
index 3a78a63..6dc10b8 100644
--- a/src/FileUtils.cpp
+++ b/src/FileUtils.cpp
@@ -22,6 +22,7 @@ namespace odhtdb
             throw FileException(errMsg);
         }
 
+        flockfile(file);
         fseek(file, 0, SEEK_END);
         size_t fileSize = ftell(file);
         fseek(file, 0, SEEK_SET);
diff --git a/src/Hash.cpp b/src/Hash.cpp
index e46e5ba..364cddd 100644
--- a/src/Hash.cpp
+++ b/src/Hash.cpp
@@ -31,7 +31,7 @@ namespace odhtdb
     
     Hash::Hash(const Hash &other)
     {
-        memcpy(data, other.data, HASH_BYTE_SIZE);
+        memmove(data, other.data, HASH_BYTE_SIZE);
     }
     
     size_t Hash::operator()() const
diff --git a/src/Signature.cpp b/src/Signature.cpp
index 3fd52ee..9f44ad2 100644
--- a/src/Signature.cpp
+++ b/src/Signature.cpp
@@ -122,5 +122,11 @@ namespace odhtdb
         {
             
         }
+        
+        KeyPair::KeyPair(const KeyPair &other)
+        {
+            memmove(publicKey.data, other.publicKey.data, PUBLIC_KEY_NUM_BYTES);
+            memmove(privateKey.data, other.privateKey.data, PRIVATE_KEY_NUM_BYTES);
+        }
     }
 }
diff --git a/src/User.cpp b/src/User.cpp
index d157c74..58e350a 100644
--- a/src/User.cpp
+++ b/src/User.cpp
@@ -26,4 +26,14 @@ namespace odhtdb
             group->addUser(this);
         }
     }
+    
+    bool User::isAllowedToPerformAction(PermissionType action) const
+    {
+        for(Group *group : getGroups())
+        {
+            if(group->getPermission().getFlag(action))
+                return true;
+        }
+        return false;
+    }
 }