less flushing

.clang-tidy

@@ -1 +1 @@
-Checks: '*,clang-analyzer-*,-llvmlibc-*,-fuchsia-*,-altera-*,-abseil-*,-android-*,-modernize-use-trailing-return-type,-readability-identifier-length,-*-readability-todo,-*-magic-numbers,-readability-function-cognitive-complexity,-*-easily-swappable-parameters,-*-pro-type-reinterpret-cast,-*-owning-memory,-concurrency-mt-unsafe,-cert-env33-c,-*-avoid-do-while'
+Checks: '*,clang-analyzer-*,-llvmlibc-*,-fuchsia-*,-altera-*,-abseil-*,-android-*,-boost-*,-modernize-use-trailing-return-type,-readability-identifier-length,-*-readability-todo,-*-magic-numbers,-readability-function-cognitive-complexity,-*-easily-swappable-parameters,-*-pro-type-reinterpret-cast,-*-owning-memory,-concurrency-mt-unsafe,-cert-env33-c,-*-avoid-do-while'

.gitignore

@@ -2,3 +2,5 @@
 /build
 *.py
 *.dull
+/TODO
+/.clangd

CMakeLists.txt

@@ -21,10 +21,9 @@ set(CMAKE_AUTOUIC ON)
 
 qt6_wrap_ui(UI_HEADERS src/mainwindow.ui)
 
-add_executable(${PROJECT_NAME} src/main.cc src/mainwindow.cc src/vault.cc ${UI_HEADERS})
+add_executable(dull src/main.cc src/mainwindow.cc src/vault.cc ${UI_HEADERS})
 
-target_include_directories(${PROJECT_NAME} PRIVATE ${CMAKE_CURRENT_BINARY_DIR} ${BOTAN_INCLUDE_DIRS})
+target_include_directories(dull PRIVATE ${CMAKE_CURRENT_BINARY_DIR} ${BOTAN_INCLUDE_DIRS})
+target_link_libraries(dull Qt6::Core Qt6::Widgets ${BOTAN_LIBRARIES})
 
-target_link_libraries(${PROJECT_NAME} Qt6::Core Qt6::Widgets ${BOTAN_LIBRARIES})
-
-install(TARGETS ${PROJECT_NAME} DESTINATION bin)
+install(TARGETS dull DESTINATION bin)

LICENSE

@@ -1,4 +1,4 @@
-BSD 3-Clause License
+BSD 2-Clause License
 
 Copyright (c) 2025-2026, Antoni Piasecki
 
@@ -12,10 +12,6 @@ modification, are permitted provided that the following conditions are met:
    this list of conditions and the following disclaimer in the documentation
    and/or other materials provided with the distribution.
 
-3. Neither the name of the copyright holder nor the names of its
-   contributors may be used to endorse or promote products derived from
-   this software without specific prior written permission.
-
 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE

README.md

@@ -3,9 +3,8 @@
 Desktop app for securely storing sensitive files
 
 ## Features
-* **Pretty usable UI**
-* **Overkill encryption:** XChaCha20-Poly1305 + Argon2id key derivation
 * **Cross-platform:** Tested on Linux, Windows and macOS
+* **Overkill encryption:** XChaCha20-Poly1305 + Argon2id key derivation
 * **Drag and Drop support**
 
 ## Building

src/common.h

@@ -14,13 +14,10 @@
   } while (0)
 
 using u8 = uint8_t;
-using i16 = int16_t;
 using u16 = uint16_t;
 using i32 = int32_t;
 using u32 = uint32_t;
 using i64 = int64_t;
 using u64 = uint64_t;
-static_assert(sizeof(float) * 8 == 32);
-using f32 = float;
 static_assert(sizeof(double) * 8 == 64);
 using f64 = double;

src/crypto.h

@@ -1,5 +1,6 @@
 #pragma once
 #include "common.h"
+#include <algorithm>
 #include <botan/aead.h>
 #include <botan/auto_rng.h>
 #include <botan/pwdhash.h>
@@ -14,19 +15,19 @@ inline Botan::secure_vector<u8> encrypt(const Botan::secure_vector<u8> &key,
 
   // XChaCha20 is selected automatically based on the nonce size
   // https://github.com/randombit/botan/blob/master/src/lib/stream/chacha/chacha.cpp#L375
-  static auto cipher = Botan::AEAD_Mode::create_or_throw(
+  static thread_local auto cipher = Botan::AEAD_Mode::create_or_throw(
       "ChaCha20Poly1305", Botan::Cipher_Dir::Encryption);
+  cipher->clear();
 
   auto nonce = rng.random_array<24>();
   cipher->set_key(key);
   cipher->start(nonce);
 
-  Botan::secure_vector<u8> ciphertext(plaintext.begin(), plaintext.end());
-  cipher->finish(ciphertext);
-
   Botan::secure_vector<u8> res;
-  res.insert(res.end(), nonce.begin(), nonce.end());
-  res.insert(res.end(), ciphertext.begin(), ciphertext.end());
+  res.resize(24 + plaintext.size());
+  std::ranges::copy(nonce, res.begin());
+  std::ranges::copy(plaintext, res.begin() + 24);
+  cipher->finish(res, 24);
   return res;
 }
 
@@ -39,8 +40,9 @@ decrypt(const Botan::secure_vector<u8> &key,
   std::array<u8, 24> nonce{};
   std::copy_n(ciphertext_with_nonce.begin(), 24, nonce.begin());
 
-  auto cipher = Botan::AEAD_Mode::create_or_throw(
+  static thread_local auto cipher = Botan::AEAD_Mode::create_or_throw(
       "ChaCha20Poly1305", Botan::Cipher_Dir::Decryption);
+  cipher->clear();
 
   cipher->set_key(key);
   cipher->start(nonce);

src/mainwindow.cc

@@ -9,6 +9,7 @@
 #include <QTemporaryDir>
 #include <array>
 #include <botan/exceptn.h>
+#include <stdexcept>
 
 namespace {
 
@@ -69,10 +70,9 @@ MainWindow::MainWindow(QWidget *parent)
     ui->statusbar->showMessage("Creating the vault...");
     QCoreApplication::processEvents();
 
-    Vault::create(path.toStdString(), password.toStdString());
-
     m_vault =
-        std::make_unique<Vault>(path.toStdString(), password.toStdString());
+        Vault::create_and_open(path.toStdString(), password.toStdString());
+
     ui->statusbar->showMessage("Opened " + path);
 
     reload_fs_tree();
@@ -133,6 +133,7 @@ MainWindow::MainWindow(QWidget *parent)
       file.read(content.data(), size);
       m_vault->create_file(basename(path.toStdString()), content);
     }
+    m_vault->flush();
 
     reload_fs_tree();
     ui->statusbar->showMessage("Added " + QString::number(paths.size()) +
@@ -150,17 +151,14 @@ MainWindow::MainWindow(QWidget *parent)
       return;
     }
 
-    auto headers = m_vault->read_file_headers();
-    for (const auto &header : headers) {
-      auto content = m_vault->read_file(header.name);
-      if (content) {
-        ui->statusbar->showMessage("Extracting " +
-                                   QString::fromStdString(header.name) + "...");
-        QCoreApplication::processEvents();
-        std::ofstream file(path.toStdString() + "/" + header.name,
-                           std::ios::binary);
-        file.write(content->data(), static_cast<i64>(content->size()));
-      }
+    const auto &file_map = m_vault->file_map();
+    for (const auto &[k, _] : file_map) {
+      auto content = m_vault->read_file(k);
+      ui->statusbar->showMessage("Extracting " + QString::fromStdString(k) +
+                                 "...");
+      QCoreApplication::processEvents();
+      std::ofstream file(path.toStdString() + "/" + k, std::ios::binary);
+      file.write(content.data(), static_cast<i64>(content.size()));
     }
     ui->statusbar->showMessage("Extracted all files to " + path);
   });
@@ -171,13 +169,13 @@ void MainWindow::reload_fs_tree() {
   ui->menuFiles->setEnabled(true);
   ui->fsTreeWidget->clear();
 
-  auto headers = m_vault->read_file_headers();
-  for (const auto &header : headers) {
+  const auto &file_map = m_vault->file_map();
+  for (const auto &[k, v] : file_map) {
     auto *item = new QTreeWidgetItem(ui->fsTreeWidget);
     item->setIcon(0, style()->standardIcon(QStyle::SP_FileIcon));
-    item->setText(0, QString::fromStdString(header.name));
-    item->setText(1, QString::fromStdString(
-                         format_bytes(header.content_ciphertext_size)));
+    item->setText(0, QString::fromStdString(k));
+    item->setText(
+        1, QString::fromStdString(format_bytes(v.content_ciphertext_size)));
   }
   for (int i = 0; i < ui->fsTreeWidget->columnCount(); ++i) {
     ui->fsTreeWidget->resizeColumnToContents(i);
@@ -187,17 +185,17 @@ void MainWindow::reload_fs_tree() {
 void MainWindow::preview_file(const std::string &filename) {
   ui->filePreview->setVisible(true);
 
-  auto content = m_vault->read_file(filename);
-  if (content) {
-    ui->filePreview->setText(QString::fromStdString(content.value()));
-  } else {
+  try {
+    auto content = m_vault->read_file(filename);
+    ui->filePreview->setText(QString::fromStdString(content));
+  } catch (std::out_of_range &) {
     qWarning() << "File to preview not found";
   }
 }
 
 void MainWindow::extract_file(const std::string &filename) {
-  auto content = m_vault->read_file(filename);
-  if (content) {
+  try {
+    auto content = m_vault->read_file(filename);
     QString path = QFileDialog::getSaveFileName(
         this, "Choose location to extract",
         QDir::currentPath() + "/" + QString::fromStdString(filename));
@@ -206,24 +204,24 @@ void MainWindow::extract_file(const std::string &filename) {
     }
 
     std::ofstream file(path.toStdString(), std::ios::binary);
-    file.write(content->data(), static_cast<i64>(content->size()));
+    file.write(content.data(), static_cast<i64>(content.size()));
 
     ui->statusbar->showMessage("Extracted to " + path);
-  } else {
+  } catch (std::out_of_range &) {
     qWarning() << "File to extract not found";
   }
 }
 
 void MainWindow::open_file(const std::string &filename) {
-  auto content = m_vault->read_file(filename);
-  if (content) {
+  try {
+    auto content = m_vault->read_file(filename);
     QTemporaryDir dir;
     ASSERT(dir.isValid());
 
     std::string path = dir.path().toStdString() + "/" + filename;
 
     std::ofstream file(path);
-    file.write(content->data(), static_cast<i64>(content->size()));
+    file.write(content.data(), static_cast<i64>(content.size()));
     file.close();
 
     QDesktopServices::openUrl(
@@ -232,21 +230,21 @@ void MainWindow::open_file(const std::string &filename) {
                              "Click OK to delete the opened file.");
 
     // QTemporaryDir gets deleted when it goes out of scope
-  } else {
+  } catch (std::out_of_range &) {
     qWarning() << "File to open not found";
   }
 }
 
 void MainWindow::edit_file(const std::string &filename) {
-  auto content = m_vault->read_file(filename);
-  if (content) {
+  try {
+    auto content = m_vault->read_file(filename);
     QTemporaryDir dir;
     ASSERT(dir.isValid());
 
     std::string path = dir.path().toStdString() + "/" + filename;
 
     std::ofstream file(path);
-    file.write(content->data(), static_cast<i64>(content->size()));
+    file.write(content.data(), static_cast<i64>(content.size()));
     file.close();
 
     QDesktopServices::openUrl(
@@ -255,16 +253,18 @@ void MainWindow::edit_file(const std::string &filename) {
                              "Please edit the file in the opened editor and "
                              "save it. Click OK when done.");
 
-    std::ifstream file2(path, std::ios::binary);
-    std::string new_content((std::istreambuf_iterator<char>(file2)),
-                            std::istreambuf_iterator<char>());
-
+    std::ifstream file2(path, std::ios::binary | std::ios::ate);
+    ASSERT(file2.good());
+    auto size = file2.tellg();
+    file2.seekg(0);
+    std::string new_content(size, '\0');
+    file2.read(new_content.data(), size);
     m_vault->update_file(filename, new_content);
     reload_fs_tree();
 
     ui->statusbar->showMessage("File updated");
     // QTemporaryDir gets deleted when it goes out of scope
-  } else {
+  } catch (std::out_of_range &) {
     qWarning() << "File to edit not found";
   }
 }
@@ -304,6 +304,7 @@ void MainWindow::file_context_menu(const QPoint &pos) {
       style()->standardIcon(QStyle::SP_DialogCancelButton), "Delete");
   connect(delete_action, &QAction::triggered, this, [this, item]() {
     m_vault->delete_file(item->text(0).toStdString());
+    m_vault->flush();
     reload_fs_tree();
   });
 
@@ -346,6 +347,7 @@ void MainWindow::dropEvent(QDropEvent *event) {
     file.read(content.data(), size);
     m_vault->create_file(basename(u.toLocalFile().toStdString()), content);
   }
+  m_vault->flush();
   ui->statusbar->showMessage(
       "Added " + QString::number(event->mimeData()->urls().size()) + " files");
   reload_fs_tree();

src/vault.cc

@@ -31,7 +31,7 @@ Vault::Vault(std::string path, const std::string &password)
   ASSERT(m_file.read(magic.data(), 4));
   ASSERT(std::string_view(magic.data(), magic.size()) == "DULL");
 
-  i16 version = 0;
+  u16 version = 0;
   ASSERT(m_file.read(to_char_ptr(&version), sizeof(version)));
   ASSERT(version == VERSION);
 
@@ -45,9 +45,12 @@ Vault::Vault(std::string path, const std::string &password)
   ASSERT(m_file.read(to_char_ptr(check_ciphertext.data()), 46));
 
   Crypto::decrypt(m_key, check_ciphertext);
+
+  build_file_map();
 }
 
-void Vault::create(const std::string &path, const std::string &password) {
+std::unique_ptr<Vault> Vault::create_and_open(const std::string &path,
+                                              const std::string &password) {
   static Botan::AutoSeeded_RNG rng;
   auto salt = rng.random_array<16>();
 
@@ -62,10 +65,12 @@ void Vault::create(const std::string &path, const std::string &password) {
   WRITE(file, to_char_ptr(salt.data()), 16);
   WRITE(file, to_char_ptr(check_ciphertext.data()), 46);
   file.close();
+
+  return std::make_unique<Vault>(path, password);
 }
 
-std::vector<FileHeader> Vault::read_file_headers() {
-  std::vector<FileHeader> headers;
+void Vault::build_file_map() {
+  m_file_map.clear();
 
   m_file.clear();
   m_file.seekg(AFTER_HEADER_OFFSET, std::ios::beg);
@@ -74,7 +79,7 @@ std::vector<FileHeader> Vault::read_file_headers() {
     auto header = read_file_header();
     if (header) {
       if (!header->deleted) {
-        headers.push_back(header.value());
+        m_file_map[header->name] = header.value();
       }
       m_file.seekg(static_cast<i64>(header->content_ciphertext_size),
                    std::ios::cur);
@@ -82,103 +87,89 @@ std::vector<FileHeader> Vault::read_file_headers() {
       break;
     }
   }
-
-  return headers;
 }
 
-std::optional<std::string> Vault::read_file(const std::string &filename) {
+std::string Vault::read_file(const std::string &name) {
+  auto header = m_file_map.at(name);
+  ASSERT(!header.deleted);
+
   m_file.clear();
-  m_file.seekg(AFTER_HEADER_OFFSET, std::ios::beg);
+  m_file.seekg(static_cast<i64>(header.content_offset), std::ios::beg);
 
-  while (true) {
-    auto header = read_file_header();
-    if (!header) {
-      break;
-    }
+  Botan::secure_vector<u8> ciphertext;
+  ciphertext.resize(header.content_ciphertext_size);
+  ASSERT(m_file.read(to_char_ptr(ciphertext.data()),
+                     static_cast<i64>(header.content_ciphertext_size)));
 
-    if (!header->deleted && header->name == filename) {
-      Botan::secure_vector<u8> ciphertext;
-      ciphertext.resize(header->content_ciphertext_size);
-      if (!m_file.read(to_char_ptr(ciphertext.data()),
-                       static_cast<i64>(header->content_ciphertext_size))) {
-        break;
-      }
-
-      auto plaintext = Crypto::decrypt(m_key, ciphertext);
-      return std::string(to_char_ptr(plaintext.data()), plaintext.size());
-    }
-
-    m_file.seekg(static_cast<i64>(header->content_ciphertext_size),
-                 std::ios::cur);
-  }
-
-  return std::nullopt;
+  auto plaintext = Crypto::decrypt(m_key, ciphertext);
+  return {to_char_ptr(plaintext.data()), plaintext.size()};
 }
 
-void Vault::create_file(const std::string &filename,
-                        const std::string &content) {
+void Vault::create_file(const std::string &name, const std::string &content) {
+  ASSERT(!m_file_map.contains(name));
+
   m_file.clear();
   m_file.seekp(0, std::ios::end);
 
-  auto filename_ciphertext = Crypto::encrypt(m_key, to_span(filename));
-  u64 filename_ciphertext_size = filename_ciphertext.size();
+  auto offset = m_file.tellp();
+
+  auto name_ciphertext = Crypto::encrypt(m_key, to_span(name));
+  u64 name_ciphertext_size = name_ciphertext.size();
 
   auto ciphertext = Crypto::encrypt(m_key, to_span(content));
   u64 ciphertext_size = ciphertext.size();
 
   bool deleted = false;
   WRITE(m_file, &deleted, sizeof(bool)); // deleted flag
-  WRITE(m_file, &filename_ciphertext_size, sizeof(u64));
-  WRITE(m_file, filename_ciphertext.data(), filename_ciphertext_size);
+  WRITE(m_file, &name_ciphertext_size, sizeof(u64));
+  WRITE(m_file, name_ciphertext.data(), name_ciphertext_size);
   WRITE(m_file, &ciphertext_size, sizeof(u64));
+  auto content_offset = m_file.tellp();
   WRITE(m_file, ciphertext.data(), ciphertext_size);
-  m_file.flush();
+
+  m_file_map[name] = FileHeader{
+      .offset = static_cast<u64>(offset),
+      .deleted = false,
+      .name_ciphertext_size = name_ciphertext_size,
+      .name = name,
+      .content_ciphertext_size = ciphertext_size,
+      .content_offset = static_cast<u64>(content_offset),
+  };
 }
 
-void Vault::delete_file(const std::string &filename) {
+void Vault::delete_file(const std::string &name) {
+  auto header = m_file_map.at(name);
+
+  // zero the ciphertext and mark as deleted
   m_file.clear();
-  m_file.seekg(AFTER_HEADER_OFFSET, std::ios::beg);
-
-  while (true) {
-    i64 current_pos = m_file.tellg();
-
-    auto header = read_file_header();
-    if (!header) {
-      break;
-    }
-
-    if (!header->deleted && header->name == filename) {
-      // zero the ciphertext and mark as deleted
-      m_file.seekp(m_file.tellg());
-      std::array<u8, 4096> zeros = {0};
-      u64 remaining = header->content_ciphertext_size;
-      while (remaining > 0) {
-        u64 chunk = std::min(remaining, sizeof(zeros));
-        WRITE(m_file, zeros.data(), chunk);
-        remaining -= chunk;
-      }
-
-      m_file.seekp(current_pos, std::ios::beg);
-      bool deleted = true;
-      WRITE(m_file, &deleted, sizeof(bool));
-      m_file.flush();
-      break;
-    }
-
-    m_file.seekg(static_cast<i64>(header->content_ciphertext_size),
-                 std::ios::cur);
+  m_file.seekp(static_cast<i64>(header.content_offset), std::ios::beg);
+  std::array<u8, 4096> zeros = {0};
+  u64 remaining = header.content_ciphertext_size;
+  while (remaining > 0) {
+    u64 chunk = std::min(remaining, sizeof(zeros));
+    WRITE(m_file, zeros.data(), chunk);
+    remaining -= chunk;
   }
+
+  m_file.clear();
+  m_file.seekp(static_cast<i64>(header.offset), std::ios::beg);
+  bool deleted = true;
+  WRITE(m_file, &deleted, sizeof(bool));
+
+  m_file_map.erase(name);
 }
 
-void Vault::update_file(const std::string &filename,
-                        const std::string &content) {
-  delete_file(filename);
-  create_file(filename, content);
+void Vault::update_file(const std::string &name, const std::string &content) {
+  delete_file(name);
+  create_file(name, content);
+  flush();
 }
 
 std::optional<FileHeader> Vault::read_file_header() {
   FileHeader header{};
 
+  header.offset = m_file.tellg();
+
   if (!m_file.read(to_char_ptr(&header.deleted), 1)) {
     return std::nullopt;
   }
@@ -205,5 +196,6 @@ std::optional<FileHeader> Vault::read_file_header() {
     return std::nullopt;
   }
 
+  header.content_offset = m_file.tellg();
   return header;
 }

src/vault.h

@@ -3,37 +3,46 @@
 #include "common.h"
 #include <botan/secmem.h>
 #include <fstream>
+#include <memory>
 #include <optional>
+#include <unordered_map>
 
-constexpr i16 VERSION = 1;
+constexpr u16 VERSION = 1;
 constexpr u64 AFTER_HEADER_OFFSET = 68;
 
-// !!! REMEMBER TO UPDATE entry_total_size IN Vault::delete_file
 struct FileHeader {
+  u64 offset;
   bool deleted;
   u64 name_ciphertext_size;
   std::string name;
   u64 content_ciphertext_size;
+  u64 content_offset;
 };
 
 class Vault {
 public:
   explicit Vault(std::string path, const std::string &password);
 
-  static void create(const std::string &path, const std::string &password);
+  static std::unique_ptr<Vault> create_and_open(const std::string &path,
+                                                const std::string &password);
 
-  std::vector<FileHeader> read_file_headers();
-  std::optional<std::string> read_file(const std::string &name);
+  std::string read_file(const std::string &name);
   void create_file(const std::string &name, const std::string &content);
   void delete_file(const std::string &name);
   void update_file(const std::string &name, const std::string &content);
+  void flush() { m_file.flush(); }
 
   const std::string &path() const { return m_path; }
+  const std::unordered_map<std::string, FileHeader> &file_map() const {
+    return m_file_map;
+  }
 
 private:
   std::string m_path;
   std::fstream m_file;
   Botan::secure_vector<u8> m_key;
+  std::unordered_map<std::string, FileHeader> m_file_map;
 
+  void build_file_map();
   std::optional<FileHeader> read_file_header();
 };