open file without editing action

src/common.h

@@ -2,7 +2,6 @@
 
 #include <cstdint>
 #include <iostream>
-#include <string>
 
 #define ASSERT(cond)                                                           \
   do {                                                                         \
@@ -25,11 +24,3 @@ static_assert(sizeof(float) * 8 == 32);
 using f32 = float;
 static_assert(sizeof(double) * 8 == 64);
 using f64 = double;
-
-template <typename T> constexpr char *to_char_ptr(T *ptr) noexcept {
-  return reinterpret_cast<char *>(ptr);
-}
-
-template <typename T> constexpr const char *to_char_ptr(const T *ptr) noexcept {
-  return reinterpret_cast<const char *>(ptr);
-}

src/crypto.h

@@ -6,23 +6,22 @@
 
 namespace Crypto {
 
-inline Botan::secure_vector<u8>
-encrypt(const Botan::secure_vector<u8> &key,
-        const Botan::secure_vector<u8> &plaintext) {
+inline Botan::secure_vector<u8> encrypt(const Botan::secure_vector<u8> &key,
+                                        const std::span<const u8> &plaintext) {
   ASSERT(key.size() == 32);
 
   static Botan::AutoSeeded_RNG rng;
-  auto nonce = rng.random_array<24>();
 
   // XChaCha20 is selected automatically based on the nonce size
   // https://github.com/randombit/botan/blob/master/src/lib/stream/chacha/chacha.cpp#L375
-  auto cipher = Botan::AEAD_Mode::create_or_throw(
+  static auto cipher = Botan::AEAD_Mode::create_or_throw(
       "ChaCha20Poly1305", Botan::Cipher_Dir::Encryption);
 
+  auto nonce = rng.random_array<24>();
   cipher->set_key(key);
   cipher->start(nonce);
 
-  Botan::secure_vector<u8> ciphertext = plaintext;
+  Botan::secure_vector<u8> ciphertext(plaintext.begin(), plaintext.end());
   cipher->finish(ciphertext);
 
   Botan::secure_vector<u8> res;

src/mainwindow.cc

@@ -7,6 +7,7 @@
 #include <QMessageBox>
 #include <QMimeData>
 #include <QTemporaryDir>
+#include <array>
 #include <botan/exceptn.h>
 
 namespace {
@@ -16,6 +17,21 @@ std::string basename(const std::string &path) {
   return (pos == std::string::npos) ? path : path.substr(pos + 1);
 }
 
+std::string format_bytes(u64 bytes) {
+  const std::array<std::string_view, 5> units = {"B", "KB", "MB", "GB", "TB"};
+  auto size = static_cast<f64>(bytes);
+  i32 unit = 0;
+
+  while (size >= 1024.0 && unit < 5) {
+    size /= 1024.0;
+    ++unit;
+  }
+
+  std::ostringstream out;
+  out << std::fixed << std::setprecision(2) << size << " " << units.at(unit);
+  return out.str();
+}
+
 } // namespace
 
 MainWindow::MainWindow(QWidget *parent)
@@ -106,11 +122,15 @@ MainWindow::MainWindow(QWidget *parent)
     QStringList paths =
         QFileDialog::getOpenFileNames(this, "Choose files to add");
     for (const auto &path : paths) {
-      std::ifstream file(path.toStdString(), std::ios::binary);
-
-      std::string content((std::istreambuf_iterator<char>(file)),
-                          std::istreambuf_iterator<char>());
+      ui->statusbar->showMessage("Adding " + path + "...");
+      QCoreApplication::processEvents();
 
+      std::ifstream file(path.toStdString(), std::ios::binary | std::ios::ate);
+      ASSERT(file.good());
+      auto size = file.tellg();
+      file.seekg(0);
+      std::string content(size, '\0');
+      file.read(content.data(), size);
       m_vault->create_file(basename(path.toStdString()), content);
     }
 
@@ -134,6 +154,9 @@ MainWindow::MainWindow(QWidget *parent)
     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()));
@@ -153,7 +176,8 @@ void MainWindow::reload_fs_tree() {
     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::number(header.content_ciphertext_size));
+    item->setText(1, QString::fromStdString(
+                         format_bytes(header.content_ciphertext_size)));
   }
   for (int i = 0; i < ui->fsTreeWidget->columnCount(); ++i) {
     ui->fsTreeWidget->resizeColumnToContents(i);
@@ -190,6 +214,29 @@ void MainWindow::extract_file(const std::string &filename) {
   }
 }
 
+void MainWindow::open_file(const std::string &filename) {
+  auto content = m_vault->read_file(filename);
+  if (content) {
+    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.close();
+
+    QDesktopServices::openUrl(
+        QUrl::fromLocalFile(QString::fromStdString(path)));
+    QMessageBox::information(this, "Open",
+                             "Click OK to delete the opened file.");
+
+    // QTemporaryDir gets deleted when it goes out of scope
+  } else {
+    qWarning() << "File to open not found";
+  }
+}
+
 void MainWindow::edit_file(const std::string &filename) {
   auto content = m_vault->read_file(filename);
   if (content) {
@@ -230,13 +277,21 @@ void MainWindow::file_context_menu(const QPoint &pos) {
 
   QMenu menu(this);
 
-  QAction *preview_action = menu.addAction(
-      style()->standardIcon(QStyle::SP_FileDialogContentsView), "Preview");
+  QAction *preview_action =
+      menu.addAction(style()->standardIcon(QStyle::SP_FileDialogContentsView),
+                     "Preview as text");
   connect(preview_action, &QAction::triggered, this,
           [this, item]() { preview_file(item->text(0).toStdString()); });
 
-  QAction *edit_action = menu.addAction(
-      style()->standardIcon(QStyle::SP_FileDialogDetailedView), "Edit");
+  QAction *open_action =
+      menu.addAction(style()->standardIcon(QStyle::SP_FileDialogDetailedView),
+                     "Open in external app");
+  connect(open_action, &QAction::triggered, this,
+          [this, item]() { open_file(item->text(0).toStdString()); });
+
+  QAction *edit_action =
+      menu.addAction(style()->standardIcon(QStyle::SP_FileDialogDetailedView),
+                     "Edit in external app");
   connect(edit_action, &QAction::triggered, this,
           [this, item]() { edit_file(item->text(0).toStdString()); });
 
@@ -281,12 +336,14 @@ void MainWindow::dropEvent(QDropEvent *event) {
     if (!u.isLocalFile()) {
       continue;
     }
-    std::ifstream file(u.toLocalFile().toStdString(), std::ios::binary);
+
+    std::ifstream file(u.toLocalFile().toStdString(),
+                       std::ios::binary | std::ios::ate);
     ASSERT(file.good());
-
-    std::string content((std::istreambuf_iterator<char>(file)),
-                        std::istreambuf_iterator<char>());
-
+    auto size = file.tellg();
+    file.seekg(0);
+    std::string content(size, '\0');
+    file.read(content.data(), size);
     m_vault->create_file(basename(u.toLocalFile().toStdString()), content);
   }
   ui->statusbar->showMessage(

src/mainwindow.h

@@ -21,6 +21,7 @@ private:
   void reload_fs_tree();
   void preview_file(const std::string &filename);
   void extract_file(const std::string &filename);
+  void open_file(const std::string &filename);
   void edit_file(const std::string &filename);
   void file_context_menu(const QPoint &pos);
 };

src/vault.cc

@@ -2,7 +2,25 @@
 #include "common.h"
 #include "crypto.h"
 #include <botan/auto_rng.h>
-#include <filesystem>
+
+#define WRITE(file, data, size)                                                \
+  ASSERT(file.write(to_char_ptr(data), static_cast<i64>(size)))
+
+namespace {
+
+template <typename T> constexpr char *to_char_ptr(T *ptr) noexcept {
+  return reinterpret_cast<char *>(ptr);
+}
+
+template <typename T> constexpr const char *to_char_ptr(const T *ptr) noexcept {
+  return reinterpret_cast<const char *>(ptr);
+}
+
+template <typename T> constexpr std::span<const u8> to_span(const T &x) {
+  return std::span<const u8>(reinterpret_cast<const u8 *>(x.data()), x.size());
+}
+
+} // namespace
 
 Vault::Vault(std::string path, const std::string &password)
     : m_path(std::move(path)) {
@@ -36,16 +54,14 @@ void Vault::create(const std::string &path, const std::string &password) {
   auto key = Crypto::derive_key(password, salt);
 
   const std::string_view content = "LETSGO";
-  Botan::secure_vector<u8> content_sv(content.begin(), content.end());
-  auto check_ciphertext = Crypto::encrypt(key, content_sv);
+  auto check_ciphertext = Crypto::encrypt(key, to_span(content));
 
-  std::ofstream create(path, std::ios::binary);
-  create.write("DULL", 4);
-  create.write(to_char_ptr(&VERSION), sizeof(VERSION));
-  create.write(to_char_ptr(salt.data()), 16);
-
-  create.write(to_char_ptr(check_ciphertext.data()), 46);
-  create.close();
+  std::ofstream file(path, std::ios::binary);
+  WRITE(file, "DULL", 4);
+  WRITE(file, to_char_ptr(&VERSION), sizeof(VERSION));
+  WRITE(file, to_char_ptr(salt.data()), 16);
+  WRITE(file, to_char_ptr(check_ciphertext.data()), 46);
+  file.close();
 }
 
 std::vector<FileHeader> Vault::read_file_headers() {
@@ -57,7 +73,9 @@ std::vector<FileHeader> Vault::read_file_headers() {
   while (true) {
     auto header = read_file_header();
     if (header) {
+      if (!header->deleted) {
         headers.push_back(header.value());
+      }
       m_file.seekg(static_cast<i64>(header->content_ciphertext_size),
                    std::ios::cur);
     } else {
@@ -78,7 +96,7 @@ std::optional<std::string> Vault::read_file(const std::string &filename) {
       break;
     }
 
-    if (header->name == filename) {
+    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()),
@@ -102,20 +120,18 @@ void Vault::create_file(const std::string &filename,
   m_file.clear();
   m_file.seekp(0, std::ios::end);
 
-  Botan::secure_vector<u8> filename_sv(filename.begin(), filename.end());
-  auto filename_ciphertext = Crypto::encrypt(m_key, filename_sv);
+  auto filename_ciphertext = Crypto::encrypt(m_key, to_span(filename));
   u64 filename_ciphertext_size = filename_ciphertext.size();
 
-  Botan::secure_vector<u8> content_sv(content.begin(), content.end());
-  auto ciphertext = Crypto::encrypt(m_key, content_sv);
+  auto ciphertext = Crypto::encrypt(m_key, to_span(content));
   u64 ciphertext_size = ciphertext.size();
 
-  ASSERT(m_file.write(to_char_ptr(&filename_ciphertext_size), sizeof(u64)));
-  ASSERT(m_file.write(to_char_ptr(filename_ciphertext.data()),
-                      static_cast<i64>(filename_ciphertext_size)));
-  ASSERT(m_file.write(to_char_ptr(&ciphertext_size), sizeof(u64)));
-  ASSERT(m_file.write(to_char_ptr(ciphertext.data()),
-                      static_cast<i64>(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, &ciphertext_size, sizeof(u64));
+  WRITE(m_file, ciphertext.data(), ciphertext_size);
   m_file.flush();
 }
 
@@ -123,9 +139,6 @@ void Vault::delete_file(const std::string &filename) {
   m_file.clear();
   m_file.seekg(AFTER_HEADER_OFFSET, std::ios::beg);
 
-  i64 entry_start = -1;
-  u64 entry_total_size = 0;
-
   while (true) {
     i64 current_pos = m_file.tellg();
 
@@ -134,48 +147,26 @@ void Vault::delete_file(const std::string &filename) {
       break;
     }
 
-    if (header->name == filename) {
-      entry_start = current_pos;
-      entry_total_size = sizeof(u64) + header->name_ciphertext_size +
-                         sizeof(u64) + header->content_ciphertext_size;
-      m_file.seekg(static_cast<i64>(header->content_ciphertext_size),
-                   std::ios::cur);
-      break;
-    }
-
-    m_file.seekg(static_cast<i64>(header->content_ciphertext_size),
-                 std::ios::cur);
-  }
-
-  if (entry_start != -1) {
-    i64 entry_end = entry_start + static_cast<i64>(entry_total_size);
-
-    i64 read_pos = entry_end;
-    i64 write_pos = entry_start;
-    std::array<u8, 65536> buffer{};
-    while (true) {
-      m_file.clear();
-      m_file.seekg(read_pos);
-      m_file.read(to_char_ptr(buffer.data()), buffer.size());
-      auto bytes = m_file.gcount();
-      if (bytes == 0) {
-        break;
-      }
-
-      m_file.seekp(write_pos);
-      ASSERT(m_file.write(to_char_ptr(buffer.data()), bytes));
-
-      read_pos += bytes;
-      write_pos += bytes;
+    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();
-    m_file.close();
+      break;
+    }
 
-    std::filesystem::resize_file(m_path, write_pos);
-
-    m_file.open(m_path, std::ios::in | std::ios::out | std::ios::binary);
-    ASSERT(m_file.good());
+    m_file.seekg(static_cast<i64>(header->content_ciphertext_size),
+                 std::ios::cur);
   }
 }
 
@@ -188,6 +179,10 @@ void Vault::update_file(const std::string &filename,
 std::optional<FileHeader> Vault::read_file_header() {
   FileHeader header{};
 
+  if (!m_file.read(to_char_ptr(&header.deleted), 1)) {
+    return std::nullopt;
+  }
+
   if (!m_file.read(to_char_ptr(&header.name_ciphertext_size), sizeof(u64))) {
     return std::nullopt;
   }
@@ -201,10 +196,14 @@ std::optional<FileHeader> Vault::read_file_header() {
     return std::nullopt;
   }
 
+  if (!header.deleted) {
     auto name = Crypto::decrypt(m_key, name_ciphertext);
     header.name = std::string(name.begin(), name.end());
+  }
+
   if (!m_file.read(to_char_ptr(&header.content_ciphertext_size), sizeof(u64))) {
     return std::nullopt;
   }
+
   return header;
 }

src/vault.h

@@ -10,6 +10,7 @@ constexpr u64 AFTER_HEADER_OFFSET = 68;
 
 // !!! REMEMBER TO UPDATE entry_total_size IN Vault::delete_file
 struct FileHeader {
+  bool deleted;
   u64 name_ciphertext_size;
   std::string name;
   u64 content_ciphertext_size;