per-vault salt, readme, windows

CMakeLists.txt

@@ -5,8 +5,10 @@ set(CMAKE_CXX_STANDARD 20)
 set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
 
 find_package(Qt6 REQUIRED COMPONENTS Core Widgets)
-find_package(PkgConfig REQUIRED)
-pkg_check_modules(BOTAN REQUIRED botan-3)
+if(NOT WIN32)
+    find_package(PkgConfig REQUIRED)
+    pkg_check_modules(BOTAN REQUIRED botan-3)
+endif()
 
 set(CMAKE_AUTOMOC ON)
 set(CMAKE_AUTORCC ON)

README.md

@@ -0,0 +1,28 @@
+# dull
+
+Desktop app for securely storing sensitive files
+
+## Features
+* **Pretty usable UI**
+* **Overkill encryption:** XChaCha20-Poly1305 + Argon2id(m=1GB,t=8,p=4) key derivation
+* **Cross-platform-ish:** Supports Linux and Windows
+
+## Building
+
+### Debian/Ubuntu
+```
+sudo apt update && sudo apt install build-essential qt6-base-dev libbotan-3-dev cmake
+
+cmake -S . -B build
+cmake --build build -j $(nproc)
+./build/dull
+```
+
+### Windows / MSYS2
+```
+pacman -S --needed mingw-w64-x86_64-toolchain mingw-w64-x86_64-cmake mingw-w64-x86_64-ninja mingw-w64-x86_64-qt6-base mingw-w64-x86_64-qt6-tools mingw-w64-x86_64-libbotan
+
+cmake -S . -B build -DBOTAN_INCLUDE_DIRS=/mingw64/include/botan-3 -DBOTAN_LIBRARIES=/mingw64/lib/libbotan-3.a
+cmake --build build -j $(nproc)
+./build/dull
+```

src/crypto.h

@@ -1,17 +1,12 @@
 #pragma once
 #include "common.h"
 #include <botan/aead.h>
-#include <botan/auto_rng.h>
 #include <botan/hex.h>
 #include <botan/pwdhash.h>
 #include <vector>
 
 namespace Crypto {
 
-// TODO: random salt per per-vault
-const std::vector<u8> SALT = {0xab, 0xfb, 0x45, 0x1,  0x62, 0xcf, 0xd7, 0x46,
-                              0xdf, 0xaf, 0x4e, 0xa9, 0xf0, 0x4b, 0x9f, 0x38};
-
 inline Botan::secure_vector<u8>
 encrypt_xchacha20_poly1305(const Botan::secure_vector<u8> &plaintext,
                            const Botan::secure_vector<u8> &key,
@@ -55,6 +50,7 @@ decrypt_xchacha20_poly1305(const Botan::secure_vector<u8> &ciphertext,
 
 inline Botan::secure_vector<u8>
 derive_key_argon2id(const std::string &password, const std::vector<u8> &salt) {
+  // thousands of years to crack a random 8 char password on a 100 GPUs
   auto pwdhash = Botan::PasswordHashFamily::create_or_throw("Argon2id")
                      ->from_params(static_cast<u64>(1024 * 1024), 8, 4);
 

src/mainwindow.cc

@@ -4,6 +4,7 @@
 #include <QInputDialog>
 #include <QMessageBox>
 #include <QTemporaryFile>
+#include <botan/auto_rng.h>
 #include <botan/hex.h>
 
 MainWindow::MainWindow(QWidget *parent)
@@ -22,15 +23,20 @@ MainWindow::MainWindow(QWidget *parent)
 
     QString password = QInputDialog::getText(
         this, "Choose a password", "Choose a password", QLineEdit::Password);
-    if (password.length() < 5) {
+    if (password.length() < 8) {
       QMessageBox::critical(this, "Error",
-                            "Password must be at least 5 characters long.");
+                            "Password must be at least 8 characters long.");
       return;
     }
 
+    static Botan::AutoSeeded_RNG rng;
+    auto salt_sv = rng.random_vec(16);
+    std::vector<u8> salt(salt_sv.begin(), salt_sv.end());
+
     std::ofstream create(path.toStdString(), std::ios::binary);
     create.write("DULL", 4);
     create.write(to_char_ptr(&VERSION), sizeof(VERSION));
+    create.write(to_char_ptr(salt.data()), 16);
     create.close();
 
     m_vault =
@@ -48,11 +54,6 @@ MainWindow::MainWindow(QWidget *parent)
 
     QString password = QInputDialog::getText(
         this, "Unlock the vault", "Enter vault password", QLineEdit::Password);
-    if (password.length() < 5) {
-      QMessageBox::critical(this, "Error",
-                            "Password must be at least 5 characters long.");
-      return;
-    }
 
     // TODO: check if password valid
 
@@ -100,7 +101,9 @@ void MainWindow::reload_fs_tree() {
     item->setText(2, QString::number(header.offset));
     item->setText(3, QString::fromStdString(Botan::hex_encode(header.nonce)));
   }
-  ui->fsTreeWidget->resizeColumnToContents(0);
+  for (int i = 0; i < ui->fsTreeWidget->columnCount(); ++i) {
+    ui->fsTreeWidget->resizeColumnToContents(i);
+  }
 }
 
 void MainWindow::preview_file(const std::string &filename) {
@@ -159,5 +162,12 @@ void MainWindow::file_context_menu(const QPoint &pos) {
   connect(edit_action, &QAction::triggered, this,
           [this, item]() { edit_file(item->text(0).toStdString()); });
 
+  QAction *delete_action = menu.addAction(
+      style()->standardIcon(QStyle::SP_DialogCancelButton), "Delete");
+  connect(delete_action, &QAction::triggered, this, [this, item]() {
+    m_vault->delete_file(item->text(0).toStdString());
+    reload_fs_tree();
+  });
+
   menu.exec(ui->fsTreeWidget->mapToGlobal(pos));
 }

src/vault.cc

@@ -2,6 +2,7 @@
 #include "common.h"
 #include "crypto.h"
 #include <array>
+#include <botan/auto_rng.h>
 #include <filesystem>
 
 Vault::Vault(std::string path, const std::string &password)
@@ -9,15 +10,19 @@ Vault::Vault(std::string path, const std::string &password)
   m_file.open(m_path, std::ios::in | std::ios::out | std::ios::binary);
   ASSERT(m_file.good());
 
-  m_key = Crypto::derive_key_argon2id(password, Crypto::SALT);
-
-  std::array<char, 4> header{};
-  ASSERT(static_cast<bool>(m_file.read(header.data(), header.size())));
-  ASSERT(std::string_view(header.data(), header.size()) == "DULL");
+  std::array<char, 4> magic{};
+  ASSERT(m_file.read(magic.data(), 4));
+  ASSERT(std::string_view(magic.data(), magic.size()) == "DULL");
 
   i16 version = 0;
   ASSERT(m_file.read(to_char_ptr(&version), sizeof(version)));
   ASSERT(version == VERSION);
+
+  std::vector<u8> salt{};
+  salt.resize(16);
+  ASSERT(m_file.read(to_char_ptr(salt.data()), 16));
+
+  m_key = Crypto::derive_key_argon2id(password, salt);
 }
 
 std::vector<FileHeader> Vault::read_file_headers() {
@@ -77,7 +82,7 @@ void Vault::create_file(const std::string &filename,
 
   Botan::secure_vector<u8> plaintext(content.begin(), content.end());
 
-  Botan::AutoSeeded_RNG rng;
+  static Botan::AutoSeeded_RNG rng;
   auto nonce_sv = rng.random_vec(24);
   std::vector<u8> nonce(nonce_sv.begin(), nonce_sv.end());
 

src/vault.h

@@ -7,7 +7,7 @@
 #include <vector>
 
 constexpr i16 VERSION = 1;
-constexpr u64 AFTER_HEADER_OFFSET = 6;
+constexpr u64 AFTER_HEADER_OFFSET = 22;
 
 struct FileHeader {
   std::string name;