Add automatic crypted databases open via dotenvs (#1404)

* Rename confusing variables

* Fix some project warnings

* Fix code style

* Add constant for the default page size

* Move KeyFormats enum to CipherSettings

* Fix code style

* Fix memory leak

* Stop relying on CipherDialog for encryption settings management

* Fix code style

* Add .env format for QSettings

* Add automatic crypted databases open via dotenvs

This adds support for `.env` files next to the crypted databases that
are to be opened that contains the needed cipher settings.

The only required one is the plain-text password as a value for the key
with the name of the database like this:

    myCryptedDatabase.sqlite = MyPassword

This way, databases with a different extension are supported too:

    myCryptedDatabase.db = MyPassword

You can also specify a custom page size adding a different line
(anywhere in the file) like this:

    myCryptedDatabase.db_pageSize = 2048

If not specified, `1024` is used.

You can also specify the format of the specified key using the
associated integer id:

    anotherCryptedDatabase.sqlite = 0xCAFEBABE
    anotherCryptedDatabase.sqlite_keyFormat = 1

where `1` means a Raw key. If not specified, `0` is used, which means a
simple text Passphrase.

Dotenv files (`.env`) are already used on other platforms and by
different tools to manage environment variables, and it's recommended
to be ignored from version control systems, so they won't leak.

* Add new files to CMakeLists

* Move DotenvFormat include to the implementation

* Fix build error

* Remove superfluous method

(related to ac51c23)

* Remove superfluous checks

* Fix memory leaks

(introduced by 94bbb46)

* Fix code style

* Make dotenv related variable and comment clearer

* Remove duplicated code

* Remove unused forward declaration

(introduced by e5a0293)

src/CipherDialog.cpp

@@ -49,34 +49,33 @@ CipherDialog::~CipherDialog()
     delete ui;
 }
 
-CipherDialog::KeyFormats CipherDialog::keyFormat() const
+CipherSettings CipherDialog::getCipherSettings() const
 {
-    return static_cast<CipherDialog::KeyFormats>(ui->comboKeyFormat->currentIndex());
-}
+    CipherSettings::KeyFormats keyFormat = CipherSettings::getKeyFormat(ui->comboKeyFormat->currentIndex());
+    QString password = ui->editPassword->text();
+    int pageSize = ui->comboPageSize->itemData(ui->comboPageSize->currentIndex()).toInt();
 
-QString CipherDialog::password() const
-{
-    if(keyFormat() == KeyFormats::Passphrase)
-        return QString("'%1'").arg(ui->editPassword->text().replace("'", "''"));
-    else
-        return QString("\"x'%1'\"").arg(ui->editPassword->text().mid(2));   // Remove the '0x' part at the beginning
-}
+    CipherSettings cipherSettings;
 
-int CipherDialog::pageSize() const
-{
-    return ui->comboPageSize->itemData(ui->comboPageSize->currentIndex()).toInt();
+    cipherSettings.setKeyFormat(keyFormat);
+    cipherSettings.setPassword(password);
+    cipherSettings.setPageSize(pageSize);
+
+    return cipherSettings;
 }
 
 void CipherDialog::checkInputFields()
 {
     if(sender() == ui->comboKeyFormat)
     {
-        if(keyFormat() == KeyFormats::Passphrase)
+        CipherSettings::KeyFormats keyFormat = CipherSettings::getKeyFormat(ui->comboKeyFormat->currentIndex());
+
+        if(keyFormat == CipherSettings::KeyFormats::Passphrase)
         {
             ui->editPassword->setValidator(nullptr);
             ui->editPassword2->setValidator(nullptr);
             ui->editPassword->setPlaceholderText("");
-        } else if(keyFormat() == KeyFormats::RawKey) {
+        } else if(keyFormat == CipherSettings::KeyFormats::RawKey) {
             ui->editPassword->setValidator(rawKeyValidator);
             ui->editPassword2->setValidator(rawKeyValidator);
             ui->editPassword->setPlaceholderText("0x...");

src/CipherDialog.h

@@ -3,6 +3,8 @@
 
 #include <QDialog>
 
+#include "CipherSettings.h"
+
 class QRegExpValidator;
 
 namespace Ui {
@@ -14,21 +16,12 @@ class CipherDialog : public QDialog
     Q_OBJECT
 
 public:
-    enum KeyFormats
-    {
-        Passphrase,
-        RawKey
-    };
-
     // Set the encrypt parameter to true when the dialog is used to encrypt a database;
     // set it to false if the dialog is used to ask the user for the key to decrypt a file.
     explicit CipherDialog(QWidget* parent, bool encrypt);
     ~CipherDialog();
 
-    // Allow read access to the input fields
-    KeyFormats keyFormat() const;
-    QString password() const;
-    int pageSize() const;
+    CipherSettings getCipherSettings() const;
 
 private:
     Ui::CipherDialog* ui;

src/CipherSettings.cpp

@@ -0,0 +1,49 @@
+#include "CipherSettings.h"
+
+CipherSettings::KeyFormats CipherSettings::getKeyFormat() const
+{
+    return keyFormat;
+}
+
+void CipherSettings::setKeyFormat(const KeyFormats &value)
+{
+    keyFormat = value;
+}
+
+QString CipherSettings::getPassword() const
+{
+    if(keyFormat == Passphrase)
+    {
+        QString tempPassword = password;
+
+        tempPassword.replace("'", "''");
+
+        return QString("'%1'").arg(tempPassword);
+    } else {
+        // Remove the '0x' part at the beginning
+        return QString("\"x'%1'\"").arg(password.mid(2));
+    }
+}
+
+void CipherSettings::setPassword(const QString &value)
+{
+    password = value;
+}
+
+int CipherSettings::getPageSize() const
+{
+    if (pageSize == 0)
+        return defaultPageSize;
+
+    return pageSize;
+}
+
+void CipherSettings::setPageSize(int value)
+{
+    pageSize = value;
+}
+
+CipherSettings::KeyFormats CipherSettings::getKeyFormat(int rawKeyFormat)
+{
+    return static_cast<CipherSettings::KeyFormats>(rawKeyFormat);
+}

src/CipherSettings.h

@@ -0,0 +1,34 @@
+#ifndef CIPHERSETTINGS_H
+#define CIPHERSETTINGS_H
+
+#include <QString>
+
+class CipherSettings
+{
+public:
+    enum KeyFormats
+    {
+        Passphrase,
+        RawKey
+    };
+
+    static const int defaultPageSize = 1024;
+
+    KeyFormats getKeyFormat() const;
+    void setKeyFormat(const KeyFormats &value);
+
+    QString getPassword() const;
+    void setPassword(const QString &value);
+
+    int getPageSize() const;
+    void setPageSize(int value);
+
+    static KeyFormats getKeyFormat(int rawKeyFormat);
+
+private:
+    KeyFormats keyFormat;
+    QString password;
+    int pageSize;
+};
+
+#endif // CIPHERSETTINGS_H

src/DotenvFormat.cpp

@@ -0,0 +1,28 @@
+#include "DotenvFormat.h"
+
+#include <QRegularExpression>
+#include <QTextStream>
+
+bool DotenvFormat::readEnvFile(QIODevice &device, QSettings::SettingsMap &map)
+{
+    QTextStream in(&device);
+
+    QString line;
+
+    QRegularExpression keyValueRegex("^\\s*([\\w\\.\\-]+)\\s*=\\s*(.*)\\s*$");
+
+    while (in.readLineInto(&line)) {
+        QRegularExpressionMatch match = keyValueRegex.match(line);
+
+        if (match.capturedLength() < 3) {
+            continue;
+        }
+
+        QString key = match.captured(1);
+        QString value = match.captured(2);
+
+        map.insert(key, value);
+    }
+
+    return true;
+}

src/DotenvFormat.h

@@ -0,0 +1,13 @@
+#ifndef DOTENVFORMAT_H
+#define DOTENVFORMAT_H
+
+#include <QIODevice>
+#include <QSettings>
+
+class DotenvFormat
+{
+public:
+    static bool readEnvFile(QIODevice &device, QSettings::SettingsMap &map);
+};
+
+#endif // DOTENVFORMAT_H

src/MainWindow.cpp

@@ -2530,8 +2530,8 @@ void MainWindow::updateFilter(int column, const QString& value)
 void MainWindow::editEncryption()
 {
 #ifdef ENABLE_SQLCIPHER
-    CipherDialog dialog(this, true);
-    if(dialog.exec())
+    CipherDialog cipherDialog(this, true);
+    if(cipherDialog.exec())
     {
         // Show progress dialog even though we can't provide any detailed progress information but this
         // process might take some time.
@@ -2553,14 +2553,16 @@ void MainWindow::editEncryption()
             file.close();
         }
 
+        CipherSettings cipherSettings = cipherDialog.getCipherSettings();
+
         // Attach a new database using the new settings
         qApp->processEvents();
         if(ok)
-            ok = db.executeSQL(QString("ATTACH DATABASE '%1' AS sqlitebrowser_edit_encryption KEY %2;").arg(db.currentFile() + ".enctemp").arg(dialog.password()),
+            ok = db.executeSQL(QString("ATTACH DATABASE '%1' AS sqlitebrowser_edit_encryption KEY %2;").arg(db.currentFile() + ".enctemp").arg(cipherSettings.getPassword()),
                                false, false);
         qApp->processEvents();
         if(ok)
-            ok = db.executeSQL(QString("PRAGMA sqlitebrowser_edit_encryption.cipher_page_size = %1").arg(dialog.pageSize()), false, false);
+            ok = db.executeSQL(QString("PRAGMA sqlitebrowser_edit_encryption.cipher_page_size = %1").arg(cipherSettings.getPageSize()), false, false);
 
         // Export the current database to the new one
         qApp->processEvents();

src/Settings.h

@@ -2,8 +2,8 @@
 #define SETTINGS_H
 
 #include <QApplication>
-#include <QVariant>
 #include <QHash>
+#include <QVariant>
 
 class Settings
 {

src/sqlitedb.cpp

@@ -2,6 +2,8 @@
 #include "sqlite.h"
 #include "sqlitetablemodel.h"
 #include "CipherDialog.h"
+#include "CipherSettings.h"
+#include "DotenvFormat.h"
 #include "Settings.h"
 
 #include <QFile>
@@ -104,8 +106,8 @@ bool DBBrowserDB::open(const QString& db, bool readOnly)
     dontCheckForStructureUpdates = false;
 
     // Get encryption settings for database file
-    CipherDialog* cipher = nullptr;
-    if(tryEncryptionSettings(db, &isEncrypted, cipher) == false)
+    CipherSettings* cipherSettings = nullptr;
+    if(tryEncryptionSettings(db, &isEncrypted, cipherSettings) == false)
         return false;
 
     // Open database file
@@ -117,14 +119,14 @@ bool DBBrowserDB::open(const QString& db, bool readOnly)
 
     // Set encryption details if database is encrypted
 #ifdef ENABLE_SQLCIPHER
-    if(isEncrypted && cipher)
+    if(isEncrypted && cipherSettings)
     {
-        executeSQL(QString("PRAGMA key = %1").arg(cipher->password()), false, false);
-        if(cipher->pageSize() != 1024)
-            executeSQL(QString("PRAGMA cipher_page_size = %1;").arg(cipher->pageSize()), false, false);
+        executeSQL(QString("PRAGMA key = %1").arg(cipherSettings->getPassword()), false, false);
+        if(cipherSettings->getPageSize() != CipherSettings::defaultPageSize)
+            executeSQL(QString("PRAGMA cipher_page_size = %1;").arg(cipherSettings->getPageSize()), false, false);
     }
 #endif
-    delete cipher;
+    delete cipherSettings;
 
     if (_db)
     {
@@ -172,7 +174,7 @@ bool DBBrowserDB::open(const QString& db, bool readOnly)
     }
 }
 
-bool DBBrowserDB::attach(const QString& filename, QString attach_as)
+bool DBBrowserDB::attach(const QString& filePath, QString attach_as)
 {
     if(!_db)
         return false;
@@ -186,7 +188,7 @@ bool DBBrowserDB::attach(const QString& filename, QString attach_as)
     if(sqlite3_prepare_v2(_db, sql.toUtf8(), sql.toUtf8().length(), &db_vm, nullptr) == SQLITE_OK)
     {
         // Loop through all the databases
-        QFileInfo fi(filename);
+        QFileInfo fi(filePath);
         while(sqlite3_step(db_vm) == SQLITE_ROW)
         {
             QFileInfo path(QString::fromUtf8((const char*)sqlite3_column_text(db_vm, 2)));
@@ -205,38 +207,39 @@ bool DBBrowserDB::attach(const QString& filename, QString attach_as)
                                           qApp->applicationName(),
                                           tr("Please specify the database name under which you want to access the attached database"),
                                           QLineEdit::Normal,
-                                          QFileInfo(filename).baseName()
+                                          QFileInfo(filePath).baseName()
                                           ).trimmed();
     if(attach_as.isNull())
         return false;
 
 #ifdef ENABLE_SQLCIPHER
     // Try encryption settings
-    CipherDialog* cipher = nullptr;
+    CipherSettings* cipherSettings = nullptr;
     bool is_encrypted;
-    if(tryEncryptionSettings(filename, &is_encrypted, cipher) == false)
+    if(tryEncryptionSettings(filePath, &is_encrypted, cipherSettings) == false)
         return false;
 
     // Attach database
     QString key;
-    if(cipher && is_encrypted)
-        key = "KEY " + cipher->password();
-    if(!executeSQL(QString("ATTACH '%1' AS %2 %3").arg(filename).arg(sqlb::escapeIdentifier(attach_as)).arg(key), false))
+    if(cipherSettings && is_encrypted)
+        key = "KEY " + cipherSettings->getPassword();
+    if(!executeSQL(QString("ATTACH '%1' AS %2 %3").arg(filePath).arg(sqlb::escapeIdentifier(attach_as)).arg(key), false))
     {
         QMessageBox::warning(nullptr, qApp->applicationName(), lastErrorMessage);
         return false;
     }
-    if(cipher && cipher->pageSize() != 1024)
+    if(cipherSettings && cipherSettings->getPageSize() != CipherSettings::defaultPageSize)
     {
-        if(!executeSQL(QString("PRAGMA %1.cipher_page_size = %2").arg(sqlb::escapeIdentifier(attach_as)).arg(cipher->pageSize()), false))
+        if(!executeSQL(QString("PRAGMA %1.cipher_page_size = %2").arg(sqlb::escapeIdentifier(attach_as)).arg(cipherSettings->getPageSize()), false))
         {
             QMessageBox::warning(nullptr, qApp->applicationName(), lastErrorMessage);
             return false;
         }
     }
+    delete cipherSettings;
 #else
     // Attach database
-    if(!executeSQL(QString("ATTACH '%1' AS %2").arg(filename).arg(sqlb::escapeIdentifier(attach_as)), false))
+    if(!executeSQL(QString("ATTACH '%1' AS %2").arg(filePath).arg(sqlb::escapeIdentifier(attach_as)), false))
     {
         QMessageBox::warning(nullptr, qApp->applicationName(), lastErrorMessage);
         return false;
@@ -249,16 +252,21 @@ bool DBBrowserDB::attach(const QString& filename, QString attach_as)
     return true;
 }
 
-bool DBBrowserDB::tryEncryptionSettings(const QString& filename, bool* encrypted, CipherDialog*& cipherSettings)
+bool DBBrowserDB::tryEncryptionSettings(const QString& filePath, bool* encrypted, CipherSettings*& cipherSettings)
 {
     lastErrorMessage = tr("Invalid file format");
 
     // Open database file
     sqlite3* dbHandle;
-    if(sqlite3_open_v2(filename.toUtf8(), &dbHandle, SQLITE_OPEN_READONLY, nullptr) != SQLITE_OK)
+    if(sqlite3_open_v2(filePath.toUtf8(), &dbHandle, SQLITE_OPEN_READONLY, nullptr) != SQLITE_OK)
         return false;
 
     // Try reading from database
+
+#ifdef ENABLE_SQLCIPHER
+    bool isDotenvChecked = false;
+#endif
+
     *encrypted = false;
     cipherSettings = nullptr;
     while(true)
@@ -279,32 +287,81 @@ bool DBBrowserDB::tryEncryptionSettings(const QString& filename, bool* encrypted
         {
             sqlite3_finalize(vm);
 #ifdef ENABLE_SQLCIPHER
-            delete cipherSettings;
-            cipherSettings = new CipherDialog(nullptr, false);
-            if(cipherSettings->exec())
-            {
-                // Close and reopen database first to be in a clean state after the failed read attempt from above
-                sqlite3_close(dbHandle);
-                if(sqlite3_open_v2(filename.toUtf8(), &dbHandle, SQLITE_OPEN_READONLY, NULL) != SQLITE_OK)
+            bool foundDotenvPassword = false;
+
+            // Being in a while loop, we don't want to check the same file multiple times
+            if (!isDotenvChecked) {
+                QFile databaseFile(filePath);
+                QFileInfo databaseFileInfo(databaseFile);
+
+                QString databaseDirectoryPath = databaseFileInfo.dir().path();
+                QString databaseFileName(databaseFileInfo.fileName());
+
+                QString dotenvFilePath = databaseDirectoryPath + "/.env";
+                static const QSettings::Format dotenvFormat = QSettings::registerFormat("env", &DotenvFormat::readEnvFile, nullptr);
+                QSettings dotenv(dotenvFilePath, dotenvFormat);
+
+                QVariant passwordValue = dotenv.value(databaseFileName);
+
+                foundDotenvPassword = !passwordValue.isNull();
+
+                isDotenvChecked = true;
+
+                if (foundDotenvPassword)
                 {
+                    QString password = passwordValue.toString();
+
+                    QVariant keyFormatValue = dotenv.value(databaseFileName + "_keyFormat", QVariant(CipherSettings::KeyFormats::Passphrase));
+                    CipherSettings::KeyFormats keyFormat = CipherSettings::getKeyFormat(keyFormatValue.toInt());
+
+                    QVariant pageSizeValue = dotenv.value(databaseFileName + "_pageSize", QVariant(CipherSettings::defaultPageSize));
+                    int pageSize = pageSizeValue.toInt();
+
                     delete cipherSettings;
-                    cipherSettings = nullptr;
-                    return false;
+                    cipherSettings = new CipherSettings();
+
+                    cipherSettings->setKeyFormat(keyFormat);
+                    cipherSettings->setPassword(password);
+                    cipherSettings->setPageSize(pageSize);
+
                 }
+            }
 
-                // Set key and, if it differs from the default value, the page size
-                sqlite3_exec(dbHandle, QString("PRAGMA key = %1").arg(cipherSettings->password()).toUtf8(), NULL, NULL, NULL);
-                if(cipherSettings->pageSize() != 1024)
-                    sqlite3_exec(dbHandle, QString("PRAGMA cipher_page_size = %1;").arg(cipherSettings->pageSize()).toUtf8(), NULL, NULL, NULL);
-
-                *encrypted = true;
+            if(foundDotenvPassword)
+            {
+                // Skip the CipherDialog prompt for now to test if the dotenv password was correct
             } else {
-                sqlite3_close(dbHandle);
-                *encrypted = false;
+	            CipherDialog *cipherDialog = new CipherDialog(nullptr, false);
+	            if(cipherDialog->exec())
+	            {
+	                delete cipherSettings;
+	                cipherSettings = new CipherSettings(cipherDialog->getCipherSettings());
+	            } else {
+	                sqlite3_close(dbHandle);
+	                *encrypted = false;
+	                delete cipherSettings;
+	                cipherSettings = nullptr;
+	                return false;
+	            }
+	        }
+
+            // Close and reopen database first to be in a clean state after the failed read attempt from above
+            sqlite3_close(dbHandle);
+            if(sqlite3_open_v2(filePath.toUtf8(), &dbHandle, SQLITE_OPEN_READONLY, nullptr) != SQLITE_OK)
+            {
                 delete cipherSettings;
                 cipherSettings = nullptr;
                 return false;
             }
+
+            // Set the key
+            sqlite3_exec(dbHandle, QString("PRAGMA key = %1").arg(cipherSettings->getPassword()).toUtf8(), nullptr, nullptr, nullptr);
+
+            // Set the page size if it differs from the default value
+            if(cipherSettings->getPageSize() != CipherSettings::defaultPageSize)
+                sqlite3_exec(dbHandle, QString("PRAGMA cipher_page_size = %1;").arg(cipherSettings->getPageSize()).toUtf8(), nullptr, nullptr, nullptr);
+
+            *encrypted = true;
 #else
             lastErrorMessage = QString::fromUtf8((const char*)sqlite3_errmsg(dbHandle));
             sqlite3_close(dbHandle);
@@ -540,7 +597,7 @@ void DBBrowserDB::waitForDbRelease()
     }
 }
 
-bool DBBrowserDB::dump(const QString& filename,
+bool DBBrowserDB::dump(const QString& filePath,
     const QStringList& tablesToDump,
     bool insertColNames,
     bool insertNewSyntx,
@@ -551,7 +608,7 @@ bool DBBrowserDB::dump(const QString& filename,
     waitForDbRelease();
 
     // Open file
-    QFile file(filename);
+    QFile file(filePath);
     if(file.open(QIODevice::WriteOnly))
     {
         QApplication::setOverrideCursor(Qt::WaitCursor);
@@ -1650,14 +1707,14 @@ bool DBBrowserDB::setPragma(const QString& pragma, int value, int& originalvalue
     return false;
 }
 
-bool DBBrowserDB::loadExtension(const QString& filename)
+bool DBBrowserDB::loadExtension(const QString& filePath)
 {
     waitForDbRelease();
     if(!_db)
         return false;
 
     // Check if file exists
-    if(!QFile::exists(filename))
+    if(!QFile::exists(filePath))
     {
         lastErrorMessage = tr("File not found.");
         return false;
@@ -1665,7 +1722,7 @@ bool DBBrowserDB::loadExtension(const QString& filename)
 
     // Try to load extension
     char* error;
-    if(sqlite3_load_extension(_db, filename.toUtf8(), nullptr, &error) == SQLITE_OK)
+    if(sqlite3_load_extension(_db, filePath.toUtf8(), nullptr, &error) == SQLITE_OK)
     {
         return true;
     } else {

src/sqlitedb.h

@@ -12,7 +12,7 @@
 #include <QByteArray>
 
 struct sqlite3;
-class CipherDialog;
+class CipherSettings;
 
 enum
 {
@@ -205,7 +205,7 @@ private:
 
     void collationNeeded(void* pData, sqlite3* db, int eTextRep, const char* sCollationName);
 
-    bool tryEncryptionSettings(const QString& filename, bool* encrypted, CipherDialog*& cipherSettings);
+    bool tryEncryptionSettings(const QString& filename, bool* encrypted, CipherSettings*& cipherSettings);
 
     bool dontCheckForStructureUpdates;
 

src/src.pro

@@ -65,7 +65,9 @@ HEADERS += \
     FindReplaceDialog.h \
     ExtendedScintilla.h \
     FileExtensionManager.h \
-    Data.h
+    Data.h \
+    CipherSettings.h \
+    DotenvFormat.h
 
 SOURCES += \
     sqlitedb.cpp \
@@ -107,7 +109,9 @@ SOURCES += \
     FindReplaceDialog.cpp \
     ExtendedScintilla.cpp \
     FileExtensionManager.cpp \
-    Data.cpp
+    Data.cpp \
+    CipherSettings.cpp \
+    DotenvFormat.cpp
 
 RESOURCES += icons/icons.qrc \
              translations/flags/flags.qrc \

src/tests/CMakeLists.txt

@@ -17,6 +17,8 @@ set(TESTSQLOBJECTS_SRC
     ../Settings.cpp
     testsqlobjects.cpp
     ../Data.cpp
+    ../CipherSettings.cpp
+    ../DotenvFormat.cpp
 )
 
 set(TESTSQLOBJECTS_HDR
@@ -32,6 +34,8 @@ set(TESTSQLOBJECTS_MOC_HDR
     ../sqlitetablemodel.h
     ../Settings.h
     testsqlobjects.h
+    ../CipherSettings.h
+    ../DotenvFormat.h
 )
 
 if(sqlcipher)
@@ -92,6 +96,8 @@ set(TESTREGEX_SRC
     ../Settings.cpp
     TestRegex.cpp
     ../Data.cpp
+    ../CipherSettings.cpp
+    ../DotenvFormat.cpp
 )
 
 set(TESTREGEX_HDR
@@ -107,6 +113,8 @@ set(TESTREGEX_MOC_HDR
     ../sqlitetablemodel.h
     ../Settings.h
     TestRegex.h
+    ../CipherSettings.h
+    ../DotenvFormat.h
 )
 
 if(sqlcipher)