Implements KDBX4 format with Argon2 KDF

* Adds KDBX4 reader/writer interfaces
* Adds KDBX4 XML reader/write interfaces
* Implements test cases for KDBX4
* Fully compatible with KeePass2
* Corrects minor issues with Argon2 KDF

src/format/Kdbx4Reader.h

@@ -0,0 +1,66 @@
+/*
+ *  Copyright (C) 2010 Felix Geyer <debfx@fobos.de>
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 2 or (at your option)
+ *  version 3 of the License.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef KEEPASSX_KDBX4READER_H
+#define KEEPASSX_KDBX4READER_H
+
+#include <QCoreApplication>
+#include <QHash>
+#include <QString>
+#include <QByteArray>
+
+#include "format/KeePass2.h"
+#include "format/KeePass2Reader.h"
+#include "crypto/SymmetricCipher.h"
+#include "keys/CompositeKey.h"
+
+class Database;
+class QIODevice;
+
+class Kdbx4Reader : public BaseKeePass2Reader
+{
+    Q_DECLARE_TR_FUNCTIONS(Kdbx4Reader)
+
+public:
+    Kdbx4Reader();
+
+    using BaseKeePass2Reader::readDatabase;
+    virtual Database* readDatabase(QIODevice* device, const CompositeKey& key, bool keepDatabase = false) override;
+
+    QHash<QString, QByteArray> binaryPool();
+
+private:
+    bool readHeaderField(QIODevice* device);
+    bool readInnerHeaderField(QIODevice* device);
+    QVariantMap readVariantMap(QIODevice* device);
+
+    void setCipher(const QByteArray& data);
+    void setCompressionFlags(const QByteArray& data);
+    void setMasterSeed(const QByteArray& data);
+    void setEncryptionIV(const QByteArray& data);
+    void setProtectedStreamKey(const QByteArray& data);
+    void setInnerRandomStreamID(const QByteArray& data);
+
+    QIODevice* m_device;
+
+    Database* m_db;
+    QByteArray m_masterSeed;
+    QByteArray m_encryptionIV;
+    QHash<QString, QByteArray> m_binaryPool;
+};
+
+#endif // KEEPASSX_KDBX4READER_H