Store connection configuration as key value pairs

Add migration for the sqlite database.
Because the Qt SQL library is a bit hard to work with use sqlite through custom wrapper.

pglablib/utils/KeyStrengthener.cpp

@@ -0,0 +1,53 @@
+#include "KeyStrengthener.h"
+#include <botan/base64.h>
+
+KeyStrengthener::KeyStrengthener(std::unique_ptr<Botan::PasswordHash> hasher, Botan::secure_vector<uint8_t> salt, size_t keysize)
+	: m_hasher (std::move(hasher))
+	, m_salt   (std::move(salt))
+	, m_keySize(keysize)
+{}
+
+KeyStrengthener::KeyStrengthener(KeyStrengthener &&rhs)
+	: m_hasher (std::move(rhs.m_hasher))
+	, m_salt   (std::move(rhs.m_salt))
+	, m_keySize(rhs.m_keySize)
+{}
+
+KeyStrengthener &KeyStrengthener::operator=(KeyStrengthener &&rhs)
+{
+	if (&rhs != this) {
+		m_hasher  = std::move(rhs.m_hasher);
+		m_salt    = std::move(rhs.m_salt);
+		m_keySize = rhs.m_keySize;
+	}
+	return *this;
+}
+
+Botan::secure_vector<uint8_t> KeyStrengthener::derive(const std::string &passphrase)
+{
+	Botan::secure_vector<uint8_t> master_key(m_keySize);
+	m_hasher->derive_key(master_key.data(), master_key.size(), passphrase.c_str(), passphrase.length(), m_salt.data(), m_salt.size());
+
+	return master_key;
+}
+
+void KeyStrengthener::saveParams(SQLiteConnection &db, const QString &table_name)
+{
+    size_t i1 = m_hasher->memory_param();
+    size_t i2 = m_hasher->iterations();
+    size_t i3 = m_hasher->parallelism();
+
+	auto salt_str = QString::fromUtf8(Botan::base64_encode(m_salt).c_str());
+	// SAVE parameters in database
+
+    auto stmt = db.Prepare("INSERT OR REPLACE INTO " + table_name + "(id, algo, i1, i2, i3, ks, salt) "
+                           + "VALUES(?1, ?2, ?3, ?4, ?5, ?6, ?7)");
+    stmt.Bind(1, 1);
+    stmt.Bind(2, "Scrypt");
+    stmt.Bind(3, i1);
+    stmt.Bind(4, i2);
+    stmt.Bind(5, i3);
+    stmt.Bind(6, m_keySize);
+    stmt.Bind(7, salt_str);
+    stmt.Step();
+}