E2EE: introduce EncryptedEvent

CMakeLists.txt

@@ -138,6 +138,7 @@ set(libqmatrixclient_SRCS
     lib/events/callinviteevent.cpp
     lib/events/directchatevent.cpp
     lib/events/encryptionevent.cpp
+    lib/events/encryptedevent.cpp
     lib/jobs/requestdata.cpp
     lib/jobs/basejob.cpp
     lib/jobs/syncjob.cpp

lib/events/encryptedevent.cpp

@@ -0,0 +1,28 @@
+#include "encryptedevent.h"
+
+using namespace QMatrixClient;
+
+EncryptedEvent::EncryptedEvent()
+    : RoomEvent(typeId(), matrixTypeId())
+{ }
+
+EncryptedEvent::EncryptedEvent(const QJsonObject &obj)
+    : RoomEvent(typeId(), obj)
+{ }
+
+QString EncryptedEvent::algorithm() const
+{
+    QString algo = content<QString>(AlgorithmKeyL);
+    Q_ASSERT(SupportedAlgorithms.contains(algo));
+    return  algo;
+}
+
+QString EncryptedEvent::ciphertext() const
+{
+    return content<QString>("ciphertext"_ls);
+}
+
+QString EncryptedEvent::senderKey() const
+{
+    return content<QString>("sender_key"_ls);
+}

lib/events/encryptedevent.h

@@ -0,0 +1,55 @@
+#pragma once
+
+#include "roomevent.h"
+#include "e2ee.h"
+
+namespace QMatrixClient
+{
+
+    /*
+     * While the specification states:
+     *
+     * "This event type is used when sending encrypted events.
+     * It can be used either within a room
+     * (in which case it will have all of the Room Event fields),
+     * or as a to-device event."
+     * "The encrypted payload can contain any message event."
+     * https://matrix.org/docs/spec/client_server/latest#id493
+     *
+     * -- for most of the cases the message event is the room message event.
+     * And even for the to-device events the context is for the room.
+     *
+     * So, to simplify integration to the timeline, EncryptedEvent is a RoomEvent inheritor.
+     * Strictly speaking though, it's not always a RoomEvent, but an Event in general.
+     * It's possible, because RoomEvent interface is similar to Event's one
+     * and doesn't add new restrictions, just provides additional features.
+     */
+    class EncryptedEvent : public RoomEvent
+    {
+        Q_GADGET
+    public:
+        DEFINE_EVENT_TYPEID("m.room.encrypted", EncryptedEvent)
+        // recipient Curve25519 identity key
+        EncryptedEvent();
+        explicit EncryptedEvent(const QJsonObject& obj);
+
+        QString algorithm() const;
+        QString ciphertext() const;
+        QString senderKey() const;
+
+        // Required with Megolm:
+        QString deviceId() const;
+        QString sessionId() const;
+
+
+        const event_ptr_tt<RoomEvent>& decryptedEvent() const
+        {
+            return _decryptedEvent;
+        }
+
+        private:
+            event_ptr_tt<RoomEvent> _decryptedEvent;
+    };
+    REGISTER_EVENT_TYPE(EncryptedEvent)
+
+}  // namespace QMatrixClient