1 files changed, 77 insertions, 0 deletions
diff --git a/lib/crypto/session.h b/lib/crypto/session.h
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+++ b/lib/crypto/session.h
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+// SPDX-FileCopyrightText: 2021 Alexey Andreyev <aa13q@ya.ru>
+//
+// SPDX-License-Identifier: LGPL-2.1-or-later
+
+#pragma once
+
+#ifdef Quotient_E2EE_ENABLED
+
+#include <QDebug>
+#include <olm/olm.h>
+#include "crypto/e2ee.h"
+#include "crypto/message.h"
+#include "crypto/errors.h"
+#include "crypto/qolmaccount.h"
+
+namespace Quotient {
+
+class QOlmAccount;
+class QOlmSession;
+
+
+//! Either an outbound or inbound session for secure communication.
+class QOlmSession
+{
+public:
+    ~QOlmSession();
+    //! Creates an inbound session for sending/receiving messages from a received 'prekey' message.
+    static std::variant<std::unique_ptr<QOlmSession>, OlmError> createInboundSession(QOlmAccount *account, const Message &preKeyMessage);
+    static std::variant<std::unique_ptr<QOlmSession>, OlmError> createInboundSessionFrom(QOlmAccount *account, const QString &theirIdentityKey, const Message &preKeyMessage);
+    static std::variant<std::unique_ptr<QOlmSession>, OlmError> createOutboundSession(QOlmAccount *account, const QString &theirIdentityKey, const QString &theirOneTimeKey);
+    //! Serialises an `QOlmSession` to encrypted Base64.
+    std::variant<QByteArray, OlmError> pickle(const PicklingMode &mode);
+    //! Deserialises from encrypted Base64 that was previously obtained by pickling a `QOlmSession`.
+    static std::variant<std::unique_ptr<QOlmSession>, OlmError> unpickle(const QByteArray &pickled, const PicklingMode &mode);
+    //! Encrypts a plaintext message using the session.
+    Message encrypt(const QString &plaintext);
+
+    //! Decrypts a message using this session. Decoding is lossy, meaing if
+    //! the decrypted plaintext contains invalid UTF-8 symbols, they will
+    //! be returned as `U+FFFD` (�).
+    std::variant<QString, OlmError> decrypt(const Message &message) const;
+
+    //! Get a base64-encoded identifier for this session.
+    QByteArray sessionId() const;
+
+    //! The type of the next message that will be returned from encryption.
+    Message::Type encryptMessageType();
+
+    //! Checker for any received messages for this session.
+    bool hasReceivedMessage() const;
+
+    //! Checks if the 'prekey' message is for this in-bound session.
+    std::variant<bool, OlmError> matchesInboundSession(Message &preKeyMessage);
+
+    friend bool operator<(const QOlmSession& lhs, const QOlmSession& rhs)
+    {
+        return lhs.sessionId() < rhs.sessionId();
+    }
+
+    friend bool operator<(const std::unique_ptr<QOlmSession> &lhs, const std::unique_ptr<QOlmSession> &rhs) {
+        return *lhs < *rhs;
+    }
+
+    QOlmSession(OlmSession* session);
+private:
+    //! Helper function for creating new sessions and handling errors.
+    static OlmSession* create();
+    static std::variant<std::unique_ptr<QOlmSession>, OlmError> createInbound(QOlmAccount *account, const Message& preKeyMessage, bool from = false, const QString& theirIdentityKey = "");
+    OlmSession* m_session;
+};
+
+
+//using QOlmSessionPtr = std::unique_ptr<QOlmSession>;
+
+} //namespace Quotient
+
+#endif // Quotient_E2EE_ENABLED