1 files changed, 104 insertions, 0 deletions
diff --git a/include/erebos/pairing.h b/include/erebos/pairing.h
new file mode 100644
index 0000000..f0952d8
--- /dev/null
+++ b/include/erebos/pairing.h
@@ -0,0 +1,104 @@
+#pragma once
+
+#include <erebos/identity.h>
+#include <erebos/network.h>
+#include <erebos/service.h>
+
+#include <future>
+#include <map>
+#include <mutex>
+#include <string>
+#include <variant>
+#include <vector>
+
+namespace erebos {
+
+using std::function;
+using std::future;
+using std::map;
+using std::mutex;
+using std::string;
+using std::variant;
+using std::vector;
+
+/**
+ * Template-less base class for the paring functionality that does not depend
+ * on the result parameter.
+ */
+class PairingServiceBase : public Service
+{
+public:
+	typedef function<void(const Peer &)> RequestInitHook;
+	void onRequestInit(RequestInitHook);
+
+	typedef function<future<bool>(const Peer &, string)> ConfirmHook;
+	void onResponse(ConfirmHook);
+	void onRequest(ConfirmHook);
+
+	typedef function<void(const Peer &)> RequestNonceFailedHook;
+	void onRequestNonceFailed(RequestNonceFailedHook);
+
+protected:
+	void requestPairing(UUID serviceId, const Peer & peer);
+	virtual void handle(Context &) override;
+	virtual Ref handlePairingCompleteRef(const Peer &) = 0;
+	virtual void handlePairingResult(Context &) = 0;
+
+private:
+	static vector<uint8_t> nonceDigest(const Identity & id1, const Identity & id2,
+			const vector<uint8_t> & nonce1, const vector<uint8_t> & nonce2);
+	static string confirmationNumber(const vector<uint8_t> &);
+	void waitForConfirmation(Peer peer, string confirm);
+
+	RequestInitHook requestInitHook;
+	ConfirmHook responseHook;
+	ConfirmHook requestHook;
+	RequestNonceFailedHook requestNonceFailedHook;
+
+	optional<Ref> result;
+
+	enum class StatePhase {
+		NoPairing,
+		OurRequest,
+		OurRequestConfirm,
+		OurRequestReady,
+		PeerRequest,
+		PeerRequestConfirm,
+		PairingDone,
+		PairingFailed
+	};
+
+	struct State {
+		StatePhase phase;
+		vector<uint8_t> nonce;
+		vector<uint8_t> peerCheck;
+	};
+
+	map<Peer, State> peerStates;
+	mutex stateLock;
+};
+
+template<class Result>
+class PairingService : public PairingServiceBase
+{
+protected:
+	virtual Stored<Result> handlePairingComplete(const Peer &) = 0;
+	virtual void handlePairingResult(Context &, Stored<Result>) = 0;
+
+	virtual Ref handlePairingCompleteRef(const Peer &) override final;
+	virtual void handlePairingResult(Context &) override final;
+};
+
+template<class Result>
+Ref PairingService<Result>::handlePairingCompleteRef(const Peer & peer)
+{
+	return handlePairingComplete(peer).ref();
+}
+
+template<class Result>
+void PairingService<Result>::handlePairingResult(Context & ctx)
+{
+	handlePairingResult(ctx, Stored<Result>::load(ctx.ref()));
+}
+
+}