diff -r 2b1666bc1b45 -r 3077e2489dfe src/sync.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/sync.c	Tue May 03 15:50:40 2016 +0200
@@ -0,0 +1,29 @@
+#include "pEp_internal.h"
+#include "sync_internal.h"
+
+#include <memory.h>
+#include <assert.h>
+
+
+PEP_sync_callbacks_t PEP_sync_callbacks = { NULL, NULL, NULL };
+
+DYNAMIC_API PEP_STATUS register_sync_callbacks(
+        PEP_SESSION session,
+        sendBeacon_t sendBeacon,
+        sendHandshakeRequest_t sendHandshakeRequest,
+        showHandshake_t showHandshake
+    )
+{
+    PEP_sync_callbacks.sendBeacon = sendBeacon;
+    PEP_sync_callbacks.sendHandshakeRequest = sendHandshakeRequest;
+    PEP_sync_callbacks.showHandshake = showHandshake;
+
+    return PEP_STATUS_OK;
+}
+
+DYNAMIC_API void unregister_sync_callbacks(PEP_SESSION session) {
+    PEP_sync_callbacks.sendBeacon = NULL;
+    PEP_sync_callbacks.sendHandshakeRequest = NULL;
+    PEP_sync_callbacks.showHandshake = NULL;
+}
+