Use to-device events for key sharing

Synapse now supports out-of-band messages, so use them instead of sending the
key-sharing messages in-band.

lib/base-apis.js

@@ -66,8 +66,9 @@ function MatrixBaseApis(opts) {
         extraParams: opts.queryParams
     };
     this._http = new httpApi.MatrixHttpApi(this, httpOpts);
-}
 
+    this._txnCtr = 0;
+}
 
 /**
  * Get the Homeserver URL of this client
@@ -100,6 +101,15 @@ MatrixBaseApis.prototype.isLoggedIn = function() {
     return this._http.opts.accessToken !== undefined;
 };
 
+/**
+ * Make up a new transaction id
+ *
+ * @return {string} a new, unique, transaction id
+ */
+MatrixBaseApis.prototype.makeTxnId = function() {
+    return "m" + new Date().getTime() + "." + (this._txnCtr++);
+};
+
 
 // Registration/Login operations
 // =============================
@@ -970,6 +980,39 @@ MatrixBaseApis.prototype.lookupThreePid = function(medium, address, callback) {
     );
 };
 
+
+// Direct-to-device messaging
+// ==========================
+
+/**
+ * Send an event to a specific list of devices
+ *
+ * @param {string} eventType  type of event to send
+ * @param {Object.<string, Object<string, Object>>} contentMap
+ *    content to send. Map from user_id to device_id to content object.
+ * @param {string=} txnId     transaction id. One will be made up if not
+ *    supplied.
+ * @return {module:client.Promise} Resolves to the result object
+ */
+MatrixBaseApis.prototype.sendToDevice = function(
+    eventType, contentMap, txnId
+) {
+    var path = utils.encodeUri("/sendToDevice/$eventType/$txnId", {
+        $eventType: eventType,
+        $txnId: txnId ? txnId : this.makeTxnId(),
+    });
+
+    var body = {
+        messages: contentMap,
+    };
+
+    return this._http.authedRequestWithPrefix(
+        undefined, "PUT", path, undefined, body,
+        httpApi.PREFIX_UNSTABLE
+    );
+};
+
+
 /**
  * MatrixBaseApis object
  */