Add method to check whether cross-signing has keys

src/client.js

@@ -964,6 +964,14 @@ function wrapCryptoFuncs(MatrixClient, names) {
     }
 }
 
+/**
+ * Check whether we already have cross-signing keys for the current user.
+ * The cross-signing API is currently UNSTABLE and may change without notice.
+ *
+ * @function module:client~MatrixClient#doesCrossSigningHaveKeys
+ * @return {boolean} Whether we have keys.
+ */
+
  /**
  * Generate new cross-signing keys.
  * The cross-signing API is currently UNSTABLE and may change without notice.
@@ -1018,6 +1026,7 @@ function wrapCryptoFuncs(MatrixClient, names) {
  */
 
 wrapCryptoFuncs(MatrixClient, [
+    "doesCrossSigningHaveKeys",
     "resetCrossSigningKeys",
     "getCrossSigningId",
     "getStoredCrossSigningForUser",

src/crypto/CrossSigning.js

@@ -101,6 +101,10 @@ export class CrossSigningInfo extends EventEmitter {
         };
     }
 
+    hasKeys() {
+        return Object.keys(this.keys).length > 0;
+    }
+
     /**
      * Get the ID used to identify the user
      *

src/crypto/index.js

@@ -328,6 +328,15 @@ Crypto.prototype.checkPrivateKey = function(privateKey, expectedPublicKey) {
     }
 };
 
+/**
+ * Check whether we already have cross-signing keys for the current user.
+ *
+ * @return {boolean} Whether we have keys.
+ */
+Crypto.prototype.doesCrossSigningHaveKeys = function() {
+    return this._crossSigningInfo.hasKeys();
+};
+
 /**
  * Generate new cross-signing keys.
  *