Index: build/chrome/cackey.js
==================================================================
--- build/chrome/cackey.js
+++ build/chrome/cackey.js
@@ -6,10 +6,17 @@
 	// If certificates were rejected by the API, log an error, for example.
 	console.error(rejectedCerts.length + ' certificates were rejected.');
 	return;
 }
 
+/*
+ * Optional features for CACKey
+ */
+var cackeyFeatures = {
+	customPINPrompt: true
+};
+
 /*
  * Handle for the CACKey NaCl Target
  */
 var cackeyHandle = null;
 var cackeyPCSCHandle = null;
@@ -340,11 +347,11 @@
 	
 						return;
 					}
 	
 					pinWindowPreviousHandle = pinWindow;
-	
+
 					pinWindow.drawAttention();
 					pinWindow.focus();
 	
 					/*
 					 * Register a handler to handle the window being closed without
@@ -371,31 +378,40 @@
 					/*
 					 * Pass this message off to the other window so that it may resubmit the request.
 					 */
 					pinWindow.contentWindow.parentWindow = window;
 					pinWindow.contentWindow.messageEvent = messageEvent;
+
+					if (cackeyFeatures.customPINPrompt) {
+						pinWindow.contentWindow.pinprompt = messageEvent.data.pinprompt;
+					}
 	
 					return;
 				});
 			} else {
 				chrome.certificateProvider.requestPin({
 					signRequestId: messageEvent.data.originalrequest.signRequestId,
 					requestType: "PIN"
 				}, function(userInfo) {
-					chrome.certificateProvider.stopPinRequest({
-						signRequestId: messageEvent.data.originalrequest.signRequestId
-					}, function() {
-						var pinValue = "";
-
-						pinWindowPreviousHandle = null;
-
-						if (userInfo && userInfo.userInput) {
-							pinValue = userInfo.userInput;
-						}
-
-						return(cackeyPINPromptCompleted(pinValue));
-					});
+					var destroyError;
+					var pinValue = "";
+
+					try {
+						chrome.certificateProvider.stopPinRequest({
+							signRequestId: messageEvent.data.originalrequest.signRequestId
+						}, function() {});
+					} catch (destroyError) {
+						/* Do nothing, we don't care if it fails really */
+					}
+
+					pinWindowPreviousHandle = null;
+
+					if (userInfo && userInfo.userInput) {
+						pinValue = userInfo.userInput;
+					}
+
+					return(cackeyPINPromptCompleted(pinValue));
 				});
 			}
 
 			/*
 			 * We return here instead of break to avoid deleting the callback