resources/js/u2f.js
// Copyright 2014 Google Inc. All rights reserved
//
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file or at
// https://developers.google.com/open-source/licenses/bsd
/**
* @fileoverview The U2F api.
*/
'use strict';
/** Namespace for the U2F api.
* @type {Object}
*/
var u2f = u2f || {};
/**
* The U2F extension id
* @type {string}
* @const
*/
u2f.EXTENSION_ID = 'kmendfapggjehodndflmmgagdbamhnfd';
/**
* Message types for messsages to/from the extension
* @const
* @enum {string}
*/
u2f.MessageTypes = {
'U2F_REGISTER_REQUEST': 'u2f_register_request',
'U2F_SIGN_REQUEST': 'u2f_sign_request',
'U2F_REGISTER_RESPONSE': 'u2f_register_response',
'U2F_SIGN_RESPONSE': 'u2f_sign_response'
};
/**
* Response status codes
* @const
* @enum {number}
*/
u2f.ErrorCodes = {
'OK': 0,
'OTHER_ERROR': 1,
'BAD_REQUEST': 2,
'CONFIGURATION_UNSUPPORTED': 3,
'DEVICE_INELIGIBLE': 4,
'TIMEOUT': 5
};
/**
* A message type for registration requests
* @typedef {{
* type: u2f.MessageTypes,
* signRequests: Array.<u2f.SignRequest>,
* registerRequests: ?Array.<u2f.RegisterRequest>,
* timeoutSeconds: ?number,
* requestId: ?number
* }}
*/
u2f.Request;
/**
* A message for registration responses
* @typedef {{
* type: u2f.MessageTypes,
* responseData: (u2f.Error | u2f.RegisterResponse | u2f.SignResponse),
* requestId: ?number
* }}
*/
u2f.Response;
/**
* An error object for responses
* @typedef {{
* errorCode: u2f.ErrorCodes,
* errorMessage: ?string
* }}
*/
u2f.Error;
/**
* Data object for a single sign request.
* @typedef {{
* version: string,
* challenge: string,
* keyHandle: string,
* appId: string
* }}
*/
u2f.SignRequest;
/**
* Data object for a sign response.
* @typedef {{
* keyHandle: string,
* signatureData: string,
* clientData: string
* }}
*/
u2f.SignResponse;
/**
* Data object for a registration request.
* @typedef {{
* version: string,
* challenge: string,
* appId: string
* }}
*/
u2f.RegisterRequest;
/**
* Data object for a registration response.
* @typedef {{
* registrationData: string,
* clientData: string
* }}
*/
u2f.RegisterResponse;
// Low level MessagePort API support
/**
* Sets up a MessagePort to the U2F extension using the
* available mechanisms.
* @param {function((MessagePort|u2f.WrappedChromeRuntimePort_))} callback
*/
u2f.getMessagePort = function(callback) {
if (typeof chrome != 'undefined' && chrome.runtime) {
// The actual message here does not matter, but we need to get a reply
// for the callback to run. Thus, send an empty signature request
// in order to get a failure response.
var msg = {
type: u2f.MessageTypes.U2F_SIGN_REQUEST,
signRequests: []
};
chrome.runtime.sendMessage(u2f.EXTENSION_ID, msg, function() {
if (!chrome.runtime.lastError) {
// We are on a whitelisted origin and can talk directly
// with the extension.
u2f.getChromeRuntimePort_(callback);
} else {
// chrome.runtime was available, but we couldn't message
// the extension directly, use iframe
u2f.getIframePort_(callback);
}
});
} else {
// chrome.runtime was not available at all, which is normal
// when this origin doesn't have access to any extensions.
u2f.getIframePort_(callback);
}
};
/**
* Connects directly to the extension via chrome.runtime.connect
* @param {function(u2f.WrappedChromeRuntimePort_)} callback
* @private
*/
u2f.getChromeRuntimePort_ = function(callback) {
var port = chrome.runtime.connect(u2f.EXTENSION_ID, {
'includeTlsChannelId': true
});
setTimeout(function() {
callback(new u2f.WrappedChromeRuntimePort_(port));
}, 0);
};
/**
* A wrapper for chrome.runtime.Port that is compatible with MessagePort.
* @param {Port} port
* @constructor
* @private
*/
u2f.WrappedChromeRuntimePort_ = function(port) {
this.port_ = port;
};
/**
* Posts a message on the underlying channel.
* @param {Object} message
*/
u2f.WrappedChromeRuntimePort_.prototype.postMessage = function(message) {
this.port_.postMessage(message);
};
/**
* Emulates the HTML 5 addEventListener interface. Works only for the
* onmessage event, which is hooked up to the chrome.runtime.Port.onMessage.
* @param {string} eventName
* @param {function({data: Object})} handler
*/
u2f.WrappedChromeRuntimePort_.prototype.addEventListener = function(eventName, handler) {
var name = eventName.toLowerCase();
if (name == 'message' || name == 'onmessage') {
this.port_.onMessage.addListener(function(message) {
// Emulate a minimal MessageEvent object
handler({
'data': message
});
});
} else {
console.error('WrappedChromeRuntimePort only supports onMessage');
}
};
/**
* Sets up an embedded trampoline iframe, sourced from the extension.
* @param {function(MessagePort)} callback
* @private
*/
u2f.getIframePort_ = function(callback) {
// Create the iframe
var iframeOrigin = 'chrome-extension://' + u2f.EXTENSION_ID;
var iframe = document.createElement('iframe');
iframe.src = iframeOrigin + '/u2f-comms.html';
iframe.setAttribute('style', 'display:none');
document.body.appendChild(iframe);
var channel = new MessageChannel();
var ready = function(message) {
if (message.data == 'ready') {
channel.port1.removeEventListener('message', ready);
callback(channel.port1);
} else {
console.error('First event on iframe port was not "ready"');
}
};
channel.port1.addEventListener('message', ready);
channel.port1.start();
iframe.addEventListener('load', function() {
// Deliver the port to the iframe and initialize
iframe.contentWindow.postMessage('init', iframeOrigin, [channel.port2]);
});
};
// High-level JS API
/**
* Default extension response timeout in seconds.
* @const
*/
u2f.EXTENSION_TIMEOUT_SEC = 30;
/**
* A singleton instance for a MessagePort to the extension.
* @type {MessagePort|u2f.WrappedChromeRuntimePort_}
* @private
*/
u2f.port_ = null;
/**
* Callbacks waiting for a port
* @type {Array.<function((MessagePort|u2f.WrappedChromeRuntimePort_))>}
* @private
*/
u2f.waitingForPort_ = [];
/**
* A counter for requestIds.
* @type {number}
* @private
*/
u2f.reqCounter_ = 0;
/**
* A map from requestIds to client callbacks
* @type {Object.<number,(function((u2f.Error|u2f.RegisterResponse))
* |function((u2f.Error|u2f.SignResponse)))>}
* @private
*/
u2f.callbackMap_ = {};
/**
* Creates or retrieves the MessagePort singleton to use.
* @param {function((MessagePort|u2f.WrappedChromeRuntimePort_))} callback
* @private
*/
u2f.getPortSingleton_ = function(callback) {
if (u2f.port_) {
callback(u2f.port_);
} else {
if (u2f.waitingForPort_.length == 0) {
u2f.getMessagePort(function(port) {
u2f.port_ = port;
u2f.port_.addEventListener('message',
/** @type {function(Event)} */
(u2f.responseHandler_));
// Careful, here be async callbacks. Maybe.
while (u2f.waitingForPort_.length)
u2f.waitingForPort_.shift()(u2f.port_);
});
}
u2f.waitingForPort_.push(callback);
}
};
/**
* Handles response messages from the extension.
* @param {MessageEvent.<u2f.Response>} message
* @private
*/
u2f.responseHandler_ = function(message) {
var response = message.data;
var reqId = response['requestId'];
if (!reqId || !u2f.callbackMap_[reqId]) {
console.error('Unknown or missing requestId in response.');
return;
}
var cb = u2f.callbackMap_[reqId];
delete u2f.callbackMap_[reqId];
cb(response['responseData']);
};
/**
* Dispatches an array of sign requests to available U2F tokens.
* @param {Array.<u2f.SignRequest>} signRequests
* @param {function((u2f.Error|u2f.SignResponse))} callback
* @param {number=} opt_timeoutSeconds
*/
u2f.sign = function(signRequests, callback, opt_timeoutSeconds) {
u2f.getPortSingleton_(function(port) {
var reqId = ++u2f.reqCounter_;
u2f.callbackMap_[reqId] = callback;
var req = {
type: u2f.MessageTypes.U2F_SIGN_REQUEST,
signRequests: signRequests,
timeoutSeconds: (typeof opt_timeoutSeconds !== 'undefined' ? opt_timeoutSeconds : u2f.EXTENSION_TIMEOUT_SEC),
requestId: reqId
};
port.postMessage(req);
});
};
/**
* Dispatches register requests to available U2F tokens. An array of sign
* requests identifies already registered tokens.
* @param {Array.<u2f.RegisterRequest>} registerRequests
* @param {Array.<u2f.SignRequest>} signRequests
* @param {function((u2f.Error|u2f.RegisterResponse))} callback
* @param {number=} opt_timeoutSeconds
*/
u2f.register = function(registerRequests, signRequests,
callback, opt_timeoutSeconds) {
u2f.getPortSingleton_(function(port) {
var reqId = ++u2f.reqCounter_;
u2f.callbackMap_[reqId] = callback;
var req = {
type: u2f.MessageTypes.U2F_REGISTER_REQUEST,
signRequests: signRequests,
registerRequests: registerRequests,
timeoutSeconds: (typeof opt_timeoutSeconds !== 'undefined' ? opt_timeoutSeconds : u2f.EXTENSION_TIMEOUT_SEC),
requestId: reqId
};
port.postMessage(req);
});
};