FIDO U2F component extension

chrome/browser/resources/cryptotoken/usbsignhelper.js

Index: chrome/browser/resources/cryptotoken/usbsignhelper.js
diff --git a/chrome/browser/resources/cryptotoken/usbsignhelper.js b/chrome/browser/resources/cryptotoken/usbsignhelper.js
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+// Copyright (c) 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+/**
+ * @fileoverview Implements a sign helper using USB gnubbies.
+ * @author juanlang@google.com (Juan Lang)
+ */
+'use strict';
+
+var CORRUPT_sign = false;
+
+/**
+ * @param {!GnubbyFactory} factory
+ * @param {Countdown} timer Timer after whose expiration the caller is no longer
+ *     interested in the result of a sign request.
+ * @param {function(number, boolean)} errorCb Called when a sign request fails
+ *     with an error code and whether any gnubbies were found.
+ * @param {function(SignHelperChallenge, string)} successCb Called with the
+ *     signature produced by a successful sign request.
+ * @param {(function(number, boolean)|undefined)} opt_progressCb Called with
+ *     progress updates to the sign request.
+ * @param {string=} opt_logMsgUrl A URL to post log messages to.
+ * @constructor
+ * @implements {SignHelper}
+ */
+function UsbSignHelper(factory, timer, errorCb, successCb, opt_progressCb,
+    opt_logMsgUrl) {
+  /** @private {!GnubbyFactory} */
+  this.factory_ = factory;
+  /** @private {Countdown} */
+  this.timer_ = timer;
+  /** @private {function(number, boolean)} */
+  this.errorCb_ = errorCb;
+  /** @private {function(SignHelperChallenge, string)} */
+  this.successCb_ = successCb;
+  /** @private {string|undefined} */
+  this.logMsgUrl_ = opt_logMsgUrl;
+
+  /** @private {Array.<SignHelperChallenge>} */
+  this.pendingChallenges_ = [];
+  /** @private {Array.<usbGnubby>} */
+  this.waitingForTouchGnubbies_ = [];
+
+  /** @private {boolean} */
+  this.notified_ = false;
+  /** @private {boolean} */
+  this.signerComplete_ = false;
+}
+
+/**
+ * Attempts to sign the provided challenges.
+ * @param {Array.<SignHelperChallenge>} challenges
+ * @return {boolean} whether this set of challenges was accepted.
+ */
+UsbSignHelper.prototype.doSign = function(challenges) {
+  if (!challenges.length) {
+    // Fail a sign request with an empty set of challenges, and pretend to have
+    // alerted the caller in case the enumerate is still pending.
+    this.notified_ = true;
+    return false;
+  } else {
+    this.pendingChallenges_ = challenges;
+    this.getSomeGnubbies_();
+    return true;
+  }
+};
+
+/**
+ * Enumerates gnubbies, and begins processing challenges upon enumeration if
+ * any gnubbies are found.
+ * @private
+ */
+UsbSignHelper.prototype.getSomeGnubbies_ = function() {
+  this.factory_.enumerate(this.enumerateCallback.bind(this));
+};
+
+/**
+ * Called with the result of enumerating gnubbies.
+ * @param {number} rc the result of the enumerate.
+ * @param {Array.<llGnubbyDeviceId>} indexes
+ */
+UsbSignHelper.prototype.enumerateCallback = function(rc, indexes) {
+  if (rc) {
+    this.notifyError_(rc, false);
+    return;
+  }
+  if (!indexes.length) {
+    this.notifyError_(DeviceStatusCodes.WRONG_DATA_STATUS, false);
+    return;
+  }
+  if (this.timer_.expired()) {
+    this.notifyError_(DeviceStatusCodes.TIMEOUT_STATUS, true);
+    return;
+  }
+  this.gotSomeGnubbies_(indexes);
+};
+
+/**
+ * Called with the result of enumerating gnubby indexes.
+ * @param {Array.<llGnubbyDeviceId>} indexes
+ * @private
+ */
+UsbSignHelper.prototype.gotSomeGnubbies_ = function(indexes) {
+  /** @private {MultipleGnubbySigner} */
+  this.signer_ = new MultipleGnubbySigner(
+      this.factory_,
+      indexes,
+      false /* forEnroll */,
+      this.signerCompleted_.bind(this),
+      this.signerFoundGnubby_.bind(this),
+      this.timer_,
+      this.logMsgUrl_);
+  this.signer_.addEncodedChallenges(this.pendingChallenges_, true);
+};
+
+/**
+ * Called when a MultipleGnubbySigner completes its sign request.
+ * @param {boolean} anySucceeded whether any sign attempt completed
+ *     successfully.
+ * @param {number=} errorCode an error code from a failing gnubby, if one was
+ *     found.
+ * @private
+ */
+UsbSignHelper.prototype.signerCompleted_ = function(anySucceeded, errorCode) {
+  this.signerComplete_ = true;
+  // The signer is not created unless some gnubbies were enumerated, so
+  // anyGnubbies is mostly always true. The exception is when the last gnubby is
+  // removed, handled shortly.
+  var anyGnubbies = true;
+  if (!anySucceeded) {
+    if (!errorCode) {
+      errorCode = DeviceStatusCodes.WRONG_DATA_STATUS;
+    } else if (errorCode == -llGnubby.GONE) {
+      // If the last gnubby was removed, report as though no gnubbies were
+      // found.
+      errorCode = DeviceStatusCodes.WRONG_DATA_STATUS;
+      anyGnubbies = false;
+    }
+    this.notifyError_(errorCode, anyGnubbies);
+  } else if (this.anyTimeout_) {
+    // Some previously succeeding gnubby timed out: return its error code.
+    this.notifyError_(this.timeoutError_, anyGnubbies);
+  } else {
+    // Do nothing: signerFoundGnubby_ will have been called with each
+    // succeeding gnubby.
+  }
+};
+
+/**
+ * Called when a MultipleGnubbySigner finds a gnubby that has successfully
+ * signed, or can successfully sign, one of the challenges.
+ * @param {number} code
+ * @param {MultipleSignerResult} signResult
+ * @private
+ */
+UsbSignHelper.prototype.signerFoundGnubby_ = function(code, signResult) {
+  var gnubby = signResult['gnubby'];
+  var challenge = signResult['challenge'];
+  var info = new Uint8Array(signResult['info']);
+  if (code == DeviceStatusCodes.OK_STATUS && info.length > 0 && info[0]) {
+    this.notifySuccess_(gnubby, challenge, info);
+  } else {
+    this.waitingForTouchGnubbies_.push(gnubby);
+    this.retrySignIfNotTimedOut_(gnubby, challenge, code);
+  }
+};
+
+/**
+ * Reports the result of a successful sign operation.
+ * @param {usbGnubby} gnubby
+ * @param {SignHelperChallenge} challenge
+ * @param {Uint8Array} info
+ * @private
+ */
+UsbSignHelper.prototype.notifySuccess_ = function(gnubby, challenge, info) {
+  if (this.notified_)
+    return;
+  this.notified_ = true;
+
+  gnubby.closeWhenIdle();
+  this.close();
+
+  if (CORRUPT_sign) {
+    CORRUPT_sign = false;
+    info[info.length - 1] = info[info.length - 1] ^ 0xff;
+  }
+  var encodedChallenge = {};
+  encodedChallenge['challengeHash'] = B64_encode(challenge['challengeHash']);
+  encodedChallenge['appIdHash'] = B64_encode(challenge['appIdHash']);
+  encodedChallenge['keyHandle'] = B64_encode(challenge['keyHandle']);
+  this.successCb_(
+      /** @type {SignHelperChallenge} */ (encodedChallenge), B64_encode(info));
+};
+
+/**
+ * Reports error to the caller.
+ * @param {number} code error to report
+ * @param {boolean} anyGnubbies
+ * @private
+ */
+UsbSignHelper.prototype.notifyError_ = function(code, anyGnubbies) {
+  if (this.notified_)
+    return;
+  this.notified_ = true;
+  this.close();
+  this.errorCb_(code, anyGnubbies);
+};
+
+/**
+ * Retries signing a particular challenge on a gnubby.
+ * @param {usbGnubby} gnubby
+ * @param {SignHelperChallenge} challenge
+ * @private
+ */
+UsbSignHelper.prototype.retrySign_ = function(gnubby, challenge) {
+  var challengeHash = challenge['challengeHash'];
+  var appIdHash = challenge['appIdHash'];
+  var keyHandle = challenge['keyHandle'];
+  gnubby.sign(challengeHash, appIdHash, keyHandle,
+      this.signCallback_.bind(this, gnubby, challenge));
+};
+
+/**
+ * Called when a gnubby completes a sign request.
+ * @param {usbGnubby} gnubby
+ * @param {SignHelperChallenge} challenge
+ * @param {number} code
+ * @private
+ */
+UsbSignHelper.prototype.retrySignIfNotTimedOut_ =
+    function(gnubby, challenge, code) {
+  if (this.timer_.expired()) {
+    // Store any timeout error code, to be returned from the complete
+    // callback if no other eligible gnubbies are found.
+    /** @private {boolean} */
+    this.anyTimeout_ = true;
+    /** @private {number} */
+    this.timeoutError_ = code;
+    this.removePreviouslyEligibleGnubby_(gnubby, code);
+  } else {
+    window.setTimeout(this.retrySign_.bind(this, gnubby, challenge), 200);
+  }
+};
+
+/**
+ * Removes a gnubby that was waiting for touch from the list, with the given
+ * error code. If this is the last gnubby, notifies the caller of the error.
+ * @param {usbGnubby} gnubby
+ * @param {number} code
+ * @private
+ */
+UsbSignHelper.prototype.removePreviouslyEligibleGnubby_ =
+    function(gnubby, code) {
+  // Close this gnubby.
+  gnubby.closeWhenIdle();
+  var index = this.waitingForTouchGnubbies_.indexOf(gnubby);
+  if (index >= 0) {
+    this.waitingForTouchGnubbies_.splice(index, 1);
+  }
+  if (!this.waitingForTouchGnubbies_.length && this.signerComplete_ &&
+      !this.notified_) {
+    // Last sign attempt is complete: return this error.
+    console.log(UTIL_fmt('timeout or error (' + code.toString(16) +
+        ') signing'));
+    // If the last device is gone, report as if no gnubbies were found.
+    if (code == -llGnubby.GONE) {
+      this.notifyError_(DeviceStatusCodes.WRONG_DATA_STATUS, false);
+      return;
+    }
+    this.notifyError_(code, true);
+  }
+};
+
+/**
+ * Called when a gnubby completes a sign request.
+ * @param {usbGnubby} gnubby
+ * @param {SignHelperChallenge} challenge
+ * @param {number} code
+ * @param {ArrayBuffer=} infoArray
+ * @private
+ */
+UsbSignHelper.prototype.signCallback_ =
+    function(gnubby, challenge, code, infoArray) {
+  if (this.notified_) {
+    // Individual sign completed after previous success or failure. Disregard.
+    return;
+  }
+  var info = new Uint8Array(infoArray || []);
+  if (code == DeviceStatusCodes.OK_STATUS && info.length > 0 && info[0]) {
+    this.notifySuccess_(gnubby, challenge, info);
+  } else if (code == DeviceStatusCodes.OK_STATUS ||
+      code == DeviceStatusCodes.WAIT_TOUCH_STATUS ||
+      code == DeviceStatusCodes.BUSY_STATUS) {
+    this.retrySignIfNotTimedOut_(gnubby, challenge, code);
+  } else {
+    console.log(UTIL_fmt('got error ' + code.toString(16) + ' signing'));
+    this.removePreviouslyEligibleGnubby_(gnubby, code);
+  }
+};
+
+/**
+ * Closes the MultipleGnubbySigner, if any.
+ */
+UsbSignHelper.prototype.close = function() {
+  if (this.signer_) {
+    this.signer_.close();
+    this.signer_ = null;
+  }
+  for (var i = 0; i < this.waitingForTouchGnubbies_.length; i++) {
+    this.waitingForTouchGnubbies_[i].closeWhenIdle();
+  }
+  this.waitingForTouchGnubbies_ = [];
+};
+
+/**
+ * @param {!GnubbyFactory} gnubbyFactory Factory to create gnubbies.
+ * @constructor
+ * @implements {SignHelperFactory}
+ */
+function UsbSignHelperFactory(gnubbyFactory) {
+  /** @private {!GnubbyFactory} */
+  this.gnubbyFactory_ = gnubbyFactory;
+}
+
+/**
+ * @param {Countdown} timer Timer after whose expiration the caller is no longer
+ *     interested in the result of a sign request.
+ * @param {function(number, boolean)} errorCb Called when a sign request fails
+ *     with an error code and whether any gnubbies were found.
+ * @param {function(SignHelperChallenge, string)} successCb Called with the
+ *     signature produced by a successful sign request.
+ * @param {(function(number, boolean)|undefined)} opt_progressCb Called with
+ *     progress updates to the sign request.
+ * @param {string=} opt_logMsgUrl A URL to post log messages to.
+ * @return {UsbSignHelper} the newly created helper.
+ */
+UsbSignHelperFactory.prototype.createHelper =
+    function(timer, errorCb, successCb, opt_progressCb, opt_logMsgUrl) {
+  var helper =
+      new UsbSignHelper(this.gnubbyFactory_, timer, errorCb, successCb,
+          opt_progressCb, opt_logMsgUrl);
+  return helper;
+};