3 files changed, 18 insertions, 18 deletions
diff --git a/app/assets/javascripts/u2f/authenticate.js.coffee b/app/assets/javascripts/u2f/authenticate.js.coffee
index 6deb902c8de..918c0a560fd 100644
--- a/app/assets/javascripts/u2f/authenticate.js.coffee
+++ b/app/assets/javascripts/u2f/authenticate.js.coffee
@@ -6,8 +6,20 @@
 class @U2FAuthenticate
   constructor: (@container, u2fParams) ->
     @appId = u2fParams.app_id
-    @challenges = u2fParams.challenges
-    @signRequests = u2fParams.sign_requests
+    @challenge = u2fParams.challenge
+
+    # The U2F Javascript API v1.1 requires a single challenge, with
+    # _no challenges per-request_. The U2F Javascript API v1.0 requires a
+    # challenge per-request, which is done by copying the single challenge
+    # into every request.
+    #
+    # In either case, we don't need the per-request challenges that the server
+    # has generated, so we can remove them.
+    #
+    # Note: The server library fixes this behaviour in (unreleased) version 1.0.0.
+    # This can be removed once we upgrade.
+    # https://github.com/castle/ruby-u2f/commit/103f428071a81cd3d5f80c2e77d522d5029946a4
+    @signRequests = u2fParams.sign_requests.map (request) -> _(request).omit('challenge')
 
   start: () =>
     if U2FUtil.isU2FSupported()
@@ -16,7 +28,7 @@ class @U2FAuthenticate
       @renderNotSupported()
 
   authenticate: () =>
-    u2f.sign(@appId, @challenges, @signRequests, (response) =>
+    u2f.sign(@appId, @challenge, @signRequests, (response) =>
       if response.errorCode
         error = new U2FError(response.errorCode)
         @renderError(error);
diff --git a/app/assets/javascripts/u2f/util.js.coffee b/app/assets/javascripts/u2f/util.js.coffee
new file mode 100644
index 00000000000..5ef324f609d
--- /dev/null
+++ b/app/assets/javascripts/u2f/util.js.coffee
@@ -0,0 +1,3 @@
+class @U2FUtil
+  @isU2FSupported: ->
+    window.u2f
diff --git a/app/assets/javascripts/u2f/util.js.coffee.erb b/app/assets/javascripts/u2f/util.js.coffee.erb
deleted file mode 100644
index d59341c38b9..00000000000
--- a/app/assets/javascripts/u2f/util.js.coffee.erb
+++ /dev/null
@@ -1,15 +0,0 @@
-# Helper class for U2F (universal 2nd factor) device registration and authentication.
-
-class @U2FUtil
-  @isU2FSupported: ->
-    if @testMode
-      true
-    else
-      gon.u2f.browser_supports_u2f
-
-  @enableTestMode: ->
-    @testMode = true
-
-<% if Rails.env.test? %>
-U2FUtil.enableTestMode();
-<% end %>