Merge branch '15337-yubikey-support' into 'master'

Allow a U2F Device to be the Second Factor for Authentication

Parent Issue: #15337 

## TODO
- [ ] #15337 (!3905) FIDO/U2F 2FA using Yubikey
    - [x] Order a Yubikey?
    - [x] Do some reading to figure out what all this stuff means
    - [x] Look through the existing MR
    - [x] Browser support?
    - [x] Implementation
        - [x] User can register 2FA using their U2H device instead of authenticator
            - [x] Barebones flow
            - [x] Save the registration in the database
            - [x] Authentication flow
            - [x] First try after login/server start doesn't work
        - [x] User can log in using their U2F device
        - [x] Allow setting up authenticator if U2F is already set up (or vice versa)
        - [x] Change `two_factor_auths/new` to `show`
        - [x] `sign_requests` during registration? (Registering a device that has already been registered)
        - [x] 2FA skippable flow?
        - [x] Enforced 2FA flow (grace period?)
        - [x] Move the "Configure it Later" button to the right place
        - [x] Don't allow registration when the yubikey isn't plugged in
        - [x] Polish authentication flow
        - [x] Login should only show the 2FA method that's enabled
            - [x] Message to say that u2f only works on chrome, and it's recommended to enable otp as well.
        - [x] Index for key_handle
        - [x] Server-side errors while registering/logging in
        - [x] Handle non-chrome browsers
        - [x] Try to authenticate with a key that hasn't been registered (shouldn't work)
        - [x] Try the same key for multiple user accounts (should work)
        - [x] Fix existing tests
        - [x] Make sure CI is green
        - [x] Add tests
            - [x] Figure out how to fake the Yubikey
            - [x] Teaspoon tests for the React components
                - [x] Each device can only be registered once per user
            - [x] Feature specs
                - [x] Regular flows
                - [x] Test error cases
        - [x] Refactoring
            - [x] Refactor App ID
            - [x] Clean up the `show` action
        - [x] Annotate methods with definition of U2F
        - [x] Changelog
        - [x] Fix merge conflicts
        - [x] Verify flows
            - [x] Authenticator + no U2F
            - [x] U2F + no authenticator
            - [x] U2F + authenticator
            - [x] U2F + authenticator -> disable 2FA
            - [x] 2FA required with different grace periods
        - [x] Screenshots for MR
    - [x] Augment the [help docs](http://localhost:3000/help/profile/two_factor_authentication)
    - [x] Assign to endboss
    - [x] Ask for feedback on UI/UX
    - [x] Ask for feedback on copy
    - [x] Wait for review/merge
    - [x] Fix merge conflicts
    - [x] Wait for CI to pass
    - [x] Implement review comments/suggestions
        - [x] Move `TwoFactorAuthController#create_u2f` to a service
        - [x] Extra space before `Base64` in `u2f_registration` model
        - [x] Move `with/without_two_factor` scopes to class methods
        - [x] In `profiles/accounts/show`, add spaces at `{` and `}`
        - [x] Remove blank lines in `profiles/two_factor_auths/show`
        - [x] Fix typo in doc. "(universal 2nd factor )"
        - [x] Add "Added in 8.8" to doc
        - [x] In the doc, use 'Enable 2FA via mobile application' instead of 'Via Mobile Application'
        - [x] In the doc, use 'Enable 2FA via U2F device' instead of 'Via U2F Device
        - [x] Use "Two-Factor Authentication" everywhere
        - [x] Use `#icon` wrapper instead of `fa_stacked_icon`
        - [x] Check if `string` is enough for `key_handle` and `public_key`
        - [x] Separate `exercise` and `verify` phases of test (u2f_spec)
        - [x] Assert that `user_without_2fa` is _not_ in results (with_two_factor)
            - [x] Remove rubocop exception
        - [x] Refactor call to `User.with_two_factor.count` to not include `.length`
        - [x] Add a note that makes the "Disable" button/feature obvious
        - [x] Remove i18n
        - [x] Test in Firefox with addon (+ create new issue for support)
        - [x] Remove React
            - [x] Rewrite registration
            - [x] Switch underscore template to default style
            - [x] Rewrite authentication
            - [x] Move `register` haml to `u2f` dir
            - [x] Remove instance variables
            - [x] Fix tests
            - [x] Read SCSS guidelines
            - [x] Address @connorshea's comments regarding text style
            - [x] Make sure all classes and IDs are in line (add `js-` prefixes)
                - [x] Register
                - [x] Authenticate
            - [x] Refactoring?
        - [x] Include non-minifed version of bowser
        - [x] Audit log
        - [x] Look at the `browser` gem (and don't use bowser)
        - [x] Error message when on HTTP?
    - [x] Test on Mobile
    - [x] Fix merge conflicts
    - [x] Retest all flows
    - [x] Back to Rémy for review
    - [x] Make sure CI is green
    - [x] Wait for merge / more feedback
    - [x] Implement @rymai's changes
        - [x] JS/Coffeescript variables should be lowerCamelCase
        - [x] Spaces before/after `}` and `{` in HAML (and elsewhere)
        - [x] Rails view helpers in u2f HAML
        - [x] `%div.row.append-bottom-10`
        - [x] Wrap line in `without_two_factor` scope
        - [x] Exception-less flow in `U2F::CreateService`
    - [x] Fix merge conflicts
    - [x] Move service to model class method
    - [x] Fix teaspoon specs
    - [x] Address @rymai's suggestions about error handing
    - [x] Javascript error constants
    - [x] Fix merge conflicts
    - [x] One final review
        - [x] Test "registration with errors" flow
    - [x] Assign to Remy
    - [x] Wait for replies from @jschatz1
    - [x] Address @rymai's comments
        - [x] Omit `%div`
        - [x] Scope `$.find` globally
        - [x] Replace `find('#element-id).click` with `click_on('Element Text')
    - [x] Rebase master + conflicts
    - [x] Look at https://news.ycombinator.com/item?id=11690774
    - [x] Address @connorshea's comment regarding HTTPS on localhost
    - [x] Final sanity check
    - [x] Wait for [CI to pass](https://gitlab.com/gitlab-org/gitlab-ce/commit/c84179ad233529c33ee6ba8491cfea862c6cd864/builds)
    - [x] Address @rymai's next round of comments
        - [x] Interpolate `true` and `false` in DB scopes
        - [x] Why have `Gon::Base.render_data` thrice?
        - [x] `user_spec` should have correct spacing
        - [x] Use `arel_table[:id]` instead of `users.id`
        - [x] URL helper in `app/views/profiles/two_factor_auths/show.html.haml`
        - [x] Remove polyfill change
    - [x] Wait for [CI to pass](https://gitlab.com/gitlab-org/gitlab-ce/commit/0123ab8/builds)
    - [x] Address @jschatz1's comments
        - [x] Use `on('click', ...)` instead of `click(...)`
        - [x] Use `is` and `isnt` in coffeescript
        - [x] Use `and` and `or` in coffeescript
    - [x] Add `Gon::Base.render_data` to `devise_empty` (and other base layouts)
    - [x] Wait for [CI to pass](https://gitlab.com/gitlab-org/gitlab-ce/commit/401916397336174c582be3d3004a072f845d4b5f/builds)
    - [x] Wait for [build](https://gitlab.com/gitlab-org/gitlab-ce/commit/75955710ef9a5f0dcee04e8617028c0e3ea5bf50/builds) to pass
    - [x] Fix merge conflicts
    - [x] Inspect diff / workflow
    - [x] Assign back to @rymai
    - [x] Make sure [ci](https://gitlab.com/gitlab-org/gitlab-ce/commit/2c6316b29a9276ef44c7b4b39363a611bf5973a6/builds) has passed
    - [x] Fix merge conflicts (probably introduced by [devise upgrade](https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/4216)
    - [x] Wait for [CI](https://gitlab.com/gitlab-org/gitlab-ce/commit/a5ef48b7aa63d0d9e45b41643043b57208eaab9f/builds) to pass
    - [x] Respond to @rymai's comments
        - [x] Use `elsif`
        - [x] Check if we need `and return`
        - [x] Only fetch key handles from the DB
        - [x] No annotations to models?
        - [x] Align hash keys in model
    - [x] Wait for [build](https://gitlab.com/gitlab-org/gitlab-ce/commit/e0ef504734e7f14813c73bbb79f5c5f6fae3248c/builds) to pass
    - [ ] Wait for merge

## Screenshots

![Screenshot_2016-05-03_09.53.04](/uploads/1af3f277efa488dc107d36e6b4b07ca4/Screenshot_2016-05-03_09.53.04.png)
![Screenshot_2016-05-03_10.19.53](/uploads/2bfc67dfb96c0e005cce033d8b456813/Screenshot_2016-05-03_10.19.53.png)
![Screenshot_2016-05-03_10.19.56](/uploads/e912abedd5b1d07d7185cee9f204c5ff/Screenshot_2016-05-03_10.19.56.png)
![Screenshot_2016-05-03_10.20.04](/uploads/9350d5c98823d1f3d4e59517dfb8910a/Screenshot_2016-05-03_10.20.04.png)
![Screenshot_2016-05-03_10.31.15](/uploads/84473dc263e0643311a39006e649035f/Screenshot_2016-05-03_10.31.15.png)
![Screenshot_2016-05-03_10.31.22](/uploads/13ce43e0d7a565000af29984667eeb08/Screenshot_2016-05-03_10.31.22.png)
![Screenshot_2016-05-03_10.31.37](/uploads/b90fbb40dbf9bbd73af324f48ffdc948/Screenshot_2016-05-03_10.31.37.png)
![Screenshot_2016-05-03_10.36.48](/uploads/41a0fbc493c6fefeafd922b3ddf2a25e/Screenshot_2016-05-03_10.36.48.png)

See merge request !3905

14 files changed, 532 insertions, 27 deletions

diff --git a/spec/controllers/profiles/two_factor_auths_controller_spec.rb b/spec/controllers/profiles/two_factor_auths_controller_spec.rb
index 4fb1473c2d2..d08d0018b35 100644
--- a/spec/controllers/profiles/two_factor_auths_controller_spec.rb
+++ b/spec/controllers/profiles/two_factor_auths_controller_spec.rb
@@ -8,21 +8,21 @@ describe Profiles::TwoFactorAuthsController do
     allow(subject).to receive(:current_user).and_return(user)
   end
 
-  describe 'GET new' do
+  describe 'GET show' do
     let(:user) { create(:user) }
 
     it 'generates otp_secret for user' do
       expect(User).to receive(:generate_otp_secret).with(32).and_return('secret').once
 
-      get :new
-      get :new # Second hit shouldn't re-generate it
+      get :show
+      get :show # Second hit shouldn't re-generate it
     end
 
     it 'assigns qr_code' do
       code = double('qr code')
       expect(subject).to receive(:build_qr_code).and_return(code)
 
-      get :new
+      get :show
       expect(assigns[:qr_code]).to eq code
     end
   end
@@ -40,7 +40,7 @@ describe Profiles::TwoFactorAuthsController do
         expect(user).to receive(:validate_and_consume_otp!).with(pin).and_return(true)
       end
 
-      it 'sets two_factor_enabled' do
+      it 'enables 2fa for the user' do
         go
 
         user.reload
@@ -79,9 +79,9 @@ describe Profiles::TwoFactorAuthsController do
         expect(assigns[:qr_code]).to eq code
       end
 
-      it 'renders new' do
+      it 'renders show' do
         go
-        expect(response).to render_template(:new)
+        expect(response).to render_template(:show)
       end
     end
   end
diff --git a/spec/controllers/sessions_controller_spec.rb b/spec/controllers/sessions_controller_spec.rb
index 5dc8724fb50..4e9bfb0c69b 100644
--- a/spec/controllers/sessions_controller_spec.rb
+++ b/spec/controllers/sessions_controller_spec.rb
@@ -25,10 +25,15 @@ describe SessionsController do
           expect(response).to set_flash.to /Signed in successfully/
           expect(subject.current_user). to eq user
         end
+
+        it "creates an audit log record" do
+          expect { post(:create, user: { login: user.username, password: user.password }) }.to change { SecurityEvent.count }.by(1)
+          expect(SecurityEvent.last.details[:with]).to eq("standard")
+        end
       end
     end
 
-    context 'when using two-factor authentication' do
+    context 'when using two-factor authentication via OTP' do
       let(:user) { create(:user, :two_factor) }
 
       def authenticate_2fa(user_params)
@@ -117,6 +122,25 @@ describe SessionsController do
           end
         end
       end
+
+      it "creates an audit log record" do
+        expect { authenticate_2fa(login: user.username, otp_attempt: user.current_otp) }.to change { SecurityEvent.count }.by(1)
+        expect(SecurityEvent.last.details[:with]).to eq("two-factor")
+      end
+    end
+
+    context 'when using two-factor authentication via U2F device' do
+      let(:user) { create(:user, :two_factor) }
+
+      def authenticate_2fa_u2f(user_params)
+        post(:create, { user: user_params }, { otp_user_id: user.id })
+      end
+
+      it "creates an audit log record" do
+        allow(U2fRegistration).to receive(:authenticate).and_return(true)
+        expect { authenticate_2fa_u2f(login: user.username, device_response: "{}") }.to change { SecurityEvent.count }.by(1)
+        expect(SecurityEvent.last.details[:with]).to eq("two-factor-via-u2f-device")
+      end
     end
   end
 end
diff --git a/spec/factories/u2f_registrations.rb b/spec/factories/u2f_registrations.rb
new file mode 100644
index 00000000000..df92b079581
--- /dev/null
+++ b/spec/factories/u2f_registrations.rb
@@ -0,0 +1,8 @@
+FactoryGirl.define do
+  factory :u2f_registration do
+    certificate { FFaker::BaconIpsum.characters(728) }
+    key_handle { FFaker::BaconIpsum.characters(86) }
+    public_key { FFaker::BaconIpsum.characters(88) }
+    counter 0
+  end
+end
diff --git a/spec/factories/users.rb b/spec/factories/users.rb
index a9b2148bd2a..c6f7869516e 100644
--- a/spec/factories/users.rb
+++ b/spec/factories/users.rb
@@ -15,14 +15,26 @@ FactoryGirl.define do
     end
 
     trait :two_factor do
+      two_factor_via_otp
+    end
+
+    trait :two_factor_via_otp do
       before(:create) do |user|
-        user.two_factor_enabled = true
+        user.otp_required_for_login = true
         user.otp_secret = User.generate_otp_secret(32)
         user.otp_grace_period_started_at = Time.now
         user.generate_otp_backup_codes!
       end
     end
 
+    trait :two_factor_via_u2f do
+      transient { registrations_count 5 }
+
+      after(:create) do |user, evaluator|
+        create_list(:u2f_registration, evaluator.registrations_count, user: user)
+      end
+    end
+
     factory :omniauth_user do
       transient do
         extern_uid '123456'
diff --git a/spec/features/admin/admin_users_spec.rb b/spec/features/admin/admin_users_spec.rb
index 96621843b30..b72ad405479 100644
--- a/spec/features/admin/admin_users_spec.rb
+++ b/spec/features/admin/admin_users_spec.rb
@@ -19,7 +19,7 @@ describe "Admin::Users", feature: true  do
 
     describe 'Two-factor Authentication filters' do
       it 'counts users who have enabled 2FA' do
-        create(:user, two_factor_enabled: true)
+        create(:user, :two_factor)
 
         visit admin_users_path
 
@@ -29,7 +29,7 @@ describe "Admin::Users", feature: true  do
       end
 
       it 'filters by users who have enabled 2FA' do
-        user = create(:user, two_factor_enabled: true)
+        user = create(:user, :two_factor)
 
         visit admin_users_path
         click_link '2FA Enabled'
@@ -38,7 +38,7 @@ describe "Admin::Users", feature: true  do
       end
 
       it 'counts users who have not enabled 2FA' do
-        create(:user, two_factor_enabled: false)
+        create(:user)
 
         visit admin_users_path
 
@@ -48,7 +48,7 @@ describe "Admin::Users", feature: true  do
       end
 
       it 'filters by users who have not enabled 2FA' do
-        user = create(:user, two_factor_enabled: false)
+        user = create(:user)
 
         visit admin_users_path
         click_link '2FA Disabled'
@@ -173,7 +173,7 @@ describe "Admin::Users", feature: true  do
 
     describe 'Two-factor Authentication status' do
       it 'shows when enabled' do
-        @user.update_attribute(:two_factor_enabled, true)
+        @user.update_attribute(:otp_required_for_login, true)
 
         visit admin_user_path(@user)
 
diff --git a/spec/features/login_spec.rb b/spec/features/login_spec.rb
index c1b178c3b6c..72b5ff231f7 100644
--- a/spec/features/login_spec.rb
+++ b/spec/features/login_spec.rb
@@ -33,11 +33,11 @@ feature 'Login', feature: true do
 
       before do
         login_with(user, remember: true)
-        expect(page).to have_content('Two-factor Authentication')
+        expect(page).to have_content('Two-Factor Authentication')
       end
 
       def enter_code(code)
-        fill_in 'Two-factor Authentication code', with: code
+        fill_in 'Two-Factor Authentication code', with: code
         click_button 'Verify code'
       end
 
@@ -143,12 +143,12 @@ feature 'Login', feature: true do
 
       context 'within the grace period' do
         it 'redirects to two-factor configuration page' do
-          expect(current_path).to eq new_profile_two_factor_auth_path
-          expect(page).to have_content('You must enable Two-factor Authentication for your account before')
+          expect(current_path).to eq profile_two_factor_auth_path
+          expect(page).to have_content('You must enable Two-Factor Authentication for your account before')
         end
 
-        it 'disallows skipping two-factor configuration' do
-          expect(current_path).to eq new_profile_two_factor_auth_path
+        it 'allows skipping two-factor configuration', js: true do
+          expect(current_path).to eq profile_two_factor_auth_path
 
           click_link 'Configure it later'
           expect(current_path).to eq root_path
@@ -159,26 +159,26 @@ feature 'Login', feature: true do
         let(:user) { create(:user, otp_grace_period_started_at: 9999.hours.ago) }
 
         it 'redirects to two-factor configuration page' do
-          expect(current_path).to eq new_profile_two_factor_auth_path
-          expect(page).to have_content('You must enable Two-factor Authentication for your account.')
+          expect(current_path).to eq profile_two_factor_auth_path
+          expect(page).to have_content('You must enable Two-Factor Authentication for your account.')
         end
 
-        it 'disallows skipping two-factor configuration' do
-          expect(current_path).to eq new_profile_two_factor_auth_path
+        it 'disallows skipping two-factor configuration', js: true do
+          expect(current_path).to eq profile_two_factor_auth_path
           expect(page).not_to have_link('Configure it later')
         end
       end
     end
 
-    context 'without grace pariod defined' do
+    context 'without grace period defined' do
       before(:each) do
         stub_application_setting(two_factor_grace_period: 0)
         login_with(user)
       end
 
       it 'redirects to two-factor configuration page' do
-        expect(current_path).to eq new_profile_two_factor_auth_path
-        expect(page).to have_content('You must enable Two-factor Authentication for your account.')
+        expect(current_path).to eq profile_two_factor_auth_path
+        expect(page).to have_content('You must enable Two-Factor Authentication for your account.')
       end
     end
   end
diff --git a/spec/features/u2f_spec.rb b/spec/features/u2f_spec.rb
new file mode 100644
index 00000000000..366a90228b1
--- /dev/null
+++ b/spec/features/u2f_spec.rb
@@ -0,0 +1,239 @@
+require 'spec_helper'
+
+feature 'Using U2F (Universal 2nd Factor) Devices for Authentication', feature: true, js: true do
+  def register_u2f_device(u2f_device = nil)
+    u2f_device ||= FakeU2fDevice.new(page)
+    u2f_device.respond_to_u2f_registration
+    click_on 'Setup New U2F Device'
+    expect(page).to have_content('Your device was successfully set up')
+    click_on 'Register U2F Device'
+    u2f_device
+  end
+
+  describe "registration" do
+    let(:user) { create(:user) }
+    before { login_as(user) }
+
+    describe 'when 2FA via OTP is disabled' do
+      it 'allows registering a new device' do
+        visit profile_account_path
+        click_on 'Enable Two-Factor Authentication'
+
+        register_u2f_device
+
+        expect(page.body).to match('Your U2F device was registered')
+      end
+
+      it 'allows registering more than one device' do
+        visit profile_account_path
+
+        # First device
+        click_on 'Enable Two-Factor Authentication'
+        register_u2f_device
+        expect(page.body).to match('Your U2F device was registered')
+
+        # Second device
+        click_on 'Manage Two-Factor Authentication'
+        register_u2f_device
+        expect(page.body).to match('Your U2F device was registered')
+        click_on 'Manage Two-Factor Authentication'
+
+        expect(page.body).to match('You have 2 U2F devices registered')
+      end
+    end
+
+    describe 'when 2FA via OTP is enabled' do
+      before { user.update_attributes(otp_required_for_login: true) }
+
+      it 'allows registering a new device' do
+        visit profile_account_path
+        click_on 'Manage Two-Factor Authentication'
+        expect(page.body).to match("You've already enabled two-factor authentication using mobile")
+
+        register_u2f_device
+
+        expect(page.body).to match('Your U2F device was registered')
+      end
+
+      it 'allows registering more than one device' do
+        visit profile_account_path
+
+        # First device
+        click_on 'Manage Two-Factor Authentication'
+        register_u2f_device
+        expect(page.body).to match('Your U2F device was registered')
+
+        # Second device
+        click_on 'Manage Two-Factor Authentication'
+        register_u2f_device
+        expect(page.body).to match('Your U2F device was registered')
+
+        click_on 'Manage Two-Factor Authentication'
+        expect(page.body).to match('You have 2 U2F devices registered')
+      end
+    end
+
+    it 'allows the same device to be registered for multiple users' do
+      # First user
+      visit profile_account_path
+      click_on 'Enable Two-Factor Authentication'
+      u2f_device = register_u2f_device
+      expect(page.body).to match('Your U2F device was registered')
+      logout
+
+      # Second user
+      login_as(:user)
+      visit profile_account_path
+      click_on 'Enable Two-Factor Authentication'
+      register_u2f_device(u2f_device)
+      expect(page.body).to match('Your U2F device was registered')
+
+      expect(U2fRegistration.count).to eq(2)
+    end
+
+    context "when there are form errors" do
+      it "doesn't register the device if there are errors" do
+        visit profile_account_path
+        click_on 'Enable Two-Factor Authentication'
+
+        # Have the "u2f device" respond with bad data
+        page.execute_script("u2f.register = function(_,_,_,callback) { callback('bad response'); };")
+        click_on 'Setup New U2F Device'
+        expect(page).to have_content('Your device was successfully set up')
+        click_on 'Register U2F Device'
+
+        expect(U2fRegistration.count).to eq(0)
+        expect(page.body).to match("The form contains the following error")
+        expect(page.body).to match("did not send a valid JSON response")
+      end
+
+      it "allows retrying registration" do
+        visit profile_account_path
+        click_on 'Enable Two-Factor Authentication'
+
+        # Failed registration
+        page.execute_script("u2f.register = function(_,_,_,callback) { callback('bad response'); };")
+        click_on 'Setup New U2F Device'
+        expect(page).to have_content('Your device was successfully set up')
+        click_on 'Register U2F Device'
+        expect(page.body).to match("The form contains the following error")
+
+        # Successful registration
+        register_u2f_device
+
+        expect(page.body).to match('Your U2F device was registered')
+        expect(U2fRegistration.count).to eq(1)
+      end
+    end
+  end
+
+  describe "authentication" do
+    let(:user) { create(:user) }
+
+    before do
+      # Register and logout
+      login_as(user)
+      visit profile_account_path
+      click_on 'Enable Two-Factor Authentication'
+      @u2f_device = register_u2f_device
+      logout
+    end
+
+    describe "when 2FA via OTP is disabled" do
+      it "allows logging in with the U2F device" do
+        login_with(user)
+
+        @u2f_device.respond_to_u2f_authentication
+        click_on "Login Via U2F Device"
+        expect(page.body).to match('We heard back from your U2F device')
+        click_on "Authenticate via U2F Device"
+
+        expect(page.body).to match('Signed in successfully')
+      end
+    end
+
+    describe "when 2FA via OTP is enabled" do
+      it "allows logging in with the U2F device" do
+        user.update_attributes(otp_required_for_login: true)
+        login_with(user)
+
+        @u2f_device.respond_to_u2f_authentication
+        click_on "Login Via U2F Device"
+        expect(page.body).to match('We heard back from your U2F device')
+        click_on "Authenticate via U2F Device"
+
+        expect(page.body).to match('Signed in successfully')
+      end
+    end
+
+    describe "when a given U2F device has already been registered by another user" do
+      describe "but not the current user" do
+        it "does not allow logging in with that particular device" do
+          # Register current user with the different U2F device
+          current_user = login_as(:user)
+          visit profile_account_path
+          click_on 'Enable Two-Factor Authentication'
+          register_u2f_device
+          logout
+
+          # Try authenticating user with the old U2F device
+          login_as(current_user)
+          @u2f_device.respond_to_u2f_authentication
+          click_on "Login Via U2F Device"
+          expect(page.body).to match('We heard back from your U2F device')
+          click_on "Authenticate via U2F Device"
+
+          expect(page.body).to match('Authentication via U2F device failed')
+        end
+      end
+
+      describe "and also the current user" do
+        it "allows logging in with that particular device" do
+          # Register current user with the same U2F device
+          current_user = login_as(:user)
+          visit profile_account_path
+          click_on 'Enable Two-Factor Authentication'
+          register_u2f_device(@u2f_device)
+          logout
+
+          # Try authenticating user with the same U2F device
+          login_as(current_user)
+          @u2f_device.respond_to_u2f_authentication
+          click_on "Login Via U2F Device"
+          expect(page.body).to match('We heard back from your U2F device')
+          click_on "Authenticate via U2F Device"
+
+          expect(page.body).to match('Signed in successfully')
+        end
+      end
+    end
+
+    describe "when a given U2F device has not been registered" do
+      it "does not allow logging in with that particular device" do
+        unregistered_device = FakeU2fDevice.new(page)
+        login_as(user)
+        unregistered_device.respond_to_u2f_authentication
+        click_on "Login Via U2F Device"
+        expect(page.body).to match('We heard back from your U2F device')
+        click_on "Authenticate via U2F Device"
+
+        expect(page.body).to match('Authentication via U2F device failed')
+      end
+    end
+  end
+
+  describe "when two-factor authentication is disabled" do
+    let(:user) { create(:user) }
+
+    before do
+      login_as(user)
+      visit profile_account_path
+      click_on 'Enable Two-Factor Authentication'
+      register_u2f_device
+    end
+
+    it "deletes u2f registrations" do
+      expect { click_on "Disable" }.to change { U2fRegistration.count }.from(1).to(0)
+    end
+  end
+end
diff --git a/spec/javascripts/fixtures/u2f/authenticate.html.haml b/spec/javascripts/fixtures/u2f/authenticate.html.haml
new file mode 100644
index 00000000000..859e79a6c9e
--- /dev/null
+++ b/spec/javascripts/fixtures/u2f/authenticate.html.haml
@@ -0,0 +1 @@
+= render partial: "u2f/authenticate", locals: { new_user_session_path: "/users/sign_in" }
diff --git a/spec/javascripts/fixtures/u2f/register.html.haml b/spec/javascripts/fixtures/u2f/register.html.haml
new file mode 100644
index 00000000000..393c0613fd3
--- /dev/null
+++ b/spec/javascripts/fixtures/u2f/register.html.haml
@@ -0,0 +1 @@
+= render partial: "u2f/register", locals: { create_u2f_profile_two_factor_auth_path: '/profile/two_factor_auth/create_u2f' }
diff --git a/spec/javascripts/u2f/authenticate_spec.coffee b/spec/javascripts/u2f/authenticate_spec.coffee
new file mode 100644
index 00000000000..e8a2892d678
--- /dev/null
+++ b/spec/javascripts/u2f/authenticate_spec.coffee
@@ -0,0 +1,52 @@
+#= require u2f/authenticate
+#= require u2f/util
+#= require u2f/error
+#= require u2f
+#= require ./mock_u2f_device
+
+describe 'U2FAuthenticate', ->
+  U2FUtil.enableTestMode()
+  fixture.load('u2f/authenticate')
+
+  beforeEach ->
+    @u2fDevice = new MockU2FDevice
+    @container = $("#js-authenticate-u2f")
+    @component = new U2FAuthenticate(@container, {}, "token")
+    @component.start()
+
+  it 'allows authenticating via a U2F device', ->
+    setupButton = @container.find("#js-login-u2f-device")
+    setupMessage = @container.find("p")
+    expect(setupMessage.text()).toContain('Insert your security key')
+    expect(setupButton.text()).toBe('Login Via U2F Device')
+    setupButton.trigger('click')
+
+    inProgressMessage = @container.find("p")
+    expect(inProgressMessage.text()).toContain("Trying to communicate with your device")
+
+    @u2fDevice.respondToAuthenticateRequest({deviceData: "this is data from the device"})
+    authenticatedMessage = @container.find("p")
+    deviceResponse = @container.find('#js-device-response')
+    expect(authenticatedMessage.text()).toContain("Click this button to authenticate with the GitLab server")
+    expect(deviceResponse.val()).toBe('{"deviceData":"this is data from the device"}')
+
+  describe "errors", ->
+    it "displays an error message", ->
+      setupButton = @container.find("#js-login-u2f-device")
+      setupButton.trigger('click')
+      @u2fDevice.respondToAuthenticateRequest({errorCode: "error!"})
+      errorMessage = @container.find("p")
+      expect(errorMessage.text()).toContain("There was a problem communicating with your device")
+
+    it "allows retrying authentication after an error", ->
+      setupButton = @container.find("#js-login-u2f-device")
+      setupButton.trigger('click')
+      @u2fDevice.respondToAuthenticateRequest({errorCode: "error!"})
+      retryButton = @container.find("#js-u2f-try-again")
+      retryButton.trigger('click')
+
+      setupButton = @container.find("#js-login-u2f-device")
+      setupButton.trigger('click')
+      @u2fDevice.respondToAuthenticateRequest({deviceData: "this is data from the device"})
+      authenticatedMessage = @container.find("p")
+      expect(authenticatedMessage.text()).toContain("Click this button to authenticate with the GitLab server")
diff --git a/spec/javascripts/u2f/mock_u2f_device.js.coffee b/spec/javascripts/u2f/mock_u2f_device.js.coffee
new file mode 100644
index 00000000000..97ed0e83a0e
--- /dev/null
+++ b/spec/javascripts/u2f/mock_u2f_device.js.coffee
@@ -0,0 +1,15 @@
+class @MockU2FDevice
+  constructor: () ->
+    window.u2f ||= {}
+
+    window.u2f.register = (appId, registerRequests, signRequests, callback) =>
+      @registerCallback = callback
+
+    window.u2f.sign = (appId, challenges, signRequests, callback) =>
+      @authenticateCallback = callback
+
+  respondToRegisterRequest: (params) =>
+    @registerCallback(params)
+
+  respondToAuthenticateRequest: (params) =>
+    @authenticateCallback(params)
diff --git a/spec/javascripts/u2f/register_spec.js.coffee b/spec/javascripts/u2f/register_spec.js.coffee
new file mode 100644
index 00000000000..0858abeca1a
--- /dev/null
+++ b/spec/javascripts/u2f/register_spec.js.coffee
@@ -0,0 +1,57 @@
+#= require u2f/register
+#= require u2f/util
+#= require u2f/error
+#= require u2f
+#= require ./mock_u2f_device
+
+describe 'U2FRegister', ->
+  U2FUtil.enableTestMode()
+  fixture.load('u2f/register')
+
+  beforeEach ->
+    @u2fDevice = new MockU2FDevice
+    @container = $("#js-register-u2f")
+    @component = new U2FRegister(@container, $("#js-register-u2f-templates"), {}, "token")
+    @component.start()
+
+  it 'allows registering a U2F device', ->
+    setupButton = @container.find("#js-setup-u2f-device")
+    expect(setupButton.text()).toBe('Setup New U2F Device')
+    setupButton.trigger('click')
+
+    inProgressMessage = @container.children("p")
+    expect(inProgressMessage.text()).toContain("Trying to communicate with your device")
+
+    @u2fDevice.respondToRegisterRequest({deviceData: "this is data from the device"})
+    registeredMessage = @container.find('p')
+    deviceResponse = @container.find('#js-device-response')
+    expect(registeredMessage.text()).toContain("Your device was successfully set up!")
+    expect(deviceResponse.val()).toBe('{"deviceData":"this is data from the device"}')
+
+  describe "errors", ->
+    it "doesn't allow the same device to be registered twice (for the same user", ->
+      setupButton = @container.find("#js-setup-u2f-device")
+      setupButton.trigger('click')
+      @u2fDevice.respondToRegisterRequest({errorCode: 4})
+      errorMessage = @container.find("p")
+      expect(errorMessage.text()).toContain("already been registered with us")
+
+    it "displays an error message for other errors", ->
+      setupButton = @container.find("#js-setup-u2f-device")
+      setupButton.trigger('click')
+      @u2fDevice.respondToRegisterRequest({errorCode: "error!"})
+      errorMessage = @container.find("p")
+      expect(errorMessage.text()).toContain("There was a problem communicating with your device")
+
+    it "allows retrying registration after an error", ->
+      setupButton = @container.find("#js-setup-u2f-device")
+      setupButton.trigger('click')
+      @u2fDevice.respondToRegisterRequest({errorCode: "error!"})
+      retryButton = @container.find("#U2FTryAgain")
+      retryButton.trigger('click')
+
+      setupButton = @container.find("#js-setup-u2f-device")
+      setupButton.trigger('click')
+      @u2fDevice.respondToRegisterRequest({deviceData: "this is data from the device"})
+      registeredMessage = @container.find("p")
+      expect(registeredMessage.text()).toContain("Your device was successfully set up!")
diff --git a/spec/models/user_spec.rb b/spec/models/user_spec.rb
index 528a79bf221..6ea8bf9bbe1 100644
--- a/spec/models/user_spec.rb
+++ b/spec/models/user_spec.rb
@@ -121,6 +121,66 @@ describe User, models: true do
     end
   end
 
+  describe "scopes" do
+    describe ".with_two_factor" do
+      it "returns users with 2fa enabled via OTP" do
+        user_with_2fa = create(:user, :two_factor_via_otp)
+        user_without_2fa = create(:user)
+        users_with_two_factor = User.with_two_factor.pluck(:id)
+
+        expect(users_with_two_factor).to include(user_with_2fa.id)
+        expect(users_with_two_factor).not_to include(user_without_2fa.id)
+      end
+
+      it "returns users with 2fa enabled via U2F" do
+        user_with_2fa = create(:user, :two_factor_via_u2f)
+        user_without_2fa = create(:user)
+        users_with_two_factor = User.with_two_factor.pluck(:id)
+
+        expect(users_with_two_factor).to include(user_with_2fa.id)
+        expect(users_with_two_factor).not_to include(user_without_2fa.id)
+      end
+
+      it "returns users with 2fa enabled via OTP and U2F" do
+        user_with_2fa = create(:user, :two_factor_via_otp, :two_factor_via_u2f)
+        user_without_2fa = create(:user)
+        users_with_two_factor = User.with_two_factor.pluck(:id)
+
+        expect(users_with_two_factor).to eq([user_with_2fa.id])
+        expect(users_with_two_factor).not_to include(user_without_2fa.id)
+      end
+    end
+
+    describe ".without_two_factor" do
+      it "excludes users with 2fa enabled via OTP" do
+        user_with_2fa = create(:user, :two_factor_via_otp)
+        user_without_2fa = create(:user)
+        users_without_two_factor = User.without_two_factor.pluck(:id)
+
+        expect(users_without_two_factor).to include(user_without_2fa.id)
+        expect(users_without_two_factor).not_to include(user_with_2fa.id)
+      end
+
+      it "excludes users with 2fa enabled via U2F" do
+        user_with_2fa = create(:user, :two_factor_via_u2f)
+        user_without_2fa = create(:user)
+        users_without_two_factor = User.without_two_factor.pluck(:id)
+
+        expect(users_without_two_factor).to include(user_without_2fa.id)
+        expect(users_without_two_factor).not_to include(user_with_2fa.id)
+      end
+
+      it "excludes users with 2fa enabled via OTP and U2F" do
+        user_with_2fa = create(:user, :two_factor_via_otp, :two_factor_via_u2f)
+        user_without_2fa = create(:user)
+        users_without_two_factor = User.without_two_factor.pluck(:id)
+
+        expect(users_without_two_factor).to include(user_without_2fa.id)
+        expect(users_without_two_factor).not_to include(user_with_2fa.id)
+      end
+    end
+  end
+
   describe "Respond to" do
     it { is_expected.to respond_to(:is_admin?) }
     it { is_expected.to respond_to(:name) }
diff --git a/spec/support/fake_u2f_device.rb b/spec/support/fake_u2f_device.rb
new file mode 100644
index 00000000000..553fe9f1fbc
--- /dev/null
+++ b/spec/support/fake_u2f_device.rb
@@ -0,0 +1,36 @@
+class FakeU2fDevice
+  def initialize(page)
+    @page = page
+  end
+  
+  def respond_to_u2f_registration
+    app_id = @page.evaluate_script('gon.u2f.app_id')
+    challenges = @page.evaluate_script('gon.u2f.challenges')
+
+    json_response = u2f_device(app_id).register_response(challenges[0])
+
+    @page.execute_script("
+    u2f.register = function(appId, registerRequests, signRequests, callback) {
+      callback(#{json_response});
+    };
+    ")
+  end
+
+  def respond_to_u2f_authentication
+    app_id = @page.evaluate_script('gon.u2f.app_id')
+    challenges = @page.evaluate_script('gon.u2f.challenges')
+    json_response = u2f_device(app_id).sign_response(challenges[0])
+
+    @page.execute_script("
+    u2f.sign = function(appId, challenges, signRequests, callback) {
+      callback(#{json_response});
+    };
+    ")
+  end
+
+  private
+
+  def u2f_device(app_id)
+    @u2f_device ||= U2F::FakeU2F.new(app_id)
+  end
+end