Add WebAuthn as an alternative 2FA method (#14466)

* feat: add possibility of adding WebAuthn security keys to use as 2FA

This adds a basic UI for enabling WebAuthn 2FA. We did a little refactor
to the Settings page for editing the 2FA methods – now it will list the
methods that are available to the user (TOTP and WebAuthn) and from
there they'll be able to add or remove any of them.
Also, it's worth mentioning that for enabling WebAuthn it's required to
have TOTP enabled, so the first time that you go to the 2FA Settings
page, you'll be asked to set it up.
This work was inspired by the one donde by Github in their platform, and
despite it could be approached in different ways, we decided to go with
this one given that we feel that this gives a great UX.

Co-authored-by: Facundo Padula <facundo.padula@cedarcode.com>

* feat: add request for WebAuthn as second factor at login if enabled

This commits adds the feature for using WebAuthn as a second factor for
login when enabled.
If users have WebAuthn enabled, now a page requesting for the use of a
WebAuthn credential for log in will appear, although a link redirecting
to the old page for logging in using a two-factor code will also be
present.

Co-authored-by: Facundo Padula <facundo.padula@cedarcode.com>

* feat: add possibility of deleting WebAuthn Credentials

Co-authored-by: Facundo Padula <facundo.padula@cedarcode.com>

* feat: disable WebAuthn when an Admin disables 2FA for a user

Co-authored-by: Facundo Padula <facundo.padula@cedarcode.com>

* feat: remove ability to disable TOTP leaving only WebAuthn as 2FA

Following examples form other platforms like Github, we decided to make
Webauthn 2FA secondary to 2FA with TOTP, so that we removed the
possibility of removing TOTP authentication only, leaving users with
just WEbAuthn as 2FA. Instead, users will have to click on 'Disable 2FA'
in order to remove second factor auth.
The reason for WebAuthn being secondary to TOPT is that in that way,
users will still be able to log in using their code from their phone's
application if they don't have their security keys with them – or maybe
even lost them.

* We had to change a little the flow for setting up TOTP, given that now
  it's possible to setting up again if you already had TOTP, in order to
  let users modify their authenticator app – given that now it's not
  possible for them to disable TOTP and set it up again with another
  authenticator app.
  So, basically, now instead of storing the new `otp_secret` in the
  user, we store it in the session until the process of set up is
  finished.
  This was because, as it was before, when users clicked on 'Edit' in
  the new two-factor methods lists page, but then went back without
  finishing the flow, their `otp_secret` had been changed therefore
  invalidating their previous authenticator app, making them unable to
  log in again using TOTP.

Co-authored-by: Facundo Padula <facundo.padula@cedarcode.com>

* refactor: fix eslint errors

The PR build was failing given that linting returning some errors.
This commit attempts to fix them.

* refactor: normalize i18n translations

The build was failing given that i18n translations files were not
normalized.
This commits fixes that.

* refactor: avoid having the webauthn gem locked to a specific version

* refactor: use symbols for routes without '/'

* refactor: avoid sending webauthn disabled email when 2FA is disabled

When an admins disable 2FA for users, we were sending two mails
to them, one notifying that 2FA was disabled and the other to notify
that WebAuthn was disabled.
As the second one is redundant since the first email includes it, we can
remove it and send just one email to users.

* refactor: avoid creating new env variable for webauthn_origin config

* refactor: improve flash error messages for webauthn pages

Co-authored-by: Facundo Padula <facundo.padula@cedarcode.com>

1 files changed, 136 insertions, 55 deletions

diff --git a/spec/controllers/auth/sessions_controller_spec.rb b/spec/controllers/auth/sessions_controller_spec.rb
index c387842cd..8ad9e74fc 100644
--- a/spec/controllers/auth/sessions_controller_spec.rb
+++ b/spec/controllers/auth/sessions_controller_spec.rb
@@ -1,6 +1,7 @@
 # frozen_string_literal: true
 
 require 'rails_helper'
+require 'webauthn/fake_client'
 
 RSpec.describe Auth::SessionsController, type: :controller do
   render_views
@@ -183,90 +184,170 @@ RSpec.describe Auth::SessionsController, type: :controller do
     end
 
     context 'using two-factor authentication' do
-      let!(:user) do
-        Fabricate(:user, email: 'x@y.com', password: 'abcdefgh', otp_required_for_login: true, otp_secret: User.generate_otp_secret(32))
-      end
-
-      let!(:recovery_codes) do
-        codes = user.generate_otp_backup_codes!
-        user.save
-        return codes
-      end
-
-      context 'using email and password' do
-        before do
-          post :create, params: { user: { email: user.email, password: user.password } }
+      context 'with OTP enabled as second factor' do
+        let!(:user) do
+          Fabricate(:user, email: 'x@y.com', password: 'abcdefgh', otp_required_for_login: true, otp_secret: User.generate_otp_secret(32))
         end
 
-        it 'renders two factor authentication page' do
-          expect(controller).to render_template("two_factor")
+        let!(:recovery_codes) do
+          codes = user.generate_otp_backup_codes!
+          user.save
+          return codes
         end
-      end
 
-      context 'using upcase email and password' do
-        before do
-          post :create, params: { user: { email: user.email.upcase, password: user.password } }
-        end
+        context 'using email and password' do
+          before do
+            post :create, params: { user: { email: user.email, password: user.password } }
+          end
 
-        it 'renders two factor authentication page' do
-          expect(controller).to render_template("two_factor")
+          it 'renders two factor authentication page' do
+            expect(controller).to render_template("two_factor")
+            expect(controller).to render_template(partial: "_otp_authentication_form")
+          end
         end
-      end
 
-      context 'using a valid OTP' do
-        before do
-          post :create, params: { user: { otp_attempt: user.current_otp } }, session: { attempt_user_id: user.id }
-        end
+        context 'using upcase email and password' do
+          before do
+            post :create, params: { user: { email: user.email.upcase, password: user.password } }
+          end
 
-        it 'redirects to home' do
-          expect(response).to redirect_to(root_path)
+          it 'renders two factor authentication page' do
+            expect(controller).to render_template("two_factor")
+            expect(controller).to render_template(partial: "_otp_authentication_form")
+          end
         end
 
-        it 'logs the user in' do
-          expect(controller.current_user).to eq user
+        context 'using a valid OTP' do
+          before do
+            post :create, params: { user: { otp_attempt: user.current_otp } }, session: { attempt_user_id: user.id }
+          end
+
+          it 'redirects to home' do
+            expect(response).to redirect_to(root_path)
+          end
+
+          it 'logs the user in' do
+            expect(controller.current_user).to eq user
+          end
         end
-      end
 
-      context 'when the server has an decryption error' do
-        before do
-          allow_any_instance_of(User).to receive(:validate_and_consume_otp!).and_raise(OpenSSL::Cipher::CipherError)
-          post :create, params: { user: { otp_attempt: user.current_otp } }, session: { attempt_user_id: user.id }
+        context 'when the server has an decryption error' do
+          before do
+            allow_any_instance_of(User).to receive(:validate_and_consume_otp!).and_raise(OpenSSL::Cipher::CipherError)
+            post :create, params: { user: { otp_attempt: user.current_otp } }, session: { attempt_user_id: user.id }
+          end
+
+          it 'shows a login error' do
+            expect(flash[:alert]).to match I18n.t('users.invalid_otp_token')
+          end
+
+          it "doesn't log the user in" do
+            expect(controller.current_user).to be_nil
+          end
         end
 
-        it 'shows a login error' do
-          expect(flash[:alert]).to match I18n.t('users.invalid_otp_token')
+        context 'using a valid recovery code' do
+          before do
+            post :create, params: { user: { otp_attempt: recovery_codes.first } }, session: { attempt_user_id: user.id }
+          end
+
+          it 'redirects to home' do
+            expect(response).to redirect_to(root_path)
+          end
+
+          it 'logs the user in' do
+            expect(controller.current_user).to eq user
+          end
         end
 
-        it "doesn't log the user in" do
-          expect(controller.current_user).to be_nil
+        context 'using an invalid OTP' do
+          before do
+            post :create, params: { user: { otp_attempt: 'wrongotp' } }, session: { attempt_user_id: user.id }
+          end
+
+          it 'shows a login error' do
+            expect(flash[:alert]).to match I18n.t('users.invalid_otp_token')
+          end
+
+          it "doesn't log the user in" do
+            expect(controller.current_user).to be_nil
+          end
         end
       end
 
-      context 'using a valid recovery code' do
-        before do
-          post :create, params: { user: { otp_attempt: recovery_codes.first } }, session: { attempt_user_id: user.id }
+      context 'with WebAuthn and OTP enabled as second factor' do
+        let!(:user) do
+          Fabricate(:user, email: 'x@y.com', password: 'abcdefgh', otp_required_for_login: true, otp_secret: User.generate_otp_secret(32))
         end
 
-        it 'redirects to home' do
-          expect(response).to redirect_to(root_path)
+        let!(:recovery_codes) do
+          codes = user.generate_otp_backup_codes!
+          user.save
+          return codes
         end
 
-        it 'logs the user in' do
-          expect(controller.current_user).to eq user
+        let!(:webauthn_credential) do
+          user.update(webauthn_id: WebAuthn.generate_user_id)
+          public_key_credential = WebAuthn::Credential.from_create(fake_client.create)
+          user.webauthn_credentials.create(
+            nickname: 'SecurityKeyNickname',
+            external_id: public_key_credential.id,
+            public_key: public_key_credential.public_key,
+            sign_count: '1000'
+           )
+          user.webauthn_credentials.take
         end
-      end
 
-      context 'using an invalid OTP' do
-        before do
-          post :create, params: { user: { otp_attempt: 'wrongotp' } }, session: { attempt_user_id: user.id }
+        let(:domain) { "#{Rails.configuration.x.use_https ? 'https' : 'http' }://#{Rails.configuration.x.web_domain}" }
+
+        let(:fake_client) { WebAuthn::FakeClient.new(domain) }
+
+        let(:challenge) { WebAuthn::Credential.options_for_get.challenge }
+
+        let(:sign_count) { 1234 }
+
+        let(:fake_credential) { fake_client.get(challenge: challenge, sign_count: sign_count) }
+
+        context 'using email and password' do
+          before do
+            post :create, params: { user: { email: user.email, password: user.password } }
+          end
+
+          it 'renders webauthn authentication page' do
+            expect(controller).to render_template("two_factor")
+            expect(controller).to render_template(partial: "_webauthn_form")
+          end
         end
 
-        it 'shows a login error' do
-          expect(flash[:alert]).to match I18n.t('users.invalid_otp_token')
+        context 'using upcase email and password' do
+          before do
+            post :create, params: { user: { email: user.email.upcase, password: user.password } }
+          end
+
+          it 'renders webauthn authentication page' do
+            expect(controller).to render_template("two_factor")
+            expect(controller).to render_template(partial: "_webauthn_form")
+          end
         end
 
-        it "doesn't log the user in" do
-          expect(controller.current_user).to be_nil
+        context 'using a valid webauthn credential' do
+          before do
+            @controller.session[:webauthn_challenge] = challenge
+
+            post :create, params: { user: { credential: fake_credential } }, session: { attempt_user_id: user.id }
+          end
+
+          it 'instructs the browser to redirect to home' do
+            expect(body_as_json[:redirect_path]).to eq(root_path)
+          end
+
+          it 'logs the user in' do
+            expect(controller.current_user).to eq user
+          end
+
+          it 'updates the sign count' do
+            expect(webauthn_credential.reload.sign_count).to eq(sign_count)
+          end
         end
       end
     end