Lock user after a configurable amount of failed login attempts

app/controllers/casino/sessions_controller.rb

@@ -21,12 +21,14 @@ def new
   end
 
   def create
+    return show_login_error I18n.t('login_credential_acceptor.user_is_locked') if user_locked?(params[:username])
+
     validation_result = validate_login_credentials(params[:username], params[:password])
-    if !validation_result
-      log_failed_login params[:username]
-      show_login_error I18n.t('login_credential_acceptor.invalid_login_credentials')
-    else
+    if validation_result
       sign_in(validation_result, long_term: params[:rememberMe], credentials_supplied: true)
+    else
+      handle_failed_login params[:username]
+      show_login_error I18n.t('login_credential_acceptor.invalid_login_credentials')
     end
   end
 

app/helpers/casino/sessions_helper.rb

@@ -51,9 +51,14 @@ def sign_out
     cookies.delete :tgt
   end
 
-  def log_failed_login(username)
+  def user_locked?(username)
+    CASino::User.locked.where(username: username).any?
+  end
+
+  def handle_failed_login(username)
     CASino::User.where(username: username).each do |user|
       create_login_attempt(user, false)
+      prevent_brute_force(user)
     end
   end
 
@@ -91,4 +96,10 @@ def handle_signed_in_with_service(tgt, options)
       redirect_to url, status: :see_other
     end
   end
+
+  def prevent_brute_force(user)
+    return unless user.max_failed_logins_reached?(CASino.config.max_failed_login_attempts)
+    lock_timeout_minutes = CASino.config.failed_login_lock_timeout.to_i.minutes
+    user.update locked_until: lock_timeout_minutes.from_now
+  end
 end

app/models/casino/login_attempt.rb

@@ -2,4 +2,8 @@ class CASino::LoginAttempt < ActiveRecord::Base
   include CASino::ModelConcern::BrowserInfo
 
   belongs_to :user
+
+  def failed?
+    !successful?
+  end
 end

app/models/casino/user.rb

@@ -6,7 +6,19 @@ class CASino::User < ActiveRecord::Base
   has_many :two_factor_authenticators
   has_many :login_attempts
 
+  scope :locked, -> { where('locked_until > ?', Time.now) }
+
   def active_two_factor_authenticator
     self.two_factor_authenticators.where(active: true).first
   end
+
+  def locked?
+    return false unless locked_until
+    locked_until.future?
+  end
+
+  def max_failed_logins_reached?(max)
+    return false if max.to_i <= 0
+    login_attempts.last(max).count(&:failed?) == max
+  end
 end

config/cas.yml

@@ -1,4 +1,6 @@
 defaults: &defaults
+  max_failed_login_attempts: -1 # disabled
+  failed_login_lock_timeout: 5 # minutes a user gets locked for when using max_failed_login_attempts
   service_ticket:
     lifetime_unconsumed: 299
   authenticators:

config/locales/de.yml

@@ -2,6 +2,7 @@ de:
   login_credential_acceptor:
     invalid_login_ticket: "Ihre Anfrage enthielt kein gültiges Login-Ticket."
     invalid_login_credentials: "Benutzername oder Passwort falsch."
+    user_is_locked: "Ihr Account ist wegen zu vieler falscher Loginversuche gesperrt."
   login:
     label_username: "Benutzername"
     label_password: "Passwort"

config/locales/en.yml

@@ -2,6 +2,7 @@ en:
   login_credential_acceptor:
     invalid_login_ticket: "Your login request did not include a valid login ticket."
     invalid_login_credentials: "Incorrect username or password."
+    user_is_locked: "Your user is currently locked because of failed login attempts."
   login:
     label_username: "Username"
     label_password: "Password"

config/locales/fr.yml

@@ -2,6 +2,7 @@ fr:
   login_credential_acceptor:
     invalid_login_ticket: "La demande de connexion n'inclue pas un ticket de connexion valide."
     invalid_login_credentials: "Nom d'utilisateur ou mot de passe incorrect."
+    user_is_locked: "Votre utilisateur est actuellement bloqué dû à des tentatives de connexions échouées."
   login:
     label_username: "Nom d'utilisateur"
     label_password: "Mot de passe"

db/migrate/20160810113208_add_locked_until_to_users.rb

@@ -0,0 +1,5 @@
+class AddLockedUntilToUsers < ActiveRecord::Migration
+  def change
+    add_column :casino_users, :locked_until, :datetime
+  end
+end

spec/controllers/sessions_controller_spec.rb

@@ -188,7 +188,8 @@
       let(:login_ticket) { FactoryGirl.create :login_ticket }
       let(:username) { 'testuser' }
       let(:params) { { lt: login_ticket.ticket, username: username, password: 'wrrooonnng' }}
-      let!(:user) { FactoryGirl.create :user, username: username }
+      let(:locked_until) { nil }
+      let!(:user) { FactoryGirl.create :user, authenticator: 'static', username: username, locked_until: locked_until }
 
       context 'with invalid credentials' do
         it 'renders the new template' do
@@ -208,6 +209,24 @@
           expect(CASino::LoginAttempt.last.user).to eq user
           expect(CASino::LoginAttempt.last.successful).to eq false
         end
+
+        it 'does not lock the user' do
+          expect do
+            post :create, params
+          end.to_not change { user.reload.locked? }
+        end
+
+        context 'when the maximum of failed login attempts is reached' do
+          before do
+            allow(CASino.config).to receive(:max_failed_login_attempts).and_return(1)
+          end
+
+          it 'deactivates the user' do
+            expect do
+              post :create, params
+            end.to change { user.reload.locked? }.from(false).to(true)
+          end
+        end
       end
 
       context 'with valid credentials' do
@@ -310,6 +329,8 @@
           end
 
           context 'when the user does not exist yet' do
+            before { CASino::User.destroy_all }
+
             it 'generates exactly one user' do
               lambda do
                 post :create, params
@@ -367,6 +388,20 @@
             end.should change(CASino::TicketGrantingTicket, :count).by(1)
           end
         end
+
+        context 'when the user is locked' do
+          let(:locked_until) { 5.minutes.from_now }
+
+          it 'renders the new template' do
+            post :create, params
+            expect(response).to render_template(:new)
+          end
+
+          it 'sets a flash to inform the user' do
+            post :create, params
+            expect(flash[:error]).to be_present
+          end
+        end
       end
     end
   end

spec/dummy/config/cas.yml

@@ -1,4 +1,6 @@
 defaults: &defaults
+  max_failed_login_attempts: 5
+  failed_login_lock_timeout: 5
   login_ticket:
     lifetime: 600
   service_ticket:

spec/dummy/db/migrate/20160810122605_add_locked_until_to_users.casino.rb

@@ -0,0 +1,6 @@
+# This migration comes from casino (originally 20160810113208)
+class AddLockedUntilToUsers < ActiveRecord::Migration
+  def change
+    add_column :casino_users, :locked_until, :datetime
+  end
+end

spec/dummy/db/schema.rb

@@ -11,7 +11,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 20160502074450) do
+ActiveRecord::Schema.define(version: 20160810122605) do
 
   create_table "casino_auth_token_tickets", force: true do |t|
     t.string   "ticket",     null: false
@@ -119,6 +119,7 @@
     t.text     "extra_attributes"
     t.datetime "created_at"
     t.datetime "updated_at"
+    t.datetime "locked_until"
   end
 
   add_index "casino_users", ["authenticator", "username"], name: "index_casino_users_on_authenticator_and_username", unique: true

spec/model/login_attempt_spec.rb

@@ -4,4 +4,16 @@
   subject { described_class.new user_agent: 'TestBrowser' }
 
   it_behaves_like 'has browser info'
+
+  describe '#failed?' do
+    it 'is true when it is not successful' do
+      login_attempt = FactoryGirl.create :login_attempt, successful: false
+      expect(login_attempt).to be_failed
+    end
+
+    it 'is false when it is successful' do
+      login_attempt = FactoryGirl.create :login_attempt, successful: true
+      expect(login_attempt).to_not be_failed
+    end
+  end
 end

spec/model/user_spec.rb

@@ -0,0 +1,73 @@
+require 'spec_helper'
+
+RSpec.describe CASino::User do
+  let(:user) { FactoryGirl.create :user }
+
+  describe '#locked?' do
+    it 'is true when locked_until is in the future' do
+      user = FactoryGirl.create :user, locked_until: 1.hour.from_now
+      expect(user).to be_locked
+    end
+
+    it 'is false when locked_until is in the past' do
+      user = FactoryGirl.create :user, locked_until: 1.hour.ago
+      expect(user).to_not be_locked
+    end
+
+    it 'is false when locked_until is empty' do
+      user = FactoryGirl.create :user, locked_until: nil
+      expect(user).to_not be_locked
+    end
+  end
+
+  describe '#max_failed_logins_reached?' do
+    let(:max_failed_attempts) { 2 }
+
+    subject { user.max_failed_logins_reached?(max_failed_attempts) }
+
+    context 'when the user has no login attempts' do
+      it { is_expected.to eq false }
+    end
+
+    context 'when the user has only successful logins' do
+      it { is_expected.to eq false }
+    end
+
+    context 'when the feature is disabled' do
+      let(:max_failed_attempts) { -1 }
+      it { is_expected.to eq false }
+    end
+
+    context 'when the maxium value is invalid' do
+      let(:max_failed_attempts) { nil }
+      it { is_expected.to eq false }
+    end
+
+    context 'when the maximum of attempts is reached' do
+      before { FactoryGirl.create_list :login_attempt, 2, successful: false, user: user }
+
+      context 'in a row' do
+        it { is_expected.to eq true }
+      end
+
+      context 'but the last attempt was successful' do
+        before { FactoryGirl.create :login_attempt, successful: true, user: user }
+        it { is_expected.to eq false }
+      end
+
+      context 'but a successful between' do
+        before do
+          FactoryGirl.create :login_attempt, successful: true, user: user
+          FactoryGirl.create :login_attempt, successful: false, user: user
+        end
+
+        it { is_expected.to eq false }
+      end
+    end
+
+    context 'when the user has less then the maximum failed attempts' do
+      before { FactoryGirl.create :login_attempt, successful: false, user: user }
+      it { is_expected.to eq false }
+    end
+  end
+end