Add captcha if there are multiple failed login attempts

Add method to store session ids by ip

Add new specs for storing session ids

Add cleaning up records after login

Add retrieving anonymous sessions

Add login recaptcha setting

Add new setting to sessions controller

Add conditions for showing captcha

Add sessions controller specs

Add admin settings specs for login protection

Add new settings to api

Add stub to devise spec

Add new translation key

Add cr remarks

Rename class call

Add cr remarks

Change if-clause for consistency

Add cr remarks

Add code review remarks

Refactor AnonymousSession class

Add changelog entry

Move AnonymousSession class to lib

Move store unauthenticated sessions to sessions controller

Move link to recaptcha info

Regenerate text file

Improve copy on the spam page

Change action filter for storing anonymous sessions

Fix rubocop offences

Add code review remarks

4 files changed, 50 insertions, 1 deletions

diff --git a/lib/api/settings.rb b/lib/api/settings.rb
index aa9e879160d..5ac6f5bf61a 100644
--- a/lib/api/settings.rb
+++ b/lib/api/settings.rb
@@ -104,6 +104,11 @@ module API
         requires :recaptcha_site_key, type: String, desc: 'Generate site key at http://www.google.com/recaptcha'
         requires :recaptcha_private_key, type: String, desc: 'Generate private key at http://www.google.com/recaptcha'
       end
+      optional :login_recaptcha_protection_enabled, type: Boolean, desc: 'Helps prevent brute-force attacks'
+      given login_recaptcha_protection_enabled: ->(val) { val } do
+        requires :recaptcha_site_key, type: String, desc: 'Generate site key at http://www.google.com/recaptcha'
+        requires :recaptcha_private_key, type: String, desc: 'Generate private key at http://www.google.com/recaptcha'
+      end
       optional :repository_checks_enabled, type: Boolean, desc: "GitLab will periodically run 'git fsck' in all project and wiki repositories to look for silent disk corruption issues."
       optional :repository_storages, type: Array[String], desc: 'Storage paths for new projects'
       optional :require_two_factor_authentication, type: Boolean, desc: 'Require all users to set up Two-factor authentication'
diff --git a/lib/gitlab/anonymous_session.rb b/lib/gitlab/anonymous_session.rb
new file mode 100644
index 00000000000..148b6d3310d
--- /dev/null
+++ b/lib/gitlab/anonymous_session.rb
@@ -0,0 +1,39 @@
+# frozen_string_literal: true
+
+module Gitlab
+  class AnonymousSession
+    def initialize(remote_ip, session_id: nil)
+      @remote_ip = remote_ip
+      @session_id = session_id
+    end
+
+    def store_session_id_per_ip
+      Gitlab::Redis::SharedState.with do |redis|
+        redis.pipelined do
+          redis.sadd(session_lookup_name, session_id)
+          redis.expire(session_lookup_name, 24.hours)
+        end
+      end
+    end
+
+    def stored_sessions
+      Gitlab::Redis::SharedState.with do |redis|
+        redis.scard(session_lookup_name)
+      end
+    end
+
+    def cleanup_session_per_ip_entries
+      Gitlab::Redis::SharedState.with do |redis|
+        redis.srem(session_lookup_name, session_id)
+      end
+    end
+
+    private
+
+    attr_reader :remote_ip, :session_id
+
+    def session_lookup_name
+      @session_lookup_name ||= "#{Gitlab::Redis::SharedState::IP_SESSIONS_LOOKUP_NAMESPACE}:#{remote_ip}"
+    end
+  end
+end
diff --git a/lib/gitlab/recaptcha.rb b/lib/gitlab/recaptcha.rb
index 772d743c9b0..f3cbe1db901 100644
--- a/lib/gitlab/recaptcha.rb
+++ b/lib/gitlab/recaptcha.rb
@@ -3,7 +3,7 @@
 module Gitlab
   module Recaptcha
     def self.load_configurations!
-      if Gitlab::CurrentSettings.recaptcha_enabled
+      if Gitlab::CurrentSettings.recaptcha_enabled || enabled_on_login?
         ::Recaptcha.configure do |config|
           config.site_key = Gitlab::CurrentSettings.recaptcha_site_key
           config.secret_key = Gitlab::CurrentSettings.recaptcha_private_key
@@ -16,5 +16,9 @@ module Gitlab
     def self.enabled?
       Gitlab::CurrentSettings.recaptcha_enabled
     end
+
+    def self.enabled_on_login?
+      Gitlab::CurrentSettings.login_recaptcha_protection_enabled
+    end
   end
 end
diff --git a/lib/gitlab/redis/shared_state.rb b/lib/gitlab/redis/shared_state.rb
index 9066606ca21..270a19e780c 100644
--- a/lib/gitlab/redis/shared_state.rb
+++ b/lib/gitlab/redis/shared_state.rb
@@ -9,6 +9,7 @@ module Gitlab
       SESSION_NAMESPACE = 'session:gitlab'.freeze
       USER_SESSIONS_NAMESPACE = 'session:user:gitlab'.freeze
       USER_SESSIONS_LOOKUP_NAMESPACE = 'session:lookup:user:gitlab'.freeze
+      IP_SESSIONS_LOOKUP_NAMESPACE = 'session:lookup:ip:gitlab'.freeze
       DEFAULT_REDIS_SHARED_STATE_URL = 'redis://localhost:6382'.freeze
       REDIS_SHARED_STATE_CONFIG_ENV_VAR_NAME = 'GITLAB_REDIS_SHARED_STATE_CONFIG_FILE'.freeze