From 172eaeba3fd217228dead279712aecce8c3ac080 Mon Sep 17 00:00:00 2001
From: Yamagishi Kazutoshi <ykzts@desire.sh>
Date: Mon, 23 Sep 2019 22:37:45 +0900
Subject: Add config of multipart threshold for S3 (#11924)

---
 config/initializers/paperclip.rb | 1 +
 1 file changed, 1 insertion(+)

(limited to 'config/initializers')

diff --git a/config/initializers/paperclip.rb b/config/initializers/paperclip.rb
index ce4185e02..cfc95330c 100644
--- a/config/initializers/paperclip.rb
+++ b/config/initializers/paperclip.rb
@@ -25,6 +25,7 @@ if ENV['S3_ENABLED'] == 'true'
     s3_protocol: s3_protocol,
     s3_host_name: s3_hostname,
     s3_headers: {
+      'X-Amz-Multipart-Threshold' => ENV.fetch('S3_MULTIPART_THRESHOLD') { 15.megabytes },
       'Cache-Control' => 'public, max-age=315576000, immutable',
     },
     s3_permissions: ENV.fetch('S3_PERMISSION') { 'public-read' },
-- 
cgit 


From a1f04c1e3497e9dff5970038461d9f454f2650df Mon Sep 17 00:00:00 2001
From: Eugen Rochko <eugen@zeonfederated.com>
Date: Tue, 24 Sep 2019 04:35:36 +0200
Subject: Fix authentication before 2FA challenge (#11943)

Regression from #11831
---
 app/controllers/auth/sessions_controller.rb   | 61 +++++++++++++++------------
 app/models/concerns/ldap_authenticable.rb     | 44 +++++++++++++++----
 config/application.rb                         |  3 +-
 config/initializers/devise.rb                 | 11 ++---
 lib/devise/ldap_authenticatable.rb            | 55 ------------------------
 lib/devise/two_factor_ldap_authenticatable.rb | 32 ++++++++++++++
 lib/devise/two_factor_pam_authenticatable.rb  | 31 ++++++++++++++
 7 files changed, 139 insertions(+), 98 deletions(-)
 delete mode 100644 lib/devise/ldap_authenticatable.rb
 create mode 100644 lib/devise/two_factor_ldap_authenticatable.rb
 create mode 100644 lib/devise/two_factor_pam_authenticatable.rb

(limited to 'config/initializers')

diff --git a/app/controllers/auth/sessions_controller.rb b/app/controllers/auth/sessions_controller.rb
index b3113bbef..f48b17c79 100644
--- a/app/controllers/auth/sessions_controller.rb
+++ b/app/controllers/auth/sessions_controller.rb
@@ -8,6 +8,8 @@ class Auth::SessionsController < Devise::SessionsController
   skip_before_action :require_no_authentication, only: [:create]
   skip_before_action :require_functional!
 
+  prepend_before_action :authenticate_with_two_factor, if: :two_factor_enabled?, only: [:create]
+
   before_action :set_instance_presenter, only: [:new]
   before_action :set_body_classes
 
@@ -20,22 +22,9 @@ class Auth::SessionsController < Devise::SessionsController
   end
 
   def create
-    self.resource = begin
-      if user_params[:email].blank? && session[:otp_user_id].present?
-        User.find(session[:otp_user_id])
-      else
-        warden.authenticate!(auth_options)
-      end
-    end
-
-    if resource.otp_required_for_login?
-      if user_params[:otp_attempt].present? && session[:otp_user_id].present?
-        authenticate_with_two_factor_via_otp(resource)
-      else
-        prompt_for_two_factor(resource)
-      end
-    else
-      authenticate_and_respond(resource)
+    super do |resource|
+      remember_me(resource)
+      flash.delete(:notice)
     end
   end
 
@@ -49,6 +38,16 @@ class Auth::SessionsController < Devise::SessionsController
 
   protected
 
+  def find_user
+    if session[:otp_user_id]
+      User.find(session[:otp_user_id])
+    else
+      user   = User.authenticate_with_ldap(user_params) if Devise.ldap_authentication
+      user ||= User.authenticate_with_pam(user_params) if Devise.pam_authentication
+      user ||= User.find_for_authentication(email: user_params[:email])
+    end
+  end
+
   def user_params
     params.require(:user).permit(:email, :password, :otp_attempt)
   end
@@ -71,6 +70,10 @@ class Auth::SessionsController < Devise::SessionsController
     super
   end
 
+  def two_factor_enabled?
+    find_user&.otp_required_for_login?
+  end
+
   def valid_otp_attempt?(user)
     user.validate_and_consume_otp!(user_params[:otp_attempt]) ||
       user.invalidate_otp_backup_code!(user_params[:otp_attempt])
@@ -78,10 +81,24 @@ class Auth::SessionsController < Devise::SessionsController
     false
   end
 
+  def authenticate_with_two_factor
+    user = self.resource = find_user
+
+    if user_params[:otp_attempt].present? && session[:otp_user_id]
+      authenticate_with_two_factor_via_otp(user)
+    elsif user.present? && (user.encrypted_password.blank? || user.valid_password?(user_params[:password]))
+      # If encrypted_password is blank, we got the user from LDAP or PAM,
+      # so credentials are already valid
+
+      prompt_for_two_factor(user)
+    end
+  end
+
   def authenticate_with_two_factor_via_otp(user)
     if valid_otp_attempt?(user)
       session.delete(:otp_user_id)
-      authenticate_and_respond(user)
+      remember_me(user)
+      sign_in(user)
     else
       flash.now[:alert] = I18n.t('users.invalid_otp_token')
       prompt_for_two_factor(user)
@@ -90,16 +107,10 @@ class Auth::SessionsController < Devise::SessionsController
 
   def prompt_for_two_factor(user)
     session[:otp_user_id] = user.id
+    @body_classes = 'lighter'
     render :two_factor
   end
 
-  def authenticate_and_respond(user)
-    sign_in(user)
-    remember_me(user)
-
-    respond_with user, location: after_sign_in_path_for(user)
-  end
-
   private
 
   def set_instance_presenter
@@ -112,11 +123,9 @@ class Auth::SessionsController < Devise::SessionsController
 
   def home_paths(resource)
     paths = [about_path]
-
     if single_user_mode? && resource.is_a?(User)
       paths << short_account_path(username: resource.account)
     end
-
     paths
   end
 
diff --git a/app/models/concerns/ldap_authenticable.rb b/app/models/concerns/ldap_authenticable.rb
index 84ff84c4b..117993947 100644
--- a/app/models/concerns/ldap_authenticable.rb
+++ b/app/models/concerns/ldap_authenticable.rb
@@ -3,24 +3,50 @@
 module LdapAuthenticable
   extend ActiveSupport::Concern
 
-  def ldap_setup(_attributes)
-    self.confirmed_at = Time.now.utc
-    self.admin        = false
-    self.external     = true
+  class_methods do
+    def authenticate_with_ldap(params = {})
+      ldap   = Net::LDAP.new(ldap_options)
+      filter = format(Devise.ldap_search_filter, uid: Devise.ldap_uid, email: params[:email])
 
-    save!
-  end
+      if (user_info = ldap.bind_as(base: Devise.ldap_base, filter: filter, password: params[:password]))
+        ldap_get_user(user_info.first)
+      end
+    end
 
-  class_methods do
     def ldap_get_user(attributes = {})
       resource = joins(:account).find_by(accounts: { username: attributes[Devise.ldap_uid.to_sym].first })
 
       if resource.blank?
-        resource = new(email: attributes[:mail].first, agreement: true, account_attributes: { username: attributes[Devise.ldap_uid.to_sym].first })
-        resource.ldap_setup(attributes)
+        resource = new(email: attributes[:mail].first, agreement: true, account_attributes: { username: attributes[Devise.ldap_uid.to_sym].first }, admin: false, external: true, confirmed_at: Time.now.utc)
+        resource.save!
       end
 
       resource
     end
+
+    def ldap_options
+      opts = {
+        host: Devise.ldap_host,
+        port: Devise.ldap_port,
+        base: Devise.ldap_base,
+
+        auth: {
+          method: :simple,
+          username: Devise.ldap_bind_dn,
+          password: Devise.ldap_password,
+        },
+
+        connect_timeout: 10,
+      }
+
+      if [:simple_tls, :start_tls].include?(Devise.ldap_method)
+        opts[:encryption] = {
+          method: Devise.ldap_method,
+          tls_options: OpenSSL::SSL::SSLContext::DEFAULT_PARAMS.tap { |options| options[:verify_mode] = OpenSSL::SSL::VERIFY_NONE if Devise.ldap_tls_no_verify },
+        }
+      end
+
+      opts
+    end
   end
 end
diff --git a/config/application.rb b/config/application.rb
index 5fd37120d..3ced81b8f 100644
--- a/config/application.rb
+++ b/config/application.rb
@@ -13,7 +13,8 @@ require_relative '../lib/paperclip/video_transcoder'
 require_relative '../lib/paperclip/type_corrector'
 require_relative '../lib/mastodon/snowflake'
 require_relative '../lib/mastodon/version'
-require_relative '../lib/devise/ldap_authenticatable'
+require_relative '../lib/devise/two_factor_ldap_authenticatable'
+require_relative '../lib/devise/two_factor_pam_authenticatable'
 
 Dotenv::Railtie.load
 
diff --git a/config/initializers/devise.rb b/config/initializers/devise.rb
index 311583820..fd9a5a8b9 100644
--- a/config/initializers/devise.rb
+++ b/config/initializers/devise.rb
@@ -71,13 +71,10 @@ end
 
 Devise.setup do |config|
   config.warden do |manager|
-    manager.default_strategies(scope: :user).unshift :database_authenticatable
-    manager.default_strategies(scope: :user).unshift :ldap_authenticatable if Devise.ldap_authentication
-    manager.default_strategies(scope: :user).unshift :pam_authenticatable  if Devise.pam_authentication
-
-    # We handle 2FA in our own sessions controller so this gets in the way
-    manager.default_strategies(scope: :user).delete :two_factor_backupable
-    manager.default_strategies(scope: :user).delete :two_factor_authenticatable
+    manager.default_strategies(scope: :user).unshift :two_factor_ldap_authenticatable if Devise.ldap_authentication
+    manager.default_strategies(scope: :user).unshift :two_factor_pam_authenticatable  if Devise.pam_authentication
+    manager.default_strategies(scope: :user).unshift :two_factor_authenticatable
+    manager.default_strategies(scope: :user).unshift :two_factor_backupable
   end
 
   # The secret key used by Devise. Devise uses this key to generate
diff --git a/lib/devise/ldap_authenticatable.rb b/lib/devise/ldap_authenticatable.rb
deleted file mode 100644
index 6903d468d..000000000
--- a/lib/devise/ldap_authenticatable.rb
+++ /dev/null
@@ -1,55 +0,0 @@
-# frozen_string_literal: true
-
-require 'net/ldap'
-require 'devise/strategies/authenticatable'
-
-module Devise
-  module Strategies
-    class LdapAuthenticatable < Authenticatable
-      def authenticate!
-        if params[:user]
-          ldap = Net::LDAP.new(
-            host: Devise.ldap_host,
-            port: Devise.ldap_port,
-            base: Devise.ldap_base,
-            encryption: {
-              method: Devise.ldap_method,
-              tls_options: tls_options,
-            },
-            auth: {
-              method: :simple,
-              username: Devise.ldap_bind_dn,
-              password: Devise.ldap_password,
-            },
-            connect_timeout: 10
-          )
-
-          filter = format(Devise.ldap_search_filter, uid: Devise.ldap_uid, email: email)
-
-          if (user_info = ldap.bind_as(base: Devise.ldap_base, filter: filter, password: password))
-            user = User.ldap_get_user(user_info.first)
-            success!(user)
-          else
-            return fail(:invalid)
-          end
-        end
-      end
-
-      def email
-        params[:user][:email]
-      end
-
-      def password
-        params[:user][:password]
-      end
-
-      def tls_options
-        OpenSSL::SSL::SSLContext::DEFAULT_PARAMS.tap do |options|
-          options[:verify_mode] = OpenSSL::SSL::VERIFY_NONE if Devise.ldap_tls_no_verify
-        end
-      end
-    end
-  end
-end
-
-Warden::Strategies.add(:ldap_authenticatable, Devise::Strategies::LdapAuthenticatable)
diff --git a/lib/devise/two_factor_ldap_authenticatable.rb b/lib/devise/two_factor_ldap_authenticatable.rb
new file mode 100644
index 000000000..065aa2de8
--- /dev/null
+++ b/lib/devise/two_factor_ldap_authenticatable.rb
@@ -0,0 +1,32 @@
+# frozen_string_literal: true
+
+require 'net/ldap'
+require 'devise/strategies/base'
+
+module Devise
+  module Strategies
+    class TwoFactorLdapAuthenticatable < Base
+      def valid?
+        valid_params? && mapping.to.respond_to?(:authenticate_with_ldap)
+      end
+
+      def authenticate!
+        resource = mapping.to.authenticate_with_ldap(params[scope])
+
+        if resource && !resource.otp_required_for_login?
+          success!(resource)
+        else
+          fail(:invalid)
+        end
+      end
+
+      protected
+
+      def valid_params?
+        params[scope] && params[scope][:password].present?
+      end
+    end
+  end
+end
+
+Warden::Strategies.add(:two_factor_ldap_authenticatable, Devise::Strategies::TwoFactorLdapAuthenticatable)
diff --git a/lib/devise/two_factor_pam_authenticatable.rb b/lib/devise/two_factor_pam_authenticatable.rb
new file mode 100644
index 000000000..5ce723b33
--- /dev/null
+++ b/lib/devise/two_factor_pam_authenticatable.rb
@@ -0,0 +1,31 @@
+# frozen_string_literal: true
+
+require 'devise/strategies/base'
+
+module Devise
+  module Strategies
+    class TwoFactorPamAuthenticatable < Base
+      def valid?
+        valid_params? && mapping.to.respond_to?(:authenticate_with_pam)
+      end
+
+      def authenticate!
+        resource = mapping.to.authenticate_with_pam(params[scope])
+
+        if resource && !resource.otp_required_for_login?
+          success!(resource)
+        else
+          fail(:invalid)
+        end
+      end
+
+      protected
+
+      def valid_params?
+        params[scope] && params[scope][:password].present?
+      end
+    end
+  end
+end
+
+Warden::Strategies.add(:two_factor_pam_authenticatable, Devise::Strategies::TwoFactorPamAuthenticatable)
-- 
cgit 


From b02169f124b8efefa33c10a14a5b45d5f9806e3d Mon Sep 17 00:00:00 2001
From: Yamagishi Kazutoshi <ykzts@desire.sh>
Date: Wed, 25 Sep 2019 00:32:12 +0900
Subject: Cast multipart threshold to integer (#11944)

---
 config/initializers/paperclip.rb | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

(limited to 'config/initializers')

diff --git a/config/initializers/paperclip.rb b/config/initializers/paperclip.rb
index cfc95330c..f308c2841 100644
--- a/config/initializers/paperclip.rb
+++ b/config/initializers/paperclip.rb
@@ -25,7 +25,7 @@ if ENV['S3_ENABLED'] == 'true'
     s3_protocol: s3_protocol,
     s3_host_name: s3_hostname,
     s3_headers: {
-      'X-Amz-Multipart-Threshold' => ENV.fetch('S3_MULTIPART_THRESHOLD') { 15.megabytes },
+      'X-Amz-Multipart-Threshold' => ENV.fetch('S3_MULTIPART_THRESHOLD') { 15.megabytes }.to_i,
       'Cache-Control' => 'public, max-age=315576000, immutable',
     },
     s3_permissions: ENV.fetch('S3_PERMISSION') { 'public-read' },
-- 
cgit 


From a5c558f0525a6ddcdddf6b7e61b554c3446fe2d5 Mon Sep 17 00:00:00 2001
From: Yamagishi Kazutoshi <ykzts@desire.sh>
Date: Wed, 25 Sep 2019 03:28:25 +0900
Subject: Hide error message on /heath (#11947)

* Hide error message on /heath

* update health_check
---
 Gemfile                             |  4 ++--
 Gemfile.lock                        | 16 +++++++++++-----
 config/initializers/health_check.rb |  2 ++
 3 files changed, 15 insertions(+), 7 deletions(-)

(limited to 'config/initializers')

diff --git a/Gemfile b/Gemfile
index 2ab313754..7ed1a4e6b 100644
--- a/Gemfile
+++ b/Gemfile
@@ -29,7 +29,7 @@ gem 'bootsnap', '~> 1.4', require: false
 gem 'browser'
 gem 'charlock_holmes', '~> 0.7.6'
 gem 'iso-639'
-gem 'chewy', '~> 5.0'
+gem 'chewy', '~> 5.1'
 gem 'cld3', '~> 3.2.4'
 gem 'devise', '~> 4.7'
 gem 'devise-two-factor', '~> 3.1'
@@ -50,7 +50,7 @@ gem 'fastimage'
 gem 'goldfinger', '~> 2.1'
 gem 'hiredis', '~> 0.6'
 gem 'redis-namespace', '~> 1.5'
-gem 'health_check', '~> 3.0'
+gem 'health_check', git: 'https://github.com/ianheggie/health_check', ref: '0b799ead604f900ed50685e9b2d469cd2befba5b'
 gem 'htmlentities', '~> 4.3'
 gem 'http', '~> 3.3'
 gem 'http_accept_language', '~> 2.1'
diff --git a/Gemfile.lock b/Gemfile.lock
index a796d1aae..900f05ab3 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -1,3 +1,11 @@
+GIT
+  remote: https://github.com/ianheggie/health_check
+  revision: 0b799ead604f900ed50685e9b2d469cd2befba5b
+  ref: 0b799ead604f900ed50685e9b2d469cd2befba5b
+  specs:
+    health_check (4.0.0.pre)
+      rails (>= 4.0)
+
 GIT
   remote: https://github.com/rtomayko/posix-spawn
   revision: 58465d2e213991f8afb13b984854a49fcdcc980c
@@ -161,7 +169,7 @@ GEM
     case_transform (0.2)
       activesupport
     charlock_holmes (0.7.6)
-    chewy (5.0.1)
+    chewy (5.1.0)
       activesupport (>= 4.0)
       elasticsearch (>= 2.0.0)
       elasticsearch-dsl
@@ -278,8 +286,6 @@ GEM
       concurrent-ruby (~> 1.0)
     hashdiff (1.0.0)
     hashie (3.6.0)
-    health_check (3.0.0)
-      railties (>= 5.0)
     heapy (0.1.4)
     highline (2.0.1)
     hiredis (0.6.3)
@@ -687,7 +693,7 @@ DEPENDENCIES
   capistrano-yarn (~> 2.0)
   capybara (~> 3.29)
   charlock_holmes (~> 0.7.6)
-  chewy (~> 5.0)
+  chewy (~> 5.1)
   cld3 (~> 3.2.4)
   climate_control (~> 0.2)
   concurrent-ruby
@@ -708,7 +714,7 @@ DEPENDENCIES
   fuubar (~> 2.4)
   goldfinger (~> 2.1)
   hamlit-rails (~> 0.2)
-  health_check (~> 3.0)
+  health_check!
   hiredis (~> 0.6)
   htmlentities (~> 4.3)
   http (~> 3.3)
diff --git a/config/initializers/health_check.rb b/config/initializers/health_check.rb
index eece67b10..6f1e78fed 100644
--- a/config/initializers/health_check.rb
+++ b/config/initializers/health_check.rb
@@ -3,4 +3,6 @@ HealthCheck.setup do |config|
 
   config.standard_checks = %w(database migrations cache)
   config.full_checks = %w(database migrations cache)
+  
+  config.include_error_in_response_body = false
 end
-- 
cgit 


From 5f69eb89e215fe7dc02cd0dc3f39b13f1945e88b Mon Sep 17 00:00:00 2001
From: Eugen Rochko <eugen@zeonfederated.com>
Date: Sun, 29 Sep 2019 21:31:51 +0200
Subject: Add a nodeinfo endpoint (#12002)

* Add nodeinfo endpoint

* dont commit stuff from my local dev

* consistant naming since we implimented 2.1 schema

* Add some additional node info stuff

* Add nodeinfo endpoint

* dont commit stuff from my local dev

* consistant naming since we implimented 2.1 schema

* expanding this to include federation info

* codeclimate feedback

* CC feedback

* using activeserializers seems like a good idea...

* get rid of draft 2.1 version

* Reimplement 2.1, also fix metaData -> metadata

* Fix metaData -> metadata here too

* Fix nodeinfo 2.1 tests

* Implement cache for monthly user aggregate

* Useless

* Remove ostatus from the list of supported protocols

* Fix nodeinfo's open_registration reading obsolete setting variable

* Only serialize domain blocks with user-facing limitations

* Do not needlessly list noop severity in nodeinfo

* Only serialize domain blocks info in nodeinfo when they are set to be displayed to everyone

* Enable caching for nodeinfo endpoints

* Fix rendering nodeinfo

* CodeClimate fixes

* Please CodeClimate

* Change InstancePresenter#active_user_count_months for clarity

* Refactor NodeInfoSerializer#metadata

* Remove nodeinfo 2.1 support as the schema doesn't exist

* Clean-up
---
 app/controllers/well_known/nodeinfo_controller.rb  | 19 ++++++++++
 app/lib/activity_tracker.rb                        |  2 +-
 app/lib/nodeinfo/adapter.rb                        |  7 ++++
 app/presenters/instance_presenter.rb               |  4 +--
 app/serializers/nodeinfo/discovery_serializer.rb   | 11 ++++++
 app/serializers/nodeinfo/serializer.rb             | 41 ++++++++++++++++++++++
 config/initializers/inflections.rb                 |  1 +
 config/routes.rb                                   |  3 ++
 .../well_known/nodeinfo_controller_spec.rb         | 36 +++++++++++++++++++
 9 files changed, 121 insertions(+), 3 deletions(-)
 create mode 100644 app/controllers/well_known/nodeinfo_controller.rb
 create mode 100644 app/lib/nodeinfo/adapter.rb
 create mode 100644 app/serializers/nodeinfo/discovery_serializer.rb
 create mode 100644 app/serializers/nodeinfo/serializer.rb
 create mode 100644 spec/controllers/well_known/nodeinfo_controller_spec.rb

(limited to 'config/initializers')

diff --git a/app/controllers/well_known/nodeinfo_controller.rb b/app/controllers/well_known/nodeinfo_controller.rb
new file mode 100644
index 000000000..11a699ebc
--- /dev/null
+++ b/app/controllers/well_known/nodeinfo_controller.rb
@@ -0,0 +1,19 @@
+# frozen_string_literal: true
+
+module WellKnown
+  class NodeInfoController < ActionController::Base
+    include CacheConcern
+
+    before_action { response.headers['Vary'] = 'Accept' }
+
+    def index
+      expires_in 3.days, public: true
+      render_with_cache json: {}, serializer: NodeInfo::DiscoverySerializer, adapter: NodeInfo::Adapter, expires_in: 3.days, root: 'nodeinfo'
+    end
+
+    def show
+      expires_in 30.minutes, public: true
+      render_with_cache json: {}, serializer: NodeInfo::Serializer, adapter: NodeInfo::Adapter, expires_in: 30.minutes, root: 'nodeinfo'
+    end
+  end
+end
diff --git a/app/lib/activity_tracker.rb b/app/lib/activity_tracker.rb
index ae3c11b6a..81303b715 100644
--- a/app/lib/activity_tracker.rb
+++ b/app/lib/activity_tracker.rb
@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 
 class ActivityTracker
-  EXPIRE_AFTER = 90.days.seconds
+  EXPIRE_AFTER = 6.months.seconds
 
   class << self
     include Redisable
diff --git a/app/lib/nodeinfo/adapter.rb b/app/lib/nodeinfo/adapter.rb
new file mode 100644
index 000000000..1b48dcb98
--- /dev/null
+++ b/app/lib/nodeinfo/adapter.rb
@@ -0,0 +1,7 @@
+# frozen_string_literal: true
+
+class NodeInfo::Adapter < ActiveModelSerializers::Adapter::Attributes
+  def self.default_key_transform
+    :camel_lower
+  end
+end
diff --git a/app/presenters/instance_presenter.rb b/app/presenters/instance_presenter.rb
index becc92c2d..c4caeaa8c 100644
--- a/app/presenters/instance_presenter.rb
+++ b/app/presenters/instance_presenter.rb
@@ -20,8 +20,8 @@ class InstancePresenter
     Rails.cache.fetch('user_count') { User.confirmed.joins(:account).merge(Account.without_suspended).count }
   end
 
-  def active_user_count
-    Rails.cache.fetch('active_user_count') { Redis.current.pfcount(*(0..3).map { |i| "activity:logins:#{i.weeks.ago.utc.to_date.cweek}" }) }
+  def active_user_count(weeks = 4)
+    Rails.cache.fetch('active_user_count') { Redis.current.pfcount(*(0...weeks).map { |i| "activity:logins:#{i.weeks.ago.utc.to_date.cweek}" }) }
   end
 
   def status_count
diff --git a/app/serializers/nodeinfo/discovery_serializer.rb b/app/serializers/nodeinfo/discovery_serializer.rb
new file mode 100644
index 000000000..07ab2a6ee
--- /dev/null
+++ b/app/serializers/nodeinfo/discovery_serializer.rb
@@ -0,0 +1,11 @@
+# frozen_string_literal: true
+
+class NodeInfo::DiscoverySerializer < ActiveModel::Serializer
+  include RoutingHelper
+
+  attribute :links
+
+  def links
+    [{ rel: 'http://nodeinfo.diaspora.software/ns/schema/2.0', href: nodeinfo_schema_url }]
+  end
+end
diff --git a/app/serializers/nodeinfo/serializer.rb b/app/serializers/nodeinfo/serializer.rb
new file mode 100644
index 000000000..1a7d7a911
--- /dev/null
+++ b/app/serializers/nodeinfo/serializer.rb
@@ -0,0 +1,41 @@
+# frozen_string_literal: true
+
+class NodeInfo::Serializer < ActiveModel::Serializer
+  include RoutingHelper
+
+  attributes :version, :software, :protocols, :usage
+
+  def version
+    '2.0'
+  end
+
+  def software
+    { name: 'mastodon', version: Mastodon::Version.to_s }
+  end
+
+  def services
+    { outbound: [], inbound: [] }
+  end
+
+  def protocols
+    %w(activitypub)
+  end
+
+  def usage
+    {
+      users: {
+        total: instance_presenter.user_count,
+        active_month: instance_presenter.active_user_count(4),
+        active_halfyear: instance_presenter.active_user_count(24),
+      },
+
+      local_posts: instance_presenter.status_count,
+    }
+  end
+
+  private
+
+  def instance_presenter
+    @instance_presenter ||= InstancePresenter.new
+  end
+end
diff --git a/config/initializers/inflections.rb b/config/initializers/inflections.rb
index bf0cb52a3..c65153b0a 100644
--- a/config/initializers/inflections.rb
+++ b/config/initializers/inflections.rb
@@ -18,4 +18,5 @@ ActiveSupport::Inflector.inflections(:en) do |inflect|
   inflect.acronym 'PubSubHubbub'
   inflect.acronym 'ActivityStreams'
   inflect.acronym 'JsonLd'
+  inflect.acronym 'NodeInfo'
 end
diff --git a/config/routes.rb b/config/routes.rb
index f1a69cf5c..e43e201a5 100644
--- a/config/routes.rb
+++ b/config/routes.rb
@@ -24,10 +24,13 @@ Rails.application.routes.draw do
   end
 
   get '.well-known/host-meta', to: 'well_known/host_meta#show', as: :host_meta, defaults: { format: 'xml' }
+  get '.well-known/nodeinfo', to: 'well_known/nodeinfo#index', as: :nodeinfo, defaults: { format: 'json' }
   get '.well-known/webfinger', to: 'well_known/webfinger#show', as: :webfinger
   get '.well-known/change-password', to: redirect('/auth/edit')
   get '.well-known/keybase-proof-config', to: 'well_known/keybase_proof_config#show'
 
+  get '/nodeinfo/2.0', to: 'well_known/nodeinfo#show', as: :nodeinfo_schema
+
   get 'manifest', to: 'manifests#show', defaults: { format: 'json' }
   get 'intent', to: 'intents#show'
   get 'custom.css', to: 'custom_css#show', as: :custom_css
diff --git a/spec/controllers/well_known/nodeinfo_controller_spec.rb b/spec/controllers/well_known/nodeinfo_controller_spec.rb
new file mode 100644
index 000000000..12e1fa415
--- /dev/null
+++ b/spec/controllers/well_known/nodeinfo_controller_spec.rb
@@ -0,0 +1,36 @@
+require 'rails_helper'
+
+describe WellKnown::NodeInfoController, type: :controller do
+  render_views
+
+  describe 'GET #index' do
+    it 'returns json document pointing to node info' do
+      get :index
+
+      expect(response).to have_http_status(200)
+      expect(response.content_type).to eq 'application/json'
+
+      json = body_as_json
+
+      expect(json[:links]).to be_an Array
+      expect(json[:links][0][:rel]).to eq 'http://nodeinfo.diaspora.software/ns/schema/2.0'
+      expect(json[:links][0][:href]).to include 'nodeinfo/2.0'
+    end
+  end
+
+  describe 'GET #show' do
+    it 'returns json document with node info properties' do
+      get :show
+
+      expect(response).to have_http_status(200)
+      expect(response.content_type).to eq 'application/json'
+
+      json = body_as_json
+
+      expect(json[:version]).to eq '2.0'
+      expect(json[:usage]).to be_a Hash
+      expect(json[:software]).to be_a Hash
+      expect(json[:protocols]).to be_an Array
+    end
+  end
+end
-- 
cgit