diff --git a/.gitignore b/.gitignore
index e3200e0..03a0905 100644
--- a/.gitignore
+++ b/.gitignore
@@ -54,3 +54,10 @@ build-iPhoneSimulator/
 
 # Used by RuboCop. Remote config files pulled in from inherit_from directive.
 # .rubocop-https?--*
+
+temp/
+output/
+license_key
+license_key.pub
+result.gitlab-license
+features.list
diff --git a/.root b/.root
new file mode 100644
index 000000000..e69de29
diff --git a/feature.scan.py b/feature.scan.py
new file mode 100755
index 000000000..b0fcc87
--- /dev/null
+++ b/feature.scan.py
@@ -0,0 +1,49 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+
+import re
+import os
+import sys
+
+SCANNING_DIR = sys.argv[1]
+OUTPUT_LIST_FILE = sys.argv[2]
+print(f"[*] scanning directory: {SCANNING_DIR}")
+
+# use regex to find the string
+# eg ::License.feature_available?(:aaa) || ::Feature.enabled?(:bbb, self)
+# make sure +? for shortest match
+REGEX_PARTTERN = "License.feature_available\?\(:.+?\)"
+
+REQUIRED_FILE_SUFFIX = ['rb']
+
+scanning_file_list = set()
+def build_file_list(input: str):
+    global scanning_file_list
+    scanning_file_list.add(input)
+    if os.path.isdir(input):
+        for file in os.listdir(input): 
+            build_file_list(os.path.join(input, file))
+build_file_list(SCANNING_DIR)
+
+print(f"[*] scanning {len(scanning_file_list)} files...")
+feature_list=set()
+for file in scanning_file_list:
+    if not os.path.isfile(file): continue
+    if not file.split(".")[-1] in REQUIRED_FILE_SUFFIX: continue
+    with open(file, "r") as f:
+        content = f.read()
+        all_match = re.findall(REGEX_PARTTERN, content)
+        all_match = [x.split(":")[1].split(")")[0] for x in all_match]
+        all_match = [x for x in all_match if x]
+        feature_list.update(all_match)
+print(f"[*] found {len(feature_list)} features")
+
+feature_list = list(feature_list)
+feature_list.sort()
+
+print(f"[*] writing to {OUTPUT_LIST_FILE}...")
+with open(OUTPUT_LIST_FILE, "w") as f:
+    for feature in feature_list:
+        f.write(feature + "\n")
+
+print(f"[*] done")
diff --git a/generate_licenses.rb b/generate_licenses.rb
index 87e25a9..344b4bc 100644
--- a/generate_licenses.rb
+++ b/generate_licenses.rb
@@ -1,31 +1,47 @@
-# GitLab License Generator
+#!/usr/bin/env ruby
+# encoding: utf-8
+
+require 'openssl'
+require_relative 'lib/license.rb'
+puts "[i] lib gitlab-license: #{Gitlab::License::VERSION}"
+
+OUTPUT_DIR = ARGV[0]
+puts "[*] output dir: #{OUTPUT_DIR}"
 
 LICENSE_TARGET_PRIVATE_KEY = "license_key"
 LICENSE_TARGET_PUBLIC_KEY = "license_key.pub"
 TARGET_LICENSE_FILE = 'result.gitlab-license'
+TARGET_PLAIN_LICENSE_FILE = 'result.gitlab-license.json'
 
-puts "[*] Booting generator"
+FEATURE_LIST = []
+if ARGV[1].nil?
+  puts "[i] you can provide a list of feature to be enabled inside license"
+else
+  FEATURE_LIST_FILE = ARGV[1]
+  File.open(FEATURE_LIST_FILE).each do |line|
+    FEATURE_LIST.push(line.chomp)
+  end
+  FEATURE_LIST.uniq!
+end
+puts "[*] loaded #{FEATURE_LIST.length} features"
 
-require 'openssl'
-
-require_relative 'lib/license.rb'
-CORE_LIB_VERSION = '2.2.1'
-
-puts "[i] Using core library version #{CORE_LIB_VERSION}"
+Dir.chdir(OUTPUT_DIR)
+puts "[*] switching working dir: #{Dir.pwd}"
 
+puts "[*] generating license..."
 if !File.exist?(LICENSE_TARGET_PRIVATE_KEY) || !File.exist?(LICENSE_TARGET_PUBLIC_KEY)
-  puts "[*] Generating RSA keys..."
+  puts "[*] generating rsa key pair..."
   key = OpenSSL::PKey::RSA.new(2048)
   File.write(LICENSE_TARGET_PRIVATE_KEY, key.to_pem)
   File.write(LICENSE_TARGET_PUBLIC_KEY, key.public_key.to_pem)
 end
 
-puts "[*] Loading RSA keys..."
+puts "[*] loading key pair..."
 
 public_key = OpenSSL::PKey::RSA.new File.read(LICENSE_TARGET_PUBLIC_KEY)
 private_key = OpenSSL::PKey::RSA.new File.read(LICENSE_TARGET_PRIVATE_KEY)
 
-puts "[*] Building license..."
+puts "[*] building license..."
 
 Gitlab::License.encryption_key = private_key
 
@@ -59,20 +75,17 @@ license.restrictions      = {
   # required, just dont overflow
 }
 
-puts "[*] Calling export..."
+if !license.valid?
+  puts "[E] license validation failed!"
+  puts "[E] #{license.errors}"
+  exit 1
+end
 
-puts ""
-puts "====================================================="
+puts "[*] exporting license file..."
 
-puts JSON.pretty_generate(JSON.parse(license.to_json))
-
-puts "====================================================="
+File.open(TARGET_PLAIN_LICENSE_FILE, "w") { |f| f.write(JSON.pretty_generate(JSON.parse(license.to_json))) }
 
 data = license.export
 File.open(TARGET_LICENSE_FILE, "w") { |f| f.write(data) }
 
-puts "====================================================="
-puts ""
-
-puts "[*] License generated successfully!"
-puts "[*] License file: #{TARGET_LICENSE_FILE}"
+puts "[*] done"
diff --git a/lib/license.rb b/lib/license.rb
index eaac533..c2648b5 100644
--- a/lib/license.rb
+++ b/lib/license.rb
@@ -15,6 +15,7 @@ module Gitlab
 
     class << self
       attr_reader :encryption_key
+      attr_reader :fallback_decryption_keys
       @encryption_key = nil
 
       def encryption_key=(key)
@@ -24,6 +25,19 @@ module Gitlab
         @encryptor = nil
       end
 
+      def fallback_decryption_keys=(keys)
+        unless keys
+          @fallback_decryption_keys = nil
+          return
+        end
+
+        unless keys.is_a?(Enumerable) && keys.all? { |key| key.is_a?(OpenSSL::PKey::RSA) }
+          raise ArgumentError, 'Invalid fallback RSA encryption keys provided.'
+        end
+
+        @fallback_decryption_keys = Array(keys)
+      end
+
       def encryptor
         @encryptor ||= Encryptor.new(encryption_key)
       end
@@ -33,11 +47,7 @@ module Gitlab
 
         data = Boundary.remove_boundary(data)
 
-        begin
-          license_json = encryptor.decrypt(data)
-        rescue Encryptor::Error
-          raise ImportError, 'License data could not be decrypted.'
-        end
+        license_json = decrypt_with_fallback_keys(data)
 
         begin
           attributes = JSON.parse(license_json)
@@ -47,6 +57,20 @@ module Gitlab
 
         new(attributes)
       end
+
+      def decrypt_with_fallback_keys(data)
+        keys_to_try = Array(encryption_key)
+        keys_to_try += fallback_decryption_keys if fallback_decryption_keys
+
+        keys_to_try.each do |decryption_key|
+          decryptor = Encryptor.new(decryption_key)
+          return decryptor.decrypt(data)
+        rescue Encryptor::Error
+          next
+        end
+
+        raise ImportError, 'License data could not be decrypted.'
+      end
     end
 
     attr_reader :version
@@ -54,7 +78,8 @@ module Gitlab
                   :notify_users_at, :block_changes_at, :last_synced_at, :next_sync_at,
                   :activated_at, :restrictions, :cloud_licensing_enabled,
                   :offline_cloud_licensing_enabled, :auto_renew_enabled, :seat_reconciliation_enabled,
-                  :operational_metrics_enabled, :generated_from_customers_dot
+                  :operational_metrics_enabled, :generated_from_customers_dot,
+                  :generated_from_cancellation
 
     alias_method :issued_at, :starts_at
     alias_method :issued_at=, :starts_at=
@@ -65,43 +90,30 @@ module Gitlab
 
     def valid?
       if !licensee || !licensee.is_a?(Hash) || licensee.empty?
-        puts "Invalid License - licensee is not a hash or is empty"
         false
       elsif !starts_at || !starts_at.is_a?(Date)
-        puts "Invalid License - starts_at is not a date"
         false
       elsif !expires_at && !gl_team_license? && !jh_team_license?
-        puts "Invalid License - expires_at is not a date"
         false
       elsif expires_at && !expires_at.is_a?(Date)
-        puts "Invalid License - expires_at is not a date"
         false
       elsif notify_admins_at && !notify_admins_at.is_a?(Date)
-        puts "Invalid License - notify_admins_at is not a date"
         false
       elsif notify_users_at && !notify_users_at.is_a?(Date)
-        puts "Invalid License - notify_users_at is not a date"
         false
       elsif block_changes_at && !block_changes_at.is_a?(Date)
-        puts "Invalid License - block_changes_at is not a date"
         false
       elsif last_synced_at && !last_synced_at.is_a?(DateTime)
-        puts "Invalid License - last_synced_at is not a datetime"
         false
       elsif next_sync_at && !next_sync_at.is_a?(DateTime)
-        puts "Invalid License - next_sync_at is not a datetime"
         false
       elsif activated_at && !activated_at.is_a?(DateTime)
-        puts "Invalid License - activated_at is not a datetime"
         false
       elsif restrictions && !restrictions.is_a?(Hash)
-        puts "Invalid License - restrictions is not a hash"
         false
       elsif !cloud_licensing? && offline_cloud_licensing?
-        puts "Invalid License - offline_cloud_licensing_enabled is true but cloud_licensing_enabled is false"
         false
       else
-        puts "License is valid"
         true
       end
     end
@@ -174,6 +186,10 @@ module Gitlab
       generated_from_customers_dot == true
     end
 
+    def generated_from_cancellation?
+      generated_from_cancellation == true
+    end
+
     def gl_team_license?
       licensee['Company'].to_s.match?(/GitLab/i) && licensee['Email'].to_s.end_with?('@gitlab.com')
     end
@@ -216,6 +232,7 @@ module Gitlab
       hash['operational_metrics_enabled'] = operational_metrics?
 
       hash['generated_from_customers_dot'] = generated_from_customers_dot?
+      hash['generated_from_cancellation'] = generated_from_cancellation?
 
       hash['restrictions'] = restrictions if restricted?
 
@@ -265,6 +282,7 @@ module Gitlab
         seat_reconciliation_enabled
         operational_metrics_enabled
         generated_from_customers_dot
+        generated_from_cancellation
       ].each do |attr_name|
         public_send("#{attr_name}=", attributes[attr_name] == true)
       end
diff --git a/lib/license/version.rb b/lib/license/version.rb
index 3b734b9..c0c6742 100644
--- a/lib/license/version.rb
+++ b/lib/license/version.rb
@@ -1,5 +1,5 @@
 module Gitlab
   class License
-    VERSION = '2.2.1'.freeze
+    VERSION = '2.4.0'.freeze
   end
 end
diff --git a/license_key b/license_key
deleted file mode 100644
index 8ed3b3a..000000000
--- a/license_key
+++ /dev/null
@@ -1,27 +0,0 @@
------BEGIN RSA PRIVATE KEY-----
-MIIEowIBAAKCAQEAreEfP/ncA1A5cuxBz7rS0Z9DDxdSymLwt2OUSM5WJa+dVB3z
-SpQjinifdNZq+iHVt8toZBZZ02H3unbn8td0rIifoj4oVpLhvnOAVjUn5tZeUX17
-tWMA+yyBpf6w6IFxeYBXFd14WOKEarS05U9B59DjBxNqSm+GzhljHO7vvTKy2xXQ
-Q7Fa702DZ7jwr4DJnL87bDXfarnYksuawqtKwQbFHAOvxFj8ghBh1Gshap1abExD
-4l7QWxFMTCVOkLJmXiqfOi5KuMiaMsSUsCBNQDE3A5aKvpwLGozsvpGRMy5Tt4Sg
-HC7ZbgerBNe75olOoPDxZf7bBt0+O5A/UjK/HwIDAQABAoIBACb3f4hX112KugUu
-OyVxidNebKnSIUSn3ahLkayrSRUTASAbwi0he8GJfLqzXrAFqx6QYCml9KVxnBHW
-me6LKGOODrBOW73jFuIWgllPeky6F9MNWw7wTAT+GWP46u6AK8z93QZSZqkMwn4j
-VzLYiz2HS4mHaVebHMvNVq/iQCnW9ztZnsv9HSoFt2WY2Cm/9UpAtbqrWRQTVnCt
-F7E1M9KICUKyM13qOQe+d0sZWx6D8eKrFlPs4KDXATs2SuDsaWpmWj9G8alSeHEW
-Ut+2MsS5BYNIVaG0KqDFRKDyTkhXzevz98r5KylFqfAB2bCnaqIE0hdOXfYd+CR0
-wwRAQmECgYEA1CnEO0K+nU8tZUwdTkL3wvo6z2jEnA97Laay9D/fnAjd3q8niTyJ
-2DZQJp9omTa51/7EJw6YWhYdk078ZckwebWQPtXsA7MCTXSXL3+sGmL2GohDUovH
-G6zdn9sKws+U6tIOoEOMCLivEtmNM7HJXP3PViQr+rOUQV3ig/8v+s8CgYEA0c5c
-Or0Ta4apaM8aD6rP2Eilb3VC8AOvSzY36gN38ki/SwVH1ZTw/hbOYlQTsnk+OkXX
-205k9tc78+9GrcYSuupjqzEdZVRQSGSbT9qXMMYfM3wK2Z7i37Cehn4Qw4BOOlgR
-TvsvBd0FSnzVi2wAkhx0zL1hNUXHHAYnVdOxyrECgYEAwKbkb0NePw4ElLUW71fU
-DxKVkHz7+xH7sipq2WueqttKTMkTx4RXTyOSiF+75VRSURYgG68fHL50QK06d1rH
-T91UjBpIY9uKvbafChyOtK8j9lfBehU+yZyg6mVGUjuYZ9oyOcjcQZciMqWlmEla
-Jby7JudVoCKs/uY3p9BzSvUCgYAF7Pkn44033T7NqgPHa4ChUDPz+PDiDIiX7Dka
-D+0EV8+nU8fanXFNC+HaXxuLT+dVCAH3vLgXTK7xzdFGOTDwPIyCGkoFQaNe2BCW
-6cqZYw8giiFYUieAP+HKVKcujmInPbOHcoq6dKqglvQFExDVD56w5axoL8dW4Eme
-H/OGkQKBgHgQeK29Ntz7LcKlXYhQPkmYn+DWAmEq4J6XjjXyCV82HgEMmhIiAKKI
-UURKt4j6c7KSiAhnyITz9JeVRoAFVB3y/tSSc5E+CH3jG/G0YlToW20Itf6o8hwD
-XERkPPwsXVoZWR2FcUzcO7Bspm/JvkuaL+4u1fi+eNl7uF7RRaD1
------END RSA PRIVATE KEY-----
diff --git a/license_key.pub b/license_key.pub
deleted file mode 100644
index 64eb81d..000000000
--- a/license_key.pub
+++ /dev/null
@@ -1,9 +0,0 @@
------BEGIN PUBLIC KEY-----
-MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAreEfP/ncA1A5cuxBz7rS
-0Z9DDxdSymLwt2OUSM5WJa+dVB3zSpQjinifdNZq+iHVt8toZBZZ02H3unbn8td0
-rIifoj4oVpLhvnOAVjUn5tZeUX17tWMA+yyBpf6w6IFxeYBXFd14WOKEarS05U9B
-59DjBxNqSm+GzhljHO7vvTKy2xXQQ7Fa702DZ7jwr4DJnL87bDXfarnYksuawqtK
-wQbFHAOvxFj8ghBh1Gshap1abExD4l7QWxFMTCVOkLJmXiqfOi5KuMiaMsSUsCBN
-QDE3A5aKvpwLGozsvpGRMy5Tt4SgHC7ZbgerBNe75olOoPDxZf7bBt0+O5A/UjK/
-HwIDAQAB
------END PUBLIC KEY-----
diff --git a/make.sh b/make.sh
index dc2541d..2f7649e 100755
--- a/make.sh
+++ b/make.sh
@@ -1,4 +1,81 @@
-#!/bin/bash
+#!/bin/zsh
 
-cd "$(dirname "$0")" || exit 1
-ruby ./generate_licenses.rb
\ No newline at end of file
+set -e
+
+cd "$(dirname "$0")"
+if [ ! -f ".root" ]; then
+    echo "[!] failed to locate project directory, aborting..."
+    exit 1
+fi
+WORKING_DIR=$(pwd)
+
+mkdir temp || true
+
+echo "[*] fetching ruby gem version..."
+RB_GEM_NAME="gitlab-license"
+RB_GEM_LIST_OUTPUT=$(gem list --remote $RB_GEM_NAME)
+
+RB_GEM_VERSION=""
+while IFS= read -r line; do
+    if [[ $line == "gitlab-license ("* ]]; then
+        RB_GEM_VERSION=${line#"gitlab-license ("}
+        RB_GEM_VERSION=${RB_GEM_VERSION%")"}
+        break
+    fi
+done <<< "$RB_GEM_LIST_OUTPUT"
+
+echo "[*] gitlab-license version: $RB_GEM_VERSION"
+RB_GEM_DOWNLOAD_URL="https://rubygems.org/downloads/gitlab-license-$RB_GEM_VERSION.gem"
+RB_GEM_DOWNLOAD_PATH=$(pwd)/temp/gem/gitlab-license.gem
+mkdir -p $(dirname $RB_GEM_DOWNLOAD_PATH)
+curl -L $RB_GEM_DOWNLOAD_URL -o $RB_GEM_DOWNLOAD_PATH
+pushd $(dirname $RB_GEM_DOWNLOAD_PATH) > /dev/null
+tar -xzf gitlab-license.gem
+tar -xzf data.tar.gz
+
+if [ ! -f "./lib/gitlab/license.rb" ]; then
+    echo "[!] failed to locate gem file, aborting..."
+    exit 1
+fi
+
+echo "[*] copying gem..."
+rm -rf "$WORKING_DIR/lib" || true
+mkdir -p "$WORKING_DIR/lib"
+cp -r ./lib/gitlab/* $WORKING_DIR/lib
+popd > /dev/null
+
+pushd lib > /dev/null
+echo "[*] patching lib requirements gem..."
+# replace `require 'gitlab/license/` with `require 'license/` to make it work
+find . -type f -exec sed -i '' 's/require '\''gitlab\/license\//require_relative '\''license\//g' {} \;
+popd > /dev/null
+
+echo "[*] updated gem"
+
+echo "[*] fetching gitlab source code..."
+GITLAB_SOURCE_CODE_DIR=$(pwd)/temp/src/
+if [ -d "$GITLAB_SOURCE_CODE_DIR" ]; then
+    echo "[*] gitlab source code already exists, skipping cloning..."
+else
+    echo "[*] cloning gitlab source code..."
+    git clone https://gitlab.com/gitlab-org/gitlab.git $GITLAB_SOURCE_CODE_DIR
+fi
+
+echo "[*] updating gitlab source code..."
+pushd $GITLAB_SOURCE_CODE_DIR > /dev/null
+git clean -fdx -f
+git reset --hard
+git pull
+popd > /dev/null
+
+echo "[*] scanning features..."
+FEATURE_LIST_FILE=$(pwd)/temp/features.txt
+rm -f $FEATURE_LIST_FILE || true
+./feature.scan.py $GITLAB_SOURCE_CODE_DIR $FEATURE_LIST_FILE
+
+echo "[*] generating license..."
+OUTPUT_DIR=$(pwd)/output
+mkdir -p $OUTPUT_DIR
+ruby ./generate_licenses.rb $OUTPUT_DIR $FEATURE_LIST_FILE
+
+echo "[*] done $(basename $0)"
\ No newline at end of file
diff --git a/result.gitlab-license b/result.gitlab-license
deleted file mode 100644
index 6b8ee3a..000000000
--- a/result.gitlab-license
+++ /dev/null
@@ -1,24 +0,0 @@
-eyJkYXRhIjoiOW5mNE9BaTBjYmxMendXbks4TGdDOWpDeVpNM1QzYzBNdzNs
-WS94WGlVR1o3UG9kNDNtWGlmSzJYcDNIXG5pWlc2UEhtVld0VFVUY3RabjF2
-Rk9wWXliZm1XUjM5dkxSQVhkVzJmcFBCQjd2eWwvY3kzaWF5dEdCZkxcblIx
-NWk4bmcvRlBpZ1Q2bXI1aFhoT1VKZm9xSHJ5RkE3NXV1b01IQkI0WHI4RGhl
-WVpsTEt6RmJueEZJdlxuRVkxZDk0Umd4d0dxcitqSDg0ZWMwKzhWcDFYaFEy
-NmhJWnpWMXRXWjY1Q2VVYVJ5TzJ2c2loeGhuRWRzXG5iOTVYWTZVaVJ6TlZs
-Ty8xaHByY3A1eklBVzBJQ0lwM2c3anR2SEtCWExuUkxnUDJucTN0UkhWNXM5
-T2dcbllmVkhseUZqZjRvclFpeGc1TEFVZmcwR0R6N0pDck9oc0xtWUZxTXQw
-SkZkamQ5YlhGU21OdzhkN2x4M1xuWU12MitXbS9zZ1ZiQzVFa1VJWExSaHlH
-bThjRjZNbEoya3N3MCttREVlNDFCem1ncHVWWWpyT01DQlJFXG56My9DSWRV
-dnFqY0ljTFFYYUdFajRTNmJtdjVxTXhYQTZiR3Bkd2orTVM4Y0doYjhGVENS
-UWVsRVlSVGVcbnZ1Z3lJdnZ6V2dYQWtCZk5NTU9Rd2JmMHFmOVJNK3FyN2lQ
-VXkxRWlYU2hDaHloTDhnV3BNc1FvVVNUNVxuSHZDcEE1Y2dPUmV1dC9YS1RH
-OHRIMFRJR2RmNjRDd3pFeENQKzN4QWJmM3IrSDJrZlhzaTFJWVhya25CXG5u
-aFhGTm83Q1doNUFJVWd1SmdnPVxuIiwia2V5IjoiT3huRG1YTEozcXVOZita
-K2lvU3RQMm5wa2U2K2ZMNVBpdEtJSkNkTUhNeTlHTmdhTVNoNnZlbERaUExz
-XG5JK3dJaHlEZ09vc2k0OEM4Tmp6Q29oL05mV3gybDJGRmxRSkFQLytRdGd4
-eDJiRnpFRlF5bk0zc0dnRUtcbkZRUkQzUGNTWkpzZGtXdkltWGEzWnlsMEg2
-WEtGelgrTnE0cGhqWktuQ1dneXk3dGU4YWI5Qm5ZNVBlYVxuWUNPL1I0SGpI
-MkhKTnhmamd2TWh0YThMNXgrbmt2RXhBODFIRDFsQlVXZzJlQi92RzZjblg0
-YkRPRWF3XG5tVHJpMS9VLzRVcVVoQnRSYklVSnZZeGFCMC9hT3owaStLVkdw
-SENSTCs3OXQveHA1NVg2bkRQWlhwdGdcbkE0WXJrbFVHUlF0RnZyMjRRMGxa
-TndrS2Z4eU1pOWkrclgrVzVIa1MvQT09XG4iLCJpdiI6Im1FL1RodjE4MWJQ
-eGNFaWVwdEhCWnc9PVxuIn0=