Add pages domains acme orderspages_lets_encrypt_orders

Extract acme double to helper

Create ACME challanges for pages domains

* Create order & challange through API
* save them to database
* request challenge validation

We're saving order and challenge as one entity,
that wouldn't be correct if we would order certificates for
several domains simultaneously, but we always order certificate
per domain

Add controller for processing acme challenges redirected from pages

Don't save acme challenge url - we don't use it

Validate acme challenge attributes

Encrypt private_key in acme orders

18 files changed, 552 insertions, 35 deletions

diff --git a/app/controllers/acme_challenges_controller.rb b/app/controllers/acme_challenges_controller.rb
new file mode 100644
index 00000000000..67a39d8870b
--- /dev/null
+++ b/app/controllers/acme_challenges_controller.rb
@@ -0,0 +1,17 @@
+# frozen_string_literal: true
+
+class AcmeChallengesController < ActionController::Base
+  def show
+    if acme_order
+      render plain: acme_order.challenge_file_content, content_type: 'text/plain'
+    else
+      head :not_found
+    end
+  end
+
+  private
+
+  def acme_order
+    @acme_order ||= PagesDomainAcmeOrder.find_by_domain_and_token(params[:domain], params[:token])
+  end
+end
diff --git a/app/models/pages_domain.rb b/app/models/pages_domain.rb
index 407d85b1520..5c3441791fd 100644
--- a/app/models/pages_domain.rb
+++ b/app/models/pages_domain.rb
@@ -5,6 +5,7 @@ class PagesDomain < ApplicationRecord
   VERIFICATION_THRESHOLD = 3.days.freeze
 
   belongs_to :project
+  has_many :acme_orders, class_name: "PagesDomainAcmeOrder"
 
   validates :domain, hostname: { allow_numeric_hostname: true }
   validates :domain, uniqueness: { case_sensitive: false }
diff --git a/app/models/pages_domain_acme_order.rb b/app/models/pages_domain_acme_order.rb
new file mode 100644
index 00000000000..63d7fbc8206
--- /dev/null
+++ b/app/models/pages_domain_acme_order.rb
@@ -0,0 +1,24 @@
+# frozen_string_literal: true
+
+class PagesDomainAcmeOrder < ApplicationRecord
+  belongs_to :pages_domain
+
+  scope :expired, -> { where("expires_at < ?", Time.now) }
+
+  validates :pages_domain, presence: true
+  validates :expires_at, presence: true
+  validates :url, presence: true
+  validates :challenge_token, presence: true
+  validates :challenge_file_content, presence: true
+  validates :private_key, presence: true
+
+  attr_encrypted :private_key,
+                 mode: :per_attribute_iv,
+                 key: Settings.attr_encrypted_db_key_base_truncated,
+                 algorithm: 'aes-256-gcm',
+                 encode: true
+
+  def self.find_by_domain_and_token(domain_name, challenge_token)
+    joins(:pages_domain).find_by(pages_domains: { domain: domain_name }, challenge_token: challenge_token)
+  end
+end
diff --git a/app/services/pages_domains/create_acme_order_service.rb b/app/services/pages_domains/create_acme_order_service.rb
new file mode 100644
index 00000000000..c600f497fa5
--- /dev/null
+++ b/app/services/pages_domains/create_acme_order_service.rb
@@ -0,0 +1,31 @@
+# frozen_string_literal: true
+
+module PagesDomains
+  class CreateAcmeOrderService
+    attr_reader :pages_domain
+
+    def initialize(pages_domain)
+      @pages_domain = pages_domain
+    end
+
+    def execute
+      lets_encrypt_client = Gitlab::LetsEncrypt::Client.new
+      order = lets_encrypt_client.new_order(pages_domain.domain)
+
+      challenge = order.new_challenge
+
+      private_key = OpenSSL::PKey::RSA.new(4096)
+      saved_order = pages_domain.acme_orders.create!(
+        url: order.url,
+        expires_at: order.expires,
+        private_key: private_key.to_pem,
+
+        challenge_token: challenge.token,
+        challenge_file_content: challenge.file_content
+      )
+
+      challenge.request_validation
+      saved_order
+    end
+  end
+end
diff --git a/app/services/pages_domains/obtain_lets_encrypt_certificate_service.rb b/app/services/pages_domains/obtain_lets_encrypt_certificate_service.rb
new file mode 100644
index 00000000000..2dfe1a3d8ca
--- /dev/null
+++ b/app/services/pages_domains/obtain_lets_encrypt_certificate_service.rb
@@ -0,0 +1,41 @@
+# frozen_string_literal: true
+
+module PagesDomains
+  class ObtainLetsEncryptCertificateService
+    attr_reader :pages_domain
+
+    def initialize(pages_domain)
+      @pages_domain = pages_domain
+    end
+
+    def execute
+      pages_domain.acme_orders.expired.delete_all
+      acme_order = pages_domain.acme_orders.first
+
+      unless acme_order
+        ::PagesDomains::CreateAcmeOrderService.new(pages_domain).execute
+        return
+      end
+
+      api_order = ::Gitlab::LetsEncrypt::Client.new.load_order(acme_order.url)
+
+      # https://tools.ietf.org/html/rfc8555#section-7.1.6 - statuses diagram
+      case api_order.status
+      when 'ready'
+        api_order.request_certificate(private_key: acme_order.private_key, domain: pages_domain.domain)
+      when 'valid'
+        save_certificate(acme_order.private_key, api_order)
+        acme_order.destroy!
+        # when 'invalid'
+        # TODO: implement error handling
+      end
+    end
+
+    private
+
+    def save_certificate(private_key, api_order)
+      certificate = api_order.certificate
+      pages_domain.update!(key: private_key, certificate: certificate)
+    end
+  end
+end
diff --git a/config/routes.rb b/config/routes.rb
index f5957f43655..cb90a0134c4 100644
--- a/config/routes.rb
+++ b/config/routes.rb
@@ -75,6 +75,8 @@ Rails.application.routes.draw do
       resources :issues, module: :boards, only: [:index, :update]
     end
 
+    get 'acme-challenge/' => 'acme_challenges#show'
+
     # UserCallouts
     resources :user_callouts, only: [:create]
 
diff --git a/db/migrate/20190429082448_create_pages_domain_acme_orders.rb b/db/migrate/20190429082448_create_pages_domain_acme_orders.rb
new file mode 100644
index 00000000000..af811e83518
--- /dev/null
+++ b/db/migrate/20190429082448_create_pages_domain_acme_orders.rb
@@ -0,0 +1,28 @@
+# frozen_string_literal: true
+
+# See http://doc.gitlab.com/ce/development/migration_style_guide.html
+# for more information on how to write migrations for GitLab.
+
+class CreatePagesDomainAcmeOrders < ActiveRecord::Migration[5.1]
+  include Gitlab::Database::MigrationHelpers
+
+  # Set this constant to true if this migration requires downtime.
+  DOWNTIME = false
+
+  def change
+    create_table :pages_domain_acme_orders do |t|
+      t.references :pages_domain, null: false, index: true, foreign_key: { on_delete: :cascade }, type: :integer
+
+      t.datetime_with_timezone :expires_at, null: false
+      t.timestamps_with_timezone null: false
+
+      t.string :url, null: false
+
+      t.string :challenge_token, null: false, index: true
+      t.text :challenge_file_content, null: false
+
+      t.text :encrypted_private_key, null: false
+      t.text :encrypted_private_key_iv, null: false
+    end
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index fcf9e397ac1..59e9429b819 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -1571,6 +1571,20 @@ ActiveRecord::Schema.define(version: 20190530154715) do
     t.index ["access_grant_id"], name: "index_oauth_openid_requests_on_access_grant_id", using: :btree
   end
 
+  create_table "pages_domain_acme_orders", force: :cascade do |t|
+    t.integer "pages_domain_id", null: false
+    t.datetime_with_timezone "expires_at", null: false
+    t.datetime_with_timezone "created_at", null: false
+    t.datetime_with_timezone "updated_at", null: false
+    t.string "url", null: false
+    t.string "challenge_token", null: false
+    t.text "challenge_file_content", null: false
+    t.text "encrypted_private_key", null: false
+    t.text "encrypted_private_key_iv", null: false
+    t.index ["challenge_token"], name: "index_pages_domain_acme_orders_on_challenge_token", using: :btree
+    t.index ["pages_domain_id"], name: "index_pages_domain_acme_orders_on_pages_domain_id", using: :btree
+  end
+
   create_table "pages_domains", id: :serial, force: :cascade do |t|
     t.integer "project_id"
     t.text "certificate"
@@ -2560,6 +2574,7 @@ ActiveRecord::Schema.define(version: 20190530154715) do
   add_foreign_key "notes", "projects", name: "fk_99e097b079", on_delete: :cascade
   add_foreign_key "notification_settings", "users", name: "fk_0c95e91db7", on_delete: :cascade
   add_foreign_key "oauth_openid_requests", "oauth_access_grants", column: "access_grant_id", name: "fk_oauth_openid_requests_oauth_access_grants_access_grant_id"
+  add_foreign_key "pages_domain_acme_orders", "pages_domains", on_delete: :cascade
   add_foreign_key "pages_domains", "projects", name: "fk_ea2f6dfc6f", on_delete: :cascade
   add_foreign_key "personal_access_tokens", "users"
   add_foreign_key "pool_repositories", "projects", column: "source_project_id", on_delete: :nullify
diff --git a/lib/gitlab/lets_encrypt/challenge.rb b/lib/gitlab/lets_encrypt/challenge.rb
index 6a7f5e965c5..136268c974b 100644
--- a/lib/gitlab/lets_encrypt/challenge.rb
+++ b/lib/gitlab/lets_encrypt/challenge.rb
@@ -7,7 +7,7 @@ module Gitlab
         @acme_challenge = acme_challenge
       end
 
-      delegate :url, :token, :file_content, :status, :request_validation, to: :acme_challenge
+      delegate :token, :file_content, :status, :request_validation, to: :acme_challenge
 
       private
 
diff --git a/lib/gitlab/lets_encrypt/order.rb b/lib/gitlab/lets_encrypt/order.rb
index 5109b5e9843..9c2365f98a8 100644
--- a/lib/gitlab/lets_encrypt/order.rb
+++ b/lib/gitlab/lets_encrypt/order.rb
@@ -13,7 +13,16 @@ module Gitlab
         ::Gitlab::LetsEncrypt::Challenge.new(challenge)
       end
 
-      delegate :url, :status, to: :acme_order
+      def request_certificate(domain:, private_key:)
+        csr = ::Acme::Client::CertificateRequest.new(
+          private_key: OpenSSL::PKey.read(private_key),
+          subject: { common_name: domain }
+        )
+
+        acme_order.finalize(csr: csr)
+      end
+
+      delegate :url, :status, :expires, :certificate, to: :acme_order
 
       private
 
diff --git a/spec/controllers/acme_challenges_controller_spec.rb b/spec/controllers/acme_challenges_controller_spec.rb
new file mode 100644
index 00000000000..cee06bed27b
--- /dev/null
+++ b/spec/controllers/acme_challenges_controller_spec.rb
@@ -0,0 +1,44 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe AcmeChallengesController do
+  describe '#show' do
+    let!(:acme_order) { create(:pages_domain_acme_order) }
+
+    def make_request(domain, token)
+      get(:show, params: { domain: domain, token: token })
+    end
+
+    before do
+      make_request(domain, token)
+    end
+
+    context 'with right domain and token' do
+      let(:domain) { acme_order.pages_domain.domain }
+      let(:token) { acme_order.challenge_token }
+
+      it 'renders acme challenge file content' do
+        expect(response.body).to eq(acme_order.challenge_file_content)
+      end
+    end
+
+    context 'when domain is invalid' do
+      let(:domain) { 'somewrongdomain.com' }
+      let(:token) { acme_order.challenge_token }
+
+      it 'renders not found' do
+        expect(response).to have_gitlab_http_status(404)
+      end
+    end
+
+    context 'when token is invalid' do
+      let(:domain) { acme_order.pages_domain.domain }
+      let(:token) { 'wrongtoken' }
+
+      it 'renders not found' do
+        expect(response).to have_gitlab_http_status(404)
+      end
+    end
+  end
+end
diff --git a/spec/factories/pages_domain_acme_orders.rb b/spec/factories/pages_domain_acme_orders.rb
new file mode 100644
index 00000000000..7f9ee1c8f9c
--- /dev/null
+++ b/spec/factories/pages_domain_acme_orders.rb
@@ -0,0 +1,17 @@
+# frozen_string_literal: true
+
+FactoryBot.define do
+  factory :pages_domain_acme_order do
+    pages_domain
+    url { 'https://example.com/' }
+    expires_at { 1.day.from_now }
+    challenge_token { 'challenge_token' }
+    challenge_file_content { 'filecontent' }
+
+    private_key { OpenSSL::PKey::RSA.new(4096).to_pem }
+
+    trait :expired do
+      expires_at { 1.day.ago }
+    end
+  end
+end
diff --git a/spec/lib/gitlab/lets_encrypt/challenge_spec.rb b/spec/lib/gitlab/lets_encrypt/challenge_spec.rb
index 74622f356de..fcd92586362 100644
--- a/spec/lib/gitlab/lets_encrypt/challenge_spec.rb
+++ b/spec/lib/gitlab/lets_encrypt/challenge_spec.rb
@@ -3,23 +3,11 @@
 require 'spec_helper'
 
 describe ::Gitlab::LetsEncrypt::Challenge do
-  delegated_methods = {
-    url: 'https://example.com/',
-    status: 'pending',
-    token: 'tokenvalue',
-    file_content: 'hereisfilecontent',
-    request_validation: true
-  }
+  include LetsEncryptHelpers
 
-  let(:acme_challenge) do
-    acme_challenge = instance_double('Acme::Client::Resources::Challenge')
-    allow(acme_challenge).to receive_messages(delegated_methods)
-    acme_challenge
-  end
-
-  let(:challenge) { described_class.new(acme_challenge) }
+  let(:challenge) { described_class.new(acme_challenge_double) }
 
-  delegated_methods.each do |method, value|
+  LetsEncryptHelpers::ACME_CHALLENGE_METHODS.each do |method, value|
     describe "##{method}" do
       it 'delegates to Acme::Client::Resources::Challenge' do
         expect(challenge.public_send(method)).to eq(value)
diff --git a/spec/lib/gitlab/lets_encrypt/order_spec.rb b/spec/lib/gitlab/lets_encrypt/order_spec.rb
index ee7058baf8d..1a759103c44 100644
--- a/spec/lib/gitlab/lets_encrypt/order_spec.rb
+++ b/spec/lib/gitlab/lets_encrypt/order_spec.rb
@@ -3,20 +3,13 @@
 require 'spec_helper'
 
 describe ::Gitlab::LetsEncrypt::Order do
-  delegated_methods = {
-    url: 'https://example.com/',
-    status: 'valid'
-  }
-
-  let(:acme_order) do
-    acme_order = instance_double('Acme::Client::Resources::Order')
-    allow(acme_order).to receive_messages(delegated_methods)
-    acme_order
-  end
+  include LetsEncryptHelpers
+
+  let(:acme_order) { acme_order_double }
 
   let(:order) { described_class.new(acme_order) }
 
-  delegated_methods.each do |method, value|
+  LetsEncryptHelpers::ACME_ORDER_METHODS.each do |method, value|
     describe "##{method}" do
       it 'delegates to Acme::Client::Resources::Order' do
         expect(order.public_send(method)).to eq(value)
@@ -25,15 +18,24 @@ describe ::Gitlab::LetsEncrypt::Order do
   end
 
   describe '#new_challenge' do
-    before do
-      challenge = instance_double('Acme::Client::Resources::Challenges::HTTP01')
-      authorization = instance_double('Acme::Client::Resources::Authorization')
-      allow(authorization).to receive(:http).and_return(challenge)
-      allow(acme_order).to receive(:authorizations).and_return([authorization])
-    end
-
     it 'returns challenge' do
       expect(order.new_challenge).to be_a(::Gitlab::LetsEncrypt::Challenge)
     end
   end
+
+  describe '#request_certificate' do
+    let(:private_key) do
+      OpenSSL::PKey::RSA.new(4096).to_pem
+    end
+
+    it 'generates csr and finalizes order' do
+      expect(acme_order).to receive(:finalize) do |csr:|
+        expect do
+          csr.csr # it's being evaluated lazily
+        end.not_to raise_error
+      end
+
+      order.request_certificate(domain: 'example.com', private_key: private_key)
+    end
+  end
 end
diff --git a/spec/models/pages_domain_acme_order_spec.rb b/spec/models/pages_domain_acme_order_spec.rb
new file mode 100644
index 00000000000..4ffb4fc7389
--- /dev/null
+++ b/spec/models/pages_domain_acme_order_spec.rb
@@ -0,0 +1,49 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe PagesDomainAcmeOrder do
+  using RSpec::Parameterized::TableSyntax
+
+  describe '.expired' do
+    let!(:not_expired_order) { create(:pages_domain_acme_order) }
+    let!(:expired_order) { create(:pages_domain_acme_order, :expired) }
+
+    it 'returns only expired orders' do
+      expect(described_class.count).to eq(2)
+      expect(described_class.expired).to eq([expired_order])
+    end
+  end
+
+  describe '.find_by_domain_and_token' do
+    let!(:domain) { create(:pages_domain, domain: 'test.com') }
+    let!(:acme_order) { create(:pages_domain_acme_order, challenge_token: 'righttoken', pages_domain: domain) }
+
+    where(:domain_name, :challenge_token, :present) do
+      'test.com' | 'righttoken' | true
+      'test.com' | 'wrongtoken' | false
+      'test.org' | 'righttoken' | false
+    end
+
+    with_them do
+      subject { described_class.find_by_domain_and_token(domain_name, challenge_token).present? }
+
+      it { is_expected.to eq(present) }
+    end
+  end
+
+  subject { create(:pages_domain_acme_order) }
+
+  describe 'associations' do
+    it { is_expected.to belong_to(:pages_domain) }
+  end
+
+  describe 'validations' do
+    it { is_expected.to validate_presence_of(:pages_domain) }
+    it { is_expected.to validate_presence_of(:expires_at) }
+    it { is_expected.to validate_presence_of(:url) }
+    it { is_expected.to validate_presence_of(:challenge_token) }
+    it { is_expected.to validate_presence_of(:challenge_file_content) }
+    it { is_expected.to validate_presence_of(:private_key) }
+  end
+end
diff --git a/spec/services/pages_domains/create_acme_order_service_spec.rb b/spec/services/pages_domains/create_acme_order_service_spec.rb
new file mode 100644
index 00000000000..d59aa9b979e
--- /dev/null
+++ b/spec/services/pages_domains/create_acme_order_service_spec.rb
@@ -0,0 +1,63 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe PagesDomains::CreateAcmeOrderService do
+  include LetsEncryptHelpers
+
+  let(:pages_domain) { create(:pages_domain) }
+
+  let(:challenge) { ::Gitlab::LetsEncrypt::Challenge.new(acme_challenge_double) }
+
+  let(:order_double) do
+    Gitlab::LetsEncrypt::Order.new(acme_order_double).tap do |order|
+      allow(order).to receive(:new_challenge).and_return(challenge)
+    end
+  end
+
+  let(:lets_encrypt_client) do
+    instance_double('Gitlab::LetsEncrypt::Client').tap do |client|
+      allow(client).to receive(:new_order).with(pages_domain.domain)
+        .and_return(order_double)
+    end
+  end
+
+  let(:service) { described_class.new(pages_domain) }
+
+  before do
+    allow(::Gitlab::LetsEncrypt::Client).to receive(:new).and_return(lets_encrypt_client)
+  end
+
+  it 'saves order to database before requesting validation' do
+    allow(pages_domain.acme_orders).to receive(:create!).and_call_original
+    allow(challenge).to receive(:request_validation).and_call_original
+
+    service.execute
+
+    expect(pages_domain.acme_orders).to have_received(:create!).ordered
+    expect(challenge).to have_received(:request_validation).ordered
+  end
+
+  it 'generates and saves private key' do
+    service.execute
+
+    saved_order = PagesDomainAcmeOrder.last
+    expect { OpenSSL::PKey::RSA.new(saved_order.private_key) }.not_to raise_error
+  end
+
+  it 'properly saves order attributes' do
+    service.execute
+
+    saved_order = PagesDomainAcmeOrder.last
+    expect(saved_order.url).to eq(order_double.url)
+    expect(saved_order.expires_at).to be_like_time(order_double.expires)
+  end
+
+  it 'properly saves challenge attributes' do
+    service.execute
+
+    saved_order = PagesDomainAcmeOrder.last
+    expect(saved_order.challenge_token).to eq(challenge.token)
+    expect(saved_order.challenge_file_content).to eq(challenge.file_content)
+  end
+end
diff --git a/spec/services/pages_domains/obtain_lets_encrypt_certificate_service_spec.rb b/spec/services/pages_domains/obtain_lets_encrypt_certificate_service_spec.rb
new file mode 100644
index 00000000000..6d7be27939c
--- /dev/null
+++ b/spec/services/pages_domains/obtain_lets_encrypt_certificate_service_spec.rb
@@ -0,0 +1,146 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe PagesDomains::ObtainLetsEncryptCertificateService do
+  include LetsEncryptHelpers
+
+  let(:pages_domain) { create(:pages_domain, :without_certificate, :without_key) }
+  let(:service) { described_class.new(pages_domain) }
+
+  before do
+    stub_lets_encrypt_settings
+  end
+
+  def expect_to_create_acme_challenge
+    expect(::PagesDomains::CreateAcmeOrderService).to receive(:new).with(pages_domain)
+      .and_wrap_original do |m, *args|
+      create_service = m.call(*args)
+
+      expect(create_service).to receive(:execute)
+
+      create_service
+    end
+  end
+
+  def stub_lets_encrypt_order(url, status)
+    order = ::Gitlab::LetsEncrypt::Order.new(acme_order_double(status: status))
+
+    allow_any_instance_of(::Gitlab::LetsEncrypt::Client).to(
+      receive(:load_order).with(url).and_return(order)
+    )
+
+    order
+  end
+
+  context 'when there is no acme order' do
+    it 'creates acme order' do
+      expect_to_create_acme_challenge
+
+      service.execute
+    end
+  end
+
+  context 'when there is expired acme order' do
+    let!(:existing_order) do
+      create(:pages_domain_acme_order, :expired, pages_domain: pages_domain)
+    end
+
+    it 'removes acme order and creates new one' do
+      expect_to_create_acme_challenge
+
+      service.execute
+
+      expect(PagesDomainAcmeOrder.find_by_id(existing_order.id)).to be_nil
+    end
+  end
+
+  %w(pending processing).each do |status|
+    context "there is an order in '#{status}' status" do
+      let(:existing_order) do
+        create(:pages_domain_acme_order, pages_domain: pages_domain)
+      end
+
+      before do
+        stub_lets_encrypt_order(existing_order.url, status)
+      end
+
+      it 'does not raise errors' do
+        expect do
+          service.execute
+        end.not_to raise_error
+      end
+    end
+  end
+
+  context 'when order is ready' do
+    let(:existing_order) do
+      create(:pages_domain_acme_order, pages_domain: pages_domain)
+    end
+
+    let!(:api_order) do
+      stub_lets_encrypt_order(existing_order.url, 'ready')
+    end
+
+    it 'request certificate' do
+      expect(api_order).to receive(:request_certificate).and_call_original
+
+      service.execute
+    end
+  end
+
+  context 'when order is valid' do
+    let(:existing_order) do
+      create(:pages_domain_acme_order, pages_domain: pages_domain)
+    end
+
+    let!(:api_order) do
+      stub_lets_encrypt_order(existing_order.url, 'valid')
+    end
+
+    let(:certificate) do
+      key = OpenSSL::PKey.read(existing_order.private_key)
+
+      subject = "/C=BE/O=Test/OU=Test/CN=#{pages_domain.domain}"
+
+      cert = OpenSSL::X509::Certificate.new
+      cert.subject = cert.issuer = OpenSSL::X509::Name.parse(subject)
+      cert.not_before = Time.now
+      cert.not_after = 1.year.from_now
+      cert.public_key = key.public_key
+      cert.serial = 0x0
+      cert.version = 2
+
+      ef = OpenSSL::X509::ExtensionFactory.new
+      ef.subject_certificate = cert
+      ef.issuer_certificate = cert
+      cert.extensions = [
+        ef.create_extension("basicConstraints", "CA:TRUE", true),
+        ef.create_extension("subjectKeyIdentifier", "hash")
+      ]
+      cert.add_extension ef.create_extension("authorityKeyIdentifier",
+                                             "keyid:always,issuer:always")
+
+      cert.sign key, OpenSSL::Digest::SHA1.new
+
+      cert.to_pem
+    end
+
+    before do
+      expect(api_order).to receive(:certificate) { certificate }
+    end
+
+    it 'saves private_key and certificate for domain' do
+      service.execute
+
+      expect(pages_domain.key).to be_present
+      expect(pages_domain.certificate).to eq(certificate)
+    end
+
+    it 'removes order from database' do
+      service.execute
+
+      expect(PagesDomainAcmeOrder.find_by_id(existing_order.id)).to be_nil
+    end
+  end
+end
diff --git a/spec/support/helpers/lets_encrypt_helpers.rb b/spec/support/helpers/lets_encrypt_helpers.rb
index 7f0886b451c..2857416ad95 100644
--- a/spec/support/helpers/lets_encrypt_helpers.rb
+++ b/spec/support/helpers/lets_encrypt_helpers.rb
@@ -1,6 +1,26 @@
 # frozen_string_literal: true
 
 module LetsEncryptHelpers
+  ACME_ORDER_METHODS = {
+    url: 'https://example.com/',
+    status: 'valid',
+    expires: 2.days.from_now
+  }.freeze
+
+  ACME_CHALLENGE_METHODS = {
+    status: 'pending',
+    token: 'tokenvalue',
+    file_content: 'hereisfilecontent',
+    request_validation: true
+  }.freeze
+
+  def stub_lets_encrypt_settings
+    stub_application_setting(
+      lets_encrypt_notification_email: 'myemail@test.example.com',
+      lets_encrypt_terms_of_service_accepted: true
+    )
+  end
+
   def stub_lets_encrypt_client
     client = instance_double('Acme::Client')
 
@@ -16,4 +36,24 @@ module LetsEncryptHelpers
 
     client
   end
+
+  def acme_challenge_double
+    challenge = instance_double('Acme::Client::Resources::Challenges::HTTP01')
+    allow(challenge).to receive_messages(ACME_CHALLENGE_METHODS)
+    challenge
+  end
+
+  def acme_authorization_double
+    authorization = instance_double('Acme::Client::Resources::Authorization')
+    allow(authorization).to receive(:http).and_return(acme_challenge_double)
+    authorization
+  end
+
+  def acme_order_double(attributes = {})
+    acme_order = instance_double('Acme::Client::Resources::Order')
+    allow(acme_order).to receive_messages(ACME_ORDER_METHODS.merge(attributes))
+    allow(acme_order).to receive(:authorizations).and_return([acme_authorization_double])
+    allow(acme_order).to receive(:finalize)
+    acme_order
+  end
 end