Revert "Revert "Add encrypted secrets""

railties/lib/rails/application.rb

@@ -4,6 +4,7 @@ require "active_support/core_ext/object/blank"
 require "active_support/key_generator"
 require "active_support/message_verifier"
 require "rails/engine"
+require "rails/secrets"
 
 module Rails
   # An Engine with the responsibility of coordinating the whole boot process.
@@ -385,18 +386,7 @@ module Rails
     def secrets
       @secrets ||= begin
         secrets = ActiveSupport::OrderedOptions.new
-        yaml    = config.paths["config/secrets"].first
-
-        if File.exist?(yaml)
-          require "erb"
-
-          all_secrets    = YAML.load(ERB.new(IO.read(yaml)).result) || {}
-          shared_secrets = all_secrets["shared"]
-          env_secrets    = all_secrets[Rails.env]
-
-          secrets.merge!(shared_secrets.deep_symbolize_keys) if shared_secrets
-          secrets.merge!(env_secrets.deep_symbolize_keys) if env_secrets
-        end
+        secrets.merge! Rails::Secrets.parse(config.paths["config/secrets"].existent, env: Rails.env)
 
         # Fallback to config.secret_key_base if secrets.secret_key_base isn't set
         secrets.secret_key_base ||= config.secret_key_base

railties/lib/rails/application/bootstrap.rb

@@ -2,6 +2,7 @@ require "fileutils"
 require "active_support/notifications"
 require "active_support/dependencies"
 require "active_support/descendants_tracker"
+require "rails/secrets"
 
 module Rails
   class Application
@@ -77,6 +78,11 @@ INFO
       initializer :bootstrap_hook, group: :all do |app|
         ActiveSupport.run_load_hooks(:before_initialize, app)
       end
+
+      initializer :set_secrets_root, group: :all do
+        Rails::Secrets.root = root
+        Rails::Secrets.read_encrypted_secrets = config.read_encrypted_secrets
+      end
     end
   end
 end

railties/lib/rails/application/configuration.rb

@@ -13,7 +13,8 @@ module Rails
                     :railties_order, :relative_url_root, :secret_key_base, :secret_token,
                     :ssl_options, :public_file_server,
                     :session_options, :time_zone, :reload_classes_only_on_change,
-                    :beginning_of_week, :filter_redirect, :x, :enable_dependency_loading
+                    :beginning_of_week, :filter_redirect, :x, :enable_dependency_loading,
+                    :read_encrypted_secrets
 
       attr_writer :log_level
       attr_reader :encoding, :api_only
@@ -51,6 +52,7 @@ module Rails
         @debug_exception_response_format = nil
         @x                               = Custom.new
         @enable_dependency_loading       = false
+        @read_encrypted_secrets          = false
       end
 
       def encoding=(value)
@@ -80,7 +82,7 @@ module Rails
         @paths ||= begin
           paths = super
           paths.add "config/database",    with: "config/database.yml"
-          paths.add "config/secrets",     with: "config/secrets.yml"
+          paths.add "config/secrets",     with: "config", glob: "secrets.yml{,.enc}"
           paths.add "config/environment", with: "config/environment.rb"
           paths.add "lib/templates"
           paths.add "log",                with: "log/#{Rails.env}.log"

railties/lib/rails/command.rb

@@ -27,15 +27,22 @@ module Rails
       end
 
       # Receives a namespace, arguments and the behavior to invoke the command.
-      def invoke(namespace, args = [], **config)
-        namespace = namespace.to_s
-        namespace = "help" if namespace.blank? || HELP_MAPPINGS.include?(namespace)
-        namespace = "version" if %w( -v --version ).include? namespace
+      def invoke(full_namespace, args = [], **config)
+        namespace = full_namespace = full_namespace.to_s
 
-        if command = find_by_namespace(namespace)
-          command.perform(namespace, args, config)
+        if char = namespace =~ /:(\w+)$/
+          command_name, namespace = $1, namespace.slice(0, char)
         else
-          find_by_namespace("rake").perform(namespace, args, config)
+          command_name = namespace
+        end
+
+        command_name = "help" if command_name.blank? || HELP_MAPPINGS.include?(command_name)
+        namespace = "version" if %w( -v --version ).include?(command_name)
+
+        if command = find_by_namespace(namespace, command_name)
+          command.perform(command_name, args, config)
+        else
+          find_by_namespace("rake").perform(full_namespace, args, config)
         end
       end
 
@@ -52,8 +59,10 @@ module Rails
       #
       # Notice that "rails:commands:webrat" could be loaded as well, what
       # Rails looks for is the first and last parts of the namespace.
-      def find_by_namespace(name) # :nodoc:
-        lookups = [ name, "rails:#{name}" ]
+      def find_by_namespace(namespace, command_name = nil) # :nodoc:
+        lookups = [ namespace ]
+        lookups << "#{namespace}:#{command_name}" if command_name
+        lookups.concat lookups.map { |lookup| "rails:#{lookup}" }
 
         lookup(lookups)
 

railties/lib/rails/command/base.rb

@@ -56,7 +56,9 @@ module Rails
         end
 
         def perform(command, args, config) # :nodoc:
-          command = nil if Rails::Command::HELP_MAPPINGS.include?(args.first)
+          if Rails::Command::HELP_MAPPINGS.include?(args.first)
+            command, args = "help", []
+          end
 
           dispatch(command, args.dup, nil, config)
         end
@@ -111,7 +113,7 @@ module Rails
         # For a `Rails::Command::TestCommand` placed in `rails/command/test_command.rb`
         # would return `rails/test`.
         def default_command_root
-          path = File.expand_path(File.join("../commands", command_name), __dir__)
+          path = File.expand_path(File.join("../commands", command_root_namespace), __dir__)
           path if File.exist?(path)
         end
 
@@ -129,6 +131,10 @@ module Rails
               super
             end
           end
+
+          def command_root_namespace
+            (namespace.split(":") - %w( rails )).first
+          end
       end
 
       def help

railties/lib/rails/commands/secrets/USAGE

@@ -0,0 +1,52 @@
+=== Storing Encrypted Secrets in Source Control
+
+The Rails `secrets` commands helps encrypting secrets to slim a production
+environment's `ENV` hash. It's also useful for atomic deploys: no need to
+coordinate key changes to get everything working as the keys are shipped
+with the code.
+
+=== Setup
+
+Run `bin/rails secrets:setup` to opt in and generate the `config/secrets.yml.key`
+and `config/secrets.yml.enc` files.
+
+The latter contains all the keys to be encrypted while the former holds the
+encryption key.
+
+Don't lose the key! Put it in a password manager your team can access.
+Should you lose it no one, including you, will be able to access any encrypted
+secrets.
+Don't commit the key! Add `config/secrets.yml.key` to your source control's
+ignore file. If you use Git, Rails handles this for you.
+
+Rails also looks for the key in `ENV["RAILS_MASTER_KEY"]` if that's easier to
+manage.
+
+You could prepend that to your server's start command like this:
+
+   RAILS_MASTER_KEY="im-the-master-now-hahaha" server.start
+
+
+The `config/secrets.yml.enc` has much the same format as `config/secrets.yml`:
+
+   production:
+     secret_key_base: so-secret-very-hidden-wow
+     payment_processing_gateway_key: much-safe-very-gaedwey-wow
+
+But that's where the similarities between `secrets.yml` and `secrets.yml.enc`
+end, e.g. no keys from `secrets.yml` will be moved to `secrets.yml.enc` and
+be encrypted.
+
+A `shared:` top level key is also supported such that any keys there is merged
+into the other environments.
+
+=== Editing Secrets
+
+After `bin/rails secrets:setup`, run `bin/rails secrets:edit`.
+
+That command opens a temporary file in `$EDITOR` with the decrypted contents of
+`config/secrets.yml.enc` to edit the encrypted secrets.
+
+When the temporary file is next saved the contents are encrypted and written to
+`config/secrets.yml.enc` while the file itself is destroyed to prevent secrets
+from leaking.

railties/lib/rails/commands/secrets/secrets_command.rb

@@ -0,0 +1,50 @@
+require "active_support"
+require "rails/secrets"
+
+module Rails
+  module Command
+    class SecretsCommand < Rails::Command::Base # :nodoc:
+      def help
+        say "Usage:\n  #{self.class.banner}"
+        say ""
+        say self.class.desc
+      end
+
+      def setup
+        require "rails/generators"
+        require "rails/generators/rails/encrypted_secrets/encrypted_secrets_generator"
+
+        Rails::Generators::EncryptedSecretsGenerator.start
+      end
+
+      def edit
+        require_application_and_environment!
+
+        Rails::Secrets.read_for_editing do |tmp_path|
+          watch tmp_path do
+            puts "Waiting for secrets file to be saved. Abort with Ctrl-C."
+            system("\$EDITOR #{tmp_path}")
+          end
+        end
+
+        puts "New secrets encrypted and saved."
+      rescue Interrupt
+        puts "Aborted changing encrypted secrets: nothing saved."
+      rescue Rails::Secrets::MissingKeyError => error
+        say error.message
+      end
+
+      private
+        def watch(tmp_path)
+          mtime, start_time = File.mtime(tmp_path), Time.now
+
+          yield
+
+          editor_exits_after_open = $?.success? && (Time.now - start_time) < 1
+          if editor_exits_after_open
+            sleep 0.250 until File.mtime(tmp_path) != mtime
+          end
+        end
+    end
+  end
+end

railties/lib/rails/generators.rb

@@ -214,6 +214,7 @@ module Rails
         rails.map! { |n| n.sub(/^rails:/, "") }
         rails.delete("app")
         rails.delete("plugin")
+        rails.delete("encrypted_secrets")
 
         hidden_namespaces.each { |n| groups.delete(n.to_s) }
 

railties/lib/rails/generators/rails/app/templates/config/environments/production.rb.tt

@@ -14,6 +14,11 @@ Rails.application.configure do
   config.consider_all_requests_local       = false
   config.action_controller.perform_caching = true
 
+  # Attempt to read encrypted secrets from `config/secrets.yml.enc`.
+  # Requires an encryption key in `ENV["RAILS_MASTER_KEY"]` or
+  # `config/secrets.yml.key`.
+  config.read_encrypted_secrets = true
+
   # Disable serving static files from the `/public` folder by default since
   # Apache or NGINX already handles this.
   config.public_file_server.enabled = ENV['RAILS_SERVE_STATIC_FILES'].present?

railties/lib/rails/generators/rails/app/templates/config/secrets.yml

@@ -23,8 +23,10 @@ development:
 test:
   secret_key_base: <%= app_secret %>
 
-# Do not keep production secrets in the repository,
-# instead read values from the environment.
+# Do not keep production secrets in the unencrypted secrets file.
+# Instead, either read values from the environment.
+# Or, use `bin/rails secrets:setup` to configure encrypted secrets
+# and move the `production:` environment over there.
 
 production:
   secret_key_base: <%%= ENV["SECRET_KEY_BASE"] %>

railties/lib/rails/generators/rails/encrypted_secrets/encrypted_secrets_generator.rb

@@ -0,0 +1,66 @@
+require "rails/generators/base"
+require "rails/secrets"
+
+module Rails
+  module Generators
+    class EncryptedSecretsGenerator < Base
+      def add_secrets_key_file
+        unless File.exist?("config/secrets.yml.key") || File.exist?("config/secrets.yml.enc")
+          key = Rails::Secrets.generate_key
+
+          say "Adding config/secrets.yml.key to store the encryption key: #{key}"
+          say ""
+          say "Save this in a password manager your team can access."
+          say ""
+          say "If you lose the key, no one, including you, can access any encrypted secrets."
+
+          say ""
+          create_file "config/secrets.yml.key", key
+          say ""
+        end
+      end
+
+      def ignore_key_file
+        if File.exist?(".gitignore")
+          unless File.read(".gitignore").include?(key_ignore)
+            say "Ignoring config/secrets.yml.key so it won't end up in Git history:"
+            say ""
+            append_to_file ".gitignore", key_ignore
+            say ""
+          end
+        else
+          say "IMPORTANT: Don't commit config/secrets.yml.key. Add this to your ignore file:"
+          say key_ignore, :on_green
+          say ""
+        end
+      end
+
+      def add_encrypted_secrets_file
+        unless File.exist?("config/secrets.yml.enc")
+          say "Adding config/secrets.yml.enc to store secrets that needs to be encrypted."
+          say ""
+
+          template "config/secrets.yml.enc" do |prefill|
+            say ""
+            say "For now the file contains this but it's been encrypted with the generated key:"
+            say ""
+            say prefill, :on_green
+            say ""
+
+            Secrets.encrypt(prefill)
+          end
+
+          say "You can edit encrypted secrets with `bin/rails secrets:edit`."
+
+          say "Add this to your config/environments/production.rb:"
+          say "config.read_encrypted_secrets = true"
+        end
+      end
+
+      private
+        def key_ignore
+          [ "", "# Ignore encrypted secrets key file.", "config/secrets.yml.key", "" ].join("\n")
+        end
+    end
+  end
+end

railties/lib/rails/generators/rails/encrypted_secrets/templates/config/secrets.yml.enc

@@ -0,0 +1,3 @@
+# See `secrets.yml` for tips on generating suitable keys.
+# production:
+#  external_api_key: 1466aac22e6a869134be3d09b9e89232fc2c2289…

railties/lib/rails/secrets.rb

@@ -0,0 +1,111 @@
+require "yaml"
+
+module Rails
+  # Greatly inspired by Ara T. Howard's magnificent sekrets gem. 😘
+  class Secrets # :nodoc:
+    class MissingKeyError < RuntimeError
+      def initialize
+        super(<<-end_of_message.squish)
+          Missing encryption key to decrypt secrets with.
+          Ask your team for your master key and put it in ENV["RAILS_MASTER_KEY"]
+        end_of_message
+      end
+    end
+
+    @read_encrypted_secrets = false
+    @root = File # Wonky, but ensures `join` uses the current directory.
+
+    class << self
+      attr_writer   :root
+      attr_accessor :read_encrypted_secrets
+
+      def parse(paths, env:)
+        paths.each_with_object(Hash.new) do |path, all_secrets|
+          require "erb"
+
+          secrets = YAML.load(ERB.new(preprocess(path)).result) || {}
+          all_secrets.merge!(secrets["shared"].deep_symbolize_keys) if secrets["shared"]
+          all_secrets.merge!(secrets[env].deep_symbolize_keys) if secrets[env]
+        end
+      end
+
+      def generate_key
+        cipher = new_cipher
+        SecureRandom.hex(cipher.key_len)[0, cipher.key_len]
+      end
+
+      def key
+        ENV["RAILS_MASTER_KEY"] || read_key_file || handle_missing_key
+      end
+
+      def encrypt(text)
+        cipher(:encrypt, text)
+      end
+
+      def decrypt(data)
+        cipher(:decrypt, data)
+      end
+
+      def read
+        decrypt(IO.binread(path))
+      end
+
+      def write(contents)
+        IO.binwrite("#{path}.tmp", encrypt(contents))
+        FileUtils.mv("#{path}.tmp", path)
+      end
+
+      def read_for_editing
+        tmp_path = File.join(Dir.tmpdir, File.basename(path))
+        IO.binwrite(tmp_path, read)
+
+        yield tmp_path
+
+        write(IO.binread(tmp_path))
+      ensure
+        FileUtils.rm(tmp_path) if File.exist?(tmp_path)
+      end
+
+      private
+        def handle_missing_key
+          raise MissingKeyError
+        end
+
+        def read_key_file
+          if File.exist?(key_path)
+            IO.binread(key_path).strip
+          end
+        end
+
+        def key_path
+          @root.join("config", "secrets.yml.key")
+        end
+
+        def path
+          @root.join("config", "secrets.yml.enc").to_s
+        end
+
+        def preprocess(path)
+          if path.end_with?(".enc")
+            if @read_encrypted_secrets
+              decrypt(IO.binread(path))
+            else
+              ""
+            end
+          else
+            IO.read(path)
+          end
+        end
+
+        def new_cipher
+          OpenSSL::Cipher.new("aes-256-cbc")
+        end
+
+        def cipher(mode, data)
+          cipher = new_cipher.public_send(mode)
+          cipher.key = key
+          cipher.update(data) << cipher.final
+        end
+    end
+  end
+end

railties/test/generators/app_generator_test.rb

@@ -335,6 +335,7 @@ class AppGeneratorTest < Rails::Generators::TestCase
     end
     assert_file "config/environments/production.rb" do |content|
       assert_match(/# config\.action_mailer\.raise_delivery_errors = false/, content)
+      assert_match(/^  config\.read_encrypted_secrets = true/, content)
     end
   end
 

railties/test/generators/encrypted_secrets_generator_test.rb

@@ -0,0 +1,42 @@
+require "generators/generators_test_helper"
+require "rails/generators/rails/encrypted_secrets/encrypted_secrets_generator"
+
+class EncryptedSecretsGeneratorTest < Rails::Generators::TestCase
+  include GeneratorsTestHelper
+
+  def setup
+    super
+    cd destination_root
+  end
+
+  def test_generates_key_file_and_encrypted_secrets_file
+    run_generator
+
+    assert_file "config/secrets.yml.key", /[\w\d]+/
+
+    assert File.exist?("config/secrets.yml.enc")
+    assert_no_match(/production:\n#  external_api_key: [\w\d]+/, IO.binread("config/secrets.yml.enc"))
+    assert_match(/production:\n#  external_api_key: [\w\d]+/, Rails::Secrets.read)
+  end
+
+  def test_appends_to_gitignore
+    FileUtils.touch(".gitignore")
+
+    run_generator
+
+    assert_file ".gitignore", /config\/secrets.yml.key/, /(?!config\/secrets.yml.enc)/
+  end
+
+  def test_warns_when_ignore_is_missing
+    assert_match(/Add this to your ignore file/i, run_generator)
+  end
+
+  def test_doesnt_generate_a_new_key_file_if_already_opted_in_to_encrypted_secrets
+    FileUtils.mkdir("config")
+    File.open("config/secrets.yml.enc", "w") { |f| f.puts "already secrety" }
+
+    run_generator
+
+    assert_no_file "config/secrets.yml.key"
+  end
+end

railties/test/isolation/abstract_unit.rb

@@ -22,6 +22,7 @@ require "active_support/core_ext/object/blank"
 require "active_support/testing/isolation"
 require "active_support/core_ext/kernel/reporting"
 require "tmpdir"
+require "rails/secrets"
 
 module TestHelpers
   module Paths

railties/test/secrets_test.rb

@@ -0,0 +1,108 @@
+require "abstract_unit"
+require "isolation/abstract_unit"
+require "rails/generators"
+require "rails/generators/rails/encrypted_secrets/encrypted_secrets_generator"
+require "rails/secrets"
+
+class Rails::SecretsTest < ActiveSupport::TestCase
+  include ActiveSupport::Testing::Isolation
+
+  def setup
+    build_app
+
+    @old_read_encrypted_secrets, Rails::Secrets.read_encrypted_secrets =
+      Rails::Secrets.read_encrypted_secrets, true
+  end
+
+  def teardown
+    Rails::Secrets.read_encrypted_secrets = @old_read_encrypted_secrets
+
+    teardown_app
+  end
+
+  test "setting read to false skips parsing" do
+    Rails::Secrets.read_encrypted_secrets = false
+
+    Dir.chdir(app_path) do
+      assert_equal Hash.new, Rails::Secrets.parse(%w( config/secrets.yml.enc ), env: "production")
+    end
+  end
+
+  test "raises when reading secrets without a key" do
+    run_secrets_generator do
+      FileUtils.rm("config/secrets.yml.key")
+
+      assert_raises Rails::Secrets::MissingKeyError do
+        Rails::Secrets.key
+      end
+    end
+  end
+
+  test "reading with ENV variable" do
+    run_secrets_generator do
+      begin
+        old_key = ENV["RAILS_MASTER_KEY"]
+        ENV["RAILS_MASTER_KEY"] = IO.binread("config/secrets.yml.key").strip
+        FileUtils.rm("config/secrets.yml.key")
+
+        assert_match "production:\n#  external_api_key", Rails::Secrets.read
+      ensure
+        ENV["RAILS_MASTER_KEY"] = old_key
+      end
+    end
+  end
+
+  test "reading from key file" do
+    run_secrets_generator do
+      File.binwrite("config/secrets.yml.key", "How do I know you feel it?")
+
+      assert_equal "How do I know you feel it?", Rails::Secrets.key
+    end
+  end
+
+  test "editing" do
+    run_secrets_generator do
+      decrypted_path = nil
+
+      Rails::Secrets.read_for_editing do |tmp_path|
+        decrypted_path = tmp_path
+
+        assert_match(/production:\n#  external_api_key/, File.read(tmp_path))
+
+        File.write(tmp_path, "Empty streets, empty nights. The Downtown Lights.")
+      end
+
+      assert_not File.exist?(decrypted_path)
+      assert_equal "Empty streets, empty nights. The Downtown Lights.", Rails::Secrets.read
+    end
+  end
+
+  test "merging secrets with encrypted precedence" do
+    run_secrets_generator do
+      File.write("config/secrets.yml", <<-end_of_secrets)
+        test:
+          yeah_yeah: lets-go-walking-down-this-empty-street
+      end_of_secrets
+
+      Rails::Secrets.write(<<-end_of_secrets)
+        test:
+          yeah_yeah: lets-walk-in-the-cool-evening-light
+      end_of_secrets
+
+      Rails.application.config.root = app_path
+      Rails.application.instance_variable_set(:@secrets, nil) # Dance around caching 💃🕺
+      assert_equal "lets-walk-in-the-cool-evening-light", Rails.application.secrets.yeah_yeah
+    end
+  end
+
+  private
+    def run_secrets_generator
+      Dir.chdir(app_path) do
+        capture(:stdout) do
+          Rails::Generators::EncryptedSecretsGenerator.start
+        end
+
+        yield
+      end
+    end
+end