Sign out the account's other sessions when its password changes

Changing the password is how someone shuts out whoever else is signed
in to their account, but every session opened with the old password
stayed valid. Now the others end and their live connections close, as
on sign-out. The session the password was changed from stays signed in.

Changing the password outside a request, as from a console, ends every
session.

app/controllers/users/profiles_controller.rb

@@ -8,6 +8,8 @@ class Users::ProfilesController < ApplicationController
 
   def update
     @user.update user_params
+    disconnect_remote_connections if @user.saved_change_to_password_digest?
+
     redirect_to user_profile_url, notice: update_notice
   end
 

app/models/user.rb

@@ -20,6 +20,7 @@ class User < ApplicationRecord
   has_secure_password validations: false
 
   after_create_commit :grant_membership_to_open_rooms
+  after_update :sign_out_other_sessions, if: :saved_change_to_password_digest?
 
   scope :ordered, -> { order("LOWER(name)") }
   scope :filtered_by, ->(query) { where("name like ?", "%#{query}%") }
@@ -50,6 +51,12 @@ class User < ApplicationRecord
   end
 
   private
+    # A new password is how someone shuts out whoever else got into their account, so it ends the sessions opened
+    # with the old one. The session it was changed from, if any, stays.
+    def sign_out_other_sessions
+      sessions.excluding(Current.session).delete_all
+    end
+
     # One statement, which SQLite runs under the write lock, so no room is closed between reading the open ones and
     # inserting. A room that Room#destroy_later closes is either closed before, and skipped, or after, and takes this
     # membership away with the others. A room that granted itself to every user when it was created is skipped too,

test/controllers/cached_responses_test.rb

@@ -136,6 +136,29 @@ class CachedResponsesTest < ActionDispatch::IntegrationTest
     assert_redirected_to new_session_url
   end
 
+  test "a session signed out by a password change isn't served from a cached snapshot or page" do
+    other_device = open_session { |session| session.host! "once.campfire.test" }
+    other_device.post session_url, params: { email_address: users(:david).email_address, password: "secret123456" }
+    other_device.get user_sidebar_url(:me)
+    other_device.assert_response :success
+
+    Session.expects(:find_by).never
+    ResponseCache.instance.expects(:write).never
+    other_device.get user_sidebar_url(:me)
+    other_device.assert_response :success
+    Session.unstub(:find_by)
+    ResponseCache.instance.unstub(:write)
+
+    put user_profile_url, params: { user: { password: "a new secret123456" } },
+      headers: { "Sec-Fetch-Site" => "same-origin", "Origin" => "http://once.campfire.test" }
+    assert_redirected_to user_profile_url
+
+    other_device.get user_sidebar_url(:me)
+    other_device.assert_redirected_to new_session_url
+    get user_sidebar_url(:me)
+    assert_response :success
+  end
+
   test "conditional requests keep native validators" do
     get room_messages_url(@room)
     etag = response.headers["ETag"]

test/controllers/users/profiles_controller_test.rb

@@ -27,6 +27,52 @@ class Users::ProfilesControllerTest < ActionDispatch::IntegrationTest
     assert_equal "david@37signals.com", users(:david).email_address
   end
 
+  test "changing the password signs out the account's other sessions but not this one" do
+    other_device = open_session
+    other_device.post session_url, params: { email_address: users(:david).email_address, password: "secret123456" }
+    other_device.get user_profile_url
+    other_device.assert_response :success
+
+    put user_profile_url, params: { user: { password: "a new secret123456" } }
+    assert_redirected_to user_profile_url
+
+    other_device.get user_profile_url
+    other_device.assert_redirected_to new_session_url
+    get user_profile_url
+    assert_response :success
+    assert_equal 1, users(:david).sessions.count
+  end
+
+  test "changing the password closes the account's live connections" do
+    remote_connections = mock
+    remote_connections.expects(:disconnect).with(reconnect: true)
+    ActionCable.server.stubs(:remote_connections).returns(mock.tap { |m| m.expects(:where).with(current_user: users(:david)).returns(remote_connections) })
+
+    put user_profile_url, params: { user: { password: "a new secret123456" } }
+
+    assert_redirected_to user_profile_url
+  end
+
+  test "changing the password still signs out other sessions when the realtime service is unreachable" do
+    other_session = users(:david).sessions.first
+    ActionCable.server.stubs(:remote_connections).raises(RuntimeError.new("cable down"))
+
+    put user_profile_url, params: { user: { password: "a new secret123456" } }
+
+    assert_redirected_to user_profile_url
+    assert_not Session.exists?(other_session.id)
+  end
+
+  test "updating the profile without a new password leaves other sessions signed in" do
+    ActionCable.server.expects(:remote_connections).never
+
+    assert_no_difference -> { users(:david).sessions.count } do
+      put user_profile_url, params: { user: { name: "David", password: "" } }
+    end
+
+    assert_redirected_to user_profile_url
+  end
+
   test "updates are limited to the current user" do
     put user_profile_url(users(:jason)), params: { user: { name: "John Doe" } }
 

test/models/user_test.rb

@@ -42,6 +42,28 @@ class UserTest < ActiveSupport::TestCase
     end
   end
 
+  test "changing the password outside a request signs out every session" do
+    users(:david).sessions.start!(user_agent: "Other device", ip_address: "127.0.0.1")
+
+    assert_changes -> { users(:david).sessions.count }, to: 0 do
+      users(:david).update!(password: "a new secret123456")
+    end
+  end
+
+  test "changing the password keeps the session it was changed from" do
+    Current.session = users(:david).sessions.start!(user_agent: "This device", ip_address: "127.0.0.1")
+
+    users(:david).update!(password: "a new secret123456")
+
+    assert_equal [ Current.session ], users(:david).sessions.reload
+  end
+
+  test "changing other details keeps every session" do
+    assert_no_changes -> { users(:david).sessions.count } do
+      users(:david).update!(name: "Dave", email_address: "dave@37signals.com")
+    end
+  end
+
   private
     def create_new_user
       User.create!(name: "User", email_address: "user@example.com", password: "secret123456")