Add E2EE API (#13820)

Gemfile

@@ -50,6 +50,7 @@ gem 'omniauth', '~> 1.9'
 
 gem 'discard', '~> 1.2'
 gem 'doorkeeper', '~> 5.4'
+gem 'ed25519', '~> 1.2'
 gem 'fast_blank', '~> 1.0'
 gem 'fastimage'
 gem 'goldfinger', '~> 2.1'

Gemfile.lock

@@ -201,6 +201,7 @@ GEM
       dotenv (= 2.7.5)
       railties (>= 3.2, < 6.1)
     e2mmap (0.1.0)
+    ed25519 (1.2.4)
     elasticsearch (7.7.0)
       elasticsearch-api (= 7.7.0)
       elasticsearch-transport (= 7.7.0)
@@ -701,6 +702,7 @@ DEPENDENCIES
   doorkeeper (~> 5.4)
   dotenv-rails (~> 2.7)
   e2mmap (~> 0.1.0)
+  ed25519 (~> 1.2)
   fabrication (~> 2.21)
   faker (~> 2.12)
   fast_blank (~> 1.0)

app/controllers/activitypub/claims_controller.rb

+# frozen_string_literal: true
+
+class ActivityPub::ClaimsController < ActivityPub::BaseController
+  include SignatureVerification
+  include AccountOwnedConcern
+
+  skip_before_action :authenticate_user!
+
+  before_action :require_signature!
+  before_action :set_claim_result
+
+  def create
+    render json: @claim_result, serializer: ActivityPub::OneTimeKeySerializer
+  end
+
+  private
+
+  def set_claim_result
+    @claim_result = ::Keys::ClaimService.new.call(@account.id, params[:id])
+  end
+end

app/controllers/activitypub/collections_controller.rb

@@ -5,8 +5,9 @@ class ActivityPub::CollectionsController < ActivityPub::BaseController
   include AccountOwnedConcern
 
   before_action :require_signature!, if: :authorized_fetch_mode?
+  before_action :set_items
   before_action :set_size
-  before_action :set_statuses
+  before_action :set_type
   before_action :set_cache_headers
 
   def show
@@ -16,40 +17,53 @@ class ActivityPub::CollectionsController < ActivityPub::BaseController
 
   private
 
-  def set_statuses
-    @statuses = scope_for_collection
-    @statuses = cache_collection(@statuses, Status)
+  def set_items
+    case params[:id]
+    when 'featured'
+      @items = begin
+        # Because in public fetch mode we cache the response, there would be no
+        # benefit from performing the check below, since a blocked account or domain
+        # would likely be served the cache from the reverse proxy anyway
+
+        if authorized_fetch_mode? && !signed_request_account.nil? && (@account.blocking?(signed_request_account) || (!signed_request_account.domain.nil? && @account.domain_blocking?(signed_request_account.domain)))
+          []
+        else
+          cache_collection(@account.pinned_statuses, Status)
+        end
+      end
+    when 'devices'
+      @items = @account.devices
+    else
+      not_found
+    end
   end
 
   def set_size
     case params[:id]
-    when 'featured'
-      @size = @account.pinned_statuses.count
+    when 'featured', 'devices'
+      @size = @items.size
     else
       not_found
     end
   end
 
-  def scope_for_collection
+  def set_type
     case params[:id]
     when 'featured'
-      # Because in public fetch mode we cache the response, there would be no
-      # benefit from performing the check below, since a blocked account or domain
-      # would likely be served the cache from the reverse proxy anyway
-      if authorized_fetch_mode? && !signed_request_account.nil? && (@account.blocking?(signed_request_account) || (!signed_request_account.domain.nil? && @account.domain_blocking?(signed_request_account.domain)))
-        Status.none
-      else
-        @account.pinned_statuses
-      end
+      @type = :ordered
+    when 'devices'
+      @type = :unordered
+    else
+      not_found
     end
   end
 
   def collection_presenter
     ActivityPub::CollectionPresenter.new(
       id: account_collection_url(@account, params[:id]),
-      type: :ordered,
+      type: @type,
       size: @size,
-      items: @statuses
+      items: @items
     )
   end
 end

app/controllers/api/v1/crypto/deliveries_controller.rb

+# frozen_string_literal: true
+
+class Api::V1::Crypto::DeliveriesController < Api::BaseController
+  before_action -> { doorkeeper_authorize! :crypto }
+  before_action :require_user!
+  before_action :set_current_device
+
+  def create
+    devices.each do |device_params|
+      DeliverToDeviceService.new.call(current_account, @current_device, device_params)
+    end
+
+    render_empty
+  end
+
+  private
+
+  def set_current_device
+    @current_device = Device.find_by!(access_token: doorkeeper_token)
+  end
+
+  def resource_params
+    params.require(:device)
+    params.permit(device: [:account_id, :device_id, :type, :body, :hmac])
+  end
+
+  def devices
+    Array(resource_params[:device])
+  end
+end

app/controllers/api/v1/crypto/encrypted_messages_controller.rb

+# frozen_string_literal: true
+
+class Api::V1::Crypto::EncryptedMessagesController < Api::BaseController
+  LIMIT = 80
+
+  before_action -> { doorkeeper_authorize! :crypto }
+  before_action :require_user!
+  before_action :set_current_device
+
+  before_action :set_encrypted_messages,    only: :index
+  after_action  :insert_pagination_headers, only: :index
+
+  def index
+    render json: @encrypted_messages, each_serializer: REST::EncryptedMessageSerializer
+  end
+
+  def clear
+    @current_device.encrypted_messages.up_to(params[:up_to_id]).delete_all
+    render_empty
+  end
+
+  private
+
+  def set_current_device
+    @current_device = Device.find_by!(access_token: doorkeeper_token)
+  end
+
+  def set_encrypted_messages
+    @encrypted_messages = @current_device.encrypted_messages.paginate_by_id(limit_param(LIMIT), params_slice(:max_id, :since_id, :min_id))
+  end
+
+  def insert_pagination_headers
+    set_pagination_headers(next_path, prev_path)
+  end
+
+  def next_path
+    api_v1_encrypted_messages_url pagination_params(max_id: pagination_max_id) if records_continue?
+  end
+
+  def prev_path
+    api_v1_encrypted_messages_url pagination_params(min_id: pagination_since_id) unless @encrypted_messages.empty?
+  end
+
+  def pagination_max_id
+    @encrypted_messages.last.id
+  end
+
+  def pagination_since_id
+    @encrypted_messages.first.id
+  end
+
+  def records_continue?
+    @encrypted_messages.size == limit_param(LIMIT)
+  end
+
+  def pagination_params(core_params)
+    params.slice(:limit).permit(:limit).merge(core_params)
+  end
+end

app/controllers/api/v1/crypto/keys/claims_controller.rb

+# frozen_string_literal: true
+
+class Api::V1::Crypto::Keys::ClaimsController < Api::BaseController
+  before_action -> { doorkeeper_authorize! :crypto }
+  before_action :require_user!
+  before_action :set_claim_results
+
+  def create
+    render json: @claim_results, each_serializer: REST::Keys::ClaimResultSerializer
+  end
+
+  private
+
+  def set_claim_results
+    @claim_results = devices.map { |device_params| ::Keys::ClaimService.new.call(current_account, device_params[:account_id], device_params[:device_id]) }.compact
+  end
+
+  def resource_params
+    params.permit(device: [:account_id, :device_id])
+  end
+
+  def devices
+    Array(resource_params[:device])
+  end
+end

app/controllers/api/v1/crypto/keys/counts_controller.rb

+# frozen_string_literal: true
+
+class Api::V1::Crypto::Keys::CountsController < Api::BaseController
+  before_action -> { doorkeeper_authorize! :crypto }
+  before_action :require_user!
+  before_action :set_current_device
+
+  def show
+    render json: { one_time_keys: @current_device.one_time_keys.count }
+  end
+
+  private
+
+  def set_current_device
+    @current_device = Device.find_by!(access_token: doorkeeper_token)
+  end
+end

app/controllers/api/v1/crypto/keys/queries_controller.rb

+# frozen_string_literal: true
+
+class Api::V1::Crypto::Keys::QueriesController < Api::BaseController
+  before_action -> { doorkeeper_authorize! :crypto }
+  before_action :require_user!
+  before_action :set_accounts
+  before_action :set_query_results
+
+  def create
+    render json: @query_results, each_serializer: REST::Keys::QueryResultSerializer
+  end
+
+  private
+
+  def set_accounts
+    @accounts = Account.where(id: account_ids).includes(:devices)
+  end
+
+  def set_query_results
+    @query_results = @accounts.map { |account| ::Keys::QueryService.new.call(account) }.compact
+  end
+
+  def account_ids
+    Array(params[:id]).map(&:to_i)
+  end
+end

app/controllers/api/v1/crypto/keys/uploads_controller.rb

+# frozen_string_literal: true
+
+class Api::V1::Crypto::Keys::UploadsController < Api::BaseController
+  before_action -> { doorkeeper_authorize! :crypto }
+  before_action :require_user!
+
+  def create
+    device = Device.find_or_initialize_by(access_token: doorkeeper_token)
+
+    device.transaction do
+      device.account = current_account
+      device.update!(resource_params[:device])
+
+      if resource_params[:one_time_keys].present? && resource_params[:one_time_keys].is_a?(Enumerable)
+        resource_params[:one_time_keys].each do |one_time_key_params|
+          device.one_time_keys.create!(one_time_key_params)
+        end
+      end
+    end
+
+    render json: device, serializer: REST::Keys::DeviceSerializer
+  end
+
+  private
+
+  def resource_params
+    params.permit(device: [:device_id, :name, :fingerprint_key, :identity_key], one_time_keys: [:key_id, :key, :signature])
+  end
+end

app/controllers/statuses_controller.rb

@@ -42,7 +42,7 @@ class StatusesController < ApplicationController
 
   def activity
     expires_in 3.minutes, public: @status.distributable? && public_fetch_mode?
-    render_with_cache json: @status, content_type: 'application/activity+json', serializer: ActivityPub::ActivitySerializer, adapter: ActivityPub::Adapter
+    render_with_cache json: ActivityPub::ActivityPresenter.from_status(@status), content_type: 'application/activity+json', serializer: ActivityPub::ActivitySerializer, adapter: ActivityPub::Adapter
   end
 
   def embed

app/lib/activitypub/activity/create.rb

@@ -2,6 +2,45 @@
 
 class ActivityPub::Activity::Create < ActivityPub::Activity
   def perform
+    case @object['type']
+    when 'EncryptedMessage'
+      create_encrypted_message
+    else
+      create_status
+    end
+  end
+
+  private
+
+  def create_encrypted_message
+    return reject_payload! if invalid_origin?(@object['id']) || @options[:delivered_to_account_id].blank?
+
+    target_account = Account.find(@options[:delivered_to_account_id])
+    target_device  = target_account.devices.find_by(device_id: @object.dig('to', 'deviceId'))
+
+    return if target_device.nil?
+
+    target_device.encrypted_messages.create!(
+      from_account: @account,
+      from_device_id: @object.dig('attributedTo', 'deviceId'),
+      type: @object['messageType'],
+      body: @object['cipherText'],
+      digest: @object.dig('digest', 'digestValue'),
+      message_franking: message_franking.to_token
+    )
+  end
+
+  def message_franking
+    MessageFranking.new(
+      hmac: @object.dig('digest', 'digestValue'),
+      original_franking: @object['messageFranking'],
+      source_account_id: @account.id,
+      target_account_id: @options[:delivered_to_account_id],
+      timestamp: Time.now.utc
+    )
+  end
+
+  def create_status
     return reject_payload! if unsupported_object_type? || invalid_origin?(@object['id']) || Tombstone.exists?(uri: @object['id']) || !related_to_local_activity?
 
     RedisLock.acquire(lock_options) do |lock|
@@ -23,8 +62,6 @@ class ActivityPub::Activity::Create < ActivityPub::Activity
     @status
   end
 
-  private
-
   def audience_to
     @object['to'] || @json['to']
   end
@@ -262,6 +299,7 @@ class ActivityPub::Activity::Create < ActivityPub::Activity
   def poll_vote!
     poll = replied_to_status.preloadable_poll
     already_voted = true
+
     RedisLock.acquire(poll_lock_options) do |lock|
       if lock.acquired?
         already_voted = poll.votes.where(account: @account).exists?
@@ -270,20 +308,24 @@ class ActivityPub::Activity::Create < ActivityPub::Activity
         raise Mastodon::RaceConditionError
       end
     end
+
     increment_voters_count! unless already_voted
     ActivityPub::DistributePollUpdateWorker.perform_in(3.minutes, replied_to_status.id) unless replied_to_status.preloadable_poll.hide_totals?
   end
 
   def resolve_thread(status)
     return unless status.reply? && status.thread.nil? && Request.valid_url?(in_reply_to_uri)
+
     ThreadResolveWorker.perform_async(status.id, in_reply_to_uri)
   end
 
   def fetch_replies(status)
     collection = @object['replies']
     return if collection.nil?
+
     replies = ActivityPub::FetchRepliesService.new.call(status, collection, false)
     return unless replies.nil?
+
     uri = value_or_id(collection)
     ActivityPub::FetchRepliesWorker.perform_async(status.id, uri) unless uri.nil?
   end
@@ -291,6 +333,7 @@ class ActivityPub::Activity::Create < ActivityPub::Activity
   def conversation_from_uri(uri)
     return nil if uri.nil?
     return Conversation.find_by(id: OStatus::TagManager.instance.unique_tag_to_local_id(uri, 'Conversation')) if OStatus::TagManager.instance.local_id?(uri)
+
     begin
       Conversation.find_or_create_by!(uri: uri)
     rescue ActiveRecord::RecordInvalid, ActiveRecord::RecordNotUnique
@@ -404,6 +447,7 @@ class ActivityPub::Activity::Create < ActivityPub::Activity
 
   def skip_download?
     return @skip_download if defined?(@skip_download)
+
     @skip_download ||= DomainBlock.reject_media?(@account.domain)
   end
 
@@ -436,11 +480,13 @@ class ActivityPub::Activity::Create < ActivityPub::Activity
 
   def forward_for_reply
     return unless @json['signature'].present? && reply_to_local?
+
     ActivityPub::RawDistributionWorker.perform_async(Oj.dump(@json), replied_to_status.account_id, [@account.preferred_inbox_url])
   end
 
   def increment_voters_count!
     poll = replied_to_status.preloadable_poll
+
     unless poll.voters_count.nil?
       poll.voters_count = poll.voters_count + 1
       poll.save

app/lib/activitypub/adapter.rb

@@ -22,6 +22,7 @@ class ActivityPub::Adapter < ActiveModelSerializers::Adapter::Base
     blurhash: { 'toot' => 'http://joinmastodon.org/ns#', 'blurhash' => 'toot:blurhash' },
     discoverable: { 'toot' => 'http://joinmastodon.org/ns#', 'discoverable' => 'toot:discoverable' },
     voters_count: { 'toot' => 'http://joinmastodon.org/ns#', 'votersCount' => 'toot:votersCount' },
+    olm: { 'toot' => 'http://joinmastodon.org/ns#', 'Device' => 'toot:Device', 'Ed25519Signature' => 'toot:Ed25519Signature', 'Ed25519Key' => 'toot:Ed25519Key', 'Curve25519Key' => 'toot:Curve25519Key', 'EncryptedMessage' => 'toot:EncryptedMessage', 'publicKeyBase64' => 'toot:publicKeyBase64', 'deviceId' => 'toot:deviceId', 'claim' => { '@type' => '@id', '@id' => 'toot:claim' }, 'fingerprintKey' => { '@type' => '@id', '@id' => 'toot:fingerprintKey' }, 'identityKey' => { '@type' => '@id', '@id' => 'toot:identityKey' }, 'devices' => { '@type' => '@id', '@id' => 'toot:devices' }, 'messageFranking' => 'toot:messageFranking', 'messageType' => 'toot:messageType', 'cipherText' => 'toot:cipherText' },
   }.freeze
 
   def self.default_key_transform

app/lib/inline_renderer.rb

@@ -19,6 +19,8 @@ class InlineRenderer
       serializer = REST::AnnouncementSerializer
     when :reaction
       serializer = REST::ReactionSerializer
+    when :encrypted_message
+      serializer = REST::EncryptedMessageSerializer
     else
       return
     end

app/models/account.rb

@@ -49,6 +49,7 @@
 #  hide_collections              :boolean
 #  avatar_storage_schema_version :integer
 #  header_storage_schema_version :integer
+#  devices_url                   :string
 #
 
 class Account < ApplicationRecord

app/models/concerns/account_associations.rb

@@ -9,6 +9,7 @@ module AccountAssociations
 
     # Identity proofs
     has_many :identity_proofs, class_name: 'AccountIdentityProof', dependent: :destroy, inverse_of: :account
+    has_many :devices, dependent: :destroy, inverse_of: :account
 
     # Timelines
     has_many :statuses, inverse_of: :account, dependent: :destroy

app/models/device.rb

+# frozen_string_literal: true
+# == Schema Information
+#
+# Table name: devices
+#
+#  id              :bigint(8)        not null, primary key
+#  access_token_id :bigint(8)
+#  account_id      :bigint(8)
+#  device_id       :string           default(""), not null
+#  name            :string           default(""), not null
+#  fingerprint_key :text             default(""), not null
+#  identity_key    :text             default(""), not null
+#  created_at      :datetime         not null
+#  updated_at      :datetime         not null
+#
+
+class Device < ApplicationRecord
+  belongs_to :access_token, class_name: 'Doorkeeper::AccessToken'
+  belongs_to :account
+
+  has_many :one_time_keys, dependent: :destroy, inverse_of: :device
+  has_many :encrypted_messages, dependent: :destroy, inverse_of: :device
+
+  validates :name, :fingerprint_key, :identity_key, presence: true
+  validates :fingerprint_key, :identity_key, ed25519_key: true
+
+  before_save :invalidate_associations, if: -> { device_id_changed? || fingerprint_key_changed? || identity_key_changed? }
+
+  private
+
+  def invalidate_associations
+    one_time_keys.destroy_all
+    encrypted_messages.destroy_all
+  end
+end

app/models/encrypted_message.rb

+# frozen_string_literal: true
+# == Schema Information
+#
+# Table name: encrypted_messages
+#
+#  id               :bigint(8)        not null, primary key
+#  device_id        :bigint(8)
+#  from_account_id  :bigint(8)
+#  from_device_id   :string           default(""), not null
+#  type             :integer          default(0), not null
+#  body             :text             default(""), not null
+#  digest           :text             default(""), not null
+#  message_franking :text             default(""), not null
+#  created_at       :datetime         not null
+#  updated_at       :datetime         not null
+#
+
+class EncryptedMessage < ApplicationRecord
+  self.inheritance_column = nil
+
+  include Paginable
+
+  scope :up_to, ->(id) { where(arel_table[:id].lteq(id)) }
+
+  belongs_to :device
+  belongs_to :from_account, class_name: 'Account'
+
+  around_create Mastodon::Snowflake::Callbacks
+
+  after_commit :push_to_streaming_api
+
+  private
+
+  def push_to_streaming_api
+    Rails.logger.info(streaming_channel)
+    Rails.logger.info(subscribed_to_timeline?)
+
+    return if destroyed? || !subscribed_to_timeline?
+
+    PushEncryptedMessageWorker.perform_async(id)
+  end
+
+  def subscribed_to_timeline?
+    Redis.current.exists("subscribed:#{streaming_channel}")
+  end
+
+  def streaming_channel
+    "timeline:#{device.account_id}:#{device.device_id}"
+  end
+end

app/models/message_franking.rb

+# frozen_string_literal: true
+
+class MessageFranking
+  attr_reader :hmac, :source_account_id, :target_account_id,
+              :timestamp, :original_franking
+
+  def initialize(attributes = {})
+    @hmac              = attributes[:hmac]
+    @source_account_id = attributes[:source_account_id]
+    @target_account_id = attributes[:target_account_id]
+    @timestamp         = attributes[:timestamp]
+    @original_franking = attributes[:original_franking]
+  end
+
+  def to_token
+    crypt = ActiveSupport::MessageEncryptor.new(SystemKey.current_key, serializer: Oj)
+    crypt.encrypt_and_sign(self)
+  end
+end

app/models/one_time_key.rb

+# frozen_string_literal: true
+# == Schema Information
+#
+# Table name: one_time_keys
+#
+#  id         :bigint(8)        not null, primary key
+#  device_id  :bigint(8)
+#  key_id     :string           default(""), not null
+#  key        :text             default(""), not null
+#  signature  :text             default(""), not null
+#  created_at :datetime         not null
+#  updated_at :datetime         not null
+#
+
+class OneTimeKey < ApplicationRecord
+  belongs_to :device
+
+  validates :key_id, :key, :signature, presence: true
+  validates :key, ed25519_key: true
+  validates :signature, ed25519_signature: { message: :key, verify_key: ->(one_time_key) { one_time_key.device.fingerprint_key } }
+end