gitlab-org--gitlab-foss/app/models/active_session.rb

# frozen_string_literal: true

class ActiveSession
  include ActiveModel::Model

  SESSION_BATCH_SIZE = 200
  ALLOWED_NUMBER_OF_ACTIVE_SESSIONS = 100

  attr_writer :session_id

  attr_accessor :created_at, :updated_at,
    :ip_address, :browser, :os,
    :device_name, :device_type,
    :is_impersonated

  def current?(session)
    return false if session_id.nil? || session.id.nil?

    session_id == session.id
  end

  def human_device_type
    device_type&.titleize
  end

  def public_id
    encrypted_id = Gitlab::CryptoHelper.aes256_gcm_encrypt(session_id)
    CGI.escape(encrypted_id)
  end

  def self.set(user, request)
    Gitlab::Redis::SharedState.with do |redis|
      session_id = request.session.id
      client = DeviceDetector.new(request.user_agent)
      timestamp = Time.current

      active_user_session = new(
        ip_address: request.ip,
        browser: client.name,
        os: client.os_name,
        device_name: client.device_name,
        device_type: client.device_type,
        created_at: user.current_sign_in_at || timestamp,
        updated_at: timestamp,
        session_id: session_id,
        is_impersonated: request.session[:impersonator_id].present?
      )

      redis.pipelined do
        redis.setex(
          key_name(user.id, session_id),
          Settings.gitlab['session_expire_delay'] * 60,
          Marshal.dump(active_user_session)
        )

        redis.sadd(
          lookup_key_name(user.id),
          session_id
        )
      end
    end
  end

  def self.list(user)
    Gitlab::Redis::SharedState.with do |redis|
      cleaned_up_lookup_entries(redis, user).map do |entry|
        # rubocop:disable Security/MarshalLoad
        Marshal.load(entry)
        # rubocop:enable Security/MarshalLoad
      end
    end
  end

  def self.destroy(user, session_id)
    Gitlab::Redis::SharedState.with do |redis|
      destroy_sessions(redis, user, [session_id])
    end
  end

  def self.destroy_with_public_id(user, public_id)
    session_id = decrypt_public_id(public_id)
    destroy(user, session_id) unless session_id.nil?
  end

  def self.destroy_sessions(redis, user, session_ids)
    key_names = session_ids.map {|session_id| key_name(user.id, session_id) }
    session_names = session_ids.map {|session_id| "#{Gitlab::Redis::SharedState::SESSION_NAMESPACE}:#{session_id}" }

    redis.srem(lookup_key_name(user.id), session_ids)
    redis.del(key_names)
    redis.del(session_names)
  end

  def self.cleanup(user)
    Gitlab::Redis::SharedState.with do |redis|
      clean_up_old_sessions(redis, user)
      cleaned_up_lookup_entries(redis, user)
    end
  end

  def self.key_name(user_id, session_id = '*')
    "#{Gitlab::Redis::SharedState::USER_SESSIONS_NAMESPACE}:#{user_id}:#{session_id}"
  end

  def self.lookup_key_name(user_id)
    "#{Gitlab::Redis::SharedState::USER_SESSIONS_LOOKUP_NAMESPACE}:#{user_id}"
  end

  def self.list_sessions(user)
    sessions_from_ids(session_ids_for_user(user.id))
  end

  def self.session_ids_for_user(user_id)
    Gitlab::Redis::SharedState.with do |redis|
      redis.smembers(lookup_key_name(user_id))
    end
  end

  def self.sessions_from_ids(session_ids)
    return [] if session_ids.empty?

    Gitlab::Redis::SharedState.with do |redis|
      session_keys = session_ids.map { |session_id| "#{Gitlab::Redis::SharedState::SESSION_NAMESPACE}:#{session_id}" }

      session_keys.each_slice(SESSION_BATCH_SIZE).flat_map do |session_keys_batch|
        redis.mget(session_keys_batch).compact.map do |raw_session|
          # rubocop:disable Security/MarshalLoad
          Marshal.load(raw_session)
          # rubocop:enable Security/MarshalLoad
        end
      end
    end
  end

  def self.raw_active_session_entries(redis, session_ids, user_id)
    return [] if session_ids.empty?

    entry_keys = session_ids.map { |session_id| key_name(user_id, session_id) }

    redis.mget(entry_keys)
  end

  def self.active_session_entries(session_ids, user_id, redis)
    return [] if session_ids.empty?

    entry_keys = raw_active_session_entries(redis, session_ids, user_id)

    entry_keys.compact.map do |raw_session|
      Marshal.load(raw_session) # rubocop:disable Security/MarshalLoad
    end
  end

  def self.clean_up_old_sessions(redis, user)
    session_ids = session_ids_for_user(user.id)

    return if session_ids.count <= ALLOWED_NUMBER_OF_ACTIVE_SESSIONS

    # remove sessions if there are more than ALLOWED_NUMBER_OF_ACTIVE_SESSIONS.
    sessions = active_session_entries(session_ids, user.id, redis)
    sessions.sort_by! {|session| session.updated_at }.reverse!
    destroyable_sessions = sessions.drop(ALLOWED_NUMBER_OF_ACTIVE_SESSIONS)
    destroyable_session_ids = destroyable_sessions.map { |session| session.send :session_id } # rubocop:disable GitlabSecurity/PublicSend
    destroy_sessions(redis, user, destroyable_session_ids) if destroyable_session_ids.any?
  end

  def self.cleaned_up_lookup_entries(redis, user)
    session_ids = session_ids_for_user(user.id)
    entries = raw_active_session_entries(redis, session_ids, user.id)

    # remove expired keys.
    # only the single key entries are automatically expired by redis, the
    # lookup entries in the set need to be removed manually.
    session_ids_and_entries = session_ids.zip(entries)
    redis.pipelined do
      session_ids_and_entries.reject { |_session_id, entry| entry }.each do |session_id, _entry|
        redis.srem(lookup_key_name(user.id), session_id)
      end
    end

    entries.compact
  end

  private_class_method def self.decrypt_public_id(public_id)
    decoded_id = CGI.unescape(public_id)
    Gitlab::CryptoHelper.aes256_gcm_decrypt(decoded_id)
  rescue
    nil
  end

  private

  attr_reader :session_id
end