Module: Lockbox::CarrierWaveExtensions

Defined in:
lib/lockbox/carrier_wave_extensions.rb

Instance Method Summary collapse

Instance Method Details

#encrypt(**options) ⇒ Object


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# File 'lib/lockbox/carrier_wave_extensions.rb', line 3

def encrypt(**options)
  class_eval do
    # uses same hook as process (before cache)
    # processing can be disabled, so better to keep separate
    before :cache, :encrypt

    define_singleton_method :lockbox_options do
      options
    end

    def encrypt(file)
      # safety check
      # see CarrierWave::Uploader::Cache#cache!
      raise Lockbox::Error, "Expected files to be equal. Please report an issue." unless file && @file && file == @file

      # processors in CarrierWave move updated file to current_path
      # however, this causes versions to use the processed file
      # we only want to change the file for the current version
      @file = CarrierWave::SanitizedFile.new(lockbox_notify("encrypt_file") { lockbox.encrypt_io(file) })
    end

    # TODO safe to memoize?
    def read
      r = super
      lockbox_notify("decrypt_file") { lockbox.decrypt(r) } if r
    end

    # use size of plaintext since read and content type use plaintext
    def size
      read.bytesize
    end

    def content_type
      if Gem::Version.new(CarrierWave::VERSION) >= Gem::Version.new("2.2.1")
        # based on CarrierWave::SanitizedFile#marcel_magic_content_type
        Marcel::Magic.by_magic(read).try(:type) || "invalid/invalid"
      elsif CarrierWave::VERSION.to_i >= 2
        # based on CarrierWave::SanitizedFile#mime_magic_content_type
        MimeMagic.by_magic(read).try(:type) || "invalid/invalid"
      else
        # uses filename
        super
      end
    end

    # disable processing since already processed
    def rotate_encryption!
      io = Lockbox::IO.new(read)
      io.original_filename = file.filename
      previous_value = enable_processing
      begin
        self.enable_processing = false
        store!(io)
      ensure
        self.enable_processing = previous_value
      end
    end

    private

    define_method :lockbox do
      @lockbox ||= begin
        table = model ? model.class.table_name : "_uploader"
        attribute = lockbox_name

        Utils.build_box(self, options, table, attribute)
      end
    end

    # for mounted uploaders, use mounted name
    # for others, use uploader name
    def lockbox_name
      if mounted_as
        mounted_as.to_s
      else
        uploader = self
        while uploader.parent_version
          uploader = uploader.parent_version
        end
        uploader.class.name.sub(/Uploader\z/, "").underscore
      end
    end

    # Active Support notifications so it's easier
    # to see when files are encrypted and decrypted
    def lockbox_notify(type)
      if defined?(ActiveSupport::Notifications)
        name = lockbox_name

        # get version
        version, _ = parent_version && parent_version.versions.find { |k, v| v == self }
        name = "#{name} #{version} version" if version

        ActiveSupport::Notifications.instrument("#{type}.lockbox", {name: name}) do
          yield
        end
      else
        yield
      end
    end
  end
end