pleroma/lib/pleroma/upload.ex

defmodule Pleroma.Upload do
  alias Ecto.UUID
  alias Pleroma.Web
  def store(%Plug.Upload{} = file) do
    uuid = UUID.generate
    upload_folder = Path.join(upload_path(), uuid)
    File.mkdir_p!(upload_folder)
    result_file = Path.join(upload_folder, file.filename)
    File.cp!(file.path, result_file)

    # fix content type on some image uploads
    content_type = if file.content_type == "application/octet-stream" do
      get_content_type(file.path)
    else
      file.content_type
    end

    %{
      "type" => "Image",
      "url" => [%{
        "type" => "Link",
        "mediaType" => content_type,
        "href" => url_for(Path.join(uuid, :cow_uri.urlencode(file.filename)))
      }],
      "name" => file.filename,
      "uuid" => uuid
    }
  end

  def store(%{"img" => "data:image/" <> image_data}) do
    parsed = Regex.named_captures(~r/(?<filetype>jpeg|png|gif);base64,(?<data>.*)/, image_data)
    data = Base.decode64!(parsed["data"])
    uuid = UUID.generate
    upload_folder = Path.join(upload_path(), uuid)
    File.mkdir_p!(upload_folder)
    filename = Base.encode16(:crypto.hash(:sha256, data)) <> ".#{parsed["filetype"]}"
    result_file = Path.join(upload_folder, filename)

    File.write!(result_file, data)

    content_type = "image/#{parsed["filetype"]}"

    %{
      "type" => "Image",
      "url" => [%{
        "type" => "Link",
        "mediaType" => content_type,
        "href" => url_for(Path.join(uuid, :cow_uri.urlencode(filename)))
      }],
      "name" => filename,
      "uuid" => uuid
    }
  end

  defp upload_path do
    settings = Application.get_env(:pleroma, Pleroma.Upload)
    Keyword.fetch!(settings, :uploads)
  end

  defp url_for(file) do
    "#{Web.base_url()}/media/#{file}"
  end

  def get_content_type(file) do
    # PNG: 89 50 4E 47 0D 0A 1A 0A
    # GIF: 47 49 46 38 37 61
    # GIF: 47 49 46 38 39 61
    # JPEG: FF D8 FF DB
    # JPEG: FF D8 FF E0 ?? ?? 4A 46 49 46 00 01
    # JPEG: FF D8 FF E1 ?? ?? 45 78 69 66 00 00
    match = File.open(file, [:read], fn(f) ->
      case IO.binread(f, 8) do
        <<0x89, 0x50, 0x4e, 0x47, 0x0d, 0x0a, 0x1a, 0x0a>> ->
          "image/png"
        <<0x47, 0x49, 0x46, 0x38, _, 0x61, _, _>> ->
          "image/gif"
        <<0xff, 0xd8, 0xff, _, _, _, _, _>> ->
          "image/jpeg"
        _ ->
          "application/octet-stream"
      end
    end)

    case match do
      {:ok, type} -> type
      _e -> "application/octet-stream"
    end
  end
end