From 40e5d2303ba1edc51beae66cc15263675980106a Mon Sep 17 00:00:00 2001 From: Akihiko Odaki Date: Mon, 26 Mar 2018 21:02:10 +0900 Subject: [PATCH] Validate HTTP response length while receiving (#6891) to_s method of HTTP::Response keeps blocking while it receives the whole content, no matter how it is big. This means it may waste time to receive unacceptably large files. It may also consume memory and disk in the process. This solves the inefficency by checking response length while receiving. --- app/helpers/jsonld_helper.rb | 2 +- app/lib/exceptions.rb | 1 + app/lib/provider_discovery.rb | 2 +- app/lib/request.rb | 31 +++++++++++- app/models/account.rb | 1 - app/models/application_record.rb | 1 + app/models/concerns/account_avatar.rb | 4 +- app/models/concerns/account_header.rb | 4 +- app/models/concerns/remotable.rb | 6 +-- app/models/custom_emoji.rb | 6 ++- app/models/media_attachment.rb | 7 +-- app/models/preview_card.rb | 5 +- app/services/fetch_atom_service.rb | 11 +++-- app/services/fetch_link_card_service.rb | 2 +- app/services/resolve_account_service.rb | 2 +- .../pubsubhubbub/confirmation_worker.rb | 2 +- spec/lib/request_spec.rb | 49 +++++++++++++++++++ spec/models/concerns/remotable_spec.rb | 5 +- 18 files changed, 115 insertions(+), 26 deletions(-) diff --git a/app/helpers/jsonld_helper.rb b/app/helpers/jsonld_helper.rb index 957a2cbc9..dfb8fcb8b 100644 --- a/app/helpers/jsonld_helper.rb +++ b/app/helpers/jsonld_helper.rb @@ -61,7 +61,7 @@ module JsonLdHelper def fetch_resource_without_id_validation(uri) build_request(uri).perform do |response| - response.code == 200 ? body_to_json(response.to_s) : nil + response.code == 200 ? body_to_json(response.body_with_limit) : nil end end diff --git a/app/lib/exceptions.rb b/app/lib/exceptions.rb index 95e3365c2..e88e98eae 100644 --- a/app/lib/exceptions.rb +++ b/app/lib/exceptions.rb @@ -5,6 +5,7 @@ module Mastodon class NotPermittedError < Error; end class ValidationError < Error; end class HostValidationError < ValidationError; end + class LengthValidationError < ValidationError; end class RaceConditionError < Error; end class UnexpectedResponseError < Error diff --git a/app/lib/provider_discovery.rb b/app/lib/provider_discovery.rb index bbd3a2d43..3bec7211b 100644 --- a/app/lib/provider_discovery.rb +++ b/app/lib/provider_discovery.rb @@ -18,7 +18,7 @@ class ProviderDiscovery < OEmbed::ProviderDiscovery else Request.new(:get, url).perform do |res| raise OEmbed::NotFound, url if res.code != 200 || res.mime_type != 'text/html' - Nokogiri::HTML(res.to_s) + Nokogiri::HTML(res.body_with_limit) end end diff --git a/app/lib/request.rb b/app/lib/request.rb index 8a127c65f..dca93a6e9 100644 --- a/app/lib/request.rb +++ b/app/lib/request.rb @@ -40,7 +40,7 @@ class Request end begin - yield response + yield response.extend(ClientLimit) ensure http_client.close end @@ -99,6 +99,33 @@ class Request @http_client ||= HTTP.timeout(:per_operation, timeout).follow(max_hops: 2) end + module ClientLimit + def body_with_limit(limit = 1.megabyte) + raise Mastodon::LengthValidationError if content_length.present? && content_length > limit + + if charset.nil? + encoding = Encoding::BINARY + else + begin + encoding = Encoding.find(charset) + rescue ArgumentError + encoding = Encoding::BINARY + end + end + + contents = String.new(encoding: encoding) + + while (chunk = readpartial) + contents << chunk + chunk.clear + + raise Mastodon::LengthValidationError if contents.bytesize > limit + end + + contents + end + end + class Socket < TCPSocket class << self def open(host, *args) @@ -118,5 +145,5 @@ class Request end end - private_constant :Socket + private_constant :ClientLimit, :Socket end diff --git a/app/models/account.rb b/app/models/account.rb index 9a83d979f..25e7d7436 100644 --- a/app/models/account.rb +++ b/app/models/account.rb @@ -55,7 +55,6 @@ class Account < ApplicationRecord include AccountHeader include AccountInteractions include Attachmentable - include Remotable include Paginable enum protocol: [:ostatus, :activitypub] diff --git a/app/models/application_record.rb b/app/models/application_record.rb index 71fbba5b3..83134d41a 100644 --- a/app/models/application_record.rb +++ b/app/models/application_record.rb @@ -2,4 +2,5 @@ class ApplicationRecord < ActiveRecord::Base self.abstract_class = true + include Remotable end diff --git a/app/models/concerns/account_avatar.rb b/app/models/concerns/account_avatar.rb index 9e34a9461..2d5ebfca3 100644 --- a/app/models/concerns/account_avatar.rb +++ b/app/models/concerns/account_avatar.rb @@ -4,6 +4,7 @@ module AccountAvatar extend ActiveSupport::Concern IMAGE_MIME_TYPES = ['image/jpeg', 'image/png', 'image/gif'].freeze + LIMIT = 2.megabytes class_methods do def avatar_styles(file) @@ -19,7 +20,8 @@ module AccountAvatar # Avatar upload has_attached_file :avatar, styles: ->(f) { avatar_styles(f) }, convert_options: { all: '-strip' }, processors: [:lazy_thumbnail] validates_attachment_content_type :avatar, content_type: IMAGE_MIME_TYPES - validates_attachment_size :avatar, less_than: 2.megabytes + validates_attachment_size :avatar, less_than: LIMIT + remotable_attachment :avatar, LIMIT end def avatar_original_url diff --git a/app/models/concerns/account_header.rb b/app/models/concerns/account_header.rb index 04c576b28..ef40b8126 100644 --- a/app/models/concerns/account_header.rb +++ b/app/models/concerns/account_header.rb @@ -4,6 +4,7 @@ module AccountHeader extend ActiveSupport::Concern IMAGE_MIME_TYPES = ['image/jpeg', 'image/png', 'image/gif'].freeze + LIMIT = 2.megabytes class_methods do def header_styles(file) @@ -19,7 +20,8 @@ module AccountHeader # Header upload has_attached_file :header, styles: ->(f) { header_styles(f) }, convert_options: { all: '-strip' }, processors: [:lazy_thumbnail] validates_attachment_content_type :header, content_type: IMAGE_MIME_TYPES - validates_attachment_size :header, less_than: 2.megabytes + validates_attachment_size :header, less_than: LIMIT + remotable_attachment :header, LIMIT end def header_original_url diff --git a/app/models/concerns/remotable.rb b/app/models/concerns/remotable.rb index 0f18c5d96..3b8c507c3 100644 --- a/app/models/concerns/remotable.rb +++ b/app/models/concerns/remotable.rb @@ -3,8 +3,8 @@ module Remotable extend ActiveSupport::Concern - included do - attachment_definitions.each_key do |attachment_name| + class_methods do + def remotable_attachment(attachment_name, limit) attribute_name = "#{attachment_name}_remote_url".to_sym method_name = "#{attribute_name}=".to_sym alt_method_name = "reset_#{attachment_name}!".to_sym @@ -33,7 +33,7 @@ module Remotable File.extname(filename) end - send("#{attachment_name}=", StringIO.new(response.to_s)) + send("#{attachment_name}=", StringIO.new(response.body_with_limit(limit))) send("#{attachment_name}_file_name=", basename + extname) self[attribute_name] = url if has_attribute?(attribute_name) diff --git a/app/models/custom_emoji.rb b/app/models/custom_emoji.rb index a77b53c98..476178e86 100644 --- a/app/models/custom_emoji.rb +++ b/app/models/custom_emoji.rb @@ -19,6 +19,8 @@ # class CustomEmoji < ApplicationRecord + LIMIT = 50.kilobytes + SHORTCODE_RE_FRAGMENT = '[a-zA-Z0-9_]{2,}' SCAN_RE = /(?<=[^[:alnum:]:]|\n|^) @@ -29,14 +31,14 @@ class CustomEmoji < ApplicationRecord has_attached_file :image, styles: { static: { format: 'png', convert_options: '-coalesce -strip' } } - validates_attachment :image, content_type: { content_type: 'image/png' }, presence: true, size: { in: 0..50.kilobytes } + validates_attachment :image, content_type: { content_type: 'image/png' }, presence: true, size: { less_than: LIMIT } validates :shortcode, uniqueness: { scope: :domain }, format: { with: /\A#{SHORTCODE_RE_FRAGMENT}\z/ }, length: { minimum: 2 } scope :local, -> { where(domain: nil) } scope :remote, -> { where.not(domain: nil) } scope :alphabetic, -> { order(domain: :asc, shortcode: :asc) } - include Remotable + remotable_attachment :image, LIMIT def local? domain.nil? diff --git a/app/models/media_attachment.rb b/app/models/media_attachment.rb index a4d9cd9d1..ac2aa7ed2 100644 --- a/app/models/media_attachment.rb +++ b/app/models/media_attachment.rb @@ -56,6 +56,8 @@ class MediaAttachment < ApplicationRecord }, }.freeze + LIMIT = 8.megabytes + belongs_to :account, inverse_of: :media_attachments, optional: true belongs_to :status, inverse_of: :media_attachments, optional: true @@ -64,10 +66,9 @@ class MediaAttachment < ApplicationRecord processors: ->(f) { file_processors f }, convert_options: { all: '-quality 90 -strip' } - include Remotable - validates_attachment_content_type :file, content_type: IMAGE_MIME_TYPES + VIDEO_MIME_TYPES - validates_attachment_size :file, less_than: 8.megabytes + validates_attachment_size :file, less_than: LIMIT + remotable_attachment :file, LIMIT validates :account, presence: true validates :description, length: { maximum: 420 }, if: :local? diff --git a/app/models/preview_card.rb b/app/models/preview_card.rb index 86eecdfe5..0c82f06ce 100644 --- a/app/models/preview_card.rb +++ b/app/models/preview_card.rb @@ -26,6 +26,7 @@ class PreviewCard < ApplicationRecord IMAGE_MIME_TYPES = ['image/jpeg', 'image/png', 'image/gif'].freeze + LIMIT = 1.megabytes self.inheritance_column = false @@ -36,11 +37,11 @@ class PreviewCard < ApplicationRecord has_attached_file :image, styles: { original: { geometry: '400x400>', file_geometry_parser: FastGeometryParser } }, convert_options: { all: '-quality 80 -strip' } include Attachmentable - include Remotable validates :url, presence: true, uniqueness: true validates_attachment_content_type :image, content_type: IMAGE_MIME_TYPES - validates_attachment_size :image, less_than: 1.megabytes + validates_attachment_size :image, less_than: LIMIT + remotable_attachment :image, LIMIT before_save :extract_dimensions, if: :link? diff --git a/app/services/fetch_atom_service.rb b/app/services/fetch_atom_service.rb index 48ad5dcd3..62dea8298 100644 --- a/app/services/fetch_atom_service.rb +++ b/app/services/fetch_atom_service.rb @@ -38,13 +38,14 @@ class FetchAtomService < BaseService return nil if response.code != 200 if response.mime_type == 'application/atom+xml' - [@url, { prefetched_body: response.to_s }, :ostatus] + [@url, { prefetched_body: response.body_with_limit }, :ostatus] elsif ['application/activity+json', 'application/ld+json; profile="https://www.w3.org/ns/activitystreams"'].include?(response.mime_type) - json = body_to_json(response.to_s) + body = response.body_with_limit + json = body_to_json(body) if supported_context?(json) && json['type'] == 'Person' && json['inbox'].present? - [json['id'], { prefetched_body: response.to_s, id: true }, :activitypub] + [json['id'], { prefetched_body: body, id: true }, :activitypub] elsif supported_context?(json) && json['type'] == 'Note' - [json['id'], { prefetched_body: response.to_s, id: true }, :activitypub] + [json['id'], { prefetched_body: body, id: true }, :activitypub] else @unsupported_activity = true nil @@ -61,7 +62,7 @@ class FetchAtomService < BaseService end def process_html(response) - page = Nokogiri::HTML(response.to_s) + page = Nokogiri::HTML(response.body_with_limit) json_link = page.xpath('//link[@rel="alternate"]').find { |link| ['application/activity+json', 'application/ld+json; profile="https://www.w3.org/ns/activitystreams"'].include?(link['type']) } atom_link = page.xpath('//link[@rel="alternate"]').find { |link| link['type'] == 'application/atom+xml' } diff --git a/app/services/fetch_link_card_service.rb b/app/services/fetch_link_card_service.rb index 26deb5ecc..d5920a417 100644 --- a/app/services/fetch_link_card_service.rb +++ b/app/services/fetch_link_card_service.rb @@ -45,7 +45,7 @@ class FetchLinkCardService < BaseService Request.new(:get, @url).perform do |res| if res.code == 200 && res.mime_type == 'text/html' - @html = res.to_s + @html = res.body_with_limit @html_charset = res.charset else @html = nil diff --git a/app/services/resolve_account_service.rb b/app/services/resolve_account_service.rb index 034821dc0..744ea24f4 100644 --- a/app/services/resolve_account_service.rb +++ b/app/services/resolve_account_service.rb @@ -181,7 +181,7 @@ class ResolveAccountService < BaseService @atom_body = Request.new(:get, atom_url).perform do |response| raise Mastodon::UnexpectedResponseError, response unless response.code == 200 - response.to_s + response.body_with_limit end end diff --git a/app/workers/pubsubhubbub/confirmation_worker.rb b/app/workers/pubsubhubbub/confirmation_worker.rb index cc2d1225b..c0e7b677e 100644 --- a/app/workers/pubsubhubbub/confirmation_worker.rb +++ b/app/workers/pubsubhubbub/confirmation_worker.rb @@ -57,7 +57,7 @@ class Pubsubhubbub::ConfirmationWorker def callback_get_with_params Request.new(:get, subscription.callback_url, params: callback_params).perform do |response| - @callback_response_body = response.body.to_s + @callback_response_body = response.body_with_limit end end diff --git a/spec/lib/request_spec.rb b/spec/lib/request_spec.rb index 4d6b20dd5..939ac006a 100644 --- a/spec/lib/request_spec.rb +++ b/spec/lib/request_spec.rb @@ -1,6 +1,7 @@ # frozen_string_literal: true require 'rails_helper' +require 'securerandom' describe Request do subject { Request.new(:get, 'http://example.com') } @@ -64,6 +65,12 @@ describe Request do expect_any_instance_of(HTTP::Client).to receive(:close) expect { |block| subject.perform &block }.to yield_control end + + it 'returns response which implements body_with_limit' do + subject.perform do |response| + expect(response).to respond_to :body_with_limit + end + end end context 'with private host' do @@ -81,4 +88,46 @@ describe Request do end end end + + describe "response's body_with_limit method" do + it 'rejects body more than 1 megabyte by default' do + stub_request(:any, 'http://example.com').to_return(body: SecureRandom.random_bytes(2.megabytes)) + expect { subject.perform { |response| response.body_with_limit } }.to raise_error Mastodon::LengthValidationError + end + + it 'accepts body less than 1 megabyte by default' do + stub_request(:any, 'http://example.com').to_return(body: SecureRandom.random_bytes(2.kilobytes)) + expect { subject.perform { |response| response.body_with_limit } }.not_to raise_error + end + + it 'rejects body by given size' do + stub_request(:any, 'http://example.com').to_return(body: SecureRandom.random_bytes(2.kilobytes)) + expect { subject.perform { |response| response.body_with_limit(1.kilobyte) } }.to raise_error Mastodon::LengthValidationError + end + + it 'rejects too large chunked body' do + stub_request(:any, 'http://example.com').to_return(body: SecureRandom.random_bytes(2.megabytes), headers: { 'Transfer-Encoding' => 'chunked' }) + expect { subject.perform { |response| response.body_with_limit } }.to raise_error Mastodon::LengthValidationError + end + + it 'rejects too large monolithic body' do + stub_request(:any, 'http://example.com').to_return(body: SecureRandom.random_bytes(2.megabytes), headers: { 'Content-Length' => 2.megabytes }) + expect { subject.perform { |response| response.body_with_limit } }.to raise_error Mastodon::LengthValidationError + end + + it 'uses binary encoding if Content-Type does not tell encoding' do + stub_request(:any, 'http://example.com').to_return(body: '', headers: { 'Content-Type' => 'text/html' }) + expect(subject.perform { |response| response.body_with_limit.encoding }).to eq Encoding::BINARY + end + + it 'uses binary encoding if Content-Type tells unknown encoding' do + stub_request(:any, 'http://example.com').to_return(body: '', headers: { 'Content-Type' => 'text/html; charset=unknown' }) + expect(subject.perform { |response| response.body_with_limit.encoding }).to eq Encoding::BINARY + end + + it 'uses encoding specified by Content-Type' do + stub_request(:any, 'http://example.com').to_return(body: '', headers: { 'Content-Type' => 'text/html; charset=UTF-8' }) + expect(subject.perform { |response| response.body_with_limit.encoding }).to eq Encoding::UTF_8 + end + end end diff --git a/spec/models/concerns/remotable_spec.rb b/spec/models/concerns/remotable_spec.rb index 0b2dad23f..b39233739 100644 --- a/spec/models/concerns/remotable_spec.rb +++ b/spec/models/concerns/remotable_spec.rb @@ -29,7 +29,10 @@ RSpec.describe Remotable do context 'Remotable module is included' do before do - class Foo; include Remotable; end + class Foo + include Remotable + remotable_attachment :hoge, 1.kilobyte + end end let(:attribute_name) { "#{hoge}_remote_url".to_sym }