gab-social/app/lib/request.rb

209 lines
5.3 KiB
Ruby

# frozen_string_literal: true
require 'ipaddr'
require 'socket'
require 'resolv'
# Monkey-patch the HTTP.rb timeout class to avoid using a timeout block
# around the Socket#open method, since we use our own timeout blocks inside
# that method
class HTTP::Timeout::PerOperation
def connect(socket_class, host, port, nodelay = false)
@socket = socket_class.open(host, port)
@socket.setsockopt(Socket::IPPROTO_TCP, Socket::TCP_NODELAY, 1) if nodelay
end
end
class Request
REQUEST_TARGET = '(request-target)'
include RoutingHelper
def initialize(verb, url, **options)
raise ArgumentError if url.blank?
@verb = verb
@url = Addressable::URI.parse(url).normalize
@options = options.merge(use_proxy? ? Rails.configuration.x.http_client_proxy : { socket_class: Socket })
@headers = {}
raise GabSocial::HostValidationError, 'Instance does not support hidden service connections' if block_hidden_service?
set_common_headers!
set_digest! if options.key?(:body)
end
def on_behalf_of(account, key_id_format = :acct, sign_with: nil)
raise ArgumentError unless account.local?
@account = account
@keypair = sign_with.present? ? OpenSSL::PKey::RSA.new(sign_with) : @account.keypair
@key_id_format = key_id_format
self
end
def add_headers(new_headers)
@headers.merge!(new_headers)
self
end
def perform
begin
response = http_client.headers(headers).public_send(@verb, @url.to_s, @options)
rescue => e
raise e.class, "#{e.message} on #{@url}", e.backtrace[0]
end
begin
yield response.extend(ClientLimit) if block_given?
ensure
http_client.close
end
end
def headers
(@account ? @headers.merge('Signature' => signature) : @headers).without(REQUEST_TARGET)
end
class << self
def valid_url?(url)
begin
parsed_url = Addressable::URI.parse(url)
rescue Addressable::URI::InvalidURIError
return false
end
%w(http https).include?(parsed_url.scheme) && parsed_url.host.present?
end
end
private
def set_common_headers!
@headers[REQUEST_TARGET] = "#{@verb} #{@url.path}"
@headers['User-Agent'] = GabSocial::Version.user_agent
@headers['Host'] = @url.host
@headers['Date'] = Time.now.utc.httpdate
@headers['Accept-Encoding'] = 'gzip' if @verb != :head
end
def set_digest!
@headers['Digest'] = "SHA-256=#{Digest::SHA256.base64digest(@options[:body])}"
end
def signature
algorithm = 'rsa-sha256'
signature = Base64.strict_encode64(@keypair.sign(OpenSSL::Digest::SHA256.new, signed_string))
"keyId=\"#{key_id}\",algorithm=\"#{algorithm}\",headers=\"#{signed_headers.keys.join(' ').downcase}\",signature=\"#{signature}\""
end
def signed_string
signed_headers.map { |key, value| "#{key.downcase}: #{value}" }.join("\n")
end
def signed_headers
@headers.without('User-Agent', 'Accept-Encoding')
end
def key_id
case @key_id_format
when :acct
@account.to_webfinger_s
when :uri
[ActivityPub::TagManager.instance.uri_for(@account), '#main-key'].join
end
end
def timeout
# We enforce a 1s timeout on DNS resolving, 10s timeout on socket opening
# and 5s timeout on the TLS handshake, meaning the worst case should take
# about 16s in total
{ connect: 5, read: 10, write: 10 }
end
def http_client
@http_client ||= HTTP.use(:auto_inflate).timeout(:per_operation, timeout).follow(max_hops: 2)
end
def use_proxy?
Rails.configuration.x.http_client_proxy.present?
end
def block_hidden_service?
!Rails.configuration.x.access_to_hidden_service && /\.(onion|i2p)$/.match(@url.host)
end
module ClientLimit
def body_with_limit(limit = 1.megabyte)
raise GabSocial::LengthValidationError if content_length.present? && content_length > limit
if charset.nil?
encoding = Encoding::BINARY
else
begin
encoding = Encoding.find(charset)
rescue ArgumentError
encoding = Encoding::BINARY
end
end
contents = String.new(encoding: encoding)
while (chunk = readpartial)
contents << chunk
chunk.clear
raise GabSocial::LengthValidationError if contents.bytesize > limit
end
contents
end
end
class Socket < TCPSocket
class << self
def open(host, *args)
return super(host, *args) if thru_hidden_service?(host)
outer_e = nil
Resolv::DNS.open do |dns|
dns.timeouts = 5
addresses = dns.getaddresses(host).take(2)
time_slot = 10.0 / addresses.size
addresses.each do |address|
begin
raise GabSocial::HostValidationError if PrivateAddressCheck.private_address?(IPAddr.new(address.to_s))
::Timeout.timeout(time_slot, HTTP::TimeoutError) do
return super(address.to_s, *args)
end
rescue => e
outer_e = e
end
end
end
if outer_e
raise outer_e
else
raise SocketError, "No address for #{host}"
end
end
alias new open
def thru_hidden_service?(host)
Rails.configuration.x.access_to_hidden_service && /\.(onion|i2p)$/.match(host)
end
end
end
private_constant :ClientLimit, :Socket
end