HTTP signatures (#4146)

* Add Request class with HTTP signature generator

Spec: https://tools.ietf.org/html/draft-cavage-http-signatures-06

* Add HTTP signature verification concern

* Add test for SignatureVerification concern

* Add basic test for Request class

* Make PuSH subscribe/unsubscribe requests use new Request class

Accidentally fix lease_seconds not being set and sent properly, and
change the new minimum subscription duration to 1 day

* Make all PuSH workers use new Request class

* Make Salmon sender use new Request class

* Make FetchLinkService use new Request class

* Make FetchAtomService use the new Request class

* Make Remotable use the new Request class

* Make ResolveRemoteAccountService use the new Request class

* Add more tests

* Allow +-30 seconds window for signed request to remain valid

* Disable time window validation for signed requests, restore 7 days
as PuSH subscription duration (which was previous default due to a bug)
This commit is contained in:
Eugen Rochko 2017-07-14 20:41:49 +02:00 committed by GitHub
parent c1f201c49a
commit 1618b68bfa
23 changed files with 379 additions and 90 deletions

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@ -2,6 +2,7 @@
class AccountsController < ApplicationController class AccountsController < ApplicationController
include AccountControllerConcern include AccountControllerConcern
include SignatureVerification
def show def show
respond_to do |format| respond_to do |format|

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@ -42,7 +42,7 @@ class Api::SubscriptionsController < Api::BaseController
end end
def lease_seconds_or_default def lease_seconds_or_default
(params['hub.lease_seconds'] || 86_400).to_i.seconds (params['hub.lease_seconds'] || 1.day).to_i.seconds
end end
def set_account def set_account

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@ -0,0 +1,87 @@
# frozen_string_literal: true
# Implemented according to HTTP signatures (Draft 6)
# <https://tools.ietf.org/html/draft-cavage-http-signatures-06>
module SignatureVerification
extend ActiveSupport::Concern
def signed_request?
request.headers['Signature'].present?
end
def signed_request_account
return @signed_request_account if defined?(@signed_request_account)
unless signed_request?
@signed_request_account = nil
return
end
raw_signature = request.headers['Signature']
signature_params = {}
raw_signature.split(',').each do |part|
parsed_parts = part.match(/([a-z]+)="([^"]+)"/i)
next if parsed_parts.nil? || parsed_parts.size != 3
signature_params[parsed_parts[1]] = parsed_parts[2]
end
if incompatible_signature?(signature_params)
@signed_request_account = nil
return
end
account = ResolveRemoteAccountService.new.call(signature_params['keyId'].gsub(/\Aacct:/, ''))
if account.nil?
@signed_request_account = nil
return
end
signature = Base64.decode64(signature_params['signature'])
compare_signed_string = build_signed_string(signature_params['headers'])
if account.keypair.public_key.verify(OpenSSL::Digest::SHA256.new, signature, compare_signed_string)
@signed_request_account = account
@signed_request_account
else
@signed_request_account = nil
end
end
private
def build_signed_string(signed_headers)
signed_headers = 'date' if signed_headers.blank?
signed_headers.split(' ').map do |signed_header|
if signed_header == Request::REQUEST_TARGET
"#{Request::REQUEST_TARGET}: #{request.method.downcase} #{request.path}"
else
"#{signed_header}: #{request.headers[to_header_name(signed_header)]}"
end
end.join("\n")
end
def matches_time_window?
begin
time_sent = DateTime.httpdate(request.headers['Date'])
rescue ArgumentError
return false
end
(Time.now.utc - time_sent).abs <= 30
end
def to_header_name(name)
name.split(/-/).map(&:capitalize).join('-')
end
def incompatible_signature?(signature_params)
signature_params['keyId'].blank? ||
signature_params['signature'].blank? ||
signature_params['algorithm'].blank? ||
signature_params['algorithm'] != 'rsa-sha256' ||
!signature_params['keyId'].start_with?('acct:')
end
end

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@ -2,6 +2,7 @@
class StreamEntriesController < ApplicationController class StreamEntriesController < ApplicationController
include Authorization include Authorization
include SignatureVerification
layout 'public' layout 'public'

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@ -1,17 +0,0 @@
# frozen_string_literal: true
module HttpHelper
def http_client(options = {})
timeout = { write: 10, connect: 10, read: 10 }.merge(options)
HTTP.headers(user_agent: user_agent)
.timeout(:per_operation, timeout)
.follow
end
private
def user_agent
@user_agent ||= "#{HTTP::Request::USER_AGENT} (Mastodon/#{Mastodon::Version}; +http://#{Rails.configuration.x.local_domain}/)"
end
end

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@ -1,11 +1,9 @@
# frozen_string_literal: true # frozen_string_literal: true
class ProviderDiscovery < OEmbed::ProviderDiscovery class ProviderDiscovery < OEmbed::ProviderDiscovery
extend HttpHelper
class << self class << self
def discover_provider(url, options = {}) def discover_provider(url, options = {})
res = http_client.get(url) res = Request.new(:get, url).perform
format = options[:format] format = options[:format]
raise OEmbed::NotFound, url if res.code != 200 || res.mime_type != 'text/html' raise OEmbed::NotFound, url if res.code != 200 || res.mime_type != 'text/html'

70
app/lib/request.rb Normal file
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@ -0,0 +1,70 @@
# frozen_string_literal: true
class Request
REQUEST_TARGET = '(request-target)'
include RoutingHelper
def initialize(verb, url, options = {})
@verb = verb
@url = Addressable::URI.parse(url).normalize
@options = options
@headers = {}
set_common_headers!
end
def on_behalf_of(account)
raise ArgumentError unless account.local?
@account = account
end
def add_headers(new_headers)
@headers.merge!(new_headers)
end
def perform
http_client.headers(headers).public_send(@verb, @url.to_s, @options)
end
def headers
(@account ? @headers.merge('Signature' => signature) : @headers).without(REQUEST_TARGET)
end
private
def set_common_headers!
@headers[REQUEST_TARGET] = "#{@verb} #{@url.path}"
@headers['User-Agent'] = user_agent
@headers['Host'] = @url.host
@headers['Date'] = Time.now.utc.httpdate
end
def signature
key_id = @account.to_webfinger_s
algorithm = 'rsa-sha256'
signature = Base64.strict_encode64(@account.keypair.sign(OpenSSL::Digest::SHA256.new, signed_string))
"keyId=\"#{key_id}\",algorithm=\"#{algorithm}\",headers=\"#{signed_headers}\",signature=\"#{signature}\""
end
def signed_string
@headers.map { |key, value| "#{key.downcase}: #{value}" }.join("\n")
end
def signed_headers
@headers.keys.join(' ').downcase
end
def user_agent
@user_agent ||= "#{HTTP::Request::USER_AGENT} (Mastodon/#{Mastodon::Version}; +#{root_url})"
end
def timeout
{ write: 10, connect: 10, read: 10 }
end
def http_client
HTTP.timeout(:per_operation, timeout).follow
end
end

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@ -130,7 +130,7 @@ class Account < ApplicationRecord
end end
def subscription(webhook_url) def subscription(webhook_url)
OStatus2::Subscription.new(remote_url, secret: secret, lease_seconds: 86_400 * 30, webhook: webhook_url, hub: hub_url) OStatus2::Subscription.new(remote_url, secret: secret, lease_seconds: 30.days.seconds, webhook: webhook_url, hub: hub_url)
end end
def save_with_optional_media! def save_with_optional_media!

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@ -1,7 +1,6 @@
# frozen_string_literal: true # frozen_string_literal: true
module Remotable module Remotable
include HttpHelper
extend ActiveSupport::Concern extend ActiveSupport::Concern
included do included do
@ -20,7 +19,7 @@ module Remotable
return if !%w(http https).include?(parsed_url.scheme) || parsed_url.host.empty? || self[attribute_name] == url return if !%w(http https).include?(parsed_url.scheme) || parsed_url.host.empty? || self[attribute_name] == url
begin begin
response = http_client.get(url) response = Request.new(:get, url).perform
return if response.code != 200 return if response.code != 200

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@ -16,8 +16,8 @@
# #
class Subscription < ApplicationRecord class Subscription < ApplicationRecord
MIN_EXPIRATION = 7.days.seconds.to_i MIN_EXPIRATION = 1.day.to_i
MAX_EXPIRATION = 30.days.seconds.to_i MAX_EXPIRATION = 30.days.to_i
belongs_to :account, required: true belongs_to :account, required: true

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@ -1,16 +1,14 @@
# frozen_string_literal: true # frozen_string_literal: true
class FetchAtomService < BaseService class FetchAtomService < BaseService
include HttpHelper
def call(url) def call(url)
return if url.blank? return if url.blank?
response = http_client.head(url) response = Request.new(:head, url).perform
Rails.logger.debug "Remote status HEAD request returned code #{response.code}" Rails.logger.debug "Remote status HEAD request returned code #{response.code}"
response = http_client.get(url) if response.code == 405 response = Request.new(:get, url).perform if response.code == 405
Rails.logger.debug "Remote status GET request returned code #{response.code}" Rails.logger.debug "Remote status GET request returned code #{response.code}"
@ -49,6 +47,6 @@ class FetchAtomService < BaseService
end end
def fetch(url) def fetch(url)
http_client.get(url).to_s Request.new(:get, url).perform.to_s
end end
end end

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@ -1,8 +1,6 @@
# frozen_string_literal: true # frozen_string_literal: true
class FetchLinkCardService < BaseService class FetchLinkCardService < BaseService
include HttpHelper
URL_PATTERN = %r{https?://\S+} URL_PATTERN = %r{https?://\S+}
def call(status) def call(status)
@ -13,7 +11,7 @@ class FetchLinkCardService < BaseService
url = url.to_s url = url.to_s
card = PreviewCard.where(status: status).first_or_initialize(status: status, url: url) card = PreviewCard.where(status: status).first_or_initialize(status: status, url: url)
res = http_client.head(url) res = Request.new(:head, url).perform
return if res.code != 200 || res.mime_type != 'text/html' return if res.code != 200 || res.mime_type != 'text/html'
@ -80,7 +78,7 @@ class FetchLinkCardService < BaseService
end end
def attempt_opengraph(card, url) def attempt_opengraph(card, url)
response = http_client.get(url) response = Request.new(:get, url).perform
return if response.code != 200 || response.mime_type != 'text/html' return if response.code != 200 || response.mime_type != 'text/html'

View File

@ -2,7 +2,6 @@
class ResolveRemoteAccountService < BaseService class ResolveRemoteAccountService < BaseService
include OStatus2::MagicKey include OStatus2::MagicKey
include HttpHelper
DFRN_NS = 'http://purl.org/macgirvin/dfrn/1.0' DFRN_NS = 'http://purl.org/macgirvin/dfrn/1.0'
@ -79,7 +78,7 @@ class ResolveRemoteAccountService < BaseService
end end
def get_feed(url) def get_feed(url)
response = http_client(write: 20, connect: 20, read: 50).get(Addressable::URI.parse(url).normalize) response = Request.new(:get, url).perform
raise Goldfinger::Error, "Feed attempt failed for #{url}: HTTP #{response.code}" unless response.code == 200 raise Goldfinger::Error, "Feed attempt failed for #{url}: HTTP #{response.code}" unless response.code == 200
[response.to_s, Nokogiri::XML(response)] [response.to_s, Nokogiri::XML(response)]
end end

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@ -12,13 +12,23 @@ class SendInteractionService < BaseService
return if block_notification? return if block_notification?
envelope = salmon.pack(@xml, @source_account.keypair) delivery = build_request.perform
delivery = salmon.post(@target_account.salmon_url, envelope)
raise "Delivery failed for #{target_account.salmon_url}: HTTP #{delivery.code}" unless delivery.code > 199 && delivery.code < 300 raise "Delivery failed for #{target_account.salmon_url}: HTTP #{delivery.code}" unless delivery.code > 199 && delivery.code < 300
end end
private private
def build_request
request = Request.new(:post, @target_account.salmon_url, body: envelope)
request.add_headers('Content-Type' => 'application/magic-envelope+xml')
request
end
def envelope
salmon.pack(@xml, @source_account.keypair)
end
def block_notification? def block_notification?
DomainBlock.blocked?(@target_account.domain) DomainBlock.blocked?(@target_account.domain)
end end

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@ -2,34 +2,54 @@
class SubscribeService < BaseService class SubscribeService < BaseService
def call(account) def call(account)
account.secret = SecureRandom.hex @account = account
@account.secret = SecureRandom.hex
@response = build_request.perform
subscription = account.subscription(api_subscription_url(account.id)) if response_failed_permanently?
response = subscription.subscribe
if response_failed_permanently?(response)
# We're not allowed to subscribe. Fail and move on. # We're not allowed to subscribe. Fail and move on.
account.secret = '' @account.secret = ''
account.save! @account.save!
elsif response_successful?(response) elsif response_successful?
# The subscription will be confirmed asynchronously. # The subscription will be confirmed asynchronously.
account.save! @account.save!
else else
# The response was either a 429 rate limit, or a 5xx error. # The response was either a 429 rate limit, or a 5xx error.
# We need to retry at a later time. Fail loudly! # We need to retry at a later time. Fail loudly!
raise "Subscription attempt failed for #{account.acct} (#{account.hub_url}): HTTP #{response.code}" raise "Subscription attempt failed for #{@account.acct} (#{@account.hub_url}): HTTP #{@response.code}"
end end
end end
private private
def build_request
request = Request.new(:post, @account.hub_url, form: subscription_params)
request.on_behalf_of(some_local_account) if some_local_account
request
end
def subscription_params
{
'hub.topic': @account.remote_url,
'hub.mode': 'subscribe',
'hub.callback': api_subscription_url(@account.id),
'hub.verify': 'async',
'hub.secret': @account.secret,
'hub.lease_seconds': 7.days.seconds,
}
end
def some_local_account
@some_local_account ||= Account.local.first
end
# Any response in the 3xx or 4xx range, except for 429 (rate limit) # Any response in the 3xx or 4xx range, except for 429 (rate limit)
def response_failed_permanently?(response) def response_failed_permanently?
(response.status.redirect? || response.status.client_error?) && !response.status.too_many_requests? (@response.status.redirect? || @response.status.client_error?) && !@response.status.too_many_requests?
end end
# Any response in the 2xx range # Any response in the 2xx range
def response_successful?(response) def response_successful?
response.status.success? @response.status.success?
end end
end end

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@ -2,17 +2,30 @@
class UnsubscribeService < BaseService class UnsubscribeService < BaseService
def call(account) def call(account)
subscription = account.subscription(api_subscription_url(account.id)) @account = account
response = subscription.unsubscribe @response = build_request.perform
unless response.status.success? Rails.logger.debug "PuSH unsubscribe for #{@account.acct} failed: #{@response.status}" unless @response.status.success?
Rails.logger.debug "PuSH unsubscribe for #{account.acct} failed: #{response.status}"
@account.secret = ''
@account.subscription_expires_at = nil
@account.save!
rescue HTTP::Error, OpenSSL::SSL::SSLError
Rails.logger.debug "PuSH subscription request for #{@account.acct} could not be made due to HTTP or SSL error"
end end
account.secret = '' private
account.subscription_expires_at = nil
account.save! def build_request
rescue HTTP::Error, OpenSSL::SSL::SSLError Request.new(:post, @account.hub_url, form: subscription_params)
Rails.logger.debug "PuSH subscription request for #{account.acct} could not be made due to HTTP or SSL error" end
def subscription_params
{
'hub.topic': @account.remote_url,
'hub.mode': 'unsubscribe',
'hub.callback': api_subscription_url(@account.id),
'hub.verify': 'async',
}
end end
end end

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@ -60,9 +60,7 @@ class Pubsubhubbub::ConfirmationWorker
end end
def callback_get_with_params def callback_get_with_params
HTTP.headers(user_agent: 'Mastodon/PubSubHubbub') Request.new(:get, subscription.callback_url, params: callback_params).perform
.timeout(:per_operation, write: 20, connect: 20, read: 50)
.get(subscription.callback_url, params: callback_params)
end end
def callback_response_body def callback_response_body
@ -71,10 +69,10 @@ class Pubsubhubbub::ConfirmationWorker
def callback_params def callback_params
{ {
'hub.topic' => account_url(subscription.account, format: :atom), 'hub.topic': account_url(subscription.account, format: :atom),
'hub.mode' => mode, 'hub.mode': mode,
'hub.challenge' => challenge, 'hub.challenge': challenge,
'hub.lease_seconds' => subscription.lease_seconds, 'hub.lease_seconds': subscription.lease_seconds,
} }
end end

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@ -33,9 +33,9 @@ class Pubsubhubbub::DeliveryWorker
end end
def callback_post_payload def callback_post_payload
HTTP.timeout(:per_operation, write: 50, connect: 20, read: 50) request = Request.new(:post, subscription.callback_url, body: payload)
.headers(headers) request.add_headers(headers)
.post(subscription.callback_url, body: payload) request.perform
end end
def blocked_domain? def blocked_domain?
@ -48,13 +48,12 @@ class Pubsubhubbub::DeliveryWorker
def headers def headers
{ {
'User-Agent' => 'Mastodon/PubSubHubbub',
'Content-Type' => 'application/atom+xml', 'Content-Type' => 'application/atom+xml',
'Link' => link_headers, 'Link' => link_header,
}.merge(signature_headers.to_h) }.merge(signature_headers.to_h)
end end
def link_headers def link_header
LinkHeader.new([hub_link_header, self_link_header]).to_s LinkHeader.new([hub_link_header, self_link_header]).to_s
end end

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@ -0,0 +1,74 @@
# frozen_string_literal: true
require 'rails_helper'
describe ApplicationController, type: :controller do
controller do
include SignatureVerification
def success
head 200
end
def alternative_success
head 200
end
end
before do
routes.draw { get 'success' => 'anonymous#success' }
end
context 'without signature header' do
before do
get :success
end
describe '#signed_request?' do
it 'returns false' do
expect(controller.signed_request?).to be false
end
end
describe '#signed_request_account' do
it 'returns nil' do
expect(controller.signed_request_account).to be_nil
end
end
end
context 'with signature header' do
let!(:author) { Fabricate(:account) }
before do
get :success
fake_request = Request.new(:get, request.url)
fake_request.on_behalf_of(author)
request.headers.merge!(fake_request.headers)
end
describe '#signed_request?' do
it 'returns true' do
expect(controller.signed_request?).to be true
end
end
describe '#signed_request_account' do
it 'returns an account' do
expect(controller.signed_request_account).to eq author
end
it 'returns nil when path does not match' do
request.path = '/alternative-path'
expect(controller.signed_request_account).to be_nil
end
it 'returns nil when method does not match' do
post :success
expect(controller.signed_request_account).to be_nil
end
end
end
end

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@ -1,13 +0,0 @@
# frozen_string_literal: true
require 'rails_helper'
describe HttpHelper do
describe 'http_client' do
it 'returns HTTP::Client with default options' do
options = helper.http_client.default_options
expect(options.headers['User-Agent']).to match /.+ \(Mastodon\/.+;\ \+http:\/\/cb6e6126\.ngrok\.io\/\)/
expect(options.timeout_options).to eq read_timeout: 10, write_timeout: 10, connect_timeout: 10
end
end
end

54
spec/lib/request_spec.rb Normal file
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@ -0,0 +1,54 @@
# frozen_string_literal: true
require 'rails_helper'
describe Request do
subject { Request.new(:get, 'http://example.com') }
describe '#headers' do
it 'returns user agent' do
expect(subject.headers['User-Agent']).to be_present
end
it 'returns the date header' do
expect(subject.headers['Date']).to be_present
end
it 'returns the host header' do
expect(subject.headers['Host']).to be_present
end
it 'does not return virtual request-target header' do
expect(subject.headers['(request-target)']).to be_nil
end
end
describe '#on_behalf_of' do
it 'when used, adds signature header' do
subject.on_behalf_of(Fabricate(:account))
expect(subject.headers['Signature']).to be_present
end
end
describe '#add_headers' do
it 'adds headers to the request' do
subject.add_headers('Test' => 'Foo')
expect(subject.headers['Test']).to eq 'Foo'
end
end
describe '#perform' do
before do
stub_request(:get, 'http://example.com')
subject.perform
end
it 'executes a HTTP request' do
expect(a_request(:get, 'http://example.com')).to have_been_made.once
end
it 'sets headers' do
expect(a_request(:get, 'http://example.com').with(headers: subject.headers)).to have_been_made
end
end
end

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@ -83,6 +83,6 @@ describe Pubsubhubbub::ConfirmationWorker do
end end
def http_headers def http_headers
{ 'Connection' => 'close', 'Host' => 'example.com', 'User-Agent' => 'Mastodon/PubSubHubbub' } { 'Connection' => 'close', 'Host' => 'example.com', 'User-Agent' => 'http.rb/2.2.2 (Mastodon/1.4.7; +https://cb6e6126.ngrok.io/)' }
end end
end end

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@ -59,7 +59,7 @@ describe Pubsubhubbub::DeliveryWorker do
'Content-Type' => 'application/atom+xml', 'Content-Type' => 'application/atom+xml',
'Host' => 'example.com', 'Host' => 'example.com',
'Link' => "<https://#{Rails.configuration.x.local_domain}/api/push>; rel=\"hub\", <https://#{Rails.configuration.x.local_domain}/users/#{subscription.account.username}.atom>; rel=\"self\"", 'Link' => "<https://#{Rails.configuration.x.local_domain}/api/push>; rel=\"hub\", <https://#{Rails.configuration.x.local_domain}/users/#{subscription.account.username}.atom>; rel=\"self\"",
'User-Agent' => 'Mastodon/PubSubHubbub', 'User-Agent' => 'http.rb/2.2.2 (Mastodon/1.4.7; +https://cb6e6126.ngrok.io/)',
}.tap do |basic| }.tap do |basic|
known_digest = OpenSSL::HMAC.hexdigest(OpenSSL::Digest.new('sha1'), subscription.secret.to_s, payload) known_digest = OpenSSL::HMAC.hexdigest(OpenSSL::Digest.new('sha1'), subscription.secret.to_s, payload)
basic.merge('X-Hub-Signature' => "sha1=#{known_digest}") if subscription.secret? basic.merge('X-Hub-Signature' => "sha1=#{known_digest}") if subscription.secret?