activitypub-academy/app/services/follow_remote_account_service.rb

82 lines
2.4 KiB
Ruby

class FollowRemoteAccountService < BaseService
# Find or create a local account for a remote user.
# When creating, look up the user's webfinger and fetch all
# important information from their feed
# @param [String] uri User URI in the form of username@domain
# @param [Boolean] subscribe Whether to initiate a PubSubHubbub subscription
# @return [Account]
def call(uri, subscribe = true)
username, domain = uri.split('@')
account = Account.where(username: username, domain: domain).first
if account.nil?
account = Account.new(username: username, domain: domain)
elsif account.subscribed?
return account
end
data = Goldfinger.finger("acct:#{uri}")
account.remote_url = data.link('http://schemas.google.com/g/2010#updates-from').href
account.salmon_url = data.link('salmon').href
account.url = data.link('http://webfinger.net/rel/profile-page').href
account.public_key = magic_key_to_pem(data.link('magic-public-key').href)
account.private_key = nil
feed = get_feed(account.remote_url)
hubs = feed.xpath('//xmlns:link[@rel="hub"]')
return nil if hubs.empty? || hubs.first.attribute('href').nil? || feed.at_xpath('/xmlns:feed/xmlns:author/xmlns:uri').nil?
account.uri = feed.at_xpath('/xmlns:feed/xmlns:author/xmlns:uri').content
account.hub_url = hubs.first.attribute('href').value
get_profile(feed, account)
account.save!
if subscribe
account.secret = SecureRandom.hex
account.verify_token = SecureRandom.hex
subscription = account.subscription(subscription_url(account))
subscription.subscribe
account.save!
end
return account
rescue Goldfinger::Error, HTTP::Error
nil
end
private
def get_feed(url)
response = http_client.get(Addressable::URI.parse(url))
Nokogiri::XML(response)
end
def get_profile(xml, account)
author = xml.at_xpath('/xmlns:feed/xmlns:author')
update_remote_profile_service.(author, account)
end
def magic_key_to_pem(magic_key)
_, modulus, exponent = magic_key.split('.')
modulus, exponent = [modulus, exponent].map { |n| Base64.urlsafe_decode64(n).bytes.inject(0) { |num, byte| (num << 8) | byte } }
key = OpenSSL::PKey::RSA.new
key.n = modulus
key.e = exponent
key.to_pem
end
def update_remote_profile_service
@update_remote_profile_service ||= UpdateRemoteProfileService.new
end
def http_client
HTTP
end
end