forked from fedi/mastodon
a5a00d7f7a
* Fix email with empty domain name labels passing validation `EmailMxValidator` would allow empty labels because `Resolv::DNS` is particularly lenient about them, but the email would be invalid and unusable. * Add tests
66 lines
1.6 KiB
Ruby
66 lines
1.6 KiB
Ruby
# frozen_string_literal: true
|
|
|
|
require 'resolv'
|
|
|
|
class EmailMxValidator < ActiveModel::Validator
|
|
def validate(user)
|
|
return if user.email.blank?
|
|
|
|
domain = get_domain(user.email)
|
|
|
|
if domain.blank?
|
|
user.errors.add(:email, :invalid)
|
|
elsif domain.include?('..')
|
|
user.errors.add(:email, :invalid)
|
|
elsif !on_allowlist?(domain)
|
|
resolved_ips, resolved_domains = resolve_mx(domain)
|
|
|
|
if resolved_ips.empty?
|
|
user.errors.add(:email, :unreachable)
|
|
elsif on_blacklist?(resolved_domains, user.sign_up_ip)
|
|
user.errors.add(:email, :blocked)
|
|
end
|
|
end
|
|
end
|
|
|
|
private
|
|
|
|
def get_domain(value)
|
|
_, domain = value.split('@', 2)
|
|
|
|
return nil if domain.nil?
|
|
|
|
TagManager.instance.normalize_domain(domain)
|
|
rescue Addressable::URI::InvalidURIError
|
|
nil
|
|
end
|
|
|
|
def on_allowlist?(domain)
|
|
return false if Rails.configuration.x.email_domains_whitelist.blank?
|
|
|
|
Rails.configuration.x.email_domains_whitelist.include?(domain)
|
|
end
|
|
|
|
def resolve_mx(domain)
|
|
records = []
|
|
ips = []
|
|
|
|
Resolv::DNS.open do |dns|
|
|
dns.timeouts = 5
|
|
|
|
records = dns.getresources(domain, Resolv::DNS::Resource::IN::MX).to_a.map { |e| e.exchange.to_s }
|
|
|
|
([domain] + records).uniq.each do |hostname|
|
|
ips.concat(dns.getresources(hostname, Resolv::DNS::Resource::IN::A).to_a.map { |e| e.address.to_s })
|
|
ips.concat(dns.getresources(hostname, Resolv::DNS::Resource::IN::AAAA).to_a.map { |e| e.address.to_s })
|
|
end
|
|
end
|
|
|
|
[ips, records]
|
|
end
|
|
|
|
def on_blacklist?(domains, attempt_ip)
|
|
EmailDomainBlock.block?(domains, attempt_ip: attempt_ip)
|
|
end
|
|
end
|