forked from fedi/mastodon
051efed5ed
* Bypass MX validation for explicitly allowed domains This spares some lookups and prevent issues in some edge cases with local domains. * Add tests * Fix test
64 lines
1.5 KiB
Ruby
64 lines
1.5 KiB
Ruby
# frozen_string_literal: true
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require 'resolv'
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class EmailMxValidator < ActiveModel::Validator
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def validate(user)
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return if user.email.blank?
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domain = get_domain(user.email)
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if domain.blank?
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user.errors.add(:email, :invalid)
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elsif !on_allowlist?(domain)
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ips, hostnames = resolve_mx(domain)
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if ips.empty?
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user.errors.add(:email, :unreachable)
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elsif on_blacklist?(hostnames + ips)
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user.errors.add(:email, :blocked)
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end
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end
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end
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private
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def get_domain(value)
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_, domain = value.split('@', 2)
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return nil if domain.nil?
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TagManager.instance.normalize_domain(domain)
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rescue Addressable::URI::InvalidURIError
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nil
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end
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def on_allowlist?(domain)
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return false if Rails.configuration.x.email_domains_whitelist.blank?
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Rails.configuration.x.email_domains_whitelist.include?(domain)
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end
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def resolve_mx(domain)
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hostnames = []
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ips = []
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Resolv::DNS.open do |dns|
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dns.timeouts = 5
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hostnames = dns.getresources(domain, Resolv::DNS::Resource::IN::MX).to_a.map { |e| e.exchange.to_s }
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([domain] + hostnames).uniq.each do |hostname|
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ips.concat(dns.getresources(hostname, Resolv::DNS::Resource::IN::A).to_a.map { |e| e.address.to_s })
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ips.concat(dns.getresources(hostname, Resolv::DNS::Resource::IN::AAAA).to_a.map { |e| e.address.to_s })
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end
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end
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[ips, hostnames]
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end
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def on_blacklist?(values)
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EmailDomainBlock.where(domain: values.uniq).any?
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end
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end
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