38 lines
957 B
Ruby
38 lines
957 B
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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user.errors.add(:email, I18n.t('users.invalid_email')) if invalid_mx?(user.email)
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end
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private
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def invalid_mx?(value)
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_, domain = value.split('@', 2)
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return true if domain.nil?
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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 = 1
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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.empty? || on_blacklist?(hostnames + ips)
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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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