Improve email address validation (#14565)

* Increase DNS timeout from 1 second to 5 seconds for MX check

1 seconds is rather short when using a recursive DNS resolver which
hasn't got a cached result already available. Use 5 seconds instead,
which is the timeout value we use for outgoing HTTP queries.

* Add more precise error messages for invalid e-mail addresses
master
ThibG 4 years ago committed by GitHub
parent 7dc4c74265
commit 8d217d7231
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  1. 2
      app/controllers/admin/email_domain_blocks_controller.rb
  2. 2
      app/validators/blacklisted_email_validator.rb
  3. 30
      app/validators/email_mx_validator.rb
  4. 2
      config/locales/en.yml
  5. 2
      lib/mastodon/email_domain_blocks_cli.rb
  6. 4
      spec/validators/blacklisted_email_validator_spec.rb

@ -27,7 +27,7 @@ module Admin
ips = []
Resolv::DNS.open do |dns|
dns.timeouts = 1
dns.timeouts = 5
hostnames = dns.getresources(@email_domain_block.domain, Resolv::DNS::Resource::IN::MX).to_a.map { |e| e.exchange.to_s }

@ -6,7 +6,7 @@ class BlacklistedEmailValidator < ActiveModel::Validator
@email = user.email
user.errors.add(:email, I18n.t('users.invalid_email')) if blocked_email?
user.errors.add(:email, I18n.t('users.blocked_email_provider')) if blocked_email?
end
private

@ -4,22 +4,38 @@ require 'resolv'
class EmailMxValidator < ActiveModel::Validator
def validate(user)
user.errors.add(:email, I18n.t('users.invalid_email')) if invalid_mx?(user.email)
domain = get_domain(user.email)
if domain.nil?
user.errors.add(:email, I18n.t('users.invalid_email'))
else
ips, hostnames = resolve_mx(domain)
if ips.empty?
user.errors.add(:email, I18n.t('users.invalid_email_mx'))
elsif on_blacklist?(hostnames + ips)
user.errors.add(:email, I18n.t('users.blocked_email_provider'))
end
end
end
private
def invalid_mx?(value)
def get_domain(value)
_, domain = value.split('@', 2)
return true if domain.nil?
return nil if domain.nil?
TagManager.instance.normalize_domain(domain)
rescue Addressable::URI::InvalidURIError
nil
end
domain = TagManager.instance.normalize_domain(domain)
def resolve_mx(domain)
hostnames = []
ips = []
Resolv::DNS.open do |dns|
dns.timeouts = 1
dns.timeouts = 5
hostnames = dns.getresources(domain, Resolv::DNS::Resource::IN::MX).to_a.map { |e| e.exchange.to_s }
@ -29,9 +45,7 @@ class EmailMxValidator < ActiveModel::Validator
end
end
ips.empty? || on_blacklist?(hostnames + ips)
rescue Addressable::URI::InvalidURIError
true
[ips, hostnames]
end
def on_blacklist?(values)

@ -1325,9 +1325,11 @@ en:
tips: Tips
title: Welcome aboard, %{name}!
users:
blocked_email_provider: This e-mail provider isn't allowed
follow_limit_reached: You cannot follow more than %{limit} people
generic_access_help_html: Trouble accessing your account? You may get in touch with %{email} for assistance
invalid_email: The e-mail address is invalid
invalid_email_mx: The e-mail address does not seem to exist
invalid_otp_token: Invalid two-factor code
invalid_sign_in_token: Invalid security code
otp_lost_help_html: If you lost access to both, you may get in touch with %{email}

@ -63,7 +63,7 @@ module Mastodon
ips = []
Resolv::DNS.open do |dns|
dns.timeouts = 1
dns.timeouts = 5
hostnames = dns.getresources(email_domain_block.domain, Resolv::DNS::Resource::IN::MX).to_a.map { |e| e.exchange.to_s }
([email_domain_block.domain] + hostnames).uniq.each do |hostname|

@ -17,7 +17,7 @@ RSpec.describe BlacklistedEmailValidator, type: :validator do
let(:blocked_email) { true }
it 'calls errors.add' do
expect(errors).to have_received(:add).with(:email, I18n.t('users.invalid_email'))
expect(errors).to have_received(:add).with(:email, I18n.t('users.blocked_email_provider'))
end
end
@ -25,7 +25,7 @@ RSpec.describe BlacklistedEmailValidator, type: :validator do
let(:blocked_email) { false }
it 'not calls errors.add' do
expect(errors).not_to have_received(:add).with(:email, I18n.t('users.invalid_email'))
expect(errors).not_to have_received(:add).with(:email, I18n.t('users.blocked_email_provider'))
end
end
end

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