Stalwart-mail+Discourse: POP3 EOF 도달 (다시)

POP3 Polling SSL Issue에서 이어서 논의합니다:

안녕하세요,

Discourse와 함께 새로운 Stalwart-mail POP3 지원을 테스트하고 있습니다…

DNS 레코드 완료
DNS Records
Type	Name	Contents
MX	hack2o.eu.	10 mx.z7l.eu.
CNAME	mail.hack2o.eu.	mx.z7l.eu.
TXT	202406e._domainkey.hack2o.eu.	v=DKIM1; k=ed25519; h=sha256; p=J7kVdkoSKjwJcdPOcqCvvR7YtJV3LtOKEQ09c00+/fY=
TXT	202406r._domainkey.hack2o.eu.	v=DKIM1; k=rsa; h=sha256; p=MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAuvXE8Nf0Q9C+/coc9RgACmoTwQ9OZMkJIuWxtT0fYr6UY3CYnjzOLp+VEKoqQA2OHfNM7Q3rQSw0ghjKcMW2OqzQKQAQTGrm3hvSjsJgQvUcgjHbZngpzfqBsCun6iONGuO33UJmzH4hpnm0ljLGiOw4wv6MA918wL71oZS7HWjYU9g31uasCVBpt0Ch1U6Vfs4/ejVSXbmvNb+BDQUU48E8SnpnZS6yLoMC7gByflVvoOlLvj8tV4HYdO74FXej4gUEUUacQUQPyWKDzHhhcuhG/nmoWOrbJyiTpoq4cflKTblg6wriBZ6XPXud2Og1U0SB1yPyEtV7q3b4ZLJ1AwIDAQAB
TXT	hack2o.eu.	v=spf1 mx ra=postmaster -all
SRV	_imaps._tcp.hack2o.eu.	0 1 143 mx.z7l.eu.
SRV	_imaps._tcp.hack2o.eu.	0 1 993 mx.z7l.eu.
SRV	_pop3s._tcp.hack2o.eu.	0 1 995 mx.z7l.eu.
SRV	_submissions._tcp.hack2o.eu.	0 1 465 mx.z7l.eu.
SRV	_submissions._tcp.hack2o.eu.	0 1 587 mx.z7l.eu.
CNAME	autoconfig.hack2o.eu.	mx.z7l.eu.
CNAME	autodiscover.hack2o.eu.	mx.z7l.eu.
CNAME	mta-sts.hack2o.eu.	mx.z7l.eu.
TXT	_mta-sts.hack2o.eu.	v=STSv1; id=16222476092926415687
TXT	_dmarc.hack2o.eu.	v=DMARC1; p=reject; rua=mailto:postmaster@hack2o.eu; ruf=mailto:postmaster@hack2o.eu
TXT	_smtp._tls.hack2o.eu.	v=TLSRPTv1; rua=mailto:postmaster@hack2o.eu
TLSA	_25._tcp.mail.hack2o.eu.	3 0 1 22eaf4d577f42a1ceeda1b8da12ab2c0eb20351b7e3f7035c2cac7dd700a3ab6
TLSA	_25._tcp.mail.hack2o.eu.	3 0 2 16c04cca276b0d880b843f35b8f8513b7b4157907cb19c5d5f36464ea5e04972e863f24a6cb18bcd39fe5cc0cff793d6a5225d8937654ab28b2c7096a12cd858
TLSA	_25._tcp.mail.hack2o.eu.	3 1 1 0a47742e724fe771934bbf9a5d9c721cf34b97135242042b9e0a2c030c634455
TLSA	_25._tcp.mail.hack2o.eu.	3 1 2 ab60f26c194e0467bade96dd1a0bffd5d465065b2740e577f28f889a019ec2b455af8b8a1b1bcd66b998bba91469c5c5430c0a9f52f27316b33f93997d48f3e7
TLSA	_25._tcp.mail.hack2o.eu.	2 0 1 76e9e288aafc0e37f4390cbf946aad997d5c1c901b3ce513d3d8fadbabe2ab85
TLSA	_25._tcp.mail.hack2o.eu.	2 0 2 afab698cbbbf892ebb555e09175056c1d4630fe7c350f44dcc6e71843d3b290df00d30ab4e356b630c69169d7633788338922fb637cf5b9f7be20a413eeaa518
TLSA	_25._tcp.mail.hack2o.eu.	2 1 1 d016e1fe311948aca64f2de44ce86c9a51ca041df6103bb52a88eb3f761f57d7
TLSA	_25._tcp.mail.hack2o.eu.	2 1 2 f8a2b4e23e82a4494e9998fcc4242bef1277656a118beede55ddfadcb82e20c5dc036dcb3b6c48d2ce04e362a9f477c82ad5a557b06b6f33b45ca6662b37c1c9

POP3 계정은 Thunderbird에서 정상적으로 작동하며, 구성도 자동으로 잘 발견됩니다.

그러나 Discourse는 TLS 1.3 우회책에도 불구하고 활성화에 실패합니다.

에러 메시지
Message

EOFError (end of file reached)
app/services/email_settings_validator.rb:55:in `validate_pop3'
lib/validators/pop3_polling_enabled_setting_validator.rb:35:in `authentication_works?'
lib/validators/pop3_polling_enabled_setting_validator.rb:15:in `valid_value?'
lib/site_settings/type_supervisor.rb:284:in `validate_value'
lib/site_settings/type_supervisor.rb:165:in `to_db_value'
lib/site_setting_extension.rb:368:in `add_override!'
lib/site_setting_extension.rb:609:in `block in setup_methods'
lib/site_setting_extension.rb:435:in `public_send'
lib/site_setting_extension.rb:435:in `set'
lib/site_setting_extension.rb:448:in `set_and_log'
app/controllers/admin/site_settings_controller.rb:56:in `update'
app/controllers/application_controller.rb:422:in `block in with_resolved_locale'
app/controllers/application_controller.rb:422:in `with_resolved_locale'
lib/middleware/omniauth_bypass_middleware.rb:64:in `call'
lib/content_security_policy/middleware.rb:12:in `call'
lib/middleware/anonymous_cache.rb:393:in `call'
lib/middleware/csp_script_nonce_injector.rb:12:in `call'
config/initializers/008-rack-cors.rb:14:in `call'
config/initializers/100-quiet_logger.rb:20:in `call'
config/initializers/100-silence_logger.rb:29:in `call'
lib/middleware/enforce_hostname.rb:24:in `call'
lib/middleware/request_tracker.rb:289:in `call'

Backtrace

/usr/local/lib/ruby/3.3.0/net/protocol.rb:237:in `rbuf_fill'
/usr/local/lib/ruby/3.3.0/net/protocol.rb:199:in `readuntil'
/usr/local/lib/ruby/3.3.0/net/protocol.rb:209:in `readline'
net-pop (0.1.2) lib/net/pop.rb:1000:in `recv_response'
net-pop (0.1.2) lib/net/pop.rb:996:in `get_response'
net-pop (0.1.2) lib/net/pop.rb:984:in `block in quit'
net-pop (0.1.2) lib/net/pop.rb:1016:in `critical'
net-pop (0.1.2) lib/net/pop.rb:984:in `quit'
net-pop (0.1.2) lib/net/pop.rb:603:in `do_finish'
net-pop (0.1.2) lib/net/pop.rb:533:in `start'
net-pop (0.1.2) lib/net/pop.rb:316:in `auth_only'
app/services/email_settings_validator.rb:55:in `validate_pop3'
lib/validators/pop3_polling_enabled_setting_validator.rb:35:in `authentication_works?'
lib/validators/pop3_polling_enabled_setting_validator.rb:15:in `valid_value?'
lib/site_settings/type_supervisor.rb:284:in `validate_value'
lib/site_settings/type_supervisor.rb:165:in `to_db_value'
lib/site_setting_extension.rb:368:in `add_override!'
lib/site_setting_extension.rb:609:in `block in setup_methods'
lib/site_setting_extension.rb:435:in `public_send'
lib/site_setting_extension.rb:435:in `set'
lib/site_setting_extension.rb:448:in `set_and_log'
app/controllers/admin/site_settings_controller.rb:56:in `update'
actionpack (7.0.8.4) lib/action_controller/metal/basic_implicit_render.rb:6:in `send_action'
actionpack (7.0.8.4) lib/abstract_controller/base.rb:215:in `process_action'
actionpack (7.0.8.4) lib/action_controller/metal/rendering.rb:165:in `process_action'
actionpack (7.0.8.4) lib/abstract_controller/callbacks.rb:234:in `block in process_action'
activesupport (7.0.8.4) lib/active_support/callbacks.rb:118:in `block in run_callbacks'
app/controllers/application_controller.rb:422:in `block in with_resolved_locale'
i18n (1.14.5) lib/i18n.rb:351:in `with_locale'
app/controllers/application_controller.rb:422:in `with_resolved_locale'
activesupport (7.0.8.4) lib/active_support/callbacks.rb:127:in `block in run_callbacks'
activesupport (7.0.8.4) lib/active_support/callbacks.rb:138:in `run_callbacks'
actionpack (7.0.8.4) lib/abstract_controller/callbacks.rb:233:in `process_action'
actionpack (7.0.8.4) lib/action_controller/metal/rescue.rb:23:in `process_action'
actionpack (7.0.8.4) lib/action_controller/metal/instrumentation.rb:67:in `block in process_action'
activesupport (7.0.8.4) lib/active_support/notifications.rb:206:in `block in instrument'
activesupport (7.0.8.4) lib/active_support/notifications/instrumenter.rb:24:in `instrument'
activesupport (7.0.8.4) lib/active_support/notifications.rb:206:in `instrument'
actionpack (7.0.8.4) lib/action_controller/metal/instrumentation.rb:66:in `process_action'
actionpack (7.0.8.4) lib/action_controller/metal/params_wrapper.rb:259:in `process_action'
activerecord (7.0.8.4) lib/active_record/railties/controller_runtime.rb:27:in `process_action'
actionpack (7.0.8.4) lib/abstract_controller/base.rb:151:in `process'
actionview (7.0.8.4) lib/action_view/rendering.rb:39:in `process'
rack-mini-profiler (3.3.1) lib/mini_profiler/profiling_methods.rb:115:in `block in profile_method'
actionpack (7.0.8.4) lib/action_controller/metal.rb:188:in `dispatch'
actionpack (7.0.8.4) lib/action_controller/metal.rb:251:in `dispatch'
actionpack (7.0.8.4) lib/action_dispatch/routing/route_set.rb:49:in `dispatch'
actionpack (7.0.8.4) lib/action_dispatch/routing/route_set.rb:32:in `serve'
actionpack (7.0.8.4) lib/action_dispatch/routing/mapper.rb:18:in `block in <class:Constraints>'
actionpack (7.0.8.4) lib/action_dispatch/routing/mapper.rb:48:in `serve'
actionpack (7.0.8.4) lib/action_dispatch/journey/router.rb:50:in `block in serve'
actionpack (7.0.8.4) lib/action_dispatch/journey/router.rb:32:in `each'
actionpack (7.0.8.4) lib/action_dispatch/journey/router.rb:32:in `serve'
actionpack (7.0.8.4) lib/action_dispatch/routing/route_set.rb:852:in `call'
lib/middleware/omniauth_bypass_middleware.rb:64:in `call'
rack (2.2.9) lib/rack/tempfile_reaper.rb:15:in `call'
rack (2.2.9) lib/rack/conditional_get.rb:40:in `call'
rack (2.2.9) lib/rack/head.rb:12:in `call'
actionpack (7.0.8.4) lib/action_dispatch/http/permissions_policy.rb:38:in `call'
lib/content_security_policy/middleware.rb:12:in `call'
lib/middleware/anonymous_cache.rb:393:in `call'
lib/middleware/csp_script_nonce_injector.rb:12:in `call'
config/initializers/008-rack-cors.rb:14:in `call'
rack (2.2.9) lib/rack/session/abstract/id.rb:266:in `context'
rack (2.2.9) lib/rack/session/abstract/id.rb:260:in `call'
actionpack (7.0.8.4) lib/action_dispatch/middleware/cookies.rb:704:in `call'
actionpack (7.0.8.4) lib/action_dispatch/middleware/callbacks.rb:27:in `block in call'
activesupport (7.0.8.4) lib/active_support/callbacks.rb:99:in `run_callbacks'
actionpack (7.0.8.4) lib/action_dispatch/middleware/callbacks.rb:26:in `call'
actionpack (7.0.8.4) lib/action_dispatch/middleware/debug_exceptions.rb:28:in `call'
actionpack (7.0.8.4) lib/action_dispatch/middleware/show_exceptions.rb:29:in `call'
logster (2.19.1) lib/logster/middleware/reporter.rb:40:in `call'
railties (7.0.8.4) lib/rails/rack/logger.rb:40:in `call_app'
railties (7.0.8.4) lib/rails/rack/logger.rb:27:in `call'
config/initializers/100-quiet_logger.rb:20:in `call'
config/initializers/100-silence_logger.rb:29:in `call'
actionpack (7.0.8.4) lib/action_dispatch/middleware/remote_ip.rb:93:in `call'
actionpack (7.0.8.4) lib/action_dispatch/middleware/request_id.rb:26:in `call'
lib/middleware/enforce_hostname.rb:24:in `call'
rack (2.2.9) lib/rack/method_override.rb:24:in `call'
actionpack (7.0.8.4) lib/action_dispatch/middleware/executor.rb:14:in `call'
rack (2.2.9) lib/rack/sendfile.rb:110:in `call'
actionpack (7.0.8.4) lib/action_dispatch/middleware/host_authorization.rb:131:in `call'
rack-mini-profiler (3.3.1) lib/mini_profiler.rb:334:in `call'
message_bus (4.3.8) lib/message_bus/rack/middleware.rb:60:in `call'
lib/middleware/request_tracker.rb:289:in `call'
railties (7.0.8.4) lib/rails/engine.rb:530:in `call'
railties (7.0.8.4) lib/rails/railtie.rb:226:in `public_send'
railties (7.0.8.4) lib/rails/railtie.rb:226:in `method_missing'
rack (2.2.9) lib/rack/urlmap.rb:74:in `block in call'
rack (2.2.9) lib/rack/urlmap.rb:58:in `each'
rack (2.2.9) lib/rack/urlmap.rb:58:in `call'
unicorn (6.1.0) lib/unicorn/http_server.rb:634:in `process_client'
unicorn (6.1.0) lib/unicorn/http_server.rb:739:in `worker_loop'
unicorn (6.1.0) lib/unicorn/http_server.rb:547:in `spawn_missing_workers'
unicorn (6.1.0) lib/unicorn/http_server.rb:143:in `start'
unicorn (6.1.0) bin/unicorn:128:in `<top (required)>'
vendor/bundle/ruby/3.3.0/bin/unicorn:25:in `load'
vendor/bundle/ruby/3.3.0/bin/unicorn:25:in `<main>'

Env

HTTP HOSTS: forum.hack2o.eu

이 오류는 순수 Ruby Net::POP3로 재현할 수 있지만, 인증은 실패하지 않습니다. 단순히 의미 없는 OpenSSL 오류일 뿐입니다. openssl c_client를 직접 연결하면 TLS1.2와 TLS1.3 모두 작동합니다. 현재 OpenSSL 경고가 발생하는 연결 해제 시점을 제외하고는 모든 것이 정상적으로 작동하는 것으로 보이기 때문에, 여기서 무엇을 해야 할지 확실하지 않습니다.


다음은 최소한의 Ruby 테스트입니다:

Net::POP3 테스트
require 'net/pop'

puts "Testing POP3 connection for #{ENV['POP3_USER']} on #{ENV['POP3_HOST']}"

Net::POP3.enable_ssl

pop = Net::POP3.new(ENV['POP3_HOST'], 995)

print " using SSL: ", pop.use_ssl?? "yes":"no", "\n"

begin
  pop.auth_only(ENV['POP3_USER'], ENV['POP3_PASS'])
  puts "Authentication succeeded!"
rescue Net::POPAuthenticationError => err
  puts "Authentication failed."
#  p ENV['POP3_USER']
#  p ENV['POP3_PASS']
#  p pop
  exit
end

enable_ssl에 대한 ssl_params를 다음과 같이 설정하여 테스트한 결과도 동일했습니다:

  • min_version: OpenSSL::SSL::TLS1_3_VERSION
  • max_version: OpenSSL::SSL::TLS1_2_VERSION

다음은 OpenSSL 세션입니다(TLS1.2와 1.3 모두 동일):

openssl s_client -quiet -tls1_3 mail.example:995
depth=2 C = US, O = Internet Security Research Group, CN = ISRG Root X1
verify return:1
depth=1 C = US, O = Let's Encrypt, CN = E5
verify return:1
depth=0 CN = mail.example
verify return:1
+OK Stalwart POP3 at your service.
USER user@mail.example
+OK user@mail.example is a valid mailbox
PASS redacted
+OK Authentication successful
QUIT
40771049E17F0000:error:0A000126:SSL routines:ssl3_read_n:unexpected eof while reading:../ssl/record/rec_layer_s3.c:303:
openssl s_client -quiet -tls1_2 mail.example:995
depth=2 C = US, O = Internet Security Research Group, CN = ISRG Root X1
verify return:1
depth=1 C = US, O = Let's Encrypt, CN = E5
verify return:1
depth=0 CN = mail.example
verify return:1
+OK Stalwart POP3 at your service.
USER user@mail.example
+OK user@mail.example is a valid mailbox
PASS redacted
+OK Authentication successful
QUIT
40771049E17F0000:error:0A000126:SSL routines:ssl3_read_n:unexpected eof while reading:../ssl/record/rec_layer_s3.c:303:

다른 구현체들은 OpenSSL 오류를 발생시키지 않는 이유가 무엇인지 궁금합니다.

이것은 Stalwart-mail의 버그라고 생각하며, 검토를 위해 이 토픽에 보고할 것입니다.

stalwart에 이 문제를 보고한 장소를 찾을 수 없어서, 여기에서 보고했습니다: [bug]: discourse pop3 polling doesn't work · Issue #567 · stalwartlabs/stalwart · GitHub

@programmerjake 님, 감사합니다. 작성해주신 수정 사항 POP3 QUIT must write a response by programmerjake · Pull Request #568 · stalwartlabs/stalwart · GitHub 이 폴링 문제를 해결해 주었습니다.

(어떻게 디버깅해야 하는지, 그리고 실제 문제를 어떻게 파악해야 하는지 몰라서 Matrix 채널에 문제를 보고했습니다.)