I run into this issue, but not with patreon as sign in provider. Everything else seems exactly alike though, the issue is only on mobile devices.
I’m using the OIDC plugin to authenticate through, see: Discourse OpenID Connect, to authenticate with Okta.
From the discourse error logs that I can visit at https://discourse.example.com/logs/, I find an error that is logged whenever I reproduce our issue.
I read the following article about it: https://www.sohamkamani.com/blog/2017/01/14/web-security-cross-site-request-forgery/
I’m currently not confident about what goes on, but I guess that we are loosing a CSRF token at some point using the mobile auth flow.
This also makes me suspect that SiteSetting.patreon_login_ignore_state = true is an insecure way to bypass the issue we are having.
Error message
(oidc) Authentication failure! csrf_detected: OmniAuth::Strategies::OAuth2::CallbackError, csrf_detected | CSRF detected
Note that CSRF stands for Cross-Site Request Forgery. And from googling I learned that:
CSRF attacks target functionality that causes a state change on the server, such as changing the victim’s email address or password, or purchasing something.
Error stack trace
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/logster-2.0.1/lib/logster/logger.rb:101:in `add_with_opts'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/logster-2.0.1/lib/logster/logger.rb:52:in `add'
/usr/local/lib/ruby/2.5.0/logger.rb:545:in `error'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/omniauth-1.9.0/lib/omniauth/strategy.rb:163:in `log'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/omniauth-1.9.0/lib/omniauth/strategy.rb:486:in `fail!'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/omniauth-oauth2-1.6.0/lib/omniauth/strategies/oauth2.rb:71:in `callback_phase'
/var/www/discourse/plugins/discourse-openid-connect/lib/omniauth_open_id_connect.rb:97:in `callback_phase'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/omniauth-1.9.0/lib/omniauth/strategy.rb:238:in `callback_call'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/omniauth-1.9.0/lib/omniauth/strategy.rb:189:in `call!'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/omniauth-1.9.0/lib/omniauth/strategy.rb:169:in `call'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/omniauth-1.9.0/lib/omniauth/strategy.rb:192:in `call!'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/omniauth-1.9.0/lib/omniauth/strategy.rb:169:in `call'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/omniauth-1.9.0/lib/omniauth/strategy.rb:192:in `call!'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/omniauth-1.9.0/lib/omniauth/strategy.rb:169:in `call'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/omniauth-1.9.0/lib/omniauth/strategy.rb:192:in `call!'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/omniauth-1.9.0/lib/omniauth/strategy.rb:169:in `call'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/omniauth-1.9.0/lib/omniauth/strategy.rb:192:in `call!'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/omniauth-1.9.0/lib/omniauth/strategy.rb:169:in `call'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/omniauth-1.9.0/lib/omniauth/strategy.rb:192:in `call!'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/omniauth-1.9.0/lib/omniauth/strategy.rb:169:in `call'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/omniauth-1.9.0/lib/omniauth/strategy.rb:192:in `call!'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/omniauth-1.9.0/lib/omniauth/strategy.rb:169:in `call'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/omniauth-1.9.0/lib/omniauth/builder.rb:64:in `call'
/var/www/discourse/lib/middleware/omniauth_bypass_middleware.rb:30:in `call'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/rack-2.0.6/lib/rack/tempfile_reaper.rb:15:in `call'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/rack-2.0.6/lib/rack/conditional_get.rb:25:in `call'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/rack-2.0.6/lib/rack/head.rb:12:in `call'
/var/www/discourse/lib/content_security_policy/middleware.rb:12:in `call'
/var/www/discourse/lib/middleware/anonymous_cache.rb:214:in `call'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/rack-2.0.6/lib/rack/session/abstract/id.rb:232:in `context'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/rack-2.0.6/lib/rack/session/abstract/id.rb:226:in `call'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/actionpack-5.2.2/lib/action_dispatch/middleware/cookies.rb:670:in `call'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/actionpack-5.2.2/lib/action_dispatch/middleware/callbacks.rb:28:in `block in call'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/activesupport-5.2.2/lib/active_support/callbacks.rb:98:in `run_callbacks'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/actionpack-5.2.2/lib/action_dispatch/middleware/callbacks.rb:26:in `call'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/actionpack-5.2.2/lib/action_dispatch/middleware/debug_exceptions.rb:61:in `call'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/actionpack-5.2.2/lib/action_dispatch/middleware/show_exceptions.rb:33:in `call'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/logster-2.0.1/lib/logster/middleware/reporter.rb:30:in `call'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/railties-5.2.2/lib/rails/rack/logger.rb:38:in `call_app'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/railties-5.2.2/lib/rails/rack/logger.rb:28:in `call'
/var/www/discourse/config/initializers/100-quiet_logger.rb:16:in `call'
/var/www/discourse/config/initializers/100-silence_logger.rb:29:in `call'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/actionpack-5.2.2/lib/action_dispatch/middleware/remote_ip.rb:81:in `call'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/actionpack-5.2.2/lib/action_dispatch/middleware/request_id.rb:27:in `call'
/var/www/discourse/lib/middleware/enforce_hostname.rb:17:in `call'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/rack-2.0.6/lib/rack/method_override.rb:22:in `call'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/actionpack-5.2.2/lib/action_dispatch/middleware/executor.rb:14:in `call'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/rack-2.0.6/lib/rack/sendfile.rb:111:in `call'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/rack-mini-profiler-1.0.2/lib/mini_profiler/profiler.rb:171:in `call'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/message_bus-2.2.0/lib/message_bus/rack/middleware.rb:57:in `call'
/var/www/discourse/lib/middleware/request_tracker.rb:182:in `call'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/railties-5.2.2/lib/rails/engine.rb:524:in `call'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/railties-5.2.2/lib/rails/railtie.rb:190:in `public_send'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/railties-5.2.2/lib/rails/railtie.rb:190:in `method_missing'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/rack-2.0.6/lib/rack/urlmap.rb:68:in `block in call'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/rack-2.0.6/lib/rack/urlmap.rb:53:in `each'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/rack-2.0.6/lib/rack/urlmap.rb:53:in `call'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/unicorn-5.4.1/lib/unicorn/http_server.rb:606:in `process_client'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/unicorn-5.4.1/lib/unicorn/http_server.rb:701:in `worker_loop'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/unicorn-5.4.1/lib/unicorn/http_server.rb:549:in `spawn_missing_workers'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/unicorn-5.4.1/lib/unicorn/http_server.rb:142:in `start'
/var/www/discourse/vendor/bundle/ruby/2.5.0/gems/unicorn-5.4.1/bin/unicorn:126:in `<top (required)>'
/var/www/discourse/vendor/bundle/ruby/2.5.0/bin/unicorn:23:in `load'
/var/www/discourse/vendor/bundle/ruby/2.5.0/bin/unicorn:23:in `<main>'