External User Support with IMAP not working

Steps to reproduce

Activate External Users App
Configure IMAP Authentication: cat /var/www/nextcloud/config/imapauth.config.php :

<?php $CONFIG = array( "user_backends" => array ( 0 => array ( "class" => "OC_User_IMAP", "arguments" => array ( 0 => '{imap.server.com:993/imap/ssl/readonly}' ), ), ), ); ?>

Try to login

Expected behaviour

Logs in

Actual behaviour

Nothing happens, this in log :

Error PHP Cannot modify header information - headers already sent by (output started at /var/www/nextcloud/config/imapauth.config.php:13) at /var/www/nextcloud/lib/private/Session/CryptoWrapper.php#89 2018-08-08T19:00:04+0100 Error PHP Cannot modify header information - headers already sent by (output started at /var/www/nextcloud/config/imapauth.config.php:13) at /var/www/nextcloud/lib/base.php#520 2018-08-08T19:00:03+0100 Error PHP Cannot modify header information - headers already sent by (output started at /var/www/nextcloud/config/imapauth.config.php:13) at /var/www/nextcloud/lib/base.php#520 2018-08-08T19:00:03+0100 Error PHP Cannot modify header information - headers already sent by (output started at /var/www/nextcloud/config/imapauth.config.php:13) at /var/www/nextcloud/lib/private/legacy/response.php#271 2018-08-08T19:00:03+0100

Server configuration detail

Operating system: Linux 4.15.0-30-generic #32-Ubuntu SMP Thu Jul 26 17:42:43 UTC 2018 x86_64

Webserver: Apache/2.4.34 (Ubuntu) (fpm-fcgi)

Database: pgsql PostgreSQL 10.4 (Ubuntu 10.4-0ubuntu0.18.04) on x86_64-pc-linux-gnu, compiled by gcc (Ubuntu 7.3.0-16ubuntu3) 7.3.0, 64-bit

PHP version: 7.2.7-0ubuntu0.18.04.2 Modules loaded: Core, date, libxml, openssl, pcre, zlib, filter, hash, Reflection, SPL, sodium, session, standard, cgi-fcgi, PDO, xml, bz2, calendar, ctype, curl, dom, mbstring, fileinfo, ftp, gd, gettext, gmp, iconv, igbinary, imagick, imap, intl, json, ldap, exif, pdo_pgsql, pgsql, Phar, posix, readline, redis, shmop, SimpleXML, smbclient, soap, sockets, sysvmsg, sysvsem, sysvshm, tokenizer, wddx, xmlreader, xmlwriter, xsl, zip, libsmbclient, Zend OPcache

Nextcloud version: 13.0.5 - 13.0.5.2

Updated from an older Nextcloud/ownCloud or fresh install: fresh

Where did you install Nextcloud from: official vm

Signing status

Array

List of activated apps

``` Enabled: - activity: 2.6.1 - caniupdate: 0.1.3 - comments: 1.3.0 - dav: 1.4.7 - encryption: 2.0.0 - federatedfilesharing: 1.3.1 - federation: 1.3.0 - files: 1.8.0 - files_pdfviewer: 1.2.1 - files_sharing: 1.5.0 - files_texteditor: 2.5.1 - files_trashbin: 1.3.0 - files_versions: 1.6.0 - files_videoplayer: 1.2.0 - firstrunwizard: 2.2.1 - gallery: 18.0.0 - issuetemplate: 0.3.0 - logreader: 2.0.0 - lookup_server_connector: 1.1.0 - nextcloud_announcements: 1.2.0 - notifications: 2.1.2 - oauth2: 1.1.1 - onlyoffice: 1.3.0 - password_policy: 1.3.0 - provisioning_api: 1.3.0 - registration: 0.4.3 - serverinfo: 1.3.0 - sharebymail: 1.3.0 - spreed: 3.2.5 - survey_client: 1.1.0 - systemtags: 1.3.0 - theming: 1.4.5 - twofactor_backupcodes: 1.2.3 - twofactor_totp: 1.4.1 - updatenotification: 1.3.0 - user_external: 0.4 - user_ldap: 1.3.1 - workflowengine: 1.3.0 Disabled: - admin_audit - files_external - user_saml ```

Configuration (config/config.php)

``` { "passwordsalt": "***REMOVED SENSITIVE VALUE***", "secret": "***REMOVED SENSITIVE VALUE***", "trusted_domains": [ "localhost", "77.235.58.186", "XXX", "XXX" ], "datadirectory": "***REMOVED SENSITIVE VALUE***", "overwrite.cli.url": "XXX", "dbtype": "pgsql", "version": "13.0.5.2", "dbname": "***REMOVED SENSITIVE VALUE***", "dbhost": "***REMOVED SENSITIVE VALUE***", "dbport": "", "dbtableprefix": "oc_", "dbuser": "***REMOVED SENSITIVE VALUE***", "dbpassword": "***REMOVED SENSITIVE VALUE***", "installed": true, "instanceid": "***REMOVED SENSITIVE VALUE***", "mail_smtpmode": "smtp", "log_rotate_size": "10485760", "memcache.local": "\\OC\\Memcache\\Redis", "filelocking.enabled": true, "memcache.distributed": "\\OC\\Memcache\\Redis", "memcache.locking": "\\OC\\Memcache\\Redis", "redis": { "host": "***REMOVED SENSITIVE VALUE***", "port": 0, "timeout": 0.5, "dbindex": 0, "password": "***REMOVED SENSITIVE VALUE***" }, "htaccess.RewriteBase": "\/", "loglevel": "2", "log_type": "file", "logfile": "\/mnt\/ncdata\/nextcloud.log", "logtimezone": "Europe\/Lisbon", "maintenance": false, "mail_smtpauthtype": "LOGIN", "mail_smtpauth": 1, "mail_from_address": "***REMOVED SENSITIVE VALUE***", "mail_domain": "***REMOVED SENSITIVE VALUE***", "mail_smtphost": "***REMOVED SENSITIVE VALUE***", "mail_smtpname": "***REMOVED SENSITIVE VALUE***", "mail_smtppassword": "***REMOVED SENSITIVE VALUE***", "ldapIgnoreNamingRules": false, "ldapProviderFactory": "\\OCA\\User_LDAP\\LDAPProviderFactory" } ```

Are you using external storage, if yes which one: local zfs

Are you using encryption: yes

Are you using an external user-backend, if yes which one: IMAP

Client configuration

Browser: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/67.0.3396.99 Safari/537.36

Operating system:

Logs

Webserver log

``` Insert your webserver log here ```

Nextcloud log

{"reqId":"bdX2KG28DwqRiBf6PrT0","level":3,"time":"2018-08-08T19:30:01+01:00","remoteAddr":"","user":"--","app":"PHP","method":"--","url":"--","message":"Cannot modify header information - headers already sent by (output started at \/var\/www\/nextcloud\/config\/imapauth.config.php:13) at \/var\/www\/nextcloud\/lib\/private\/legacy\/response.php#271","userAgent":"--","version":"13.0.5.2"} {"reqId":"bdX2KG28DwqRiBf6PrT0","level":3,"time":"2018-08-08T19:30:01+01:00","remoteAddr":"","user":"--","app":"PHP","method":"--","url":"--","message":"Cannot modify header information - headers already sent by (output started at \/var\/www\/nextcloud\/config\/imapauth.config.php:13) at \/var\/www\/nextcloud\/lib\/base.php#520","userAgent":"--","version":"13.0.5.2"} {"reqId":"bdX2KG28DwqRiBf6PrT0","level":3,"time":"2018-08-08T19:30:01+01:00","remoteAddr":"","user":"--","app":"PHP","method":"--","url":"--","message":"Cannot modify header information - headers already sent by (output started at \/var\/www\/nextcloud\/config\/imapauth.config.php:13) at \/var\/www\/nextcloud\/lib\/base.php#520","userAgent":"--","version":"13.0.5.2"} {"reqId":"bdX2KG28DwqRiBf6PrT0","level":3,"time":"2018-08-08T19:30:02+01:00","remoteAddr":"","user":"--","app":"PHP","method":"--","url":"--","message":"Cannot modify header information - headers already sent by (output started at \/var\/www\/nextcloud\/config\/imapauth.config.php:13) at \/var\/www\/nextcloud\/lib\/private\/Session\/CryptoWrapper.php#89","userAgent":"--","version":"13.0.5.2"}

Browser log

nextcloud / apps