Login with only kerberos as idp (environment variable) seems broken

首先复现 user_saml 5.0.3 所描述的环境变量 IdP 流程，然后阅读 lib/base.php、lib/private/User/Session.php 和 lib/private/Authentication/Token/ 中引用的身份验证路径。完成的标准是：在 Kerberos 登录期间使用 REMOTE_USER，并且请求不再以空错误页面或令牌失败结束。

Steps to reproduce

1. Install Nextcloud
2. Install user_saml and chose environment variable
3. try to enter REOTE_USER

Expected behaviour

Tell us what should happen
It should take the variable and use it to enable login against kerberos

Actual behaviour

Tell us what happens instead
kerberos authorizes the login, user_saml seems to not catch the value of REMOTE_USER and prints an empty Error page (Nextcloud Errorpage but only Error as Error message
In the error log i can see that kerberos grants the login and in the nextcloudlog i get an error when Nextcloud tries to get the token

Server configuration

Operating system: Ubuntu 20.04

Web server: Apach2

Database: mysql

PHP version: 7.4-cgi

Nextcloud version: (see Nextcloud admin page) 24.x

Where did you install Nextcloud from:
webinstaller

List of activated apps:

  - bbb: 2.4.0
  - cloud_federation_api: 1.7.0
  - dav: 1.22.0
  - federatedfilesharing: 1.14.0
  - files: 1.19.0
  - files_rightclick: 1.3.0
  - files_versions: 1.17.0
  - group_default_quota: 0.1.4
  - lookup_server_connector: 1.12.0
  - nextcloud_announcements: 1.13.0
  - notifications: 2.12.1
  - oauth2: 1.12.0
  - password_policy: 1.14.0
  - privacy: 1.8.0
  - provisioning_api: 1.14.0
  - serverinfo: 1.14.0
  - settings: 1.6.0
  - sharebymail: 1.14.0
  - survey_client: 1.12.0
  - theming: 1.15.0
  - twofactor_backupcodes: 1.13.0
  - updatenotification: 1.14.0
  - user_saml: 5.0.3
  - viewer: 1.8.0
  - workflowengine: 2.6.0

Nextcloud configuration:

[owncloud][PHP][3] {"Exception":"Error","Message":"Array to string conversion at /var/www/nextcloud/lib/private/Log/Errorlog.php#46","Code":0,"Trace":[{"file":"/var/www/nextcloud/lib/private/Log/Errorlog.php","line":46,"function":"onError","class":"OC\\Log\\ErrorHandler","type":"::"},{"file":"/var/www/nextcloud/lib/private/Log.php","line":375,"function":"write","class":"OC\\Log\\Errorlog","type":"->"},{"file":"/var/www/nextcloud/lib/private/Log.php","line":215,"function":"writeLog","class":"OC\\Log","type":"->"},{"file":"/var/www/nextcloud/lib/private/Log.php","line":193,"function":"log","class":"OC\\Log","type":"->"},{"file":"/var/www/nextcloud/lib/private/legacy/OC_App.php","line":183,"function":"debug","class":"OC\\Log","type":"->"},{"file":"/var/www/nextcloud/lib/private/legacy/OC_App.php","line":140,"function":"loadApp","class":"OC_App","type":"::"},{"file":"/var/www/nextcloud/lib/private/Console/Application.php","line":119,"function":"loadApps","class":"OC_App","type":"::"},{"file":"/var/www/nextcloud/console.php","line":99,"function":"loadCommands","class":"OC\\Console\\Application","type":"->"},{"file":"/var/www/nextcloud/occ","line":11,"args":["/var/www/nextcloud/console.php"],"function":"require_once"}],"File":"/var/www/nextcloud/lib/private/Log/ErrorHandler.php","Line":92,"CustomMessage":"--"}
[owncloud][user_saml][0] Array

{
    "system": {
        "instanceid": "***REMOVED SENSITIVE VALUE***",
        "passwordsalt": "***REMOVED SENSITIVE VALUE***",
        "secret": "***REMOVED SENSITIVE VALUE***",
        "trusted_domains": [
            "cloud.domain.tld",
            "cloud",
            "***REMOVED SENSITIVE VALUE***"
        ],
        "default_phone_region": "DE",
        "datadirectory": "***REMOVED SENSITIVE VALUE***",
        "dbtype": "mysql",
        "version": "24.0.7.1",
        "overwrite.cli.url": "https:\/\/cloud.domain.tld",
        "dbname": "***REMOVED SENSITIVE VALUE***",
        "dbhost": "***REMOVED SENSITIVE VALUE***",
        "dbport": "",
        "dbtableprefix": "oc_",
        "mysql.utf8mb4": true,
        "dbuser": "***REMOVED SENSITIVE VALUE***",
        "dbpassword": "***REMOVED SENSITIVE VALUE***",
        "installed": true,
        "memcache.local": "\\OC\\Memcache\\APCu",
        "filelocking.enabled": true,
        "memcache.locking": "\\OC\\Memcache\\Redis",
        "memcache.distributed": "\\OC\\Memcache\\Redis",
        "redis": {
            "host": "***REMOVED SENSITIVE VALUE***",
            "port": 0,
            "timeout": 0
        },
        "maintenance": false,
        "mail_smtpmode": "smtp",
        "mail_smtpauthtype": "LOGIN",
        "mail_sendmailmode": "smtp",
        "mail_smtpauth": 1,
        "mail_smtphost": "***REMOVED SENSITIVE VALUE***",
        "mail_smtpport": "587",
        "mail_smtpsecure": "tls",
        "mail_from_address": "***REMOVED SENSITIVE VALUE***",
        "mail_domain": "***REMOVED SENSITIVE VALUE***",
        "mail_smtpname": "***REMOVED SENSITIVE VALUE***",
        "mail_smtppassword": "***REMOVED SENSITIVE VALUE***",
        "theme": "",
        "loglevel": 0,
        "log_type": "errorlog",
        "app_install_overwrite": [
            "user_saml"
        ],
        "updater.secret": "***REMOVED SENSITIVE VALUE***"
    }
}

Client configuration

Browser:
Chrome mobile on android
Firefox on Ubuntu 22.04
Operating system:

Logs

Nextcloud log (data/owncloud.log)

Insert your Nextcloud log here

[Thu Nov 17 07:48:05.351829 2022] [php7:notice] [pid 637249] [client **********:43448] [owncloud][user_saml][0] Array
[Thu Nov 17 07:48:05.364705 2022] [php7:notice] [pid 637249] [client **********:43448] [owncloud][no app in context][0] {"Exception":"OC\\\\Authentication\\\\Exceptions\\\\InvalidTokenException","Message":"Token does not exist: token does not exist","Code":0,"Trace":[{"file":"/var/www/nextcloud/lib/private/Authentication/Token/Manager.php","line":133,"function":"getToken","class":"OC\\\\Authentication\\\\Token\\\\PublicKeyTokenProvider","type":"->","args":["*** sensitive parameters replaced ***"]},{"file":"/var/www/nextcloud/lib/private/User/Session.php","line":523,"function":"getToken","class":"OC\\\\Authentication\\\\Token\\\\Manager","type":"->","args":["*** sensitive parameters replaced ***"]},{"file":"/var/www/nextcloud/lib/private/User/Session.php","line":436,"function":"isTokenPassword","class":"OC\\\\User\\\\Session","type":"->","args":["*** sensitive parameters replaced ***"]},{"file":"/var/www/nextcloud/lib/private/User/Session.php","line":575,"function":"logClientIn","class":"OC\\\\User\\\\Session","type":"->","args":["*** sensitive parameters replaced ***"]},{"file":"/var/www/nextcloud/lib/base.php","line":1081,"function":"tryBasicAuthLogin","class":"OC\\\\User\\\\Session","type":"->"},{"file":"/var/www/nextcloud/lib/base.php","line":1019,"function":"handleLogin","class":"OC","type":"::"},{"file":"/var/www/nextcloud/index.php","line":36,"function":"handleRequest","class":"OC","type":"::"}],"File":"/var/www/nextcloud/lib/private/Authentication/Token/PublicKeyTokenProvider.php","Line":115,"Previous":{"Exception":"OCP\\\\AppFramework\\\\Db\\\\DoesNotExistException","Message":"token does not exist","Code":0,"Trace":[{"file":"/var/www/nextcloud/lib/private/Authentication/Token/PublicKeyTokenProvider.php","line":111,"function":"getToken","class":"OC\\\\Authentication\\\\Token\\\\PublicKeyTokenMapper","type":"->","args":["*** sensitive parameters replaced ***"]},{"file":"/var/www/nextcloud/lib/private/Authentication/Token/Manager.php","line":133,"function":"getToken","class":"OC\\\\Authentication\\\\Token\\\\PublicKeyTokenProvider","type":"->","args":["*** sensitive parameters replaced ***"]},{"file":"/var/www/nextcloud/lib/private/User/Session.php","line":523,"function":"getToken","class":"OC\\\\Authentication\\\\Token\\\\Manager","type":"->","args":["*** sensitive parameters replaced ***"]},{"file":"/var/www/nextcloud/lib/private/User/Session.php","line":436,"function":"isTokenPassword","class":"OC\\\\User\\\\Session","type":"->","args":["*** sensitive parameters replaced ***"]},{"file":"/var/www/nextcloud/lib/private/User/Session.php","line":575,"function":"logClientIn","class":"OC\\\\User\\\\Session","type":"->","args":["*** sensitive parameters replaced ***"]},{"file":"/var/www/nextcloud/lib/base.php","line":1081,"function":"tryBasicAuthLogin","class":"OC\\\\User\\\\Session","type":"->"},{"file":"/var/www/nextcloud/lib/base.php","line":1019,"function":"handleLogin","class":"OC","type":"::"},{"file":"/var/www/nextcloud/index.php","line":36,"function":"handleRequest","class":"OC","type":"::"}],"File":"/var/www/nextcloud/lib/private/Authentication/Token/PublicKeyTokenMapper.php","Line":89},"message":"Token is not valid: Token does not exist: token does not exist","exception":{},"CustomMessage":"Token is not valid: Token does not exist: token does not exist"}

Browser log

Insert your browser log here, this could for example include:

a) The javascript console log
b) The network log
c) ...