Make Imaginary work with server-side encryption

⚠️ This issue respects the following points: ⚠️

• This is a bug, not a question or a configuration/webserver/proxy issue.
• This issue is not already reported on Github (I've searched it).
• Nextcloud Server is up to date. See Maintenance and Release Schedule for supported versions.
• Nextcloud Server is running on 64bit capable CPU, PHP and OS.
• I agree to follow Nextcloud's Code of Conduct.

Bug description

When using server-side encryption, if you enable the usage of Imaginary micro service, all picture are sent encrypted to imaginary, making the micro service totally useless ( and silently, you can only check that by seeing errors 400 in imaginary log, instead of normal 200 answers)

Steps to reproduce

1. Setup nextcloud with server side encryption
2. Enable Imaginary micro service
3. See that imaginary cannot generate preview

Expected behavior

Previews are correctly generated ( by not using Imaginary with server side encryption, or by having the server unencrypt files before sending them to imaginary)

Installation method

Community Manual installation with Archive

Operating system

RHEL/CentOS

PHP engine version

PHP 8.1

Web server

Apache (supported)

Database engine version

MariaDB

Is this bug present after an update or on a fresh install?

No response

Are you using the Nextcloud Server Encryption module?

Encryption is Enabled

What user-backends are you using?

• Default user-backend (database)
• LDAP/ Active Directory
• SSO - SAML
• Other

Configuration report

{
    "system": {
        "log_type": "syslog",
        "datadirectory": "***REMOVED SENSITIVE VALUE***",
        "updatechecker": false,
        "check_for_working_htaccess": false,
        "asset-pipeline.enabled": false,
        "assetdirectory": "\/var\/lib\/nextcloud",
        "preview_libreoffice_path": "\/usr\/bin\/libreoffice",
        "apps_paths": [
            {
                "path": "\/home\/nextcloud\/www\/nextcloud\/apps",
                "url": "\/apps",
                "writable": false
            },
            {
                "path": "\/home\/nextcloud\/data\/apps",
                "url": "\/apps-appstore",
                "writable": true
            }
        ],
        "instanceid": "***REMOVED SENSITIVE VALUE***",
        "passwordsalt": "***REMOVED SENSITIVE VALUE***",
        "secret": "***REMOVED SENSITIVE VALUE***",
        "trusted_domains": [
            "cloud.offmysoul.me"
        ],
        "dbtype": "mysql",
        "mysql.utf8mb4": true,
        "version": "24.0.5.1",
        "overwrite.cli.url": "https:\/\/cloud.offmysoul.me",
        "installed": true,
        "theme": "",
        "loglevel": 2,
        "maintenance": false,
        "mail_from_address": "***REMOVED SENSITIVE VALUE***",
        "mail_smtpmode": "smtp",
        "mail_sendmailmode": "smtp",
        "mail_domain": "***REMOVED SENSITIVE VALUE***",
        "dbname": "***REMOVED SENSITIVE VALUE***",
        "dbhost": "***REMOVED SENSITIVE VALUE***",
        "dbuser": "***REMOVED SENSITIVE VALUE***",
        "dbpassword": "***REMOVED SENSITIVE VALUE***",
        "memcache.local": "\\OC\\Memcache\\Redis",
        "filelocking.enabled": true,
        "memcache.distributed": "\\OC\\Memcache\\Redis",
        "memcache.locking": "\\OC\\Memcache\\Redis",
        "redis": {
            "host": "***REMOVED SENSITIVE VALUE***",
            "port": 6379,
            "timeout": 1.5,
            "dbindex": 0,
            "password": "***REMOVED SENSITIVE VALUE***"
        },
        "updater.release.channel": "stable",
        "app_install_overwrite": [
            "sharerenamer",
            "files_reader",
            "flowupload"
        ],
        "encryption.legacy_format_support": false,
        "encryption.key_storage_migrated": false,
        "enabledPreviewProviders": [
            "OC\\Preview\\MP3",
            "OC\\Preview\\TXT",
            "OC\\Preview\\MarkDown",
            "OC\\Preview\\OpenDocument",
            "OC\\Preview\\Krita",
            "OC\\Preview\\Imaginary"
        ],
        "preview_imaginary_url": "http:\/\/xxx.xxx.xxx.xxx:9000",
        "preview_max_x": "2048",
        "preview_max_y": "2048",
        "jpeg_quality": "60"
    }
}

List of activated Apps

Enabled:
  - accessibility: 1.10.0
  - activity: 2.16.0
  - admin_audit: 1.14.0
  - analytics: 4.4.0
  - camerarawpreviews: 0.8.0
  - circles: 24.0.1
  - cloud_federation_api: 1.7.0
  - comments: 1.14.0
  - contacts: 4.2.1
  - contactsinteraction: 1.5.0
  - dav: 1.22.0
  - encryption: 2.12.0
  - federatedfilesharing: 1.14.0
  - federation: 1.14.0
  - files: 1.19.0
  - files_antivirus: 3.3.1
  - files_pdfviewer: 2.5.0
  - files_rightclick: 1.3.0
  - files_sharing: 1.16.2
  - files_trashbin: 1.14.0
  - files_versions: 1.17.0
  - files_videoplayer: 1.13.0
  - firstrunwizard: 2.13.0
  - logreader: 2.9.0
  - lookup_server_connector: 1.12.0
  - metadata: 0.16.0
  - notifications: 2.12.1
  - oauth2: 1.12.0
  - password_policy: 1.14.0
  - photos: 1.6.0
  - previewgenerator: 5.1.0
  - privacy: 1.8.0
  - provisioning_api: 1.14.0
  - recommendations: 1.3.0
  - serverinfo: 1.14.0
  - settings: 1.6.0
  - sharebymail: 1.14.0
  - sharerenamer: 3.0.1
  - support: 1.7.0
  - survey_client: 1.12.0
  - systemtags: 1.14.0
  - text: 3.5.1
  - theming: 1.15.0
  - twofactor_backupcodes: 1.13.0
  - updatenotification: 1.14.0
  - user_status: 1.4.0
  - viewer: 1.8.0
  - weather_status: 1.4.0
  - workflowengine: 2.6.0
Disabled:
  - bruteforcesettings: 2.4.0
  - calendar: 3.5.0
  - dashboard: 7.3.0
  - deck: 1.7.1
  - files_accesscontrol: 1.14.1
  - files_external
  - files_reader: 1.5.3
  - files_readmemd: 1.2.2
  - files_texteditor: 2.14.0
  - flowupload: 1.1.3
  - fulltextsearch: 24.0.0
  - gallery: 18.4.0
  - groupfolders: 12.0.1
  - imageconverter: 1.3.2
  - integration_github: 1.0.4
  - integration_twitter: 1.0.3
  - maps: 0.2.1
  - nextcloud_announcements: 1.4.0
  - ojsxc: 5.0.0
  - user_ldap
  - user_pwauth: 2.7.2

Nextcloud Signing status

No errors have been found.

Nextcloud Logs

No response

Additional info

No response

Start by tracing the OC\Preview\Imaginary provider named in enabledPreviewProviders and the server-side encryption file-read path. Reproduce the setup described in the issue, then verify that previews are generated successfully and Imaginary receives usable image data rather than encrypted content.