user_saml ignores HTTP-POST signon binding, always uses HTTP-Redirect

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---

### Steps to reproduce
1. Configure `user_saml` to explicitly use `HTTP-POST` for SSO by running:
occ config:app:set user_saml saml_saml20_signon_binding --value="urn:oasis:names:tc:SAML:2.0:bindings:HTTP-POST"
occ config:app:set user_saml saml_force_post --value="1"

2. Confirm config:
`occ config:list user_saml`

```
{
    "apps": {
        "user_saml": {
            "enabled": "yes",
            "general-allow_multiple_user_back_ends": "1",
            "installed_version": "6.6.0",
            "localGroupsCheckForMigration": "{\"dropAfter\":1725503566,\"groups\":{\"1\":\"test\\u7ec4\"}}",
            "saml_force_post": "1",
            "saml_saml20_logout_binding": "urn:oasis:names:tc:SAML:2.0:bindings:HTTP-POST",
            "saml_saml20_signon_binding": "urn:oasis:names:tc:SAML:2.0:bindings:HTTP-POST",
            "type": "saml",
            "types": "authentication"
        }
    }
}
```

3. Run curl to test login:
curl -v -L "https://cloud.example.com/index.php/apps/user_saml/saml/login"


### Expected behaviour
The `user_saml` app should initiate SSO by sending a `HTTP-POST` form to the IdP (as configured).

### Actual behaviour
It still uses a HTTP `303 See Other` redirect with a GET URL (HTTP-Redirect binding), ignoring the `saml_saml20_signon_binding` and `saml_force_post` settings.

### Server configuration

**Web server:** nginx 1.24

**Database:** MySQL 8.0

**PHP version:** 8.2.28

**Nextcloud version:** 30.0.10.1

<details>
<summary>List of activated apps</summary>


`occ app:list`

```
Enabled:
  - activity: 3.0.0
  - admin_audit: 1.20.0
  - announcementcenter: 7.1.1
  - app_api: 4.0.6
  - bruteforcesettings: 3.0.0
  - calendar: 5.2.2
  - checksum: 1.2.6
  - cloud_federation_api: 1.13.0
  - comments: 1.20.1
  - contacts: 7.0.6
  - contactsinteraction: 1.11.0
  - dav: 1.31.1
  - drawio: 3.0.9
  - external: 5.5.2
  - federatedfilesharing: 1.20.0
  - federation: 1.20.0
  - files: 2.2.0
  - files_accesscontrol: 1.20.1
  - files_automatedtagging: 1.20.0
  - files_downloadlimit: 3.0.0
  - files_fulltextsearch: 31.0.0
  - files_mindmap: 0.0.33
  - files_pdfviewer: 3.0.0
  - files_reminders: 1.3.0
  - files_retention: 1.19.1
  - files_sharing: 1.22.0
  - files_trashbin: 1.20.1
  - files_versions: 1.23.0
  - firstrunwizard: 3.0.0
  - fulltextsearch: 30.0.1
  - fulltextsearch_elasticsearch: 30.0.1
  - group_everyone: 0.1.17
  - groupfolders: 18.1.2
  - impersonate: 1.17.1
  - logreader: 3.0.0
  - lookup_server_connector: 1.18.0
  - nextcloud_announcements: 2.0.0
  - notifications: 3.0.0
  - oauth2: 1.18.1
  - onlyoffice: 9.8.0
  - password_policy: 2.0.0
  - passwords: 2025.4.10
  - privacy: 2.0.0
  - provisioning_api: 1.20.0
  - quota_warning: 1.21.0
  - related_resources: 1.5.0
  - serverinfo: 2.0.0
  - settings: 1.13.0
  - sharebymail: 1.20.0
  - support: 2.0.0
  - survey_client: 2.0.0
  - systemtags: 1.20.0
  - tasks: 0.16.1
  - text: 4.1.0
  - theming: 2.6.0
  - twofactor_backupcodes: 1.19.0
  - twofactor_totp: 12.0.0-dev
  - updatenotification: 1.20.0
  - user_saml: 6.6.0
  - user_status: 1.10.0
  - viewer: 3.0.0
  - webhook_listeners: 1.1.0-dev
  - workflowengine: 2.12.0
```

</details>

<details>
<summary>Nextcloud configuration</summary>

`occ config:list`

```
{
    "system": {
        "instanceid": "***REMOVED SENSITIVE VALUE***",
        "passwordsalt": "***REMOVED SENSITIVE VALUE***",
        "secret": "***REMOVED SENSITIVE VALUE***",
        "trusted_domains": [
            "cloud.example.com"
        ],
        "datadirectory": "***REMOVED SENSITIVE VALUE***",
        "dbtype": "mysql",
        "version": "30.0.10.1",
        "overwrite.cli.url": "https:\/\/cloud.example.com",
        "dbname": "***REMOVED SENSITIVE VALUE***",
        "dbhost": "***REMOVED SENSITIVE VALUE***",
        "dbport": "",
        "dbtableprefix": "oc_",
        "mysql.utf8mb4": true,
        "dbuser": "***REMOVED SENSITIVE VALUE***",
        "dbpassword": "***REMOVED SENSITIVE VALUE***",
        "installed": true,
        "default_language": "zh_CN",
        "memcache.local": "\\OC\\Memcache\\Redis",
        "memcache.distributed": "\\OC\\Memcache\\Memcached",
        "memcached_servers": [
            [
                "localhost",
                11211
            ]
        ],
        "maintenance": false,
        "filelocking.enabled": true,
        "memcache.locking": "\\OC\\Memcache\\Redis",
        "redis": {
            "host": "***REMOVED SENSITIVE VALUE***",
            "port": 6379
        },
        "mail_smtpmode": "smtp",
        "mail_sendmailmode": "smtp",
        "mail_from_address": "***REMOVED SENSITIVE VALUE***",
        "mail_domain": "***REMOVED SENSITIVE VALUE***",
        "mail_smtphost": "***REMOVED SENSITIVE VALUE***",
        "mail_smtpport": "25",
        "twofactor_enforced": "true",
        "twofactor_enforced_groups": [],
        "twofactor_enforced_excluded_groups": [],
        "mail_smtpauthtype": "LOGIN",
        "mail_smtpauth": 1,
        "mail_smtpname": "***REMOVED SENSITIVE VALUE***",
        "mail_smtppassword": "***REMOVED SENSITIVE VALUE***",
        "theme": "",
        "loglevel": 2,
        "updater.release.channel": "stable",
        "allow_local_remote_servers": true,
        "trashbin_retention_obligation": "auto,7",
        "ldapIgnoreNamingRules": false,
        "activity_use_cached_mountpoints": "true",
        "enabledPreviewProviders": [
            "OC\\Preview\\PNG",
            "OC\\Preview\\JPEG",
            "OC\\Preview\\GIF",
            "OC\\Preview\\HEIC",
            "OC\\Preview\\BMP",
            "OC\\Preview\\XBitmap",
            "OC\\Preview\\Movie",
            "OC\\Preview\\MKV",
            "OC\\Preview\\MP4",
            "OC\\Preview\\AVI",
            "OC\\Preview\\TXT"
        ],
        "proxy": "porxy.example.com",
        "app_install_overwrite": [
            "files_texteditor",
            "files_trackdownloads"
        ],
        "default_phone_region": "CN",
        "maintenance_window_start": 1,
        "defaultapp": "",
        "debug": true
    },
    "apps": {
        "activity": {
            "enable_email": "no",
            "enabled": "yes",
            "installed_version": "3.0.0",
            "types": "filesystem"
        },
        "admin_audit": {
            "enabled": "yes",
            "installed_version": "1.20.0",
            "types": "logging"
        },
        "announcementcenter": {
            "enabled": "yes",
            "installed_version": "7.1.1",
            "types": "logging"
        },
        "app_api": {
            "enabled": "yes",
            "installed_version": "4.0.6",
            "types": ""
        },
        "backgroundjob": {
            "lastjob": "3395"
        },
        "bruteforcesettings": {
            "enabled": "yes",
            "installed_version": "3.0.0",
            "types": ""
        },
        "calendar": {
            "enabled": "yes",
            "installed_version": "5.2.2",
            "types": ""
        },
        "checksum": {
            "enabled": "yes",
            "installed_version": "1.2.6",
            "types": "filesystem"
        },
        "circles": {
            "enabled": "no",
            "installed_version": "24.0.1",
            "loopback_tmp_scheme": "https",
            "maintenance_run": "0",
            "maintenance_update": "{\"maximum\":3,\"3\":1662126124,\"2\":1662126963,\"1\":1662127203}",
            "migration_22": "1",
            "migration_run": "0",
            "types": "filesystem,dav"
        },
        "cloud_federation_api": {
            "enabled": "yes",
            "installed_version": "1.13.0",
            "types": "filesystem"
        },
        "comments": {
            "enabled": "yes",
            "installed_version": "1.20.1",
            "types": "logging"
        },
        "contacts": {
            "enabled": "yes",
            "installed_version": "7.0.6",
            "types": "dav"
        },
        "contactsinteraction": {
            "enabled": "yes",
            "installed_version": "1.11.0",
            "types": "dav"
        },
        "core": {
            "backgroundjobs_mode": "cron",
            "enterpriseLogoChecked": "yes",
            "files_metadata_installed": "1",
            "installed.bundles": "[\"CoreBundle\"]",
            "installedat": "1585822201.5797",
            "lastcron": 1752414782,
            "lastupdateResult": "{\"version\":\"30.0.13.1\",\"versionstring\":\"Nextcloud 30.0.13\",\"url\":\"https:\\\/\\\/download.nextcloud.com\\\/server\\\/releases\\\/nextcloud-30.0.13.zip\",\"web\":\"https:\\\/\\\/docs.nextcloud.com\\\/server\\\/30\\\/admin_manual\\\/maintenance\\\/upgrade.html\",\"changes\":\"https:\\\/\\\/updates.nextcloud.com\\\/changelog_server\\\/?version=30.0.13\",\"autoupdater\":\"1\",\"eol\":\"0\"}",
            "lastupdatedat": 1752368462,
            "metadataGenerationDone": "true",
            "moveavatarsdone": "yes",
            "previewsCleanedUp": "1",
            "public_files": "files_sharing\/public.php",
            "public_webdav": "dav\/appinfo\/v1\/publicwebdav.php",
            "shareapi_allow_links": "yes",
            "shareapi_allow_resharing": "no",
            "shareapi_default_expire_date": "yes",
            "shareapi_default_internal_expire_date": "yes",
            "shareapi_default_permission_cancreate": "no",
            "shareapi_default_permission_canshare": "no",
            "shareapi_default_permission_canupdate": "no",
            "shareapi_default_permissions": "1",
            "shareapi_enable_link_password_by_default": "yes",
            "shareapi_enforce_links_password": "no",
            "shareapi_exclude_groups": "no",
            "shareapi_exclude_groups_list": "[\"\"]",
            "shareapi_restrict_user_enumeration_to_group": "yes",
            "shareapi_restrict_user_enumeration_to_phone": "yes",
            "theming.variables": "b678bdb23653e1e0b8dafc5f181edd91",
            "updater.secret.created": 1743250974,
            "vendor": "nextcloud",
            "files_metadata": {
                "blurhash": {
                    "value": null,
                    "type": "string",
                    "etag": "c68c68be2c207ebe8c78a82c299de015",
                    "indexed": false,
                    "editPermission": 0
                }
            },
            "oc.integritycheck.checker": []
        },
        "dashboard": {
            "enabled": "no",
            "installed_version": "7.0.0",
            "types": ""
        },
        "dav": {
            "buildCalendarReminderIndex": "yes",
            "buildCalendarSearchIndex": "yes",
            "builtSocialSearchIndex": "yes",
            "chunks_migrated": "1",
            "enabled": "yes",
            "installed_version": "1.31.1",
            "needs_system_address_book_sync": "no",
            "regeneratedBirthdayCalendarsForYearFix": "yes",
            "types": "filesystem"
        },
        "deck": {
            "enabled": "no",
            "installed_version": "1.14.4",
            "types": "dav"
        },
        "documentserver_community": {
            "enabled": "no",
            "installed_version": "0.1.12",
            "types": "filesystem"
        },
        "drawio": {
            "DrawioAutosave": "yes",
            "DrawioLang": "zh",
            "DrawioOffline": "no",
            "DrawioTheme": "kennedy",
            "DrawioUrl": "https:\/\/drawio.example.com",
            "enabled": "yes",
            "installed_version": "3.0.9",
            "types": "filesystem"
        },
        "emlviewer": {
            "enabled": "no",
            "installed_version": "1.0.11",
            "types": ""
        },
        "external": {
            "enabled": "yes",
            "installed_version": "5.5.2",
            "jwt_token_privkey_es256": "***REMOVED SENSITIVE VALUE***",
            "jwt_token_pubkey_es256": "-----BEGIN PUBLIC KEY-----\nMFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAEOeVM1+O9necqL3TktHLUE+RZ\/jPV\nUSyZA+b5MHcSkuSRSqTuQsYYJS8CHnek1uAruQBCtxdvaKR3QLZa73SBwQ==\n-----END PUBLIC KEY-----\n",
            "types": ""
        },
        "extract": {
            "enabled": "no",
            "installed_version": "1.3.6",
            "types": ""
        },
        "federatedfilesharing": {
            "enabled": "yes",
            "installed_version": "1.20.0",
            "types": ""
        },
        "federation": {
            "enabled": "yes",
            "installed_version": "1.20.0",
            "types": "authentication"
        },
        "files": {
            "cronjob_scan_files": "500",
            "default_quota": "10 GB",
            "enabled": "yes",
            "installed_version": "2.2.0",
            "mimetype_version": "30.0.8.1",
            "types": "filesystem",
            "watermark_allGroups": "no",
            "watermark_allGroupsList": "",
            "watermark_allTags": "no",
            "watermark_allTagsList": "",
            "watermark_enabled": "yes",
            "watermark_linkAll": "yes",
            "watermark_linkRead": "no",
            "watermark_linkSecure": "no",
            "watermark_linkTags": "no",
            "watermark_linkTagsList": "",
            "watermark_shareAll": "yes",
            "watermark_shareRead": "no",
            "watermark_text": "{userId}"
        },
        "files_accesscontrol": {
            "enabled": "yes",
            "installed_version": "1.20.1",
            "types": "filesystem"
        },
        "files_automatedtagging": {
            "enabled": "yes",
            "installed_version": "1.20.0",
            "types": "filesystem"
        },
        "files_downloadactivity": {
            "enabled": "no",
            "installed_version": "1.18.1",
            "types": "filesystem"
        },
        "files_downloadlimit": {
            "enabled": "yes",
            "installed_version": "3.0.0",
            "types": ""
        },
        "files_fulltextsearch": {
            "enabled": "yes",
            "files_audio": "0",
            "files_encrypted": "0",
            "files_external": "0",
            "files_federated": "0",
            "files_group_folders": "1",
            "files_image": "0",
            "files_local": "1",
            "files_office": "1",
            "files_pdf": "1",
            "files_size": "20",
            "installed_version": "31.0.0",
            "types": "filesystem"
        },
        "files_mindmap": {
            "enabled": "yes",
            "installed_version": "0.0.33",
            "types": ""
        },
        "files_pdfviewer": {
            "enabled": "yes",
            "installed_version": "3.0.0",
            "types": ""
        },
        "files_reminders": {
            "enabled": "yes",
            "installed_version": "1.3.0",
            "types": ""
        },
        "files_retention": {
            "enabled": "yes",
            "installed_version": "1.19.1",
            "types": ""
        },
        "files_rightclick": {
            "enabled": "no",
            "installed_version": "1.6.0",
            "types": ""
        },
        "files_sharing": {
            "enabled": "yes",
            "installed_version": "1.22.0",
            "lookupServerUploadEnabled": "no",
            "types": "filesystem"
        },
        "files_texteditor": {
            "enabled": "no",
            "installed_version": "2.15.1",
            "types": ""
        },
        "files_trackdownloads": {
            "enabled": "no",
            "installed_version": "1.11.0",
            "types": "filesystem"
        },
        "files_trashbin": {
            "background_job_expire_trash_offset": 0,
            "enabled": "yes",
            "installed_version": "1.20.1",
            "types": "filesystem,dav"
        },
        "files_versions": {
            "enabled": "yes",
            "installed_version": "1.23.0",
            "types": "filesystem,dav"
        },
        "firstrunwizard": {
            "enabled": "yes",
            "installed_version": "3.0.0",
            "types": "logging"
        },
        "flowupload": {
            "enabled": "no",
            "installed_version": "1.1.3",
            "types": ""
        },
        "fulltextsearch": {
            "app_navigation": "1",
            "cron_err_reset": "1751850422",
            "enabled": "yes",
            "installed_version": "30.0.1",
            "migration_24": "1",
            "provider_indexed": "{\"files\":\"1\"}",
            "search_platform": "OCA\\FullTextSearch_Elasticsearch\\Platform\\ElasticSearchPlatform",
            "types": ""
        },
        "fulltextsearch_elasticsearch": {
            "analyzer_tokenizer": "standard",
            "elastic_host": "http:\/\/127.0.0.1:9200",
            "elastic_index": "nextcloud_fulltext_index",
            "enabled": "yes",
            "installed_version": "30.0.1",
            "types": ""
        },
        "group_everyone": {
            "enabled": "yes",
            "installed_version": "0.1.17",
            "types": "authentication"
        },
        "groupfolders": {
            "cron_last_folder_index": "1",
            "enabled": "yes",
            "installed_version": "18.1.2",
            "types": "filesystem,dav"
        },
        "impersonate": {
            "enabled": "yes",
            "installed_version": "1.17.1",
            "types": "prevent_group_restriction"
        },
        "integration_jira": {
            "enabled": "no",
            "installed_version": "1.3.0",
            "types": ""
        },
        "ldap_write_support": {
            "enabled": "no",
            "installed_version": "1.12.1",
            "types": ""
        },
        "logreader": {
            "enabled": "yes",
            "installed_version": "3.0.0",
            "types": "logging"
        },
        "lookup_server_connector": {
            "enabled": "yes",
            "installed_version": "1.18.0",
            "types": "authentication"
        },
        "mail": {
            "enabled": "no",
            "installed_version": "1.9.5",
            "types": ""
        },
        "nextcloud_announcements": {
            "enabled": "yes",
            "installed_version": "2.0.0",
            "notification_groups": "[\"admin\"]",
            "pub_date": "Thu, 24 Oct 2019 00:00:00 +0200",
            "types": "logging"
        },
        "notes": {
            "enabled": "no",
            "installed_version": "4.12.0",
            "types": ""
        },
        "notifications": {
            "enabled": "yes",
            "installed_version": "3.0.0",
            "types": "logging"
        },
        "oauth2": {
            "enabled": "yes",
            "installed_version": "1.18.1",
            "types": "authentication"
        },
        "ocdownloader": {
            "enabled": "no",
            "installed_version": "1.8.1",
            "types": ""
        },
        "onlyoffice": {
            "DocumentServerInternalUrl": "",
            "DocumentServerUrl": "https:\/\/office.example.com\/",
            "StorageUrl": "",
            "advanced": "false",
            "customizationChat": "true",
            "customizationCompactHeader": "true",
            "customizationFeedback": "true",
            "customizationForcesave": "false",
            "customizationHelp": "true",
            "customizationReviewDisplay": "original",
            "customizationTheme": "theme-classic-light",
            "customizationToolbarNoTabs": "true",
            "defFormats": "{\"csv\":\"true\",\"doc\":\"true\",\"docm\":\"false\",\"docx\":\"true\",\"docxf\":\"true\",\"oform\":\"true\",\"dotx\":\"false\",\"epub\":\"false\",\"html\":\"false\",\"odp\":\"false\",\"ods\":\"false\",\"odt\":\"false\",\"otp\":\"false\",\"ots\":\"false\",\"ott\":\"false\",\"pdf\":\"false\",\"potm\":\"false\",\"potx\":\"false\",\"ppsm\":\"false\",\"ppsx\":\"false\",\"ppt\":\"true\",\"pptm\":\"false\",\"pptx\":\"true\",\"rtf\":\"false\",\"txt\":\"false\",\"xls\":\"true\",\"xlsm\":\"false\",\"xlsx\":\"true\",\"xltm\":\"false\",\"xltx\":\"false\"}",
            "demo": "{\"available\":false,\"enabled\":false,\"start\":{\"date\":\"2021-09-10 03:35:08.551139\",\"timezone_type\":3,\"timezone\":\"UTC\"}}",
            "editFormats": "{\"csv\":\"true\",\"odp\":\"false\",\"ods\":\"false\",\"odt\":\"false\",\"rtf\":\"false\",\"txt\":\"false\"}",
            "enabled": "yes",
            "groups": "[]",
            "installed_version": "9.8.0",
            "jwt_header": "",
            "jwt_secret": "***REMOVED SENSITIVE VALUE***",
            "preview": "false",
            "sameTab": "false",
            "settings_error": "Server error: `GET https:\/\/office.example.com\/healthcheck` resulted in a `502 Bad Gateway` response:\n<html>\r\n<head><title>502 Bad Gateway<\/title><\/head>\r\n<body>\r\n<center><h1>502 Bad Gateway<\/h1><\/center>\r\n<hr><center>ngin (truncated...)\n",
            "types": "prevent_group_restriction",
            "verify_peer_off": "false",
            "versionHistory": "true"
        },
        "passman": {
            "enabled": "no",
            "installed_version": "2.4.12",
            "types": ""
        },
        "password_policy": {
            "enabled": "yes",
            "enforceNumericCharacters": "1",
            "enforceSpecialCharacters": "1",
            "enforceUpperLowerCase": "1",
            "installed_version": "2.0.0",
            "types": "authentication"
        },
        "passwords": {
            "SSEv1ServerKey": "***REMOVED SENSITIVE VALUE***",
            "cron\/php\/version\/id": "80228",
            "cron\/php\/version\/string": "8.2.28",
            "enabled": "yes",
            "installed_version": "2025.4.10",
            "migration\/customFields": "2020.12.2",
            "passwords\/localdb\/type": "hibp",
            "types": "",
            "web\/php\/version\/id": "80129",
            "web\/php\/version\/string": "8.1.29"
        },
        "photos": {
            "enabled": "no",
            "installed_version": "1.2.3",
            "types": ""
        },
        "privacy": {
            "enabled": "yes",
            "installed_version": "2.0.0",
            "types": ""
        },
        "provisioning_api": {
            "enabled": "yes",
            "installed_version": "1.20.0",
            "types": "prevent_group_restriction"
        },
        "quicknotes": {
            "enabled": "no",
            "installed_version": "0.8.30",
            "types": ""
        },
        "quota_warning": {
            "enabled": "yes",
            "installed_version": "1.21.0",
            "types": "filesystem"
        },
        "recommendations": {
            "enabled": "no",
            "installed_version": "0.6.0",
            "types": ""
        },
        "related_resources": {
            "enabled": "yes",
            "installed_version": "1.5.0",
            "types": ""
        },
        "riotchat": {
            "enabled": "no",
            "installed_version": "0.18.8",
            "types": ""
        },
        "serverinfo": {
            "cached_count_filecache": "773",
            "cached_count_storages": "6",
            "enabled": "yes",
            "installed_version": "2.0.0",
            "types": ""
        },
        "settings": {
            "appstore-fetcher-lastFailure": "1752368524",
            "enabled": "yes",
            "installed_version": "1.13.0",
            "types": ""
        },
        "sharebymail": {
            "enabled": "yes",
            "installed_version": "1.20.0",
            "types": "filesystem"
        },
        "spreed": {
            "enabled": "no",
            "installed_version": "20.1.6",
            "project_access_invalidated": "1",
            "signaling_token_privkey_es256": "***REMOVED SENSITIVE VALUE***",
            "signaling_token_pubkey_es256": "***REMOVED SENSITIVE VALUE***",
            "stun_servers": "***REMOVED SENSITIVE VALUE***",
            "types": "dav,prevent_group_restriction"
        },
        "support": {
            "SwitchUpdaterServerHasRun": "yes",
            "enabled": "yes",
            "installed_version": "2.0.0",
            "types": "session"
        },
        "survey_client": {
            "enabled": "yes",
            "installed_version": "2.0.0",
            "types": ""
        },
        "systemtags": {
            "enabled": "yes",
            "installed_version": "1.20.0",
            "types": "logging"
        },
        "tasks": {
            "enabled": "yes",
            "installed_version": "0.16.1",
            "types": ""
        },
        "text": {
            "enabled": "yes",
            "installed_version": "4.1.0",
            "types": "dav"
        },
        "theming": {
            "backgroundMime": "image\/png",
            "background_color": "#D70D0D",
            "cachebuster": "35",
            "enabled": "yes",
            "installed_version": "2.6.0",
            "logoDimensions": "308x322",
            "logoMime": "image\/png",
            "logoheaderMime": "image\/png",
            "name": "\u6d4b\u8bd5\u6613\u4e91\u76d8",
            "primary_color": "#D70D0D",
            "slogan": "***REMOVED SENSITIVE VALUE***",
            "types": "logging",
            "url": "***REMOVED SENSITIVE VALUE***"
        },
        "twofactor_backupcodes": {
            "enabled": "yes",
            "installed_version": "1.19.0",
            "types": ""
        },
        "twofactor_totp": {
            "enabled": "yes",
            "installed_version": "12.0.0-dev",
            "types": ""
        },
        "updatenotification": {
            "announcementcenter": "7.1.3",
            "bruteforcesettings": "2.2.0",
            "calendar": "5.3.5",
            "checksum": "1.2.6",
            "contacts": "7.1.5",
            "core": "30.0.13.1",
            "drawio": "3.0.9",
            "emlviewer": "1.0.7",
            "enabled": "yes",
            "external": "4.0.1",
            "extract": "1.3.6",
            "files_automatedtagging": "1.14.2",
            "files_downloadactivity": "1.16.0",
            "files_mindmap": "0.0.33",
            "files_retention": "1.19.1",
            "files_texteditor": "2.15.1",
            "group_everyone": "0.1.16",
            "groupfolders": "18.1.3",
            "impersonate": "1.11.1",
            "installed_version": "1.20.0",
            "notes": "4.1.1",
            "onlyoffice": "9.9.0",
            "passman": "2.4.4",
            "passwords": "2025.7.10",
            "quota_warning": "1.20.0",
            "spreed": "20.1.6",
            "tasks": "0.16.1",
            "twofactor_totp": "6.4.1",
            "types": "",
            "update_check_errors": 0,
            "user_saml": "6.5.0",
            "workflow_pdf_converter": "1.3.2"
        },
        "user_external": {
            "enabled": "no",
            "installed_version": "0.9.0",
            "types": "prelogin,authentication"
        },
        "user_ldap": {
            "background_sync_interval": "1800",
            "enabled": "no",
            "installed_version": "1.21.0",
            "s01_lastChange": "1631270118",
            "s01has_memberof_filter_support": "0",
            "s01home_folder_naming_rule": "",
            "s01last_jpegPhoto_lookup": "0",
            "s01ldap_agent_password": "***REMOVED SENSITIVE VALUE***",
            "s01ldap_attributes_for_group_search": "",
            "s01ldap_attributes_for_user_search": "",
            "s01ldap_backup_host": "",
            "s01ldap_backup_port": "",
            "s01ldap_base": "",
            "s01ldap_base_groups": "",
            "s01ldap_base_users": "",
            "s01ldap_cache_ttl": "600",
            "s01ldap_configuration_active": "0",
            "s01ldap_default_ppolicy_dn": "",
            "s01ldap_display_name": "displayName",
            "s01ldap_dn": "",
            "s01ldap_dynamic_group_member_url": "",
            "s01ldap_email_attr": "",
            "s01ldap_experienced_admin": "0",
            "s01ldap_expert_username_attr": "",
            "s01ldap_expert_uuid_group_attr": "",
            "s01ldap_expert_uuid_user_attr": "",
            "s01ldap_ext_storage_home_attribute": "",
            "s01ldap_gid_number": "gidNumber",
            "s01ldap_group_display_name": "cn",
            "s01ldap_group_filter": "",
            "s01ldap_group_filter_mode": "0",
            "s01ldap_group_member_assoc_attribute": "",
            "s01ldap_groupfilter_groups": "",
            "s01ldap_groupfilter_objectclass": "",
            "s01ldap_host": "",
            "s01ldap_login_filter": "",
            "s01ldap_login_filter_mode": "0",
            "s01ldap_loginfilter_attributes": "",
            "s01ldap_loginfilter_email": "0",
            "s01ldap_loginfilter_username": "1",
            "s01ldap_matching_rule_in_chain_state": "unknown",
            "s01ldap_nested_groups": "0",
            "s01ldap_override_main_server": "",
            "s01ldap_paging_size": "500",
            "s01ldap_port": "",
            "s01ldap_quota_attr": "",
            "s01ldap_quota_def": "",
            "s01ldap_tls": "0",
            "s01ldap_turn_off_cert_check": "0",
            "s01ldap_turn_on_pwd_change": "0",
            "s01ldap_user_avatar_rule": "default",
            "s01ldap_user_display_name_2": "",
            "s01ldap_user_filter_mode": "0",
            "s01ldap_userfilter_groups": "",
            "s01ldap_userfilter_objectclass": "",
            "s01ldap_userlist_filter": "",
            "s01use_memberof_to_detect_membership": "1",
            "types": "authentication"
        },
        "user_saml": {
            "enabled": "yes",
            "general-allow_multiple_user_back_ends": "1",
            "installed_version": "6.6.0",
            "localGroupsCheckForMigration": "{\"dropAfter\":1725503566,\"groups\":{\"1\":\"test\\u7ec4\"}}",
            "saml_force_post": "1",
            "saml_saml20_logout_binding": "urn:oasis:names:tc:SAML:2.0:bindings:HTTP-POST",
            "saml_saml20_signon_binding": "urn:oasis:names:tc:SAML:2.0:bindings:HTTP-POST",
            "type": "saml",
            "types": "authentication"
        },
        "user_status": {
            "enabled": "yes",
            "installed_version": "1.10.0",
            "types": ""
        },
        "viewer": {
            "enabled": "yes",
            "installed_version": "3.0.0",
            "types": ""
        },
        "w2g2": {
            "enabled": "no",
            "installed_version": "3.3.9",
            "types": ""
        },
        "weather_status": {
            "enabled": "no",
            "installed_version": "1.0.0",
            "types": ""
        },
        "webhook_listeners": {
            "enabled": "yes",
            "installed_version": "1.1.0-dev",
            "types": "filesystem"
        },
        "workflow_pdf_converter": {
            "enabled": "no",
            "installed_version": "1.8.0",
            "types": "filesystem"
        },
        "workflow_script": {
            "enabled": "no",
            "installed_version": "1.15.0",
            "types": "filesystem"
        },
        "workflowengine": {
            "enabled": "yes",
            "installed_version": "2.12.0",
            "types": "filesystem"
        }
    }
}
```

</details>

### Browser

**Browser name:** Chrome  
**Browser version:** 136  
**Operating system:** Windows 10

<details>
<summary>Browser log</summary>

{"data":"...","code":"50000","msg":"Request method 'GET' not supported"}

</details>

<details>
<summary>Additional curl trace (follow redirects)</summary>

`curl -v -L "https://cloud.example.com/index.php/apps/user_saml/saml/login"`

```
...
< HTTP/1.1 303 See Other
< Location: https://tsso.example.com:1443/esc-sso/idp/profile/SAML2/POST/SLO?SAMLRequest=...
...
GET /esc-sso/idp/profile/SAML2/POST/SLO?SAMLRequest=... HTTP/1.1
...
< HTTP/1.1 200 OK
< content-type: application/json;charset=UTF-8
{"data":"...","code":"50000","msg":"Request method 'GET' not supported"}
```

</details>

---

### Additional comments
Even after explicitly setting `saml_saml20_signon_binding` and `saml_force_post` the login process always falls back to a HTTP GET redirect.  
Expected `user_saml` to generate a form POST to IdP instead.

The current SAML Identity Provider (IdP) only supports HTTP-POST bindings for SSO initiation. Therefore user_saml ignoring this setting leads to incompatibility.

Please help clarify if this is a bug or a misconfiguration.

---

Thank you! 🙌

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user_saml ignores HTTP-POST signon binding, always uses HTTP-Redirect #974

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user_saml ignores HTTP-POST signon binding, always uses HTTP-Redirect #974

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