Sharing backend for principals not found /ldap

[k4tfish]

I cannot share calenders with AD users. While searching for a contact to share, the app doesn't show any users.

The following appears in the log: "Sharing backend for principals not found"

There was a similar issue in the oc calender app. owncloud/core#23827

-- k4tfish - calendar 1.4.0 /NC 10.0.1 / Ubuntu 16.04 / Apache

[nickvergessen]

@blizzz any idea?

[blizzz]

Works for me, although the user ids are shown instead of the display names, when sharing. cc @georgehrke

@k4tfish can you please give a complete bug report using the template? thx

Github returns a 404 on the linked issue.

[georgehrke]

Works for me, although the user ids are shown instead of the display names, when sharing. cc @georgehrke

Yes, working on that

[k4tfish]

@blizzz,
the correct link to the owncloud issue.
owncloud/core#23827

Steps to reproduce

Sharing of a cal or folder using the web ui.

Expected behaviour

Showing the users/groups to select them.

Actual behaviour

It can't find any user usually but worked sometimes. Then the calapp shows the SAMaccount name,
whereas the fileapp shows the display name.

Server configuration

Ubuntu 16.04. Apache/2.4.18, MariaDB 10.0.27. mod-php 7.0.8. Nextcloud 10.0.1
Fresh install from 10.0.1 tarball, no other issues so far.

Login as admin user into your Nextcloud and access 
http://example.com/index.php/settings/integrity/failed 
paste the results here.
No errors have been found.
</details>

**List of activated apps:**
<details>
<summary>App list</summary>

If you have access to your command line run e.g.:
sudo -u www-data php occ app:list
from within your Nextcloud installation folder
Enabled:

• activity: 2.3.2
• apporder: 0.3.2
• bookmarks: 0.9.0
• calendar: 1.4.0
• comments: 1.0.0
• contacts: 1.4.0.0
• dav: 1.0.1
• direct_menu: 0.9.2
• federatedfilesharing: 1.0.1
• federation: 1.0.1
• files: 1.5.2
• files_accesscontrol: 1.1.2
• files_automatedtagging: 1.1.1
• files_external: 1.0.2
• files_pdfviewer: 0.8.1
• files_retention: 1.0.0
• files_sharing: 1.0.0
• files_texteditor: 2.1
• files_trashbin: 1.0.0
• files_versions: 1.3.0
• files_videoplayer: 0.9.8
• firstrunwizard: 1.1
• gallery: 15.0.0
• logreader: 1.1.5
• notifications: 0.3.0
• ownnote: 1.08
• password_policy: 1.0.0
• passwords: 19
• provisioning_api: 1.0.0
• serverinfo: 1.1.1
• survey_client: 0.1.5
• systemtags: 1.0.2
• tasks: 0.9.3
• templateeditor: 0.1
• theming: 1.0.1
• updatenotification: 1.0.1
• user_ldap: 1.0.1
• workflowengine: 1.0.1
  Disabled:
• admin_audit
• encryption
• external
• mail
• user_external
• user_saml

The content of config/config.php:

Config report

{
"system": {
"instanceid": "ockdzcqsvo3v",
"passwordsalt": "_REMOVED SENSITIVE VALUE",
"secret": "_REMOVED SENSITIVE VALUE",
"trusted_domains": [
"nextcloud.dc.local",
"nextcloud.x",
"10.200.125.230"
],
"datadirectory": "/var/ncdata",
"overwrite.cli.url": "/",
"dbtype": "mysql",
"version": "9.1.1.5",
"dbname": "nextcloud",
"dbhost": "localhost",
"dbport": "",
"dbtableprefix": "oc_",
"dbuser": "_REMOVED SENSITIVE VALUE",
"dbpassword": "_REMOVED SENSITIVE VALUE",
"logtimezone": "UTC",
"installed": true,
"ldapIgnoreNamingRules": false,
"ldapProviderFactory": "\OCA\User_LDAP\LDAPProviderFactory",
"appstore.experimental.enabled": true,
"preview_libreoffice_path": "/usr/bin/libreoffice",
"maintenance": false,
"loglevel": 3,
"memcache.distributed": "\OC\Memcache\Redis",
"memcache.local": "\OC\Memcache\Redis",
"memcache.locking": "\OC\Memcache\Redis",
"redis": {
"host": "localhost",
"port": 6379
},
"mail_smtpmode": "smtp",
"mail_from_address": "nextcloud",
"mail_domain": "xxx",
"mail_smtpauth": 1,
"mail_smtpauthtype": "PLAIN",
"mail_smtphost": "xxxx",
"mail_smtpport": "25",
"mail_smtpsecure": "tls",
"mail_smtpname": "_REMOVED SENSITIVE VALUE",
"mail_smtppassword": "_REMOVED SENSITIVE VALUE"
}
}

Are you using external storage, if yes which one: local/smb/sftp/...
no
Are you using encryption: yes/no
no
Are you using an external user-backend, if yes which one: LDAP/ActiveDirectory/Webdav/...
LDAP/ActiveDirectory

LDAP configuration

LDAP config

| Configuration | s02 |
+-------------------------------+-----------------------------------------------------------------------------------------------------------------------------------------+
| hasMemberOfFilterSupport | 1 |
| hasPagedResultSupport | |
| homeFolderNamingRule | |
| lastJpegPhotoLookup | 0 |
| ldapAgentName | CN=ncADuser,CN=Users,DC=xxx-xxx |
| ldapAgentPassword | *** |
| ldapAttributesForGroupSearch | |
| ldapAttributesForUserSearch | |
| ldapBackupHost | |
| ldapBackupPort | |
| ldapBase | DC=xxx-xxx |
| ldapBaseGroups | DC=xxx-xxx |
| ldapBaseUsers | DC=xxx-xxx |
| ldapCacheTTL | 600 |
| ldapConfigurationActive | 1 |
| ldapDynamicGroupMemberURL | |
| ldapEmailAttribute | |
| ldapExperiencedAdmin | 0 |
| ldapExpertUUIDGroupAttr | |
| ldapExpertUUIDUserAttr | |
| ldapExpertUsernameAttr | sAMAccountName |
| ldapGroupDisplayName | cn |
| ldapGroupFilter | (|(cn=Mitarbeiter)) |
| ldapGroupFilterGroups | Mitarbeiter |
| ldapGroupFilterMode | 0 |
| ldapGroupFilterObjectclass | |
| ldapGroupMemberAssocAttr | uniqueMember |
| ldapHost | ldap://xxxx |
| ldapIgnoreNamingRules | |
| ldapLoginFilter | (&(&(|(objectclass=person))(|(|(memberof=CN=Mitarbeiter,DC=xxx-xxx (primaryGroupID=1125))))(samaccountname=%uid)) |
| ldapLoginFilterAttributes | |
| ldapLoginFilterEmail | 0 |
| ldapLoginFilterMode | 0 |
| ldapLoginFilterUsername | 1 |
| ldapNestedGroups | 0 |
| ldapOverrideMainServer | |
| ldapPagingSize | 500 |
| ldapPort | 389 |
| ldapQuotaAttribute | |
| ldapQuotaDefault | |
| ldapTLS | 0 |
| ldapUserDisplayName | displayName |
| ldapUserDisplayName2 | |
| ldapUserFilter | (&(|(objectclass=person))(|(|(memberof=CN=Mitarbeiter,CN=Users,DC=xxx-xxx )(primaryGroupID=1125)))) |
| ldapUserFilterGroups | Mitarbeiter |
| ldapUserFilterMode | 0 |
| ldapUserFilterObjectclass | person |
| ldapUuidGroupAttribute | auto |
| ldapUuidUserAttribute | auto |
| turnOffCertCheck | 0 |
| useMemberOfToDetectMembership | 1 |

Client configuration

Browser:
FF49
Operating system:
W7x64

Logs

Web server error log

Web server error log

no errors

Nextcloud log (data/nextcloud.log)

Nextcloud log

Error OCP\Share Sharing backend for principals not found

Browser log

Browser log

Pls let me know which log exactly do you want.

[ggeorgg]

Same problem for me. Just tried it on a fresh installation but after creating a new calendar with user1 and sharing it with user2 I already get that Error OCP\Share Sharing backend for principals not found.

[blizzz]

Perhaps the issue lies somewhere within the dav app part in core, at least that would be a starting point to look at.

[georgehrke]

While searching for a contact to share, the app doesn't show any users.

For querying users and groups we use the endpoint of the files_sharing app.
Is the Sharing API enabled in the admin settings?

Edit: Yes, ... The calendar shouldn't show the share button when the sharing API is disabled, working on that.

[ggeorgg]

In my nextcloud admin setting the point "allow apps to use sharing API" (in german) is enabled.
I have to add, that I am not using ldap and the user with whom I shared the calendar was properly displayed when I entered the first letter of the user.

[blizzz]

This exception is thrown in lib/Share/Share::getBackend() instead. If it succeeds sometimes and sometimes not, it sounds a bit of a race condition, but this does not seem likely. Perhaps some initialization mixup, but then it should be consistent for you, still.

@schiessle do you have an idea?