Using LDAP

About LDAP authentication for GitHub Enterprise Server

LDAP is a popular application protocol for access and maintenance of directory information services, and is one of the most common protocols for integration of third-party software with large company user directories. For more information, see "Lightweight Directory Access Protocol" on Wikipedia.

If you use an LDAP directory for centralized authentication, you can configure LDAP authentication for the people who use your GitHub Enterprise Server instance.

If you want to allow authentication for some people who don't have an account on your external authentication provider, you can allow fallback authentication to local accounts on your GitHub Enterprise Server instance. For more information, see "Allowing built-in authentication for users outside your provider."

Supported LDAP services

GitHub Enterprise Server integrates with these LDAP services:

• Active Directory
• FreeIPA
• Oracle Directory Server Enterprise Edition
• OpenLDAP
• Open Directory
• 389-ds

Username considerations with LDAP

GitHub Enterprise Server normalizes a value from your external authentication provider to determine the username for each new personal account on your GitHub Enterprise Server instance. For more information, see "Username considerations for external authentication."

Configuring LDAP with your GitHub Enterprise Server instance

After you configure LDAP, users will be able to sign into your instance with their LDAP credentials. When users sign in for the first time, their profile names, email addresses, and SSH keys will be set with the LDAP attributes from your directory.

When you configure LDAP access for users via the [Management Console], your user licenses aren't used until the first time a user signs in to your instance. However, if you create an account manually using site admin settings, the user license is immediately accounted for.

1. GitHub Enterprise Server の管理アカウントから、任意のページの右上隅の をクリックします。

   

2. [サイト管理者] ページにま� 表示されていない� �合は、左上隅の [サイト管理者] をクリックします。

   

3. 左側のサイドバーで、 [Management Console] をクリックします。

4. 左サイドバーにある [Authentication](認証) をクリックします。

5. Under "Authentication", select LDAP.

6. 必要に応じて、外部認証システ� のアカウントを持たないユーザーがビルトイン認証でサインインできるようにするには、 [Allow built-in authentication](ビルトイン認証を許可する) を選択します。 詳しくは、「プロバイダー外のユーザーのためのビルトイン認証の許可」を参照してく� さい。

7. Add your configuration settings.

LDAP attributes

Use these attributes to finish configuring LDAP for your GitHub Enterprise Server instance.

Attribute name	Type	Description
Host	Required	The LDAP host, e.g. ldap.example.com or 10.0.0.30. If the hostname is only available from your internal network, you may need to configure your GitHub Enterprise Server instance's DNS first so it can resolve the hostname using your internal nameservers.
Port	Required	The port the host's LDAP services are listening on. Examples include: 389 and 636 (for LDAPS).
Encryption	Required	The encryption method used to secure communications to the LDAP server. Examples include plain (no encryption), SSL/LDAPS (encrypted from the start), and StartTLS (upgrade to encrypted communication once connected).
Domain search user	Optional	The LDAP user that looks up other users that sign in, to allow authentication. This is typically a service account created specifically for third-party integrations. Use a fully qualified name, such as cn=Administrator,cn=Users,dc=Example,dc=com. With Active Directory, you can also use the [DOMAIN]\[USERNAME] syntax (e.g. WINDOWS\Administrator) for the domain search user with Active Directory.
Domain search password	Optional	The password for the domain search user.
Administrators group	Optional	Users in this group are promoted to site administrators when signing into your appliance. If you don't configure an LDAP Administrators group, the first LDAP user account that signs into your appliance will be automatically promoted to a site administrator.
Domain base	Required	The fully qualified Distinguished Name (DN) of an LDAP subtree you want to search for users and groups. You can add as many as you like; however, each group must be defined in the same domain base as the users that belong to it. If you specify restricted user groups, only users that belong to those groups will be in scope. We recommend that you specify the top level of your LDAP directory tree as your domain base and use restricted user groups to control access.
Restricted user groups	Optional	If specified, only users in these groups will be allowed to log in. You only need to specify the common names (CNs) of the groups, and you can add as many groups as you like. If no groups are specified, all users within the scope of the specified domain base will be able to sign in to your GitHub Enterprise Server instance.
User ID	Required	The LDAP attribute that identifies the LDAP user who attempts authentication. Once a mapping is established, users may change their GitHub Enterprise Server usernames. This field should be sAMAccountName for most Active Directory installations, but it may be uid for other LDAP solutions, such as OpenLDAP. The default value is uid.
Profile name	Optional	The name that will appear on the user's GitHub Enterprise Server profile page. Unless LDAP Sync is enabled, users may change their profile names.
Emails	Optional	The email addresses for a user's GitHub Enterprise Server account.
SSH keys	Optional	The public SSH keys attached to a user's GitHub Enterprise Server account. The keys must be in OpenSSH format.
GPG keys	Optional	The GPG keys attached to a user's GitHub Enterprise Server account.
Disable LDAP authentication for Git operations	Optional	If selected, turns off users' ability to use LDAP passwords to authenticate Git operations.
Enable LDAP certificate verification	Optional	If selected, turns on LDAP certificate verification.
Synchronization	Optional	If selected, turns on LDAP Sync.

Disabling password authentication for Git operations

Select Disable username and password authentication for Git operations in your LDAP settings to enforce use of personal access tokens or SSH keys for Git access, which can help prevent your server from being overloaded by LDAP authentication requests. We recommend this setting because a slow-responding LDAP server, especially combined with a large number of requests due to polling, is a frequent source of performance issues and outages.

When this option is selected, if a user tries to use a password for Git operations via the command line, they will receive an error message that says, Password authentication is not allowed for Git operations. You must use a personal access token.

Enabling LDAP certificate verification

Select Enable LDAP certificate verification in your LDAP settings to validate the LDAP server certificate you use with TLS.

When this option is selected, the certificate is validated to make sure:

• If the certificate contains at least one Subject Alternative Name (SAN), one of the SANs matches the LDAP hostname. Otherwise, the Common Name (CN) matches the LDAP hostname.
• The certificate is not expired.
• The certificate is signed by a trusted certificate authority (CA).

Enabling LDAP Sync

LDAP Sync lets you synchronize GitHub Enterprise Server users and team membership against your established LDAP groups. This lets you establish role-based access control for users from your LDAP server instead of manually within GitHub Enterprise Server. For more information, see "Creating teams."

To enable LDAP Sync, in your LDAP settings, select Synchronize Emails, Synchronize SSH Keys, or Synchronize GPG Keys .

After you enable LDAP sync, a synchronization job will run at the specified time interval to perform the following operations on each user account:

• If you've allowed built-in authentication for users outside your identity provider, and the user is using built-in authentication, move on to the next user.
• If no LDAP mapping exists for the user, try to map the user to an LDAP entry in the directory. If the user cannot be mapped to an LDAP entry, suspend the user and move on to the next user.
• If there is an LDAP mapping and the corresponding LDAP entry in the directory is missing, suspend the user and move on to the next user.
• If the corresponding LDAP entry has been marked as disabled and the user is not already suspended, suspend the user and move on to the next user.
• If the corresponding LDAP entry is not marked as disabled, and the user is suspended, and Reactivate suspended users is enabled in the Admin Center, unsuspend the user.
• If one or more restricted user groups are configured on the instance and the corresponding LDAP entry is not in one of these groups, suspend the user.
• If one or more restricted user groups are configured on the instance, the corresponding LDAP entry is in one of these groups, and Reactivate suspended users is enabled in the Admin Center, unsuspend the user.
• If the corresponding LDAP entry includes a name attribute, update the user's profile name.
• If the corresponding LDAP entry is in the Administrators group, promote the user to site administrator.
• If the corresponding LDAP entry is not in the Administrators group, demote the user to a normal account.
• If an LDAP User field is defined for emails, synchronize the user's email settings with the LDAP entry. Set the first LDAP mail entry as the primary email.
• If an LDAP User field is defined for SSH public keys, synchronize the user's public SSH keys with the LDAP entry.
• If an LDAP User field is defined for GPG keys, synchronize the user's GPG keys with the LDAP entry.

A synchronization job will also run at the specified time interval to perform the following operations on each team that has been mapped to an LDAP group:

• If a team's corresponding LDAP group has been removed, remove all members from the team.

• If LDAP member entries have been removed from the LDAP group, remove the corresponding users from the team. If the user is no longer a member of any team in the organization, remove the user from the organization. If the user loses access to any repositories as a result, delete any private forks the user has of those repositories.

• If LDAP member entries have been added to the LDAP group, add the corresponding users to the team. If the user regains access to any repositories as a result, restore any private forks of the repositories that were deleted because the user lost access in the past 90 days.

  LDAP 同期は、最適化構成の一部として、入れ子チー� の構� を転送しません。 親子Teamの関係を作りたい� �合は、入れ子チー� の構� を手動で再作成し、対応するLDAPグループに同期させなければなりません。 詳細については、「チー� の作成」を参照してく� さい

Supported LDAP group object classes

GitHub Enterprise Server supports these LDAP group object classes. Groups can be nested.

• group
• groupOfNames
• groupOfUniqueNames
• posixGroup

Viewing and creating LDAP users

You can view the full list of LDAP users who have access to your instance and provision new users.

1. Sign in to your GitHub Enterprise Server instance at http(s)://HOSTNAME/login.

2. GitHub Enterprise Server の管理アカウントから、任意のページの右上隅の をクリックします。

   

3. [サイト管理者] ページにま� 表示されていない� �合は、左上隅の [サイト管理者] をクリックします。

   

4. In the left sidebar, click LDAP users.

5. To search for a user, type a full or partial username and click Search. Existing users will be displayed in search results. If a user doesn’t exist, click Create to provision the new user account.

Updating LDAP accounts

Unless LDAP Sync is enabled, changes to LDAP accounts are not automatically synchronized with GitHub Enterprise Server.

• To use a new LDAP admin group, users must be manually promoted and demoted on GitHub Enterprise Server to reflect changes in LDAP.
• To add or remove LDAP accounts in LDAP admin groups, promote or demote the accounts on GitHub Enterprise Server.
• To remove LDAP accounts, suspend the GitHub Enterprise Server accounts.

Manually syncing LDAP accounts

1. Sign in to your GitHub Enterprise Server instance at http(s)://HOSTNAME/login.

2. GitHub Enterprise Server の管理アカウントから、任意のページの右上隅の をクリックします。

   

3. [サイト管理者] ページにま� 表示されていない� �合は、左上隅の [サイト管理者] をクリックします。

   

4. 検索フィールドにユーザーの名前を入力し、 [検索] をクリックします。

5. 検索結果で、ユーザ名をクリックしてく� さい。

6. ページの右上隅にある [管理者] をクリックします。

7. 左側のサイドバーで、 [管理者] をクリックします。

8. Under "LDAP," click Sync now to manually update the account with data from your LDAP server.

You can also use the API to trigger a manual sync.

Revoking access to your GitHub Enterprise Server instance

If LDAP Sync is enabled, removing a user's LDAP credentials will suspend their account after the next synchronization run.

If LDAP Sync is not enabled, you must manually suspend the GitHub Enterprise Server account after you remove the LDAP credentials. For more information, see "Suspending and unsuspending users".