1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
|
---
type: reference
stage: Manage
group: Authentication and Authorization
info: To determine the technical writer assigned to the Stage/Group associated with this page, see https://about.gitlab.com/handbook/product/ux/technical-writing/#assignments
---
# Integrate LDAP with GitLab **(FREE SELF)**
GitLab integrates with [LDAP - Lightweight Directory Access Protocol](https://en.wikipedia.org/wiki/Lightweight_Directory_Access_Protocol)
to support user authentication.
This integration works with most LDAP-compliant directory servers, including:
- Microsoft Active Directory.
[Microsoft Active Directory Trusts](https://learn.microsoft.com/en-us/previous-versions/windows/it-pro/windows-server-2008-R2-and-2008/cc771568(v=ws.10))
are not supported.
- Apple Open Directory.
- Open LDAP.
- 389 Server.
Users added through LDAP:
- Usually use a [licensed seat](../../../subscriptions/self_managed/index.md#billable-users).
- Can authenticate with Git using either their GitLab username or their email and LDAP password,
even if password authentication for Git
[is disabled](../../../user/admin_area/settings/sign_in_restrictions.md#password-authentication-enabled).
The LDAP DN is associated with existing GitLab users when:
- The existing user signs in to GitLab with LDAP for the first time.
- The LDAP email address is the primary email address of an existing GitLab user. If the LDAP email
attribute isn't found in the GitLab user database, a new user is created.
If an existing GitLab user wants to enable LDAP sign-in for themselves, they should:
1. Check that their GitLab email address matches their LDAP email address.
1. Sign in to GitLab by using their LDAP credentials.
## Security
GitLab has multiple mechanisms to verify a user is still active in LDAP. If the user is no longer active in
LDAP, they are placed in an `ldap_blocked` status and are signed out. They are unable to sign in using any authentication provider until they are
reactivated in LDAP.
Users are considered inactive in LDAP when they:
- Are removed from the directory completely.
- Reside outside the configured `base` DN or `user_filter` search.
- Are marked as disabled or deactivated in Active Directory through the user account control attribute. This means attribute
`userAccountControl:1.2.840.113556.1.4.803` has bit 2 set.
Status is checked for all LDAP users:
- When signing in using any authentication provider. [In GitLab 14.4 and earlier](https://gitlab.com/gitlab-org/gitlab/-/issues/343298), status was
checked only when signing in using LDAP directly.
- Once per hour for active web sessions or Git requests using tokens or SSH keys.
- When performing Git over HTTP requests using LDAP username and password.
- Once per day during [User Sync](ldap_synchronization.md#user-sync).
### Security risks
You should only use LDAP integration if your LDAP users cannot:
- Change their `mail`, `email` or `userPrincipalName` attributes on the LDAP server. These
users can potentially take over any account on your GitLab server.
- Share email addresses. LDAP users with the same email address can share the same GitLab
account.
## Configure LDAP
To configure LDAP integration, add your LDAP server settings in:
- `/etc/gitlab/gitlab.rb` for Omnibus GitLab instances.
- `/home/git/gitlab/config/gitlab.yml` for source install instances.
After configuring LDAP, to test the configuration, use the
[LDAP check Rake task](../../raketasks/ldap.md#check).
NOTE:
The `encryption` value `simple_tls` corresponds to 'Simple TLS' in the LDAP
library. `start_tls` corresponds to StartTLS, not to be confused with regular TLS.
Normally, if you specify `simple_tls` it is on port 636, while `start_tls` (StartTLS)
would be on port 389. `plain` also operates on port 389. Removed values: `tls` was replaced
with `start_tls` and `ssl` was replaced with `simple_tls`.
LDAP users must have a set email address, regardless of whether or not it's used
to sign in.
### Example Omnibus GitLab configuration
This example shows configuration for Omnibus GitLab instances:
```ruby
gitlab_rails['ldap_enabled'] = true
gitlab_rails['prevent_ldap_sign_in'] = false
gitlab_rails['ldap_servers'] = {
'main' => {
'label' => 'LDAP',
'host' => 'ldap.mydomain.com',
'port' => 636,
'uid' => 'sAMAccountName',
'encryption' => 'simple_tls',
'verify_certificates' => true,
'bind_dn' => '_the_full_dn_of_the_user_you_will_bind_with',
'password' => '_the_password_of_the_bind_user',
'tls_options' => {
'ca_file' => '',
'ssl_version' => '',
'ciphers' => '',
'cert' => '',
'key' => ''
},
'timeout' => 10,
'active_directory' => true,
'allow_username_or_email_login' => false,
'block_auto_created_users' => false,
'base' => 'dc=example,dc=com',
'user_filter' => '',
'attributes' => {
'username' => ['uid', 'userid', 'sAMAccountName'],
'email' => ['mail', 'email', 'userPrincipalName'],
'name' => 'cn',
'first_name' => 'givenName',
'last_name' => 'sn'
},
'lowercase_usernames' => false,
# EE Only
'group_base' => '',
'admin_group' => '',
'external_groups' => [],
'sync_ssh_keys' => false
}
}
```
### Example source install configuration
This example shows configuration for source install instances:
```yaml
production:
# snip...
ldap:
enabled: false
prevent_ldap_sign_in: false
servers:
main:
label: 'LDAP'
...
```
### Basic configuration settings
> `hosts` configuration setting [introduced](https://gitlab.com/gitlab-org/gitlab/-/issues/139) in GitLab 14.7.
You can configure either:
- A single LDAP server using `host` and `port`.
- Many LDAP servers using `hosts`. This setting takes precedence over `host` and `port`. GitLab attempts to use the
LDAP servers in the order specified, and the first reachable LDAP server is used.
These configuration settings are available:
| Setting | Description | Required | Examples |
|--------------------|-------------|----------|----------|
| `label` | A human-friendly name for your LDAP server. It is displayed on your sign-in page. | **{check-circle}** Yes | `'Paris'` or `'Acme, Ltd.'` |
| `host` | IP address or domain name of your LDAP server. Ignored when `hosts` is defined. | **{check-circle}** Yes | `'ldap.mydomain.com'` |
| `port` | The port to connect with on your LDAP server. Always an integer, not a string. Ignored when `hosts` is defined. | **{check-circle}** Yes | `389` or `636` (for SSL) |
| `hosts` (GitLab 14.7 and later) | An array of host and port pairs to open connections. | **{dotted-circle}** No | `[['ldap1.mydomain.com', 636], ['ldap2.mydomain.com', 636]]` |
| `uid` | The LDAP attribute that maps to the username that users use to sign in. Should be the attribute, not the value that maps to the `uid`. Does not affect the GitLab username (see [attributes section](#attribute-configuration-settings)). | **{check-circle}** Yes | `'sAMAccountName'` or `'uid'` or `'userPrincipalName'` |
| `bind_dn` | The full DN of the user you bind with. | **{dotted-circle}** No | `'america\momo'` or `'CN=Gitlab,OU=Users,DC=domain,DC=com'` |
| `password` | The password of the bind user. | **{dotted-circle}** No | `'your_great_password'` |
| `encryption` | Encryption method. The `method` key is deprecated in favor of `encryption`. | **{check-circle}** Yes | `'start_tls'` or `'simple_tls'` or `'plain'` |
| `verify_certificates` | Enables SSL certificate verification if encryption method is `start_tls` or `simple_tls`. If set to false, no validation of the LDAP server's SSL certificate is performed. Defaults to true. | **{dotted-circle}** No | boolean |
| `timeout` | Set a timeout, in seconds, for LDAP queries. This helps avoid blocking a request if the LDAP server becomes unresponsive. A value of `0` means there is no timeout. (default: `10`) | **{dotted-circle}** No | `10` or `30` |
| `active_directory` | This setting specifies if LDAP server is Active Directory LDAP server. For non-AD servers it skips the AD specific queries. If your LDAP server is not AD, set this to false. | **{dotted-circle}** No | boolean |
| `allow_username_or_email_login` | If enabled, GitLab ignores everything after the first `@` in the LDAP username submitted by the user on sign-in. If you are using `uid: 'userPrincipalName'` on ActiveDirectory you must disable this setting, because the userPrincipalName contains an `@`. | **{dotted-circle}** No | boolean |
| `block_auto_created_users` | To maintain tight control over the number of billable users on your GitLab installation, enable this setting to keep new users blocked until they have been cleared by an administrator (default: false). | **{dotted-circle}** No | boolean |
| `base` | Base where we can search for users. | **{check-circle}** Yes | `'ou=people,dc=gitlab,dc=example'` or `'DC=mydomain,DC=com'` |
| `user_filter` | Filter LDAP users. Format: [RFC 4515](https://tools.ietf.org/search/rfc4515) Note: GitLab does not support `omniauth-ldap`'s custom filter syntax. | **{dotted-circle}** No | For examples, read [Examples of user filters](#examples-of-user-filters). |
| `lowercase_usernames` | If enabled, GitLab converts the name to lower case. | **{dotted-circle}** No | boolean |
| `retry_empty_result_with_codes` | An array of LDAP query response code that attempt to retry the operation if the result/content is empty. For Google Secure LDAP, set this value to `[80]`. | **{dotted-circle}** No | `[80]` |
#### Examples of user filters
Some examples of the `user_filter` field syntax:
- `'(employeeType=developer)'`
- `'(&(objectclass=user)(|(samaccountname=momo)(samaccountname=toto)))'`
### SSL configuration settings
These SSL configuration settings are available:
| Setting | Description | Required | Examples |
|---------------|-------------|----------|----------|
| `ca_file` | Specifies the path to a file containing a PEM-format CA certificate, for example, if you need an internal CA. | **{dotted-circle}** No | `'/etc/ca.pem'` |
| `ssl_version` | Specifies the SSL version for OpenSSL to use, if the OpenSSL default is not appropriate. | **{dotted-circle}** No | `'TLSv1_1'` |
| `ciphers` | Specific SSL ciphers to use in communication with LDAP servers. | **{dotted-circle}** No | `'ALL:!EXPORT:!LOW:!aNULL:!eNULL:!SSLv2'` |
| `cert` | Client certificate. | **{dotted-circle}** No | `'-----BEGIN CERTIFICATE----- <REDACTED> -----END CERTIFICATE -----'` |
| `key` | Client private key. | **{dotted-circle}** No | `'-----BEGIN PRIVATE KEY----- <REDACTED> -----END PRIVATE KEY -----'` |
### Attribute configuration settings
GitLab uses these LDAP attributes to create an account for the LDAP user. The specified
attribute can be either:
- The attribute name as a string. For example, `'mail'`.
- An array of attribute names to try in order. For example, `['mail', 'email']`.
The user's LDAP sign in is the LDAP attribute [specified as `uid`](#basic-configuration-settings).
| Setting | Description | Required | Examples |
|--------------|-------------|----------|----------|
| `username` | Used in paths for the user's own projects (for example, `gitlab.example.com/username/project`) and when mentioning them in issues, merge request and comments (for example, `@username`). If the attribute specified for `username` contains an email address, the GitLab username is part of the email address before the `@`. | **{dotted-circle}** No | `['uid', 'userid', 'sAMAccountName']` |
| `email` | LDAP attribute for user email. | **{dotted-circle}** No | `['mail', 'email', 'userPrincipalName']` |
| `name` | LDAP attribute for user display name. If `name` is blank, the full name is taken from the `first_name` and `last_name`. | **{dotted-circle}** No | Attributes `'cn'`, or `'displayName'` commonly carry full names. Alternatively, you can force the use of `first_name` and `last_name` by specifying an absent attribute such as `'somethingNonExistent'`. |
| `first_name` | LDAP attribute for user first name. Used when the attribute configured for `name` does not exist. | **{dotted-circle}** No | `'givenName'` |
| `last_name` | LDAP attribute for user last name. Used when the attribute configured for `name` does not exist. | **{dotted-circle}** No | `'sn'` |
### LDAP sync configuration settings **(PREMIUM SELF)**
These LDAP sync configuration settings are available:
| Setting | Description | Required | Examples |
|-------------------|-------------|----------|----------|
| `group_base` | Base used to search for groups. | **{dotted-circle}** No | `'ou=groups,dc=gitlab,dc=example'` |
| `admin_group` | The CN of a group containing GitLab administrators. Not `cn=administrators` or the full DN. | **{dotted-circle}** No | `'administrators'` |
| `external_groups` | An array of CNs of groups containing users that should be considered external. Not `cn=interns` or the full DN. | **{dotted-circle}** No | `['interns', 'contractors']` |
| `sync_ssh_keys` | The LDAP attribute containing a user's public SSH key. | **{dotted-circle}** No | `'sshPublicKey'` or false if not set |
### Use multiple LDAP servers **(PREMIUM SELF)**
If you have users on multiple LDAP servers, you can configure GitLab to use them. To add additional LDAP servers:
1. Duplicate the [`main` LDAP configuration](#configure-ldap).
1. Edit each duplicate configuration with the details of the additional servers.
- For each additional server, choose a different provider ID, like `main`, `secondary`, or `tertiary`. Use lowercase
alphanumeric characters. GitLab uses the provider ID to associate each user with a specific LDAP server.
- For each entry, use a unique `label` value. These values are used for the tab names on the sign-in page.
#### Example of multiple LDAP servers
The following example shows how to configure three LDAP servers in `gitlab.rb`:
```ruby
gitlab_rails['ldap_enabled'] = true
gitlab_rails['ldap_servers'] = {
'main' => {
'label' => 'GitLab AD',
'host' => 'ad.example.org',
'port' => 636,
...
},
'secondary' => {
'label' => 'GitLab Secondary AD',
'host' => 'ad-secondary.example.net',
'port' => 636,
...
},
'tertiary' => {
'label' => 'GitLab Tertiary AD',
'host' => 'ad-tertiary.example.net',
'port' => 636,
...
}
}
```
This example results in a sign-in page with the following tabs:
- **GitLab AD**.
- **GitLab Secondary AD**.
- **GitLab Tertiary AD**.
### Set up LDAP user filter
To limit all GitLab access to a subset of the LDAP users on your LDAP server, first narrow the
configured `base`. However, to further filter users if
necessary, you can set up an LDAP user filter. The filter must comply with [RFC 4515](https://tools.ietf.org/search/rfc4515).
- Example user filter for Omnibus GitLab instances:
```ruby
gitlab_rails['ldap_servers'] = {
'main' => {
# snip...
'user_filter' => '(employeeType=developer)'
}
}
```
- Example user filter for source install instances:
```yaml
production:
ldap:
servers:
main:
# snip...
user_filter: '(employeeType=developer)'
```
To limit access to the nested members of an Active Directory group, use the following syntax:
```plaintext
(memberOf:1.2.840.113556.1.4.1941:=CN=My Group,DC=Example,DC=com)
```
For more information about `LDAP_MATCHING_RULE_IN_CHAIN` filters, see
[Search Filter Syntax](https://learn.microsoft.com/en-us/windows/win32/adsi/search-filter-syntax).
Support for nested members in the user filter shouldn't be confused with
[group sync nested groups](ldap_synchronization.md#supported-ldap-group-typesattributes) support.
GitLab does not support the custom filter syntax used by OmniAuth LDAP.
#### Escape special characters
The `user_filter` DN can contain special characters. For example:
- A comma:
```plaintext
OU=GitLab, Inc,DC=gitlab,DC=com
```
- Open and close brackets:
```plaintext
OU=Gitlab (Inc),DC=gitlab,DC=com
```
These characters must be escaped as documented in
[RFC 4515](https://tools.ietf.org/search/rfc4515).
- Escape commas with `\2C`. For example:
```plaintext
OU=GitLab\2C Inc,DC=gitlab,DC=com
```
- Escape open brackets with `\28` and close brackets with `\29`. For example:
```plaintext
OU=Gitlab \28Inc\29,DC=gitlab,DC=com
```
### Enable LDAP username lowercase
Some LDAP servers, depending on their configurations, can return uppercase usernames.
This can lead to several confusing issues such as creating links or namespaces with uppercase names.
GitLab can automatically lowercase usernames provided by the LDAP server by enabling
the configuration option `lowercase_usernames`. By default, this configuration option is `false`.
**Omnibus configuration**
1. Edit `/etc/gitlab/gitlab.rb`:
```ruby
gitlab_rails['ldap_servers'] = {
'main' => {
# snip...
'lowercase_usernames' => true
}
}
```
1. [Reconfigure GitLab](../../restart_gitlab.md#omnibus-gitlab-reconfigure) for the changes to take effect.
**Source configuration**
1. Edit `config/gitlab.yaml`:
```yaml
production:
ldap:
servers:
main:
# snip...
lowercase_usernames: true
```
1. [Restart GitLab](../../restart_gitlab.md#installations-from-source) for the changes to take effect.
### Disable LDAP web sign in
It can be useful to prevent using LDAP credentials through the web UI when
an alternative such as SAML is preferred. This allows LDAP to be used for group
sync, while also allowing your SAML identity provider to handle additional
checks like custom 2FA.
When LDAP web sign in is disabled, users don't see an **LDAP** tab on the sign-in page.
This does not disable using LDAP credentials for Git access.
**Omnibus configuration**
1. Edit `/etc/gitlab/gitlab.rb`:
```ruby
gitlab_rails['prevent_ldap_sign_in'] = true
```
1. [Reconfigure GitLab](../../restart_gitlab.md#omnibus-gitlab-reconfigure) for the changes to take effect.
**Source configuration**
1. Edit `config/gitlab.yaml`:
```yaml
production:
ldap:
prevent_ldap_sign_in: true
```
1. [Restart GitLab](../../restart_gitlab.md#installations-from-source) for the changes to take effect.
### Use encrypted credentials
Instead of having the LDAP integration credentials stored in plaintext in the configuration files, you can optionally
use an encrypted file for the LDAP credentials. To use this feature, first you must enable
[GitLab encrypted configuration](../../encrypted_configuration.md).
The encrypted configuration for LDAP exists in an encrypted YAML file. By default the file is created at
`shared/encrypted_configuration/ldap.yaml.enc`. This location is configurable in the GitLab configuration.
The unencrypted contents of the file should be a subset of the secret settings from your `servers` block in the LDAP
configuration.
The supported configuration items for the encrypted file are:
- `bind_dn`
- `password`
The encrypted contents can be configured with the [LDAP secret edit Rake command](../../raketasks/ldap.md#edit-secret).
**Omnibus configuration**
If initially your LDAP configuration looked like:
1. In `/etc/gitlab/gitlab.rb`:
```ruby
gitlab_rails['ldap_servers'] = {
'main' => {
# snip...
'bind_dn' => 'admin',
'password' => '123'
}
}
```
1. Edit the encrypted secret:
```shell
sudo gitlab-rake gitlab:ldap:secret:edit EDITOR=vim
```
1. The unencrypted contents of the LDAP secret should be entered like:
```yaml
main:
bind_dn: admin
password: '123'
```
1. Edit `/etc/gitlab/gitlab.rb` and remove the settings for `bind_dn` and `password`.
1. [Reconfigure GitLab](../../restart_gitlab.md#omnibus-gitlab-reconfigure) for the changes to take effect.
**Source configuration**
If initially your LDAP configuration looked like:
1. In `config/gitlab.yaml`:
```yaml
production:
ldap:
servers:
main:
# snip...
bind_dn: admin
password: '123'
```
1. Edit the encrypted secret:
```shell
bundle exec rake gitlab:ldap:secret:edit EDITOR=vim RAILS_ENVIRONMENT=production
```
1. The unencrypted contents of the LDAP secret should be entered like:
```yaml
main:
bind_dn: admin
password: '123'
```
1. Edit `config/gitlab.yaml` and remove the settings for `bind_dn` and `password`.
1. [Restart GitLab](../../restart_gitlab.md#installations-from-source) for the changes to take effect.
## Disable anonymous LDAP authentication
GitLab doesn't support TLS client authentication. Complete these steps on your LDAP server.
1. Disable anonymous authentication.
1. Enable one of the following authentication types:
- Simple authentication.
- Simple Authentication and Security Layer (SASL) authentication.
The TLS client authentication setting in your LDAP server cannot be mandatory and clients cannot be
authenticated with the TLS protocol.
## Users deleted from LDAP
Users deleted from the LDAP server:
- Are immediately blocked from signing in to GitLab.
- [No longer consume a license](../../../user/admin_area/moderate_users.md).
However, these users can continue to use Git with SSH until the next time the
[LDAP check cache runs](ldap_synchronization.md#adjust-ldap-user-sync-schedule).
To delete the account immediately, you can manually
[block the user](../../../user/admin_area/moderate_users.md#block-a-user).
## Update user email addresses
Email addresses on the LDAP server are considered the source of truth for users when LDAP is used to sign in.
Updating user email addresses must be done on the LDAP server that manages the user. The email address for GitLab is updated either:
- When the user next signs in.
- When the next [user sync](ldap_synchronization.md#user-sync) is run.
The updated user's previous email address becomes the secondary email address to preserve that user's commit history.
You can find more details on the expected behavior of user updates in our [LDAP troubleshooting section](ldap-troubleshooting.md#user-dn-orand-email-have-changed).
## Google Secure LDAP
> Introduced in GitLab 11.9.
[Google Cloud Identity](https://cloud.google.com/identity/) provides a Secure
LDAP service that can be configured with GitLab for authentication and group sync.
See [Google Secure LDAP](google_secure_ldap.md) for detailed configuration instructions.
## Synchronize users and groups
For more information on synchronizing users and groups between LDAP and GitLab, see
[LDAP synchronization](ldap_synchronization.md).
## Troubleshooting
See our [administrator guide to troubleshooting LDAP](ldap-troubleshooting.md).
|