SAML on GitLab.com allows users to be added to a group. Those users can then sign in to GitLab.com. If such users don't already have an account on the GitLab instance, they can create one when signing in for the first time.
If you follow our guidance to automate user provisioning using [SCIM](scim_setup.md) or [group managed accounts](#group-managed-accounts), you do not need to create such accounts manually.
1. Configure your SAML server using the **Assertion consumer service URL** and **Identifier**. Alternatively GitLab provides [metadata XML configuration](#metadata-configuration). See [your identity provider's documentation](#providers) for more details.
GitLab.com uses the SAML NameID to identify users. The NameID element:
- Is a required field in the SAML response.
- Must be unique to each user.
- Must be a persistent value that will never change, such as a randomly generated unique user ID.
- Is case sensitive. The NameID must match exactly on subsequent login attempts, so should not rely on user input that could change between upper and lower case.
- Should not be an email address or username. We strongly recommend against these as it is hard to guarantee they will never change, for example when a person's name changes. Email addresses are also case-insensitive, which can result in users being unable to sign in.
CAUTION: **Warning:**
Once users have signed into GitLab using the SSO SAML setup, changing the `NameID` will break the configuration and potentially lock users out of the GitLab group.
#### NameID Format
We recommend setting the NameID format to `Persistent` unless using a field (such as email) that requires a different format.
With this option enabled, users must use your group's GitLab single sign on URL to be added to the group or be added via SCIM. Users cannot be added manually, and may only access project/group resources via the UI by signing in through the SSO URL.
However, users will not be prompted to log via SSO on each visit. GitLab will check whether a user has authenticated through the SSO link, and will only prompt the user to login via SSO if it has been longer than 7 days.
When SSO is being enforced, groups can enable an additional level of protection by enforcing the creation of dedicated user accounts to access the group.
Without group-managed accounts, users can link their SAML identity with any existing user on the instance. With group-managed accounts enabled, users are required to create a new, dedicated user linked to the group. The notification email address associated with the user is locked to the email address received from the configured identity provider.
When this option is enabled:
- All existing and new users in the group will be required to log in via the SSO URL associated with the group.
- Users can't share a project in the group outside the top-level group (also applies to forked projects).
Upon successful authentication, GitLab prompts the user with options, based on the email address received from the configured identity provider:
- To create a unique account with the newly received email address.
- If the received email address matches one of the user's verified GitLab email addresses, the option to convert the existing account to a group-managed account. ([Introduced in GitLab 12.9](https://gitlab.com/gitlab-org/gitlab/issues/13481).)
Since use of the group-managed account requires the use of SSO, users of group-managed accounts will lose access to these accounts when they are no longer able to authenticate with the connected identity provider. In the case of an offboarded employee who has been removed from your identity provider:
Once Group SSO is configured and enabled, users can access the GitLab.com group through the identity provider's dashboard. If [SCIM](scim_setup.md) is configured, please see the [user access and linking setup section on the SCIM page](scim_setup.md#user-access-and-linking-setup).
When a user tries to sign in with Group SSO, they'll need an account that's configured with one of the following:
1. Click on the GitLab app in the identity provider's dashboard, or visit the Group's GitLab SSO URL.
1. Sign in to GitLab.com. The next time you connect on the same browser, you won't have to sign in again provided the active session has not expired.
1. Click on the **Authorize** button.
On subsequent visits, users can access the group through the identify provider's dashboard or by visiting links directly. With the **enforce SSO** option turned on, users will be redirected to log in through the identity provider as required.
### Role
Upon first sign in, a new user is added to the parent group with the Guest role. Existing members with an appropriate role will have to elevate users to a higher role where relevant.
If a user is already a member of the group, linking the SAML identity does not change their role.
### Blocking access
To rescind access to the group:
1. Remove the user from the identity provider or users list for the specific app.
1. Remove the user from the GitLab.com group.
Even when **enforce SSO** is active, we recommend removing the user from the group. Otherwise, the user can sign in through the identity provider if they do not have an active session.
| Azure | [Configuring single sign-on to applications](https://docs.microsoft.com/en-us/azure/active-directory/manage-apps/configure-single-sign-on-non-gallery-applications) |
| Ping One for Enterprise | [Add and configure a new SAML application](https://support.pingidentity.com/s/document-item?bundleId=pingone&topicId=xsh1564020480660-1.html) |
When [configuring your identify provider](#configuring-your-identity-provider), please consider the notes below for specific providers to help avoid common issues and as a guide for terminology used.
GitLab [isn't limited to the SAML providers listed above](#my-identity-provider-isnt-listed) but your Identity Provider may require additional configuration, such as the following:
| Field | Value | Notes |
|-------|-------|-------|
| SAML Profile | Web browser SSO profile | GitLab uses SAML to sign users in via their browser. We don't make requests direct to the Identity Provider. |
| SAML Request Binding | HTTP Redirect | GitLab (the service provider) redirects users to your Identity Provider with a base64 encoded `SAMLRequest` HTTP parameter. |
| SAML Response Binding | HTTP POST | Your Identity Provider responds to users with an HTTP form including the `SAMLResponse`, which a user's browser submits back to GitLab. |
| Sign SAML Response | Yes | We require this to prevent tampering. |
| X509 Certificate in response | Yes | This is used to sign the response and checked against the provided fingerprint. |
| Fingerprint Algorithm | SHA-1 | We need a SHA-1 hash of the certificate used to sign the SAML Response. |
| Signature Algorithm | SHA-1/SHA-256/SHA-384/SHA-512 | Also known as the Digest Method, this can be specified in the SAML response. It determines how a response is signed. |
| Encrypt SAML Assertion | No | TLS is used between your Identity Provider, the user's browser, and GitLab. |
| Sign SAML Assertion | Optional | We don't require Assertions to be signed. We validate their integrity by requiring the whole response to be signed. |
| Check SAML Request Signature | No | GitLab does not sign SAML requests, but does check the signature on the SAML response. |
| Default RelayState | Optional | The URL users should end up on after signing in via a button on your Identity Provider. |
| NameID Format | `Persistent` | See [details above](#nameid-format). |
| Additional URLs | | You may need to use the `Identifier` or `Assertion consumer service URL` in other fields on some providers. |
| Single Sign Out URL | | Not supported |
If the information information you need isn't listed above you may wish to check our [troubleshooting docs below](#i-need-additional-information-to-configure-my-identity-provider).
## Linking SAML to your existing GitLab.com account
To link SAML to your existing GitLab.com account:
1. Sign in to your GitLab.com account.
1. Locate the SSO URL for the group you are signing in to. A group Admin can find this on the group's **Settings > SAML SSO** page.
1. Visit the SSO URL and click **Authorize**.
1. Enter your credentials on the Identity Provider if prompted.
1. You will be redirected back to GitLab.com and should now have access to the group. In the future, you can use SAML to sign in to GitLab.com.
## Signing in to GitLab.com with SAML
1. Locate the SSO URL for the group you are signing in to. A group Admin can find this on a group's **Settings > SAML SSO** page. If configured, it might also be possible to sign in to GitLab starting from your Identity Provider.
1. Visit the SSO URL and click the **Sign in with Single Sign-On** button.
1. Enter your credentials on the Identity Provider if prompted.
1. You will be signed in to GitLab.com and redirected to the group.
| Service Provider | SAML considers GitLab to be a service provider. |
| Assertion | A piece of information about a user's identity, such as their name or role. Also know as claims or attributes. |
| SSO | Single Sign On. |
| Assertion consumer service URL | The callback on GitLab where users will be redirected after successfully authenticating with the identity provider. |
| Issuer | How GitLab identifies itself to the identity provider. Also known as a "Relying party trust identifier". |
| Certificate fingerprint | Used to confirm that communications over SAML are secure by checking that the server is signing communications with the correct certificate. Also known as a certificate thumbprint. |
- The [NameID](#nameid), which we use to identify which user is signing in. If the user has previously signed in, this [must match the value we have stored](#verifying-nameid).
- The presence of a `X509Certificate`, which we require to verify the response signature.
- The `SubjectConfirmation` and `Conditions`, which can cause errors if misconfigured.
For convenience, we've included some [example resources](../../../administration/troubleshooting/group_saml_scim.md) used by our Support Team. While they may help you verify the SAML app configuration, they are not guaranteed to reflect the current state of third-party products.
In troubleshooting the Group SAML setup, any authenticated user can use the API to verify the NameID GitLab already has linked to the user by visiting [https://gitlab.com/api/v4/user](https://gitlab.com/api/v4/user) and checking the `extern_uid` under identities.
Similarly, group members of a role with the appropriate permissions can make use of the [members API](../../../api/members.md) to view group SAML identity information for members of the group.
This can then be compared to the [NameID](#nameid) being sent by the Identity Provider by decoding the message with a [SAML debugging tool](#saml-debugging-tools). We require that these match in order to identify users.
### Message: "SAML authentication failed: Extern uid has already been taken"
This error suggests you are signed in as a GitLab user but have already linked your SAML identity to a different GitLab user. Sign out and then try to sign in again using the SSO SAML link, which should log you into GitLab with the linked user account.
If you do not wish to use that GitLab user with the SAML login, you can [unlink the GitLab account from the group's SAML](#unlinking-accounts).
### Message: "SAML authentication failed: User has already been taken"
The user you are signed in with already has SAML linked to a different identity. This might mean you've attempted to link multiple SAML identities to the same user for a given Identity Provider. This could also be a symptom of the Identity Provider returning an inconsistent [NameID](#nameid).
To change which identity you sign in with, you can [unlink the previous SAML identity](#unlinking-accounts) from this GitLab account.
### Message: "SAML authentication failed: Extern uid has already been taken, User has already been taken"
Getting both of these errors at the same time suggests the NameID capitalization provided by the Identity Provider didn't exactly match the previous value for that user.
This can be prevented by configuring the [NameID](#nameid) to return a consistent value. Fixing this for an individual user involves [unlinking SAML in the GitLab account](#unlinking-accounts), although this will cause group membership and Todos to be lost.
Not a problem, the SAML standard means that a wide range of identity providers will work with GitLab. Unfortunately we aren't familiar with all of them so can only offer support configuring the [listed providers](#providers).
### I need additional information to configure my identity provider
Many SAML terms can vary between providers. It is possible that the information you are looking for is listed under another name.
For more information, start with your Identity Provider's documentation. Look for their options and examples to see how they configure SAML. This can provide hints on what you'll need to configure GitLab to work with these providers.
It can also help to look at our [more detailed docs for self-managed GitLab](../../../integration/saml.md).
SAML configuration for GitLab.com is mostly the same as for self-managed instances.
However, self-managed GitLab instances use a configuration file that supports more options as described in the external [OmniAuth SAML documentation](https://github.com/omniauth/omniauth-saml/).
Internally that uses the [`ruby-saml` library](https://github.com/onelogin/ruby-saml), so we sometimes check there to verify low level details of less commonly used options.
It can also help to compare the XML response from your provider with our [example XML used for internal testing](https://gitlab.com/gitlab-org/gitlab/blob/master/ee/spec/fixtures/saml/response.xml).
