To use SAML single sign-on (SSO) for authentication to GitHub Enterprise Server, you must configure both your external SAML identity provider (IdP) and your GitHub Enterprise Server instance. In a SAML configuration, GitHub Enterprise Server functions as a SAML service provider (SP). For more information about authentication for your enterprise, see "
About identity and access management
."
GitHub Enterprise Server provides integration according to the SAML 2.0 specification. For more information, see the
SAML Wiki
on the OASIS website.
You must enter unique values from your SAML IdP when configuring SAML SSO for GitHub Enterprise Server, and you must also enter unique values from GitHub Enterprise Server on your IdP. For more information about authentication for
The SP metadata for your GitHub Enterprise Server instance is available at
http(s)://HOSTNAME/saml/metadata
, where
HOSTNAME
is the hostname for your instance. GitHub Enterprise Server uses the
urn:oasis:names:tc:SAML:2.0:bindings:HTTP-POST
binding.
| Value
| Other names
| Description
| Example
|
|---|
| SP Entity ID
| SP URL, audience restriction
| Your top-level URL for GitHub Enterprise Server
| http(s)://HOSTNAME
|
| SP Assertion Consumer Service (ACS) URL
| Reply, recipient, or destination URL
| URL where IdP sends SAML responses
| http(s)://HOSTNAME/saml/consume
|
| SP Single Sign-On (SSO) URL
| | URL where IdP begins SSO
| http(s)://HOSTNAME/sso
|
The following SAML attributes are available for GitHub Enterprise Server. You can change the attribute names in the Management Console, with the exception of the
administrator
attribute. For more information, see "
Administering your instance from the web UI
."
| Name
| Required
| Description
|
|---|
NameID
| | A persistent user identifier. Any persistent name identifier format may be used. GitHub Enterprise Server will normalize the
NameID
element to use as a username unless one of the alternative assertions is provided. For more information, see "
Username considerations for external authentication
."
Note:
It's important to use a human-readable, persistent identifier. Using a transient identifier format like
urn:oasis:names:tc:SAML:2.0:nameid-format:transient
will result in re-linking of accounts on every sign-in, which can be detrimental to authorization management.
|
SessionNotOnOrAfter
| | The date that GitHub Enterprise Server invalidates the associated session. After invalidation, the person must authenticate once again to access your GitHub Enterprise Server instance. For more information, see "
Session duration and timeout
."
|
administrator
| | When the value is
true
, GitHub Enterprise Server will automatically promote the user to be a site administrator. Setting this attribute to anything but
true
will result in demotion, as long as the value is not blank. Omitting this attribute or leaving the value blank will not change the role of the user.
|
username
| | The username for your GitHub Enterprise Server instance.
|
full_name
| | The full name of the user to display on the user's profile page.
|
emails
| | The email addresses for the user. You can specify more than one address. If you sync license usage between GitHub Enterprise Server and GitHub Enterprise Cloud, GitHub Connect uses
emails
to identify unique users across products. For more information, see "
Syncing license usage between GitHub Enterprise Server and GitHub Enterprise Cloud
."
|
public_keys
| | The public SSH keys for the user. You can specify more than one key.
|
gpg_keys
| | The GPG keys for the user. You can specify more than one key.
|
To specify more than one value for an attribute, use multiple
<saml2:AttributeValue>
elements.
<
saml2:Attribute
FriendlyName
=
"public_keys"
Name
=
"urn:oid:1.2.840.113549.1.1.1"
NameFormat
=
"urn:oasis:names:tc:SAML:2.0:attrname-format:uri"
>
<
saml2:AttributeValue
>
ssh-rsa LONG KEY
</
saml2:AttributeValue
>
<
saml2:AttributeValue
>
ssh-rsa LONG KEY 2
</
saml2:AttributeValue
>
</
saml2:Attribute
>
GitHub Enterprise Server requires that the response message from your IdP fulfill the following requirements.
-
Your IdP must provide the
<Destination>
element on the root response document and match the ACS URL only when the root response document is signed. If your IdP signs the assertion, GitHub Enterprise Server will ignore the assertion.
-
Your IdP must always provide the
<Audience>
element as part of the
<AudienceRestriction>
element. The value must match your
EntityId
for GitHub Enterprise Server. This value is the URL where you access your GitHub Enterprise Server instance, such as
http(s)://HOSTNAME
.
-
Your IdP must protect each assertion in the response with a digital signature. You can accomplish this by signing each individual
<Assertion>
element or by signing the
<Response>
element.
-
Your IdP must provide a
<NameID>
element as part of the
<Subject>
element. You may use any persistent name identifier format.
-
Your IdP must include the
Recipient
attribute, which must be set to the ACS URL. The following example demonstrates the attribute.
<
samlp:Response
...
>
<
saml:Assertion
...
>
<
saml:Subject
>
<
saml:NameID
...
>
...
</
saml:NameID
>
<
saml:SubjectConfirmation
...
>
<
saml:SubjectConfirmationData
Recipient
=
"https://HOSTNAME/saml/consume"
...
/>
</
saml:SubjectConfirmation
>
</
saml:Subject
>
<
saml:AttributeStatement
>
<
saml:Attribute
FriendlyName
=
"USERNAME-ATTRIBUTE"
...
>
<
saml:AttributeValue
>
monalisa
</
saml:AttributeValue
>
</
saml:Attribute
>
</
saml:AttributeStatement
>
</
saml:Assertion
>
</
samlp:Response
>
To prevent a person from authenticating with your IdP and staying authorized indefinitely, GitHub Enterprise Server periodically invalidates the session for each user account with access to your GitHub Enterprise Server instance. After invalidation, the person must authenticate with your IdP once again.
By default, if your IdP does not assert a value for the
SessionNotOnOrAfter
attribute, GitHub Enterprise Server invalidates a session one week after successful authentication with your IdP.
GitHub Enterprise Server will support a customized session duration if your IdP provides the option to configure a
SessionNotOnOrAfter
attribute and value, and if this attribute is included in SAML responses. If your IdP does not allow a
SessionNotOnOrAfter
attribute, a site administrator can configure a custom SAML session timeout for all users on your instance by using the
ghe-config saml.default-session-expiration [seconds]
command in the administrative shell.
If you define a customized session duration value less than 24 hours, GitHub Enterprise Server may prompt people to authenticate every time GitHub Enterprise Server initiates a redirect.
Regardless of the authentication method used on your instance, GitHub Enterprise Server will terminate a user session after two weeks of continuous inactivity.
Notes
:
- For Microsoft Entra ID (previously known as Azure AD), the configurable lifetime policy for SAML tokens does not control session timeout for GitHub Enterprise Server.
- Okta does not currently send the
SessionNotOnOrAfter
attribute during SAML authentication with GitHub Enterprise Server. For more information, contact Okta.
