第 50 章 Enabling authentication using AD User Principal Names in IdM
As an Identity Management (IdM) administrator, you can allow AD users to use alternative User Principal Names (UPNs) to access resources in the IdM domain. A UPN is an alternative user login that AD users authenticate with in the format of user_name@KERBEROS-REALM. As an AD administrator, you can set alternative values for both user_name and KERBEROS-REALM, since you can configure both additional Kerberos aliases and UPN suffixes in an AD forest.
For example, if a company uses the Kerberos realm AD.EXAMPLE.COM, the default UPN for a user is user@ad.example.com. To allow your users to log in using their email addresses, for example user@example.com, you can configure EXAMPLE.COM as an alternative UPN in AD. Alternative UPNs (also known as enterprise UPNs) are especially convenient if your company has recently experienced a merge and you want to provide your users with a unified logon namespace.
UPN suffixes are only visible for IdM when defined in the AD forest root. As an AD administrator, you can define UPNs with the Active Directory Domain and Trust utility or the PowerShell command line tool.
To configure UPN suffixes for users, Red Hat recommends to use tools that perform error validation, such as the Active Directory Domain and Trust utility.
Red Hat recommends against configuring UPNs through low-level modifications, such as using ldapmodify commands to set the userPrincipalName attribute for users, because Active Directory does not validate those operations.
After you define a new UPN on the AD side, run the ipa trust-fetch-domains command on an IdM server to retrieve the updated UPNs. See Ensuring that AD UPNs are up-to-date in IdM.
IdM stores the UPN suffixes for a domain in the multi-value attribute ipaNTAdditionalSuffixes of the subtree cn=trusted_domain_name,cn=ad,cn=trusts,dc=idm,dc=example,dc=com.