Hi @Chery / Cherry,
I can help with some really high level explanations, to help you put yourself on the rails.
For further information, you might need to google, ask an expert or to go through the documentation in SAS and IT, that explain all of this in detail. Let me get myself started.
Every company needs a repository where all users, passwords, groups and other information are stored, and many resources, such as servers or PCs will be querying this repository in order to authenticate users or enforce certain policies. On Windows environments this is the Active Directory, and on Linux systems ou have OpenLDAP and others. LDAP is the protocol used for servers and PCs to connect to this repository.
PAM is a module on Linux that would allow Linux machines to use different authentication methods to authenticate.
SSSD is a service, that can be plugged into PAM, that allows the authentication to Active Directory or any LDAP server.
User IDs (UID) and Usergroup IDs (GID) are necessary on every system. The domain ones will be defined on one of those company repositories, such as AD or LDAP, and their scope can be as broad as the company is. The local ones are defined on the server or PCs, and their scope is just that server or PC.
How SAS 9.4 ( DI ) authenticates and SAS Viya authentication process? -- This is too broad, as there are different authentication mechanisms for every tier. Here I suggest you to review the documentation. In SAS 9.4 the main authentication mechanism is Host Authentication (which allows also to authenticate against AD or LDAP depending on configuration), but you have more methods, such as Web Authentication. In SAS Viya the main authentication is LDAP and OAuth, but you have many more.
How to integrate SSO to SAS 9.4 ( DI ) and SAS Viya? -- This is even broader, you are asking for how-to guides. You do need to refer to the SAS documentation. Single Sign On have different ways to be applied as well: NTLM, Kerberos, SAML, etc.
Looking at the nature of your questions, I would highly recommend you to get the support of a Subject Matter Expert. Perhaps it would be a good idea for you to contact your SAS representative or a SAS partner.
In any case, thanks a lot for your question, it is a good one, I am sure others will see themselves with similar questions, therefore it is a good opportunity to provide some initial guidance. Really appreciated.
I hope it can help you a bit. If you have more questions, please do not hesitate to share, we are here to help each other!
You too, stay healthy.
Best regards,
Juan
