How do I build role-based access for SSO users?

To build role-based access for SSO users, you generally want to treat the SSO provider as the identity source and your app as the authorization source.

1) Separate authentication from authorization

• Authentication: “Who is the user?” → handled by SSO/SAML/OIDC.
• Authorization: “What can they do?” → handled by your app, based on roles/permissions.

Even if the identity provider can send roles/groups, your app should still define what those roles mean.

2) Decide where roles come from

Common patterns:

A. Roles assigned in your app

• After SSO login, you match the user by email, subject, or directory ID.
• Your app stores a role like admin, editor, viewer.
• Best when your app needs its own permission model.

B. Roles/groups sent by the IdP

• The IdP includes group/role claims in the token/assertion.
• Your app maps those claims to internal roles.
• Good for central IT-managed access control.

C. Hybrid approach

• IdP provides coarse groups like Finance, HR, Engineering.
• Your app converts those into app-specific permissions.

3) Use stable identifiers, not just email

For SSO users, email can change. Prefer:

• sub claim in OIDC
• SAML NameID or a persistent identifier
• Directory object ID / immutable user ID

Store a mapping like:

• external identity ID → internal user record
• internal user record → roles/permissions

4) Model access in your app

A simple model:

• User
• Role
• Permission
• UserRole
• RolePermission

Example:

• admin → manage_users, view_reports, edit_settings
• viewer → view_reports

For simpler apps, roles alone may be enough.

5) Provision users on first login

When a user logs in via SSO:

1. Validate the SSO response/token.
2. Look up user by immutable external ID.
3. If new, create a local user record.
4. Assign a default role.
5. Apply mapped roles/groups from the IdP if available.

This is often called just-in-time provisioning.

6) Handle group/role mapping

If the IdP sends groups like:

• app-admins
• app-editors

Map them to internal roles:

• app-admins → admin
• app-editors → editor

Keep this mapping configurable so you don’t hardcode IdP-specific logic.

7) Enforce authorization everywhere

Check roles/permissions:

• in the frontend for UI visibility
• in the backend for actual security enforcement
• at the API endpoint or service layer

Never rely only on frontend checks.

8) Plan for user lifecycle

You need rules for:

• user removed from IdP group
• user disabled in IdP
• role changes
• account deprovisioning

Typically, on every login or token refresh:

• re-sync roles/groups
• revoke access if no longer authorized

9) Log and audit

Track:

• login events
• role assignments
• permission changes
• denied access attempts

This helps with security reviews and troubleshooting.

10) Recommended implementation pattern

A common robust setup:

1. SSO login via OIDC or SAML
2. App receives identity claims
3. App finds/creates local user
4. App syncs external groups to internal roles
5. App authorizes requests using internal permissions
6. Periodic or login-time revalidation

Example flow

If a user logs in with SSO and the token contains:

• sub = abc123
• email = jane@company.com
• groups = ["finance-team", "app-admins"]

Your app might:

• create or update user jane
• map app-admins to admin
• map finance-team to billing_viewer
• issue your own session/JWT with internal roles included

Best practices

• Use least privilege by default.
• Prefer group-based assignment over manual per-user assignment at scale.
• Keep a local authorization layer even if the IdP sends roles.
• Use immutable IDs for identity matching.
• Make mappings configurable and auditable.

If you want, I can also give you:

1. a database schema for this,
2. an OIDC/SAML example flow, or
3. sample code in Node, Python, or Java.