Mastering Conditional Access & SSO with Azure AD

In today's rapidly evolving digital landscape, securing access to applications is paramount. Azure Active Directory (Azure AD) provides robust solutions to achieve this, with Conditional Access and Single Sign-On (SSO) being cornerstones of modern identity and access management. This post dives deep into how these two powerful features work together to enhance security and streamline user experience.

What are Conditional Access and SSO?

Single Sign-On (SSO)

Single Sign-On (SSO) allows users to authenticate once and gain access to multiple applications without needing to re-enter their credentials. This significantly improves user productivity and reduces password fatigue.

Conditional Access

Azure AD Conditional Access is a powerful tool that acts as your cloud-based policy engine for access control. It allows you to enforce granular access policies based on specific conditions, such as user location, device state, application, and real-time risk detection. Conditional Access policies are deployed in the cloud and enforce your access policies across all your cloud applications.

The Synergy: How They Work Together

While SSO provides convenience, Conditional Access elevates it by adding a crucial layer of security. Instead of a blanket grant of access after the initial authentication, Conditional Access policies evaluate each access request in real-time. This means:

• Contextual Security: Access can be granted, denied, or require additional controls (like Multi-Factor Authentication) based on the context of the access request.
• Risk-Based Access: If a user's sign-in behavior appears risky (e.g., impossible travel, unfamiliar IP address), Conditional Access can enforce stronger controls even if SSO has already occurred.
• Device Compliance: You can ensure that only devices meeting your organization's security standards (e.g., compliant, hybrid joined) can access sensitive applications, even through SSO.

Key Components of a Conditional Access Policy

When configuring a Conditional Access policy, you define:

• Assignments: Who the policy applies to (users, groups).
• Target Resources: Which cloud apps or actions the policy applies to.
• Conditions: The specific circumstances under which the policy is enforced. This can include:
  • User risk: Based on Azure AD Identity Protection.
  • Sign-in risk: Based on Azure AD Identity Protection.
  • Device platforms: Windows, macOS, iOS, Android.
  • Locations: Trusted or untrusted IP address ranges.
  • Client applications: Browser, mobile apps, desktop clients.
  • Device state: Compliant, Hybrid Azure AD joined.
• Access Controls: The actions to take when conditions are met.
  • Grant: Allow access, require MFA, require device to be marked as compliant, require Hybrid Azure AD join, require approved client app, require app protection policy.
  • Block: Deny access.
  • Session controls: Limit sign-in frequency, control app in the cloud.

Example Scenario: Secure Access to a SaaS Application

Let's consider securing a critical SaaS application like Salesforce using Azure AD SSO and Conditional Access:

1. Configure SSO: Integrate Salesforce with Azure AD for SAML-based SSO. Users can now access Salesforce directly via the My Apps portal or by navigating to Salesforce.
2. Create a Conditional Access Policy:
   • Assignments: All users.
   • Target Resources: Salesforce application.
   • Conditions:
     • Locations: Require trusted locations (your corporate network IPs) for access without MFA.
     • Device Platforms: Allow access only from Windows and macOS.
     • Client Applications: Allow access from browsers.
   • Access Controls:
     • Grant: Require Multi-Factor Authentication for access from untrusted locations, from any device platform, or when accessing via mobile apps.

With this policy, a user signing in from their corporate office on a corporate laptop will have a seamless SSO experience. However, if they attempt to access Salesforce from a coffee shop or from their personal mobile device, they will be prompted for MFA, significantly reducing the risk of unauthorized access.

# Example Azure CLI snippet for managing Conditional Access (conceptual)
az ad conditional-access policy create --name "Secure SaaS App Access" \
  --conditions '{
    "locations": {"includeLocations": ["all"]},
    "clientAppTypes": ["all"],
    "platforms": {"includePlatforms": ["windows", "macos"]}
  }' \
  --grantControls '{
    "operator": "OR",
    "builtInControls": ["mfa"],
    "customControls": [],
    "termsOfUse": []
  }' \
  --applications '{"includeApplications": ["salesforce-app-id"]}' \
  --state "enabled"

Best Practices for Implementation

• Start with a Report-Only Mode: Before enforcing policies, use the "Report-only" mode to understand the impact without disrupting users.
• Define Trusted Locations: Clearly define your corporate IP ranges as trusted locations.
• Leverage Identity Protection: Integrate Azure AD Identity Protection for advanced user and sign-in risk detection.
• Segment Access: Create specific policies for critical applications and sensitive data.
• Regularly Review Policies: As your organization's needs change, ensure your Conditional Access policies are up-to-date.

Conclusion

Azure AD Conditional Access and SSO are a formidable pairing for securing your cloud environment. By combining the convenience of SSO with the granular control of Conditional Access, you can build a robust security posture that adapts to the dynamic nature of modern work. Implementing these features thoughtfully will protect your organization from evolving threats while empowering your users.

"Security is not a product, but a process." - Unknown