Access Cloud Resources Across Tenants Without Secrets: A Game-Changer for Multi-Tenant Security

Managing access across multiple cloud tenants has traditionally been a challenge for IT admins and developers. Securely connecting applications and services between tenants often requires shared secrets, certificates, or keys—solutions that can be cumbersome to manage and introduce security risks if mishandled.

Enter Microsoft’s latest innovation: Access Cloud Resources Across Tenants Without Secrets. This new feature simplifies multi-tenant resource access while eliminating the need for shared secrets, offering a more secure, efficient, and scalable solution.

What Is This New Feature?

This capability, announced in the Microsoft Identity Dev Blog, allows you to connect cloud resources and services across different Azure Active Directory (Entra ID) tenants without relying on secrets or certificates for authentication.

Instead of secrets, the feature leverages federated identity credentials in Entra ID. These credentials allow workloads, like applications or automation scripts, to authenticate directly using their managed identity—removing the need for long-lived credentials like passwords, API keys, or client secrets.

Why Is This a Big Deal?

1. Eliminates Secrets Management
   Traditional cross-tenant access often relies on secrets or certificates, which need regular rotation and careful storage to prevent exposure. Federated identity credentials completely remove this dependency, reducing operational overhead and the risk of credential leakage.

2. Enhances Security
   By eliminating static credentials, this feature reduces the attack surface. Managed identities are inherently more secure because they are automatically managed by Azure, and their authentication lifecycle is tightly controlled.

3. Simplifies Automation and Scaling
   Federated identity credentials make it easier to set up cross-tenant automation. Developers no longer need to worry about embedding secrets in code or managing certificates for service-to-service communication.

4. Streamlines Multi-Tenant Operations
   Organizations operating in a multi-tenant environment (e.g., large enterprises, service providers, or SaaS vendors) can now enable secure access between tenants without creating and maintaining additional infrastructure for credential management.

Key Scenarios

This new feature is particularly useful in the following scenarios:

1. Cross-Tenant Automation

Imagine a scenario where a service in Tenant A needs to periodically access resources in Tenant B, such as fetching logs or triggering updates. With federated identity credentials, this can be done seamlessly without storing secrets in Tenant A or managing a key vault.

2. Third-Party Application Access

SaaS applications often require access to customer tenants for specific operations (e.g., managing Azure resources, accessing logs, or processing data). Federated identity credentials allow SaaS vendors to securely authenticate their applications to customer tenants without requiring customers to manage and share secrets.

3. Shared Resource Management

Enterprises with multiple Azure tenants can enable internal applications to access resources across tenants securely and easily—for example, a central monitoring app accessing diagnostic logs from multiple tenants.

How Does It Work?

At its core, the feature uses federated identity credentials, which work as follows:

1. Create a Federated Identity Credential
   In the Entra ID tenant where your application resides, create a federated identity credential and associate it with the application’s managed identity.

2. Grant Permissions Across Tenants
   In the target tenant, assign the necessary permissions to the application. For example, if the app needs to read from a storage account, grant the corresponding RBAC role in that tenant.

3. Authenticate Without Secrets
   The application uses its managed identity to request tokens for the target tenant. Azure automatically handles the authentication process without requiring shared secrets or certificates.

How to Get Started

To begin using this feature, follow these steps:

1. Set Up Federated Identity Credentials
   Use the Azure portal, CLI, or PowerShell to create federated identity credentials for your application.

2. Configure Role Assignments
   In the target tenant, configure the appropriate role assignments for the application, ensuring it has the necessary permissions to perform its tasks.

3. Update Your Application Code
   Modify your application to authenticate using its managed identity. Azure SDKs make this straightforward by abstracting the authentication process.

4. Test and Monitor
   Test the configuration and monitor access to ensure the application is functioning as expected without introducing security risks.

Best Practices

• Adopt the Principle of Least Privilege: Assign the minimum necessary permissions to your application in the target tenant to reduce potential risks.
• Monitor Access: Use Azure Monitor and Entra ID logs to track cross-tenant access and detect anomalies.
• Combine with Conditional Access: Strengthen security by enforcing conditional access policies for federated identity credentials.

Conclusion

The ability to access cloud resources across tenants without secrets marks a significant step forward in simplifying and securing multi-tenant environments. By eliminating the need for shared secrets, this feature reduces operational complexity, improves security, and empowers developers to build scalable solutions in a cloud-first world.

Whether you’re managing multiple Azure tenants, building SaaS applications, or automating cross-tenant workflows, this capability is a must-explore. Dive into the official documentation to learn more and start implementing it in your environment today.