Providing Access to Azure Files

Primary service:

• Azure Files

Identity-based authentication allows Azure Files to integrate with directory services such as:

• Microsoft Entra ID
• Active Directory Domain Services (AD DS)
• Microsoft Entra Domain Services

Instead of using:

• Storage account keys
• SAS tokens
• This provides enterprise-grade access control.

Official documentation:

1️⃣ Why Use Identity-Based Authentication?#

Traditional methods (Access Keys / SAS):

❌ Full account-level access ❌ Hard to audit ❌ Not user-specific ❌ Poor least-privilege enforcement

Identity-based authentication provides:

✔ Per-user authentication ✔ Kerberos support ✔ RBAC enforcement ✔ Familiar Windows admin model ✔ Integration with LDAP/Kerberos apps ✔ Auditability

2️⃣ What Identity-Based Authentication Controls#

Important distinction:

Identity-based authentication controls:

• ✔ Share-level access

It does NOT replace:

• ❗ File-level NTFS ACLs ❗ Directory-level permissions

You still must configure:

• Windows Access Control Lists (ACLs)

Think of it as:

• Layer 1: Share access (Azure RBAC) Layer 2: File/folder permissions (NTFS ACL)

3️⃣ Identity Options for Azure Files#

Azure Files supports three identity models:

🔹 1. Active Directory Domain Services (AD DS)#

• Traditional on-premises domain.

Best for:

• ✔ Hybrid environments ✔ Lift-and-shift scenarios ✔ Existing Windows infrastructure

Requires:

• Domain-joined storage account
• Service principal setup
• SPN configuration

Docs:

🔹 2. Microsoft Entra Domain Services#

• Managed domain service.

Best for:

• ✔ Cloud-first deployments ✔ No on-prem domain controllers ✔ Simplified domain management

Prerequisite:

• Entra Domain Services must already be deployed.

Docs:

🔹 3. Microsoft Entra Kerberos#

• Modern cloud-native approach.

Best for:

• ✔ Hybrid Azure AD-joined devices ✔ Cloud-first identity strategy

Requires:

• Entra ID application registration
• Kerberos ticket issuance
• Explicit permission grants

Docs:

4️⃣ Share-Level RBAC Roles#

When identity-based authentication is enabled, you manage access via:

• Azure RBAC roles.

Key built-in roles:

These apply at:

• File share scope
• Storage account scope
• Resource group scope

Docs:

5️⃣ How Authentication Flow Changes#

Without Identity-Based Auth#

Mount script uses:

• Storage account name
• Access key (as password)

Example concept:

• net use Z: \storageaccount.file.core.windows.net\share
• This uses root-level credentials.

With Identity-Based Auth#

Mount script:

• Uses domain credentials
• Uses Kerberos ticket
• No access key required

Security benefit:

• ✔ No shared secrets ✔ Identity-bound access ✔ Better auditing

6️⃣ Access Control Layers Explained#

🔹 Layer 1: Share-Level Authorization#

Controlled via:

• Azure RBAC

Determines:

• Can user connect to share?

🔹 Layer 2: File-Level Permissions#

Controlled via:

• NTFS ACLs

Determines:

• Can user read/write specific files?

Example:

• User may connect to share But denied access to specific folder

7️⃣ ACL (Access Control List) Concept#

An ACL defines:

• Users
• Groups
• Computer accounts
• Security principals

And their permissions:

• Read
• Write
• Modify
• Full Control

ACLs can be:

• ✔ Backed up ✔ Restored ✔ Managed via File Explorer

8️⃣ Demonstration Summary#

Steps shown:

• Open file share
• Click "Identity-based access"

Choose identity source:

• AD DS
• Entra Domain Services
• Entra Kerberos
• Enable configuration
• Assign RBAC roles
• Mount using identity instead of key

Key observation:

• Mount script no longer requires storage account key.

9️⃣ Security Architecture Comparison#

Enterprise best practice:

Disable storage key access Use Entra ID + RBAC

🔟 Hybrid Architecture Scenario#

Common enterprise pattern:

• On-Prem AD ↓ Azure AD Connect ↓ Microsoft Entra ID ↓ Azure Files (Kerberos auth)

This allows:

• ✔ Seamless authentication ✔ Same credentials ✔ Hybrid identity

11️⃣ Important Limitations#

⚠ Identity-based auth applies only to SMB (not NFS) ⚠ NFS uses network-based controls ⚠ Must configure NTFS permissions separately ⚠ Requires proper DNS resolution ⚠ Port 445 must be open

12️⃣ Common Exam Pitfalls#

🚩 Identity-based auth replaces NTFS → False 🚩 Access keys are more secure → False 🚩 RBAC controls file-level ACL → False 🚩 Identity-based works for SMB → True 🚩 Custom roles allowed → True

13️⃣ Enterprise Best Practice Design#

Secure Azure Files design:

✔ Identity-based authentication enabled ✔ Azure RBAC assigned at share level ✔ NTFS ACLs configured properly ✔ Storage account key access disabled ✔ Private endpoints enabled ✔ Monitoring + logging enabled

14️⃣ Deep Concept: Why This Matters#

Traditional file servers:

• Rely on Kerberos
• Use NTFS permissions
• Use domain groups

Azure Files identity-based auth allows:

• Lift-and-shift without redesigning access model.

It bridges:

• Cloud storage + legacy enterprise authentication.

15️⃣ When to Use Each Identity Type#

Final Summary#

Identity-based authentication for Azure Files:

• Replaces shared secrets with user-based auth
• Integrates with AD / Entra ID
• Enables RBAC share-level control
• Still requires NTFS ACL configuration
• Improves security, auditability, and governance
• It is the recommended enterprise-grade method for securing Azure file shares.

If you'd like next:

• 🏗 Full hybrid AD + Azure Files architecture diagram
• 🧠 AZ-104 scenario questions on Azure Files identity
• 🔐 Step-by-step AD DS integration deep dive
• 📊 Security comparison: SAS vs Identity vs Keys
• 🛡 Zero-trust file share access design
• Tell me your goal (exam prep, architecture mastery, or enterprise deployment).