Configuring identity-based access for Azure Files allows you to replace Shared Access Keys with specific identity permissions for Server Message Block (SMB) access. This integration supports three identity sources: On-premises Active Directory Domain Services (AD DS), Azure Active Directory Domain …Configuring identity-based access for Azure Files allows you to replace Shared Access Keys with specific identity permissions for Server Message Block (SMB) access. This integration supports three identity sources: On-premises Active Directory Domain Services (AD DS), Azure Active Directory Domain Services (Azure AD DS), and Azure Active Directory Kerberos for hybrid identities.
The configuration process relies on a two-layer permission model. First, you must enable the chosen identity source on the storage account and join the storage account to the domain. Once enabled, you configure Share-Level Permissions using Azure Role-Based Access Control (RBAC). You must assign specific RBAC roles—such as 'Storage File Data SMB Share Reader' (read-only), 'Contributor' (read/write), or 'Elevated Contributor' (allows changing permissions)—to the Azure AD users or groups that require access. Users cannot access the share without one of these roles.
Second, you rely on Directory/File-Level Permissions. While RBAC controls entry to the share, standard Windows Access Control Lists (ACLs) control granular access to files and folders within it. You configure these ACLs using Windows File Explorer or icacls by initially mounting the share with the storage account key (acting as a superuser). When a user accesses the file share, Azure Files enforces both the share-level RBAC role and the file-level ACLs. If there is a conflict, the most restrictive permission applies. This setup ensures secure, audited access management suitable for enterprise environments.
Configure Identity-Based Access for Azure Files: AZ-104 Guide
Introduction In the Azure Administrator (AZ-104) curriculum, implementing and managing storage is a substantial domain. A critical component of this is securing Azure File Shares not just with broad storage account keys, but with granular, identity-based authentication. Accessing Azure Files via Server Message Block (SMB) using identity-based authentication allows you to enforce permissions based on user roles and group memberships, mirroring the security models found in traditional on-premises file servers.
Why is it Important? By default, Azure Storage accounts use 'Access Keys' for authentication. This provides full administrator access to the storage account, which poses a significant security risk if keys are leaked. Identity-based access addresses this by: 1. Granular Security: Allowing specific users different levels of access (Read vs. Write). 2. Auditability: Tracking who accessed what file, rather than just seeing generic access via a key. 3. Migration Compatibility: Enabling 'Lift and Shift' scenarios where on-premises ACLs (Access Control Lists) are preserved when moving data to the cloud.
What is Identity-Based Access for Azure Files? It is a feature that allows Azure File shares to authenticate users against an identity provider via the SMB protocol. Azure Files supports three main methods for this integration: 1. On-premises Active Directory Domain Services (AD DS): The storage account is domain-joined to your on-prem AD. Identities must be synced to Microsoft Entra ID (formerly Azure AD). 2. Azure Active Directory Domain Services (Azure AD DS): Access via a managed domain service in Azure. 3. Azure Active Directory Kerberos for Hybrid Identities: Allows Azure AD to issue Kerberos tickets for accessing file shares.
How it Works: The Two-Layer Permission Model To successfully configure access, you must understand that improved security relies on two distinct layers of permissions:
Layer 1: Share-Level Permissions (RBAC) Before a user can even touch the files, they must have permission to mount the share. This is handled by Azure Role-Based Access Control (RBAC). You assign specific Azure built-in roles to the user or group at the Share scope. Key Roles needed for the exam: - Storage File Data SMB Share Reader: Read access. - Storage File Data SMB Share Contributor: Read, write, and delete access. - Storage File Data SMB Share Elevated Contributor: Read, write, delete, and modify NTFS permissions (ACLs).
Layer 2: Directory/File-Level Permissions (Windows ACLs) Once the RBAC layer grants access to the 'door' (the share), Windows ACLs control access to the 'rooms' (directories and files). These are standard NTFS permissions configured using Windows File Explorer or the icacls command. You must mount the share using the Storage Account Key (Super User) initially to configure these permissions.
How to Configure it (The Workflow) 1. Enable the specific Identity source (e.g., AD DS) on the Storage Account configuration blade. 2. Join the Storage Account to the domain (requires a script depending on the method). 3. Assign Share-Level permissions (Azure RBAC) to the synced identities. 4. Mount the share using the Storage Account Key to initialize setup. 5. Configure Directory/File-Level permissions (ACLs) for the specific AD users/groups.
Exam Tips: Answering Questions on Configure identity-based access for Azure Files When facing AZ-104 scenario questions, follow this logic checklist:
1. The 'Access Denied' on Mount Scenario: If a user cannot mount the drive at all, the issue is likely Share-Level (RBAC). Check if the user has the Storage File Data SMB Share [Role] assigned. Note that standard roles like 'Owner' or 'Storage Blob Data Contributor' DO NOT grant SMB access.
2. The 'Read-Only' vs 'Write' Scenario: If a user can mount the drive but cannot edit a file, check the File-Level (NTFS/ACL) permissions. However, also verify they aren't restricted by having only the Reader RBAC role. Remember: The 'Most Restrictive' permission always wins between RBAC and ACLs.
3. Pre-requisites Check: If the question involves on-premises AD DS, look for the requirement that the identity must be synced to Microsoft Entra ID (Azure AD).
4. Network Connectivity: Ensure port 445 (SMB) is open and not blocked by the ISP or firewall, and that the client machine has network visibility to the Domain Controller (for ticket authentication).
5. Key vs. Identity: If a scenario requires 'granular' access or auditing individual users, the answer involves identity-based access. If the scenario allows for simple, administrative, full access for an application, a Shared Access Signature (SAS) or Storage Key might be the distractor, but Identity is the answer for user-specific security.