Azure Event Hubs Developers Guide

Security for Azure Event Hubs

Securing your Azure Event Hubs is paramount to protect your data and ensure reliable message processing. Event Hubs offers a comprehensive set of security features, including authentication, authorization, and network isolation.

Authentication and Authorization

Azure Event Hubs supports multiple authentication mechanisms to control access to your event hubs. The primary methods are:

1. Azure Active Directory (Azure AD) Authentication

This is the recommended approach for securing Event Hubs. It leverages Azure AD identities (users, groups, service principals, or managed identities) to grant access. You can assign roles to these identities at various scopes (namespace, event hub, consumer group).

• Roles: Common roles include Azure Event Hubs Owner, Azure Event Hubs Data Sender, and Azure Event Hubs Data Receiver.
• Service Principals: Ideal for applications and services that need to send or receive data without user intervention.
• Managed Identities: A secure way for Azure resources (like Azure Functions or VMs) to authenticate to Event Hubs without managing credentials.

2. Shared Access Signatures (SAS)

SAS provides a way to delegate access to Event Hubs using tokens. You create SAS keys with specific permissions (listen, send, manage) and expiry times. While simpler to implement initially, managing and rotating SAS keys can be more complex than Azure AD.

Example of creating a SAS token (conceptual):

// This is a conceptual example and not actual code.
// Actual implementation depends on the SDK.

const namespace = "your-event-hubs-namespace.servicebus.windows.net";
const entityPath = "your-event-hub-name";
const policyName = "RootManageSharedAccessKey"; // Or a custom policy
const accessKey = "YOUR_PRIMARY_OR_SECONDARY_KEY"; // From the portal

// Generate token using a library or SDK function
const sasToken = generateSasToken(namespace, entityPath, policyName, accessKey);

// Use the SAS token in connection string or directly
const connectionString = `Endpoint=sb://${namespace};SharedAccessKeyName=${policyName};SharedAccessKey=${accessKey};EntityPath=${entityPath}`;

Network Security

Control network access to your Event Hubs namespace for enhanced security:

• Firewalls: Configure IP filters to allow traffic only from trusted IP addresses or ranges.
• Virtual Network (VNet) Service Endpoints: Secure your Event Hubs namespace by restricting access to a specific virtual network. This allows services within the VNet to connect to Event Hubs using private IP addresses.
• Private Endpoints: Provide a secure and private connection from your VNet to Event Hubs using Azure Private Link. This removes the need for public internet access.

Data Encryption

Azure Event Hubs encrypts data at rest and in transit by default.

• In Transit: All communication with Event Hubs uses TLS/SSL, ensuring data is encrypted while moving between clients and the service.
• At Rest: Data stored in Event Hubs is automatically encrypted using AES-256. You can also optionally use Azure Key Vault-managed keys for more granular control over encryption.

Best Practices for Security

Follow these best practices to maintain a secure Event Hubs deployment:

• Prefer Azure AD authentication over SAS tokens whenever possible.
• Grant the least privilege necessary to users and applications.
• Regularly rotate secrets and keys if using SAS.
• Implement network restrictions using firewalls, VNet service endpoints, or private endpoints.
• Use Managed Identities for Azure resources to authenticate without storing credentials.
• Enable diagnostic logging to monitor access and detect suspicious activities.

By implementing these security measures, you can build robust and secure event streaming solutions with Azure Event Hubs.