🔐Azure Front Door Custom Cipher Suite

 

Introduction

As cybersecurity threats grow in sophistication, organizations are increasingly required to tailor their TLS (Transport Layer Security) configurations to meet strict security standards, performance objectives, and compliance frameworks.

With the April 2025 GA (General Availability) release, Azure Front Door (AFD) Standard and Premium now support Custom Cipher Suite Configuration, empowering enterprises to define exactly how encrypted traffic is negotiated at the edge.

This long-awaited feature enhances control, compliance, and performance, making Azure Front Door an even more robust choice for secure global web application delivery.

Why This Matters

Before this release, Azure Front Door enforced a default cipher suite that was managed entirely by Microsoft. While secure and updated regularly, it lacked customization, which presented challenges in:

• Regulatory compliance (e.g., PCI DSS, NIST, FedRAMP)
• Compatibility with legacy or high-security client environments
• Security posture hardening (removing weak ciphers like RSA or legacy TLS 1.0/1.1)

Now, organizations can define their own TLS cipher suite order using Azure Resource Manager (ARM), Bicep, or REST APIs, and enforce TLS versions like TLS 1.2 or 1.3 only.

What’s New – Feature Capabilities

Available in Azure Front Door Standard and Premium tiers

Supports:

• Custom TLS cipher suite ordering
• TLS version enforcement
• Strong cipher suite selection
• Disabling legacy algorithms (e.g., RC4, 3DES, SHA-1)

Cipher Suite Examples

Below is a sample secure cipher suite configuration supporting TLS 1.2 and 1.3, optimized for modern browsers and compliance:

Bicep Deployment Template

Compliance Use Cases

Organizations in regulated industries (finance, healthcare, defense) can now meet specific regulatory controls such as:

• PCI DSS 4.0
• Disallow weak ciphers and enforce TLS 1.2+
• NIST 800-52r2
• Require only FIPS-validated cipher suites
• FedRAMP High
• Eliminate support for TLS 1.0/1.1 and insecure algorithms

This level of customization also enables regional compliance such as:

• IRAP (Australia)
• ENS (Spain)
• BSI (Germany)

Monitoring & Validation

You can validate your configuration using:

• SSL Labs test
• Azure Front Door diagnostic logs
• Azure Monitor metrics
• Client-side curl/wget with verbose TLS information

Microsoft Documentation