Rediscovering an Unexpected Security Treasure

A few weeks ago, a discussion around a .NET security vulnerability sparked a deeper dive into the past. That journey led to an unexpected discovery: The Developer Highway Code, a security-focused book that had been sitting quietly in the background for years.

Published in 2006 by Microsoft UK, this book was designed as a practical guide to writing safer and more secure .NET applications. Despite its age, many of its ideas remain surprisingly relevant today.

What Is The Developer Highway Code?

Subtitled The Drive for Safer Coding, the book aims to educate developers on secure software engineering through clear guidance, structured checklists, and even a bit of humor. It covers a wide range of topics—from network configuration to database access—using the .NET Framework as its foundation.

One of its standout qualities is tone. Alongside serious security advice, the book includes lighthearted warnings and visual metaphors that make complex topics more approachable. While some jokes clearly reflect their era, they add character and make the content memorable.

Structure and Main Topics

The book is divided into two major sections:

  • Part One: Secure Engineering – principles, concepts, and platform features
  • Part Two: Checklists and Question Lists – practical steps to validate security at different layers

While early references to .NET Framework 1.1 feel dated, much of the material introduced in .NET 2.0 marked a significant step forward for secure development.

Infrastructure and Network Security Checklists

One of the most impressive aspects of the book is its detailed security checklists. For example, it emphasizes:

  • Ensuring the latest patches are installed
  • Subscribing to vendor security notifications
  • Blocking known vulnerable ports
  • Enabling ingress and egress filtering
  • Screening ICMP traffic
  • Securing router administration interfaces
  • Disabling unused services such as TFTP (Trivial File Transfer Protocol)

Even decades later, these recommendations still form the backbone of good network security hygiene.

Defending Against SQL Injection

The database security guidance feels especially timeless. The book strongly recommends:

  • Using stored procedures with parameters
  • Falling back to type-safe SQL parameters when stored procedures are not possible
  • Connecting to databases using least-privileged accounts

It’s striking how little these fundamentals have changed. Modern ORMs make these practices easier, but the underlying principles remain the same.

What Was New in .NET 2.0

At the time, .NET 2.0 introduced several major security improvements, including:

  • Programmable Access Control Lists (ACLs) via managed code
  • MachineKey configuration for encryption and authentication consistency
  • ClickOnce sandbox execution for Windows Forms applications
  • Code Access Security (CAS) for restricting permissions
  • ConnectionStringBuilder classes for safer connection handling
  • SecureString for protecting sensitive data in memory

Many of these features addressed problems that developers still face today—long before containers and modern sandboxing became mainstream.

Application-Level Security Practices

The book also outlines best practices for application and data validation:

  • Validating input using regular expressions
  • Using built-in ASP.NET validator controls
  • Never trusting user input
  • Avoiding dynamic SQL where possible
  • Validating all untrusted input within data access layers

Although the examples predate MVC and modern frameworks, the security mindset remains relevant.

Secure Class Design Guidelines

Several object-oriented design recommendations are highlighted, such as:

  • Using the most restrictive access modifiers possible
  • Sealing base classes not intended for inheritance
  • Keeping fields private and exposing them via properties
  • Making properties read-only unless write access is required
  • Using strong naming or security transparency where appropriate

Some of these ideas are debated today, but they offer valuable insight into how security concerns shaped earlier .NET design philosophies.

Communication Security: Then and Now

The book advocates for:

  • Transport-level encryption to protect secrets
  • IPSec for server-to-server communication
  • SSL for application-level encryption

While terminology has evolved—TLS has replaced SSL—the core message about encrypting data in transit is as important as ever.

A Valuable Trip Down Memory Lane

Revisiting The Developer Highway Code is both nostalgic and enlightening. It’s a reminder that while tools and terminology change, many security fundamentals stay the same.

Authored by Phil Winstanley, a technical evangelist at Microsoft UK, and Alex Mackman, a principal technologist at CM Group Limited, the book stands as a snapshot of .NET security thinking in the mid-2000s.

Even without an ISBN or modern availability, it remains a fascinating and valuable read for anyone interested in the evolution of secure software development.