API Security with Access Control: Best Practices for a Safer Backend

Hi there! I’m Maneshwar. Right now, I’m building LiveAPI, a first-of-its-kind tool that helps you automatically index API endpoints across all your repositories. LiveAPI makes it easier to discover, understand, and interact with APIs in large infrastructures.

APIs are the lifeline of modern applications, enabling systems to talk to each other and share data.

But without strong access control and secure configurations, APIs can become major attack vectors.

Here’s a focused breakdown on how to protect your APIs with proper access control and some essential security headers and configurations.

1. Throttle Requests

Prevent brute-force and DDoS attacks

Throttling restricts the number of requests a client can make in a defined time window. This is essential to stop:

• Brute-force login attempts where attackers guess credentials by trying many combinations rapidly.
• DDoS attacks that aim to overwhelm your backend with massive traffic.

In Go (Echo + Middleware):

e.Use(middleware.RateLimiter(middleware.NewRateLimiterMemoryStore(20))) // 20 reqs/sec per IP

Use more advanced strategies (e.g., token bucket) or tools like Nginx’s limit_req_zone, Cloudflare rate limiting, or AWS WAF for scalable throttling.

2. Use HTTPS

Encrypt everything in transit

Always serve your APIs over HTTPS to prevent eavesdropping and MITM (man-in-the-middle) attacks. Install a valid SSL/TLS certificate and redirect all HTTP traffic to HTTPS.

server {
    listen 80;
    server_name api.example.com;
    return 301 https://$server_name$request_uri;
}

Cipher Security:

• Use: TLS 1.2+, AES-GCM, ECDHE, ChaCha20
• Avoid: RC4, DES, TLS 1.0/1.1

Most modern web servers allow you to configure cipher suites explicitly.

3. Enforce HSTS

Block SSL Strip Attacks

SSL Strip attacks work by downgrading secure HTTPS connections to HTTP. Enabling HSTS (HTTP Strict Transport Security) forces browsers to only use HTTPS for your domain.

How to Enable:

Strict-Transport-Security: max-age=63072000; includeSubDomains; preload

This tells browsers to:

• Use HTTPS for future requests
• Include all subdomains
• Preload your domain into browser HSTS lists (optional, but safer)

4. Disable Directory Listings

Don’t expose your internals

Directory listings allow visitors to browse files if an index file isn’t found. If left enabled, attackers can:

• Discover sensitive files (e.g., backups, environment configs)
• Probe your deployment for exploits

Apache:

Options -Indexes

Nginx:

autoindex off;

This is a small but critical configuration for preventing unnecessary exposure.

5. Restrict Private APIs

Use IP allowlists

Private APIs (like internal dashboards, service-to-service endpoints, or CI/CD webhooks) should never be publicly accessible.

Restrict access by IP on your server, reverse proxy, or at the cloud firewall level.

Nginx Example:

location /internal-api/ {
    allow 192.168.0.0/24;
    deny all;
}

In cloud environments:

• Use Security Groups (AWS)
• Use Firewall Rules (GCP)
• Use NSGs (Azure)

Also, consider mutual TLS (mTLS) for highly sensitive internal APIs.

Bonus: Combine with Authentication & Authorization

Access control isn’t just IP or rate limiting. Combine with:

• OAuth2 / JWT tokens
• API Keys (for low-risk access)
• RBAC (Role-Based Access Control) to enforce what each user/system can do
• Scopes and Claims to control access granularity

Final Thoughts

Securing an API isn’t just about slapping on authentication. It’s about layered defenses:

• Limit exposure (IP restrict, HSTS, disable listings)
• Minimize brute-force surface (throttling)
• Encrypt everything (HTTPS with good ciphers)
• Add strict access control (mTLS, roles, scopes)

Security isn’t a one-time setup. Regularly audit, test, and improve.

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With LiveAPI, you can generate interactive API docs that allow users to search and execute endpoints directly from the browser.

If you’re tired of updating Swagger manually or syncing Postman collections, give it a shot.