OAuth2 Rate Limiting — Protecting Authorization Endpoints from Abuse and DoS Attacks

In this tutorial, you will learn about OAuth2 Rate Limiting. We cover key concepts, practical examples, and best practices to help you master this topic.

OAuth2 rate limiting protects authorization server endpoints from abuse, brute force attacks, and accidental overload by enforcing per-client and global request limits on token issuance, authorization, and introspection.

What You'll Learn

• Rate limiting strategies for auth endpoints
• Per-client vs global rate limits
• Token endpoint brute force protection
• Introspection endpoint Caching
• Rate limit response headers

Why It Matters

Authorization endpoints are attractive targets for attackers. A brute force attack on the token endpoint can guess client secrets. A flood of introspection requests can overwhelm the auth server. DodaTech enforces 100 req/s per client and 5000 req/s globally with progressive rate limiting.

flowchart TD
    A["Request to Auth Server"] --> B{"Authenticated
client?"}
    B -->|"Yes"| C["Apply per-client rate limit
(100 req/s)"]
    B -->|"No"| D["Apply anonymous rate limit
(10 req/s)"]
    C --> E{"Under limit?"}
    D --> E
    E -->|"Yes"| F["Process request"]
    E -->|"No"| G["Apply global rate limit"]
    G --> H{"Under global
limit?"}
    H -->|"Yes"| F
    H -->|"No"| I["429 Too Many Requests
Retry-After header"]

What's Next

Implement rate limiting in your {{< ilink "OAuth" "OAuth2 Authorization Server" }} and review {{< ilink "OAuth" "OAuth2 Security Best Practices" }}.