The original title is "Webhook Security Best Practices: HMAC, Replay Attacks & Encryption"

Short summary

This guide covers four layers of webhook security: transport encryption, HMAC-SHA256 signature verification with constant-time comparison, replay-attack prevention via 5-minute timestamp windows, and payload privacy. Includes working Node.js examples and a practical checklist based on verified standards from Stripe, GitHub, and Svix. Addresses overlooked attack vectors including DNS rebinding, timing attacks, and SSRF that standard tutorials miss.

• •Implement four security layers: HTTPS/mTLS, HMAC-SHA256 with constant-time comparison, timestamp-based replay detection (5-min tolerance), and secrets management
• •Real threats include timing attacks, DNS rebinding SSRF, and duplicate delivery; the 5-minute tolerance window is the industry standard from Stripe and Svix
• •Working code examples and a practical 8-point checklist help teams avoid common mistakes like regex-based validation and naive string comparison

Generated with AI, which can make mistakes.