Security Best Practices

Always verify signatures — Never process webhooks without validating the signature.

Use constant-time comparison — Prevents timing attacks that could leak information about the expected signature.

Check timestamp freshness — Reject webhooks with timestamps older than 5 minutes to prevent replay attacks:

import time

current_time = int(time.time())
webhook_time = int(timestamp)

if abs(current_time - webhook_time) > 300:  # 5 minutes
    reject_webhook()

Store your secret securely — Use environment variables or a secrets manager; never commit secrets to version control.

Respond quickly — Return a 2xx response within 30 seconds; process the webhook payload asynchronously if needed.

Use HTTPS — Always use HTTPS for your webhook endpoint to ensure transport-level encryption.

Log failed verifications — Monitor for repeated signature failures which may indicate an attack attempt.