webhook-authentication-security

To verify inbound webhook payloads, capture the raw request body and validate the HMAC-SHA-256 cryptographic signature against the incoming payload. This ensures authenticity and prevents tampering with your application's incoming webhooks.

Replay attacks on incoming webhooks are prevented using timestamp validation. By checking the delivery timestamp against a current time window, you ensure that expired or delayed webhook payloads are rejected before processing.

Sign outgoing webhook deliveries by generating an HMAC signature using per-endpoint secrets and delivery headers. Implementing a secret rotation strategy minimizes downtime while guaranteeing that customer endpoints receive trusted events.

Protect customer webhook endpoints from SSRF vulnerabilities by applying strict URL validation and endpoint validation rules. This guards against misconfigurations and blocks outbound webhook deliveries from targeting private networks.

Yes, this approach is designed for SaaS applications requiring trusted integrations with third-party services and customer endpoints. It handles inbound validation, outbound signing, and secure secret storage and rotation.

Webhook signature verification requires the raw request body because cryptographic signatures must be computed over the exact bytes received. Any parsing or modification of the payload before signature computation invalidates the HMAC verification.