Webhook Security

OAuth2, JWTs, and JWKs

  • Very High
ProsEnables additional security features such as:
  • Message payload formatting with JSON Web Tokens (JWTs)
  • APIs for public key release and rotation with JSON Web Keys (JWKs)
  • Ability to use third-party OAuth Authorization servers for webhook authentication
  • High complexity
  • As of today, we couldn't find a standard approach for using JWTs, JWKs, and OAuth in webhooks

Webhook providers such as SendGrid, Wix, and Brex use security methods and protocols typically found in REST APIs — such as OAuth, JSON Web Tokens (JWTs), and JSON Web Keys (JWKs) — in creative ways to protect their webhooks:

  • SendGrid uses OAuth as a client. Before sending a webhook message, SendGrid authorizes itself against third-party OAuth Authorization Servers to issue access tokens. Webhook listeners must validate the OAuth token to ensure the request is trusted and authorized using the validation method defined by the OAuth Authorization Server.
  • Brex uses OAuth to release webhook keys. Brex uses HMAC with symmetric SHA256 keys for webhook validation. However, webhook listeners must request a REST API (GET /v1/webhooks/secrets) protected with OAuth to obtain the shared key. The call should happen regularly to prevent downtime after a key rotation.
  • Wix uses JWT in the webhook payload. Wix implements JWT in the webhook payload. Webhook listeners validate the webhook signature following the JWT standard, using a public certificate provided by Wix in the webhook registration.
  • Janrain (an Akamai product) uses JWKs and JWTs in webhook notifications. Janrain takes a similar approach to Wix and sends a JWT in the webhook payload for validation. However, instead of shipping public certificates in the webhook registration, they implement the JSON Web Key (JWK) standard and endpoint to obtain the public keys for webhook validation.
  • Plaid uses JWTs and JWKs in webhook notifications, but not on the message. Plaid uses JWTs and JWKs like Janrain but stores the JWT in the plaid-verification header and uses the webhook payload to send information.
Asymmetric Keys