Securing Webhooks with HTTP Signatures in Elixir

The article emphasizes the need for securing webhooks against potential man-in-the-middle attacks, despite the prevalence of TLS/SSL. Philip Sampaio introduces a method of adding HTTP signatures to webhook requests to enhance their security, following Stripe's specifications. The process involves signing the request body with a secret shared between the server and the client, using the HMAC SHA256 algorithm. The guide further explains how to implement this in Elixir, covering creating and verifying signatures, integrating with Plug and Phoenix, and avoiding timing attacks during signature verification. The article is thorough and contains examples of code implementation, making it practical for developers.