Choose the signature algorithm for webhook validation:

• SHA-256 (Recommended): Modern, secure HMAC signature validation using the X-Hub-Signature-256 header. This is GitHub's recommended approach for enhanced security.
• SHA-1 (Legacy): Legacy HMAC signature validation using the X-Hub-Signature header. Only use this for existing webhooks during migration period.

Note: When changing algorithms, ensure your GitHub webhook configuration uses the corresponding signature header (X-Hub-Signature-256 for SHA-256 or X-Hub-Signature for SHA-1).

System Property Override: The default algorithm can be overridden using the system property -Djenkins.github.webhook.signature.default=SHA1 for backwards compatibility with legacy CI environments.