Securing Online Checkout Pipelines

Payment integrations demand strict signature checks and idempotent state transitions.

Webhook hardening checklist

• Validate signature headers
• Reject stale timestamps
• Enforce idempotency keys
• Log each transition with actor + payload hash

Example hash verification

$expected = hash_hmac('sha256', $payload, $secret);
if (! hash_equals($expected, $signature)) {
    abort(401, 'Invalid signature');
}