Validando um Postback

EXPECTED_SIGNATURE=`cat postback_body | openssl dgst -sha1 -hmac "ak_test_grXijQ4GicOa2BLGZrDRTR5qNQxJW0"`
SIGNATURE=1213e67a3b34c2848f8317d29bcb8cbc9e0979b8
if [ "$SIGNATURE" = "$EXPECTED_SIGNATURE" ]; then
    echo "Valid Signature"
fi

require 'pagarme'

PagarMe.api_key = 'ak_test_grXijQ4GicOa2BLGZrDRTR5qNQxJW0';

if PagarMe::PostBack.valid_request_signature?(postback_body, '1213e67a3b34c2848f8317d29bcb8cbc9e0979b8')
    puts "Valid Signature"
end

<?php
require("vendor/autoload.php");
$pagarme = new PagarMe\Client('SUA_CHAVE_DE_API');

$postbackPayload = file_get_contents('php://input');
$signature = $_SERVER['HTTP_X_HUB_SIGNATURE'];
$postbackIsValid = $pagarme->postbacks()->validate($postbackPayload, $signature);

const pagarme = require('pagarme')

// Calculate signature:
pagarme.postback.calculateSignature('apiKey', 'postbackBody')
// returns a hash

// Verify signature:
pagarme.postback.verifySignature('apiKey', 'postbackBody', 'X-Hub-Signature')
// returns true or false

postbackValidate = pagarme.postback.validate("signature", "payload", "api_key")

print(postbackValidate)