<?php
include 'Crypt/RSA.php';
$rsa = new Crypt_RSA();
$payment = base64_decode($_POST ["payment"]);
$signature = base64_decode($_POST ["signature"]);
$publickey = "-----BEGIN PUBLIC KEY----- SOMEKEYSOMEKEYSOMEKEYSOMEKEYSOMEKEYSOMEKEYSOMEKEY -----END PUBLIC KEY-----";
$rsa->loadKey($publickey);
$signature_status = $rsa->verify($payment, $signature) ? TRUE : FALSE;
echo $signature_status;
?>

const NodeRSA = require('node-rsa');
const decryptionKey = new NodeRSA(PUBLIC_KEY);
decryptionKey.setOptions({signingScheme: 'pss-sha1'});

module.exports.handlePaymentCallback = function (req, res, next) {
    const signature = Buffer.from(req.body.signature, 'base64').toString();
    const payment = Buffer.from(req.body.payment, 'base64').toString();
    let result = decryptionKey.verify(payment, signature);
}

const constants = process.binding('constants').crypto;
const crypt = require('crypto');

module.exports.handlePaymentCallback = function (req, res, next) {
    const signature = Buffer.from(req.body.signature, 'base64').toString();
    const payment = Buffer.from(req.body.payment, 'base64').toString();
    const verifier = crypt.createVerify('RSA-SHA1');
    verifier.update(new Buffer('' + payment, 'utf8'));
    const options = {key: PUBLIC_KEY};
    let result = verifier.verify(options, signature);
}