PHP Diffie Hellman Implementation

ECCTest.php

<?php

namespace Tests\ArikCrypto;

use BitcoinPHP\BitcoinECDSA\BitcoinECDSA;

class ECCTest extends \PHPUnit_Framework_TestCase {

	public function testDiffieHellman() {

		$ecdsa1 = new BitcoinECDSA();
		$ecdsa1->generateRandomPrivateKey(mcrypt_create_iv(32));

		$ecdsa2 = new BitcoinECDSA();
		$ecdsa2->generateRandomPrivateKey(mcrypt_create_iv(32));

		$pub1 = $ecdsa1->getPubKeyPoints();
		$priv1 = $ecdsa1->getPrivateKey();

		$pub2 = $ecdsa2->getPubKeyPoints();
		$priv2 = $ecdsa2->getPrivateKey();

		$productA = $this->diffieHellman($pub1, $priv2);
		$productB = $this->diffieHellman($pub2, $priv1);

		var_dump($productA);
		var_dump($productB);

		$this->assertEquals($productA, $productB);

	}

	private function diffieHellman($publicKeyPoints, $privateKey){
		$ecdsa = new BitcoinECDSA();
		$normalizedPublicKey = [
			'x' => '0x'.$publicKeyPoints['x'],
			'y' => '0x'.$publicKeyPoints['y']
		];
		$product = $ecdsa->mulPoint($privateKey, $normalizedPublicKey);
		$secretPoints = [
			'x' => gmp_strval($product['x'], 16),
			'y' => gmp_strval($product['y'], 16)
		];
		return $secretPoints;
	}

}