+ /**
+ * Create a new elliptic curve key pair
+ *
+ * @return array with the elements "prvkey", "pubkey", "vapid-public" and "vapid-private"
+ */
+ public static function newECKeypair()
+ {
+ $openssl_options = [
+ 'curve_name' => 'prime256v1',
+ 'private_key_type' => OPENSSL_KEYTYPE_EC
+ ];
+
+ $conf = DI::config()->get('system', 'openssl_conf_file');
+ if ($conf) {
+ $openssl_options['config'] = $conf;
+ }
+ $result = openssl_pkey_new($openssl_options);
+
+ if (empty($result)) {
+ throw new Exception('Key creation failed');
+ }
+
+ $response = ['prvkey' => '', 'pubkey' => ''];
+
+ // Get private key
+ openssl_pkey_export($result, $response['prvkey']);
+
+ // Get public key
+ $pkey = openssl_pkey_get_details($result);
+ $response['pubkey'] = $pkey['key'];
+
+ // Create VAPID keys
+ // @see https://github.com/web-push-libs/web-push-php/blob/256a18b2a2411469c94943725fb6eccb9681bd75/src/Utils.php#L60-L62
+ $hexString = '04';
+ $hexString .= str_pad(bin2hex($pkey['ec']['x']), 64, '0', STR_PAD_LEFT);
+ $hexString .= str_pad(bin2hex($pkey['ec']['y']), 64, '0', STR_PAD_LEFT);
+ $response['vapid-public'] = Base64UrlSafe::encode(hex2bin($hexString));
+
+ // @see https://github.com/web-push-libs/web-push-php/blob/256a18b2a2411469c94943725fb6eccb9681bd75/src/VAPID.php
+ $response['vapid-private'] = Base64UrlSafe::encode(hex2bin(str_pad(bin2hex($pkey['ec']['d']), 64, '0', STR_PAD_LEFT)));
+
+ return $response;
+ }
+