This is a rewrite of Piers Harding's php-sapnwrfc extension for PHP 5 to make it work with PHP 7.
The original code is for the PHP 5 extension is Copyright (c) 2010 Piers Harding
This rewrite - though completely rewritten for PHP 7 - would not be possible without his work on the original extension.
Another great source of help was node-rfc - escpecially when it came to handling the UTF-8 <-> UTF-16 conversion.