I was searching for a basic bridge for being able to view/browser/manipulate files on an SFTP server via a web browser and could not come up with any good solutions, so I wrote a very, very basic implementation of one in PHP.
This extends the sabre/dav API and uses the PHP SSH2 library to do the translations between WebDAV and SFTP. Feel free to contribute and submit Pull Requests for it, if you like, or take it and use it.
This is licensed under the Apache 2.0 license.
The example.php file provides an example of how to use the library along with sabre/dav. You'll need composer installed in order to download the sabre/dav packages - a composer.json file is also provided, here, to pull in those depenencies, which can be used with either a local or system install of composer. For installation instructions for composer, see: