It seems to me that the SFTP support in SSHD becomes quite big. With the work envisioned to make it asynchronous, I think it should be in its own maven module, outside sshd-core.
While the SFTP specific API and implementation is quite easy to externalize, there is a touch point though because the SSHD client API does provide access to the SFTP client API. This would have to be broken somehow, but I plan to investigate and propose a PR to discuss soon... Guillaume
