My host offers SFTP only, not SSH. Can I still use private key authentication? i.e., does SFTP use SSH implicitly?

Question

I'm using WP Engine as my host. They are a managed host and they never offer shell access. However, they do allow setup of SFTP accounts.

My (limited) understanding is that SFTP still uses an SSH tunnel. In other words, SSH is the transport, and through that the provider may activate SFTP, shell access, both, or neither.

If SFTP runs over SSH, shouldn't they be able to drop a key into my user's .ssh directory so that I could authenticate with a key, without providing me shell access?

I'm trying to ask them if they can do this but I am finding it difficult to portray my point, which is that SFTP operates over SSH. Or maybe I'm 100% wrong!

Thanks!

Answer 1

You are correct. sftp uses ssh. They could add a key for you or they may choose not to but they can if they wanted to.