I’ve been trying to set up an SFTP user on our server but authentication always fails.

/etc/passwd shows user sunrisetest and we’re typing the password in correctly but we’re getting a authentication response in filezilla when trying to connect;

Error: Authentication failed.
Error: Critical error
Error: Could not connect to server

When running tail -20 /var/log/auth.log we get the following result;

pam_unix(sshd:auth): authentication failure; logname= uid=0 euid=0 tty=ssh ruser= rhost=***.***.***.***.static.swisp.co.uk user=sunrisetest
Failed password for sunrisetest from ***.***.***.*** port 65042 ssh2

I’m able to su as sunrisetest when logged in as root but not login directly as sunrisetest. Would anyone be able to shed some light on what I’m doing wrong here?

Honestly, it really does look like you're using the wrong password for the user. Reset the password and try again.

Another thing to look at is: SFTP tunnels FTP over SSH so ensure that your user also has permissions to log in to SSH.

I’ve reset the password numerous times thinking that might be the problem but the error message doesn’t change. How do I ensure my user has permission to log in to SSH?

You could just try logging in via ssh to see if you can do it. If you are on a legacy system then you can download PuTTY and try that though it will not have as much diagnostic capability. There is also a 'portable' version if that is needed.

On the server you can also check what kind of configuration the user sunrisetest has to deal with:

I’ve done everything you’ve suggested with no luck. When logging in to SSH, the terminal just closes itself.

Once su as sunriseteset I did sftp -P 3377 -v sunrisetest@***.***.***.***

And got the following response:
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: Applying options for *
debug1: Connecting to ***.***.***.*** [***.***.***.***] port 3377.
debug1: connect to address ***.***.***.*** port 3377: Connection refused
ssh: connect to host ***.***.***.*** port 3377: Connection refused
Couldn't read packet: Connection reset by peer

Does this provide a little more info to help with the issue I’m having?

Which port is sshd really listening on? It looks like you are trying to connect to a port on which it is not listening.