Since DSM 6.0 the user to login via SSH must be member of the administrator group. Root login is not permitted anymore, but after login you can elevate with

sudo -i

As the homes directory is now controlled by ACL, you need to disable StrictModes, otherwise SSH will not allow to read the authorized_keys file. Copy the public key for the client machine to grant access to the DS to ~/.ssh. Make sure directory .ssh and content have the correct permissions set.

Then modify /etc/ssh/sshd_config as follows and reboot the DS:

LoginGraceTime 15
PermitRootLogin without-password
StrictModes no # set to yes unless the homes directory is controlled by ACL
PasswordAuthentication no
AllowTcpForwarding yes
PermitTunnel yes

Log into the web interface

Control Panel > Users > User Home > Enable user home services

This enables path /var/services/homes and below this, all users which are registered to the system.

Adding a user through the web interface does not set all necessary settings for SSH / shell access:

1. create directory /var/services/homes and /var/services/homes/<username> with proper privileges as root
2. copy .profile from /root to /var/services/homes/<username> and edit it's contents
3. you might wish to change the default prompt to PS1=“\u@\h:\w\$ ” in .profile
4. if you installed sudo, also add SUDO_PS1 with the same prompt to .profile

Do the following as root:

chmod 4755 /bin/busybox
cd /var/services/homes/username
mkdir .ssh
chown username:users .ssh
cp /root/.ssh/authorized_keys .ssh
chown username:users .ssh/authorized_keys
chmod 400 .ssh/authorized_keys
cp /root/.profile /var/services/homes/username
vi .profile
-- change the line that reads “HOME=/root” to “HOME=/var/services/homes/username”
chmod 600 .profile
vi /etc/passwd
-- make sure your home is /var/services/homes/username and change shell from /sbin/nologin to /bin/sh or /bin/ash

If you want to establish tunnels to services on the NAS, you need to enable TCP forwarding:

# vi /etc/ssh/sshd_config
AllowTcpForwarding yes
PermitTunnel yes

Check configuration of sshd_config before reloading or restarting:

# sshd -t
# /etc/init.d/ssh reload

Change the shell prompt for root:

$ vim ~/.profile
SUDO_PS1='\[\033[01;31m\]\u@\h\[\033[00m\]:\[\033[01;34m\]\w\[\033[00m\]\$ '
export SUDO_PS1

This will create root@DiskStation: vs. user@DiskStation:

Set the SSH Port in Control Panel / Terminal.

Make sure the NAS is configured correctly to access the internet, e.g. default gateway and DNS settings must be correct.

Enable telnet in web interface > Control Panel > Terminal

telnet box # as username
ssh -v -v -v box # as root

Pubkey SSH for non-root users

Enabling the Command Line Interface