LinkStation Pro Duo, enabling SSH

What I did to enable SSH on my LinkStation Pro Duo:

IMPORTANT NOTE: I made a few corrections to the below by adding item 3.6, and updating items 4.4, 5.11, and 5.12. Please read those items over again. If you needed to perform items 5.11 and 5.12 for two PCs, it is important that you use the updated commands.

  1. Enable Telnet (temporarily)

    1. Download the acp-commander
    2. Run the .jar file by running
      java -jar acp_commander.jar -t <IP ADDRESS> -o
    3. Login to your LinkStation Pro Duo using (username and password are found on the above link)
      telnet <IP ADDRESS>
  2. Enable SSH at Startup

    1. Create an SSH Startup script by typing vi /etc/init.d/sshd.sh
    2. Type ‘i’ to enter Interactive Mode (this enables you to type), then proceed to type the following code:
      #!/bin/sh
      test -f /usr/local/sbin/sshd || exit 0

      ACTIVE_FILE=/var/run/active_sshd

      case "$1" in
      start) echo -n "Start services: sshd"
      /usr/local/sbin/sshd -f /etc/sshd_config 2>/dev/null &
      touch $ACTIVE_FILE
      ;;
      stop) echo -n "Stop services: sshd"
      killall sshd
      rm -f $ACTIVE_FILE
      ;;
      restart) $0 stop
      $0 start
      ;;
      *) echo "Usage: $0 start | stop | restart"
      exit 1
      ;;
      esac
      exit 0

    3. Press the ESC key and type “:wq” to Save and Exit
    4. Make the file executable by running
      chmod +x /etc/init.d/sshd.sh
    5. Backup the original script startup file by running
      cp /etc/init.d/rcS /etc/init.d/rcS.bak
    6. Modify the rcS file to contain the SSH startup script by typing the following:
      vi /etc/init.d/rcS
    7. Press “i” to enter Interactive Mode
    8. Page Down till you see
      echo "** step3 **"
    9. At the end of the next line, add
      sshd.sh
    10. Your change should now look similar to the following:
      for cmd in diskmon.sh drivecheck.sh ftpd.sh atalk.sh httpd.sh smb.sh clientUtil_servd.sh bonjour.sh lsprcvd.sh daemonwatch.sh logrotate_init.sh cron.sh checkconfig.sh ups.sh pwrmgr.sh sshd.sh
    11. Save your changes and exit by pressing the ESC key and typing :wq
    12. Add your SSH script to the Daemon Watch, so if it crashes/closes, it will be started again automatically. Run the following code to edit the list
      vi /etc/daemonwatch.list
    13. Type “i” to enter Interactive Mode
    14. Add the following line to the file
      /var/run/sshd.pid /var/run/active_sshd /etc/init.d/sshd.sh restart
    15. Save your changes and exit bt pressing the ESC key and typing :wq
  3. Configure SSH

    1. Backup your original sshd_config file by typing
      cp /etc/sshd_config /etc/sshd_config.bak
    2. Modify the sshd_config file by typing
      vi /etc/sshd_config
    3. Press “i” to enter Interactive Mode
    4. Remove the # in front of the following lines (you need to use the backspace key to do this; you may also need to change some of the ‘no’ values to ‘yes’)
      Port 22
      Protocol 2,1

      HostKey /etc/ssh_host_key
      HostKey /etc/ssh_host_rsa_key
      HostKey /etc/ssh_host_dsa_key

      PermitRootLogin yes
      StrictModes yes

      RSAAuthentication yes
      PubkeyAuthentication yes

    5. Save the file by pressing the ESC key then typing :wq
    6. Start the SSH Server by running /etc/init.d/sshd.sh start
  4. Create new Home folders for each user
    You will need to do the following for every user you have created!

    1. Create the users via the Web Interface first, once the users are created, start Step 2 for each user
    2. Create a directory for the user by typing (replace <username> with the actual username)
      mkdir /home/<username>
    3. Give the user permission to that folder by typing
      chown <username>.<group> /home/<username>
      Now this is a bit tricky, depending how you setup the groups. You want to give the permission to a valid user and a group the user is part of. For example, if you have a user named “matt” and a group named “contributor”, then your command would be
      chown matt.contributor /home/matt
    4. Finally, make sure the directory has the correct permissions by running the following command
      chmod 0755 /home/<username>
    5. Set the user’s home directory by running
      usermod -d /home/<username> <username>
  5. Create public/private key pairs for each user
    You will need to do the following for every user you have created!
    I am only going to go over the commands you would use in Linux as I haven’t tried this with PuTTY yet. You will need to do these steps as “each user”. In other words, you will have to logout on your PC, login as the next user and repeat the commands (advanced users can use su <username> to login as an additional user without logging out as their own).

    1. Run the following command in Terminal or Konsole on YOUR PC
      ssh-keygen
    2. Leave the file name as “id_rsa”
    3. If you want a passphrase enter it here, otherwise, leave it blank (I left mine blank)
    4. Next run the following command to generate a SSH 2 key
      ssh-keygen -t dsa
    5. Leave the file name as “id_dsa”
    6. If you want a passphrase enter it here, otherwise, leave it blank (I left mine blank)
    7. Next copy the files to your LinkStation by running
      scp .ssh/*.pub <username>@<IP ADDRESS>:/home/<username>
    8. Next login to the LinkStation via SSH using
      ssh <username>@<IP ADDRESS>
    9. Once login run the following command to create your SSH key directory
      mkdir .ssh
    10. Make sure the permissions are set properly by running
      chmod 0700 .ssh
    11. Load the public key for SSH 1 by running
      cat id_rsa.pub >> .ssh/authorized_keys
    12. Load the public key for SSH 2 by running
      cat id_dsa.pub >> .ssh/authorized_keys2
    13. Make sure the public key entries for SSH have the correct permissions by running
      chmod 0600 .ssh/authorized_keys*
    14. Exit out of the LinkStation by typing “exit”
    15. Try step 8 again and make sure it did not ask for your password this time (if you entered a passphrase, you will be prompted for your passphrase)

Download the sshd_config.zip

6 comments ↓

#1 Using rdiff-backup with your LinkStation Pro Duo — cpradio’s tidbits of information on 12.04.08 at 10:38 pm

[...] ← LinkStation Pro Duo, enabling SSH [...]

#2 Volker Edelmann on 01.20.09 at 3:30 am

Hi,
thanks for your very helpful instructions.
I would like to add a hint as for my linkstation

ssh user@localhost

did not work. It resulted in an error related to the machines host key.
I had to remove the files “/etc/ssh_host_*key*” and regenerate new keys using “ssh-keygen”:

ssh-keygen -t dsa -f /etc/ssh_host_dsa_key
ssh-keygen -t rsa -f /etc/ssh_host_rsa_key

Cheers

Volker

#3 cpradio on 01.20.09 at 4:44 am

@Volker,

Thanks for the information. That step doesn’t seem familiar to me by any means, nor a friend of mine so maybe they changed something with the LinkStations again. I know my initial steps were definitely different than those by another person too (to be fair, mine were entirely different as he hosted root over ssh).

Thanks for the updated and how you fixed it. That may help a lot of individuals out.

#4 Equinoxefr on 01.21.09 at 12:51 pm

Hello,

Thank’s for your tutorial. For steps 7 to 15, if you want, you can do this:

ssh-keygen -t dsa

ssh-copy-id -i /home/XXXX/.ssh/id_dsa YYYY@your_nas

Where XXXX is your local user and YYYY user on your nas. It’s a bit fastest than manual copy.

Pierre

#5 Kamal Abou Mikhael on 02.28.09 at 6:28 am

Can someone make the original LinkStation Duo Pro sshd_config file available on the net?

I had ssh running on my Duo Pro, but one day I was not

I re-ran acp_commander and found all my data missing and even this key file.

#6 cpradio on 03.03.09 at 4:10 pm

Hi Kamal, I have added the sshd_config file from my LinkStation to this post.

Feel free to download it.

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