How to enable jailed shell access with authenticated keys authentication instead (or in addition) to password authentication.
- This article requires you to have access to another server with full SSH access (not jailed) and access to the command line program “ssh-keygen”. If you don’t have access to another server with this program, you will not be able to proceed.
- This article requires you to have jailed shell access enabled in your hosting account. Please see: how-do-i-access-my-zenutech-account-by-ssh
On the second server which has access to “ssh-keygen”, we create a passphraseless key
#create the key, leaving the passphrase blank when requested (your choice if you want to use a passphrase in your key).
#The path to ssh-keygen will be different depending on your second server.
/usr/local/bin/ssh-keygen -t rsa -b 4096 -f ~/zenutech-jailed.sshkey
# The above step will have created TWO files: zenutech-jailed.sshkey AND zenutech-jailed.sshkey.pub
# Copy the new zenutech-jailed.sshkey.pub file to the jailed shell at Zenutech either by FTP or by scp, and place it in the home folder (~).
# If your home folder is /home/user123 , then place the file at /home/user123/zenutech-jailed.sshkey.pub
# NOTE, COPY ONLY THE .PUB FILE TO THE ZENUTECH SERVER
# You can add additional security by limiting access to your jailed shell with this special key, to a particular IP or IP range.
# For example, you could allow 123.123.123.* to connect, or an individual IP such as 188.8.131.52
# In this example, we will allow 123.123.123.* to connect
#While logged into your jailed shell at Zenutech
chmod 700 ~/.ssh;
chmod 600 ~/.ssh/authorized_keys;
echo “from=123.123.123.* ” >> ~/.ssh/authorized_keys
cat ~/zenutech-jailed.sshkey.pub >> ~/.ssh/authorized_keys;
# That’s it, you are done. Test! You should now be able to connect without a password from server #2 to your jailed shell account at Zenutech.
# For example: ssh useratzenutech@yourdomainname -p 3345 -i zenutech-jailed.sshkey
# this should log you in without asking for a password
# you can also remove the file zenutech-jailed.sshkey.pub from the jailed shell as it is no longer needed, although it shouldn’t do much harm if you leave it there. (rm /home/user123/zenutech-jailed.sshkey.pub)