FreeBSD: SSH public/private key (puTTY)

Install puTTY and run puttygen.exe (preferably run as Administrator)

Generate a key pair. Save private key. You do NOT need to save the public key.
Login into the server and go to the home folder of the user.
(either /root or /home/USERNAME)
Here is a download/fetch SH script to do tasks: sshkey.sh

#!/bin/sh
# fetch http://wp.t66.asia/sshkey.sh

echo "run puttygen.exe and generate public/private key"
echo "COPY the public key into clipboard (the pubkey starts with 'ssh-rsa AAA...'"
read -p "for username? " user
if [ -z "$user"  ]; then
   return 0;
fi
if [ "$user" != "root"  ] && [ -e /home/$user ]; then
   echo "unknown user $user"
   return 0;
fi
read -p "PASTE the public key here: " pubkey
pub=$(expr "$pubkey" : '\(.......\)')
if [ "$pub" == "ssh-rsa" ]; then 
  if [ "$user" == "root" ]; then
   mkdir /root/.ssh
   chown root:wheel /root/.ssh
   chmod 700 /root/.ssh
   echo $pubkey > /root/.ssh/authorized_keys
   chown root:wheel /root/.ssh/authorized_keys
   chmod 600 /root/.ssh/authorized_keys
  else
   mkdir /home/$user/.ssh
   chown $user:$user /home/$user/.ssh
   chmod 700 /home/$user/.ssh
   echo $pubkey > /home/$user/.ssh/authorized_keys
   chown $user:$user /home/$user/.ssh/authorized_keys
   chmod 600 /home/$user/.ssh/authorized_keys
   ls -la /home/$user/.ssh/
  fi
   sed -i "" 's|#PubkeyAuthentication yes|PubkeyAuthentication yes|g' /etc/ssh/sshd_config
   service sshd restart
fi

Assuming, we want to add the key pair to user ‘admin‘:
mkdir /home/admin/.ssh # create .ssh folder
chown admin:admin /home/admin/.ssh # set group policy
chmod 700 /home/admin/.ssh # set permissions drwx——
copy the public key from puttygen (the blue highlighted incl. the ssh-rca at the beginning !) and save it in the file /home/admin/.ssh/authorized_keys
chown admin:admin /home/admin/.ssh/authorized_keys # set group policy
chmod 600 /home/$user/.ssh/authorized_keys # set permissions -rw——-
ls -la /home/admin/.ssh/ # verify
EDIT file /etc/ssh/sshd_config and uncomment line PubkeyAuthentication yes
service sshd restart # restart SSH:

Now in puTTY, you can add the private key under connection-SSH-Auth-Credentials.
And that’s it.

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