how-to configure public private key authentication between ssh client and ssh server with open ssh

# START ====== configure root auth from client till server

# start from the client $ssh_user@$ssh_client [~] $ 

export ssh_user="the_user"

export ssh_server="the_ssh_server"

# START === how-to implement public private key ( pkk ) authentication 

# create pub priv keys on server

# START copy on the client

test -f ~/.ssh/authorized_keys || ssh-keygen -t rsa 

# copy the rsa pub key to the ssh server

scp ~/.ssh/id_rsa.pub $ssh_user@$ssh_server:/home/$ssh_user/

# to to the server

ssh $ssh_user@$ssh_server

# STOP copy  on the client

# START copy on the server

test -f ~/.ssh/authorized_keys || ssh-keygen -t rsa 

#Hist enter twice if prompted to

cat id_rsa.pub >> ~/.ssh/authorized_keys

cat ~/.ssh/authorized_keys

chmod -v 0700 ~/.ssh

chmod -v 0600 ~/.ssh/authorized_keys

chmod -v 0600 ~/.ssh/id_rsa

chmod -v 0644 ~/.ssh/id_rsa.pub

find ~/.ssh -exec stat -c "%U:%G %a %n" {} \;

rm -fv ~/id_rsa.pub

exit 

# and verify

ssh $ssh_user@$ssh_server

exit

# STOP COPY

# START copy 

# on the client

test -f ~/.ssh/authorized_keys2 || echo ssh-keygen -t dsa

# Hit enter twice if prompted to ...

scp ~/.ssh/id_dsa.pub $ssh_user@$ssh_server:/home/$ssh_user/

ssh $ssh_user@$ssh_server

# START copy on the server

test -f ~/.ssh/authorized_keys2 || ssh-keygen -t dsa

# hit enter twice if prompted to 

scp ~/.ssh/id_dsa.pub $ssh_user@$ssh_server:/home/$ssh_user/

cat id_dsa.pub >> ~/.ssh/authorized_keys2

cat ~/.ssh/authorized_keys2

chmod -v 0700 ~/.ssh

chmod -v 0600 ~/.ssh/authorized_keys2

chmod -v 0600 ~/.ssh/id_dsa

chmod -v 0644 ~/.ssh/id_dsa.pub

find ~/.ssh -exec stat -c "%U:%G %a %n" {} \;

rm -fv ~/id_dsa.pub

exit

# and verify

ssh $ssh_user@$ssh_server

exit

# STOP COPY

# STOP === how-to implement public private key authentication

# STOP ====== configure root auth from ssh_client till ssh_server