Mac ssh password-free login to linux server

I recently turned into an apple dog, and the terminal directly uses SSH to log into the server. Password-free login server, in fact, the essence is to generate the public key locally and put it on the server, and then the public key will be verified to complete the login when the ssh password is passed.

The steps are as follows:
1. Generate a key locally

lousama-Mac:~ apple$ ssh-keygen -t rsa

     At this time, enter ls ~/.ssh to view the generated public and private keys

lousama-Mac: ~ apple $ ls ~ / .ssh
	id_rsa //private key
	id_rsa.pub //public key

2. Configure ssh config

lousama-Mac: ~ apple $ vim ~ / .ssh / config
    Host test //host abbreviation, after completion, you can log in directly through ssh+abbreviation
    HostName 192.168.xx.xx //Server address
    Port 22 //Server port
    User root //Login name
    PreferredAuthentications publickey //Authentication method here is public key authentication
    IdentityFile ~/.ssh/id_rsa //Private key file

3. The public key is placed on the server
    . Next, the public key is placed on the server.

scp ~/.ssh/id_rsa.pub root@HostName:~/.ssh

Then root login to the remote server

ls ~/.ssh
  id_rsa.pub  authorized_keys

Next, write the public key into authorized_keys, if there is no one under ~/.ssh, create a new one

touch ~/.ssh/authorized_keys   //新建authorized_keys
cat id_rsa.pub >> authorized_keys //write public key

Tips: If the login user is not the root user, then you need to put the public key under /home/user/.ssh, the user corresponds to the login user name

and you're done!
ssh test directly on the local terminal, try to connect?