Simply Log in Remote Servers with Config File

I always have trouble remembering various passwords. Also, it is trouble keying passwords everytime login remote servers. Recently, I find it convenient connecting servers by using SSH config file.

To make things simple and clear, suppose a user with following information”

user: username
server: example.com

With Passwords

Previously, what I do to connect a remote server

ssh username@example.com
password: **************

It is not too bad when only one server is used. Image when you got three or more servers…

Free Login

But now, we can make it simpler and more secure by using public/private key pairs.

Edit config file

Enter path /.ssh from local root path. There is a file named config, if not, create one. Enter the SSH config file, it should look like:

Firstly, enter path ~/.ssh. There should be a file name config where the content is like:

Host 
Hostname 
User

Generate key files

What we need to do next is to generate the public/private key pair.

To generate key pairs, we type command

ssh-keygen

Then it will ask you to enter the file name to save the key and enter the passphrase, you can name the file as an alias name , example in this case, and leave passward as empty. Once the files are generated, there are two new files named example and example.pub.

Configurate sever

Subsequently, copy public key file from local to remote server and copy public key to the file authorized_keys.

scp example.pub username@exampleIP:/home/username/.ssh
cat example.pub >> authorized_keys

Then, execute following commands to get permission

chmod 700 ~/.ssh/
chmod 600 authorized_keys

Note that if the path /.ssh or the file authorized_keys do not exist, then create them. All of above operations should be done in server.

Config local config file

Then we fill our own information like:

Host example 
Hostname example.com
User username
IdentityFile ~/.ssh/example

Test

Now, you are able to connect the remote server without keying passwords.

ssh example

That’s it. In the future, if you have new server, add information about the server in config file and follow above instructions.

This totally makes my day.

References

利用 ssh 的用户配置文件 config 管理 ssh 会话
Mac ssh 远程登录 无需密码验证 设置

赏

谢谢你请我吃糖果