ssh public key to connect to linux server

1. Generate SSH keys

ssh-keygen -t rsa -C "[email protected]"

 rsa and rsa.pub will be generated and saved in the ~/.ssh/ directory by default. rsa is the private key and rsa.pub is the public key.

 

2. Server side settings

Edit etc/ssh/sshd_config 

Uncomment the following lines to enable public key authentication login.

RSAAuthentication yes
PubkeyAuthentication yes
AuthorizedKeysFile      .ssh/authorized_keys
AuthorizedKeysCommand none
AuthorizedKeysCommandRunAs nobody

If you need to prohibit the use of password login, you can set

PasswordAuthentication no

 

restart ssh

service sshd restart

 

3. Create a config file in the .ssh directory (set the server port, when connecting to the git server)

host 192.168.1.101
user git

PreferredAuthentications publickey
identityfile  C:/Users/Administrator/.ssh/admin

hostname 192.168.1.101
port 22

Specifies to use the admin private key for authentication when connecting to the server at 192.168.1.101.

 

4. Upload the public key to the server

Execute the following commands in git bash:

scp ~/.ssh/admin.pub [email protected]: ~/

 

5. Write the public key to the server verification file

Log in to the server as root and switch to the git user.

Create a .ssh/authorized_keys file in the git user directory. Both directories and files must be created.

Then execute the add public key command

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

 

6.   Set file and directory permissions

SSH has very strict requirements on the permissions and ownership of public keys and private keys, which are summarized as follows:

1. Set the permissions of the .ssh directory

 

$ chmod 700 -R .ssh

 

2. Set authorized_keys permissions

 

$ chmod 600 authorized_keys

 

To ensure that both .ssh and authorized_keys have write permissions only for the user. Otherwise validation is invalid.

 

7. ssh public key authentication login

Enter the ssh connection server command

ssh [email protected]

 

If the following information is displayed, the key login is successful.

$ ssh  [email protected]

Last login: Sun Jul  6 22:04:32 2014 from 192.168.1.100

[git@localhost ~]$