SSH/SCP login using public key authentication in Linux

Address: http://hi.baidu.com/edeed/item/13842c2523a2ae0977272c6d

 

For example, if you want to log on to the 192.168.41.76 server as a root user without entering the user password.

 

1) create a public key and a private key on 192.168.41.76

[192.168.41.76] # ssh-keygen-T RSA

Generating public/private RSA key pair.

Enter file in which to save the key (//. Ssh/id_rsa): // Press enter. The default location is. Ssh/id_rsa.

Enter passphrase (empty for no passphrase): // press enter without a password

Enter same passphrase again: // press enter without a password

Your identification has been saved in //. Ssh/id_rsa.

Your public key has been saved in //. Ssh/id_rsa.pub.

The key fingerprint is:

F3: 66: 3D: 23: 9f: Cf: 78: 0b: F8: 58: 8f: 3D: EE: BA: 55: 99 root @ dw_test1

[192.168.41.76] # LL ~ /. SSH

-RW ------- 1 Root 883 Jun 30 14:25 id_rsa

-RW-r -- 1 Root 221 Jun 30 14:25 id_rsa.pub

Note:

-T rsa indicates that SSH generates an RSA key, which is the default behavior. you can also generate a DSA-type key. view. two files are added to the SSH folder. id_rsa is the private key and id_rsa.pub is the public key.

2) check whether there is ~ On 192.168.41.75 ~ /. Ssh directory, create first

[192.168.41.75] # LL ~ /. SSH

[192.168.41.75] # mkdir ~ /. SSH

3) Use SCP on 192.168.41.76 to copy the Public Key id_rsa.pub to 192.168.41.75.

[192.168.41.76] # SCP ~ /. Ssh/id_rsa.pub root@192.168.41.75 :~ /

Root@192.168.41.75's password: // enter the remote server root login password

4) append the id_rsa.pub content to the corresponding user's ~ /. Ssh/authorized_keys file, and delete the id_rsa.pub File

[192.168.41.75] # Cat ~ /Id_rsa.pub> ~ /. Ssh/authorized_keys

[192.168.41.75] # rm-F id_rsa.pub

5) in this way, you can log on to 192.168.41.75 as a root user without entering the password. A known_hosts file is also added.

[192.168.41.76] # SSH 192.168.41.75

[192.168.41.76] # LL ~ /. SSH

-RW-r -- 1 Root 221 14:25:32. 000000000 + 0800 id_rsa.pub

-RW ------- 1 Root 883 14:25:32. 000000000 + 0800 id_rsa

-RW-r -- 1 Root 223 14:30:26. 000000000 + 0800 known_hosts

6) Note

. The SSH directory permission must be 0700 ,. the SSH/authorized_keys File Permission must be 0600; otherwise, public key authentication will not take effect. if you want to directly access other users of 192.168.41.75, You need to append the public key to the authorized_keys file of another user.

-- End --

# Linux