SSH Password-free login

SSH does not have password logon to use the public key and private key. Linux can be used to generate a ssh-keygen public/private key pair, below I take centos for example.

There is machine A (192.168.1.155), B (192.168.1.181). Now want a password to login to B via SSH.

1. Generate a public/private key pair under a machine. [Chenlb@a ~]$ ssh-keygen-t rsa-p '

-p means the password,-p ' means null password, also can not use the-p parameter, this will be three car return, with-P on a return.
It generates an. SSH directory under/HOME/CHENLB,. SSH has Id_rsa and id_rsa.pub.

2. Copy the id_rsa.pub under a machine to B machine, in the B-machine. ssh/authorized_keys file, I use SCP to copy. [Chenlb@a ~]$ SCP. Ssh/id_rsa.pub chenlb@192.168.1.181:/home/chenlb/id_rsa.pub
chenlb@192.168.1.181 ' s Password:
Id_rsa.pub 100% 223 0.2kb/s 00:00

Because there is no password-free login, you need to enter a password.

The 3.B machine adds the id_rsa.pub copied from the a machine to the. ssh/authorzied_keys file. [Chenlb@b ~]$ cat id_rsa.pub >> Ssh/authorized_keys
[Chenlb@b ~]$ chmod Ssh/authorized_keys

Authorized_keys's permission is 600.

4.A Machine login B machine. [Chenlb@a ~]$ ssh 192.168.1.181
The authenticity of host ' 192.168.1.181 (192.168.1.181) ' can ' t be established.
RSA key fingerprint is 00:a6:a8:87:eb:c7:40:10:39:cc:a0:eb:50:d9:6a:5b.
Are you sure your want to continue connecting (yes/no)? Yes
warning:permanently added ' 192.168.1.181 ' (RSA) to the list of known hosts.
Last Login:thu June 3 09:53:18 2008 from CHENLB
[Chenlb@b ~]$

The first time you log in is when you enter Yes.

Now a machine can log on to the B machine without a password.

Summary: The login can have a private key, the machine is logged in to have the public key of the machine. This public/private key pair is typically generated in the private key host host. The above is the RSA algorithm with the public/private key pair, of course, can also use DSA (corresponding file is id_dsa,id_dsa.pub)

want to let a,b machine without password to log on, that B machine in the same way as the above configuration can be.

Reference: Ssh-keygen usage  http://blog.163.com/chen98_2006@126/blog/static/158584272007101862513886/