SSH password free login

linux To configure ssh Password free login ：

explain ：ssh The security shell for remote login has identity authentication mechanism ：

       —— user name + password

       —— Key login

   Introduction to the environment ：

            host1:156.3.203.128

            host2:156.3.203.251

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1. stay host1 Generate public key under host / Private key pair

Execute the following command , Keep going back

[[email protected] ~]# ssh -keygen -t rsa

After command execution , stay /home/user Lower generation .ssh Catalog ,.ssh Directory is id_rsa and id_rsa.pub Two documents .

2、 take host1 Under the main engine id_rsa.pub Copied to the host2 Under the main engine

There is no password free login at this time , So enter host2 Password

3、host2 The host must copy the id_rsa.pub The contents of the file are added to /home/user/.ssh/authorzied_keys In file

     Need modification authorized_keys The permission of the file is 600

testing ：

Now? host1 The host can log in without password host2 The main engine

explain ： The first 2、3 Step can be done with one command ：ssh-copy-id 192.168.0.11

summary ： The logged in machine can have a private key , The logged in machine must have the public key of the logged in machine . This public key / The private key pair is usually generated on the private key host .
It's for rsa The public key of the algorithm / Private key pair , You can also use it dsa( The corresponding file is id_dsa,id_dsa.pub)
Want to make host1,host2 Mutual login without password , that host2 The host can be configured in the same way as above