Password-free login under Linux (Super verbose)

Generate key under 1.Linux

Ssh-keygen's command manual, through the "Man Ssh-keygen" command:

by command "ssh-keygen-t RSA"

A ". SSH" folder will be generated at the user's root directory after the build

Entering ". SSH" will generate the following files

Authorized_keys: The public key that stores the remote password-free login, which records the public key of multiple machines mainly through this file.

ID_RSA: Generated private key file

Id_rsa.pub: Generated Public key file

Know_hosts: List of known host public keys

If you want the SSH public key to take effect, at least two of the following conditions will be met:

1). The SSH directory must have permissions of 700

2). The. ssh/authorized_keys file permission must be 600

2. Remote password-free login

Schematic diagram:

The following methods are commonly used:

　　　2.1 By way of Ssh-copy-id

Command: Ssh-copy-id-i ~/.ssh/id_rsa.put <romte_ip>

Example:

?

1234567891011

[[email protected]test .ssh]# ssh-copy-id -i ~/.ssh/id_rsa.pub 192.168.91.135 [email protected]‘s password: Now try logging into the machine, with "ssh ‘192.168.91.135‘", and check in:.ssh/authorized_keysto make sure we haven‘t added extra keys that you weren‘t expecting.[[email protected]test .ssh]# ssh [email protected]Last login: Mon Oct 10 01:25:49 2016 from 192.168.91.133[[email protected] ~]#

Common errors:

[Email protected] ~]# ssh-copy-id-i ~/.ssh/id_rsa.pub 192.168.91.135

-bash:ssh-copy-id:command not found//prompt command does not exist

Workaround: Yum-y Install openssh-clients

2.2 Writing content to each other's files via SCP

Command: scp-p ~/.ssh/id_rsa.pub [Email Protected]<remote_ip>:/root/.ssh/authorized_keys

Example:

?

123456789

[[email protected]test .ssh]# scp -p ~/.ssh/id_rsa.pub [email protected]:/root/.ssh/authorized_keys[email protected]‘s password: id_rsa.pub 100% 408 0.4KB/s 00:00 [[email protected]test .ssh]# [[email protected]test .ssh]# [[email protected]test .ssh]# [[email protected]test .ssh]# ssh [email protected]Last login: Mon Oct 10 01:27:02 2016 from 192.168.91.133[[email protected] ~]#

　　　　　　It can also be divided into two steps:

$ SCP ~/.ssh/id_rsa.pub [email protected]<remote_ip>:p ub_key//Copy files to a remote server
$ cat ~/pub_key >>~/.ssh/authorized_keys//Append the content to the Authorized_keys file, but log on to the remote server to execute the command

　　　　2.3 Bulk-free through ansible

2.3.1 will need to do a secret-free operation of the machine hosts to add to the/etc/ansible/hosts:

[Avoid Close]
192.168.91.132
192.168.91.133
192.168.91.134

2.3.2 Execution of commands for free-secret operation

Ansible <groupname>-M authorized_key-a "User=root key= ' {{lookup (' file ', '/root/.ssh/id_rsa.pub ')}} '"-K

Example:

?

1234567891011121314

[[email protected]test sshpass-1.05]# ansible test -m authorized_key -a "user=root key=‘{{ lookup(‘file‘,‘/root/.ssh/id_rsa.pub‘) }}‘" -k　　SSH password: ----->输入密码　　192.168.91.135 | success >> {　　"changed": true, 　　"key": "ssh-rsa 　　 AAAAB3NzaC1yc2EAAAABIwAAAQEArZI4kxlYuw7j1nt5ueIpTPWfGBJoZ8Mb02OJHR8yGW7A3izwT3/uhkK7RkaGavBbAlprp5bxp3i0TyNxa/apBQG5NiqhYO8YCuiGYGsQAGwZCBlNLF3gq1/18B6FV5moE/8yTbFA4dBQahdtVP PejLlSAbb5ZoGK8AtLlcRq49IENoXB99tnFVn3gMM0aX24ido1ZF9RfRWzfYF7bVsLsrIiMPmVNe5KaGL9kZ0svzoZ708yjWQQCEYWp0m+sODbtGPC34HMGAHjFlsC/SJffLuT/ug/hhCJUYeExHIkJF8OyvfC6DeF7ArI6zdKER7D8M0SM　　WQmpKUltj2nltuv3w== [email protected]", 　　"key_options": null, 　　"keyfile": "/root/.ssh/authorized_keys", 　　"manage_dir": true, 　　"path": null, 　　"state": "present", 　　"unique": false, 　　"user": "root"　　}　　[[email protected]test sshpass-1.05]#

2.4 How to manually copy and paste

Copy the contents of the local id_rsa.pub file to the remote server's ~/.ssh/authorized_keys file

The above is a small part of the introduction of the Linux implementation of password-free login, I hope that we have some help, if you have any questions please give me a message, small series will promptly reply to you. Thank you very much for the support of the Scripting House website!

Original link: http://www.cnblogs.com/LuisYang/archive/2016/10/12/5952871.html

Password-free login under Linux (Super verbose)