使用下例中ssky-keygen和ssh-copy-id，僅需通過3個(gè)步驟的簡(jiǎn)單設(shè)置而無需輸入密碼就能登錄遠(yuǎn)程Linux主機(jī)。
ssh-keygen 創(chuàng)建公鑰和密鑰。
ssh-copy-id 把本地主機(jī)的公鑰復(fù)制到遠(yuǎn)程主機(jī)的authorized_keys文件上。
ssh-copy-id 也會(huì)給遠(yuǎn)程主機(jī)的用戶主目錄（home）和~/.ssh, 和~/.ssh/authorized_keys設(shè)置合適的權(quán)限 。

步驟1: 用 ssh-key-gen 在本地主機(jī)上創(chuàng)建公鑰和密鑰
ligh@local-host$ ssh-keygen -t  rsa
Enter file in which to save the key (/home/jsmith/.ssh/id_rsa):[Enter key]
Enter passphrase (empty for no passphrase): [Press enter key]
Enter same passphrase again: [Pess enter key]
Your identification has been saved in /home/jsmith/.ssh/id_rsa.
Your public key has been saved in /home/jsmith/.ssh/id_rsa.pub.
The key fingerprint is: 33:b3:fe:af:95:95:18:11:31:d5:de:96:2f:f2:35:f9
ligh@local-host

步驟2: 用 ssh-copy-id 把公鑰復(fù)制到遠(yuǎn)程主機(jī)上
ligh@local-host$ ssh-copy-id -i ~/.ssh/id_rsa.pub  root@192.168.0.3
ligh@remote-host‘s password:
Now try logging into the machine, with ―ssh ?remote-host‘‖, and check in:
.ssh/authorized_keys to make sure we haven‘t added extra keys that you weren‘t expecting.
[注: ssh-copy-id 把密鑰追加到遠(yuǎn)程主機(jī)的 .ssh/authorized_key 上.]

步驟3: 直接登錄遠(yuǎn)程主機(jī)
ligh@local-host$ ssh remote-host
Last login: Sun Nov 16 17:22:33 2008 from 192.168.1.2
[注: SSH 不會(huì)詢問密碼.]
ligh@remote-host$
[注: 你現(xiàn)在已經(jīng)登錄到了遠(yuǎn)程主機(jī)上]