SSH Login Without Password

因為文章裡會 reference 比較多次，所以乾脆獨立出來。

當你的機器設備較多時，密碼認證就變成一種相當大的負擔，用 keys 來認證，相對成為認證方式首選！

Step1. 產生 key pair

產生認證所需的 key

[root@nodeB ~] # ssh-keygen -t rsa

Generating public/private rsa key pair.

Enter file in which to save the key (/root/.ssh/id_rsa):

Enter passphrase (empty for no passphrase): # 請注意，這是存取 private key 的密碼，如果你想做 auto login, 請不要輸入任何東西。

Enter same passphrase again:

Your identification has been saved in /root/.ssh/id_rsa.

Your public key has been saved in /root/.ssh/id_rsa.pub.

The key fingerprint is:

2d:52:2c:9f:d9:f8:7a:35:83:d8:12:7e:cc:4d:2a:ff root@nodeB

The key's randomart image is:

+--[ RSA 2048]----+

| |

| . |

| . o |

| +.* . |

| ..S*o= |

| .=oB = |

| =.o o |

| .o E |

| .. |

+-----------------+

Step2. 佈署 public key

若您要從 nodeB, 以 ssh w/o passwd 進入 nodeA

請將 nodeB 的 public key, 放置於 nodeA, /UserAccount/.ssh/authorized_keys

[root@nodeA ~] # cat /root/.ssh/authorized_keys

ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAQEAwLmrP46JukEdUjHhK1tsyhHgTtKd65nlxHjSdVDBtXLvYukYMij3qX1qLOG9x2gQBWt2WBOyacULi5HajexMuU9aQTTTYdHXbA+Vyn/tO26

NkGVXiQm0LFZpRBqQBrhUcvTeOD0yHmMC9iqbEUBpyQXA8XELZNoKrYGOIKiPHpfduaeYfnt7nZ7T7Nou/MoFbpuvXmfpeVg6S01gPMOKXpkgFrigwtcw/W59d7ia5I6rhPEIrkHQjGGN/Q

N6NCifvtkIeWt+UY2lz1f+hhmvtKC6esiY3y7U3U9iLrSHBLHh+Tm5KLcKhJw1qgnDu8vsj7uL5DMg6kk98CZKuKi+== root@nodeB

Step3. 測試連線

[root@nodeB ~] # ssh -2 nodeA

Last login: Thu Apr 22 12:33:07 2010 from nodeB

[root@nodeA ~] #