如何實現Linux主機遠程登錄ssh免密碼
作者：好大的刀
本文作者公司剛上幾臺Linux，現在要把主機之間實現都能遠程ssh免密碼登陸。方法很簡單，使用ssh-keygen在主機A上生成private和public密鑰，將生成的public密鑰拷貝到遠程機器主機B上后，就可以使用ssh命令無需密碼登錄到另外一臺機器主機B上。
【引自xxxx的博客】一、情景
公司剛上幾臺Linux，現在要把主機之間實現都能遠程ssh免密碼登陸。
二、原理
很簡單，使用ssh-keygen在主機A上生成private和public密鑰，將生成的public密鑰拷貝到遠程機器主機B上后，就可以使用ssh命令無需密碼登錄到另外一臺機器主機B上。
三、步驟
主機A：
1.生成公鑰和私鑰文件id_rsa和id_rsa.pub (敲三下回車即可)。
- [root@bogon ~]# 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):
- 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:
- 67:da:0d:79:e0:d6:2b:cd:7d:22:af:51:7e:9c:75:fe root@bogon
- The key's randomart image is:
- +--[ RSA 2048]----+
- | |
- | |
- | . |
- | . + |
- | S B o . o|
- | * * = o+|
- | . o B +.=|
- | . + +.|
- | ... E|
- +-----------------+
2.ssh-cop-id命令會將指定的公鑰文件復制到遠程計算機。
- [root@bogon ~]# ssh-copy-id -i ~/.ssh/id_rsa.pub root@10.1.250.166
- The authenticity of host '10.1.250.166 (10.1.250.166)' can't be established.
- RSA key fingerprint is c8:9d:6d:92:55:77:3d:3e:af:f5:cb:18:80:5a:47:93.
- Are you sure you want to continue connecting (yes/no)? yes
- Warning: Permanently added '10.1.250.166' (RSA) to the list of known hosts.
- reverse mapping checking getaddrinfo for bogon [10.1.250.166] failed - POSSIBLE BREAK-IN ATTEMPT!
- root@10.1.250.166's password: <主機B的登陸密碼>
- Now try logging into the machine, with "ssh 'root@10.1.250.166'", and check in:
- .ssh/authorized_keys
- to make sure we haven't added extra keys that you weren't expecting.
3.然后ssh登陸主機B驗證是否需要密碼。
- [root@localhost ~]# ssh 10.1.250.166
- reverse mapping checking getaddrinfo for bogon [10.1.250.166] failed - POSSIBLE BREAK-IN ATTEMPT!
- Last login: Wed Oct 21 10:05:39 2015 from 10.1.250.141
- [root@bogon ~]#
4.登陸成功后，我們需要在主機B也做下以上3步，這樣就可以相互免密碼ssh登陸。(如果有多臺主機，每臺主機都做下相同操作，以方便以后管理)。
5.權限問題
建議用其他用戶做ssh登陸的話，調整目錄文件權限。
設置authorized_keys權限
- chmod 644 authorized_keys
設置.ssh目錄權限
- chmod 700 -R .ssh
6.要保證.ssh和authorized_keys都只有用戶自己有寫權限。否則驗證無效。
本文出自 “好大的刀” 博客，請務必保留此出處：http://53cto.blog.51cto.com/9899631/1704792
責任編輯：火鳳凰
來源：
51CTO博客
