Linux下实现免密码登录(超详细)
1.linux下生成密钥
ssh-keygen的命令手册,通过”man ssh-keygen“命令:
通过命令”ssh-keygen -t rsa“
生成之后会在用户的根目录生成一个 “.ssh”的文件夹
进入“.ssh”会生成以下几个文件
authorized_keys:存放远程免密登录的公钥,主要通过这个文件记录多台机器的公钥
id_rsa : 生成的私钥文件
id_rsa.pub : 生成的公钥文件
know_hosts : 已知的主机公钥清单
如果希望ssh公钥生效需满足至少下面两个条件:
1) .ssh目录的权限必须是700
2) .ssh/authorized_keys文件权限必须是600
2.远程免密登录
原理图:
常用以下几种方法:
2.1 通过ssh-copy-id的方式
命令: ssh-copy-id -i ~/.ssh/id_rsa.put <romte_ip>
举例:
[root@test .ssh]# ssh-copy-id -i ~/.ssh/id_rsa.pub 192.168.91.135 root@192.168.91.135's password: now try logging into the machine, with "ssh '192.168.91.135'", and check in: .ssh/authorized_keys to make sure we haven't added extra keys that you weren't expecting. [root@test .ssh]# ssh root@192.168.91.135 last login: mon oct 10 01:25:49 2016 from 192.168.91.133 [root@localhost ~]#
常见错误:
[root@test ~]# ssh-copy-id -i ~/.ssh/id_rsa.pub 192.168.91.135
-bash: ssh-copy-id: command not found //提示命令不存在
解决办法:yum -y install openssh-clients
2.2 通过scp将内容写到对方的文件中
命令:scp -p ~/.ssh/id_rsa.pub root@<remote_ip>:/root/.ssh/authorized_keys
举例:
[root@test .ssh]# scp -p ~/.ssh/id_rsa.pub root@192.168.91.135:/root/.ssh/authorized_keys root@192.168.91.135's password: id_rsa.pub 100% 408 0.4kb/s 00:00 [root@test .ssh]# [root@test .ssh]# [root@test .ssh]# [root@test .ssh]# ssh root@192.168.91.135 last login: mon oct 10 01:27:02 2016 from 192.168.91.133 [root@localhost ~]#
也可以分为两步操作:
$ scp ~/.ssh/id_rsa.pub root@<remote_ip>:pub_key //将文件拷贝至远程服务器
$ cat ~/pub_key >>~/.ssh/authorized_keys //将内容追加到authorized_keys文件中, 不过要登录远程服务器来执行这条命令
2.3 通过ansible实现批量免密
2.3.1 将需要做免密操作的机器hosts添加到/etc/ansible/hosts下:
[avoid close]
192.168.91.132
192.168.91.133
192.168.91.134
2.3.2 执行命令进行免密操作
ansible <groupname> -m authorized_key -a "user=root key='{{ lookup('file','/root/.ssh/id_rsa.pub') }}'" -k
示例:
[root@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== root@localhost.localdomain", "key_options": null, "keyfile": "/root/.ssh/authorized_keys", "manage_dir": true, "path": null, "state": "present", "unique": false, "user": "root" } [root@test sshpass-1.05]#
2.4 手工复制粘贴的方式
将本地id_rsa.pub文件的内容拷贝至远程服务器的~/.ssh/authorized_keys文件中
以上所述是小编给大家介绍的linux下实现免密码登录,希望对大家有所帮助