ssh免密码快速登录_ll@ll-virtual-machine:~/.ssh$ ssh-keygen -t rsa ge

首先明确，从userA通过ssh免密码登录到userB

1、在userA终端输入命令：ssh-keygen -t rsa

一路回车后出现下列信息：

wrf@wrf-virtual-machine:~$ ssh-keygen -t rsa
Generating public/private rsa key pair.
Enter file in which to save the key (/home/wrf/.ssh/id_rsa): 
Enter passphrase (empty for no passphrase): 
Enter same passphrase again: 
Your identification has been saved in /home/wrf/.ssh/id_rsa.
Your public key has been saved in /home/wrf/.ssh/id_rsa.pub.
The key fingerprint is:
SHA256:uOWi24pciEx7zFrnQFaiZqcmNZe9dzkVNCJUOa9mplQ wrf@wrf-virtual-machine
The key's randomart image is:
+---[RSA 2048]----+
|       .o.o.o    |
|         .oo .   |
|   . .     o.    |
|  . oo .  E ..   |
| =o+o o S. ..    |
|=oO+   =. =o     |
|o=.*..+.o=+      |
|o.+o+o o.. .     |
| .o ++.          |
+----[SHA256]-----+

 此时进入.ssh目录会看到id_rsa.pub文件，说明密钥对已经生成

wrf@wrf-virtual-machine:~/.ssh$ ll
total 20
drwx------  2 wrf wrf 4096 1月  21 09:58 ./
drwxr-xr-x 30 wrf wrf 4096 1月  19 11:49 ../
-rw-------  1 wrf wrf 1679 1月  21 09:58 id_rsa
-rw-r--r--  1 wrf wrf  405 1月  21 09:58 id_rsa.pub
-rw-r--r--  1 wrf wrf  666 1月  13 13:43 known_hosts

2、在userA终端输入命令：ssh-copy-id userB@192.168.1.112

注意：其中userB为有要登录的远端服务器@后面是远端服务器的ip地址

wrf@wrf-virtual-machine:~$ ssh-copy-id nvidia@192.168.1.112
/usr/bin/ssh-copy-id: INFO: attempting to log in with the new key(s), to filter out any that are already installed
/usr/bin/ssh-copy-id: INFO: 1 key(s) remain to be installed -- if you are prompted now it is to install the new keys
nvidia@192.168.1.112's password: 
Number of key(s) added: 1
Now try logging into the machine, with:   "ssh 'nvidia@192.168.1.112'"
and check to make sure that only the key(s) you wanted were added.

3、使用ssh登录userB，发现已经不用密码登录，进入.ssh文件夹可以看到id_rsa.pub文件已经被copy到userB的.ssh目录下

nvidia@tegra-ubuntu:~$ ls -ll .ssh/
total 16
-rw------- 1 nvidia nvidia 2009 1月  17 12:34 authorized_keys
-rw------- 1 nvidia nvidia 1679 1月  17 12:19 id_rsa
-rw-r--r-- 1 nvidia nvidia  401 1月  17 12:19 id_rsa.pub
-rw-r--r-- 1 nvidia nvidia  444 1月  17 12:13 known_hosts