阿里云ECS利用密钥对ssh登录服务器

1.在服务机上操作

创建要远程登录的用户和密码

[root@izwz97s23bov6qmem6poj8z ~]# useradd jundong
[root@izwz97s23bov6qmem6poj8z ~]# passwd jundong
New password:
Retype new password:
passwd: all authentication tokens updated successfully.

2.在客户机上操作（其他机器也行，主要是用来创建密钥对）

2.1.创建ssh-key

[root@node1 ~]# ssh-keygen
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:
SHA256:W05lCKLqZ8FWTyAwTsUrBzg7HRzZfZ8ZbacHg/Wnf6c root@node1
The key's randomart image is:
+---[RSA 2048]----+
| o=Bo.o .  +.    |
|oo=.oo.o..o.=..  |
| +.o.......=o=. .|
|o ooo. o  +o. .o |
| ..o+   S o  ..  |
| . . .   =     . |
|  . o   . .     +|
|   o           .o|
|              E  |
+----[SHA256]-----+

2.2.把生成的的秘钥拷贝到服务器，

两种可选方式

方式一：可以手动拷贝

手动拷贝刚刚生成的公钥id_rsa.pub（在当前用户家目录的.ssh/id_rsa.pub），将里面的内容追加到要登录的服务器的目标用户家目录下的.ssh/ authorized_keys中，这里是/home/jundong.ssh/ authorized_keys

方式二：直接用命令拷贝

ssh-copy-id可以方便快捷地把公钥追加到到服务端的authorized_keys文件中,注意用户名，输入密码

ssh-copy-id [email protected]

[root@node1 ~]# ssh-copy-id [email protected]
/usr/bin/ssh-copy-id: INFO: Source of key(s) to be installed: "/root/.ssh/id_rsa.pub"
The authenticity of host '120.78.150.47 (120.78.150.47)' can't be established.
ECDSA key fingerprint is SHA256:KwfKwzN4xqw7/VxoVw5IoTi0NhUPZ+h2fSQXi3zgXXY.
ECDSA key fingerprint is MD5:22:b0:8e:c0:21:e6:96:b1:de:bd:bd:c4:08:d9:bf:4d.
Are you sure you want to continue connecting (yes/no)? yes
/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
[email protected]'s password:

Number of key(s) added: 1

Now try logging into the machine, with:   "ssh '[email protected]'"
and check to make sure that only the key(s) you wanted were added.

方式三：在阿里云控制台导入

【在控制台导入证书，阿里云做的事是：将公钥追加到/root/.ssh/authorized_keys中；修改/etc/ssh/sshd_config,把PasswordAuthentication改成no】

1.这种方式会默认把密码登录禁用，只能使用秘钥登录，可以自己手动打开（修改/etc/ssh/sshd_config,把PasswordAuthentication改成yes）

2.这种方式只能使用root用户登录，其他用户不能使用这种方式导入，因为控制台导入只会导入到/root/.ssh/authorized_keys，不会导入到其他用户目录

复制刚刚生成的公钥id_rsa.pub（在当前用户家目录的.ssh/id_rsa.pub），这里是/home/jundong.ssh/ authorized_keys，粘贴到控制台的文本框确定即可，再将密钥对绑定到指定服务器

参考链接：https://help.aliyun.com/document_detail/51794.html?spm=5176.doc51793.6.707.1A6GMv

3.1在生成秘钥那台客户机上

[root@node1 ~]# ssh [email protected]

Welcome to Alibaba Cloud Elastic Compute Service !

[jundong@izwz97s23bov6qmem6poj8z ~]$

3.2在其他工具上

拷贝生成的秘钥对的私钥/home/jundong/.ssh/id_rsa（在当前用户家目录的.ssh/id_rsa）到你想要用来登录的客户机，指定其为登录的私钥和对应的用户名即可

提示使用密钥文件登录了

windows下其他工具应该也是类似的

【推荐使用Linux下自带的ssh-keygen工具生成公钥和私钥，这样的证书是通用的。在putty或者secureCRT生成的证书会是其他格式或者是带有工具特有的信息，这些证书可能在其他工具无法使用，例如：在SecureCRT生成的证书，putty可能就不能用了】