SSH不对称密钥自动登入服务器

1、先在自己的电脑上创建密钥对

ssh-keygen -t rsa

Windows下生成SSH密钥

$ ssh-keygen -t rsa -C "youremail@example.com"

这时可以在主机A上看到生成的秘钥~/.ssh/idrsa 和公钥 ~/.ssh/ idrsa.pub

2、把公钥放传输到服务器上

第一步是以安装Ubuntu 22.04时创建的用户名和密码登入服务器。

我们用最优秀的跨平台SSH客户端，在windows store里直接下载

新建一个Host，配置如下：

新的服务器，用这条命令给root账户设置密码

sudo passwd root

然后切换到root账户登入


su root

去修改root用户的SSH公钥配置

cd /root

cd .ssh

vi authorized_keys

把自己的公钥贴到上述文件，保存后退出vi编辑器

wq!

上述一堆命令的效果图如下：

3、使用客户端工具免密密码登入

上述演示基于从ubuntu.com官方网站下载的iso映像，全新安装的Ubuntu 22.04服务器。如果不是这样的服务器环境，可能您还需要继续往下看：

4、修改ssh服务配置文件

sudo vi /etc/ssh/sshd_config

- 要检查的几个选项：

PermitRootLogin yes #允许root登录

PermitEmptyPasswords yes #允许空密码登录

PasswordAuthentication yes # 设置是否使用口令验证。

5、重新启动SSH服务

service sshd start 开启ssh服务

service sshd stop 停止ssh服务

service sshd restart 重启ssh服务

6、SSH命令的两个重要开关

1）-i，用途是指定私钥的文件路径

2）-vT，用途是输出详细的信息

PS C:\Users\David> ssh -i X:\gitlab-runner\ssh\id_rsa great@proget.abcdefg.cn -vT

OpenSSH_for_Windows_8.6p1, LibreSSL 3.4.3

debug1: Authenticator provider $SSH_SK_PROVIDER did not resolve; disabling

debug1: Connecting to proget.abcdefg.cn [47.106.133.5] port 22.

debug1: Connection established.

debug1: identity file X:\\gitlab-runner\\ssh\\id_rsa type 0

debug1: identity file X:\\gitlab-runner\\ssh\\id_rsa-cert type -1

debug1: Local version string SSH-2.0-OpenSSH_for_Windows_8.6

debug1: Remote protocol version 2.0, remote software version OpenSSH_8.9p1 Ubuntu-3ubuntu0.1

debug1: compat_banner: match: OpenSSH_8.9p1 Ubuntu-3ubuntu0.1 pat OpenSSH* compat 0x04000000

debug1: Authenticating to proget.abcdefg.cn:22 as 'great'

debug1: load_hostkeys: fopen C:\\Users\\David/.ssh/known_hosts2: No such file or directory

debug1: load_hostkeys: fopen __PROGRAMDATA__\\ssh/ssh_known_hosts: No such file or directory

debug1: load_hostkeys: fopen __PROGRAMDATA__\\ssh/ssh_known_hosts2: No such file or directory

debug1: SSH2_MSG_KEXINIT sent

debug1: SSH2_MSG_KEXINIT received

debug1: kex: algorithm: curve25519-sha256

debug1: kex: host key algorithm: ssh-ed25519

debug1: kex: server->client cipher: chacha20-poly1305@openssh.com MAC: <implicit> compression: none

debug1: kex: client->server cipher: chacha20-poly1305@openssh.com MAC: <implicit> compression: none

debug1: expecting SSH2_MSG_KEX_ECDH_REPLY

debug1: SSH2_MSG_KEX_ECDH_REPLY received

debug1: Server host key: ssh-ed25519 SHA256:g+AgPHqhDZhgIE0yiuMlkIEQfefGlSSO4jeWM8Ekd5A

debug1: load_hostkeys: fopen C:\\Users\\David/.ssh/known_hosts2: No such file or directory

debug1: load_hostkeys: fopen __PROGRAMDATA__\\ssh/ssh_known_hosts: No such file or directory

debug1: load_hostkeys: fopen __PROGRAMDATA__\\ssh/ssh_known_hosts2: No such file or directory

debug1: Host 'proget.abcdefg.cn' is known and matches the ED25519 host key.

debug1: Found key in C:\\Users\\David/.ssh/known_hosts:1

debug1: rekey out after 134217728 blocks

debug1: SSH2_MSG_NEWKEYS sent

debug1: expecting SSH2_MSG_NEWKEYS

debug1: SSH2_MSG_NEWKEYS received

debug1: rekey in after 134217728 blocks

debug1: pubkey_prepare: ssh_get_authentication_socket: No such file or directory

debug1: Will attempt key: X:\\gitlab-runner\\ssh\\id_rsa RSA SHA256:6QNUIUX5zptZfoIHVWBJW8slxrzUsCwMojRe4vo3Fnk explicitdebug1: SSH2_MSG_EXT_INFO received

debug1: kex_input_ext_info: server-sig-algs=<ssh-ed25519,sk-ssh-ed25519@openssh.com,ssh-rsa,rsa-sha2-256,rsa-sha2-512,ssh-dss,ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,sk-ecdsa-sha2-nistp256@openssh.com,webauthn-sk-ecdsa-sha2-nistp256@openssh.com>

debug1: kex_input_ext_info: publickey-hostbound@openssh.com (unrecognised)

debug1: SSH2_MSG_SERVICE_ACCEPT received

debug1: Authentications that can continue: publickey,password

debug1: Next authentication method: publickey

debug1: Offering public key: X:\\gitlab-runner\\ssh\\id_rsa RSA SHA256:6QNUIUX5zptZfoIHVWBJW8slxrzUsCwMojRe4vo3Fnk explicit

debug1: Authentications that can continue: publickey,password

debug1: Next authentication method: password

great@proget.abcdefg.cn's password:

PS C:\Users\David>

7、远程服务器.ssh权限问题

远程服务器~/.ssh文件夹及其文件权限不对，包括

1、~./ssh/authorized_keys文件权限

2、~/.ssh文件夹权限

3、~/.ssh文件夹所有权

Solution

通过其它方式登录到远程服务器，如果是阿里云则可以在网页中通过验证之后打开一个终端，然后进行如下操作

7.1、更改文件所有权

$ chown -R your_user:your_group ~/.ssh

//我用root登录，your_user是root

7.2、更改.ssh文件夹权限

$ chmod 700 ~/.ssh

7.3、更改.ssh/authorized_keys文件权限

$ chmod 600 ~/.ssh/authorized_keys

第7段是拷贝自这个作者：

作者：delta1037

链接：https://www.jianshu.com/p/14027e35b900

来源：简书

著作权归作者所有。商业转载请联系作者获得授权，非商业转载请注明出处。

暂时总结这么多。