文章目录
- 1.命令简介
- 2.命令格式
- 3.选项说明
- 4.常用示例
- 参考文献
1.命令简介
ssh-keygen 是 OpenSSH 身份验证密钥实用工具。
ssh-keygen 用于 OpenSSH 身份验证密钥的生成、管理和转换，它支持 RSA 和 DSA 两种认证密钥。
2.命令格式
代码语言：javascript复制ssh-keygen [OPTIONS] <file>...3.选项说明
代码语言：javascript复制-b <bits>
指定密钥长度。
-e
读取 OpenSSH 的私钥或者公钥文件。
-C
添加注释。
-f <filename>
指定用来保存密钥的文件名。
-i
读取未加密的 ssh-v2 兼容的私钥/公钥文件，然后在标准输出设备上显示 openssh 兼容的私钥/公钥。
-l
显示公钥文件的指纹数据。
-N
提供一个新密语。
-P <passphrase>
提供（旧）密语。
-q
静默模式。
-t
指定要创建的密钥类型。4.常用示例
（1）创建一个默认密钥。
代码语言：javascript复制ssh-keygen
Generating public/private rsa key pair.
Enter file in which to save the key (/home/lighthouse/.ssh/id_rsa):
Enter passphrase (empty for no passphrase):
Enter same passphrase again:
Your identification has been saved in /home/lighthouse/.ssh/id_rsa.
Your public key has been saved in /home/lighthouse/.ssh/id_rsa.pub.
The key fingerprint is:
SHA256:c8jkpkXgRqqfelFHKxq956d 6qYzAR0kHgnaVs9gtYw lighthouse@VM-0-3-centos
The key's randomart image is:
---[RSA 2048]----
| ..* = |
| o .%.o. |
|. o EoBoo. |
| . .o.==o. |
| . = S . |
| .o.o .o |
| o.. |
| .. o o o |
| .. .B== |
----[SHA256]----- 中途需要三次确认，全部缺省直接回车即可。在当前用户的家目录下，~/.ssh 目录下将会看到三个文件：
代码语言：javascript复制ls -l ~/.ssh
authorized_keys id_rsa id_rsa.pub如果当前主机是 SSH 服务端，那么会有 authorized_keys，用来存放客户端机器的公钥。
id_rsa 为当前主机的私钥。
id_rsa.pub 为当前主机的公钥。
我们需要本地机器通过 SSH 访问远程服务器时为了减少输入密码的步骤，基本上都会在本地机器生成 SSH 公钥，然后将本地 SSH 公钥复制到远程服务器的 .ssh/authorized_keys 中，这样就可以免密登录了。
如果当前主机为客户端，你可能还会在 ~/.ssh 目录下看到 known_hosts 文件，该文件用来记录连接过的远程主机。如果是首次连接某个远程主机，那么会有安全提示，是否继续连接。
（2）指定要创建的密钥类型，缺省为 RSA。
代码语言：javascript复制ssh-keygen -t rsa
Generating public/private rsa key pair.
Enter file in which to save the key (/root/.ssh/id_rsa):
/root/.ssh/id_rsa already exists.
Overwrite (y/n)? y
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:nTaoqOxlG6IQQ2zDTMvSk2EON 4tLrYqPy7IBrstoy4 root@localhost.localdomain
The key's randomart image is:
---[RSA 2048]----
|..= |
|*B. |
|.X* |
| ..o o . |
|o o . S = |
|. . . . . . |
|*oo = . |
|EBo= o |
|%@B.. |
----[SHA256]----- （3）指定密钥的类型并添加注释。
代码语言：javascript复制ssh-keygen -t rsa -C "dablelv@qq.com"
Generating public/private rsa key pair.
Enter file in which to save the key (/root/.ssh/id_rsa):
/root/.ssh/id_rsa already exists.
Overwrite (y/n)? y
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:Wx3MWwj36fwhcnb6hjdIIJ3SUggCLcmFq62Earqy2E0 deng@qq.com
The key's randomart image is:
---[RSA 2048]----
| ..*o .. o . |
| = .. . * o . |
| o * |
| . * * |
|. o S =. oo |
|.o . o . ..|
|o . E . ..o .|
| o o. |
|Oo. . o..|
----[SHA256]----- （4）读取 OpenSSH 的私钥或者公钥文件。
代码语言：javascript复制ssh-keygen -e
---- BEGIN SSH2 PUBLIC KEY ----
Comment: "2048-bit RSA, converted by lighthouse@VM-0-3-centos from Ope"
AAAAB3NzaC1yc2EAAAADAQABAAABAQDb1aKBbvfSefnuzLfhNKlIa4zsbBFG m7ugZbeBW
RwJXONhSq/AW27 Tq9zDtI6qG UxmjIorVHbAVl4llVZz8e5b/s5I0yiBoLy/RokpvisNB
kVkWl2oNGtkdHxTSYcJ3jdbTZ ya6MyOiaMt24jV zxxS1BXWxA14kS/JqiMC7lx9Vu0Ed
AHY0zq2dj pX31FB7Xs7p98eO Est6msCGIInIpzGTlTskL6m7B aMBaquWlEyQAmRX5G8
YoOFw aDT4q1aaaaBkFdcy/nhHPpbfM8eIzbAv khHRjZV8XQCo UeHzme8nmfWDCWwKZ8
TnpO239diTdl2Wps2YCMex
---- END SSH2 PUBLIC KEY ----（5）安静模式生成密钥对。
代码语言：javascript复制ssh-keygen -q -t rsa
Enter file in which to save the key (/home/lighthouse/.ssh/id_rsa):
/home/lighthouse/.ssh/id_rsa already exists.
Overwrite (y/n)? y
Enter passphrase (empty for no passphrase):
Enter same passphrase again:参考文献
ssh-keygen(1) — Linux manual page - man7.org 一文读懂authorized_keys和known_hosts_游语的博客-CSDN博客
