ssh-keygen命令 – 生成SSH密钥文件

《Linux就该这么学》是一本基于最新Linux系统编写的入门必读书籍，内容面向零基础读者，由浅入深渐进式教学，销量保持国内第一，年销售量超过10万余本。点此免费在线阅读。

ssh-keygen命令来自于英文词组“SSH key generate”的缩写，其功能是用于生成SSH密钥文件。ssh-keygen命令能够对SSH密钥文件进行生成、管理、转换等工作，支持RSA和DSA两种密钥格式。

语法格式：ssh-keygen [参数]

常用参数：

-b指定密钥长度
-e读取已有私钥或者公钥文件
-f指定用来保存密钥的文件名
-t指定要创建的密钥类型
-C添加注释

参考实例

创建一个SSH密钥文件：

[root@linuxcool ~]# ssh-keygen
Generating public/private rsa key pair.
Enter file in which to save the key (/root/.ssh/id_rsa): 直接回车，以默认路径保存
Created directory '/root/.ssh'.
Enter passphrase (empty for no passphrase): 直接回车，不额外设置密钥密码
Enter same passphrase again: 直接回车，确认不额外设置密钥密码
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:tUB6SjLnvqM7p2l+bmHUZGNqUyyOPmXGyiMp3tC9xNA root@linuxcool.com
The key's randomart image is:
+---[RSA 2048]----+
|       ..        |
|      .oB        |
|    +++Oo..      |
|   ..E@o.o .     |
|  .++Bo.S .      |
|..o.*=o          |
|..o..+o.         |
| . .oo=.         |
|   o*Xo.         |
+----[SHA256]-----+

手动指定加密格式并添加注释信息，创建一个SSH密钥文件

[root@linuxcool ~]# ssh-keygen -t rsa -C "welcome to linuxcool.com"
Generating public/private rsa key pair.
Enter file in which to save the key (/root/.ssh/id_rsa): 直接回车，以默认路径保存
Created directory '/root/.ssh'.
Enter passphrase (empty for no passphrase): 直接回车，不额外设置密钥密码
Enter same passphrase again: 直接回车，确认不额外设置密钥密码
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:OQodor0B83DoxbFOY+KUo0swrQAgo8tL3qIHA0t40gQ welcome to linuxcool.com
The key's randomart image is:
+---[RSA 2048]----+
|E.  .            |
|+o.+ o           |
|*o@ X .          |
|BXo/ + . .       |
|*B+ * . S        |
|B.o  + . .       |
|.* .. .          |
|. o              |
|..               |
+----[SHA256]-----+
Author