ssh-keygen命令来自英文词组SSH key generate的缩写，其功能是生成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 对象

常用参数：

-b	设置密钥长度		-N	设置新密码
-B	显示密钥文件摘要		-p	设置私钥文件的密码
-c	设置注释信息		-P	提供旧密码
-e	读取已有密钥文件		-q	静默执行模式
-f	设置保存密钥的文件名		-r	显示指定公钥文件
-F	设置搜索的主机名		-t	设置要创建的密钥类型
-i	读取SSHv2兼容格式的未加密文件		-v	显示执行过程详细信息
-I	显示指定公钥文件的指纹信息

参考示例

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]-----+