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]-----+