ssh-keygen -t rsa -C www1707 -f filename -P 123456 

-t rsa 设置加密类型
-C www1707 设置标注
-f filename 定义生成的文件名称
-P 123456 用密码123456加密私钥

[root@centos66 ~]# ssh-keygen -t rsa -C www1707 -f filename -P 123456                          
Generating public/private rsa key pair.
Your identification has been saved in filename.
Your public key has been saved in filename.pub.
The key fingerprint is:
82:4b:49:83:c9:6a:25:83:c8:e3:fa:63:b0:2e:38:31 www1707
The key's randomart p_w_picpath is:
+--[ RSA 2048]----+
|                 |
|+. o             |
|o=+.o            |
|..=. +           |
|.o  + . S        |
|E  . . .         |
|o=  .            |
|=.o              |
|o+..             |
+-----------------+
[root@centos66 ~]# ll
total 12
-rw-------. 1 root root  1743 Jul 29 23:34 filename
-rw-r--r--. 1 root root   389 Jul 29 23:34 filename.pub

查看私钥文件：

[root@centos66 ~]# cat filename
-----BEGIN RSA PRIVATE KEY-----
Proc-Type: 4,ENCRYPTED
DEK-Info: DES-EDE3-CBC,E59C93328E0C7EF9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-----END RSA PRIVATE KEY-----

查看公钥文件：

[root@centos66 ~]# cat filename.pub 
ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAQEAsaD9gvSVHypRTCjlCw5U1l4M5Qs3N+fojWa6kEleWw+WGEp0NxdW3VdjO9zEhumC7c6yTtuMIBQe6tHnNR/aUFASFIKUAn4qZx8hkyySFg7cGAlJyoPKbOpc0iQqFHeJB36LLLSS/6mhSzu2M5Zz02kC5V7YY2kCaI2qmfByObDXfQk+TdflyIHoMREHUHyhGlZk+JbGkgCme5Dluwwg3Zy/CysHhQubyizsULwIjUv2p/Q+StxX37ZyMaH6+FpEBmDzCcPqzCeNdiKyX5UzzDFcfp1MFlVRdmOGj7cIptPsh+YeLjbOt29CYichl0RZ62Z1UsC4ls5KT/Gaedrl0w== www1707

将生成的公钥文件追加到/root/.ssh/authorized_keys文件中，添加信任关系

[root@centos66 ~]# cat /root/.ssh/authorized_keys
ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAQEAsaD9gvSVHypRTCjlCw5U1l4M5Qs3N+fojWa6kEleWw+WGEp0NxdW3VdjO9zEhumC7c6yTtuMIBQe6tHnNR/aUFASFIKUAn4qZx8hkyySFg7cGAlJyoPKbOpc0iQqFHeJB36LLLSS/6mhSzu2M5Zz02kC5V7YY2kCaI2qmfByObDXfQk+TdflyIHoMREHUHyhGlZk+JbGkgCme5Dluwwg3Zy/CysHhQubyizsULwIjUv2p/Q+StxX37ZyMaH6+FpEBmDzCcPqzCeNdiKyX5UzzDFcfp1MFlVRdmOGj7cIptPsh+YeLjbOt29CYichl0RZ62Z1UsC4ls5KT/Gaedrl0w== www1707

最后将私钥文件 filename 拷贝到需要连接该linux的机器上使用即可，使用时需要输入私钥的加密密码 123456

#########################################################################################

创建密钥对，不加密私钥

[root@localhost .ssh]# ssh-keygen -t rsa -C www1707 -f www1707
Generating public/private rsa key pair.
Enter passphrase (empty for no passphrase): 
Enter same passphrase again: 
Your identification has been saved in www1707.
Your public key has been saved in www1707.pub.
The key fingerprint is:
48:bb:88:50:ce:5d:5f:d3:65:38:89:bc:e3:0f:38:7b www1707
The key's randomart p_w_picpath is:
+--[ RSA 2048]----+
|         . . oo  |
|          o.+o   |
|  .   o   o...   |
| + . o + .o.     |
|. o . o So .     |
| . . . .o o      |
|  . . .  o o     |
|        . E .    |
|         .       |
+-----------------+
[root@localhost .ssh]# ll
-rw-------. 1 root root 1675 Jul 30 15:43 www1707
-rw-r--r--. 1 root root  389 Jul 30 15:43 www1707.pub
[root@localhost .ssh]# cat www1707
-----BEGIN RSA PRIVATE KEY-----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-----END RSA PRIVATE KEY-----

给不带密码的私钥添加密码123456

[root@localhost .ssh]# ssh-keygen -p -N 123456 -f www1707
Key has comment 'www1707'
Your identification has been saved with the new passphrase.
[root@localhost .ssh]# cat www1707
-----BEGIN RSA PRIVATE KEY-----
Proc-Type: 4,ENCRYPTED
DEK-Info: DES-EDE3-CBC,F1A9E5C1E0574BC2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-----END RSA PRIVATE KEY-----

给加密的私钥更换密码为654321

[root@localhost .ssh]# ssh-keygen -p -P 123456 -N 654321 -f www1707
Key has comment 'www1707'
Your identification has been saved with the new passphrase.
[root@localhost .ssh]# cat www1707
-----BEGIN RSA PRIVATE KEY-----
Proc-Type: 4,ENCRYPTED
DEK-Info: DES-EDE3-CBC,45E3FD5100382745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-----END RSA PRIVATE KEY-----