$ ssh-host-config
*** Info: Generating missing SSH host keys
*** Query: Overwrite existing /etc/ssh_config file? (yes/no) yes
*** Info: Creating default /etc/ssh_config file
*** Query: Overwrite existing /etc/sshd_config file? (yes/no) yes
*** Info: Creating default /etc/sshd_config file
*** Info: StrictModes is set to 'yes' by default.
*** Info: This is the recommended setting, but it requires that the POSIX
*** Info: permissions of the user's home directory, the user's .ssh
*** Info: directory, and the user's ssh key files are tight so that
*** Info: only the user has write permissions.
*** Info: On the other hand, StrictModes don't work well with default
*** Info: Windows permissions of a home directory mounted with the
*** Info: 'noacl' option, and they don't work at all if the home
*** Info: directory is on a FAT or FAT32 partition.
*** Query: Should StrictModes be used? (yes/no) yes
*** Info: Privilege separation is set to 'sandbox' by default since
*** Info: OpenSSH 6.1.  This is unsupported by Cygwin and has to be set
*** Info: to 'yes' or 'no'.
*** Info: However, using privilege separation requires a non-privileged account
*** Info: called 'sshd'.
*** Info: For more info on privilege separation read /usr/share/doc/openssh/README.privsep.
*** Query: Should privilege separation be used? (yes/no) no
*** Info: Updating /etc/sshd_config file
*** Query: Do you want to install sshd as a service?
*** Query: (Say "no" if it is already installed as a service) (yes/no) yes
*** Query: Enter the value of CYGWIN for the daemon: [] ntsec
*** Info: On Windows Server 2003, Windows Vista, and above, the
*** Info: SYSTEM account cannot setuid to other users -- a capability
*** Info: sshd requires.  You need to have or to create a privileged
*** Info: account.  This script will help you do so.
*** Info: It's not possible to use the LocalSystem account for services
*** Info: that can change the user id without an explicit password
*** Info: (such as passwordless logins [e.g. public key authentication]
*** Info: via sshd) when having to create the user token from scratch.
*** Info: For more information on this requirement, see
*** Info: https://cygwin.com/cygwin-ug-net/ntsec.html#ntsec-nopasswd1
*** Info: If you want to enable that functionality, it's required to create
*** Info: a new account with special privileges (unless such an account
*** Info: already exists). This account is then used to run these special
*** Info: servers.
*** Info: Note that creating a new user requires that the current account
*** Info: have Administrator privileges itself.
*** Info: No privileged account could be found.
*** Info: This script plans to use 'cyg_server'.
*** Info: 'cyg_server' will only be used by registered services.
*** Query: Do you want to use a different name? (yes/no) no
*** Query: Create new privileged user account 'HOUZHIWEI-PC\cyg_server' (Cygwin name: 'cyg_server')? (yes/no) yes
*** Info: Please enter a password for new user cyg_server.  Please be sure
*** Info: that this password matches the password rules given on your system.
*** Info: Entering no password will exit the configuration.
*** Query: Please enter the password:
*** Query: Reenter:
*** Info: User 'cyg_server' has been created with password 'victorho'.
*** Info: If you change the password, please remember also to change the
*** Info: password for the installed services which use (or will soon use)
*** Info: the 'cyg_server' account.
*** Info: The sshd service has been installed under the 'cyg_server'
*** Info: account.  To start the service now, call `net start sshd' or
*** Info: `cygrunsrv -S sshd'.  Otherwise, it will start automatically
*** Info: after the next reboot.
*** Info: Host configuration finished. Have fun!

[huqiu@101 .ssh]$ ssh-keygen -f test   -C "test key"
                             # ~~文件名   ~~~~ 备注（comment）

[huqiu@101 .ssh]$ ssh-keygen
Generating public/private rsa key pair.
Enter file in which to save the key (/home/huqiu/.ssh/id_rsa):

[huqiu@101 .ssh]$ ssh-keygen -t rsa -f test -C "test key"
Generating public/private rsa key pair.
Enter passphrase (empty for no passphrase):
Enter same passphrase again:

[huqiu@101 .ssh]$ ll test*
-rw------- 1 huqiu huqiu 1675 Sep 15 13:24 test
-rw-r--r-- 1 huqiu huqiu  390 Sep 15 13:24 test.pub

[huqiu@101 .ssh]$ cat test.pub
ssh-rsa
AAAAB3NzaC1yc2EAAAABIwAAAQEAlgjiMw7AskxbvpQY9rmZPQxQBzh9laxFvbaini2EgmQkNsXBA9WJOXn2YBJauoiVsdUKBWA97avjsobrTxsCYvFr1yQQvTfTlbqlqGNIhQc/3HjTl2pIkClpDWvBrRN+jpyESS4MNbfOL1qjT4c/QhGvj6U6HrN6kUyn58oyyJpTzOLG74AZELJ2Led57QvTw1yJXZuAMWioR0A3BGd25fdocLX3ebux6ya8AsloOVYfsAqGlggrARe6FXjLfMH4a/nxaAdiDYVXU/Vr1ybK9P7SfyEDGJi3JtgiPUlA6vPxUC
E+9IJPQaqqeqCGzrJ6G/XO7om1v9YLLG/H/ZN2tQ== test key         # ~~~~备注

D:\Program Files\ConsoleZ>ssh-keygen -t rsa
Generating public/private rsa key pair.
Enter file in which to save the key (/home/houzhiwei/.ssh/id_rsa):
Enter passphrase (empty for no passphrase):
Enter same passphrase again:
Your identification has been saved in /home/houzhiwei/.ssh/id_rsa.
Your public key has been saved in /home/houzhiwei/.ssh/id_rsa.pub.
The key fingerprint is:
SHA256:mclUKbp4BzSf7pMP6+iB55xOzgLIj79gHc+9eF1gsR0 houzhiwei@houzhiwei-PC
The key's randomart image is:
+---[RSA 2048]----+
|          ..     |
|      o .o.E     |
|     . +.o+ .    |
|      oooB .     |
|.. . . +S .      |
|..o =.+ o  .     |
| ooo.+++o..      |
|.....B.==+       |
|  .o.=@ooo.      |
+----[SHA256]-----+
D:\Program Files\ConsoleZ>

houzw@houzw-PC ~/.ssh
$ ssh-copy-id -i ~/.ssh/id_rsa_centos.pub houzw@192.168.1.109
/usr/bin/ssh-copy-id: INFO: Source of key(s) to be installed: "/home/houzw/.ssh/id_rsa_centos.pub"
The authenticity of host '192.168.1.109 (192.168.1.109)' can't be established.
ECDSA key fingerprint is SHA256:kCnXmyP9B/4nm+OLG5Nm6NiFOgg2YO3kkjPq3aS08yo.
Are you sure you want to continue connecting (yes/no)? yes
/usr/bin/ssh-copy-id: INFO: attempting to log in with the new key(s), to filter out any that are already installed
/usr/bin/ssh-copy-id: INFO: 1 key(s) remain to be installed -- if you are prompted now it is to install the new keys
houzw@192.168.1.109's password:
Number of key(s) added: 1
Now try logging into the machine, with:   "ssh 'houzw@192.168.1.109'"
and check to make sure that only the key(s) you wanted were added.

$ ssh username@www-03.nixcraft "umask 077; mkdir .ssh"
$ cat $HOME/.ssh/id_rsa.pub | ssh username@www-03.nixcraft "cat >> .ssh/authorized_keys"

houzw@houzw-PC ~/.ssh
$ ssh-keygen -R 192.168.1.109
# Host 192.168.1.109 found: line 3
/home/houzw/.ssh/known_hosts updated.
Original contents retained as /home/houzw/.ssh/known_hosts.old

cygrunsrv --stop sshd # 或 net stop sshd
cygrunsrv --remove sshd # 或 cygrunsrv --R sshd

# sotp sshd
net stop sshd
# 刪除 cygwin
sc delete sshd
# 刪除帳號 sshd cyg_server
net user sshd /del
net user cyg_server /del
#
takeown /f C:\cygwin /r /d y
icacls c:\cygwin /t /grant everyone:F
# 刪除檔案目錄
rmdir /s /q c:\cygwin