CentOS Stream 9

OpenSSH : SFTP only + Chroot2022/01/07

	Configure SFTP only + Chroot. Some users who are applied this setting can access only with SFTP and also applied chroot directory.
[1]	For example, Set [/home] as the Chroot directory.

# create a group for SFTP only

[root@dlp ~]#

groupadd sftp_users

[root@dlp ~]#

vi /etc/ssh/sshd_config

# line 123 : comment out and add a line

#Subsystem      sftp    /usr/libexec/openssh/sftp-server
Subsystem       sftp    internal-sftp

# add to the end

Match Group sftp_users
X11Forwarding no
AllowTcpForwarding no
ChrootDirectory /home
ForceCommand internal-sftp

[root@dlp ~]#

systemctl restart sshd

# for example, set [cent] user as SFTP only user

[root@dlp ~]#

usermod -aG sftp_users cent

[2]	Verify working with a user set SFTP only setting.

[cent@node01 ~]$

ssh dlp.srv.world

Enter passphrase for key '/home/cent/.ssh/id_rsa':
This service allows sftp connections only.
Connection to dlp.srv.world closed.

# denied normally

[cent@node01 ~]$

sftp dlp.srv.world

Enter passphrase for key '/home/cent/.ssh/id_rsa':
Connected to dlp.srv.world.
sftp>

ls -l

drwx------    3 1000     1000           95 Jan  7 02:08 cent

sftp>

pwd

Remote working directory: /
sftp>

exit

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