Steps for ssh jailing

1. Create a user for jailing environment and set password if user doesn't exist.
   
   #useradd -m testuser
   #passwd testuser 

2. Create a Directory Structure for Secure environment.
   
   ( In our case we are creating secure environment in /home directory. You can change it according to requirement)
   #cd /home
   #mkdir -p secure/home
   #cd /home/secure/home
   #mkdir testuser
   #chown testuser:testuser testuser
   
   

3. Enable commands for the user in chrooted environment.
   
   #cp -pr /bin /home/secure/
   #cp -fr /lib /home/secure/
   #cp -fr /lib64 /home/secure/
   #mkdir /home/secure/usr
   #cp -pr /usr/lib /home/secure/usr/
   #cp -pr /usr/bin /home/secure/usr/
   #mkdir -p /home/secure/etc/
   #cp -p /etc/environment /home/secure/etc/ 

4. Configuration for jailing.
   
   Edit the file sshd_config
   #vi /etc/ssh/sshd_config
   
     #SSH JAILING                     
     Match User testuser
     chrootdirectory /home/secure
     #ForceCommand internal-sftp   (If you uncomment this line it will restrict ssh connection and  only sftp connections will be allowed )
   
   

5. # service sshd reload 
   
   

6. After logging in from another server /home/secure will become your / partition over ssh connection.

           #ssh testuser@<ip>

Chroot Configuration for Group:

1. Suppose there are multiple users which needs to be restricted using chroot. 
   Then create a group chroot and add users to the group
    #groupadd chroot
    #usermod -aG chroot testuser
   

2. change sshd config like given below
    #SSH JAILING                     
    Match Group chroot 
    chrootdirectory /home/secure 
      #ForceCommand internal-sftp (If you uncomment this line it will restrict ssh connection and  only sftp connections will be allowed ) # service sshd reload 

3. # service sshd reload 

Things to remember:

1. The chroot directory should alway have root ownership and permission 755 
   otherwise you will get below error
   packet_write_wait: Connection to x.x.x.x port 22: Broken pipe
    

2. Don't forget to copy /etc/environment
   otherwise you will get below error while changing shell to bash
   bash: warning: setlocale: LC_ALL: cannot change locale (en_US.UTF-8)