This tutorial explains how to setup and use an SFTP server on CentOS. Before I start, let me explain what actually SFTP represents and what it is used for. Currently, most people know that we can use normal FTP for transferring, downloading or uploading data from a server to client or client to server. But this protocol is getting hacked easily (if TLS is not used) by anonymous intruders as it the ports are widely open to anyone. Therefore, SFTP has been introduced to as another alternative to meet the main purpose to strengthen the security level.
SFTP stands for SSH File Transfer Protocol or Secure File Transfer Protocol. It uses a separate protocol packaged with SSH to provide a secure connection.
1. Preliminary Note
For this tutorial, I am using CentOS 6.4 in the 32bit version. The same steps will work on CentOS 7 as well. The tutorial result will show how a client can be provided with access to the SFTP server but unable to login to the server itself by SSH.