SFTP or SSH File Transfer Protocol is a network protocol that provides file transfer functionality over a secure and reliable data stream. This protocol was designed by Internet Engineering Task Force or IETF and it can be used with SSH version 2.0. The protocol assumes that it is running over a secure channel like SSH, the client is authenticated by the server and the server already has the identity information of the client. In this article, we are going to discuss how the SFTP protocol works.

• How does the SFTP protocol work?

  • Protocol Initialization

  • Requests from the Client to the Server

    • Opening and Closing Files and Directories

    • Reading or Writing Files

    • Reading Directories

    • Removing Files and Renaming Files or Directories

    • Creating and Deleting Directories

    • Retrieving File Attributes

    • Setting File Attributes

    • Creating or Reading a Link

    • Obtaining or Releasing a Byte Range Lock

  • Responses from the Server to the Client