What Is FTP over SSL (FTPS)?

FTP is the short term for File Transfer Protocol and SSL is the short term for Secure Sockets Layer. FTPS is the short term for “FTP over SSL”, or file transfer protocol over secure sockets layer.

FTP over SSL (FTPS in short) is a common encrypted file transfer method based on the File Transfer Protocols. Unlike Secure FTP connections is itself encrypted FTP connection without sending any data concerning an underlying SSH connection. Encrypting the control channel and the data channel is through SSL or TLS authentication with a key size possible from up to 256 bits (in this case AES).

Even server-to-server transfers (FXP) can be encrypted using SSL / TLS, but this is far from being standardized, and there are several technical options for implementation (for example SSCN). Thanks to FTP over SSL, it is possible to encrypt an FTP transfer even in passive mode completely.

In the active mode is often used variant of the Implicit SSL, wherein the control channel immediately when the connection is encrypted and is known not only by the plain command AUTH SSL or AUTH TLS, such as (in the variant also FTPES Explicit SSL), have made .

Older FTP clients that do not support FTP over SSL, can be upgraded through the use of corresponding FTP proxy servers “. Today, FTP over SSL is implemented already in many popular FTP clients and FTP servers, the use of SSL is recommended to ensure that no unencrypted usernames, passwords and data can be read by attackers.

Supporting FTP Clients

* Cyberduck: graphical multi-protocol client (OS X (GPL) (available in many languages)
* FlashFXP: FTPS client (Win32)
* FileZilla: SFTP and FTPS client (GPL)
* FireFTP: Firefox extension for FTP and FTPS
* Lftp: FTPS command line client UNIX (GPL)
* SmartFTP: sFTP & FTPS client (Win32)
* Total Commander: File manager in the style of Norton Commander for Windows. Requires OpenSSL for Windows
* WISE-FTP: sFTP & FTPS Client for Windows

Secure FTP

The Secure File Transfer Protocol (or undocumented means of secure file transfer method, in short, is Secure FTP), a network protocol for transferring files over TCP / IP networks. The peculiarity is that an otherwise unsecured file transfer protocol connection (FTP partially) over Secure Shell (SSH) is tunneled.

Secure FTP transfers the authentication of the client to the server and the Exchange and a listing of directories through an encrypted SSH tunnel. The actual data transfer takes place as FTP unencrypted over another, random port, the client and server will negotiate.

If the client for use of the passive mode, and for the use of a SOCKS proxy is configured, and the actual data transfer over the SSH connection will be managed. This mode is provided by many SSH clients.

Secure FTP is easily confused with the SSH File Transfer Protocol (SFTP). However, this is another, from the ground up, developed file transfer protocol based on SCP.

Encryption protocols, both the control channel as well as file transfer, are the aforementioned Secure Copy Protocol (SCP), the SSH File Transfer Protocol (SFTP), the Multi-purpose Business Security over IP (MBS / IP) and the popular FTP over SSL (FTPS).

Study: From Wikipedia, the free encyclopedia. The text is available under the Creative Commons.