openssh-sftp-server - 1:8.4p1-5+deb11u3 main

This is the portable version of OpenSSH, a free implementation of
the Secure Shell protocol as specified by the IETF secsh working
group.
.
Ssh (Secure Shell) is a program for logging into a remote machine
and for executing commands on a remote machine.
It provides secure encrypted communications between two untrusted
hosts over an insecure network. X11 connections and arbitrary TCP/IP
ports can also be forwarded over the secure channel.
It can be used to provide applications with a secure communication
channel.
.
This package provides the SFTP server module for the SSH server. It
is needed if you want to access your SSH server with SFTP. The SFTP
server module also works with other SSH daemons like dropbear.
.
OpenSSH's sftp and sftp-server implement revision 3 of the SSH filexfer
protocol described in:
.
http://www.openssh.com/txt/draft-ietf-secsh-filexfer-02.txt
.
Newer versions of the draft will not be supported, though some features
are individually implemented as extensions.