Editing Secure Shell (section)

==Use==
{{Original research section|date=June 2024|reason=Most information is original search based on primary sources, there are few secondary sources}}
SSH is typically used to log into a remote computer's [[Shell (computing)|shell]] or [[command-line interface]] (CLI) and to execute commands on a remote server. It also supports mechanisms for [[tunneling protocol|tunneling]], [[Port forwarding|forwarding]] of [[TCP and UDP port|TCP ports]] and [[X11]] connections and it can be used to transfer files using the associated [[SSH file transfer protocol|SSH File Transfer Protocol]] (SFTP) or [[Secure Copy Protocol]] (SCP).<ref name="rfc4252" />

SSH uses the [[client–server model]]. An SSH [[client (computing)|client]] program is typically used for establishing connections to an SSH [[daemon (computing)|daemon]], such as sshd, accepting remote connections. Both are commonly present on most modern [[operating systems]], including [[macOS]], most distributions of [[Linux]], [[OpenBSD]], [[FreeBSD]], [[NetBSD]], [[Solaris (operating system)|Solaris]] and [[OpenVMS]]. Notably, versions of [[Windows]] prior to Windows 10 version 1709 do not include SSH by default, but [[proprietary software|proprietary]], [[freeware]] and [[Open-source software|open source]] versions of various levels of complexity and completeness did and do exist (see [[Comparison of SSH clients]]). In 2018 [[Microsoft]] began porting the [[OpenSSH]] source code to Windows<ref>[https://github.com/PowerShell/Win32-OpenSSH Win-32 OpenSSH]</ref> and in [[Windows 10 version history#Version 1709 (Fall Creators Update)|Windows 10 version 1709]], an official Win32 port of OpenSSH is now available.

File managers for UNIX-like systems (e.g. [[Konqueror]]) can use the [[Files transferred over shell protocol|FISH]] protocol to provide a split-pane GUI with drag-and-drop.  The open source Windows program [[WinSCP]]<ref>{{cite web|url=http://winscp.net/eng/index.php|title=WinSCP home page|url-status=live|archive-url=https://web.archive.org/web/20140217163252/http://winscp.net/eng/index.php|archive-date=2014-02-17}}</ref> provides similar file management (synchronization, copy, remote delete) capability using PuTTY as a back-end.  Both WinSCP<ref>{{cite web|url=http://portableapps.com/apps/internet/winscp_portable|title=WinSCP page for PortableApps.com|url-status=live|archive-url=https://web.archive.org/web/20140216120049/http://portableapps.com/apps/internet/winscp_portable|archive-date=2014-02-16}}</ref> and PuTTY<ref>{{cite web|url=http://portableapps.com/apps/internet/putty_portable|title=PuTTY page for PortableApps.com|url-status=live|archive-url=https://web.archive.org/web/20140216214310/http://portableapps.com/apps/internet/putty_portable|archive-date=2014-02-16}}</ref> are available packaged to run directly off a USB drive, without requiring installation on the client machine. Crostini on [[ChromeOS]] comes with OpenSSH by default. Setting up an SSH server in Windows typically involves enabling a feature in the Settings app.

SSH is important in [[cloud computing]] to solve connectivity problems, avoiding the security issues of exposing a cloud-based virtual machine directly on the Internet. An SSH tunnel can provide a secure path over the Internet, through a firewall to a virtual machine.<ref>{{cite web|last1=Amies|first1=A|last2=Wu|first2=C F|last3=Wang|first3=G C|last4=Criveti|first4=M|year=2012|url=http://www.ibm.com/developerworks/cloud/library/cl-networkingtools/index.html|title=Networking on the cloud|website=IBM developerWorks|url-status=live|archive-url=https://web.archive.org/web/20130614123106/http://www.ibm.com/developerworks/cloud/library/cl-networkingtools/index.html|archive-date=2013-06-14}}</ref>

The [[Internet Assigned Numbers Authority|IANA]] has assigned [[Transmission Control Protocol|TCP]] [[Port (computer networking)|port]] 22, [[User Datagram Protocol|UDP]] port 22 and [[Stream Control Transmission Protocol|SCTP]] port 22 for this protocol.<ref>{{cite web|title=Service Name and Transport Protocol Port Number Registry|url=https://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xhtml}}</ref> IANA had listed the standard TCP port 22 for SSH servers as one of the [[list of well-known ports (computing)|well-known ports]] as early as 2001.<ref>{{cite web|url=https://www.iana.org/assignments/port-numbers|title=Service Name and Transport Protocol Port Number Registry|website=iana.org|url-status=live|archive-url=https://web.archive.org/web/20010604223215/https://www.iana.org/assignments/port-numbers|archive-date=2001-06-04}}</ref> SSH can also be run using [[SCTP]] rather than TCP as the connection oriented transport layer protocol.<ref>{{cite conference|last=Seggelmann|first=R.|author2=Tuxen, M. |author3=Rathgeb, E.P. |title=SSH over SCTP — Optimizing a multi-channel protocol by adapting it to SCTP|conference=8th International Symposium on Communication Systems, Networks & Digital Signal Processing (CSNDSP)|date=18–20 July 2012|pages=1–6|doi=10.1109/CSNDSP.2012.6292659|isbn=978-1-4577-1473-3|s2cid=8415240}}</ref>