===== SSH =====

==== generating keys, setting up config, basic and usefull commands ====

{{ https://upload.wikimedia.org/wikipedia/en/6/65/OpenSSH_logo.png }}

What's up folks! Markiplier here, I will show you how to work with SSH for different systems. I don't have any expirience with Apple software but it should handle the same as Linux I will mention if Windows needs special attention.

SSH stands for **S**ecure **Sh**ell. It's used most commonly for connecting to servers/computers. It was a replacement for Telnet, which is plaintext, while SSH uses stronk encryption. The most common SSH is OpenBSD's OpenSSH, but there are alternatives like Dropbear.

Everything written inside //<brackets should be replaced, with them included>// I will write ''$'' if user can write a command and ''#'' if you need elevated privileges like with sudo/doas/root/admin

if you want to connect to a server, write in your shell\\  ''$ **ssh** //<user>//**@**//<ip or domain>//''

There flags that you should know

^ flag  ^ what is it for ^
| ''-p''                   | for port |
| ''-i <your private key'' | include key |
| ''-v'' | verbose, if you need more info on what is happening during connection and breaking it |
| ''-R <server port>:localhost:<client port>'' | port forwarding from __server__ to client |
| ''-L <client port>:localhost:<server port>'' | port forwarding from client to __server__ |
| ''-N'' | do not execute any commands, useful for port forwarding |
| ''-f'' | run ssh in background after auth, also useful for port forwarding |
| ''-P'' | for port in scp |

=== How to simplify connections ===
You can create ''config'' file in your .ssh folder, it's located in your /home/<user> directory, or /root or in C:\Users\<user> in case of Windows

<code - config>
Host <your chosen name>
  Hostname <your IP/domain>
  User <your username>
  IdentityFile <path to private SSH key>
  Port <port opened for SSH>
</code>

You have way more settings to work with so look them up and have fun! Flags mentioned above can be also set in ''~/.ssh/config'' //(with appropriate keywords)//

How does my machine become a server?
In case of Linux and Unix like systems, you should start sshd daemon, like 
''# systemctl enable --now sshd''
It's best to edit ''/etc/ssh/sshd_config'' as sudo/root and change the settings you want.
In general it's best to disable passwords and root login. Just uncomment the line by deleting "#" and write yes/no in appropriate place



=== SSH clients for Windows ===

  * The easiest - Powershell/Terminal
  * [[https://putty.org/index.html|PuTTY]]
  * [[https://termius.com/index.html|Terminus]]
  * [[https://mobaxterm.mobatek.net/|MobaXterm]]

=== Usefull links ===

  * [[https://wiki.archlinux.org/title/OpenSSH|Arch Linux wiki]]
  * [[https://wiki.gentoo.org/wiki/SSH|Gentoo Linux wiki]]
  * [[https://wiki.alpinelinux.org/wiki/Setting_up_a_SSH_server|Alpine Linux wiki]]