|
Size: 2036
Comment:
|
Size: 2293
Comment:
|
| Deletions are marked like this. | Additions are marked like this. |
| Line 1: | Line 1: |
| = SSH = | = OpenSSH = |
| Line 3: | Line 3: |
| '''Secure Shell''' ('''SSH''') is a protocol that enables remote access to a server. This is primarily a Linux and BSD feature, with Windows systems preferring access by [[RemoteDesktopProtocol|RDP]]. The most common implementation is the '''OpenSSH''' project. | '''OpenSSH''' is a [[Encryption/SSH|SSH]] client and server. |
| Line 5: | Line 5: |
| The server-side service is `sshd(8)`, while there are various client-side programs such as `ssh(1)` or PuTTY. | OpenSSH is widely deployed on [[Linux]] and [[BSD]] operating systems, with Windows systems preferring access by [[Protocols/RDP|RDP]]. The service is `sshd(8)` and the utility is `ssh(1)`. |
| Line 15: | Line 17: |
| Most [[Linux]] and [[BSD]] distributions will have `ssh(1)` and `sshd(8)` installed. Otherwise, they will be available in an `openssl` package. | |
| Line 16: | Line 19: |
=== Client === If necessary, install `openssh`. Most Linux and BSD distributions will include it by default. On Windows, try PuTTY and hope it works. === Server === Many Linux distributions have `openssh` installed and `sshd(8)` running by default. This is especially true of ISOs meant for server boxes. |
Furthermore, many Linux distributions have `sshd(8)` running by default. |
| Line 31: | Line 23: |
| For `init`-based systems, try `service sshd enable` or setting the following in `/etc/rc.conf`: | For OpenRC-based systems, [[Linux/OpenRC|start and add]] the `sshd` service. For BSDs, [[BSD/Init|start]] the `sshd` service. To have it automatically start on boot, try editing `/etc/rc.conf` like: |
| Line 41: | Line 35: |
| == Configuration == | == Setup == |
| Line 85: | Line 79: |
| ---- == Usage == The primary use of `ssh(1)` is to access a remote host: {{{ ssh [email protected] }}} See [[Encryption/OpenSSH/Tunnels|here]] for details on creating and using SSH tunnels. ---- == See also == [[https://man.archlinux.org/man/core/openssh/ssh.1.en|ssh(1)]] [[https://man.archlinux.org/man/core/openssh/sshd.8.en|sshd(8)]] |
OpenSSH
OpenSSH is a SSH client and server.
OpenSSH is widely deployed on Linux and BSD operating systems, with Windows systems preferring access by RDP.
The service is sshd(8) and the utility is ssh(1).
Installation
Most Linux and BSD distributions will have ssh(1) and sshd(8) installed. Otherwise, they will be available in an openssl package.
Furthermore, many Linux distributions have sshd(8) running by default.
For systemd(1)-capable systems, start and enable sshd.service.
For OpenRC-based systems, start and add the sshd service.
For BSDs, start the sshd service. To have it automatically start on boot, try editing /etc/rc.conf like:
sshd_enable="YES"
Setup
Require Authentication by Key
To require that all client logins use keys, use:
PubkeyAuthentication yes AuthorizedKeysFile .ssh/authorized_keys PasswordAuthentication no
To make an exception for a user, add at the bottom of the file:
Match User git PasswordAuthentication yes Match all
To make an exception for the local network, add (also at the bottom of the file):
Match Address 192.168.*.* PasswordAuthentication yes Match all
Login Messages
Usually any messages printed on login are actually handled by PAM. This can be tricky to configure, so instead disable the default login messages and configure the shell profile to print the desired messages.
To disable all PAM login messages for a user, try:
touch ~/.hushlogin
Note that default PAM configurations print /etc/motd and the output of /usr/bin/lastlog --user USERNAME on login.
Usage
The primary use of ssh(1) is to access a remote host:
ssh [email protected]
See here for details on creating and using SSH tunnels.