git/ssh: extended git usage with ssh clone

wiki/linux/ssh.md

@@ -5,17 +5,32 @@ In this article it is assumed that `openssh` is used.
 
 ## Usage
 
-### Generate new keys
+### Generate New Keys
 
 To generate new ssh keys simply run `ssh-keygen -t ed25519` or
 `ssh-keygen -t rsa -b 4096`.
 
-### Enable root login via SSH
+The keys can then be added to the authentication agent by as described in the
+[corresponding article](#adding-keys-to-authentication-agent)
+
+### Adding Keys to Authentication Agent
+
+The following line will add a key to the authentication agent.
+
+```ssh
+ssh-add id_rsa
+```
+
+Depending on the name of the certificate inside the `~/.ssh` folder the name
+`id_rsa` can vary.
+For example `id_ed25519` is the name if the first generation option was chosen.
+
+### Enable Root Login via SSH
 
 Edit the `/etc/ssh/sshd_config` and change the line containing `PermitRootLogin`
 to `PermitRootLogin yes`.
 
-### Add login via SSH public key
+### Add Login via SSH Public Key
 
 To enable easy login without password you can add the contents of the file
 `~/.ssh/id_rsa.pub` from your local machine to the file `~/.ssh/authorized_keys`
@@ -26,7 +41,7 @@ You can use the modified command below for ease of use:
 cat ~/.ssh/id_rsa.pub | ssh username@server 'cat >> ~/.ssh/authorized_keys'
 ```
 
-### Mount directory with sshfs
+### Mount Directory With SSHFS
 
 To mount a directory (in this case called `directory`) from a remote server
 (in this case called `server` also can be substituted by something like
@@ -35,3 +50,14 @@ To mount a directory (in this case called `directory`) from a remote server
 ```sh
 sshfs server:/directory mountpoint
 ```
+
+### Shorten SSH Connection Commands
+
+By adding the following lines to the file `~/.ssh/config` the command of an SSH
+connection can be shortened from `ssh user@server.tld` to `ssh server`.
+
+```txt
+Host server
+	HostName server.tld
+	User user
+```