ssh: improved structure and linking

wiki/linux/git_(package).md

@@ -48,12 +48,13 @@ git ls-files -v | grep "^S"
 Authentication by default is done via a username and a password.
 For some services such as GitHub.
 it is not possible to use password as an authentication method.
-The other possibility to authenticate to git is by using
+The other possibility to authenticate to git is by using [SSH](/wiki/ssh.md).
-[SSH](/wiki/linux/ssh.md).
 
+The following sections assumes using a [Linux-based system](/wiki/linux.md) using
+[OpenSSH](/wiki/linux/openssh.md).
 For this a
-[SSH certificate has to be created](/wiki/linux/ssh.md#generate-new-keys) and
+[SSH certificate has to be created](/wiki/linux/openssh.md#generate-new-keys) and
-[added to the authentication agent](/wiki/linux/ssh.md#adding-keys-to-authentication-agent).
+[added to the authentication agent](/wiki/linux/openssh.md#adding-keys-to-authentication-agent).
 Afterwards it the public SSH key to be added to the git server.
 For GitHub there is
 [a guide on that topic](https://docs.github.com/en/get-started/getting-started-with-git/why-is-git-always-asking-for-my-password).
@@ -71,7 +72,7 @@ git clone https://github.com/tiyn/wiki
 By using the SSH config file the clone command can be shortened to
 `git clone github:tiyn/wiki`.
 For this follow the
-[corresponding section in the SSH entry](/wiki/linux/ssh.md#shorten-ssh-connection-commands).
+[corresponding section in the SSH entry](/wiki/linux/openssh.md#shorten-ssh-connection-commands).
 Set `Host` to `github`, `HostName` to `github.com` and `User` to `git`.
 
 ### Improved `git diff`

wiki/linux/openssh.md

@@ -1,10 +1,11 @@
-# SSH
+# OpenSSH
 
-SSH is a network protocoll to securely connect to a computer.
+[OpenSSH](https://www.openssh.com) is an implementation of the [SSH protocol](/wiki/ssh.md).
-In this article it is assumed that `openssh` is used.
 
 ## Usage
 
+This section addresses the usage of OpenSSH.
+
 ### Generate New Keys
 
 To generate new ssh keys simply run `ssh-keygen -t ed25519` or
@@ -35,15 +36,30 @@ to `PermitRootLogin yes`.
 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`
 on the machine you want to log into.
-You can use the modified command below for ease of use:
+
+There are two options to add the public key to the remote machine.
+The first is a more manual approach.
+`<path-to-public-key>` is the path to the public key (for example `~/.ssh/id_rsa.pub`) and `<host>`
+is the (user and) server to add the key to (for example `user@192.168.178.16`).
 
 ```sh
-cat ~/.ssh/id_rsa.pub | ssh username@server 'cat >> ~/.ssh/authorized_keys'
+cat <path-to-public-key> | ssh <host> 'cat >> ~/.ssh/authorized_keys'
 ```
 
 This can also be more or less fully automated using the `-G` flag of SSH as described in 
 [a YouTube video by nixhero](https://www.youtube.com/watch?v=xCX14u9XzE8).
 
+The second option is a bit safer, due to using OpenSSHs tools, was described in a
+[StackOverflow comment by Boy](https://stackoverflow.com/questions/18690691/how-to-add-a-ssh-key-to-remote-server).
+It functions similar to the first and uses the following command.
+
+```sh 
+ssh-copy-id -f -i <path-to-public-key> <host>
+```
+
+The `-f` flag can alos be omittet to check if the key is already installed.
+For being very safe is important, a dry run can be performed using the `-n` flag.
+
 ### Mount Directory With SSHFS
 
 This section is loosely based on

wiki/ssh.md

@@ -0,0 +1,10 @@
+# SSH
+
+SSH is a network protocoll to securely connect to a computer.
+
+## Implementations
+
+There are various implementations of the SSH protocol.
+
+- [OpenSSH](/wiki/linux/openssh.md) is an SSH implementation for
+  [Linux-based systems](/wiki/linux.md).