Refactor SSH keys docs

[ci skip]

doc/ssh/README.md

@@ -5,7 +5,7 @@ but you can also share or "push" your changes to other servers.
 Before you can push your changes to a GitLab server
 you need a secure communication channel for sharing information.
 GitLab uses Public-key or asymmetric cryptography
-which "encrypts" a communication channel by locking it with your "private key"
+which encrypts a communication channel by locking it with your "private key"
 and allows trusted parties to unlock it with your "public key".
 If someone does not have your public key they cannot access the unencrypted message.
 
@@ -16,10 +16,13 @@ at the default location by opening a shell, or Command Prompt on Windows,
 and running the following command:
 
 **Windows Command Prompt:**
+
 ```bash
 type %userprofile%\.ssh\id_rsa.pub
 ```
-**GNU/Linux/Mac/PowerShell:**
+
+**GNU/Linux / macOS / PowerShell:**
+
 ```bash
 cat ~/.ssh/id_rsa.pub
 ```
@@ -27,78 +30,82 @@ cat ~/.ssh/id_rsa.pub
 If you see a string starting with `ssh-rsa` you already have an SSH key pair
 and you can skip the next step **Generating a new SSH key pair**
 and continue onto **Copying your public SSH key to the clipboard**.
-If you don't see the string or would like to generate a SSH key pair with a custom name
-continue onto the next step.
+If you don't see the string or would like to generate a SSH key pair with a
+custom name continue onto the next step.
 
 ## Generating a new SSH key pair
 
-To generate a new SSH key, use the following command:
+1. To generate a new SSH key, use the following command:
 
-**GNU/Linux/Mac/PowerShell:**
-```bash
-ssh-keygen -t rsa -C "$your_email"
-```
+    **GNU/Linux / macOS:**
 
-**Windows:**
-On Windows you will need to download
-[PuttyGen](http://www.chiark.greenend.org.uk/~sgtatham/putty/download.html)
-and follow this documentation
-[article](https://the.earth.li/~sgtatham/putty/0.67/htmldoc/Chapter8.html#pubkey-puttygen)
-to generate a SSH key pair.
+    ```bash
+    ssh-keygen -t rsa -C "GitLab" -b 4096
+    ```
 
-### Provide a file path
+    **Windows:**
 
-You will be prompted to input a file path to save your key pair to.
+    On Windows you will need to download
+    [PuttyGen](http://www.chiark.greenend.org.uk/~sgtatham/putty/download.html)
+    and follow this [documentation article][winputty] to generate a SSH key pair.
 
-If you don't already have an SSH key pair use the suggested path by pressing enter.
-Using the suggested path will allow your SSH client
-to automatically use the key pair with no additional configuration.
+1. Next, you will be prompted to input a file path to save your key pair to.
 
-If you already have a key pair with the suggested file path you will need to input a new file path
-and declare what host this key pair will be used for in your `.ssh/config` file,
-see **Working with non-default SSH key pair paths** for more information.
+    If you don't already have an SSH key pair use the suggested path by pressing
+    enter. Using the suggested path will allow your SSH client
+    to automatically use the key pair with no additional configuration.
 
-### Provide a password
+    If you already have a key pair with the suggested file path, you will need
+    to input a new file path and declare what host this key pair will be used
+    for in your `.ssh/config` file, see **Working with non-default SSH key pair paths**
+    for more information.
 
-Once you have input a file path you will be prompted to input a password to secure your SSH key pair.
-Note: It is a best practice to use a password for an SSH key pair,
-but it is not required and you can skip creating a password by pressing enter.
+1. Once you have input a file path you will be prompted to input a password to
+   secure your SSH key pair. It is a best practice to use a password for an SSH
+   key pair, but it is not required and you can skip creating a password by
+   pressing enter.
 
-If you want to change the password of your key, you can use the following command:
-`ssh-keygen -p <keyname>`
+     >**Note:**
+     If you want to change the password of your key, you can use `ssh-keygen -p <keyname>`.
 
-## Copying your public SSH key to the clipboard
+1. The next step is to copy the public key as we will need it afterwards.
 
-To copy your public key to the clipboard, use the appropriate code for you operating system below:
+    To copy your public key to the clipboard, use the appropriate code for your
+    operating system below:
 
-**Windows Command Line:**
-```bash
-type %userprofile%\.ssh\id_rsa.pub | clip
-```
+    **macOS:**
 
-**Windows PowerShell:**
-```bash
-cat ~/.ssh/id_rsa.pub | clip
-```
+    ```bash
+    pbcopy < ~/.ssh/id_rsa.pub
+    ```
 
-**Mac:**
-```bash
-pbcopy < ~/.ssh/id_rsa.pub
-```
+    **GNU/Linux (requires the xclip package):**
 
-**GNU/Linux (requires xclip):**
-```bash
-xclip -sel clip < ~/.ssh/id_rsa.pub
-```
+    ```bash
+    xclip -sel clip < ~/.ssh/id_rsa.pub
+    ```
+
+    **Windows Command Line:**
+
+    ```bash
+    type %userprofile%\.ssh\id_rsa.pub | clip
+    ```
 
-## Adding your public SSH key to GitLab
+    **Windows PowerShell:**
 
-Navigate to the 'SSH Keys' tab in you 'Profile Settings'.
-Paste your key in the 'Key' section and give it a relevant 'Title'.
-Use an identifiable title like 'Work Laptop - Windows 7' or 'Home MacBook Pro 15'.
+    ```bash
+    cat ~/.ssh/id_rsa.pub | clip
+    ```
 
-If you manually copied your public SSH key make sure you copied the entire key
-starting with `ssh-rsa` and ending with your email.
+1. The final step is to add your public SSH key to GitLab.
+
+    Navigate to the 'SSH Keys' tab in you 'Profile Settings'.
+    Paste your key in the 'Key' section and give it a relevant 'Title'.
+    Use an identifiable title like 'Work Laptop - Windows 7' or
+    'Home MacBook Pro 15'.
+
+    If you manually copied your public SSH key make sure you copied the entire
+    key starting with `ssh-rsa` and ending with your email.
 
 ## Working with non-default SSH key pair paths
 
@@ -113,21 +120,17 @@ Below are two example host configurations using their own key:
 # GitLab.com server
 Host gitlab.com
 RSAAuthentication yes
-IdentityFile ~/folder1/private-key-filename
-User mygitlabusername
+IdentityFile ~/.ssh/config/private-key-filename-01
 
 # Private GitLab server
 Host gitlab.company.com
 RSAAuthentication yes
-IdentityFile ~/folder2/private-key-filename
+IdentityFile ~/.ssh/config/private-key-filename
 ```
 
-Note in the gitlab.com example above a username was specified
-to override the default chosen by OpenSSH (your local username).
-This is only required if your local and remote usernames differ.
-
-Due to the wide variety of SSH clients and their very large number of configuration options,
-further explanation of these topics is beyond the scope of this document.
+Due to the wide variety of SSH clients and their very large number of
+configuration options, further explanation of these topics is beyond the scope
+of this document.
 
 Public SSH keys need to be unique, as they will bind to your account.
 Your SSH key is the only identifier you'll have when pushing code via SSH.
@@ -152,13 +155,15 @@ If you want to add the same key to another project, please enable it in the
 list that says 'Deploy keys from projects available to you'. All the deploy
 keys of all the projects you have access to are available. This project
 access can happen through being a direct member of the project, or through
-a group. See `def accessible_deploy_keys` in `app/models/user.rb` for more
-information.
+a group.
 
-Deploy keys can be shared between projects, you just need to add them to each project.
+Deploy keys can be shared between projects, you just need to add them to each
+project.
 
 ## Applications
 
 ### Eclipse
 
 How to add your ssh key to Eclipse: https://wiki.eclipse.org/EGit/User_Guide#Eclipse_SSH_Configuration
+
+[winputty]: https://the.earth.li/~sgtatham/putty/0.67/htmldoc/Chapter8.html#pubkey-puttygen