How to generate a SSH key in Windows 10

What is a SSH Key?

SSH stands for Secure Shell and is a method used to establish a secure connection between two computers.  SSH works by authenticating based on a key pair, with a private key being on a remote server and the corresponding public key on a local machine. When the keys match, access is granted to the remote user. 

SSH keys are used for authentication and by setting an SSH key on your gitlab and/or github profile, you can connect using git without using an username and password each time; however, if you set a passphrase on your SSH key, you will need to use the passphrase to use the key. 

In this how-to article,  I will show how to generate a SSH key on Windows 10.  I have spit Step 1 down into two sections: The PowerShell way, and the Windows App & Features way.

STEP 1: Install the Windows 10 OpenSSH Client using PowerShell

1. Run the following command:
   Get-WindowsCapability -Online | ? Name -like ‘OpenSSH*’
   in an elevated PowerShell to verify if the OpenSSH Client is installed. (Figure 1)
   
2. If the OpenSSH Client isn’t installed, run the following command:
   Add-WindowsCapability -Online -Name OpenSSH.client~~~~0.0.1.0
   from the elevated PowerShell.

STEP 1: Install the Windows 10 OpenSSH Client using “Apps & Features“

1. Open the Settings panel, then click Apps or Search for “Apps & Features“

2. Click on “Optional Features“

3. Click on “Add a Feature“

4. Scroll down until you find “OpenSSH Client“

5. Select the “OpenSSH Client” and click the “Install (1)” button

6. Windows 10 will install the OpenSSH Client.

STEP 2: Open an elevated Command Prompt

1. Press the Windows key

2. type cmd.

3. Under Best Match, right-click Command Prompt.

4. Click Run as Administrator.

STEP 3: Use OpenSSH to Generate an SSH Key Pair

1. In the command prompt, type the following: ssh-keygen -t rsa -b 4096-C "<YOUR EMAIL ADDRESS>"

Notes

1. US National Institute of Standards and Technology recommends that you use a key size of at least 2048 bits.  
2. If you have a key saved in the default location in STEP 3, it may over write an existing key and cause issues with services that depend on that key.
3. Using a passphrase on your ssh keys are highly recommended.