82.3 SSH Public Keys Management

20210913

It is good practice to utilise multiple public keys for different scenarios. For example, generate a public key for accessing a GitHub repository from multiple servers. Copy the private key to each server that requires access to the GitHub repository. Ensure the private key is passphrase protected, noting that the sysadmins (or anyone with sudo access) on those servers could otherwise compromise your GitHub access.

$ ssh-keygen -f ~/.ssh/id_rsa_github

Generating public/private rsa key pair.
Enter passphrase (empty for no passphrase): 
Enter same passphrase again: 
Your identification has been saved in /home/kayon/.ssh/id_rsa_github
Your public key has been saved in /home/kayon/.ssh/id_rsa_github.pub
The key fingerprint is:
SHA256:RwrmBN3Tzh+Zdfkj8jJdhHFFuUhjny73jdJjI7/V7T8 kayon@alpine
The key's randomart image is:
+---[RSA 3072]----+
|        +     .o+|
|       o B   . =o|
|      o * o . o.o|
|      .o + . . o.|
|     . S . o. o o|
|         . . * +o|
|          o +.*.o|
|         . + ==F.|
|          o.*=C*B|
+----[SHA256]-----+

Install the contents of /home/kayon/.ssh/id_rsa_github.pub on GitHub. Add the private key to your local ssh-agent:

$ ssh-add ${HOME}/.ssh/id_rsa_github

Enter passphrase for /home/kayon/.ssh/id_rsa_github: 
Identity added: /home/kayon/.ssh/id_rsa_github (kayon@alpine)

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