the_information_nexus/tech_docs/ssh-agent.md

ssh-keygen -t ed25519 -C "newton214@gmail.com"

Press Enter to accept the default file location

Enter and confirm a passphrase (recommended)

eval "$(ssh-agent -s)" ssh-add ~/.ssh/id_ed25519 pbcopy < ~/.ssh/id_ed25519.pub

Now paste the copied public key into the relevant service

---

Certainly! Here’s a detailed explanation of each step and how to use them:

eval "$(ssh-agent -s)"

What it Does:

• This command starts the SSH agent in the background. The SSH agent is a program that keeps track of your SSH keys and passphrases, making it easier to use SSH keys without entering the passphrase every time you connect to a server.

How to Use It:

• Open your Terminal.
• Run the command:

  eval "$(ssh-agent -s)"
  

• This will start the SSH agent and output a process ID indicating that the agent is running.

ssh-add ~/.ssh/id_ed25519

What it Does:

• This command adds your SSH private key to the SSH agent. The SSH agent can then use this key for authentication without requiring you to enter the passphrase every time.

How to Use It:

• After starting the SSH agent, run the following command:

  ssh-add ~/.ssh/id_ed25519
  

• If you created your SSH key with a different name or location, adjust the path accordingly.
• You will be prompted to enter the passphrase for the key if you set one during the key generation.

pbcopy < ~/.ssh/id_ed25519.pub

What it Does:

• This command copies the contents of your public key file to the clipboard. pbcopy is a macOS command that places the output of a command into the system clipboard.

How to Use It:

• Run the command:

  pbcopy < ~/.ssh/id_ed25519.pub
  

• After running this command, the contents of your id_ed25519.pub file (your public key) will be in your clipboard, ready to be pasted.

Adding the Public Key to a Service

Where and How to Use It:

• GitHub:

  • Go to GitHub SSH settings.
  • Click "New SSH key".
  • Give your key a title (e.g., "My MacBook Pro").
  • Paste the public key from your clipboard into the "Key" field.
  • Click "Add SSH key".

• GitLab:

  • Go to GitLab SSH settings.
  • Paste the public key from your clipboard into the "Key" field.
  • Give your key a title.
  • Click "Add key".

• Remote Servers:

  • SSH into your remote server.
  • Open or create the ~/.ssh/authorized_keys file:

    nano ~/.ssh/authorized_keys
    

  • Paste the public key into this file.
  • Save and close the file.

By following these steps, you enable secure, password-less authentication to your remote services and servers using your SSH key. Here’s a summary of the complete process:

1. Generate SSH Key:

   ssh-keygen -t ed25519 -C "your_email@example.com"
   

2. Start SSH Agent:

   eval "$(ssh-agent -s)"
   

3. Add SSH Key to Agent:

   ssh-add ~/.ssh/id_ed25519
   

4. Copy Public Key to Clipboard:

   pbcopy < ~/.ssh/id_ed25519.pub
   

5. Add Public Key to Service:

   • For GitHub, GitLab, or other services, follow the instructions specific to the platform to paste and save your public key.

This setup ensures that you can connect to your services and servers securely without repeatedly entering your passphrase.