git@github.com: Permission denied (Linux Guide)

GitHub SSH Authentication and Email Privacy Guide (git@github.com: Permission denied)

If you ever encounter the error below, be sure to check this guide:

git@github.com: Permission denied (publickey).
fatal: Could not read from remote repository.

Please make sure you have the correct access rights and the repository exists.

Prerequisites

• Git installed
• GitHub account
• Linux/Unix terminal (bash)

1. Check for Existing SSH Keys

First, check if you already have SSH keys:

ls -al ~/.ssh

Look for files like:

• id_rsa (private key)
• id_rsa.pub (public key)

2. Generate a New SSH Key

If you want to delete the existing keys (id_rsa, id_rsa.pub) and start over, follow these steps:

# Remove private key
rm ~/.ssh/id_rsa

# Remove public key
rm ~/.ssh/id_rsa.pub

Or remove multiple key pairs (if you have)

# Remove all RSA keys
rm ~/.ssh/id_rsa*

If no existing keys are found, generate a new SSH key:

ssh-keygen -t rsa -b 4096 -C "your_email@example.com"

Key Generation Steps:

1. When prompted for file location, press Enter to accept default
2. Optional: Set a passphrase for additional security
3. The system will generate two files:
   • Private key (id_rsa)
   • Public key (id_rsa.pub)

4. You can always check it from here:
   

   ls -al ~/.ssh
   

3. Email Privacy Configuration

GitHub Email Privacy

GitHub provides several options to protect your email privacy:

1. Public Email Address

   • Visible to everyone on GitHub
   • Used in commit metadata

2. Private Email Address

   • Provided by GitHub
   • Keeps your personal email hidden
   • Format: username@users.noreply.github.com

Configuring Email Privacy

Step 1: GitHub Account Settings

1. Navigate to GitHub Email Settings
2. Choose your preferred privacy option:
   • Keep email address private
   • Use GitHub-provided private email

Step 2: Configure Local Git Email

Use the GitHub-provided private email for commits:

# Set global Git email (replace with your GitHub username)
git config --global user.email "username@users.noreply.github.com"

# Optionally set your name
git config --global user.name "Your Name"

Verification

• Check current Git configuration:

  git config --global user.email
  git config --global user.name

4. Display Your Public SSH Key

cat ~/.ssh/id_rsa.pub

Copy the entire output - this is the key you'll add to GitHub.

5. Add SSH Key to GitHub

Web Interface Steps:

1. Log into GitHub.com
2. Click on your profile picture → Settings
3. Navigate to "SSH and GPG keys"
4. Click "New SSH key"
5. Give the key a descriptive title (e.g., "MyThinkPad")
6. Paste the copied public key

6. Configure SSH Agent

Start the SSH agent and add your key:

# Start the SSH agent
eval "$(ssh-agent -s)"

# Add your SSH private key
ssh-add ~/.ssh/id_rsa

7. Test GitHub Connection

Verify your SSH connection:

ssh -T git@github.com

Expected output includes a success message with your GitHub username like this:

"Hi <username>! You've successfully authenticated, but GitHub does not provide shell access."

Troubleshooting Common Issues

Permission Denied Errors

• Ensure key permissions are correct:

  chmod 600 ~/.ssh/id_rsa
  chmod 644 ~/.ssh/id_rsa.pub

Multiple GitHub Accounts

• Use different keys for different accounts
• Configure ~/.ssh/config to specify keys

Best Practices

• Use a strong passphrase
• Regularly rotate SSH keys
• Remove keys from GitHub when no longer in use
• Protect your email privacy
• Use GitHub-provided private email for commits

Verification Checklist

• SSH key generated
• Key added to GitHub
• SSH agent configured
• Email privacy configured
• Successful GitHub connection test

Additional Resources

• GitHub SSH Documentation
• GitHub Email Privacy Settings