Setting Up Multiple Git Profiles with SSH and Commit Signing

Many developers work with multiple GitHub accounts—one for personal projects and another for work. Managing multiple accounts with SSH authentication and commit signing can be tricky, but in this guide, I'll walk you through setting up both seamlessly.

for windows use either Git Bash or PowerShell

1. Generate Separate SSH Keys

   We need two separate SSH keys: one for your personal GitHub and another for your work GitHub.

   Run the following commands to generate them:

    ssh-keygen -t ed25519 -C "yourpersonal@email.com" -f ~/.ssh/id_ed25519_personal
    ssh-keygen -t ed25519 -C "yourwork@email.com" -f ~/.ssh/id_ed25519_work
   

   ssh-keygen -t ed25519 -C ‘yourpersonal@email.com’ this part will create ssh key

   -f ~/.ssh/id_ed25519_personal -f stands for file and it will make sure our file is saved with name we provide.

   This will create two key pairs:

   Personal: ~/.ssh/id_ed25519_personal and ~/.ssh/id_ed25519_personal.pub

   Work: ~/.ssh/id_ed25519_work and ~/.ssh/id_ed25519_work.pub

2. Configure SSH for Multiple Accounts

   we’ll configure SSH to use the correct key for each GitHub account. Edit or create your SSH config file:

   For Mac:

    nano ~/.ssh/config
   

   For windows:

    notepad $env:USERPROFILE\.ssh\config
   

   Add the following configuration:

    # Personal GitHub
    Host github-personal
        HostName github.com
        User git
        IdentityFile ~/.ssh/id_ed25519_personal
        IdentitiesOnly yes
   
    # Work GitHub
    Host github-work
        HostName github.com
        User git
        IdentityFile ~/.ssh/id_ed25519_work
        IdentitiesOnly yes
   

   Convert the file to Unix format and set permissions:

   For Mac:

    tr -d '\r' < ~/.ssh/config > ~/.ssh/config_fixed && mv ~/.ssh/config_fixed ~/.ssh/config
    chmod 600 ~/.ssh/config
   

   For Windows:

    (Get-Content $env:USERPROFILE\.ssh\config) -replace "`r", "" | Set-Content $env:USERPROFILE\.ssh\config
    icacls $env:USERPROFILE\.ssh\config /inheritance:r /grant:r "$($env:USERNAME):(R,W)"
   

   Test the SSH Connection

   Run these commands to verify:

    ssh -T git@github-personal
   
    ssh -T git@github-work
   

   If configured correctly, you should see:

    Hi yourusername! You've successfully authenticated...
    Hi yourworkusername! You've successfully authenticated..
   

3. Add SSH Keys to GitHub

   Copy each public key and add it to the respective GitHub account under Settings → SSH and GPG Keys.:

    cat ~/.ssh/id_ed25519_personal.pub
    cat ~/.ssh/id_ed25519_work.pub
   

4. Configure Git to Use Different Profiles

   Set up global config for your personal account:

    git config --global user.name "Your Personal Name"
    git config --global user.email "yourpersonal@email.com"
   

   For work repositories, override this with local config:

    cd ~/work-repo
    git config --local user.name "Your Work Name"
    git config --local user.email "yourwork@email.com"
   

   /work-repo here can be either you git repo or root directory under which you will clone all work repos

5. Set Up Commit Signing for Both Accounts

   GitHub allows you to sign commits using SSH keys. First, configure Git to use SSH signing:

    git config --global gpg.format ssh
   

   Personal Signing Key

    git config --global user.signingkey ~/.ssh/id_ed25519_personal.pub
    git config --global commit.gpgsign true
   

   Work Signing Key (Local Override)

   Inside your work repository:

    git config --local user.signingkey ~/.ssh/id_ed25519_work.pub
    git config --local commit.gpgsign true
   

   Add SSH Signing Key to GitHub

   Go to GitHub → Settings → SSH and GPG Keys → New SSH Key and select Signing Key. Paste your SSH public key (.pub).

6. Configure Allowed Signers for Verification

   Create a file to list trusted signing keys:

   For Mac:

    touch ~/.ssh/allowed_signers
   

   For Windows:

    New-Item -ItemType File -Path $env:USERPROFILE\.ssh\allowed_signers
   

   Edit it (Mac):

    nano ~/.ssh/allowed_signers
   

   Edit it (windows):

    notepad $env:USERPROFILE\.ssh\allowed_signers
   

   Add the following lines:

    <yourpersonalusername> ssh-ed25519 <public key for personal account>
    <yourworkusername> ssh-ed25519 <public key for work account>
   

   Convert the file to Unix format and set permissions:

   For Mac:

    tr -d '\r' < ~/.ssh/allowed_signers > ~/.ssh/allowed_signers_fixed && mv ~/.ssh/allowed_signers_fixed ~/.ssh/allowed_signers
    chmod 600 ~/.ssh/allowed_signers
   

   For Windows:

    (Get-Content $env:USERPROFILE\.ssh\allowed_signers) -replace "`r", "" | Set-Content $env:USERPROFILE\.ssh\allowed_signers
    icacls $env:USERPROFILE\.ssh\allowed_signers /inheritance:r /grant:r "$($env:USERNAME):(R,W)"
   

   Configure Git to use it

   For Mac:

    git config --global gpg.ssh.allowedSignersFile ~/.ssh/allowed_signers
   

   For windows:

    git config --global gpg.ssh.allowedSignersFile $env:USERPROFILE\.ssh\allowed_signers
   

   Setting work repositories:

   For Mac:

    git config --local gpg.ssh.allowedSignersFile ~/.ssh/allowed_signers
   

   For Windows:

    git config --local gpg.ssh.allowedSignersFile $env:USERPROFILE\.ssh\allowed_signers
   

7. Verify Signed Commits

   Make a test commit in one of your repos:

    git commit -S -m "Test signed commit"
   

   verify if it works:

    git log --show-signature
   

   If everything is correct, you should see:

    Good signature from SSH key ID SHA256:xxxxxxxx
   

   And GitHub will show commits as "Verified". ✅