title: git push: permission denied (public key)
body: <p>I'm trying to push a file to a git repo of a friend but errors on public key.</p>
  
  <pre><code>git push origin testbranch
  Permission denied (publickey).
  fatal: Could not read from remote repository.
  </code></pre>
  
  <p>Where and how do we define public / private keys? </p>
  
  <p><code>git remote -v</code> returns:</p>
  
  <pre><code>origin  git@github.com:Sesamzaad/NET.git (fetch)
  origin  git@github.com:Sesamzaad/NET.git (push)
  </code></pre>
  
  <p>Any help is appreciated.</p>