Artifactory also supports accessing private VCS repositories such as a private GitHub or any self-hosted authenticated one.
To do so, simply add your credentials under Advanced Settings of the remote repository configuration panel.
Credentials when redirected
Some git providers (GitHub included) redirects download requests to a CDN provider.
You will need your credentials to pass along with the redirected request, simply check the Lenient Host Authentication and the credentials will pass transparently on each redirected request.