apache/ant-ivy — pull request #3 by cstanfill (2014-11-28 07:08:45+00:00)
Title: Lets ssh-based resolvers use an ~/.ssh/config file to find username/hostname/keyfile options

I haven't tested it for sftp, but it should theoretically work just as well as it does for the ssh resolver. Plays nice with the ssh-agent feature from Jsch, too.