For a secure connection to push git commits, the Xfce project uses SSH keys to authorize on the server. This has the advantage a secure connection is established between the server with simple passwords.
SSH keys are stored in your home directory in the ~/.ssh directory. To generate a key pair use the following command:
cd ~/.ssh .ssh ssh-keygen -t dsa -f id_dsa Generating public/private dsa key pair. Enter passphrase (empty for no passphrase): [ENTER] Enter same passphrase again: [ENTER] Your identification has been saved in id_dsa. Your public key has been saved in id_dsa.pub. The key fingerprint is: e7:c3:bd:c9:33:2e:19:33:b2:62:75:74:b3:99:b1:99 user@localhost
After you have created the key files, you should submit the id_dsa.pub file to us in the text field. This string looks like ssh-dss ... user@localhost.
You can read about this in the Xfce Wiki.