--negotiate

Enable Negotiate (SPNEGO) authentication.

This option requires a library built with GSS-API or SSPI support. Use --version to see if your curl supports GSS-API/SSPI or SPNEGO.

When using this option, you must also provide a fake --user option to activate the authentication code properly. Sending a '-u :' is enough as the username and password from the --user option are not actually used.