curl-w32/docs/cmdline-opts/negotiate.md

c	SPDX-License-Identifier	Long	Help	Protocols	Category	Added	Multi	See-also	Example
Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.	curl	negotiate	Use HTTP Negotiate (SPNEGO) authentication	HTTP	auth http	7.10.6	mutex	basic ntlm anyauth proxy-negotiate	--negotiate -u $URL

--negotiate

Enables 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 user name and password from the --user option are not actually used.