+Currently (2008-08-23), gnutls does not support this operation. In order
+to take this step, you will need to upgrade to a patched version of
+gnutls. You can easily upgrade a Debian system by adding the following
+to /etc/apt/sources.list.d/monkeysphere.list:
+
+ deb http://monkeysphere.info/debian experimental gnutls
+ deb-src http://monkeysphere.info/debian experimental gnutls
+
+Next, run `aptitude update; aptitude install libgnuttls26`.
+
+With the patched gnutls installed, you can feed your authentication sub
+key to your ssh agent by running: