u2f seed

Christian Weisgerber
Thu, 02 Jan 2020 23:42:15 -0000

On 2020-01-02, "Fox, Kevin M" <Kevin.Fox at pnnl.gov> wrote:

> In the u2f protocol, my understanding is in the normal case, the web
browser seeds the keypair process with the hostname of the remote server. In the
case of ssh, the hostname is probably not what I would want to do. But the u2f
protocol seems to have a way to handle this.

There is no guarantee that the U2F token derives the key pair in a
deterministic fashion from the challenge/application parameters
passed during registration.

For instance, if I read the firmware code correctly, the Solokey
creates the key material using its built-in random number generator
and only uses its master secret and the application parameter to
wrap the key for the key handle.

--
Christian "naddy" Weisgerber                          naddy at
mips.inka.de