eap Mailing List: Re: channel binding consensus call

[Jari Arkko (jari.arkko]

Salowey, Joe wrote:

> I think
> there are three different approaches that have been discussed as
> "channel bindings"
>
> 1. both parties pass data into the EAP method.  The data is bound to the
> authentication exchange so it can't be modified.  If the data input by
> both parties matches then the method succeeds, else the method fails.
> This approach is similar to "channel bindings" used in the GSS-API.
>
> 2. Both parties pass data into the method that is bound to the
> authentication exchange so it can't be modified and can be output on the
> other side.  Each party takes the exported data from the method and
> validates it to determine if there is success or failure. 
>
> 3. Both parties input data independent of EAP that gets mixed into the
> key material that is output from EAP.  If the data matches the keys
> match, if the keys don't match then keys don't match. 
>
> Type 1 and 2 require support from EAP methods.  Type 1 and 3 fail if
> there is any mismatch in data where type 2 allows for some flexibility.
> Type 3 requires that you use go through the process of using the derived
> key material before you discover a problem, whereas type 1 fails in the
> method.  Type 3 probably requires the most AAA work, although they
> probably could all benefit from it. 
>  
This is a good classification, thanks!

--Jari