Hi，all In section 9.1 ， “One attractive implementation strategy for channel binding is to add channel binding support to a tunnel method which can tunnel an inner EAP authentication.”was expected to introducing implementing channel binding on tunnel, but was sudden to turn to cryptographic binding by "" Tunnel methods sometimes use cryptographic binding," and began on weakness of tunnel method with cryptographic binding, especially on a specific (or typical) implementation with MSK.
In my opinion, these are two different topic, better in separate paragraghs; and the first topic needs some explanation, pros and cons, why not adopt that implementation since it is attractive. Also, on tunnel method with channel binding, I think there is some point unclear. According to section 4.2 "The channel bindings MUST be transported with integrity protection based on a key known only to the peer and EAP server. " section 6 "The channel binding protocol defined in this document must be transported after keying material has been derived between the EAP peer and server, and before the peer would suffer adverse affects from joining an adversarial network." To my understanding, channel binding exchange happens after a MSK is derived between EAP peer and EAP server, and before MSK is transported to authenticator. If not, for example, after MSK is transported to authenticator, of course authenticator can control the channel binding exchange. I think that is why the EAP cryptograhic binding draft was put forward. If it is made clear and MUST that " MSK transportation to authenticator" happens after channel binding exchange finishes, I don't think an extra crypto binding is necessary. and to make it clear， I suggest EAP server transport MSK after it has obtained explicit response from EAP peer to authorize the action. Regards~~~ -Sophia, Sujing Zhou Joe Salowey <jsalo...@cisco.com> 发件人: emu-boun...@ietf.org 2012-05-15 22:59 收件人 emu@ietf.org 抄送 Sam Hartman <hartmans-i...@mit.edu> 主题 Re: [Emu] I-D Action: draft-ietf-emu-chbind-15.txt Please respond on the list by May 25, 2012. Thanks, Joe On May 14, 2012, at 12:10 PM, Sam Hartman wrote: > > > This version includes a large number of changes mostly to respond to the > secdir review. > > I'm not entirely sure that Stephen Hanna will be happy with the changes > in section 9, but I'd like to start there and see where we are. I think > it's a good idea for WG members to review these changes. > _______________________________________________ > Emu mailing list > Emu@ietf.org > https://www.ietf.org/mailman/listinfo/emu _______________________________________________ Emu mailing list Emu@ietf.org https://www.ietf.org/mailman/listinfo/emu
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