Re: The remaining IKEv2 issues

[Michael Richardson <mcr@sandelman.ottawa.on.ca>]

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>>>>> "Theodore" == Theodore Ts'o <tytso@mit.edu> writes:
    Theodore> The final issue #65, concerns whether or not non key-generating
    Theodore> EAP methods should be supported, in order to avoid a
    Theodore> Man-in-the-middle attack (MITM) attack.  However, as Charlie
    Theodore> has pointed out, as used in IKEv2, the server is authenticated
    Theodore> with a certificate before the authentication code is passed.

  My understanding of the MITM attack on non key-generating EAP methods is
that nothing we do in IKEv2 prevents this. This is because the attack is
not between two IPsec devices, but between different kinds of devices.

  I.e. you do key-less EAP with a web server as part of HTTPS, and the
*web server* then does key-less EAP IKE2, acting a kind of nefarious
algorithm proxy.

  We demand that each end know the generated EAP key so that we can bind the
key to the authenticator used. The above web server wouldn't know the
generated key, so the attack is defeated.

    Theodore> In addition, given the requirement to support one-time password
    Theodore> and Generic Token cards, we can not forbid the use of non-kg
    Theodore> EAP schemes.  Hence, given that the MITM attack which was the
    Theodore> concern raised by issue #65 is not an issue for IKEv2, we
    Theodore> believe that this is not something that should hold back the
    Theodore> publication of IKEv2 as a Proposed Standard.

  So, the only way to support these kind of things is by using EAP?
  I'm not complaining, I'm just asking for confirmation.

    Theodore> closed (or as closed as they are going to be), we believe that
    Theodore> the -10 version is ready for IETF last call, once it the -10
    Theodore> version has been processed by the IETF secretariat.

  wow.

]      Out and about in Ottawa.    hmmm... beer.                |  firewalls  [
]   Michael Richardson, Sandelman Software Works, Ottawa, ON    |net architect[
] mcr@sandelman.ottawa.on.ca http://www.sandelman.ottawa.on.ca/ |device driver[
] panic("Just another Debian/notebook using, kernel hacking, security guy");  [


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