Vijay Devarapalli writes:
> Agree. Here is the text proposal to address this issue.
> 
>     If the gateway decides to redirect the client during the IKE_AUTH
>     exchange, based on the identity presented by the client in the
>     IKE_AUTH request message, it prevents the creation of a CHILD SA and
>     sends the REDIRECT payload in the IKE_AUTH response.  When the client
>     receives the IKE_AUTH response with the REDIRECT payload, it MUST
>     send an empty message as an acknowledgement and delete the IKEv2 SA
>     as described above.

That empty message as an acknowledgement is completely against the
generic IKEv2 exchange model. That is unacceptable.

Also the text does not say whether the IKE SA creation succeded or
failed when REDIRECT was sent. As REDIRECT is status notification it
would indicate that IKE SA succeded, and in your example it must have
succeeded, as initiator used it after the IKE_AUTH to send that empty
message.

I think the correct way to do that is to split REDIRECT to two
different notifications, one REDIRECT that is allocated from the
NOTIFY MESSAGES - ERROR TYPES range (0-8191) which indicates that the
IKE SA creation failed and initiator MUST move to new location. This
is the one that should be used in the IKE_SA_INIT and IKE_AUTH phase.
Then there would be another status REDIRECT, which is allocated from
the NOTIFY MESSAGES - STATUS TYPES. This status REDIRECT would be used
in the INFORMATIONAL exchanges, i.e. where it does not cause IKE SA to
be deleted when such notify message is received.

This whole discussion is putting more and more me back to my original
opinion that we should NOT allow redirects during IKE_AUTH.

There is reason to do the redirect during IKE_SA_INIT before doing
Diffie-Hellman.

There is reason to do it after kwowing the identity, but as others has
pointed out in that case it should be done only after the identity has
been proven. If redirection is done only after identity has been
proven, then it can be done as separate INFORMATIONAL exchange after
the IKE_AUTH.

I do not want REDIRECT to be defined so that it can be sent any time
during IKE_AUTH as that exponentially multiple the number of test
cases required for IKE_AUTH tests (i.e. test REDIRECT during all the
possible half a dozen messages using different authentication methods
including multiple authentication etc). 
-- 
[email protected]
_______________________________________________
IPsec mailing list
[email protected]
https://www.ietf.org/mailman/listinfo/ipsec

Reply via email to