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Re: phase 2 and ports
In message <200006240131.e5O1VJJ109685@thunk.east.sun.com>, Bill Sommerfeld wri
tes:
>
>Multiple SA's isn't necessarily a problem -- from a crypto-paranoia
>standpoint, it's better to use different keys for different things.
Usually, that's correct, though from a traffic analysis standpoint it's
not. Also see my paper on probable plaintext attacks on IPsec.
>
>
> > b) an application-ID would be usefull for applications that do NOT know a
> > priori what ports to use (l2tp for example). I could see using the tuple
> > protocol:port as an application identifier, and somehow 'teach' ipsec to
> > identify what traffic constitutes that application.
>
>warning: This opens a naming can-of-worms.
>
>With some application assistance (i.e., ftpd telling the stack "I want
>the data connection I'm initiating to connect back to the same
>principal/entity which initiated the control connection i accepted")
>this might not be so bad.
>
>I'm increasingly coming to think that we need to start specifying the
>handling of principals and identities within IPSEC and IKE a bit more
>closely. for what it's worth, I like the general properties of the
>model presented in [1] quite a bit, but fitting that into the existing
>IKE framework will be messy.
"Opens" the can of worms? I wish we would open it -- I've been
complaining about this issue for years. (See
http://www.research.att.com/~smb/talks/ipsec-cert.ps, which is a talk I
gave in December, 1996 at the San Jose IETF.)
--Steve Bellovin