(RADIATOR) Possible to Proxy PEAP-EAP-MSCHAP v2 to IAS?

Mike McCauley mikem at open.com.au
Tue Feb 10 04:28:14 CST 2004


Hi Tom,


On Tue, 10 Feb 2004 09:03 pm, Tom Rixom wrote:
> Hello,
>
> It is possible to configure the IAS server into supporting EAP-MSCHAPV2
> as an authentication method. We are still testing the method at this moment
> as this is not documented.
>
> The reason for this is that we are experimenting with the new SecureW2
> Client 2.0 which supports inner EAP. So what you get is TTLS-EAP-MSCHAPV2.

Thats interesting.

>
> It all works quite well but..... (of course their is a but)
>
> One problem is that Radiator sends the user attribute "User-Name:
> Anonymous" in all the inner requests which off course is rejected by the
> IAS. I was already planning on asking Mike for help on this so I might as
> wel do it know.... Mike? ;)

With the EAPAnonymous paramter you can set the User-Name of the inner auth to 
anything you like. It just defaults to anonymous. For example %0 is replaced 
by the EAP identity from the outer auth. Any other special chars can be used 
too.

Cheers.


>
> Regards,
>
> Tom Rixom
> SecureW2
> Alfa & Ariss
>
> > -----Original Message-----
> > From: Jon Snyder [mailto:jon at pdx.edu]
> > Sent: Monday, February 09, 2004 11:24 PM
> > To: 'Mike McCauley'; radiator at open.com.au
> > Subject: RE: (RADIATOR) Possible to Proxy PEAP-EAP-MSCHAP v2 to IAS?
> >
> >
> > Sounds like the same conclusion I came to, so at least we're
> > on the same
> > page.
> >
> > As to some of the other questions on this thread, we haven't done much
> > testing with the Alfa-Ariss client yet, but we find it
> > generally easier and
> > less painful to have people configure something that's
> > already there than
> > add a new piece of software.
> >
> > Anybody have any general pointers on what it would take to
> > turn EAP-MSCHAP
> > into plain RADIUS-MSCHAP?  If I suddenly get some extra time,
> > perhaps I can
> > work on adding that functionality.  That would be the
> > cleanest fit with our
> > model.  Not sure I can convince the Windows guys to let me
> > install Perl and
> > Radiator on their servers :)
> >
> > ----------
> > Jon Snyder
> > Computing and Network Services
> > Portland State University
> > (503) 725-9565
> >
> > -----Original Message-----
> > From: Mike McCauley [mailto:mikem at open.com.au]
> > Sent: Monday, February 09, 2004 2:04 AM
> > To: Jon Snyder; radiator at open.com.au
> > Subject: Re: (RADIATOR) Possible to Proxy PEAP-EAP-MSCHAP v2 to IAS?
> >
> > Hello Jon,
> >
> > On Mon, 9 Feb 2004 07:09 pm, Jon Snyder wrote:
> > > Hi all,
> > >
> > > We're trying to configure EAP for 802.1x wireless
> >
> > authentication with the
> >
> > > general rule that Radiator will authenticate everything it
> >
> > can locally,
> > and
> >
> > > proxy the authentication types it can't.  Our Radiator
> >
> > instance is running
> >
> > > on Solaris with passwords in NIS, so we can't for example
> >
> > authenticate
> >
> > > MS-CHAP v2 requests.
> > >
> > > What I would like to do is proxy PEAP-EAP-MSCHAP v2 (from
> >
> > the Windows XP
> >
> > > SP1 PEAP client) to an IAS server running on Windows 2003, which can
> > > authenticate the MS-CHAP v2 request.  But, if the request
> >
> > is TTLS with PAP
> >
> > > or some other form that can be authenticated locally on the
> >
> > unix host, do
> >
> > > so there.  The problem I think I'm running into is that Radiator is
> > > properly proxying the inner EAP-MSCHAP v2 on to the IAS
> >
> > server, but IAS
> >
> > > can't handle EAP-MSCHAP v2 as it receives it; it wants
> >
> > either PEAP with
> >
> > > MSCHAP v2 inside, or a regular MSCHAP v2 challenge in the
> >
> > radius packet
> > (no
> >
> > > EAP).
> >
> > Its true that IAS cannot handle bare EAP-MSCHAPV2, only when
> > it is tunnelled
> >
> > inside PEAP, so you would have to forward the entire PEAP
> > conversation to
> > the
> > IAS server.
> >
> > The problem is that is is not possible to distinguish between
> > EAP types when
> >
> > trying to figure out where to proxy something. Mainly this is
> > beacause the
> > EAP type is not negotated until several packets have been
> > exchanged, so you
> > have a chicken-egg problem when trying to figure out where to
> > send the
> > requests. The uphot is that you need some other cue when trying to
> > determnine
> > where to send requests. Most commonly this is the realm in
> > the users name,
> > of
> > course.
> >
> > > Is it possible to accomplish what I'm trying to do?  It
> >
> > seems like if I
> >
> > > could "extract" the MSCHAP v2 and send it over to IAS
> >
> > without it being
> >
> > > EAP-MSCHAP v2 it might work.  I know it's possible with
> >
> > TTLS to have one
> >
> > > server take the EAP-TTLS requests, and proxy the actual
> >
> > authentication to
> >
> > > another server that knows nothing about EAP (as demonstrated in the
> >
> > goodies
> >
> > > configs).  Can the same be done with PEAP?
> >
> > I think it might be technically possible for an EAP-MSCHAPV2
> > authenticator
> > to
> > turn the requests into plain RADIUS-MSCHAPV2 and then forward
> > them. However
> > it would require some new code and we dont see muchg demand
> > for this feature
> >
> > (yet).
> >
> > > I have this working if I use an AuthBy FILE for handling the inner
> > > authentication, so I know it's not a general issue with my system or
> > > configuration for PEAP.  But with the AuthBy RADIUS below, no go.
> >
> > This config would prob work if only IAS could understand EAP-MSCHAPV2
> > outside
> > a PEAP tunnel.
> >
> > Actually Radiator understands bare EAP-MSCHAPV2 and when it
> > runs on Windows,
> >
> > it can be configured to authenticate EAP-MSCHAPV2 against AD, LSA etc.
> >
> > MAybe the right answer is to run your Radiator on Windows and
> > configure to
> > auth the inner EAP-MSCHAPV2 with AuthBy LSA?
> >
> > Cheers.
> >
> > > Thanks in advance!
> > >
> > > Here's what I'm doing in the Radiator config (this isn't
> >
> > the whole config,
> >
> > > but should be all the relevant portions):
> > >
> > > <Handler TunnelledByPEAP=1,EAPType=MSCHAP-V2>
> > >         <Log FILE>
> > >                 Filename %L/PEAPInside.log
> > >                 Trace 4
> > >         </Log>
> > >
> > >        <AuthBy RADIUS>
> > >                NoDefault
> > >                EAPType MSCHAP-V2
> > >                <Host win2k3.ias.box>
> > >                        Secret secret
> > >                        AuthPort 1812
> > >                        AcctPort 1813
> > >                </Host>
> > >        </AuthBy>
> > > </Handler>
> > >
> > > <Handler TunnelledByPEAP=1>
> > >         <AuthBy SYSTEM>
> > >                 NoDefault
> > >         </AuthBy>
> > > </Handler>
> > >
> > > <Handler TunnelledByTTLS=1>
> > >         <AuthBy SYSTEM>
> > >                 NoDefault
> > >         </AuthBy>
> > > </Handler>
> > >
> > > <Handler Client-Identifier=wiAPs>
> > >         <Log FILE>
> > >                 Filename %L/PEAPOutside.log
> > >         </Log>
> > >         <AuthBy FILE>
> > >                 Filename %D/users
> > >                 EAPType PEAP,TTLS
> > >
> > >                 EAPTLS_CAFile
> >
> > %D/certificates/thawte/ThawteServerCA.txt
> >
> > >                 EAPTLS_CertificateFile
> > > %D/certificates/radius-server.cert.pem
> > >                 EAPTLS_CertificateType PEM
> > >                 EAPTLS_PrivateKeyFile
> >
> > %D/certificates/radius-server.key.pem
> >
> > >                 EAPTLS_PrivateKeyPassword whatever
> > >                 EAPTLS_MaxFragmentSize 1000
> > >
> > >                 AutoMPPEKeys
> > >         </AuthBy>
> > > </Handler>
> > >
> > > ----------
> > > Jon Snyder
> > > Computing & Network Services
> > > Portland State University
> > >
> > > ===
> > > Archive at http://www.open.com.au/archives/radiator/
> > > Announcements on radiator-announce at open.com.au
> > > To unsubscribe, email 'majordomo at open.com.au' with
> > > 'unsubscribe radiator' in the body of the message.
> >
> > --
> > Mike McCauley                               mikem at open.com.au
> > Open System Consultants Pty. Ltd            Unix, Perl,
> > Motif, C++, WWW
> > 9 Bulbul Place Currumbin Waters QLD 4223 Australia
>
> http://www.open.com.au
> Phone +61 7 5598-7474                       Fax   +61 7 5598-7070
>
> Radiator: the most portable, flexible and configurable RADIUS server
> anywhere. SQL, proxy, DBM, files, LDAP, NIS+, password, NT, Emerald,
> Platypus, Freeside, TACACS+, PAM, external, Active Directory, EAP, TLS,
> TTLS, PEAP etc on Unix, Windows, MacOS etc.
>
>
> ===
> Archive at http://www.open.com.au/archives/radiator/
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-- 
Mike McCauley                               mikem at open.com.au
Open System Consultants Pty. Ltd            Unix, Perl, Motif, C++, WWW
9 Bulbul Place Currumbin Waters QLD 4223 Australia   http://www.open.com.au
Phone +61 7 5598-7474                       Fax   +61 7 5598-7070

Radiator: the most portable, flexible and configurable RADIUS server 
anywhere. SQL, proxy, DBM, files, LDAP, NIS+, password, NT, Emerald, 
Platypus, Freeside, TACACS+, PAM, external, Active Directory, EAP, TLS, 
TTLS, PEAP etc on Unix, Windows, MacOS etc.

===
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