[strongSwan] Strongswan client support for the XAUTH_PASSCODE attribute

[MN Lists]

Hi,

This is my first message to the list so sorry in advance if the answer is obvious or well-known.
Also, sorry if my terminology is messed up, hopefully you will understand my issue.

I have a Juniper ScreenOS gateway that does IKEv1 VPNs with RSA and then XAuth authentication
towards an RSA SecurID box. SecurID is an MFA implementation with hardware tokens that display
a new 6-digit number every 60 seconds.

Clients can connect to it from Mac OS X with a client called NCP Secure Entry and from Windows
with the Shrewsoft client. In the past vpnc on Linux was working but as it has not been developed
since a long time and doesn't support newer algorithms, I'm looking for an alternative and
Strongswan looks promising.

So far I have been able to get IKE phase1 up but it fails on XAuth. It looks as if the gateway
is sending a request for X_USER and X_CODE but charon is responding with just X_USER. Here is
a log excerpt:

apr 01 17:48:08 phoenix charon-debug[21177]: 02[IKE] authentication of 'gw.example.com' with RSA_EMSA_PKCS1_NULL successful
apr 01 17:48:08 phoenix charon-debug[21177]: 02[IKE] activating new tasks
apr 01 17:48:08 phoenix charon-debug[21177]: 02[IKE] nothing to initiate
apr 01 17:48:11 phoenix charon-debug[21177]: 07[NET] received packet: from 212.112.174.86[4500] to 172.20.33.34[4500] (92 bytes)
apr 01 17:48:11 phoenix charon-debug[21177]: 07[IKE] next IV for MID 3123281050 => 16 bytes @ 0x7f0304001ed0
apr 01 17:48:11 phoenix charon-debug[21177]: 07[IKE]    0: 51 2C 54 DC D7 31 2D 5F 5D 84 00 10 81 42 88 2B  Q,T..1-_]....B.+
apr 01 17:48:11 phoenix charon-debug[21177]: 07[ENC] parsed TRANSACTION request 3123281050 [ HASH CPRQ(X_TYPE X_USER X_CODE) ]
apr 01 17:48:11 phoenix charon-debug[21177]: 07[IKE] Hash => 32 bytes @ 0x7f03040026b0
apr 01 17:48:11 phoenix charon-debug[21177]: 07[IKE]    0: 87 1C CA 53 F3 1A 81 40 E3 68 E8 78 EA 1C CF CE  ...S... at .h.x....
apr 01 17:48:11 phoenix charon-debug[21177]: 07[IKE]   16: B3 53 17 C6 8C 1B E7 F3 CA DD 50 DC F7 60 97 DD  .S........P..`..
apr 01 17:48:11 phoenix charon-debug[21177]: 07[IKE] next IV for MID 3123281050 => 16 bytes @ 0x7f02f8005600
apr 01 17:48:11 phoenix charon-debug[21177]: 07[IKE]    0: 33 C2 3E 9C 64 14 4C 87 85 C2 1B 26 45 84 2D FF  3.>.d.L....&E.-.
apr 01 17:48:11 phoenix charon-debug[21177]: 07[IKE] Hash => 32 bytes @ 0x7f0304001ed0
apr 01 17:48:11 phoenix charon-debug[21177]: 07[IKE]    0: CB A7 62 8F 3F E0 98 7B 92 75 7F AE 70 B6 E4 0C  ..b.?..{.u..p...
apr 01 17:48:11 phoenix charon-debug[21177]: 07[IKE]   16: 9E B8 66 14 91 79 63 45 5C 9E B1 EF FD B3 5F B9  ..f..ycE\....._.
apr 01 17:48:11 phoenix charon-debug[21177]: 07[ENC] generating TRANSACTION response 3123281050 [ HASH CPRP(X_USER) ]

Relevant swanctl authentication and secret sections are:

connections {
    conn1 {
        local-2 {
            auth = xauth-generic
            xauth_id = xauthuser
        }
    }
}

secrets {
        xauth-1 {
                id-1 = xauthuser
                secret = 1234556677
        }

Is this a well known deficiency in strongswan or is there some configuration that can make
this work?

I'm happy to supply any further information that could help resolve this.

Many thanks,
/Mikael

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