[Swan-dev] Set keyingtries to 1 for Opportunistic Encryption connections

[Andrew Cagney]

Can I attribute these test failures to this discussion?

--- MASTER/testing/pluto/ikev2-59-multiple-acquires-alias/east.console.txt
+++ OUTPUT/testing/pluto/ikev2-59-multiple-acquires-alias/east.console.txt
@@ -33,7 +33,7 @@
 000 "north-eastnets/0x1":   ike_life: 3600s; ipsec_life: 28800s;
replay_window: 32; rekey_margin: 540s; rekey_fuzz: 100%; keyingtries:
0;
 000 "north-eastnets/0x1":   retransmit-interval: 9999ms;
retransmit-timeout: 99s;
 000 "north-eastnets/0x1":   initial-contact:no; cisco-unity:no;
fake-strongswan:no; send-vendorid:no; send-no-esp-tfc:no;
-000 "north-eastnets/0x1":   policy:
RSASIG+ECDSA+ENCRYPT+TUNNEL+PFS+UP+IKEV2_ALLOW+IKE_FRAG_ALLOW+ESN_NO+RSASIG_v1_5;
+000 "north-eastnets/0x1":   policy:
RSASIG+ECDSA+ENCRYPT+TUNNEL+PFS+IKEV2_ALLOW+IKE_FRAG_ALLOW+ESN_NO+RSASIG_v1_5;
 000 "north-eastnets/0x1":   v2-auth-hash-policy: SHA2_256+SHA2_384+SHA2_512;
 000 "north-eastnets/0x1":   conn_prio: 24,24; interface: eth1;
metric: 0; mtu: unset; sa_prio:auto; sa_tfc:none;
 000 "north-eastnets/0x1":   nflog-group: unset; mark: unset;
vti-iface:unset; vti-routing:no; vti-shared:no; nic-offload:auto;

On Sun, 8 Mar 2020 at 22:43, D. Hugh Redelmeier <hugh at mimosa.com> wrote:
>
> | From: Paul Wouters <paul at nohats.ca>
>
> | On Thu, 5 Mar 2020, D. Hugh Redelmeier wrote:
> |
> | > | I meant "resolved by setting it to 1".
> | >
> | > I don't really understand the issues.
> |
> | A failure shunt is installed after the first keyingtries= fails.
> | If a second keyingtries is started, it will want to install the
> | negotiationshunt. What does it mean when these two shunts are
> | different? It is unclear what we _should_ do.
> |
> | The actual bug seems to be that sometimes, the second shunt comes
> | in without widening to the full IP address. I do not yet know how
> | or when this exactly happens. When it does, pluto installs a second
> | shunt because it is different from the first one (eg proto 0 vs proto 6)
> | then later on when a tunnel is installed, only one shunt is removed.
>
> OK.  That is (I think) a separate discussion that we should have.
>
> The code I wrote implemented the same logic as your fix.  So my change
> is neutral with regard to this issue.
>
> | > If the shunts fail, except in special cases, and those cases are
> | > undocumented, we should
> | >
> | > - fix the shunts issue (hard, I assume), or
> |
> | We should either fix the shunt issue, or think of removing shunts
> | completely. While shunts give us a little more fine-grained control
> | on what to do during negotiation, some of that is countered by the
> | XFRM larval state anyway, and additionally, there is a _lot_ of
> | complexity with shunts. That makes it tempting to remove.
>
> I think that this is an important discussion that should be separated
> from this particular bug.
>
> Among other things, shunts were to prevent unexpected leaks in the clear.
> That seems pretty important.  They were also used to mirror kernel state
> in Pluto (it was unreasonable to try to query the kernel whenever Pluto
> needed the information).  Unfortunately, the kernel could change the
> kernel's representation without notifying userland.
>
> It is possible that the design constraints have changed over the last
> decades and a different design might be better.  But just slashing
> without careful analysis seems like a bad idea.  That analysis must
> not be based on a subset of the cases.
>
> Such a change might require sysadmins to change firewalls.  If so, it
> should not just be slipped into a release.
>
> | > Here's an add-on to Paul's code [UNTESTED].
> | >
> | > Since it changes starterwhack, something I'm not an expert in, the code is
> | > particularly suspect.
> |
> | I actually changed it in add_connection() so it is independent on
> | whether the parameters came in via whack or via ipsec.conf.
>
> Right.  That's why I didn't suggest removing your change.
>
> My code intended to implement the same result, but earlier, with a
> more useful diagnostic (I hope -- untested!).
>
> | > It implements that last policy, I hope.
> | > If one were to delete one line, it would only change a defaulted
> | > keyingtries.
> |
> | Which makes this harder to do because we currently merge in our defaults
> | via libipsecconf/whack interactions. By the time add_connection() is
> | called, what was an implicit default is no longer known.
>
> Where I made the change, it is known whether this 0 came from a
> default or an explicit assignment.  The diagnostic is only generated
> if an explicit assignment is being over-ridden.
>
> I fear that your code emits too many diagnostics (i.e. where the 0
> comes from default) and that they are not visible.
>
> That's why I was suggesting my additional change.
>
> Putting a check in the whack code would be good too.  But I don't
> imagine that it is as important.
> _______________________________________________
> Swan-dev mailing list
> Swan-dev at lists.libreswan.org
> https://lists.libreswan.org/mailman/listinfo/swan-dev