Running or undoing start actions might require enumerating IKE_SAs,
which in turn might have to enumerate peer configs concurrently, which
requires acquiring a read lock. So if we keep holding the write lock while
enumerating the SAs we provoke a deadlock.
By preventing other threads from acquiring the write lock while handling
actions, and thus preventing the modification of the configs, we largely
maintain the current synchronous behavior. This way we also don't need to
acquire additional refs for config objects as they won't get modified/removed.
Fixes#1185.
This allows e.g. modified versions of xl2tpd to set the mark in
situations where two clients are using the same source port behind the
same NAT, which CONNMARK can't restore properly as only one conntrack entry
will exist with the mark set to that of the client that sent the last packet.
Fixes#1230.
By settings a matchmask that covers the complete rule we ensure that the
correct rule is deleted (i.e. matches and targets with potentially different
marks are also compared).
Since data after the passed pointer is actually dereferenced when
comparing we definitely have to pass an array that is at least as long as
the ipt_entry.
Fixes#1229.
This adds the p-cscf plugin that can request P-CSCF server addresses from
an ePDG via IKEv2 (RFC 7651). Addresses of the same families as requested
virtual IPs are requested if enabled in strongswan.conf for a particular
connection. The plugin currently writes received addresses to the log.
With these changes initiators of make-before-break reauthentications
suspend online revocation checks until after the new IKE_SA and all
CHILD_SAs are established. See f1cbacc5d1 for details why that's
necessary.
We do these checks after the SA is fully established.
When establishing an SA the responder is always able to install the
CHILD_SA created with the IKE_SA before the initiator can do so.
During make-before-break reauthentication this could cause traffic sent
by the responder to get dropped if the installation of the SA on the
initiator is delayed e.g. by OCSP/CRL checks.
In particular, if the OCSP/CRL URIs are reachable via IPsec tunnel (e.g.
with rightsubnet=0.0.0.0/0) the initiator is unable to reach them during
make-before-break reauthentication as it wouldn't be able to decrypt the
response that the responder sends using the new CHILD_SA.
By delaying the revocation checks until the make-before-break
reauthentication is completed we avoid the problems described above.
Since this only affects reauthentication, not the original IKE_SA, and the
delay until the checks are performed is usually not that long this
doesn't impose much of a reduction in the overall security.
On failure the SA is deleted and reestablished as configured. The task
is activated after the REAUTH_COMPLETE task so a make-before-break reauth
is completed before the new SA might get torn down.
We already do this in the trusted public key enumerator (which
internally uses the trusted certificate enumerator) but should do so
also when this enumerator is used directly (since the public key
enumerator has the read lock the additional call will just be skipped
there).
Our default config files are very charon specific. So to avoid
confusion when only charon-systemd is installed we just default to all
settings defined for charon. Since charon-systemd probably won't be used
together with charon this should not cause conflicts (settings may still
be overridden via the charon-systemd section).
Because settings are already accessed in library_init(), calling
add_fallback() externally after calling library_init() is not ideal.
This way namespaces already serve as fallback while library_init() is
executed and they are also in the correct order so that libstrongswan is
always the last root section.
This also restores the charon.signature_authentication_constraints
functionality, that is, if no explicit IKE signature schemes are
configured we apply all regular signature constraints as IKE constraints.
This adds support for IKEv2 redirection (RFC 5685). There is currently
no default implementation of the redirect_provider_t interface provided.
Plugins may implement the interface to decide if and when to redirect
connecting clients. It is also possible to redirect established IKE_SAs
via VICI/swanctl.
An attacker could blindly send a message with invalid nonce data (or none
at all) to DoS an initiator if we just destroy the SA. To prevent this we
ignore the message and wait for the one by the correct responder.
If the SA got redirected this would otherwise cause a reauthentication with
the original gateway. Reestablishing the SA to the original gateway, if e.g.
the new gateway is not reachable makes sense though.
We handle this similar to how we do reestablishing IKE_SAs with all CHILD_SAs,
which also includes the one actively queued during IKE_AUTH.
To delete the old SA we use the recently added ike_reauth_complete task.
To prevent the creation of the CHILD_SA we set a condition on the
IKE_SA. We also schedule a delete job in case the client does not
terminate the IKE_SA (which is a SHOULD in RFC 5685).
According to the mode-config draft there is no prefix sent for
IPv6 addresses in IKEv1. We still accept 17 bytes long addresses for
backwards compatibility with older strongSwan releases.
Fixes#1304.
When charon rekeys a CHILD_SA after a soft limit expired, it is only
deleted after the hard limit is reached. In case of packet/byte limits
this may not be the case for a long time since the packets/bytes are
usually sent using the new SA. This may result in a very large number of
stale CHILD_SAs and kernel states. With enough connections configured this
will ultimately exhaust the memory of the system.
This patch adds a strongswan.conf setting that, if enabled, causes the old
CHILD_SA to be deleted by the initiator after a successful rekeying.
Enabling this setting might create problems with implementations that
continue to use rekeyed SAs (e.g. if the DELETE notify is lost).
If it was necessary to pass the local certificates we could probably
clone the config (but we don't do that either when later looking for the
key to actually authenticate).
Passing auth adds the same subject cert to the config over and over
again (I guess we could also try to prevent that by searching for
duplicates).
The structs that make up a message sent to the kernel have all to be
aligned with XT_ALIGN. That was not necessarily the case when
initializing the complete message as struct.
Fixes#1212.
If there is no path to the other peer there is no point in trying to
send a NAT keepalive.
If the condition changes back and forth within the keepalive interval there
is a chance that multiple jobs get queued.
Tobias Brunner