We do something similar in reestablish() for break-before-make reauth.
If we don't abort we'd be sending an IKE_AUTH without any TS payloads.
References #2430.
This causes problems e.g. on Android where we handle the alert (and
reestablish the IKE_SA) even though it usually is no problem if the
peer retries with the requested group. We don't consider it as a
failure on the initiator either.
In case we send retransmits for an IKE_SA_INIT where we propose a DH
group the responder will reject we might later receive delayed responses
that either contain INVALID_KE_PAYLOAD notifies with the group we already
use or, if we retransmitted an IKE_SA_INIT with the requested group but
then had to restart again, a KE payload with a group different from the
one we proposed. So far we didn't change the initiator SPI when
restarting the connection, i.e. these delayed responses were processed
and might have caused fatal errors due to a failed DH negotiation or
because of the internal retry counter in the ike-init task. Changing
the initiator SPI avoids that as we won't process the delayed responses
anymore that caused this confusion.
When requiring unique flags for CHILD_SAs, allow the configuration to
request different marks for each direction by using the %unique-dir keyword.
This is useful when different marks are desired for each direction but the
number of peers is not predefined.
An example use case is when implementing a site-to-site route-based VPN
without VTI devices.
A use of 0.0.0.0/0 - 0.0.0.0/0 traffic selectors with identical in/out marks
results in outbound traffic being wrongfully matched against the 'fwd'
policy - for which the underlay 'template' does not match - and dropped.
Using different marks for each direction avoids this issue as the 'fwd' policy
uses the 'in' mark will not match outbound traffic.
Closesstrongswan/strongswan#78.
Initiation might later fail, of course, but we don't really
require an IP address when installing, that is, unless the remote
traffic selector is dynamic. As that would result in installing a
0.0.0.0/0 remote TS which is not ideal when a single IP is expected as
remote.
This splits the SA installation also on the initiator, so we can avoid
installing the outbound SA if we lost a rekey collision, which might
have caused traffic loss depending on the timing of the DELETEs that are
sent in both directions.
This way we get the log message in stroke and swanctl as last message
when establishing a connection. It's already like this for the IKE_SA
where IKE_ESTABLISHED is set after the corresponding log message.
Fixes#2364.
If we find a redundant CHILD_SA (the peer probably rekeyed the SA before
us) we might not want to delete the old SA because the peer might still
use it (same applies to old CHILD_SAs after rekeyings). So only delete
them if configured to do so.
Fixes#2358.
The correct truncation is 128-bit but some implementations insist on
using 96-bit truncation. With strongSwan this can be negotiated using
an algorithm identifier from a private range. But this doesn't work
with third-party implementations. This adds an option to use 96-bit
truncation even if the official identifier is used.
After deleting a rekeyed CHILD_SA we uninstall the outbound SA but don't
destroy the CHILD_SA (and the inbound SA) immediately. We delay it
a few seconds or until the SA expires to allow delayed packets to get
processed. The CHILD_SA remains in state CHILD_DELETING until it finally
gets destroyed.
The responder has all the information needed to install both SAs before
the initiator does. So if the responder immediately installs the outbound
SA it might send packets using the new SA which the initiator is not yet
able to process. This can be avoided by delaying the installation of the
outbound SA until the replaced SA is deleted.
Using install() for the inbound SA and register_outbound() for the
outbound SA followed by install_policies(), will delay the installation of
the outbound SA as well as the installation of the outbound policies
in the kernel until install_outbound() is called later.
Much like in commit a68454b, we now use a global atomic counter to keep
track of the number of IKE_SAs currently registered. This should improve
scalability for a large number of segments even more.
Signed-off-by: Thomas Egerer <thomas.egerer@secunet.com>
This provides a solution for configs where there is e.g. a catch-all %any
PSK, while more specific PSKs would be found by the identities of configs
that e.g. use FQDNs as local/remote addresses.
Fixes#2223.
Memory is allocated with calloc, hence set to zero, thus assigning the
numerical value 0 is not required.
Signed-off-by: Thomas Egerer <thomas.egerer@secunet.com>
Some devices always use the oldest IKE_SA to send DPDs and will delete
all IKE_SAs when there is no response. If uniqueness is not enforced
rekeyed IKE_SAs might not get deleted until they expire so we should
respond to DPDs.
References #2090.
When multihomed, a setup might prefer to dynamically stay on the cheapest
available path by using MOBIKE migrations. If the cheapest path goes away and
comes back, we currently stay on the more expensive path to reduce noise and
prevent potential migration issues. This is usually just fine for links not
generating real cost.
If we have more expensive links in the setup, it can be desirable to always
migrate to the cheapest link available. By setting charon.prefer_best_path,
charon tries to migrate to the path using the highest priority link, allowing
an external application to update routes to indirectly control MOBIKE behavior.
This option has no effect if MOBIKE is unavailable.
Disabling MOBIKE and statically configuring a local address should be
enough indication that the user doesn't want to roam to a different
address. There might not be any routes that indicate we can use the
current address but it might still work (e.g. if the address is on an
interface that is not referenced in any routes and the address itself
is neither). This way we avoid switching to another address for routes
that might be available on the system.
We currently don't make much use of COND_STALE anyway when MOBIKE is not
enabled, e.g. to avoid sending DPDs if the connection is seemingly down.
With MOBIKE enabled we don't exactly check that state but we do don't
send DPDs if there is no route/source address available.
Tobias Brunner