While combining the actions could cause duplicates (while the SA is
initiated, traffic might trigger the trap and the initiation of another
CHILD_SA), the previous commit should avoid most duplicates. If reuse_ikesa
is disabled, duplicates can't be prevented, though.
This could happen if an acquire is triggered while we respond to a
CREATE_CHILD_SA request from the peer, or if an acquire is triggered
while an IKE_SA (with its existing CHILD_SAs) is reestablished (also
with break-before-make reauthentication). Also catches multiple
manual initiations.
Note that this ignores the traffic selectors from acquires (narrowing to
them seems rare in practice anyway).
Duplicates can still get created if e.g. both peers initiate them
concurrently.
If a policy with IPComp template triggers an acquire, we get two, one for
an IPComp, one for ESP/AH SA. However, the triggering template of the trap
policy (where we get the reqid from), will be the same in both acquires,
IPComp, which we ignore, so no acquire was actually forwarded.
These are set via methods, which are not called again after migration
(e.g. when retrying due to INVALID_KE or when moving queued tasks), so we
don't want to clear these values.
This should fix this error thrown by autoreconf:
ld-elf.so.1: /usr/local/lib/perl5/5.32/mach/CORE/libperl.so.5.32: Undefined symbol "strerror_l@FBSD_1.6"
This should make the DoS limits (cookie_threshold[_ip] and block_threshold)
more accurate so that it won't be possible to create lots of jobs from
spoofed IP addresses before half-open IKE_SAs are actually created from
these jobs to enforce those limits.
Note that retransmits are tracked as half-open SAs until they are
processed/dismissed as the check only happens in checkout_by_message().
Increasing the count in process_message_job_create() avoids issues with
missing calls to track_init() before calling checkout_by_message() (e.g.
when processing fragmented IKEv1 messages, which are reinjected via a
process message job).
Because the global cookie threshold is higher than the per-IP block
threshold, it was previously possible for an attacker to block a legitimate
user by sending spoofed IKE_SA_INIT packets from that user's IP.
The timespan for requiring cookies is now also not extended anymore with
every IKE_SA_INIT received during the calm down period. Because this
allowed an attacker, after initially triggering the global cookie threshold,
to force cookies for all clients by sending just a single spoofed
IKE_SA_INIT every 10 seconds.
We keep track of reaching the per-IP threshold in segments of the hashed
IP addresses, so only a (random, due to chunk_hash()'s random key) subset
of clients will receive cookies, if single IPs are targeted.
The default global threshold is increased a bit.
If we are under attack and there are lots of requests, we might hit
the previous use count limit pretty quickly and may switch secrets multiple
times a second, which renders the 10 second default lifetime of COOKIEs
pointless and prevents legitimate clients from sending requests with valid
COOKIEs.
This happens for `/0` subnet masks. In practice, it's not an issue because
if `bytes` is 0, then so are `netbits`, `bits` and `mask`. So the two
incorrectly addressed array elements are not actually modified. The first
operation is a `&= 0xff` and the second a `|= 0`, so nothing changes.
But some tools might not consider the values and report this as undefined
behavior, which it technically is.
Such routes with a gateway that equals the peer's address are problematic
on FreeBSD. And since there is most likely a narrow route for the local
subnet anyway, the exclude routes would be redundant.
When installing routes based on remote traffic selectors, it can be
necessary to install an exclude route for the remote peer to avoid a
routing loop and continue to be able to reach it via IKE/ESP.
However, such routes are only necessary, if the routes we install don't
go via outbound interface. That's the case when using VIPs and routing
via TUN devices, or when using internal source IPs and routing via
their interfaces.
Installing such exclude routes if not necessary can cause issues on
FreeBSD (EINVAL when sending packets to the peer).
There is a conflict between atexit() handlers registered by OpenSSL and
some executables (e.g. swanctl or pki) to deinitialize libstrongswan.
Because plugins are usually loaded after atexit() has been called, the
handler registered by OpenSSL will run before our handler. So when the
latter destroys the plugins it's a bad idea to try to access any OpenSSL
objects as they might already be invalid.
Fixes: f556fce16b60 ("openssl: Load "legacy" provider in OpenSSL 3 for algorithms like MD4, DES etc.")
Closesstrongswan/strongswan#921
has_subject() already matches the identity against the subject DN and
all the SANs (it actually already did when this check was added with
c81147998619 ("Strictly check if the server certificate matches the TLS
server identity")).
The client already enforces that the server identity is contained in the
received certificate. But on the server, the referenced commit changed
the lookup from the configured (or adopted if %any was configured) client
identity to the subject DN of the received client certificate. So any
client with a trusted certificate was accepted.
Fixes: d2fc9b0961c6 ("tls-server: Mutual authentication support for TLS 1.3")
Closesstrongswan/strongswan#873
This adds some modifications to NAT-D in case the source IP can't be
determined before generating NAT-D notifies. If this happens when using
IPv4, a local NAT is faked (UDP-encap can be disabled later via MOBIKE
if no NAT is actually detected). If it happens when using IPv6, NAT-T
is disabled completely.
It also removes the old fallbacks for source NAT-D notifies, which were
generally unused but could lead to incorrect results in the above
scenario.
Closesstrongswan/strongswan#861
This can happen if an IKE_SA is initiated to a static IP before DHCP is
done. Instead of failing the initiation, we either fake a NAT situation
(for IPv4) or disable NAT-D (for IPv6 where NATs and UDP-encap are not
widely used or supported).
This also removes the old fallbacks to determine the source address(es).
A source address lookup is done in ike_sa_t::resolve_hosts() (wasn't the
case initially) and enumerating local IPs (which was added even earlier)
could still lead to issues if e.g. LAN addresses are available but the
WAN address that's later used is not yet (in which case only the responder
would detect a NAT and UDP-encap would be configured asymmetrically).
To force UDP-encap locally in case there is no actual NAT, we store this
as COND_NAT_HERE instead of COND_NAT_FAKE. This ensures DPDs will contain
NAT-D notifies and we can later remove the state via MOBIKE. We trigger
a MOBIKE update after such a DPD by registering a changed NAT mapping after
checking for a disappearing local NAT, which is very unlikely to happen
outside of a MOBIKE update (where that flag is not checked).
On the recently updated 2019 image, autoreconf is not found anymore, as
recent versions of msys2 don't ship autools with base-devel aymore, so
install the autotools package explicitly.
The commit mentioned below adds an AES-GCM default proposal for ESP. That
proposal does not include any ESN or non-ESN transform to indicate if
extended sequence numbers are supported.
A standards-compliant peer will include one or more ESN support transforms,
and will be unable to select this proposal due to a proposal mismatch.
Fix the default AES-GCM proposal by adding a NO_ESN algorithm. While ESN has
been supported in the Linux kernel for a while, having it in the default
proposal can be problematic with kernel-libipsec or on other platforms.
Fixes: c7bef954eec6 ("proposal: Add AES-GCM to the ESP default AEAD proposal")
Closesstrongswan/strongswan#868
strongSwan logs all syslog messages using LOG_INFO for historical reasons,
regardless of the strongSwan loglevel used producing the log message.
In some setups with advanced logging infrastructure, it may be feasible
to be more verbose when logging in strongSwan, but then filter messages
on the syslog server. While this may be possible by custom syslog filtering
rules matching the log level included with the log_level setting, this is
not super convenient.
So add a new map_level setting, which can map strongSwan loglevels to
syslog loglevels. By default this is disabled, keeping the existing
behavior. If enabled, it maps strongSwan loglevels to syslog loglevels
at a given syslog loglevel offset.
Closesstrongswan/strongswan#859
RFC3779 requires to validate the addrblocks of issuer certificates strictly,
that is, they must contain the extension and the claimed addrblock, up to
the root CA.
When working with third party root CAs that do not have the extension,
this makes using the plugin impossible. So add a depth setting that limits
the number of issuer certificates to check bottom-up towards the root CA.
A depth value of 0 disables any issuer check, the default value of -1
checks all issuers in the chain, keeping the existing behavior.
Closesstrongswan/strongswan#860
Without this, the authentication succeeded if the server sent an early
EAP-Success message for mutual, key-generating EAP methods like EAP-TLS,
which may be used in EAP-only scenarios but would complete without server
or client authentication. For clients configured for such EAP-only
scenarios, a rogue server could capture traffic after the tunnel is
established or even access hosts behind the client. For non-mutual EAP
methods, public key server authentication has been enforced for a while.
A server previously could also crash a client by sending an EAP-Success
immediately without initiating an actual EAP method.
Fixes: 0706c39cda52 ("added support for EAP methods not establishing an MSK")
Fixes: CVE-2021-45079
