Version 5.5.2¶

• Support of Diffie-Hellman group 31 using Curve25519 for IKE as defined by RFC 8031
  is provided by the new curve25519 plugin.

• Support of Ed25519 digital signature algorithm for IKEv2 as defined by draft-ietf-ipsecme-eddsa
  is provided by the new curve25519 plugin. Ed25519-based public key pairs, X.509 certificates and CRLs
  can be generated and printed by the pki tool.

• The new tpm libtpmtss plugin allows to use persistent private RSA and ECDSA keys bound
  to a TPM 2.0 for both IKE and TLS authentication. Using the TPM 2.0 object handle as keyid
  parameter, the pki --pub tool can extract the public key from the TPM thereby replacing the
  aikpub2 tool. In a similar fashion pki --req can generate a PKCS#10 certificate request signed
  with the TPM private key. Optionally the tpm plugin may be used as RNG.

• The pki tool gained support for generating certificates with RFC 3779 addrblock extensions.
  The charon addrblock plugin now dynamically narrows traffic selectors based on the certificate's
  addrblocks instead of rejecting non-matching selectors completely. This allows generic connections,
  where the allowed selectors are defined by the used certificates only.

• The optional bypass-lan plugin automatically installs and updates passthrough/bypass
  policies for locally attached subnets. This is useful for mobile hosts that are used in different
  networks that want to access local devices in these networks (e.g. printers or NAS) while
  connected to a VPN.

• A command injection vulnerability in the ipsec script was fixed, which was exploitable if unprivileged
  users were allowed to run the script via sudo (2ec6372f5a).
  Thanks to Andrea Barisani for reporting this.

• Several new features for the VICI interface and the swanctl utility were added:
  • Enumerating and unloading private keys and shared secrets (swanctl --load-creds now
    automatically unloads removed secrets)
  • Loading keys and certificates from PKCS#11 tokens or a TPM (refer to the documentation of
    cert<suffix> and token<suffix> sections in swanctl.conf)
  • The ability to initiate, install and uninstall connections and policies by their exact
    name (if multiple child sections in different connections share the same name)
  • Querying a specific pool
  • A command to initiate the rekeying of IKE and IPsec SAs
  • Public keys may be configured directly in swanctl.conf via 0x/0s prefix (actually works for
    certificates too)
  • The overhead of the VICI logger has been reduced as it now only does something if listeners
    are registered
  • Support for settings previously only supported by the old config files: DSCP, certificate
    policies, IPv6 Transport Proxy Mode, NT hash secrets, mediation extension

• In-place update of cached base and delta CRLs does not leave dozens of stale copies in cache memory.

• Support for handling IKEV2_MESSAGE_ID_SYNC notifies as responder (usually the original initiator
  of an IKE_SA) as defined in RFC 6311 was added. Some HA solutions use these notifies to set
  the new IKEv2 message IDs after a failover event (currently not our HA solution, though).

• By default, the IKE daemon keeps SAs on the routing path with addresses it previously used if that
  path is still usable. Enabling charon.prefer_best_path changes that and it will try more aggressively
  to update SAs with MOBIKE on routing changes using the cheapest path. This adds more noise, but
  allows to dynamically adapt SAs to routing priority changes, for instance, if some paths actually
  generate more costs than others (597e8c9e00).

• If MOBIKE is disabled and the local address is statically configured the daemon will now ignore any
  roaming events that might, otherwise, cause it to attempt to recreate the IKE_SA (be27e76869).

• Trap policies now use priorities from the same range as regular policies, which allows installing
  overlapping trap policies (#1243).

• When proposing transport mode the IKE daemon now always applies the hosts to the traffic selectors.
  It previously only did so if %dynamic was used as TS. However, that's not the case if wildcard trap
  policies are configured (no single remote address specified). Once traffic matched, the daemon proposed
  the configured remote TS as-as, which the responder then had to narrow down to its own local address.
  Some third-party implementations, however, reject such non-host TS for transport mode SAs (da82786b2d).

• For AH the kernel-netlink plugin now enables the correct 4 byte alignment (by default, the kernel
  uses an 8 byte alignment, which is mandatory for IPv6 but prohibited for IPv4, 965daa1df3).

• The kernel-netlink plugin now considers labels when selecting IPv6 addresses (#2138) and sets the
  NODAD flag for virtual IPv6 addresses to avoid issues with failing DAD (#2183).

• The receive buffer size used by the kernel-netlink plugin is now configurable (8a91729dfe).

• If route installation is disabled (charon.install_routes) the kernel-netlink plugin now uses a more
  efficient route lookup to determine source and next-hop addresses (558691b3b0).

• No mark is installed anymore on inbound IPsec SAs. So explicitly marking inbound traffic before
  decryption is not necessary anymore (067fd2c69c).

• The range from which SPIs for IPsec SAs are allocated by the kernel is now configurable.

• PSKs for IKEv1 connections are now first looked up based on configured identities of connections
  that match the IPs, before falling back to searching for PSKs for the IPs (#2223).

• The daemon now responds to DPDs for rekeyed IKEv1 SAs (#2090).

• charon-systemd now reloads strongswan.conf, the loggers and the plugins (that support it)
  when it receives a SIGHUP. The same may be achieved via VICI's reload-settings command, which
  previously did not reload the loggers.

• The forecast plugin used the incorrect port in UDP NAT-T rules (094a4d15cf).

• Validation via OCSP and CRLs can be disabled individually in the revocation plugin.

• RFC 5114 DH groups were removed from the default proposal (649537ee8d), they may be used if
  configured explicitly.

• A memory leak was fixed when CHILD_SA configs were updated via VICI (da1d5cd2e6).

• The plugin loader now correctly hashes registered plugin features (ac4942c3c3).

• Notes for developers:
  • Due to issues with VICI bindings that map sub-sections to dictionaries (e.g. Python)
    the CHILD_SA sections returned via list-sas now have a unique name. The original name
    of a CHILD_SA is returned in the name key of its section.
  • To simplify loading certificates via VICI when running on the same host as the daemon
    absolute paths to certificates (instead of their binary encoding) may be passed via
    cert<suffix> sections (file key).
  • The load-testconfig script now loads the configs from the source directory and pre-processes
    them properly (previously it was required to run do-tests once for the target scenario).